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GENESYS 2003 Enterprise Simulation

1. Port Size 20 os Rot Snap Angle so 20 Remove Multi Place Parts 50 Add New Default Viahole Layers Top Layer PB TOP METAL Bottom Layer E Bottom Cover Cancel Apply The following entries are especially relevant to EMPOWER Show EMPOWER Grid Turning on this checkbox forces LAYOUT to display the rectangular EMPOWER grid It also allows different grid spacings in the X and Y 223 Simulation 224 dimensions I zs strongly recommended to turn this checkbox on whenever you are creating a layout for EMPOWER Grid Spacing X and Grid Spacing Y These control the cell size for the EMPOWER run as well as the grid snap feature in LAYOUT When using the EMPOWER Grid Style there will be LAYOUT snap points between each grid line which allow lines to be centered between two grid points if necessary They are often referred to as dx and dy and should be small with respect to a wavelength at the maximum frequency to be analyzed preferably less than wavelength 20 and always less than wavelength 10 Box Width and Box Height These are the box size for EMPOWER simulation They cotrespond directly to the SIZE statement in the TPL file The number of cells across the box equal to Width or Height divided by Grid Spacing X or Y is displayed for your convenience and can be changed to adjust the page width Note Any metal put down completely outside the box will be ignored by EMPOWER This can be
2. Desired and Undesired spectrums As with a real circuit board all signal sources propagate their signals to every node in the system since perfect isolation is unrealizable with real components Consequently real sionals propagate in both directions at every node SPECTRASYS follows this same model and signals travel in both directions at a every node However the user is typically only interested in the RF power traveling in a particular direction For example if the user created a schematic of a single conversion super heterodyne receiver the cascaded gain for the primary receive path would only make sense looking in the direction from the receiver 85 Simulation 86 front end to the IF output The direction of the LO radiation along the path from the LO to the receive antenna port would be in a direction opposite that of the received signal As a result the Desired Spectrum for the received signal would be in the forward direction from the receiver front end to the IF output and the Undesired Spectrum would be any other signal that didn t originate from the receiver front end that is traveling in the reverse direction However looking at the signals along the LO radiation path the LO signals would be the Desired Spectrum and the received signals would be the Undesired Spectrum All signals that are members of the Desired Spectrum and Undesired Spectrum are also members of the Tot
3. NOTE Only the first 2 adjacent channels on either side of the reference channel 1s listed in the Measurement Wizard However there is no restriction on the Adjacent Channel Number Values Real value in MHz Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators None Examples Measurement Result in graph Smith chart Result on table optimization or yield ACFL1 ACFL1 ACFL1 Not available on Smith Chart This measurement is the noise contribution of each individual stage in the main channel along the specified path as shown by ANT n CNF n CNF n 1 dB where AN 0 0 dB n stage number Measurements SPECTRASYS This measurement is simply the difference in the Cascaded Noise Figure measurement between the current node and the previous node This measurement is very useful and will help the user identify the contribution to the noise figure by each stage along the path See the Cascaded Noise Figure measurement to determine which types of signals are included or ignored in this measurement Values Real value numeric Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DB AN stage noise figure in dB Real MAG AN numeric value of the stage noise figure Real Examples Measurement Result in graph Smith chart Result on table optimization or y
4. Note For all dialog boxes be sure that your screen looks exactly like the boxes shown in the figures Note In EMPOWER the layout s box dimensions are used to define the bounding box The box dimensions are shown below Box Width was chosen as 425 the width of the filter since there are two 200 mil lines and a stub width of 25 mils The filter height 1s 275 mils including the stub length and series line width The box height was chosen as 600 mils to give plenty of spacing on either side of the filter This minimizes wall interference in the filter s frequency response Create New Layout X General Associations General Layer EMPOWER Layers Fonts Units Millimeters Mils Custom 0 025 Object Dimensions Line Width 25 Box Settings The UNITS box at left show units Grid Spacing x 125 M Show Box Grid Spacing Y fi 2 5 Y Show Grid Dots M Show EMPOWER Grid Box Width x 425 fas Cells Box Height Y s00 fas Cells Designs to include Design Zz Pad Width 50 Origin fo o Drill Diameter 40 Drawing Options Port Size 25 Widths Rot Snap Angle so 25 30 Remove TT Multi Place Parts dd New Default Viahole Layers Top Layer oO TOP METAL Bottom Layer E Bottom Cover The EMPOWER erid settings for this example are shown in the upper right above EMPOWER simulation time is greatly reduced if dimensio
5. Linear magnitude and angle in range of 180 to 180 Real Other Operators MAGI ANG ANG360 IM MAGANG360 Examples Measurement Result in graph Smith chart Result on table optimization or yield GM real imaginary parts of gamma for all ports GM1 RE GM1 RECT GM1 The Simultaneous Match Admittance is a complex function of frequency and is available for 2 port networks only This is the value of admittance which must be seen at port 7 to achieve a simultaneous match at both input and output Values Complex value versus frequency Simulations Linear Default Format Table RECT Graph RE Smith Chart GMz Commonly Used Operators Operator Description Result Type RECT YM1 real imaginary parts Real RE YMI1 real part Real MAGANG ZM2 Linear magnitude and angle in range of 180 to 180 Real Other Operators MAGI ANG ANG360 IM MAGANG360 Examples 155 Simulation 156 Measurement Result in graph Smith chart Result on table optimization or yield YM real imaginary parts of admittance for all ports ZM1 RE ZM1 RECT ZM1 The Maximum Available Gain measurement is a real function of frequency and is available for 2 port networks only For conditions where the stability factor K is greater than zero i e the system is unconditionally stable then GMAX Sa S12 K sqrt K 2 1 If K lt 1 then GMAX is set to the maximum stable gain therefore GMAX
6. Note The walkthrough at this point is saved in Examples SPECTRASYS Walkthrough 2 Add Simulation WSP Level Diagrams Another tool in SPECTRASYS is the level diagram To create a level diagram 1 You must first add a path to the system simulation Double click on System1 in the workspace window 2 On the Paths tab click Add Path Enter the beginning path node 1 and ending path node 2 Enter the name Forward Note You can also click Add Primary Paths to automatically add all paths Click OK Right click on the Outputs tab in the workspace window Select Add Rectangular Graph Enter the name Level diagram Click Measurement wizard to add a new measurement oe A A Select Simulation System1 Sch1 Path Forward and press Next 21 Simulation 8 Choose measurement CGAIN Cascaded Gain and press Finish Press OK You will see a level diagram similar to the one shown below This diagram shows the total cascaded gain through the system at each node BP Level Diagram Workspace test DAC AIN DB CGAIN Note The walkthrough at this point is saved in Examples SPECTRASYS Walkthrough 3 Level Diagram WSP System Simulation Parameters Tuning Parameters Like the rest of the GENESYS environment SPECTRASYS features real time tuning In addition to the tuning of element values all parameters in the system simulation dialog box can be tuned 1 Double click System1 in the workspace wi
7. Other Operators MAGI ANG ANG360 IM MAGANG360 Examples Measurement Result in graph Smith chart Result on table optimization or yield H22 RE H22 real part of H22 RECT H Shows real imaginary parts of all H Parameters MAG H21 Linear Magnitude of H21 Linear Magnitude of H21 H Shows real imaginaty parts of all H Parameters x Not available on Smith Chart This Y parameter or admittance parameter measurements are complex functions of frequency The frequency range and intervals are as specified in the Linear Simulation dialog box The Y parameters for an n port network are of the form YP fori j equal 1 2 n For a two port network the equations relating the input voltage V1 and current l to the output voltage V2 and current gt are Measurements Linear l YP11 Vi YP12 Va In YPa1 Vi YP2 Va Values Complex matrix versus frequency Simulations Linear Default Format Table RECT Graph RE Smith Chart none Commonly Used Operators Operator Description Result Type RECT YP11 real imaginaty parts Real RE YP22 real part Real MAGANG YP21 Linear magnitude and angle in range of 180 to 180 Real Other Operators MAGI ANGI ANG360 IM MAGANG360 Examples Measurement Result in graph Smith chart Result on table optimization or yield YP22 RE YP22 real part of YP22 RECT YP Shows real imaginaty parts of all Y Parameters MAG YP21 Linear Magnitude of
8. S2 3x 2x53 Source2 second source 3rd Harmonic of a 2nd Harmonic of Source3 third source Sometimes the frequency of the equation may be negative In this case the user should simply use the absolute value of this frequency equation Path The path of the spectral component can be determined by examining the comma delimited sequence of node numbers short form or reference designators long form which identify the node or element where the spectrum was created and the node or element sequence that the signal took to arrive at the destination node The first node number or reference designator after the closing frequency equation bracket shows the reference designator or node number where the spectrum first appeared or was created The subsequent node numbers or reference designators indicate the path that the spectral component took to arrive at the node under investigation Path Examples S1 2xS2 6 7 8 12 5 2 Would indicated that a third order intermod S1 2xS2 was created at node 6 then traveled through nodes 7 8 12 5 and then arrived at node 2 which is the current node under investigation NOTE Currently mixer sum and difference frequencies and the LO frequency used for the frequency translation are not supported in the spectral component identification However the input source to the mixer is identified and the user can figure out the actual output frequency of the mixer used for the creation of the spectral compone
9. Su 141 Simulation 142 NFT GOPT YOPT ZOPT RN NFMIN ZMz YMz GMz K B1 SB1 SB2 NCI GA GP GU1 GU2 Effective noise input temperature Optimal gamma for noise Optimal admittance for noise Optimal impedance for noise Normalized noise resistance Minimum noise figure Simultaneous match impedance at port 7 Simultaneous match admittance at port 7 Simultaneous match gamma at port 7 Stability factor Stability measure Input plane stability circle Note Filled areas are unstable regions Output plane stability circle Note Filled areas are unstable regions Constant noise circles shown at 25 5 1 1 5 2 2 5 3 and 6 dB less than optimal noise figure Available gain circles Power gain circles Unilateral gain circles at port 1 Unilateral gain circles at port 2 Can only be used on 2 port networks Gain circles are only available for 2 port networks Circles are shown at 0 1 2 3 4 5 and 6 dB less than optimal gain In GA and GP if K lt 1 then the OdB circle is at GMAX and the inside of this circle is shaded as an unstable region Linear real DBANG RECT RECT Linear real dB real RECT RECT DBANG Linear real Linear real None Circle None Circle None Circle None Circle None Circle y Z one Circle None Circle GOPT GOPT GOPT SB1 Circles SB2 Circles NCI Circles GA Circles GP Circles
10. Type a new value for the capacitor or tune using Page Up Page Down keys or the spin buttons The GENESYS screen below is shown after tuning the capacitors from 0 55 pF to 1 2 pF The response shown on the left in this figure is the SUPERSTAR linear simulation response The EMPOWER data is combined with the lumped elements in the rightmost response 4 GENESYS 7 0 Pala Es File Edit View Workspace Actions Tools Synthesis Window Help 2s S 08 AR Tra T E E lt Designs E F2000 Schema 8 Layout Layout H E Simulations Data Si EM Layoutl 33 Linear 1400 tc Dutputs FA Circuit Simulatior AH Combined Simul 5 2 Equations E E3 Substrates EF Default 4 sle 7 Fen ee 2000 2000 Freq MHz Freq MHz gt DB S21 DB S21 DB S11 215 EMPOWER Basics A major part of any electromagnetic simulation is to break the problem down into manageable size pieces that allow an approximation of Maxwell s equations to be solved Electromagnetic simulators traditionally fall into three major categories 2 D 3 D and 2 1 2 D 2 D SIMULATORS 2 D simulators can only analyze problems that are infinitely continuous in one direction Ideal transmission lines and some waveguide problems are practical problems which fall into this category A 2 D simulator will analyze a slic
11. E RF and Microwave Design Software E GENESYS 2003 Enterprise Simulation Eagleware Corporation owns both the GENESYS software program suite and its documentation No part of this publication may be produced transmitted transcribed stored in a retrieval system or translated into any language in any form without the written permission of Eagleware Corporation Copyright 1985 2003 Eagleware Corporation All rights reserved Eagleware Corporation 635 Pinnacle Court Norcross GA 30071 USA Main Phone 678 291 0995 Sales Phone 678 291 0259 Support Phone 678 291 0719 Fax 678 291 0971 Printed in the United States of America Version 2003 first printing August 2003 Table Of Contents Sag 10 EHH CO Ot A tie dei caia 1 Which Simulator Soul al Ue deu 1 DC Analysis Verne Transistor Parametros 5 DEAnalsis Diasino the Irans tOr ai diodos 8 Titre at Sitam il ato trey Ata LG oaa aca oose ede cki canst E 10 HARBEC analysis Walkthr Oui sarna 12 Creatine A ochena E aena E N T 17 Addins a SPEC TRIAS VS SIMULA iaa 17 Level Dao enp a a ea uaastusaecunsacarsdonssangeycoteyateeaneausecemtanaet 21 System Simulation Parameters Tuning Parameters risas dos 22 A OLA 23 KATAN A 26 M kiple senal A N 2l ONE diia 29 OEM odiada 31 Pinear Simulation Properties rias is 31 PAE AA AA A dae damceinnan a eaten oes 32 OVET EMI 32 SPANDI IC Si aa E R T 32 A RO 34 Moro Rata 35 CARA a NM S Gir ste a ces seh sac cutee atone secu siiiss ue cu
12. Measurements There are three large signal S parameters measurements They are described as follows LargeSdb output port input port Magnitude of Large Signal S Parameters in dB i e LargeSdb 2 1 LargeSAng output port input port Angle of Large Signal S Parameters in degrees Le LargeSAng 2 1 LargeS output port input port Rectangular value of Large Signal S Parameters i e LargeS 2 1 Steps for Large signal S Parameter Analysis 1 Create a schematic with a PAC AC Power input at the input port Make sure source frequencies and power levels have been specified 2 Create variables that are intended to be swept Le frequency power etc in the equations window 3 Add a HarBEC simulation 4 Add parameters sweeps of the desired variables such as frequency or power These sweeps ate added under the Simulation Data workspace folder 5 Adda graph Graphs are added under the Outputs workspace folder 6 In the graph select the correct sweep to use then type the measurement such as LargeS 2 1 for S21 Currently the measurement wizard cannot be used to add large signal S Parameters For an example of Large Signal S Parameters choose File Open Example then load Amplifiers Large Signal S Parameters 165 Measurements Load Pull Load Pull Contours GENESYS can draw load pull data contours such as the one shown below from data contained in Focus and Maury Microw
13. Other gain definitions include the power gain Gp and the available power gain Ga Gp P delivered to load P input to network Ga P available from network P available from source The S parameter data for the network is measured with a source and load equal to the reference impedance If the network is not terminated in the reference impedance Gt can be computed from the reflection coefficients of the terminations on the network and the S parameters of the network At this point we have multiple sets of reflection coefficients those of the terminations and S11 and 22 of the network To avoid confusion the termination reflection coefficients are given a different symbol G The transducer power gain with the network inserted in a system with arbitrary source and load reflection coefficients is 4 Gt Sa A Rs RL 3 SURYA S22Rr S21S12RrRs where Rs reflection coefficient of the source R reflection coefficient of the load If and are both zero then Gt S21 ot Gt dB 20log S21 S21 dB Therefore when a network is installed in a system with source and loads equal to the reference impedance S21 is the network transducer power gain in decibels Because S11 and S22 of a network are not in general zero a portion of the available source power is reflected from the network input and is dissipated in the source The insertion of a lossless matching network at the input and or output of the network coul
14. Recalculate Now Starts a simulation if required If the simulation is up to date no changes have been made to the design since the last simulation this command will be gray and the simulation will not be re run To force a new simulation either make some change in the design or select Delete internal simulation data Mark results up to date Changes the status of a simulation to current Use this feature when a change has been made to the design that does not affect the simulation results such as changing a value and then changing it back HARBEC DC amp Harmonic Balance Automatically Calculate Toggles on or off the state that starts a simulation any time a change is made to the design Active for Opt Yield Recalc Toggles on or off the simulation status If not Active the simulation will not be run when during optimization yield analysis or when the recalculation button is clicked Write all internal data Creates a set of external ASCII files containing the simulation netlist the simulator log messages raw simulation results and simulation errors Delete internal simulation data Discards all existing calculated results Selecting this menu will cause the simulator to start from a new state on its next run Properties Opens the HARBEC Options dialog box Show HarBEC monitor window Opens a window that contains detailed information about the HARBEC simulation run Only available for harmonic balance simul
15. System Simulation Dialog Box A Channel Frequency exists for each node along the specified path Consequently each node along the path will have the same Channel Frequency until a frequency translation element such as a mixer or frequency multiplier is encountered SPECTRASYS automatically deals with frequency translation through these elements The individual mixer parameters of Desired Output Sum or Difference and LO Injection High of Low ate used to determine the desired frequency at the output of the mixer The Channel Frequency is a critical parameter for SPECTRASYS since most of the measurements are based on this parameter If this frequency is incorrectly specified then the user may get unexpected results since many measurements are based on this frequency The easiest way to verify the Channel Frequency that SPECTRASYS is using is to look at this measurement in a Table Measurements SPECTRASYS Values Real value in MHz Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators None Examples Measurement Result in graph Smith chart Result on table optimization or yield CF CF CF Not available on Smith Chart The Offset Channel Frequency and Offset Channel Power are very useful measurements in SPECTRASYS These measurements give the user the ability to create a user defined channel relative the the main channel The
16. This is the channel defined by the image frequency of the first mixer and the channel bandwidth For example the channel 1000 to 1001 MHz would have an image channel of 800 to 801 MHz if an LO Frequency of 900 MHz was specified for the mixer LO Local Oscillator Offset Channel User defined channel relative to the main channel For example an offset channel specified as 50 MHz for a main Channel Frequency of 125 MHz would result in a channel of 75 MHz Y Channel Bandwidth OIP3 Output Third Order Intercept LO Side Injection The relative indication of the LO frequency with respect to the mixer RF frequency The RF frequency can be either the input or the output of the mixer 55 Simulation 56 For example 1f the mixer took a 1000 MHz and down converted it to a 100 MHz IF then an LO frequency of 900 MHz is Low Side LO injection and an LO frequency of 1100 MHz is High Side LO injection MDS Minimum Detectable Discernable Signal which is equivalent to 174 dBm Hz System Noise Figure 10 Log Bandwidth Non Coherent Signal Two signals which are not at constant phase offset are not coherent Path The course a signal takes from the source node to the destination node RBW Resolution Bandwidth SFDR Spurious Free Dynamic Range Undesired Spectrum Any spectrum flowing in a direction opposite of the path direction System Simulation Parameters General Tab This page sets the genera
17. Values Real value in Watts Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DBM ACPU2 2nd upper adjacent channel power in dBm Real MAG ACPU2 magnitude of the 2nd upper adjacent channel power in Watts Real Examples Measurement Result in oranh Smith chart Result on table 169 Simulation 170 optimization or yield DBM ACPU2 DBM ACPU2 DBM ACPU2 MAG ACPU2 MAG ACPU2 MAG ACPU2 Not available on Smith Chart This measurement is the frequency of the specified adjacent channel All adjacent channel frequencies are relative to the main Channel Frequency Consequently channels exist above and below the main reference channel frequency The user can specify which side of the main or reference channel that the adjacent channel is located on and also the channel number The channel number is relative to the main or reference channel Therefore channel 1 would be the first adjacent channel channel 2 would be the second adjacent channel and so on U Upper Side L Lower Side n Channel Number any integer gt 0 For example ACFU1 if the first adjacent channel above that specified by the Channel Frequency If CF was 100 MHz and the channel bandwidth was 1 MHz then the main channel would be 99 5 to 100 5 MHz Consequently then ACFU1 would then be the channel 100 5 to 101 5 MHz and ACFL1 would be 98 5 to 99 5 MHz
18. zz 0 A close up is shown below where you can see how metal and ports are mapped onto the borders of the cells The presence of metal or conductors along the grid causes 222 EMPOWER Basics EMPOWER to close the connections along the grid The presence of an EMPort causes the line to be opened creating an open circuit which turns into a port in the final data file Ex Jt Ey Ey Ez Jy Y rhe p Extx E a E Note It is possible to make a line so narrow that it maps to one border between cells zero cells wide This is legal but is not normally recommended and should be used only for very high impedance lines where accuracy is not important such as DC power lines The grid and the box are controlled with parameters in the Preferences box from the LAYOUT File menu The Dimensions Tab shown below ts as it was setup for the microstrip bend above Create New Layout X General Associations General Layer EMPOWER Layers Fonts Units Box Settings The UNITS box at left show units Milimeters Grid Spacing X 20 Y Show Box oa Tan Grid Spacing Y 20 M Show Grid Dots M Show EMPOWER Grid Box Width Xx 300 ft 5 Cells Designs to include design Sent Layout jo Object Dimensions Line Width 30 Box Height Y 200 fr 5 Cells Pad Width feo Origin o A o Drill Diameter 50 Drawing Options
19. 1 0 that contains only one unit element corresponding to the specified input The other elements of the vector are zeros Reflected waves vector B are calculated from the equation B S A Then the simulator defines normalized voltages and currents in mode space denormalizes them and restores the grid currents and voltages inside regions corresponding to all input surface current regions Finally using the input region variables the program calculates non zero grid currents lg for strip like structures or voltages Vg for slot like structures The grid currents and voltages are locally defined model currents and voltages see the Theory section and their units are Amperes and Volts accordingly The grid currents and voltages together with their coordinates on the grid are stored in the EMV file The same EMPOWER Viewer and Antenna Patterns data can be written in the self documented text file with the extension PLX The viewer reads the EMV file and to displays data Note that the initial current voltage distribution is a model representation and 1s treated using complex number conventions The currents voltages are complex quantities and harmonic functions of time So their magnitudes are maximal values for the excited wave period The real component corresponds to instantaneous values of currents and their phases reflect the phase delays of currents at the initial time t 0 Using these initial data the current distribution i
20. 1 Soe where Gtu unilateral transducer power gain When both ports of the network are conjugately matched and S12 0 Gtu Sa 2 1 Si 2 1 S213 The first and third terms indicate the gain increase achievable by matching the input and output respectively If S11 or S22 approach 1 substantial gain improvement is achieved by matching Matching not only increases the network gain but reduces reflections from the network When network gain flatness across a frequency band is more desirable than minimum reflections the lossless matching networks are designed to provide a better match at frequencies where the two port gain is lower By careful design of amplifier matching networks it is possible to achieve a gain response flat within fractions of a decibel over a bandwidth of an octave or mote Gain Circles When the device is complex conjugately matched the transducer gain is Gmax and if the device is terminated with the same resistance used to measure the device S parameters the transducer gain is S21 The gain with arbitrary terminations can be visualized on the Smith chart using gain circles SUPERSTAR plots three forms of gain circles transducer gain unilateral circles GU1 for the input network and GU2 for the output network power gain output network circles GP and available gain input network circles GA Shown below are the input and output unilateral transducer gain circles GU1 and GU2 of the Avantek AT10135 Ga
21. A A A a a O Se un K _ KA lt _ o__ eco ee PP o Ly A Cf o o rr aea LLL eq M e amMM _ a os C m A A o U ee O O E A E E E T A E o ay __z_ roo Se oa MM C PF SY A SS EN M a aaao aamu a e a a a a a a E E A ES AA ee E SA A C O O O A A o e o SY SS a A A E iI A lt lt _ _ _ __ ___ __ _ RN a Ao eo SE A o o A aMMM A o OS _ zdlWwaa e DBM P2 101 x Workspace 7 Multiple Signals E Input Spectrum Lala a e DBM P1 Note The completed walkthrough is saved in Examples SPECTRASYS Walkthrough 7 Multiple Signals WSP 28 Walkthrough SPECTRASYS SPECTRASYS is a spectral domain system simulator Because of its unique implementation it has several advantages over traditional simulators The main focus of SPECTRASYS is to aid the user is analyzing and optimizing the RF performance of a chosen architecture which consists of two or more RF blocks or elements The best way to think about SPECTRASYS is to compare the SPECTRASYS schematic ot block diagram to a circuit board and the SPECTRASYS simulation graph to a spectrum analyzer Just like a circuit board SPECTRASYS propagates every source and derived spectral component harmonics intermods spurs etc to every node in the system The graph c
22. BPF_BLITTER_1 FLO 8 MHz FHI 12 MHz N 5 IL 0 dB LO Port 3 APASS 3 dB EE o Be Unlike a spectrum analyzer on the SPECTRASYS composite plot we can actually distinguish the direction of travel of all spectral components Furthermore a trace that represents the total from all directions in a node is represented By simply placing the mouse over the trace the user is able to identify which direction the signals are traveling by seeing which element they are coming from Think of this is as an N way directional coupler with infinite directivity so that we only see the signals traveling in the direction of interest All of these signals from each direction of travel is an independent trace on the composite spectrum plot For example if we had three elements connected to a node we would see signals traveling from each of these elements For the example shown the components in the RF input are at 90 and 100 MHz Notice that the 90 MHz component is identified as from source S2 i e the LO drive The leakage path is from the LO input port S2 or node 3 through nodes 7 and 4 1 e the mixer LO to RF isolation and then through attenuator ATTN_1 The power of 25 dBm is the result of the LO power of 10 dBm attenuated by 5 db and passing through the mixer isolation path with 30 db 89 Simulation BE Composite Workspace composite_spectrum ERAS eae H Composite Spectrum at Output Node 1110 MHz ad 173 9134 Total trom Po
23. Linear magnitude and angle in range 0 Complex Complex to 360 DBANG dB magnitude and angle in range 180 Complex Complex to 180 DBANG360 dB magnitude and angle in range 0 to Complex Complex 360 RECT Rectangular real imag Complex Complex MAGJ Linear magnitude Real Complex Real ANGI Angle in range 180 to 180 Complex Real ANG360 Angle in range 0 to 360 Complex Real REI Real part of complex measurement Complex Real IM Imaginary part of complex Complex Real measurement DBI dB Magnitude Real Complex Real GD Group delay Complex Real QLI Loaded Q QL 2 pif GD Complex Real 2 TIME Converts Frequency domain to Time Complex Real For post processing equation purposes the magnitude is in the real part of the result and the angle is in domain via inverse Fourier Transform Intended for use with Voltage Current to get time waveforms the complex part of the result Only the following parameters can be displayed in dB form GM E GOPT GMAX NF NEMIN and NMEAS Note that not all operators can be used with all measurements The Measurement must be column above indicates which type of parameter each operator can use For example ANGI Angle cannot be used with a real valued parameter such as GMAX so ANG GMAX is not allowed Measurements Overview Note All available measurements and their operators for a given circuit or sub circuit with their appropriate syntax are sho
24. Linear or Electromagnetic 1 Should I use both circuit theory and EM simulation Circuit theory simulation in GENESYS is amazingly fast and interactive No other program at any price approaches the speed of GENESYS EMPOWER simulations are more accurate and do not require the use of specific geometric objects for which circuit models have been developed EM simulation complements rather than replaces circuit theory simulation Overview 2 What is the highest frequency used in the circuit If below about 1 GHz lumped elements are often used in place of distributed elements In this case the final board layout usually won t add any significant parasitics or coupling concerns Often however customers use EMPOWER to simulate the final board layout to make sure that it doesn t differ from the linear simulation 3 How big is the circuit If the circuit itself is very small compared to a wavelength at the highest frequency of concern electromagnetic simulation may not be needed This is because resonances occur at quarter wavelengths and circuits much smaller than this usually behave as predicted by a complete linear simulation 4 Does the circuit have non standard metal shapes patterns or geometries If so electromagnetic simulation may be the only option EMPOWER can simulate any arbitrary shape such as ground plane pours A linear simulator requires a netlist or schematic to describe the circuit so models would have to exist for t
25. MDS and the input power which would cause the third order intermods to be equal to the MDS The MDS is the smallest signal that can be detected and will be equivalent to the receiver noise floor with a signal to noise ratio of 0 dB In other words the MDS 174 dBm Hz System Noise Figure 10 Log Channel Bandwidth See the Input Third Order Intercept and Channel Noise Power measurements to determine which types of signals are included or ignored in this measurement Values Real value in Watts Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DBI SFDR spurious free dynamic range in dB Real MAGJISFDR magnitude of the spurious free dynamic range in Watts Real Measurements SPECTRASYS Examples Measurement Result in graph Smith chart Result on table optimization or yield DBI SFDR DB SFDR DBI SFDR MAGJI SFDR MAGISFDR MAGJ SFDR Not available on Smith Chart This measurement along the specified path as shown by SDR n SOP1DBJn TNP n dB where n stage number This simple measurement shows the difference between the 1 dB compression point of the stage and the Total Node Power at the stage output This measurement is extremely useful when trying to optimize each stage dynamic range and determine which stage that will go into compression first See the Stage Output 1 dB Compression Point and Total
26. MTT 39 1991 N 1 p 83 91 M G Slobodianskii A new method of approximate solution of partial differential equations and its application to the theory of elasticity in Russian Prikladnaia Matematika 1 Mekhanika Applied Mathematics and Mechanics v 3 1939 N 1 p 75 82 O A Liskovets The method of lines Review in Russian Differenzial nie Uravnentya v 1 1965 N 12 p 1662 1668 B L Lennartson A network analogue method for computing the TEM characteristics o planar transmission lines IEEE Trans v MTT 20 1972 N 9 p 586 590 U Schulz On the edge condition with the method of lines in planar waveguides Arch Electron Uebertragungstech v 34 1980 p 176 178 U Schulz R Pregla A new technique for the analysis of the dispersion characteristics of planar waveguides and its application to microstrips with tuning septums Radio Science v 16 1981 Nov Dec p 1173 1178 S B Worm R Pregla Hybrid mode analysis of arbitrarily shaped planar microwave structures by the method of lines IEEE Trans v MTT 32 1984 N 2 p 191 196 R Pregla W Pascher The method of lines in Numerical techniques for microwave and millimeter wave passive structures Edited by T Itoh John Willey amp Sons 1989 S B Worm Full wave analysis of discontinuities in planar waveguides by the method of lines using a source approach IEEE Trans v MTT 38 1990 N 10 p 1510 151
27. Measurements are Defined by Paths Since spectrums are propagated to every node in the schematic the user must have some way of indicating signal direction in order to make useful measurements A path is used for just such purpose Basically a path is a node number sequence and is defined by specifying 1 Name or use the default 1 e Path1 2 from node 3 thru nodes optional 4 and to node Given the from node and the to node SPECTRASYS will pick the shortest path between the two node even though several paths may exist If the user would like to look at an alternate path then thru nodes can be specified 82 SPECTRASYS System In the example below if the following two paths existed a 1 3 9 6 8 2 and b 1 5 10 4 7 2 then specifying the path as 1 2 SPECTRASYS would select path a However if the user wanted to specify path b then by simply finding a unique node s then this can could be specified i e 1 10 2 There is no restriction on the number of nodes used to specify a path In some cases several thru nodes may need to be specified to uniquely identify a path BE schi Workspace Getting Started 7 PHASE 1 RFAMP_2 Azo ATTN_2 G 12dB Z0 50 ohm L 298 NMF 3d8 SPLIT2 1 gt T IL 3 0403 dB IS0 30 dB o PH3 0 SPLIT2_2 IL 3 0103 d6 ISO 30 YB PHASE 2 ATTN1 RFAMP_1 A0 O oL 3qB G 12d8 Z0 50 ohm 2 2 NF 3dB
28. RECT Graph RE Smith Chart Sij plots s paramters Commonly Used Operators Operator Description Result Type RECT ZIN1 real imaginary parts Real RE YIN2 real part Real MAGANG ZIN3 Linear magnitude and angle in range of 180 to 180 Real Other Operators MAGI ANG ANG360 IM MAGANG360 Examples Measurement Result in graph Smith chart Result on table optimization or yield ZIN2 RE ZIN2 real part of ZIN2 RECTIZIN Shows real imaginaty parts for all ports MAG YIN1 Linear Magnitude of Y21 Linear Magnitude of YIN1 ZIN RE ZIN1 Shows real imaginary parts of all ports Not available on Smith Chart This voltage gain measurements are complex functions of frequency The frequency range and intervals are as specified in the Linear Simulation dialog box The voltage gain Hi is the ratio of the output voltage V to the input voltage Vi By V Vi Note that due to reflections the gain Ej may not be unity Values Complex matrix versus frequency Simulations Linear 151 Simulation 152 Default Format Table DBANG Graph dB Smith Chart none Commonly Used Operatots Operator Description Result Type DB E12 gain from port 1 to port 2 Real DBANG E21 db and angle in range of 180 to 180 for gain from port 2 to Real 1 Other Operators MAGI ANGI ANG360 RE IM MAGANG360 Examples Measurement Result in graph Smith chart Result on table optimization or yield E12 DB E12 DBA
29. S21 Si2 Values Real value versus frequency Simulations Linear Default Format Table dB Graph dB Smith Chart none Commonly Used Operators Operator Description Result Type DB GMAX maximum available gain in dB Real MAG GMAX magnitude of the maximum available gain Real Examples Measurement Result in graph Smith chart Result on table optimization or yield GMAX DB GMAX DB GMAX MAG GMAX magnitude of the maximum available magnitude of the maximum available gain gain Not available on Smith Chart An available gain input network circle is a locus of source impedances for a given gain below the optimum gain This locus is plotted on a Smith chart and is only available for 2 port networks The center of the circle is the point of maximum gain Circles are displayed for gains of 0 1 2 3 4 5 and 6 dB less than the optimal gain Similarly the power gain output network circle is a locus of load impedances for a given gain below the optimum gain If the stability factor K is less than unity then the 0 dB circle is at GMAX and the inside of this circle is shaded as an unstable region The available power gain Ga and power gain Gp are defined as Measurements Linear G available from network power available from source Gp power deliver to load power input to network Note See the section on S Parameters for a detailed discussion of Gain Circles Values Complex values versus frequency Simul
30. WSP file using internal files namedEMPOWER R1 EMPOWER R2 etc EMPOWER also has the intelligence to detect when two or more ports have the same configuration width position etc and will only run the line analysis once See Microstrip Line for a complete example which examines deembedding EMPOWER External Ports f Mao N Multi VI DO Until now all ports which we have looked at have been single mode ports Single mode ports act just like regular nodes in SUPERSTAR and external components can be added directly to these ports EMPOWER also supports external multimode ports where two EMPorts are close enough together that they are coupled This circuit uses multimode ports with ports 1 2 and 3 being a 3 mode port 4 being a normal single mode port and ports 5 and 6 being a 2 mode port x Multimode ports have the following features e They much more accurately characterize the performance of a network with two or more lines close together on one wall e They cannot be used like normal SUPERSTAR nodes They can only be connected to other multimode ports including multi mod
31. as opposed to the metal areas in EMPOWER Use this for ground planes and other layers which are primarily metal Do not use this for lossy layers See your EMPOWER manual for details Current Direction Specifies which direction the current flows in this layer The default is along X and Y X Only and Y Only can be used to save times on long stretches of uniform lines Z Up Z Down XYZ Up and XYZ Down allow the creation of thick metal going up down to the next level or cover Thick Metal Checking this box forces EMPOWER to model the metal including thickness EMPOWER does this by putting two metal layers close together duplicating the traces on each and connecting them with z directed currents If thick metal is used then Current Direction is ignored EMPOWER Basics Element Z Ports This setting specifies the default direction for automatically created element ports either to the level above or to the level below Generally you should choose the electrically shortest path for this direction Substrate Media Layers All substrate layers from the General Layer Tab ate also shown in the EMPOWER Layer tab These layers are used for substrate and other continuous materials such as absorbers inside the top cover n unlimited number of substrate media layers can be used The following types are available e Physical Desc The layer is lossy These losses are described by Height in units specified in the Dimensions tab
32. frequency of the source is the center frequency plus 2 the bandwidth Power Level This is the average power level of the source in dBm Phase Shift This is the phase shift of the source in degrees Number of Points This is the number of points that represent the source Most of the time 2 points is adequate to represent the source However in cases where the source bandwidth is large and the frequency response of the circuit may affect the bandwidth of the source the user may want to increase the number of the points CW All CW sources have their bandwidth defined to be 1 Hz Furthermore the number of points has been set to 2 points and can not be changed by the user MODULATED A modulated source is currently represented by a uniformly distributed spectrum of constant amplitude This type of spectrum is currently time invariant The user can set the following parameters center frequency bandwidth power level phase shift and number of points USER DEFINED The user defined source is a very powerful feature of SPECTRASYS The user can specify the frequency amplitude and phase in both relative and absolute values Relative parameters are entered into a text file src to specify the desired source in the frequency domain Having relative values specified in a source file is a great advantage because the absolute center frequency power level and phase shift can be tuned in the System Simulation dialog box Absolut
33. or swept are relatively small starting with the previous solution can dramatically speed convergence If the parameters changed are large is sometimes better to start from scratch Certain circuits will always converge faster from scratch than previous solutions FFT Force 1 D FFT The simulator will normally convert frequency spectrums to time waveforms and back using multidimensional FFTs If the frequencies are evenly spaced have a large common factor it may be faster to use a one dimensional FFT On some occasions convergence can also be affected Allow psedo harmonic FFT calculation Artificially changes quasi periodical sional to periodical This allows a increase of calculation speed in multitone analysis An example of this would be a noise analysis with many harmonics Allow non binary FFT Allows the use of FFTs that have powers other that 2 n where n 1 2 3 This allows a decrease the number of FFT points for multitone analysis and will results in calculations speed ups and decreases the needed memory for FFT arrays Krylov Subspace Method 47 Simulation 48 Use Krylov Subspace Method Select this box to use the Krylov technique For large harmonic balance problems this technique can dramatically reduce the amount of memoty and time required to converge Krylov Iterations The largest number of steps the Krylov simulator will attempt before aborting Maximum Number of Iterations The largest number
34. schematic the channel frequency CF is shown in the table Notice that CF is 100 MHz at all nodes before the mixer and 10 MHz after the mixer i e IF frequency 69 Simulation 70 Esch Workspace Getting Started 9 MIXERP 1 RFAMP 1 BEBO s e s s s o o SOE BUM NFS LO 7 dBm 0P108 10 dem ATTN_1 IR 0 dB OP SAT 13 dBm 7 d6 NF 0 dB SIP S 20 dn BPF_BUTTER 1 FLOSS MHz FHIE1 2 MHz IL 0 dB APASS 3 dB DBM CP DBM CHP DB CHR DB CGAIN DB CHFJ o ama saa o o 175 442 93 442 0 471 175 278 83 278 10 635 175 278 83 278 10 635 F2 149 304 Fao 8 16 613 The Channel Frequency is a critical parameter for SPECTRASYS since most of the measurements are based on this parameter If this frequency 1s incorrectly specified then all measurements using this frequency will be incorrect The easiest way to verify the Channel Frequency that SPECTRASYS is using is to look at the Channel Frequency measurement in a Table or a Rectangular Graph Offset Channel 173 276 63 276 10 635 The offset channel is a special measurement that allows specification of a user defined channel and bandwidth relative to the main channel The user can specify the Freq Offset from Channel and Measurement Bandwidth parameters on the Options page of the System Simulation dialog box SPECTRASYS System System Simulation Parameters General Paths Calculate C
35. 15 l lalalel s a s top Front Side Oblique 0 232 0 116 0 Amm To get this snapshot we stopped animation by clicking the Animation camera icon adjusted the view slightly and togeled the background color to white To obtain this view simply press the Oblique button on the toolbar after starting the viewer All other settings are the default e Show XY current density distribution XY X Y Z button e Show Real part of the current density distribution View Menu Switches Value Mode or Value Mode button e Show Absolute values of the current density quantities View Menu Switches Absolute Value Display e Animation is off and time is set to initial View Menu Switches Animation or Animation Camera button e Scale is on View Menu Switches Scale e Solid polygons view View Menu Switches Wireframe or Solid Wite button EMPOWER Viewer and Antenna Patterns Note For printing Toggle Background Color from the File menu was also used to change the background to white To reset the time to zero the animation was turned off and the Real Mag Angle button was clicked three times returning the mode to real but resetting the time The resulting picture in the main viewer window is a 3D plot of the surface current density shown with the grid generat
36. 257 Moll ut rer en etere yen rey 106 Multa ce acetate ER 110 N ING EIP AINEA IE EE 145 NCE P EO A AR 141 New Data Files BAN O N EEA 120 New Data F lest ss 120 Newton RaphsO teer a E a 53 i EE A E TA 141 143 NE NN ta 141 143 Do E T 122 NET enara O A 141 NEA Sonan On 141 143 No li A a 225 Noise Optimal impedance adas 141 INO Gite N A EE 141 NOLE Circles aida 38 141 145 Noise Correlation ooononccconcncconnccancnonananon 122 141 NOLE Daira eae cee ecadd ne eras 122 Noni ot eeseetedencet 1 41 Nonlinear Device hibtaty vienna 125 Nonlinear Device Models osese 119 137 INonlinear JTE Toernee an a E 138 Nonlinear Measurements emmcmccononnncnnnnnnnnnonso 143 Nonlinear MESFET Transistors ccomomomm moo 138 Nonlinear model cies asi eee Soe a 51 Nonlinear VIG S EE Tes dele 138 Non standard metal wind eae 1 Normal deembedded os adds 225 Nota DOS danos 241 Normalized noise resistance ooooocnnnonccinnnnnnnonnns 141 NOT ais 116 Notes aio 143 A O OEE RETR ere Te 119 Numerical Acceleration Procedures 296 O Oblique button aiii 273 Dia ata rc AA er or enon SR REN 70 Ota cosets Bee rece cae E tees teed ces 119 One dimensional PET unidad 43 ODE At S can eaaa Ea 112 Operator descrpions acacia 106 Operators enie 52 110 116 143 145 OPLI REE 50 OptimaladoiHtance ses a 141 Optimal gamma NOSE E 141 Options 141 OHIO dial 8 141 143 145 Optimizing Simulation Performance 53 ORe O AO 116 O
37. 5 in the Model Example below For more information on how to use the Workspace Manager dialogs see the Reference manual Creating A Model From An Existing Schematic To create a model from an existing schematic L Follow the instructions in Creating A Model Without An Existing Schematic above to create a blank model schematic Note You do not have to define model parameters when the Model Properties dialog appears By clicking OK you can continue to create the model However the parameters if any must be defined and a LAYOUT association chosen before the model can be used in a design 2 Copy the existing schematic by selecting the entire schematic and choosing Copy from the Edit menu Paste the copied schematic into the model window by selecting the window and choosing Paste from the Edit menu Copy any equations from the Global Equations window by selecting them and choosing Copy from the Edit menu Right click the model in the Workspace Window See the figure below User Models Workspace Window al ra ET Self Resonant Capacitor User Model Schematic Y Simulations D ata Rename y Outputs Delete This Design Properties _ 3cnematic ail Edit Po Ao del E quatic Ine 6 Choose Edit Model Equations 7 Paste the equations into the model by selecting the Model Equations window and choosing Paste from the Edit menu The model has now been created If you chose to save the worksp
38. 5 lt 4 2 4 gt 14 3 amp 4 4 lt 17 2 2 4 gt 1 3 4 4 lt 17 2 SIN 180 lt 5 Built in Functions Equation Reference This symbol is also referred to as pipes It is normally located on the back slash key using Shift Concatenates values to form vectors an matrices See Arrays in this section Value 64 192 4 75 4 3 5 1 True O False 1 True 0 False 1 True Caution Standard trigonometric functions must have an argument in degrees and inverse standard functions return values in degrees Hyperbolic trigonometric functions use pure numbers not degrees ABS expression absolute value of expression For complex values returns magnitude Alternate form MAG expression ANG expression phase of a complex number returns between 180 and 180 degrees ANG360 expression phase of a complex number returns between 0 and 360 degrees ARCCOS expression inverse cosine cost Range Argument must be between 1 and 1 ARCCOSH expression inverse hyperbolic cosine 107 Simulation 108 ARCSIN expression inverse sine sint Range Argument must be between 1 and il ARCSINH expression inverse hyperbolic sine ARCTAN expression inverse tangent tan Alternate form ATN expression ARCTANH expression inverse hyperbolic tangent BESSELJ0 expression Calculates Bessel function JO of expression COMPLEX real imag returns a complex number real j imag CONTOUR expre
39. Communications Technology and Electronics 1990 N 7 p 71 76 originally published in Radiotekhnika 1 Elektronika v 35 1990 N 2 p 281 286 E V Zakharov S I Safronov D P Tarasov Abelian Groups of finite order in numerical solution of potential theory boundary value problems in Russian GVM amp MF Journal of Computational Mathematics and MathematicalPhysics v 32 1992 N 1 p 40 58 B V Sestroretzkiy V Yu Kustov Yu O Shlepnev Analysis of microwave hybrid integrated circuits by informational multiport network method in Russian Voprosi Radioelektroniki ser OVR 1988 N 12 p 26 42 B V Sestroretzkiy V Yu Kustov Yu O Shlepnev Technique of electromagnetic analysis of microstrip devices using general purpose programs in Russian Voprosi Radioelektroniki ser OVR 1990 N 1 p 3 12 Yu O Shlepnev Method of lines in mathematical modeling of microwave integrated circuit planar elements in Russian Ph D Thesis NEIS Novosibirsk 1990 V Yu Kustov B V Sestroretzkiy Yu O Shlepnev Electromagnetic analysis of planar devices with resistive films and lumped elements Proc of Europ Symp on Numerical Methods in Electromagnetics JEE 93 Toulouse France 17 19 November 1993 p 227 234 V Yu Kustov B V Sestroretzkiy Yu O Shlepnev Three dimensional electromagnetic analysis of planar devices with resistive films and lumped elements Proc of 27th Conference on Ant
40. DCPIM3 n DCPIM3 0 dB where n stage number NOTE This measurement is used by the IIP3 OIP3 and SFDR measurements The Calculate I P3 TOI checkbox must be checked and properly configured in order to make this measurement See the Calculate IIP3 TOT section for information on how to configure these tests See the Desired Channel Power Third Order Intermod Analysis measurement to determine which types of signals are included or ignored in this measurement The only difference between this measurement and the Cascaded Gain CGAIN measurement is that this measurement applies to the IM3 analysis pass only Consequently this will be the same measurement as CGAIN in the Calculate WP3 TOD Manual Mode since a dedicated IM3 analysis is not created and the normal analysis is also the IM3 analysis pass Remember intermod bandwidth is a function of the governing intermod equation For example if the intermod equation is 2F1 F2 then the intermod bandwidth would be 2BW1 BW2 Note Bandwidths never subtract and will always add The channel bandwidth must be set wide enough to include the entire bandwidth of the intermod to achieve the expected results The Automatic Intermod Mode will set the bandwidth appropriately Values Real value numeric Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DB CGAINIM3 cascaded third ord
41. E E E 119 120 139 Letne Bile cz stat aE Gaia a 234 302 A iscsi E E ARER 107 TIN enea EE anglican teers 110 ENMIES WS P tann na aa 2AA Esad Pull COMOULS siesta id 167 O A Rna 143 145 E Oe 107 Losicl Operator ardid 116 A A 236 ESA AA 217 A T EE E 257 Los vineta ii 297 Lumped Elements sses 214 225 261 288 M IVI NC casas tea atat 107 143 MACAN Gasalla 141 143 MAGANG GO it 143 Masnehe Wal isaac a Mide de eno od E Ze Maa CEU C ao lessctvccebsratacents 119 123 MACE aia e a 110 MALRI A itie EN 107 A EE E ea E N Meateeaniieals 107 Maximum Amplitude Step unitat 53 Maximum Mixing Ordet 53 Maximum stable Panal 36 Maxwells Equation 287 Measurement Band width alone 68 Measurement Wizard c ooconoccccononccnnnninnnanos 115 141 Measurements 32 41 52 107 112 141 143 145 146 279 Measuring NS Ne e Oo E 32 IVICA SUIT a e R E E R 32 MESE Sii 138 S TE e EE O tees 217233299 MEA tia 273 Metallizadon lancia PAN NS Y Method oal 290 MICEOST P alias 217 220236 A A ae tase states Rete ta sce tache cutee 107 Md e de 234 A A A 26 NM EEP eaS 301 304 Mode Setup DOK ansaa a 250 Moda da 119 125 127 134 Model Edit ts 135 Model Properties crimson tias 133 MISS MIE E S A stat aerate 36 TION EEE E tae A AE EEA T E 110 Multi dimensional aa 112 Multidimensional FFTs oooccccononcconnoconnnonnnonnnoos 43 Malino 6 Lesser reme mar oi etre Ra eT 219 261 Moultism0d nasa 245 249 250 257 277 Multimode Mes
42. E a Simulations D ata IB 10e C IB 8e 6 MAGTlic pu gt Ib Sweep IDC E Vo Sweep NA a ra Outputs hen BA DC Curves po e 2 Equations E a Substrates C IB 2e 6 E hu EN Untitled 1 pu B Optimizations C IB 6e 6 C B 4e 6 aj e mactic Error 0 DC Analysis Biasing the Transistor This walkthrough continues from the DC Analysis Device Verification walkthrough The next step is to properly bias the transistor For this example we arbitrarily chose a collector voltage of 2 5 volts and an Ic of 10ma 1 Right click on Designs Models and select Add a Schematic Name the schematic DC Bias and click OK For the Schematic Properties dialog box select defaults by clicking O K 2 Inthe Workspace window double click on the DC1 simulation and click the Annotate box for the DC Bias schematic 3 Goto the DC Curves schematic and select Select All from the Edit menu to select all components Select Copy from the Edit menu 4 Goto the DC Bias schematic and select Paste from the Edit menu 5 Double click on VC and change the DC Voltage to 5 Click OK While VC is still highlighted hold the Alt key down to disable Keep Connect Use the Up arrow key to move VC up six spaces to make room for a resistor 6 Delete current source IB and related ground 7 Press the R key on the keyboard and place resistor R1 between VC and the ammeter Make R1 s resistance 7100 Pre
43. Er relative dielectric constant Ur relative permittivity constant normally 1 and Tand Loss Tangent e SCHEMAX substrates Choosing a SCHEMAX substrate causes the cover to get the height Er Ur and Tand parameters from that substrate definition We recommend using this setting whenever possible so that parameters do not need to be duplicated in SCHEMAX and LAYOUT Caution For true stripline triplate be sure to check the Use 1 2 Height checkbox if you are using a substrate from SCHEMAX This forces EMPOWER to use 1 2 of the SCHEMAX substrate height for each substrate above and below so that the total height for both media layers is correct In addition to the metalization and substrate layers viaholes and other z directed currents can be used These currents can go from the metalization layer through one media air layer to either the top or bottom walls Besides conductive materials ports are placed on the metal layers and in z directed positions All conductive surfaces and ports must be on a grid This grid is composed of regular rectangular cells An example of mapping a microstrip bend to the grid is shown below The left half of the figure shows the circuit as it appears in LAYOUT The right half of the circuit shows a part of the EMPOWER listing file Each of the plus signs in the listing file represents an intersection of two grid lines as shown on the layout Lines connecting plus signs represent metal
44. GU1 Circles GU2 Circles Note On a graph or in optimization measurements which use DBANG by default show the dB part measurements which use MAGANG show the magnitude and measurements which use RECT show the real part Note For port numbers greater that 9 a comma is used to separate port numbers For example on a 12 port device some of the S Parameters would be specified as follows 1 11 12 2 12 11 12 2 Measurements Overview Tip All available measurements and their operators for a given circuit or sub circuit with their appropriate syntax are shown in the measurement wizard To bring up the measurement wizard select measurement wizard from the graph properties dialog box Meas Description Default Operator Shown on Smith Chart V node Peak Voltage at node node is the node number or MAG the name of the node as specified by the voltage test point designator name Iprobe Peak Current through probe probe is the current MAG probe designator name Pport RMS Power delivered at port port is the port DBM number Measurements are combined with operators to change the data format The general format for combining operators with measurements is operator measurement or operator measurement where operator is one of the operators listed in the table below and measurement is one of the measurements listed in the table in the previous section Also available is the operator which may be combined with any oth
45. Inductor 2 WSP e Box Modes WSP e Film Atten WSP e Edge Coupler WSP e Dual Mode WSP e 8 Way WSP e Edge Coupled WSP e Coupled Stepped Z WSP e Tuned Bandpass WSP e Patch Antenna Impedance WSP The required RAM specified in the Examples manual is the value estimated by EMPOWER They are approximate and are determined by algorithm rather than a test of memory used The execution times are for a 266 MHz Pentium II with 256Mbytes of RAM operating under Windows 98 In most cases execution time is for the discontinuity mode A board layout can be created one of two ways e By starting without a schematic e By starting from an existing schematic The first method starts in the GENESYS Environment by creating a layout without an associated schematic The layout is created by drawing lines and placing footprints in the LAYOUT editor The second method begins in with a schematic and creates a board layout based on the schematic objects This method is normally used when a linear simulation using GENESYS has been performed on a schematic and an EMPOWER simulation is desired or when any lumped elements are needed in the EMPOWER Simulation In addition to the schematic objects any desired LAYOUT objects can be added to the board before simulation For example linear simulation would normally not include EMPOWER Operation ground pours power supply rails and lumped element pads However these are included in the EMPOWER run allowing i
46. Node Power measurements to determine which types of signals are included or ignored in this measurement Values Real value numeric Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operatots Operator Description Result Type DBISDR stage dynamic range in dB Real MAGJ SDR numeric value of the stage dynamic range Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DBI SDR DB SDR DBI SDR MAGI SDR MAGI SDR MAGJSDR Not available on Smith Chart This measurement is the noise figure of each individual stage along the specified path as shown by SNF n CNP n CNP n 1 GAIN n dB where n stage number Passive Stages 187 Simulation 188 OR SNF n Noise Figure of the Active Stage dB where n stage number Amplifier and Mixer Stages The Stage Noise Figure is the noise figure of each individual stage For all passive devices this noise figure is based on the channel power and stage gain However for amplifier and mixer stages this noise figure will be the noise figure entered in the parameters for these devices This measurement is used to aid the user in determining the added noise by each stage in the cascade See the Gain and Channel Noise Power measurements to determine which types of sionals are included or ignored in this measurement Values Real value numeric Simulations SPEC
47. Numbers represent port locations Notice that the ports map onto the grid in place of metal so the ports go between the end of the line and ground the wall so each port has a ground reference as would be expected 221 Simulation IE CEES ld tthe eee eee eae Ib stb eee eee eet 4 let h ee ee eee eats El 1 ee4 e 4e5544 4 LO ebb ee ee EE EH Ml E Ft Et 4 E A a a a a Ft 4 HSRC 4 A eine ae ra E ttt tet t t ttt tt 4 sete ee bee EE BL AAA tet i sa e da ade oe eee SS al fee ee ee tee EMPOWER will move all surfaces to the nearest grid cell before analyzing a circuit EMPOWER maps the structure onto the borders of the cell not onto the space inside the cell A slightly more complex example which does not exactly fit the grid is shown below There are three important things to notice in this figure 1 The stub line going up is about 2 1 2 cells wide but is approximated by EMPOWER as being 2 cells wide 2 The chamfered corner is approximated by a stairstep 3 The viahole near the end of the stub is represented by an asterisk in the listing 012345678589012345 15 141 hail oe a aa i 2E t A CESTNE A 111 ae ttt tte tt 101 e t io 4 3 ee ee ae tt tt A Bla rec ee 5 ttt EER 4l 4 44 TED 4 4 31 ttt EEF 4 z 4 4 TER 4 1i ttt ee 4 4 4 l
48. Passive Mixer found on the System toolbar 2 Looking at the output spectrum you will see the RF and LO sneaking through You will also see intermods which were generated 3 Add another graph called Input Spectrum Add measurement P1 from System1 Composite You will see that the LO has come back towards the input and is being sent backwards along the RF chain You will also see that the second harmonic generated at the amplifier comes back towards the input Seeing these Sneak paths is one of the more powerful features of SPECTRASYS Note The mixer is orange because the mixer has a local error after a simulation is performed The local error can be viewed by right clicking on the mixer and selecting Show Local Errors This error shows that the mixer is being overdriven Note You must have Show Contributors Signals checked to see the sneak paths below noise Note The walkthrough at this point is saved in Examples SPECTRASYS Walkthrough 6 Mixer WSP 26 Walkthrough SPECTRASYS SPECTRASYS can easily handle many signals simultaneously We will add mote signals to the input port to see the impact on the system 1 Double click on the system simulation 2 Uncheck the Enable checkbox on the first source line to disable the 100 MHz CW signal coming into Port 1 3 Click on the Add button on the third empty source line 4 Make the source box look like System Source Parameters xX Source Name Inpu
49. RUSTED 257 So pe tucan merece Terre gare See ZY Piercad Or ell he GLO Ha Rae er ere ni AS it ae AN 238 Thick Metals adas 239 OSM in es ote aden east etna aes 241 Placino E sternal POIS eri ts 241 EMERG OPIO aaea E na 241 DEMAS A 243 IT INOS otitis 245 Generallacd o Paramotor usa 247 A IE PEIN AETA IA ET E AAE EE 249 DC a 249 Spiral Tae tn mae coda E 250 WES SSS N O E E OO 257 Portu Der 257 OMS Si A A SPS TES ET SONG ONG TEE Ur 259 Plans Tater ial POr aie an a oesescattist ch teuseibed uaa tapicl aaah usb sauce ae lathons 259 Manually Addie Lum ped Plementsdna ori 260 Attomatte Porta connect 260 Planar X and Ya Directed POS AN 261 REOM Gl eR MTNA Ere isa 263 vil Table Of Contents viii OVEN O Wraae eaa ie e e a ee eas 265 LOS O 265 Farsbiela Radiaton Pattern VI Wet st pdas 270 EA E tata 273 MuliVMode Viewer Data il lios 207 VWaiblole Viewer Exa a 278 NASW O eeuebinba tome meranabiles 219 SONA A AAA AA AAA AA tadleeanpainonnGs 281 IVCIN IEW a EAN E E eevee eta E ene ite heave tends 283 Homogeneous Rectanoulat Cavity urias nenna A AA 283 Hohner Order Bor Modeion e A a T E al da neat 284 Parral electro Loria dada 285 Sional Melisa did das 285 TOP COVE arena a tds 285 GAL AO Deba cla at eed ce E E 285 Ny Cy nnan sacs a ocean e are 287 Historical aC Or OU ING enor a A 288 Pro blenr Forni ON AA AS 288 Method of LINES ati E Ea 290 Mappias onie G ienna a Eaa eaa 291 ECS E Lao OPONE O OO PEO ES E N EE 293 tormnato nal NA
50. S parameter data given earlier includes noise data This data is comprised of four numbers for each frequency These numbers are NFopt dB the optimum noise figure when correctly terminated Gopt magnitude and angle the terminating impedance at the device input which acheives NFopt and Rn Zo a sensitivity factor which effects the radius of the noise circles Noise circles plotted by SUPERSTAR for the AT10135 at 2500 MHz are given below Circles of increasing radius plotted by GENESYS represent noise figure degredations of 0 25 0 5 1 1 5 2 2 5 3 and 6 dB In this case direct termination of the device with a 50 ohm source results in a degredation of the noise figure of 1 dB The arc orthogonal to the circles is the locus of Gopt versus frequency Linear Simulation Response SPARAM 50 y E E AN Fy DB NCI 2000 4000 3 09804 8 17871 3 09804 8 17871 Smith Chart In 1939 Philip H Smith published an article describing a circular chart useful for graphing and solving problems associated with transmission systems 36 Although the characteristics of transmission systems are defined by simple equations prior to the advent of scientific calculators and computers evaluation of these equations was best accomplished using graphical techniques The Smith chart gained wide acceptance during the development of the microwave industry It has been applied to the solution of a wide variety of transmission system problems man
51. The data is given in linear polar format magnitude amp angle The frequencies are in megahertz The data follows after the format specifier A typical line for this two port file is 500 64 23 12 5 98 03 70 8 37 In this case 500 is the frequency in megahertz The magnitudes of 11 S21 S12 and S22 are 64 12 5 03 and 8 respectively The phases are 23 98 70 and 37 degrees respectively Alternatively Y parameter data may be used The format specifier could be GHZ YRIR1 This would indicate rectangular unnormalized Y parameter data with frequencies in GHz A typical line is 30 0 3E 4 9E 3 8E 3 2E 5 0 1E 4 1E 3 In this case the frequency in gigahertz is 30 The real values of Y11 Y21 Y12 and Y22 are 0 9E 3 2E 5 and 1E 4 mhos respectively The imaginary values are 3E 4 8E 3 0 and 1E 3 mhos respectively A sample S parameter data file is shown below The only portion of the file required for GENESYS is the segment in the middle with frequencies and S parameter data Lines in the data file beginning with are comments and are ignored The noise data at the end of the file is used for noise figure analysis Noise is discussed in a later section AT41435 S AND NOISE PARAMETERS Vce 8V Ic 10mA LAST UPDATED 06 1 89 GHZ SMA R 50 IFREQ S11 S21 S12 22 0 1 80 32 24 99 157 011 82 93 12 0 5 50 110 1 2 30 108 033 52 61 28 1 0 40 152 6 73 85 049 56 51 30 1 5 38 176 4 63 71 063
52. Use Internal file for EMPOWER but can also be used in the SMTLP and MMTLP models in GENESYS EMPOWER must perform a separate line analysis for all external ports If no filename is specified by the user then the results from the line analysis are stored in Ln files These files also store all information about the box and port and are intelligent They are only recalculated if necessary and even then only at frequencies necessary Even if the circuit changes they are only recalculated if the change affects the line analysis Notes When these files are numbered modally related groups of ports are counted as one Also if two ports are identical then only the first one will create a Ln file Written by EMPOWER Type Text Can be safely edited Yes Average size 50K to 200K but may be larger Use Gives all calculated data and grid mapping from EMPOWER in human readable form This file is overwritten whenever EMPOWER is run It should be carefully checked whenever a new circuit is analyzed especially if that circuit was described manually from a text TPL file The following sections describe the contents of a listing file Note Some of the information described below is only output if Output additional info in listing file is checked or La is specified QCHK SECTION This section allows you check the quality of the solution Entries include Min media wavelength to mesh size ratios should be at least 20 Thinning out th
53. YP21 Linear Magnitude of YP21 YP Shows real imaginaty parts of all Y Parameters Not available on Smith Chart This Z parameter or impedance parameter measurements are complex functions of frequency The frequency range and intervals are as specified in the Linear Simulation dialog box The Z parameters for an n port network are of the form ZP for i j equal 1 2 n For a two port network the equations relating the input voltage V1 and current l to the output voltage V2 and current 12 are V1 ZP11 l ZPi2 Iz V2 ZPa lh ZPz z Values Complex matrix versus frequency Simulations Linear Default Format Table RECT Graph RE Smith Chart none Commonly Used Operators 149 Simulation 150 Operator Description Result Type RECT ZP11 real imaginaty parts Real RE ZP22 real part Real MAGANG ZP21 Linear magnitude and angle in range of 180 to 180 Real Other Operators MAGI ANGI ANG360 IM MAGANG360 Examples Measurement Result in graph Smith chart Result on table optimization or yield ZP22 RE ZP22 real part of ZP22 RECT ZP Shows real imaginary parts of all Z Parameters MAG ZP21 Linear Magnitude of ZP21 Linear Magnitude of ZP21 ZV Shows real imaginary parts of all Z Parameters Not available on Smith Chart The VSWR measurement is a real function of frequency The measurements are made looking into the network from the port with other network terminations i
54. and can be one of the most challenging components to characterize and make behave properly under all system conditions SPECTRASYS will aid the user in understanding the output spectrum of the mixer and all of its non ideal characteristics such as isolation Three types of mixers are available in SPECTRASYS they are Passive Active and Intermod Table Mixer The only difference between the Passive and Active mixer is respectively the Conversion Loss and Conversion Gain See RF Mixer and Intermod Table Mixer in the Element Manual for more specific information about each mixer Passive and Active Mixer Model The mixer can be thought of as two amplifiers one on the RF port and the other on the IF port both facing an ideal frequency translation or mixer as shown in the following figure IF 2 LO to RF Isolation LO to IF Isolation LOS The isolation parameters appear port to port and bypass the effects of the amplifiers and ideal mixer Any signal appearing on any of these ports will be propagated to all of the other ports through the respective isolation Obviously no frequency translation is taking place during the isolation calculations Signal Spectrum Arriving at the LO Port All spectrums arriving al the LO port will be propagated without a frequency translation to the RF and IF ports with their respective isolations However only the highest power level LO signal is currently being used to create the mixed
55. appropriate for a wide range of microwave and mm wave devices such as planar filters dividers combiners matching circuits phase shifters attenuators diplexers amplifiers as well as their components The method of partial discretization later called the method of lines MoL is as old as partial differential equations and the finite difference approach to their solution Traces of it can be found in the 18th century works of J L Lagrange Its first conscious usage for the numerical solution of elliptical problems could be attributed to M G Slobodiansku 1939 An almost complete reference on the MoL development and applications in the period from the beginning up to sixties are given in Liskovets paper 1965 The network analogue method of B L Lennartson 1972 is probably the first technical application of the MoL to the static numerical analysis of planar multiconductor lines It was not quite straightforward when it was published and the actual exploration of the method for microwave integrated circuit structures began in the early eighties in works of German scientists H Diestel R Pregla U Schulz S B Worm and others Pregla Pascher 1989 The EMPOWER algorithms can be also classified as MoL because of its semi discrete nature Originally the network impedance analogue method Kron 1944 Sestroretzkiy 1977 and a grid spectral representation inside homogeneous layers were used to analyze the layered three dimensional str
56. are the spectrums going both directions Signal noise from input thermal noise only from output at node two To see only the spectrum going one direction you can plot the spectrum along a path Note that you can see all of the pieces that combine to make this composite signal and can use markers and fly over help to determine exactly where the signals came from To do this 18 Double click on System1 in the workspace window 19 Click on the Composite Spectrum Tab 20 Check Signals and Intermods and Harmonics 21 Select the radio button Individual Components 22 Press OK You will see a graph like the one below Placing a marker on the peak will show the source of the signal and moving the cursor over the marker will give more details In this case the green signal started at the input INP_PAC1 went out the port and through the listed nodes and elements 20 Walkthrough SPECTRASYS Note You can zoom in easily on the graph using your mouse wheel or using the zoom buttons on the toolbar BE Output Spectrum Workspace 2 Add Simulation 1 100 MHz 100 a 115 205 Total from Port2 20 4 i b 55 992 Total from R2 c 55 992 S1 11 5 3 4 2 40 4 tc DBM P2 5 100 MHz 55 992 604 A INP_PAC1 Port1 A4TTN_1 I50_1 R1 R2 200 UR T t j l 0 50 100 150 200 250 300 350 400 450 500 Frequency MHz e DBM P2
57. bandwidth follows the intermod equation that determines the frequency except for the fact that bandwidth cannot be subtracted For example if the third order intermod equation is Fim3 F1 2 F2 then the equation for the resulting bandwidth would be BWim3 BW1 2 BW2 If BW1 30 kHz and BW 1 MHz then the resulting bandwidth would be 2 03 MHz The user needs to make sure that the Channel Measurement Bandwidth is set wide enough to integrate all of this energy Calculate Intermods and Harmonics A checkbox named Calculate Intermods and Harmonics located on the Calculate page of the System Simulation dialog box can be used to disable enable all calculation of all intermods and harmonics Simulation speed will be increased for large number of carriers and nonlinear stages if intermods and harmonics are being calculated The user can disable this option to increase the simulation speed if intermod and harmonic calculations are unimportant Cascaded Intermod Equations Cascaded intermod equations are NOT used by SPECTRASYS There are two serious drawbacks using the cascaded equations First the equations assume that the interfering input signals are never attenuated through the cascade of stages This may be fine for in band intermod measurements but will be completely inaccurate for out of band intermod measurements such as IIP3 for a receiver where the out of band interferers are attenuated through the IF filter Continuing the
58. before being passed into your model They are the ones shown on the units combo box NL nonlinear units are a convenience when using nonlinear devices which are generally specified using fundamental units Layout Association PAD bal OF Cancel Parameter These entries are the parameter variables that can be used in model equations When referring to these parameters in a model they must appear precisely as entered here with the exception of upper lower case they ate not case sensitive Description Human readable description of each parameter This description is shown in SCHEMAX part dialog boxes Units Describes what type of units that each parameter uses 133 Simulation Layout Association Defines which association table entry to use for this model This defines the default footprint which will be used for this model when it is on a layout Symbol Allows the user to select the schematic symbol associated with the model Using A Model In SCHEMAX You can replace any element with a user defined model in SCHEMAX To do this 1 Double click on an existing symbol that you have already drawn to change its model 2 Press the Model button 3 Choose the model to use from the combo box An example is shown below Change Model EZ Category c program files genesys version 7 0 examples SELF_RESONANT wsp y New Model AMATER eda Cancel 4 Press OK 5 Enter the parameters required for t
59. being used for the OCP Offset Channel Power measurement It s always a good idea to add this frequency measurement to a table so the user knows that all parameters have been correctly specified Furthermore when a mixer is encountered the user will know exactly which frequency is being used for the offset channel power measurement The OCP measurement can be added to a level diagram or a table to show the power of the phase noise as it travels along the specified path Coherency Coherency Coherent signals have similar direction amplitude and phase and originate from a common source If two coherent signals have the same amplitude and phase when added together will cause a power increase by 3 dB Furthermore if the same two signals had the same amplitude but where exactly 180 degrees out of phase they would cancel each other out Whereas two non coherent signals of the same amplitude when added together will only produce a 1 5 dB increase in output power and two identical non coherent signals will not cancel each other out 71 Simulation SPECTRASYS deals with coherent and non coherent signals and follows these rules 1 Each source is non coherent with any other source For example the following two sources on input Port 1 are considered non coherent Sourcel CW 100 MHz 50 dBm 0 Deg Source2 CW 100 MHz 50 dBm 0 Deg even though they both have the same frequency amplitude and phase 2 Once a source divide
60. box is of the form 223b5c741113f where e and f ate either zero or one and a b c and d are arbitrary integers In other words a circuit with a box 512 cells by 512 cells 28 by 28 will analyze much faster than a circuit with a box 509 cells by 509 cells 509 is prime Making one side a preferred number will help so a box 509 x 512 cells is better than one 509 x 509 cells Note that only the time while EMPOWER is working on the Fourier Transform is affected and this is normally only substantial with boxes 100x100 or larger If you see a status with FFT in the message for a long time check to see that the box width and height are a preferred number of cells across Preferred numbers which fit the form given above 10000 and below are 12345678910 11 12 13 14 15 16 18 20 21 22 24 25 26 27 28 30 32 33 35 36 39 40 42 44 45 48 49 50 52 54 55 56 60 63 64 65 66 70 72 75 77 78 80 81 84 88 90 91 96 98 99 100 104 105 108 110 112 117 120 125 126 128 130 132 135 140 143 144 147 150 154 156 160 162 165 168 175 176 180 182 189 192 195 196 198 200 208 210 216 220 224 225 231 234 240 243 245 250 252 256 260 264 270 273 275 280 286 288 294 297 300 308 312 315 320 324 325 330 336 343 350 351 352 360 364 375 378 384 385 390 392 396 400 405 416 420 429 432 440 441 448 450 455 462 468 480 486 490 495 500 504 512 520 525 528 539 540 546 550 560 567 572 576 585 588 594 600 616 624 625 630 637 640 648 650 660 672 675 686 693 700 702 704 715 720 728 729 735 750 756 76
61. by a manufacturer or a nonlinear model requires HARBEC If a nonlinear model is used GENESYS automatically runs a DC analysis to determine the circuit operating point linearizes the nonlinear circuit around the operating point and uses that linear model in the analysis To add a linear simulation 1 Right click the Simulation Data node on the Workspace Window 2 Select Add Linear Simulation 3 Complete the Linear Simulation Properties dialog 4 Add a graph or other output and a measurement to see the results See also Measurements later in this manual Outputs Overview User s Guide To open double click or create a Linear Simulation Linear Simulation Properties Frequency Range Start Frequency MHz 2000 Stop Frequency MHz 3000 Type OF Sweep K Cancel Help ibe Factory Defaults Linear Number of Points 101 Log Points Decade 101 O Linear Step Size MHz 10 List of Frequencies MHz Temperature 27 0 ae 31 Simulation 32 Frequency Range e Start Frequency The lower bound minimum frequency of the linear simulation e Stop Frequency The upper bound maximum frequency of the linear simulation Type of Sweep e Linear Number of Points Allows specification of start and stop frequencies and number of points e Log Points Decade Allows specification of start and stop frequencies and number of points e Linear Step Size Allow
62. cascaded intermod analysis past the point where the interfering signals are attenuated will result in erroneous results Secondly with cascaded intermod equations it is very difficult to identify weak links in a cascaded chain In SPECTRASYS interfering signals are created and set to the frequency of the actual interferers These interferers need not be limited to two tones and they will be appropriately attenuated by the frequency response of each stage Consequently intermod SPECTRASYS System measurements will be accurate no matter whether the interferers are in band or out of band Intermod Tests Calculate IIP3 TOI This function needs to be enabled in order for intermod measurements can be correctly calculated Cascaded intermod equations are NOT used by SPECTRASYS There are two serious drawbacks using the cascaded intermod equations See the section Cascaded Intermod Equations for additional information Also see the Calculate Intermods and Harmonics section for additional intermod information This function can be enabled by checking the Calculate IIP3 TOD checkbox located on the Calculate page of the System Simulation dialog box When the Automatic 2 Tone intermod mode is enabled SPECTRASYS will create an entire new analysis using only the 3 signals needed by the automatic 2 tone test Only the intermods created from these 3 sources will be used by the intermod measurements This analysis pass is sometimes r
63. characteristic impedances while the internal ports are terminated by 1 Ohm if another termination is not defined by the option NI lt n gt e The instantaneous power of the incident wave is 1 Watt and time average power is 1 2 Watt e Surface current density functions are used for the signal or metal layer and integral currents are used for viaholes and z directed inputs 281 EMPOWER Box Modes A fully enclosed rectangular box acts as a cavity resonator At frequencies near each resonance mode significant coupling exists between the desired signal metalization and the cavity Because this coupling is reciprocal coupling occurs between segments of the signal metalization This is nearly certain to perturb the circuit responses as the operating frequency approaches or exceeds the first resonant frequency of the cavity While EMPOWER inherently predicts these effects they may have a significant destructive effect on the performance of your designs Box modes are clearly illustrated in this example In the formulation which follows we use definitions from the section on Geometry The height of the box in the z direction is h the length of the box in the x direction is a and the width of the box in the y direction is b The resonant wave number for a rectangular cavity 1s 2 ae Y mn nt T Ries NE a ers T E a Ay b MKS units and the resonant frequency when homogeneously filled with material with a relative dielectric constan
64. corresponding to the actual current values If a via hole surface shape is known using the current in Amperes it is possible to estimate a current density on the via hole surface It is obvious from the picture that the current density is higher on the via hole side that is closer to the microstrip line segment empower Viewer V6 5 LOL File View xY a Mag sold Freq GHa 2 ol l l eljeja 4 Top Front Side Oblique 2 514 1 257 0 Amm empower Yiewer V6 5 Jol x File View Z 8 Mag Solid Freq GHa 2 l lalolels a s top Front Side Oblique 0 023 HHEH 0 011 HMHH H 0A Viewer Theory The EMPOWER viewer is a program designed to read to process and to visualize the current distribution data created by EMPOWER To obtain a current distribution inside a structure the excitation condition must be defined This mirrors a real measurement where there are incident and reflected waves The viewer depicts the case with one incident w
65. degrees of phase corresponds to a one wavelength delay period The difference of the current phases at the input and output again confirms a 90 degrees line segment empower Viewer V6 5 LOL File View x a Ang wie Freq GHz 15 1a a e 4 4 Top Front Side Oblique The line segment example was prepared at two frequency points All graphs and explanations given here used the first frequency point 15 GHz The second point is 30 GHz and the corresponding segment length is a half of the wavelength You may display results at 30 GHz by clicking the button and then choosing the views of your choice This example illustrates the eigenwave multi mode excitation capabilities of EMPOWER A three conductor coupled microstrip line segment from Farr Chan Mittra 1986 is described in the schematic file LNMIT3 WSP Three microstrips are 1 mm wide and 0 2 mm apart They are on a 1 mm substrate with relative permitivity of 10 The segment is 8 mm long The structure has three modally coupled inputs at opposite segment sides We expect at least three propagating modes Load the example in GENESYS The listing file Right Click on the EMPOWER simulation in the Workspace Window and select Show Listing File gives information about the propagating waves The first eigenmode is an even mode with integral current distribution pattern the second eigenmode is odd pattern 0 and the third one is again even pattern To ex
66. frequency With this 3 element lowpass prototype the attenuation 30 channels from the center will be about 117 dBc Gaussian to 150 dBc 200 Chan BW Data will be ignored that is farther than 200 channels away from the center frequency With this 3 element lowpass prototype the attenuation 30 channels from the center will be about 150 dBc Randomize Noise This checkbox enables random noise When enabled random noise will be added around the resulting analyzer sweep In this way the output will be more representative of a typical spectrum analyzer at the expense of additional computation time Add Analyzer Noise This checkbox enables the analyzer noise floor All spectrum analyzers have a limited dynamic range They are typically limited on the upper end by intermods and spurious performance at the 63 Simulation 64 internal mixer output On the lower end they ate limited by the noise of the analyzer This noise is a function of the internal architecture of the specific spectrum analyzer and the internal RF attenuator The user has the ability to enter a noise floor for the analyzer to more accurately represent the data that will be measured in the lab Analyzer Noise Floor When the Add Analyzer Noise is checked analyzer noise will be added to the resulting analyzer trace This parameter will also aid the user in correlating the simulation results with what would actually be measured on a spectrum analyzer Limi
67. frequently after dominant mode resonance It is possible to minimize perturbations in narrowband applications by operating between resonant frequencies However the above analysis assumes a pure homogeneous EMPOWER Box Modes rectangular cavity and dielectric Partial dielectric loading and signal metal within the cavity will influence the frequency A more conservative and safer approach is to enclose the circuit in a box with the dominant resonant mode higher than the highest frequency of interest If the cavity is not homogeneous but instead is partially filled with a dielectric and the remainder of the cavity is filled with air then the dominant mode resonant frequency is reduced and may be approximated using a filling factor Johnson 1987 Assuming the substrate is mounted on the floor of the cavity the resonant frequency of a partially filled rectangular cavity frartial 18 e 1 pp partial or 127 Y P where t is the thickness of the substrate and h is the height of the cavity without a substrate For example J101 for the 2x4 inch box is reduced from 3299MHz to 3133MHz with t 62mils and e 4 8 This expression is approximate because the electric field lines are not parallel to the z axis and a component of these lines terminate on the side walls This mode is referred to as a quasi TEM 191 mode Relatively sparse signal metal has little effect on the resonant frequency Larger metal segments particularly when groun
68. iS 145 Usine Nog Default Simulation Dat 145 Using Equation Results POSt prOcessin dnd id 146 Satin ete aa 147 atari AAA Aia 148 VACA SA di 148 O AOS 149 Voltase optandi Wave Ration OW RR sanar ia did 150 Input Impedance Admittance LINO VINE 151 MOLA diia 151 Noise Measure MAS dede 152 Noise Figure NF Minimum Noise Figure NFMIN cooocococonccnnnnnnnnnnnnanocanacanncnononanoranananans 153 Constant Noise Circles NOD alista 153 Noise Correlation Matti Parameters psico 154 Simultaneous Match Gamma at POr 1 ON 155 Simultaneous Match Admittance Impedance at Port i ZMi YMD ou eeeeeeseteteeeeeeeees 155 Maximum Ayalabl Gan GMA cea 156 Avalable Galo Power Gain C rele GA GP hieer a 156 Unilateral Gan Circles at Porti GUL GU 137 Stability Factor K Stability Measure Di R S EA 158 Input OQueput Pline Stability Cercles SBI SBA E 158 Optimal Ganna tor Nose GOP T eraa a a 159 Optimal Admittance Impedance for Noise YOPT LOPD rosca 159 Ettectve Noise Taput Temperaire NET ien n a N T 160 Normalized Noe Resistance iaa 160 Reference Impedance ZPORR Tronco E 161 Table Of Contents PO OW EPO ati iio 163 Probe Current prODE e 163 Node Voltage VO de a ase Sastre naa a e E E E OE paca eieeeedeaees 164 Retcrence linped ance APO RV il eae ace aeaes 164 Larse Si tial Sc PALACE ruta O 165 Load Ea ell Grey ob noes gc steer errr rer ere cree nomen eee errr tracert crete ore ere rece terres eae crete te 167 Tocteate a new file us
69. lumped elements are not included in the EMPOWER data there are generally many fewer resonances and the data interpolates much more accurately In this case you may want to only use 2 or 3 points in the electromagnetic analysis while showing the results of the entire network with 100 points or more specified in the Co Simulation Sweep in the EMPOWER Options Dialog box For a complete example which takes advantage of this property see the Narrowband Interdigital example 263 EMPOWER Viewer and Antenna Patterns This section describes how to launch the EMPOWER viewer program and how to use it to visualize and interpret currents or voltages generated by EMPOWER It also describes the viewer interface The EMPOWER viewer helps you visualize current distribution and densities in a board layout It processes current density magnitude and angle and plots them as two or three dimensional static or dynamic graphs These plots provide insight into circuit behavior and often suggest modifications which improve the performance Most electromagnetic simulators include visualization tools The EMPOWER viewer has distinct advantages such as three dimensional graphs true animation capabilities and precise information about current phase The full potential of the EMPOWER viewer is realized with practice sO we encourage you to investigate your circuits with the viewer and reflect on the results you observe The viewer is started by selecting Run View
70. microstrip there are three media layers two air and one substrate For buried microstrip there are also three media layers two substrate and one air 217 Simulation 218 BOTTOM _ Y SIDEWALLS The dialogs below show two typical EMPOWER Layer Tab setups one for microstrip and one for stripline triplate The EMPOWER Layer Tab must be carefully checked when a new problem is created as it is probably the most likely source of errors when setting up an EMPOWER run Create New Layout cc Se SEE TopCover Sub Teton 07 Air Above M See DEA R ES REA OOE M D fuetefon ago o d pass Norme E s re st 22 fonos fr tm po op pj O To o po pp _ Sub Teflon 07 d A 0055 EMPOWER Basics Create New Layout X General Associations General Layer EMPOWER Layers Fonts AA A Thickness Sigma Value or File bee Cover Sub Teflon Sub Teflon 55 2 55 la 0004 TOP METAL Sa Sub Teflon 4 2 55 10 0004 BOT METAL Sub Teflon Cancel Apply The EMPOWER Layer Tab consists of the following main entries Top Cover and Bottom Cover Describes the top and bottom covers ground planes of the circuit e Lossless The cover is ideal metal e Physical Desc The cover is lossy These losses are described by Rho resistivity relative to copper Thickness and Surface Roughnes
71. n Virtual Tone Power n Delta n 2 dBm where n stage number Virtual Tone Power n TCP 0 CGAINIM3 n Delta n Virtual Tone Powet n TIM3P n Delta is the difference in dB between the Total Third Order Intermod Power in the main channel and the first adjacent signal tone that created it for the current stage This first adjacent signal tone channel is specified by the Tone Offset and the Channel Measurement Bandwidth In order to correctly calculate OIP3 due to out of band interferers a Virtual Tone is created whose power is that of an un attenuated in band tone This power level is simply the Tone Channel Power at the input plus the Cascaded Third Order Intermod Gain at the current stage This Virtual Tone Power is different 191 Simulation 192 than the Tone Channel Power measurement because the Virtual Tone Power is not attenuated by out of band rejection whereas the Tone Channel Power is For in band interferers the Virtual Tone Power and the Tone Channel Power measurement will be identical In order to make this measurement three signals tones must actually be present at the input port 1 main channel signal 2 first interfering signal tone and 3 second interfering signal tone Furthermore the spacing of the two interfering tones needs to be such that intermods will actually fall into the main or primary channel If these conditions are not met then no intermod power will be measured in
72. nearly impossible constraint for high frequency broadband measurements Scattering parameters 3 4 S parameters are defined and measured with the ports terminated in a characteristic reference impedance Modern network analyzers are well suited for measuring S parameters Because the networks being analyzed are often employed by insertion in a transmission medium with a common characteristic reference impedance S parameters have the additional advantage Linear Simulation that they relate directly to commonly specified performance parameters such as insertion gain and return loss Two port S parameters are defined by considering a set of voltage traveling waves When a voltage wave from a source is incident on a network a portion of the voltage wave is transmitted through the network and a portion is reflected back toward the source Incident and reflected voltage waves may also be present at the output of the network New variables are defined by dividing the voltage waves by the square root of the reference impedance The square of the magnitude of these new variables may be viewed as traveling power waves a1 incident power wave at the network input b 2 reflected power wave at the network input a2 incident power wave at the network output b2 reflected power wave at the network output These new variables and the network S parameters are related by the expressions bi 21811 a2812 b2 a1821 a2522 S1 b
73. of variables in the problem considerably with little effect on the accuracy of the solution There are a few cases where thinning out should not be used and they generally involve very large sections of metal which are affected too much by thinning out The Dual Mode Power Divider example is one of these cases 235 Simulation Generally the wall and cover spacing should match the problem which you ate trying to model This will give an accurate assessment not only of circuit performance but also of box resonances However this will not be possible in a few situations 1 The structure will not be in a box 2 You are analyzing part of a larger circuit and the box walls would be prohibitively large to model 3 You are designing a component such as a spiral inductor which will be reused in many different circuits so the cover height is not known In these cases you must use an approximation Set the box size so that the walls are separated from the circuit by at least 3 times the substrate thickness preferably 6 times For microstrip set the cover spacing air above to 5 to 10 times the substrate height See for more info see Box Modes See Microstrip Line for an example of the effect of wall spacing on line impedance Choosing the correct cover type is absolutely critical to getting an analysis which matches measured results The choice is usually between whether to use an open cover or a closed cover Choosing the correct c
74. parameters are difficult to view and cannot be tuned or optimized See the Designs Link to Spice File section in this User s Guide for details 51 Simulation Compression To calculate compression of a circuit a decrease in circuit transmission gain use a parameter sweep to increase the power from a low level through compression Assuming that the power input is on port 1 and the output is on port 2 the figure below shows how to plot the output power and the gain Note that the default simulation is set to the power sweep The first trace is P2 900 meaning the power at port 2 at 900 MHz The second trace is the gain Note that this is an inline equation It starts with an equals sign and the data is referred to by operator the dBm operator is required in the equation it is not needed as a direct plot as in trace 1 Graph Properties Default SinulationData or Equations Input Power Sweep Sch D ment TO Tae me color Ja A Oe E Em dbm P22900 dm P12900 Let No E Wet E let No El E o S Y o A A Als Y Auto Scale f Log Scale Min 40 Left Axis I Auto Scale Min 12 Right Axis Y Auto Scale blin a Maw 25 Mas j H Divisions fi 0 Divizions fi Other Properties Cancel Max p E Divisions fis The simulator searches for a solution until the user specified accuracy is reached or until a specified number of searching steps Sometime
75. points are needed since the individual parts are not resonant The Setup Layout Port Modes button was clicked and the checkboxes in the Setup Modes dialog box were set to indicate that those inputs are modally related Caution Do not forget to setup the modes when you ate analyzing by decomposition The Mode Setup box turns red if any inputs are modally related Improper mode setup is one of the most common errors in decomposition 252 EMPOWER Decomposition Setup Modes A similar set of steps was followed for Part2 The final step in decompositional analysis is to combine the pieces The Schematic COMBINE which does this is shown here The pieces used are NPO10 and NPO8 blocks under DEVICE in SCHEMAX for the data in PART1 and PART2 plus MMTLP8 models multi mode physical transmission lines found under T LINE for the interconnecting lines The data for the NPO10 is in WSP Simulations EMPartl EMPOWER SS and the data for the NPO8 is in WSP Simulations EMPart2 EMPOWER SS Note Some users may find it easier to write a text Netlist to combine the pieces At Eagleware we find it easier to use SCHEMAX for this purpose but you may use whichever you feel most comfortable with 253 Simulation Whenever deembedded ports are used data files suitable for the SMTLP and MMTLP models are automatically created during the LINE portion of the EMPOWER run For the MMTLP8 lines the file
76. reverse gain 20log 12 S21 and S12 are the forward and return gain or loss when the network is terminated with the reference impedance The gain when matching networks are inserted at the input output or both is described later S11 and S22 coefficients are less than 1 for passive networks with positive resistance Therefore the input and output reflection gains S11 and S22 are negative decibel numbers Throughout Eagleware material the decibel forms S11 and S22 are referred to as return losses in agreement with standard industry convention To be mathematically correct they have been left as negative numbers As such the rigorous convention would be to call them return gain Input VSWR VSWR and S11 ate related by VSWR 1 S11 ne S11 The output VSWR is related to S22 by an analogous equation A circle of constant radius centered on the Smith chart is a circle of constant VSWR The complex input impedance is related to the input reflection coefficients by the expression l Zo 1 S1 1 81 The output impedance is similarly related to S22 Stability Because S12 of devices is not zero a signal path exists from the output to the input This feedback path creates an opportunity for oscillation The stability factor K is K 1 S4 S2 2 D7 7 2 Se SaN where D S11822 S12821 From a practical standpoint when K gt 1 S11 lt 1 and S22 lt 1 the two port is unconditionally stable These are oft
77. s tones is shown above Definitions of symbols P Fundamental Tone Power IP Nth Order Intercept Point H Fundamental Tone H2 2nd Harmonic H 3rd Harmonic IM Nth Order Intermods IMn m Nth Order Intermods due to M tones SPECTRASYS uses the formulas for calculation of the nonlinear products which correspond to the small signal model Taylor expansion of the nonlinear characteristics 2nd Order Intermod Products The amplitude of the second order intermod products F2 F1 and F1 F2 are equal to the tone power level minus IP2 or in other words IM2 Ptone IP2 2nd Harmonics SPECTRASYS System The amplitude of the second harmonics are calculated as follows The amplitude of the second harmonic is equal to the tone power level minus the difference between IP2 second order intercept and the tone power level of the device 3rd Order 2 Tone Products The amplitude of the third order products 2F1 F2 2F2 F1 2F1 F2 and 2F2 Fl are equal to 2 times the quantity of the tone power level minus IP3 or in other words IM3 2 Ptone IP3 Carrier Triple Beats 3rd Order 3 Tone Products When more that two carriers are present in a channel 3rd order intermod products can be created by the multiplication of three carriers These intermods are called carrier triple beats SPECTRASYS will create triple beats for all combinations of 3 or more carriers Working out the math carrier triple beats will be
78. the Use Planar Ports for one port elements box is checked in the EMPOWER options dialog See your reference manual for details In some situations you may want to place internal ports with X or Y directed currents These ports are much trickier to use manually since they are not referenced to ground For components in your layout EMPOWER will automatically place planar port and lumped elements so this section is for background or advanced applications This figure shows the configuration of these ports These ports can be more accurate for manually connecting lumped elements to EMPOWER data since the ports are a more accurately represent the physical connection of lumped elements 261 Simulation 262 The circuit shown in below contains an EMPOWER circuit which was drawn completely in LAYOUT The schematic for this network was blank It has 3 ports ports 1 and 2 are external and port 3 is internal with current direction Along X EMPOWER will create a 3 port data file for this circuit however you must be aware that port 3 will be a series connected port and cannot be used in the normal manner The data file created by EMPOWER can then be used in GENESYS as described in the previous section using WSP Simulations EM1 EMPOWER SS The circuit on the right uses the resulting data in a complete network First a THR three port data device was placed on the blank schematic using the EMPOWER SS file from the E
79. the IM3 analysis pass Measurements SPECTRASYS The Calculate IIP3 TOD checkbox must be checked and properly configured in order to make this measurement See the Calculate IIP3 TOD section for information on how to configure these tests See the Output Third Order Intercept and Cascaded Third Order Intermod Gain measurements to determine which types of signals are included or ignored in this measurement Remember intermod bandwidth is a function of the governing intermod equation For example if the intermod equation is 2F1 F2 then the intermod bandwidth would be 2BW1 BW2 Note Bandwidths never subtract and will always add The channel bandwidth must be set wide enough to include the entire bandwidth of the intermod to achieve the expected results The Automatic Intermod Mode will set the bandwidth appropriately Values Real value in Watts Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DBM I1P3 input third order intercept in dBm Real MAG ITP3 magnitude of the input third order intercept in Watts Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DBM IIP3 DBM IIP3 DBM IIP3 MAG ITP3 MAG ITP3 MAGI ITP3 Not available on Smith Chart This measurement is the third order intercept point referenced to the output along the specified path as shown by OIP3
80. the main channel This measurement is only available during the IM3 analysis pass Note The Calculate IIP3 TOD checkbox must be checked and properly configured in order to make this measurement See the Calculate IIP3 TOD section for information on how to configure these tests See the Tone Channel Power Cascaded Third Order Intermod Gain and Total Third Order Intermod Power measurements to determine which types of signals are included or ignored in this measurement Remember intermod bandwidth is a function of the governing intermod equation For example if the intermod equation is 2F1 F2 then the intermod bandwidth would be 2BW1 BW2 Note Bandwidths never subtract and will always add The channel bandwidth must be set wide enough to include the entire bandwidth of the intermod to achieve the expected results The Automatic Intermod Mode will set the bandwidth appropriately Values Real value in Watts Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DBM OIP3 output third order intercept in dBm Real MAG OIP3 magnitude of the output third order intercept in Watts Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DBM OIP3 DBM OIP3 DBM OIP3 MAG OIP3 MAG OIP3 MAG OIP3 Not available on Smith Chart Measurements SPECTRASYS This measurement is the in
81. the mouse cursor accordingly There exists a long and short form of spectral identification The short form appears when a marker is placed on a graph The long form will appear on mouse flyover near the mouse cursor if the text is not too long and will also be displayed on the status bar of the GENESYS window The format of the spectral identification is as follows GENERAL FORMAT Line 1 Marker Frequency Marker Power Voltage Level the Frequency and Power appear on different lines for marker text on the right of the graph Line 2 Frequency Equation Origin Node Next Node Current Node 90 SPECTRASYS System Frequency Equation From the frequency equation the user can identify which source frequencies created the spectrum This equation is written like a typical mathematical equation The long form of the equation will contain the actual name of the source whereas the short form uses a short hand notation to indicate the source The short hand notation is S for source plus the index number of the source For example S1 would mean the first source listed in the Sources Table of the System Simulation dialog box S2 the second and so on regardless of the actual name of the source Frequency Equation Examples S1 2x82 Sourcel first source in the source table 2nd Harmonic of Source2 second soutce in the source table S1 52 83 Sourcel first source Source2 second source Source3 third source
82. the node sequence of the path Furthermore schematic symbols are extracted from the schematic and placed at the bottom of the level diagram These are the schematic symbols of the path of the level diagram The user can change any of the schematic element parameters by double clicking on the desired symbol directly on the level diagram The element parameters for that device will appear and the user can edit those parameters directly The effects of these changes are shown immediately on the graph SPECTRASYS System For the simple schematic below the noise power along the main path was of interest The nodes along the path are 1 5 4 and 2 The level diagram shows the noise power at each node and the schematic element between each node This schematic symbol alleviates the need to refer back to the main schematic and allows changes to element parameters BE Schi Workspace Getting Started 6 _ J RPAMP_T O COMPLERA_1 20 dB 1 dB A 0 dB pa amp A w 3 Main ATTN_1 34B Holsek3 ATTN_2 5AB EXE Workspace Getting Started 6 ae Main Path Channel Noise Power DBM CNP DBM CNP For multiple connections at a node energy can be traveling in multiple directions For details on understanding the meaning of the node measurements in this case please refer to the section on Directional Energy Level diagrams and tables contain only transmitted energy information In other words this is the tran
83. time If additional signals arrive at the amplifier input at a future time then new intermods harmonics and other spurious products will be created at the amplifier output This process continues until no additional spectrums are created If loops exist in the system schematic then the output from one element will feed the input of the next element and spectrum propagation could continue forever unless special features are placed within the software to limit spectral creation in this infinite loop SPECTRASYS has special features to control loops and limit the total number of created spectrums Loops Elements in parallel parallel amplifiers connected via a 2 way splitter at the input and combined back together with a 2 way combiner at the output can cause spectrums to be created that will propagate around this parallel path or loop If the gain of the amplifier is greater than its reverse isolation the spectrums will keep on growing as they travel around the path and will never die out we would have an oscillator The key point here is that if there are loops in the system schematic then it is very important to make sure that the element parameters are entered correctly so that signals don t grow in amplitude as they traverse around a loop The simulation will only be as good as those parameters in the model If the user is suspicious that the simulation is taking extra time then isolation parameters of the components that make up that loop
84. to provide you with an application note with instructions This chapter gives complete reference for user equations For basic operation of equations see the GENESYS Environment Equations section of the User s Guide 117 Device Data S parameters for RF and microwave devices are commonly available and easy to measure with a network analyzer They are the most accurate way to model the small signal performance of circuits However they are only valid at a particular operating point bias level Nonlinear device models are also commonly available from manufacturers but they are harder to extract from measurements The advantage of nonlinear models is that they model circuit performance at all bias levels and frequencies Moreover the model characterizes the complete linear and nonlinear performance of the devices including effects such as compression and distortion Within GENESYS are a wide range of element models Also the model and equation features provide for user creation of models However it is often necessary or desirable to characterize a device used in GENESYS by measured or externally computed data This function is provided for by the use of the ONE TWO THR FOU and NPO elements which read S Y G H or Z parameter data Note The information provided in this section applies to linear devices as modeled in SUPERSTAR Nonlinear devices should be modeled using manufacturer s parameters or a spice model link Because SUPER
85. user specifies both the Offset Frequency relative to the main Channel Frequency and the Offset Channel Bandwidth As with the Channel Frequency measurement SPECTRASYS automatically deals with the frequency translations of the Offset Channel Frequency through frequency translations elements such as mixers and frequency multipliers Both the Offset Frequency and the Offset Channel Bandwidth can be tuned by simply placing a question mark in front of the value to be tuned This measurement simply returns the Offset Channel Frequency for every node along the specified path Values Real value in MHz Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators None Examples Measurement Result in graph Smith chart Result on table optimization or yield OCF OCF OCF Not available on Smith Chart This measurement is the channel frequency of the tone channel used for intermod measurements such as IIP3 OIP3 SFDR etc The Tone Channel Frequency is the frequency of the first adjacent tone to the generated intermods The exact location of this channel is specified as a relative offset to the main Channel Frequency for the specified path This primary channel frequency plus the Tone Offset specified in the System Simulation Dialog Box is the Tone Channel Frequency As with all other frequency 175 Simulation 176 measurements SPECTRASYS is abl
86. using square brackets and are base one numbering starts at one by default A VECTOR 3 Ap 1 A 2 5 A 3 A 1 A 2 A 3 now contains 6 MATRIXG y returns a matrix 2 dimensional array of x by y real zeros Elements are accessed using square brackets and are base one numbering starts at one by default B MATRIX 2 2 B 1 1 complex 1 3 B 1 2 3 B 2 1 3 B 2 2 complex 1 3 Note for advanced users Elements can also be accessed linearly in row column order which can be useful in some situations Thus the following equations work identically to the equations just given above B MATRIX 2 2 B 1 complex 1 3 B 2 B 3 B 4 complex 1 3 3 3 GENESYS currently contains no special matrix mathematical operators All operations simply work on each element individually For example C VECTOR 2 C 1 5 C 2 3 4 D VECTOR 2 D 1 C 2 3 D 1 now equals 0 4 D 2 COMPLEX 6 E C D E is now a two element vector E 1 4 6 E 2 1 6 j6 Scalar matrix combination operators also work For instance adding a complex number to a vector adds the complex number to every element of the vector F VECTOR 2 F 1 1 F 2 2 111 Simulation 112 G COMPLEX 3 4 H F G H 1 4 34 H 2 5 j4 Matrices and vectors are safe out of bounds access is always caught If an out of bounds index is used the first element is used instead If the variable being indexed is not an array its val
87. within the channel and it will appear that intermods are not present Remember intermod bandwidth is a function of the governing intermod equation For example if the intermod equation is 2F1 F2 then the intermod bandwidth would be 2BW1 BW2 Note Bandwidths never subtract and will always add For third order intermods it the bandwidth of the two interferers are identical then the bandwidth of the resulting intermods will be 3 times that of the single interferer This mode is enabled when the Manual Advanced checkbox has been checked 17 Simulation 78 Automatic 2 Tone In this particular mode SPECTRASYS will create the 3 sources needed to calculate intermods and intercept points These signals will be totally transparent to the user when looking at any spectrum plots and can only be accessed through intermod measurements Some additional information such as the Input Port Tone Spacing Gain Test Power Level and the 2 Tone Power Level parameters will need to be specified by the user Three sources are needed to make intermod measurements The first source is created in the main channel at the channel frequency and is used to determine the in channel gain of the chain The user must specify the level of this source through the Gain Test Power Level parameter This level should be above the noise floor and be well below the level that would cause non linear behavior The Input Port specifies the port where t
88. you follow along with the following examples The viewer displays current distributions as two or three dimensional graphs The viewer has several modes that are used to view various components of the currents from different view perspectives The best view of most problems is often found by minor adjustments of the view orientation The following examples include a few examples of 273 Simulation 274 such adjustments The examples are simple problems selected because the results are predictable Nevertheless they are interesting and illustrate concepts which may be applied to more complex problems Consider the possible graphs for a simple line segment analysis The schematic file for this example is METR16 WSP It contains description of a segment of the 50 Ohm standard stripline Rautio 1994 that is also discussed in the Examples Chapter The segment is 1 4423896 mm wide by 4 996540 mm long and the box size along the z axis is 1 mm The segment length is 90 degrees at 15 GHz and 180 degrees at 30 GHz Load METR16 WSP in GENESYS Run the viewer by selecting Run EMPOWER Viewer from the right click menu of Simulation EM1 The default plot seen in the main window is an animated surface electric current density distribution function reflecting the surface currents in the strip plane At the initial time t 0 it will look similar to the graph shown below empower Viewer V6 5 LOL File View xY a Real Soia Freq GHz
89. 1 AddToGain 25 TotalGain Gain AddToGain This example takes the gain in dB DB S21 of the design Filter using the simulation setup in Linear1 and places the result into the variable Gain For a complete explanation of this syntax see the Measurements section of this manual Note that Gain now contains swept data DB S21 vs frequency Next the variable AddToGain is added Equation Reference to each data point The variable AddToGain can be tuned or optimized which will directly affect the value of TotalGain There ate several important things to know about post processed data Any measurement described in the measurements section of this manual is available for use in post processing To get simulation data the expression must contain a period For example A DBJS21 will not work but A DB S21 will This is most important if you take advantage of the USING statement see below Post processed equations can be used directly in a graph or other output by putting in front of the measurement All rules of this section including the period rule above must be followed To get simulation data you must always use a measurement operator For example A Linear1 Filter S21 will not work but A Linearl Filter DB S21 will Post Processed variables can be mixed with regular variables as in the example above Frequency dependent post processed variables can be used in part values The data will be sampled interpolated
90. 1 4521 3 07963 1 612 4 57954 1 6165 ESTOS 1 03834 1 331 31 4521 3 07963 0 0 When designing an amplifier the first step is to examine the stability circles of the device without the matching circuit present The grounding which will be present at the emitter or source should be included in the analysis This stability data is used to 1 add stabilizing components such as shunt input and output resistors for bipolars or inductance in the source path for GaAsFETs and to 2 select an input and output matching network topology which properly terminates the device at low and high frequencies for stability In the example above matching networks with a small series capacitor adjacent to the device would insure capacitive loads at low frequencies thus enhancing stability This is probably sufficient for the input However considering that device S parameter data is approximate and since the output plane of this device is more threatening it would be prudent to stabilize this device in addition to using series capacitors Note Stability should be checked not only at the amplifier operating frequencies but also over the entire frequency range for which S Parameter data is available Matching One definition of network gain is the transducer power gain Gt Transducer power gain is the power delivered to the load divided by the power available from the soutce Gt P delivered to load P available from source 35 Simulation 36
91. 1 a1 a2 0 Si2 b1 a2 a1 0 S21 b2 a1 a2 0 S22 b2 a2 a1 0 Terminating the network with a load equal to the reference impedance forces a2 0 Under these conditions Su b1 a1 S21 b2 a1 S11 is then the network input reflection coefficient and S21 is the gain or loss of the network Terminating the network at the input with a load equal to the reference impedance and driving the network from the output port forces a 0 Under these conditions S22 b2 22 Si2 bi az S22 is then the network output reflection coefficient and S12 is the reverse gain or loss of the network Linear S parameters are unitless Since they are based on voltage waves they are converted to decibel format by multiplying the log of the linear ratio by 20 It is not always obvious whether an author is refering to linear or decibel parameters To avoid this confusion the book Oscillator Design and Computer Simulation and Versions 5 4 and earlier of SUPERSTAR use C for linear S parameters and S for the decibel form This is somewhat unconventional Version 6 0 and later of GENESYS also supports the convention 33 Simulation 34 MAGJ S21 which is linear and DB S21 which is the decibel form With reflection parameters the linear form is often refered to as a relection coefficient and the decibel form as return loss Si1 dB input reflection gain 20 log S11 S22 dB output reflection gain 20 log S22 S21 dB forward gain 20log 21 S12 dB
92. 180 String variables can be used in the Equation Window A ABC B DEF C A B After this code C ABCDEF Concatenation is the only operator currently defined for string variables all other operations give undefined results If you create a model and want it to take a string variable as a parameter put a tilde in front of the parameter name in the Model Properties dialog box to indicate that it is a string Furthermore if the parameter starts with the word or is the word FILENAME a browse button will be given to the user in the schematic part dialog box gt GENESYS allows you to create vectors and matrices in the Equation Window Each element in a vector or matrix can hold any type of data real complex string swept or even a nested array Equations are made most easily with the array concatenation operator semi colon For example X 3 4 5 Y X 1 X 3 Y contains 8 3 5 places an array of values 3 4 and 5 into variable X and uses these values in Y To make a two dimensional array use parenthesis X 153233 5 45536 73839 Y X 2 2 Y contains 5 The operator can be combined with other operators and complex values Equation Reference W 1 2 3 X 83sqr 4 3 5 Y COMPLEX W X Y array 1 j8 35 3 35 There are also two functions which you can use to create arrays in your equations VECTOR x returns a vector 1 dimensional array of x real zeros Elements are accessed
93. 2 1st mixer image channel The only difference is between these two channels are their frequencies one is at the Channel Frequency and the other is at the Mixer Image Frequency See the Channel Noise Power and Image Channel Noise Power measurements to determine which types of signals are included or ignored in this measurement Values Real value numeric Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DB IMGNR _ mixer image rejection ratio in dB Real MAG IMGNR numeric value of the mixer image rejection ratio Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DB IMGNR DB IMGNR DB IMGNR MAG IMGNR MAG IMGNR MAG IMGNR Not available on Smith Chart This measurement is the integrated power of the image channel from the path input to the first mixer After the first mixer the Mixer Image Channel Power measurement will show the same power and the main channel power Any energy at the image frequency can seriously degrade the performance of a receiver Even unfiltered noise at the image frequency will be converted into the IF band and degrade the sensitivity by as much as 3 Measurements SPECTRASYS dB The image frequency measurements are provided to help the designer understand the impact of the image frequency on the performance of the receiver Since SPECTRASYS knows the C
94. 2 43 52 119 OS 106 107 110 112 Concatenatlon iia 110 ete ce cn eo ees 3 Console Widow sescssssssssssessssssssesssssssessen 230 ASOC a o ne at 125 OT O ee ee nt 141 AN posix EN re 107 Ge ee een 110 141 Anto MAILE eee GRINS Sarreh i E A A NN 167 Automatic Port Placement dina 260 Convergence svrcessssesssessesenee 41 43 52 53 287 Automatic Recalculation essesse 41 43 Copla ries 23l Automatically Caleu eea 50 Simulation 312 COPPET ari a ci 217 COS O 107 COST yaa N badss 107 COUNT T a A N 107 110 112 Coupled Microstrip nos ZIA CONCE PICO i a teueea Goxacceevee 236 Bro Cos T com ree errr E E EE 236 COVE tud 217 241 259 Creating New Data Plena EER 120 O O 120 Curent DI di 241 Current Viewer Dita 303 Current VON ASC ts ajos 203 D Dodo 1 Data Plena 119 120 122 DT A A aes eee teense 112 141 143 DD MOU A A 145 AA toad eueen diabetes N 107 Duties EN 107 PEANG srta ira 141 143 DD BANG S60 sr tata 143 DDN O pe at Eat A 52 DEMAG rira ace emren coer ter 141 D Oe idos 41 DEA dodo 41 DEA tae ado 5 8 DE Analysis Over tance teak 41 DE DAS ta baaa 10 PEDANE oca demnecesiemebaetatianeiuaimnts 1 PEC tenaaan A ails 5 EY eG ace se vaseelec cesesaciunctetstodtes eae vecestasocsanencet 5 8 DEV Olsen 5 10 DecoMpPOStHO Matan 245 249 250 257 Deembedded ports 260 DEE Mi Ded Ce race 241 243 305 De Embedding Algorithm esseere 297 Peralt OPEO Pu puea E 141 143 Default Simulation Data coonnccnnnncccnnnic
95. 30 30 2000 2600 2000 2600 Freq MHz Freq MHz DB S21 DB S11 DB S21 DB S11 Error 0 Lumped Elements The first example in this section required several data points to find the exact notch frequency This second example only used 4 data points and produces data very close to the SUPERSTAR simulation This is because the capacitors which load the coupled lines causing resonances at the center frequency were removed during the EMPOWER simulation This effectively removes the resonances from the simulation range producing a flat response from the open coupled lines Since a flat response is well suited for linear interpolation few data points are required in the EMPOWER simulation In the EMPOWER options dialog the Co Simulation Sweep box is used to set up a simulation with more points after lumped elements are added 214 EMPOWER Operation When GENESYS uses the EMPOWER results 1t replaces the lumped capacitances resulting in the bandpass response shown in the previous section Real Time Tuning As stated before GENESYS creates ports internal to a layout structure containing lumped elements before invoking EMPOWER During calculation EMPOWER creates s parameter data with port data for all ports whether internal or external This allows GENESYS to tune the lumped elements while still using the EMPOWER data To see an example of tuning 1 Click inside the C2000 prompt in the Tune Window 2
96. 4 L F Richardson The differed approach to the limit 1 Single lattice Philos Trans of Royal Society London ser A 226 1927 p 299 349 A Premoli A new fast and accurate algorithm for the computation of microstrip capacitances IEEE Trans v MI T 23 1975 N 8 p 642 647 EMPOWER References G I Marchuk V V Shaidurov Difference methods and their extrapolations Spr Verlag 1983 originally published in Russian 1979 A G Vikhorev Yu O Shlepnev Analysis of multiple conductor microstrip lines by the method of straight lines Journal of Communications Technology and Electronics 1991 N 12 p 127 129 originally published in Radiotekhnika 1 Elektronika v 36 1991 N 4 p 820 823 M Hammermesh Group theory and its application to physical problems Pergamon Press Oxford 1962 I J Good The inverse of a centrosymmetric matrix Technometrics Journal of Statictics for Physical Chemical and Engineering Science v 12 1970 p 925 928 P R Mclsaac Symmetry induced modal characteristics of uniform waveguides Part I Summarty of results Part Theory IEEE Trans v MI T 23 1975 N 5 p 421 433 W T Weeks Exploiting symmetry in electrical packaging analysis IBM Journal of Research and Development v 23 1979 N 6 p 669 674 A B Mironov N I Platonov Yu O Shlepnev Electrodynamics of waveguiding structures of axisymmetrical microwave integrated circuits Journal of
97. 59 48 32 2 0 39 166 3 54 60 080 58 46 37 2 5 41 156 2 91 53 095 61 44 40 3 0 44 145 2 47 43 115 61 43 48 3 5 46 137 2 15 33 133 58 43 58 4 0 46 127 1 91 23 153 53 45 68 4 5 47 116 1 72 13 178 50 46 75 5 0 49 104 1 58 3 201 47 48 82 6 0 59 81 1 34 17 247 36 43 101 121 Simulation 122 IFREQ Fopt GAMMA OPT RN Zo 0 1 1 2 12 3 0 17 0 5 1 2 10 14 0 17 1 0 1 3 05 28 0 17 2 0 1 7 30 154 0 16 4 0 3 0 54 118 0 35 A sample 1 port Z parameter data file is shown below This data file could be used to specify a port impedance that varied over frequency Notice that the data is real and imaginary RI impedance Z data taken across several frequency points 13 90 to 14 45 MHz that has been normalized to 1 ohm R 1 MHZ ZRIR1 13 90 30 8 29 2 14 00 31 6 6 6 14 05 32 0 4 7 14 10 32 4 16 0 14 15 32 7 27 2 14 20 33 1 38 4 14 25 33 5 49 5 14 30 33 9 60 7 14 35 34 3 71 7 14 45 35 1 93 7 Most device files provided with GENESYS are S parameter files in the usual device configuration typically common emitter or common source Devices you add to the library may use the ground terminal of your choice However if you always keep data in a consistent format record keeping chores are greatly minimized Export S Parameters in the File menu writes S parameter data from any simulation or data source This output data file has exactly the same format as S parameter files used to import data Th
98. 6 A A E E 36 A ethene et ers Anand 141 MOOR A Bate ae eth th 141 Y PAM 120 e lets wets cere osname 32 120 305 DE i A TORTE E E E 141 Z Z PAES o e EE 141 LME an 217 2313239 278 219 281 Ae ADIGE CEE POLES ia 224 259 TENNIS acto A A 141 EN AAA rated secia trees ated ane ese 36 NA 36 O O fac sh ech ETT 141 A aes Sat BSUS Ss 32 A esac A EE eee 141 ZAPU E E E E E E T 141 317
99. 6 dB higher that the 3rd order 2 tone products This calculation of the triple beat level assumes that the amplitude of all input sionals is the same The frequency combinations of the carrier triple beats are as follows KRFA F1 F2 F3 Fic BZ ES Flt BZ F3 3rd Harmonics The amplitude of the third harmonics are 9 542 dB below the 3rd order 2 tone products Measurements SPECTRASYS creates intermods for all input sources driving nonlinear elements such as amplifiers and mixers Cascaded intermod equations are NOT used by SPECTRASYS There are two serious drawbacks using the cascaded equations See the section Cascaded Intermod Equations for additional information Also see the Calculate IIP3 TOD section Linear elements will not create intermods However these elements will conduct them from prior stages where they were created The Total Third Order Intermod Power TIM3P can be separated into two distinct groups of intermods The first group is Generated intermods and the second is Conducted intermods from a prior stage SPECTRASYS is able to separate intermods into these two groups This allows the user to quickly determine the weak intermod link in a cascade of stages This total is the non coherent sum of the generated and conducted third order intermod power Generated Third Order Intermod Power GIM3P is the total third order intermod power that is created in a particular stage This measurement will only show the i
100. 616 5625 5632 5670 5720 5733 5760 5775 5824 5832 5850 5880 5940 6000 6006 6048 6075 6125 6144 6160 6174 6237 6240 6250 6272 6300 6318 6336 6370 6400 6435 6468 6480 6500 6552 6561 6600 6615 6656 6720 6750 6804 6825 6860 6864 6875 6912 6930 7000 7007 7020 7040 7056 7128 7150 7168 7200 7203 7280 7290 7350 7371 7392 7425 7488 7500 7546 7560 7644 7680 7700 7722 7776 7800 7840 7875 7920 7938 8000 8008 8019 8064 8085 8100 8125 8190 8192 8232 8250 8316 8320 8400 8424 8448 8505 EMPOWER Tips 8575 8580 8624 8640 8736 8748 8750 8775 8800 8820 8910 8918 8960 9000 9009 9072 9100 9152 9216 9240 9261 9360 9375 9408 9450 9477 9504 9555 9600 9604 9625 9702 9720 9750 9800 9828 9856 9900 9984 10000 Using Thick Up or Thick Down metal will greatly increase the complexity of an EMPOWER run as all metal layers must be duplicated for the top and bottom of the thick metal and z directed currents must be added along the sides of all metal The detailed of defining metal layers is found in the EMPOWER layers dialog box as follows Metal Layers All metal layers from the General Layer Tab are also shown in the EMPOWER Layer tab These layers are used for metal and other conductive material such as resistive film The following types are available e Lossless The layer is ideal metal e Physical Desc The layer is lossy These losses are described by Rho resistivity relative to copper Thickness and Surface Roughness e Electrical Desc The laye
101. 8 770 780 784 792 800 810 819 825 832 840 858 864 875 880 882 891 896 900 910 924 936 945 960 972 975 980 990 1000 1001 1008 1024 1029 1040 1050 1053 1056 1078 1080 1092 1100 1120 1125 1134 1144 1152 1155 1170 1176 1188 1200 1215 1225 1232 1248 1250 1260 1274 1280 1287 1296 1300 1320 1323 1344 1350 1365 1372 1375 1386 1400 1404 1408 1430 1440 1456 1458 1470 1485 1500 1512 1536 1540 1560 1568 1575 1584 1600 1617 1620 1625 1638 1650 1664 1680 1701 1715 1716 1728 1750 1755 1760 1764 1782 1792 1800 1820 1848 1872 1875 1890 1911 1920 1925 1944 1950 1960 1980 2000 2002 2016 2025 2048 2058 2079 2080 2100 2106 2112 2145 2156 2160 2184 2187 2200 2205 2240 2250 2268 2275 2288 2304 2310 2340 2352 2376 2400 2401 2430 2450 2457 2464 2475 2496 2500 2520 2548 2560 2574 2592 2600 2625 2640 2646 2673 2688 2695 2700 2730 2744 2750 2772 2800 2808 2816 2835 2860 2880 2912 2916 2925 2940 2970 3000 3003 3024 3072 3080 3087 3120 3125 3136 3150 3159 3168 3185 3200 3234 3240 3250 3276 3300 3328 3360 3375 3402 3430 3432 3456 3465 3500 3510 3520 3528 3564 3575 3584 3600 3640 3645 3675 3696 3744 3750 3773 3780 3822 3840 3850 3861 3888 3900 3920 3960 3969 4000 4004 4032 4050 4095 4096 4116 4125 4158 4160 4200 4212 4224 4290 4312 4320 4368 4374 4375 4400 4410 4455 4459 4480 4500 4536 4550 4576 4608 4620 4680 4704 4725 4752 4800 4802 4851 4860 4875 4900 4914 4928 4950 4992 5000 5005 5040 5096 5103 5120 5145 5148 5184 5200 5250 5265 5280 5292 5346 5376 5390 5400 5460 5488 5500 5544 5600 5
102. 9 Set the category to SELF _RESONANT wsp or lt AI gt to see every available model Then change the model to SELF_RESONANT_CAPACITOR as shown below and click OK Change Model Ed ee Cancel Category c program files genesys version 7 0 examples SELF_RESONANT wsp New Model AMAT da 130 User Models 20 Now the capacitor dialog changes to contain all the new model parametets as shown below Part Properties For SELF_RESONANT_CAPACITOR 21 Right click on the Simulations Data node in the Workspace Window as shown below Outputs Equations J Substrates Optimizations Yield 22 Add a linear simulation and enter the parameters as shown below 131 Simulation Linear Simulation Properties _ x 23 Right click the Outputs node in the Workspace W Window as shown below g orkspace Window E a DesignsMoadels ya Schl Schematic al a peli Boson Linear O to 3000 101 pts io IM Add Rectangular Graph 24 Add a rectangular graph and plot S11 The figure below shows the plot from this example This plot of S11 shows a return loss minimum at 1500 MHz the capacitor s self resonant frequency 132 User Models BE Plot of 511 olk o 1500 Freg MHz Model Properties To open Create a new User Model Model Properties Ed ET IE O TI E Parameter 7 Note ln GENESYS 8 0 all parameters are converted to GENESYS standard units
103. 90 ipat Third Order Mater ee pe 9 ga ae lla 190 Output atra Order Intercept OUP rai 191 Conducted Third Order Intermod Power CIM3P h vcs ents seaceceecamemeareestaetaratecetenacenanss 193 Generated Third Order Intermod Power GIM SP darian 194 Total United Order nterimod Power IM 195 Total Node Power UN 196 OEI odioso 197 TG ACUI NS AE E E E E E ea A T E EE 197 EXAMPLES A A A NAAA AAA ARA 198 Creatine a AY OU assed diene ed cscs cu crane o os cabida 198 Creatine a lay Out Wit OU a SCI atada dada 199 BOX DINEO OS ad 200 General betas la it 201 EMPOWER TAE di 201 TPA ihe Layou arpa a sias 203 Genterino te La UL A cen lysates aoatsctncans Sac veunitee 205 Prene EMPOWER Polis ide 205 Simular tie Lavoro de 206 WS WA Resulta 208 Vino he NG veria as 210 Creating a Layout roman Existing Schcmatc noc 211 Suke Slay Ona a a a E T aS esas eaceee 213 Eunped ener a A RO 214 Reak Time TUI ASA A A di 215 ON EVEN dt toi rA 2D SIMULA TO St E A E A E E ARES 217 SDBDSIMULCLATOR a 217 22 DSIMULA TOR idas 217 Das COMU a iO iio A 1 OA E Lo AECE o e rte een ee te er ree re ee er eer 221 Vialholes and LD lo eii ad 224 ENDOSO Ad 225 EMPOWBR O pudiera AE E AEE 225 General Tarta 226 a A EEA ern sn ane ee 227 TON ANCS d abit tots 229 Table Of Contents Console WiIIdO Wi acia 230 DAA RIOS A ana 231 A O TN 233 A E a e a 233 Maxman Atico tia A A A AO as 234 MS as 234 MN 25 Wal Cover Pac 236 Cover PE OA aci 236 LOS AAA A AA A 236 A O TE OT GAT
104. AsFET transistor SUPERSTAR circles are plotted at the frequency of the first marker in this case 2500 MHz Marker 1 is plotted at the center of the smallest circle the point of maximum gain The gain at the circumference of each circle of increasing radius is 1 dB lower than the previous inside circle 37 Simulation 38 Response SPARAM 5D AHN PT 7 pi A AA HY DEGU DE GU2 DEJEU DE GU2 8500 2500 3500 8500 12000 3 5764 10 9031 42 2187 2 40433 5 35212 4 55296 0764 0 The arc which is orthogonal to the gain circles is the locus of smallest circle center points from the lowest to highest sweep frequency Tuning the first marker frequency moves the center of the circles along this arc Notice that a complex conjugate match at the input improves the gain by over 3 dB in relation to an unmatched 50 ohm source impedance However matching the output provides less than 1 dB gain improvement An examination of the device S parameter data at 2500 MHz reveals that the output is originally closer matched to 50 ohms and it is not surptising that a matching network would be less beneficial Noise Circles To achieve the best available noise figure from a device the correct impedance must be presented to the device The impedance resulting in the best noise performance is in general neither equal to 50 ohms or the impedance which results in minimum reflection at the source The Avantek AT10135 GaAsFET transistor
105. CTRASYS 6 Set the Signal Type to CW Narrow The Center Frequency to 100 MHz and the Power Average to 50 dBm 7 Click OK to lado the cd created source System Simulation Parameters General o Caio Compost een Opens _Becleale Now nf a z a E 8 Click OK to accept the system simulation parameters SPECTRASYS will automatically calculate 9 Right click on the Outputs tab in the workspace window 10 Select Add Rectangular Graph Enter the name Output Spectrum 11 Click Measurement wizard to add a new measurement 12 Select Simulation System1 Sch1 Composite Spectrum and press Next 13 Select Pport power at a port node select item P2 and press Finish 14 Click OK to close the Graph Properties dialog box You will see a simple graph with the output spectrum Note This graph will be easier to read if you make it larger than the default size 15 To make this graph easier to see and understand we can switch to spectrum analyzer mode Double click on System1 in the workspace window 16 Enter 200 MHz for Ignore Spectrum Frequency Above 17 Click on the Composite Spectrum Tab Check Enable Analyzer Mode Press OK Your graph should now look more like a spectrum analyzer displaying the data including random noise 19 Simulation BE Output Spectrum Workspace 2 Add Simulation mM EL SS O OA E O A E a Frequency MHz DBM F2 Note The two total spectrums shown
106. DOL ena aa a a 294 Nume tical Acceleration Procede S aana A 296 De sl pulolsroceiualivallscesaueasclmermre rere AO 297 OEA daa 299 Text Pues ys Dinar bles lalo 300 FICE EOS ONS inde 300 EMV EMPOWER Viewer Fles icneia e o NE 301 Eheb Laine Data TUES apiet ainia AA 301 BECIE ETE SNCS A S A T E E A E E A eapapadanneect 302 PEX Current Viewer Lata Ee Ea E EE E 303 RaR a Ri Dot lapped ance PIES orn is 303 RGP CNE Da T E e aa E A ieee reer tr Tere 304 RA Fregueney vse Impedance Plessen nie 304 oor Parameter o 304 Table Of Contents APT VOPOlOR yy PESA 304 WSOP Works pace Plenos 305 LOGS eerie tg Voor Ih gill cy o E E E men eee reer See Wey re eee Se 305 ADORO et BackUp Pl tia A AA 305 General BIKOTE a E a aca 307 The Metodo lie a tren ere ee ee eter er eee eee ree 308 Richardson EXA A a 308 Sy MEE Pro Cessna ccs tc teks tetas cua taal rece arasatusctsovsbe chat dennis natealac ude tebetba bien ien ruse eio Ms aetaneees 309 EMPOWER Enci do Theory and AGO rl tiie id A 309 Vest Examples and COm paris Ons ii ben ttecaiiouli eon ila Sieecdlinis 310 Overview GENESYS supports several different types of simulations allowing the exploration of a complete range of circuit performance e DC Simulation nonlinear HARBEC e Linear S Parameter Simulation e Planar 3D Electromagnetic EM Simulation EMPOWER e Harmonic Balance Simulation nonlinear HARBEC e Spectral Domain System Simulation SPECTRASYS Additionally the f
107. Deselect Hide MS DOS file extensions for file types that are registered and click OK Different versions of Windows may have slightly different procedures EMPOWER File Descriptions MV Binaty Viewer data L1 L2 etc Port deembedding and line data for port 1 2 etc E specified deembedding file name S Parameter results Netlist for EMPOWER Y Parameter results C l SS RG Backup All files with either a name or an extension starting with tilde et are backup files and can be safely deleted Written by EMPOWER Type Binary Can be safely edited No Average size 10 to 100Kbytes but may be larger Use Data for viewing currents or voltages EMV files EMPOWER Viewer files are completely self contained files containing all information needed by the viewer to display currents and voltages for a circuit These files contain information about the box and the grid mapping of the circuit as well as actual complex current or voltage values at each frequency EMPOWER creates an EMV file whenever Generate Viewer Data is checked or the In option is specified EMV files can only be read by the EMPOWER viewer If you want to generate viewer data for import into other programs you should generate a PLX text file For more information on viewer files the Viewer section Written by EMPOWER Type Binary Can be safely edited No Average size 1 to 5Kbytes but may be larger 301 Simulation 302
108. E EEE te tice E E A E E 43 A TAR 107 EN 107 EN acacia neat eae at E 107 A 43 O A T 119 PREC casado da 112 PCC o E a adi 31 POETICO DA eea AE 43 53 PUNC TION tras 103 116 G ES de Ia CLEE a e EE A R 141 Gun Gir S E E 32 37 141 A E T AE A 143 General Background References 0 307 Gercral ay et eA 217 General aA Vers era A 201 General ura 287 288 Generalized CA 219 Generalized S PatametetS cecce 247 303 Generate Viewer Data 237 265 277 279 281 301 gt REO 107 GETINDEPVATUE cnica 107 112 GETVALUE uraste 107 112 GEIVYALUEA unido 107 112 GOSA n AT 55 A NR NOR ODES REE nn er SRE 143 A A A eee toe E 36 GN RM ei ene ner ree E PE WN Pee NOTRE Aone 36 GEA A 32 36 37 141 143 A 141 A A 41 43 a A 41 GO PT 00 122 141 143 A A ee ROPER arene eee 103 I ee pata a a oak once Ale oie A 35 37 A NA 141 Oral tral E o er ere ee 143 Greater A ee 106 TES TUCU odds 288 o A A eae eee 221 234 259 291 Grid Green s Function e se ssssssressessssesssesse 293 Gad ENA UO uo dd 302 Ground PAN terse cnosssrctesiecnt tececanctesteess 1 241 259 Gt35 A O eg oe eee 37 GUI Carriles ci e O mr re a 141 soar ss rc tances al ease teeta 37 GUZ Cit les resets vets eset casas 141 Index H ERE 141 AA A 12 43 52 138 HARBEC OPONSE naini r 43 52 53 HARBEC Popup Mental 50 HARBEC Convergence Issues sss 52 HARBEC Measurements isareti 52 HARBEC Optimization oe 53 Harmonic Balante nuria locos 43 52 53 HB CPI Reir t
109. Gl ANGI radius Linear GU2 unilateral gain circle at port 2 center MAG ANGI radius Linear 157 Simulation 158 Available on Smith Chart and Table only The Stability Factor and Measure parameters are real functions of frequency and are available for 2 port networks only These parameters aid in determining the stability of the 2 port network If S12 of a device is not zero a signal path will exist from the output to the input This feedback path creates an opportunity for oscillation The stability factor K is K 1 Su S2212 D C S12 Sal where D S11822 S12921 From a practical standpoint when K gt 1 S11 lt 1 and S22 lt 1 the two port is unconditionally stable These are often stated as sufficient to insure stability Theoretically K gt 1 by itself is insufficient to insure stability and an additional condition should be satisfied One such parameter is the stability measure B1 which should be greater than zero BISTE S11 2 S22 2 D 2 gt 0 Note See the section on S Parameters for a detailed discussion of stability analysis Values Real value versus frequency Simulations Linear Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators None Examples Measurement Result in graph Smith chart Result on table optimization or yield K stability factor stability factor B1 stability measure stability measure x Not available on Smith Chart A output stabilit
110. IN DB GAIN MAG GAIN MAG GAIN MAG GAIN Not available on Smith Chart This measurement is the image frequency from the input to the first mixer Any energy at the image frequency can seriously degrade the performance of a receiver Even unfiltered noise at the image frequency will be converted into the IF band and degrade the sensitivity by as much as 3 dB The image frequency measurements are provided to help the designer understand the impact of the image frequency on the performance of the receiver Since SPECTRASYS knows the Channel Frequency of the specified path it also has the ability to figure out what the image frequency is up to the 1st mixer After the 1st mixer the Image Frequency measurement will show the main channel frequency This measurement will show what that frequency is This image frequency is used to determine the area of the spectrum that will be integrated by the Mixer Image Channel Power measurement to calculate the image power For example if we designed a 2 GHz receiver that had an IF frequency of 150 MHz using low LO side injection then the LO frequency would be 1850 MHz and image frequency for all stages from the input to the first mixer would be 1700 MHz All noise and interference must be rejected at this frequency to maintain the sensitivity and performance of the receiver Values Real value in MHz Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commo
111. In order for SPECTRASYS to be able to locate the path a signal source must be present on the from node If a source has not been created or has been disabled then SPECTRASYS will not be able to locate the path The from node and the to node can be any node in the schematic and is not restricted to an input or an output port However the first node in the path node sequence must be the from node and the last node must be the to node All nodes in the path must be separated by commas and the thru nodes can be in any order Two functions exist on the Paths page of the System Simulation dialog box shown below to aid the user in specifying the path The first is an Add All Paths From All Sources button All possible port to port paths will be added to the System Simulation for all ports that have a source defined If no sources have been defined then no paths will be added If the number of paths becomes very large then the user will be prompted before adding the paths The second is an Add Path button which will prompt the user for the 1 Path Name 2 From Node and 3 To Node See the System Simulation Parameters Paths section for additional information Path Frequency 83 Simulation 84 This is the same as the Channel Frequency See Channel Frequency for more information Directional Energy Node Voltage and Power When more than two connections occur at a node a convent
112. MAG CNP magnitude of the channel noise power in Watts Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DBM CNP DBM CNP DBM CNP Measurements SPECTRASYS MAG CNP MAGI CNP MAG CNP Not available on Smith Chart This measurement is the total integrated power in the main channel identified by the Channel Frequency and the Channel Measurement Bandwidth of the specified path This measurement includes ALL SIGNALS INTERMODS HARMONICS and NOISE traveling in ALL directions through the node that fall within the main channel For example if the Channel Measurement Bandwidth was specified to 03 MHz and the Channel Frequency was 220 MHz then the CP is the integrated power from 219 985 to 220 015 MHz Values Real value in Watts Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DBMI CP channel power in dBm Real MAG CP magnitude of the channel power in Watts Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DBMI CP DBMI CP DBM CP MAG CP MAG CP MAG CP Not available on Smith Chart This measurement is the total integrated power in the main channel identified by the Channel Frequency and the Channel Measurement Bandwidth of the specified path This measurement includes ONLY SIGNALS ORIGINATING on the begi
113. MGP MAG IMGP Not available on Smith Chart This measurement is the ratio of the Channel Power to Image Channel Power along the specified path as shown by IMGRJ n DCP n IMGPT n dB where n stage number For this particular measurement basically two channels exist both with the same Channel Measurement Bandwidth 1 main channel and 2 1st mixer image channel The only difference is between these two channels are their frequencies one is at the Channel Frequency and the other is at the Mixer Image Frequency 185 Simulation 186 See the Desited Channel Power and Image Channel Power measurements to determine which types of signals are included or ignored in this measurement Values Real value numeric Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DB IMGR mixer image rejection ratio in dB Real MAG IMGR numeric value of the mixer image rejection ratio Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DB IMGR DB IMGR DB IMGR MAG IMGR MAG IMGR MAGT IMGR Not available on Smith Chart This measurement is the spurious free dynamic range along the specified path as shown by SFDR n 2 3 IIP3 n MDS n dB where n stage number The Spurious Free Dyanmic Range is the range between the Minimum Detectable Discernable Signal
114. MISOIP3 DBMISOIP3 MAGJ SOIP3 MAGISOIP3 MAG SOIP3 Not available on Smith Chart This measurement is the output saturation power specified in the element parameters for the particular stage This parameter is currently only available for the SPECTRASYS non linear behavioral models such as amplifiers and mixers For all stages where this parameter is not specified a large default value of 100 dBm is used Values Real value in Watts Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DBMI SOPSAT stage output saturation power in dBm Real MAGJISOPSAT numeric value of the stage output saturation power Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DBM SOPSAT DBM SOPSAT DBM SOPSAT MAGJSOPSAT MAG SOPSAT MAG SOPSAT Not available on Smith Chart This measurement is the third order intercept point referenced to the path input along the specified path as shown by IIP3 n OIP3 n CGAINIM3 n dBm where n stage number This measurement simple takes the computed Output Third Order Intercept and references it to the input by subtracting the cascaded gain of the intermod path from the input to the current stage The last IIP3 value for a cascaded chain will always be the actual input third order intercept for the entire chain This measurement is only available during
115. MPOWER run An input and output were added on nodes one and two of the THR block the ground was added to the ground node and a capacitor was connected from port 3 to ground This has the effect of putting the capacitor across port 3 in the EMPOWER simulation The rules to follow for Along X and Along Y internal ports are simple e Do not attempt to use them for transistors or other 3 terminal or more devices e Set the Current Direction of the EMPort to Along X along the x axis if the current along the component flows from left to right as on the layout on the left above Set the Current Direction of the EMPort to Along Y along the y axis if the current along the component flows from top to bottom as if the capacitor were turned 90 degrees from the one on the layout above EMPOWER Lumped Elements and Internal Ports e Connecting a lumped element in SCHEMAX from the port to ground when you use the resulting data is equivalent to connecting the lumped element accross the leneth of the port in the LAYOUT This does not mean that the component is grounded It simply means that the component is connected accross the port This concept is key to understanding X and Y directed ports When the S Parameters of MYNET are displayed in a graph you see the resulting S Parameters of the entire circuit Often when a circuit contains lumped elements you can use very few frequency points for the EMPOWER runs Since the
116. NC radios 217 285 A E A EA E E A EE 304 TPL ICar e E EER 221 Mia o A A 35 36 Transistor A O cee state tenis Gaatens deans 8 DO CU E aO 5 PE R es 5 8 10 38 119 122 Transmission ad 39 Transmission Nines oana ds 1 MA N 27 TD E A 119 IO DOL A caase 32 34 35 37 TWO POE ERORE E A 120 Two port S PAramete Seer 327119 U Undersampled mundi 52 Valker basenie a ic 141 Ms A A A 37 ial petal Gate cles eu daen 141 Unnormalized Y parameter data eee 120 Unstable tonada 141 Up to litiasis O 50 Use Krylov Subspace Method eee 43 Use Previous Solution As Starting Point 43 52 Usted dadas 235 User Functons tia 1 116 User Model Pixatniple vucicin land 127 USING usas 112 Using Equation Resultando 146 Using Non Default Simulation Data 145 V e E E as E O E 110 Valie Mode DION asun 213 Variable Valles 106 o A A 107 110 250 VECTOR sucinta ceca 107 A ari ai hehe senna delete hue acide 110 Vendor supplied models 1 VANO eass E N EA 221 224 278 A E E ES 217 23 281 View Moaea a beta ciate ates 265 View V ATA DIES nando dan 106 Viewers us 210 251 2655213 219 261 501 Vaod asctiiat ae E 143 VOIO reon E E 265 VOW R S alae E S 32 WOW Ra eee tan 141 W WAV CO CS is 1 W aveno lt lat 2217293 Wire Solid buttonuna ieee eects 273 Write Internal Data Files id 299 A Ne Peat Ee et 305 Y Y PAP AIC TCG A A 141 A ties ahareaceenc tin Meats dedi dagen 145 A am ear ier Ge Re EE nL ae eae ne eee 141 E A A AR AE 3
117. NESYS are for use with post processed calculations Note These are advanced functions which are not required my most users If you are not sure if you need to use them then you probably don t COUNT expression For post processed data this function will return the number of data points in the swept data For example if Linear is a linear simulation with 101 frequency points then COUNT Linearl Sch DB S21 is 101 This function is most useful if you want to loop post processed data points with IF THEN GOTO Statements GET string Gets a measurement from a string variable The statements A DB S21 and A GET DB S21 are identical This statement exists so that you can pass a string containing the name of a measurement into a function allowing the function to get the data GETINDEPVALUE exptession index dim returns the independent data point for dimension dim of a post processed expression Expression is the post processed data index is the point number and dim is the independent dimension number to use For normal frequency sweeps dim should be 1 For parameter sweeps with multiple independent sweeps you must use dim to specify whether you want to get frequency dim 1 or the parameter dim 2 or higher for nested parameter sweeps Equation Reference Note If the independent data is frequency GETINDEPVALUE returns the values in Hz not MHz GETVALUE expression index calculates and returns a value of a post processe
118. NG E12 E Shows db angle for all Ej Not available on Smith Chart The Noise Measure measurement is a real function of frequency and is available for 2 port networks only The noise measure is defined in terms of the noise figure NF and maximum available gain GMAX as NMEAS NEF 1 1 1 GMAX The noise measure represents the noise figure for an infinite number of networks in cascade Values Real value versus frequency Simulations Linear Default Format Table MAG Graph MAG Smith Chart none Commonly Used Operators Operator Description Result Type DB NMEAS noise measure in dB Real MAG NMEAS magnitude of the noise measure Real Examples Measurement Result in graph Smith chart Result on table optimization or yield NMEAS MAG NF MAGINF DB NMEAS magnitude of the minimum noise magnitude of the minimum noise measure measure x Not available on Smith Chart Measurements Linear The Noise Figure measurements are real functions of frequency and are available for 2 port networks only The noise figure is defined as the ratio of input signal to noise power ratio SNR to the output signal to noise ratio SNRour NF SNRix SNRour The noise figure is related to the minimum noise figure NFMIN by the expression NF NFMIN Rn Gs Ys Yopr where Ys Gs j Bs Source Admittance Ryn Normalized Noise Resistance The minimum noise figure represents the noise figure wi
119. OCP DBM OCP MAG OCP MAG OCP MAGJ OCP Not available on Smith Chart This measurement is the power of the tone channel used for intermod measurements such as IIP3 OIP3 SFDR etc The Tone Channel Frequency is the frequency of the first adjacent tone to the generated intermods This frequency plus the Channel Measurement Bandwidth make up the Tone Channel The exact location of this channel is specified as a relative offset to the main or primary Channel Frequency for the specified path This primary channel frequency plus the Tone Offset specified in the System Simulation Dialog Box is the Tone Channel Frequency As with all other frequency measurements SPECTRASYS is able to deal with the frequency translation through all mixers In order to make this measurement three signals tones must actually be present at the input port 1 main channel signal 2 first interfering signal tone and 3 second interfering signal tone Furthermore the spacing of the two interfering tones needs to be such that intermods will actually fall into the main or primary channel If these conditions are not met then no intermod power will be measured in the main channel This measurement is simply a Channel Power measurement at the Tone Channel Frequency Values Real value in Watts Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Res
120. Operators DB MAGI RECTI ANG360 RE IM MAGANG MAGANGQ360 1 DBANGT Examples Measurement Result in graph Smith chart Result on table optimization or yield 522 dB Magnitude of 22 dB Magnitude plus angle of S22 QLIS21 Loaded Q of S21 Loaded Q of S21 MAG S21 Linear Magnitude of S21 Linear Magnitude of S21 S Shows dB Magnitude plus angle of all S Parameters RECT S Shows real imaginary parts of all S Parameters GD S21 Group delay of S21 Group delay of S21 Note For port numbers greater that 9 a comma is used to separate port numbers For example on a 12 port device some of the S Parameters would be specified as follows 1 11 12 2 812 11 812 2 147 Simulation 148 This H parameter or hybrid parameter measurements are complex functions of frequency The frequency range and intervals are as specified in the Linear Simulation dialog box The H parameters are only defined for a two port network and are of the form Hy for i j equal 1 2 The equations relating the input voltage V1 and current l1 to the output voltage V2 and current l2 are Vi H11 h Hiz Va L Hal Ha Va Values Complex matrix versus frequency Simulations Linear Default Format Table RECT Graph RE Smith Chart none Commonly Used Operators Operator Description Result Type RECT H11 real imaginary parts Real RE H22 real part Real MAGANG H21 Linear magnitude and angle in range of 180 to 180 Real
121. POWER Viewer section for more information In the normal mode EMPOWER solves for the currents in the metal There is an additional mode where EMPOWER solves for the voltages in the gaps and in lossy metals This mode must be turned on manually by checking Slot type structure when starting an EMPOWER run from GENESYS or by using the VOLTAGE keyword when describing a LAYER in a TPL file In general you should check Slot type structure whenever the metalization layer has more lossless metal than open space This is often the case in a slot type structure such as coplanar waveguide The answer will always be identical but you will save orders of magnitude of memory and simulation time by ensuring that this checkbox is set to the right value Note This setting has no effect on z directed metal viaholes etc which is always calculated as currents There is a caveat when describing lossy problems with this option All non ideal metal must be analyzed so if the metal in your problem is lossy turning on Slot type structure will result in both the air and the metal being analyzed which will have a disastrous effect on memory and time requirements Be sure that your metal layers are set to lossless if you check the slot type structure box 237 Simulation 238 The first part of an EMPOWER run involves taking Fourier Transforms of the grid These transforms will run much faster if the number of cells along the each side of the
122. SCITLATO Ri eel 43 Oscllator Deia 32 Out orDoundS ernea 110 a E T A EA TEE E 106 Output EG UA ONS sousse in 112 P Bala See ROC Seen AE eee A Be See re eee oe 10 A A 259 Pararneter Sweep osicrini aaia 5 1252 101 Parameter Sweep Properties 101 PACA OS 125 141 PATA SIC Sih O Geos eas 1 Partial Dielectric Loading seses 285 Pachan nna aise care eee 241 Pat Pre qUe ea 83 Pato poc rada cdd 85 Pas o o NSRP AT PCTS 82 a AA A ai et ta 288 Perni n e E A 217 278 a A A Creer ore erry eee 217 288 PASE AN Oi Se tase tea Hee thea le 1 PI 110 Bal a cette ee OEE PRO are ene ene REED Pe 261 287 288 A O OO Rie ee eee 303 PEX terte ts and 301 Port inpedanccrt aia 120 303 Por Nom Def A ops hae ce 141 Fron Tye enur neti eaek 241 259 Potts 2 4 205 221 225 245 257 260 261 288 Post processing 107 112 115 141 143 145 146 POS Sia dia 1 a A te Noone na A 106 Preferred Cell Contando 238 Problem Formulati0N oooconnnccconincnonnccananinanoss 288 Provided Device Data aid 120 Q E E E tata E E E EE T 143 R R1303 Radians Mulplera nata 110 A 107 143 PE A O SOR UNE TA 107 a e AAA cand ssneeiectsnnsst 215 Recalculate NOW 2d ii dd 50 Recalculation button diia 50 Record IRGC iaa 122 OS A IS 141 143 Rectangular Caridad 283 284 Rectangular Wav Guides sidra eian 288 O psa eh a eee a aaa 103 Rer oe 2 1 A ny S 241 Rererence Planes ios 245 250 257 Reflection Coefficient eese 52 553 96 39 Reload atea 116 Relat
123. STAR is a linear simulator and because circuits are assumed time invariant element values are not a function of time sub components are uniquely defined by a set of port parameter sets such as two port S parameter data Although ONE TWO THR FOU and NPO ate typically used for active devices they may be used for any devices for which you can compute or measure data For example they could be used to characterize an antenna a circuit with specified group delay data or measured data for a broadband transformer or a pad Data files can be used in GENESYS in two different ways e By adding a Link to a Data File in a simulation This allows measurements to refer directly to the data file without the need to create a design e By using ONE TWO THR FOU or NPO elements in a circuit file or schematic In both cases you must know in advance how many ports the device data represents For transistors this is almost always 2 119 Simulation Link To Data File A Link to Data file allows you to plot data from a device data file without drawing a schematic or creating a netlist To add a data file import 1 Right click the Simulation Data node on the Workspace Window 2 Select Add Link To Data File For information on the Data File Import Setup dialog see the Reference manual For an example see Model Extract WSP Link to Data File Setup To open double click or create a Link to a Data File Data File Import Se
124. Simulation dialog box 93 Simulation System Simulation Parameters x General Paths Calculate Composite Spectrum Options Design To Simulate Sch Measurement Bandwidth Hominal Impedance 50 Ohms Channel Pes MHz Recalculate Now ou must enter the channel bandwidth here before simulation M Automatic Recalculation Sources Cancel Apply Help By clicking on the Edit button of any source the following System Source Parameters dialog box comes up This page is used to enter parameters for each soutce as described below Source Mame EA Input Port fi Include Signal Signal Type Cu N arrow New Custom Source with Phase Noise MiernrEdit Center Frequency Step and Repeat Signal Bandwidth 1e 6 Frequency Offset f MHz Power Average Amplitude Offset fo dE Phase Shit Phase Offset Jo Number of Signals E Number of Simulation Pots Broadband Noise Start Frequency MHz ower 174 dEm Hz Stop Frequency 100 MHz Number of Points jo When enabled for any source on a port broadband noise le used instead of thermal noise at that port Cancel Apply Help Center Frequency This is the center frequency of the source in MHz 94 SPECTRASYS System Bandwidth This parameter is the bandwidth of the source in MHz The lower frequency of the source is the center frequency minus 2 the bandwidth and the upper
125. TRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DBISNF stage noise figure in dB Real MAG SNF numeric value of the stage noise figure Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DBISNF DBISNE DB SNF MAGISNF MAG SNF MAGJ SNF Not available on Smith Chart This measurement is the output 1 dB compression point specified in the element parameters for the particular stage This parameter is currently only available for the SPECTRASYS non linear behavioral models such as amplifiers and mixers For all stages where this parameter is not specified a large default value of 100 dBm is used Values Real value in Watts Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DBMI SOP1DB stage output 1 dB compression point in dBm Real Measurements SPECTRASYS MAG SOP1DB numeric value of the stage output 1 dB compression point Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DBMI SOP1DB DBM SOP1DB DBM SOP1DB MAGJ SOP1DB MAG SOP1DB MAG SOP1DB Not available on Smith Chart This measurement is the output second order intercept specified in the element parameters for the particular stage This parameter is currently only available for the SPEC
126. TRASYS non linear behavioral models such as amplifiers and mixers For all stages where this parameter is not specified a large default value of 100 dBm is used Values Real value in Watts Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DBMI SOIP3 stage output third order intercept in dBm Real MAG SOIP3 numeric value of the stage output third order intercept Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DBM SOIP3 DBMISOIP3 DBM SOIP3 MAG SOIP3 MAG SOIP3 MAG SOIP3 Not available on Smith Chart This measurement is the output third order intercept specified in the element parameters for the particular stage This parameter is currently only available for the SPECTRASYS non linear behavioral models such as amplifiers and mixers For all stages where this parameter is not specified a large default value of 100 dBm is used Values Real value in Watts Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type 189 Simulation 190 DBMI SOIP3 stage output third order intercept in dBm Real MAGJ SOIP3 numeric value of the stage output third order intercept Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DBM SOIP3 DB
127. UT the internal ports and lumped elements can be generated and added automatically EMPOWER Lumped Elements and Internal Ports The circuit below uses automatic port placement Initially the circuit on the left is drawn in SCHEMAX The layout on the right of the figure was then created The footprint for the chip capacitor was automatically placed The lines and EMPorts were then manually added When EMPOWER is invoked internal ports are automatically added so the circuit simulated is virtually identical to the one on the left below and the result is a 4 port data file MYNET 2 EMPOWER then automatically creates a network which is identical to the network shown in the previous section This result is fundamentally the same as the result from MYNET below When the capacitor below is tuned or optimized the networks MYNET and EMPOWER are both updated simultaneously Even if you create a file with a layout only no schematic you can still use automatic port placement Simply put the parts down onto a blank schematic connecting them into a dummy network The parts will now show up in LAYOUT and can be moved as needed ignoring any rubber bands The rubber bands come from the meaningless connections in the dummy network When you display the EMPOWER simulation results it will include the components You do not need to display the results from the schematic Note EMPOWER will create planar ports for lumped elements if
128. WSP Simulations EMPart1 EMPOWER L2 was used This corresponds to the second set of inputs for PART1 You should view the listing file Right click on EMPart1 and look at the port numbers to determine which EMPOWER L file contains the line data you need Note Files with names like WSP Simulations EMPart1 EMPOWER L2 are taken from within the current workspace For a complete explanation of how these files are names see the File Formats section in this manual The substrate must also be specified but only the UNITS parameter is used by the MMTLP8 model A variable was setup LENGTH so that the lengths of line can be tuned in GENESYS simultaneously changing the size of the spiral and thus the inductance very quickly 254 EMPOWER Decomposition d GENESYS Y7 0 Graphl Workspace rez5d E File Edt View Workspace Actions Jools Synthesis Window Help Osa Bejocje o sua a am E E a Designs IE E Part Layout Ea a Part Layout ff SPIRAL Schem iE COMBINE Sche E off INDUCTOR Scl Sl s Simulations Data z Ss EMPartl Par Ej EMPart2 Part2 E E ae Sij Linear 0 to VOC 7 E ra Outputs 5 DBA 521 D8 511 DB S21 DB S11 A rai Substrates Freg MHz Error ve The results from this are shown above Notice that even with only 5 analysis points across the band the interpolation is very good To illustrate this the spiral inductor was re
129. Y and Z current components A segment of microstrip line terminated by a via hole from Swanson 1992 is described in the file VIA WSP The line is 12 mil wide and is terminated by a metal square 24 by 24 mil with a 13 mil diameter circular via hole in the center The substrate height is 15 mil and the relative permitivity is 9 8 The box size is 120 by 120 mil Load this example in GENESYS and run the EMPOWER viewer The first figure below shows the time averaged plot View Menu Switches Value Mode or Value Mode button for additive XY current density distribution The view point is the oblique view with a few minor adjustments The plot shows how the dominant microstrip line mode currents spread across the square metal pad You can see the typical peaks in the current density function in the vicinity of the metal internal corners where the surface current changes flowing directions Toggling to the X and Y components of the current XY X Y Z button you can investigate how the surface currents change direction in different parts of the structure Switching to the Z current visualization mode will show a plot like the second figure below Note that the scale for the Z directed currents is in Amperes and not current density Each current represents a volume current density integrated across the 278 EMPOWER Viewer and Antenna Patterns grid cell They are shown as lines connecting the corresponding geometrical point in the erid plane and the point
130. YZ Down allow the creation of thick metal going up down to the next level or cover 239 Simulation 240 Thick Metal Checking this box forces EMPOWER to model the metal including thickness EMPOWER does this by putting two metal layers close together duplicating the traces on each and connecting them with z directed currents If thick metal is used then Current Direction is ignored Element Z Ports This setting specifies the default direction for automatically created element ports either to the level above or to the level below Generally you should choose the electrically shortest path for this direction EMPOWER External Ports Every EMPOWER circuit must contain at least one port These ports are divided into two major categories external ports which are at a sidewall and internal ports which are inside the box This section will cover only external ports internal ports are discussed in a later section of this manual By now you should be familiar with the placement of external ports EMPorts If not you should follow the first example To briefly review An external port is placed in LAYOUT by selecting EMPort from the toolbar These ports are generally placed on the edge of the box at the end of a line 35 a i o Bas a oe NS oe o O da a a o o o AREE ERE CE Se a o so Oe os This figure shows a comparison between a port in circuit theory and a port in EMPOWER In the circuit theory schematic on the left t
131. You should then see contours like shown above 168 Measurements SPECTRASYS This measurement is the integrated power of the specified adjacent channel All adjacent channels are relative to the main channel identified by the Channel Frequency and Channel Measurement Bandwidth Consequently channels exist above and below the main reference channel frequency The user can specify which side of the main channel the adjacent channel is located on along with the channel number The channel number is relative to the main channel Therefore channel 1 would be the first adjacent channel channel 2 would be the second adjacent channel and so on U Upper Side L Lower Side n Channel Number any integer gt 0 For example ACPL2 is the power of the second adjacent channel below that specified by the channel frequency If CF was 100 MHz and the channel bandwidth was 1 MHz then the main channel would be 99 5 to 100 5 MHz Consequently then ACPL2 would then be the integrated channel power between 97 5 and 98 5 MHz and ACPL1 would be the integrated channel power between 98 5 and 99 5 MHz Note Only the first 2 adjacent channels on either side of the reference channel are listed in the Measurement Wizard However there is no restriction on the Adjacent Channel Number other than it must be non negative and greater than or equal to 1 See This measurement is simply a Channel Power measurement at the Adjacent Channel Frequency
132. a mod eis snlatlomlons ies dutiauarndia coals 36 Lhne Uniliteral Case ela adds Tiiyees 37 E eE e E E E A S OE A E E OE 37 Nose Ci Cle natsia aeae E I EE TOR tia diia 38 SPI AA sec OS 3J DCO ARAS OYES NAAA AA A AE 41 BOAMP OPET S er ds 41 Table Of Contents Harmonte Baltic veritas 43 HARBEC OPHION un lacio 43 TARDES POUD Mentir bs 50 Entero Nonnea Mode stand adaS 51 Typical Harmome Balance Measurements lc 52 COMPE OM O O a a oia 52 SORME Gonveroenca SUS OS 52 Optmizi o Simulation Perrorman es pia oi 53 Jacop Calcula aii aso 53 Oder ecu and T E i E et aati 53 APURI E A te acest das 54 Krylov SUS Pace MEON coca cexeyccscd cast ea E T crease 54 System Modelado 59 COS SAN aena E E E O 55 Dialos BOX 1 Clete spinien an OR 56 System Simulation Paranicters General Tabs 56 System Simulation Parameters Patas Taba stat 57 System Simulation Parameters Calculate Tabiusrrnmasiatada aaa 58 System Simulation Parameters Composite Spectrum Tab 61 System simulation Parameters Options TaD ersen i ida 65 HOw it Works inan aaa a 67 RUAN SNA SUS a acoA Ra oelaaauatald evat tna alas ianteta alate ueiat ear usish eso taaulucaths 67 CAS aie acu tnetia cat tea aaa hash a chun aw eaes donee AL Se cent a 68 COREENE Meee re eee y coer E dd iii va nee er OS amp TI AOS id 73 Ia nr EY Re OY RW RS a ne ORT REE SO ne ER Een Pe eo TT MA OE O E E E E 78 Bondar Canea O E A TEE NA 81 Pata A T A 82 OMS 86 kevet Darrai cea scsc ses ntare E sobiadcbene ant g
133. a slight offset This option can also be selected by pressing End T Current Plot Shows the color coded current patterns for the loaded EMPOWER generated viewer data file The menus and toolbar buttons control how this image is displayed U Color Scale For Current Plot This scale shows the relative current and current density magnitudes based on the color used to draw the plot patterns The EMPOWER far field radiation data describes the electric field patterns in the far zone region radiated from a structure The far zone is defined as the region where 2TR A gt gt 1 where R is the distance from the structure and lambda is the wavelength of the sional exciting the structure Far field radiation patterns are described in the spherical coordinate system where phi is the angle on the xy plane from the positive x axis and theta is the angle from the positive z axis The distance is not specified since it is assumed to be in the far zone Assumptions Made when Generating Far Field Radiation Data Data for radiation in the far field is generated using equations that make simplifying assumptions about the layout of the structure It is therefore necessary to take these assumptions into account and follow them to get accurate solutions e The walls of the box are assumed to be infinitely far away from the structure e Ifa substrate is used it is also assumed to extend infinitely in the lateral dimensions e Fields generated from z di
134. about Smart Noise Point Removal In Bandwidth This is the bandwidth where extra additional noise points can be inserted The center frequency of these noise points is the frequency of each signal This parameter is used when the user wants greater resolution of the noise like through a narrowband Intermediate Frequency IF filter This bandwidth defaults to the channel bandwidth if this parameter is left blank Noise Simulation Tips The more noise points used in the simulation the longer the simulation time will generally be Since each component generates noise the more components in a schematic will also increase the simulation time Better speed performance can be achieved for a large number of components by disabling noise calculations Calculate IIP3 TOD When checked SPECTRASYS will calculate input and output third order intercept points Intercept calculations are not based on cascaded equations but rather 2 tones or even more for the manual mode with a user defined frequency offset will created at the input to the system All intercept and intermod levels will be based on the actual tone levels The cascaded intermod equations make the assumption that the interfering tones are never attenuated Consequently erroneous results will result 60 SPECTRASYS System when modeling and entire receiver since the IF filter will typically attenuate the interfering tones Cascaded intermod equations will give the wrong results for th
135. accuracy of discontinuity analysis Note that despite the theoretical ability to excite and to match any propagating line elgenwave using the surface current sources in the metal plane it does not always work in the discrete models Using a limited number of variables in the source regions it is sometimes impossible to separate different modes completely Moreover the success of the MoSD application depends on the high order modes that could substantially influence the result This is the main drawback of the described MoSD application to planar structures 297 EMPOWER File Descriptions In performing its tasks EMPOWER creates many different types of files An understanding these different files is very helpful in understanding the operation of EMPOWER These files contain the topology of the circuit external port line data generalized S Parameter normalizing impedances output information S Parameter data batch commands Y Parameter data viewer data and backup data Where are these files Starting with Version 7 0 GENESYS uses OLE Structured Storage for its workspace files These files are sometimes called file systems in a file Structured Storage files contain internal directories and files and copying one workspace file copies all internal files contained in it The figure below shows the structure of a typical workspace file Notice that within each simulation all filenames begin with EMPOWER ES Y CABSCoupl
136. ace into the MODEL directory the model will load automatically each time GENESYS is started This is the recommended method to share models with others User Model Example A Self Resonant Capacitor This example describes how to create a model for a self resonant capacitor Note This example assumes that you are familiar with drawing schematics and entering parameters The figure below shows the model used in this example along with its equations J GENESYS 7 5 File Edit View Workspace Actions Tools Schematic Synthesis Window Help 058 O o gt Se SMARA 050 As gt 1IT HA Lumped Linear Nonlinear T Line Coax Microstrip Slabline Stripline Wave ile ES fom a DA Er a Resonant frequency in Radians Second ey ee WO 2 PI F0 1 e6 F ci Equivalent series inductance in nH B L 1e9 C 1 e 12 WO0 2 Line 2 127 Simulation 128 To create this model 1 Create a new workspace by selecting New on the File menu 2 Right click the Designs Models node in the Workspace Window as shown below Workspace Window ea ra DesignsModels is ie e Schl Sche Add Schematic Simulations D at Add Layout Outputs Add Text Nethst Equations Add User Model Schematic substrates Add Link to SPICE Model Optimizations Add Model Single Part field A Notes 3 Select Add User Model Schematic 4 Name the model Self_Resonant_Capacitor Note Spaces are not a
137. add harmonics and intermods as power 72 SPECTRASYS System BE schi Workspace Getting Started 7 PHASE 1 RFAMP_2 Azo ATTN_2 G 12dB Z050 chm L 3d8 MF 3d8 Input SPUTZA gt 1L 2 0103 dB 1S0 30 dB PH3 0 SPLIT2_2 IL 3 0103 dB ISO 30 48 PHASE_2 ATTN_1 RFAMP_1 Co AD lada 6128 Z0 50 ohm 2 NF 3dB Use of a splitter is also a convenient way to create multiple coherent sources The following 4 way splitter creates four coherent sources O SPLITA 1 6 021 dB Bode Intermods amp Harmonics Calculate Intermods and Harmonics This example will help the user understand how SPECTRASYS deals with intermods and how the nonlinear devices handle these intermods The user will also understand the difference between generated conducted and total third order intermod power See the Amplifier section for more information about the internal amplifier model used in SPECTRASYS Calculated Products The following nonlinear second and third order products will be created for each pair of input signals F1 and F2 listed in increasing frequency assuming F2 is greater than F1 73 Simulation 74 F2 Fl 2p F2 F1 EZ 2F2 Fl P dErm H 2F1 3F1 F1 F2 2F1 F2 2F2 2F2 F1 3E2 ae XIB 3 P IP P dE 6dB n 1 IB P 0 347dbB Ib Hy INE a PE Ih Ibh f The relative levels of spectral components for the small signal regime and equal amplitudes of the signal
138. aged values of the currents Ang Displays the phase delay of the current values F Solid Wire Button This button toggles the type of surface plot to display Wire Displays a wireframe version of the current patterns A wireframe is created by drawing the outlines of the EMPOWER erid currents without filling the resulting polygons Solid Displays a solid surface plot of the current patterns This is created by filling the wireframe polygons G Freq GHz This box shows the simulation frequency in GHz for which the current image data is being displayed This box is restricted to frequencies that EMPOWER has created data for The value can be increased by clicking the button see I below and decreased by clicking the button see H below H Decrease Frequency Button EMPOWER Viewer and Antenna Patterns Decreases the current frequency see G above If you are already at the lowest calculated frequency then this button has no effect I Increase Frequency Button Increases the current frequency see G above If you are already at the highest calculated frequency then this button has no effect J Clockwise Button Rotates the current image clockwise in the plane of the screen The center of the viewer image window is always the center of rotation This option can also be selected by pressing Page Down K Counter Clockwise Button Rotates the current image counter clockwise in the plan
139. al Spectrum See the example Getting Started 5 wsp for a good illustration of Desired and Undesired spectrum Noise Spectrum All spectrums created from noise sources in the schematic are placed in the Noise Spectrum and also in the Total Spectrum Intermod Spectrum All spectrums created from intermods between two or more signals are placed in the Intermod Spectrum and also in the Total Spectrum Total Spectrum Every spectrum passing through a node will appear in this spectrum category Level Diagrams A level diagram is a diagram that can display measurements of cascaded stages along a user defined path Each horizontal division of the x axis of the graph represents a stage along the path The first division represents the input to the cascade and the last division represents the output of the cascade The value of the measurements are displayed on the vertical axis The concept of level diagrams has been around for several years RF designers have used level diagrams for decades to architect and design RF systems These diagrams have not appeared in commercial RF simulation software until SPECTRASYS Eagleware s implementation of a level diagram is unique and will help the RF engineer to optimize the RF system performance right from the diagram Level diagrams give the user a quick visual indication of the performance of the entire cascade Node numbers ate placed on the horizontal axis to show
140. alternate method of thinning out Global thinning Can reduce memory requirements under some circumstances Oz Use a smaller line segment 1 times smaller for de embedding calculations Can speed up line analysis IT Output viewer data file in text format PLX Console Window 230 BREMI EMPOWER Log Running Workspace layonly Press Escape to stop the EMPOWER run EMPOWER Planar 3D EM Simulator Version 7 66 lt C gt 1998 99 Eagleware Corp FREQ 11666 MHz gt Mode lt DISC gt ViewtX gt Loss K gt Thintk gt Symmt YZ MIRR gt Estim time 66 66 61 Each frq 66 66 61 Estim RAM 346K se Starting Line Analysis to De embed PORT 1 9566 MHz Zo 44 932 G i28M 938B 11666 MHz Zo 45 646 G i326 651 se Starting Discontinuity Analysis 8666 MHz 11 1 46 lt 295 S21 5 92 lt 2B4 9566 MHz 11 263 lt 1 6 S21 16 2 lt 95 8 The window above 1s shown when EMPOWER is running The objects on the second line ate FREQ The current calculation frequency Mode DISC discontinuity LINE line analysis or LN D both View Checked if viewer data is to be generated Loss Checked if physical loss is being modeled EMPOWER Basics Thin Checked if thinning is enabled Symm Displays the type of symmetry possessed by the circuit being analyzed This option can be XZ YZ Mirror 2 way mirror or 1800 rotational The objects on the third line ate Estim Time The estimated total time to com
141. an then be set to examine the spectrum at any node in the system Since a channel and a schematic path can be defined the user can examine any one of over 30 spectrum integrated measurements along this user defined path on a level diagram SPECTRASYS has many advantages over traditional system simulators e SPECTRASYS is completely integrated into the GENESYS environment and provides the platform that ties all of the synthesis circuit simulation layout electromagnetic simulation and testing together e Any linear component can be placed in the system schematic along with any of over 45 RF behavioral models e Arbitrary topologies and multiple paths are automatically accounted for e The user can view full spectrums at any node in the system e Frequency dependent VSWR interactions between stages are automatically included e All measurements are channel based and are a result of spectrum integration e Level diagrams can display any of over 30 measurements along any user defined path e The origins and paths of all spectral components on every node can be easily identified e Broadband noise is readily analyzed and processed 29 Linear Simulation Linear simulation calculates S parameters and noise parameters of a circuit It is a small sional analysis that assumes that the circuit is operating in the linear region Active devices such as transistors and diodes can be modeled either with S parameters measured or provided
142. ancels the capacitance caused by the end wall as well as correcting other reactances The value of X may be negative and it is frequency dependent The RefShift lines at the outside move the reference planes to the correct location Since the RefShift lines also help to correct for the discontinuity at the box wall their lengths are normally not zero even if the reference shift specified for the port 1s zero The impedance of the RefShift lines is equal to the port line impedance so only the phase is shifted by the addition of these lines The magnitude of the reflection coefficients is not affected The parameters for deembedding are calculated prior to the analysis of the circuit EMPOWER does this automatically by analyzing two different length lines at each frequency for each port used solving for the reactance and the base RefShift value Note Deembedding requires an additional line analysis mode at the start of the run so runs using deembedding can take substantially longer This is especially true if the lines at the ports are wide since a wide line is simulated across the entire length of the box However line analysis is always symmetrical and may be symmetrical in two planes if the port lines are placed exactly in the middle of the box EMPOWER also caches the line analysis results so if the box and port lines are not changed between runs previous data will be used The data for these lines are stored internally in the Workspace
143. apostrophe Any part of a line can be a comment and everything after the apostrophe is ignored The comment line format is Comment Example This line will be ignored The label statement identifies a section of the EQUATION window for use in GOTO or IF THEN GOTO statements After the GOTO is executed the statement following LABEL is the next statement executed If LABEL is the last statement in the window the equations end after the GOTO The format is LABEL Labelname This statement causes the EQUATION interpreter to jump in its calculations to the statement following the corresponding LABEL statement The format of the GOTO statement is GOTO Labelname This statement is perhaps the most powerful one included in GENESYS This statement causes the following steps to occur 1 The value of the expression is calculated Any true comparison results in a value of 1 For example the expression 1 gt 0 gives a value of 1 while the expression 0 gt 1 gives a value of zero 2 The value obtained in step one is compared to zero If the value is not zero then the interpreter performs the statement specified The format of the IF statement is IF expression THEN statement Example Equation Reference IF Q gt 1000 THEN GOTO HIGHQ RVal 100 GOTO DONE LABEL HIGHQ RVal 500 LABEL DONE Warning You cannot use IF THEN with post processed variables Use the IFF and IFTRUE functions instead Since GENESYS uses approximat
144. ar Step Size List of Values alear List 15 Right click on the Outputs node in the Workspace window and select Add rectangular graph Name the graph DC Curves 16 Enter Default Simulation Data or Equations Ib Sweep DC Curves Measurement tic Unclick Auto scale in the Left Y axis Enter Min 0 Max 1 5e 3 of Divisions 5 Click OK Measurement HC means current I at probe IC Graph Properties E Default Simulation D ata or Equations bSweepDCCuves EY A remeras e Left Y Axis FT Auto Scale Mir Right Y Axis IV Auto Scale Min f X Axis IV Auto Scale F Log Scale Cancel in fico 18 Min 25 Measurement Wizard fises P Fidde 18 t ES Max 1 5e 3 Max Max di Equation Wizard Divisions 5 Divisions fi 0 Divisions 10 2 Advanced Properties E nter the name of a parameter to graph or press a wizard button to guide you through the process of creating a measurement Simulation 17 Click the Calculator icon in the toolbar and the graph displays DC curves for the transistor as shown below These can be compared to manufacturers data to verify correct data entry or model accuracy JP GENESYS 7 5 DC Curves Workspace I Curves fd File Edit View Workspace Actions Tools Synthesis Window Help laj xj Dee t Be oela p Aaaa ar E COE 5 E E Designs Models poo hu Ey DC Curves Sc
145. ar tools on the market EMPOWER is based on the method of lines MoL and comprises a set of numerical techniques designed to speed up calculations while increasing accuracy of computations Incorporation of geometrical symmetries including rotational reduction of problem complexity using thinning out and linear re expansion procedures and multimode deembedding by the simultaneous diagonalization method are outlined here This theory section is for EMPOWER users familiar with numerical electromagnetics foundations We have added this material because MoL is less well known than the method of moments or the finite difference method MoL can be represented as a simple combination of both method of moments and finite difference method Thus we have skipped common parts and given our attention to the original parts of the algorithm More details on particular algorithm parts accuracy and convergence investigation results can be found in publications listed in the References section in the EMPOWER Engine Theory and Algorithms section Basically the theory behind the simulator can be reduced to the following An initial 3D problem in a layered medium is reduced to a 2D problem through a partial discretisation of the Maxwell s equations and its solution for a homogeneous layer in a grid spectral domain The resultant matrix relating local grid currents and voltages is reduced to an immitance matrix relating integral currents and voltages in ports To ext
146. arameters can be used for any purpose including graphing tabular display optimization yield and post processing The following table shows the available Measurements Where 7 and j are shown in the chart port numbers can be used to specify a port Some parameters such as Az use only one port e g Al or VSWR2 Or on a tabular output the ports can be omitted ie S or Y and measurements for all ports will be given Tip All available measurements and their operators for a given circuit or sub circuit with their appropriate syntax are shown in the measurement wizard To bring up the measurement wizard select measurement wizard from the graph properties dialog box Note The section in this manual on S Parameters contains detailed information about many of these parameters Meas Si Hi YPi ZPij ZINz YINz ZPORTz VSWRz Ej Ny GMAX NF NMEAS Description S Parameters H Parameters Y Parameters Z Parameters Impedance at port 7 with network terminations in place Admittance at port with network terminations in place Reference Impedance at port z VSWR at port z Voltage gain from port 7 to port 7 with network terminations in place Noise correlation matrix parameters Maximum available gain Noise figure Noise measute Default Operator DBANG RECT RECT RECT RECT RECT RECT Linear real DBANG RECT dB real dB real Linear real Shown on Smith Chart Si Su
147. as used The base of the solution is a layer admittance matrix in the grid spectral domain This matrix relates the grid analogues of the tangential electric and magnetic field components at opposite surfaces of the layer z directed currents and integrals of z directed grid electric field along the z directed current inside the layer All of these are in the basis of the grid eigenwaves thus we have a set of independent matrices for each pair of grid eigenwaves Uniting those matrices for all layers in a structure gives a grid spectral GGF representation The construction procedure is completely automated for arbitrarily layered configurations This technique is similar to the impedance approach in the spectral domain Uwano Itoh 1989 The grid spectral GGF representation was also called a GGF eigenvalue vector but that term is not quite correct The dimension of the vector is about 3 L M if there is only one signal layer All we need now to get the GGF matrix in the initial space is to perform a backward transformation of the GGF eigenvalue vector from the grid spectral domain to the spatial domain To do it an auxiliary array called general sums array is introduced The dimension of the general sums array is also about 3 L M Each element of the GGF matrix can be obtained as a sum of four elements of the general sums array The general sums array depends only on the box and media structure and the grid cell size Its elements are calculated via the
148. atch topology listing and S Parameter files Note Word processors can also edit text files however they will store binary formatting information in the file unless explicitly told not to Save as Text so we do not recommend their use for editing text files In contrast binary files are not human readable They contain information encoded into the numbers which make up the file which are ultimately turned into ones and zeros thus the name binary Unlike text files binary files are not universal and should only be edited by a program designed for the particular type of binary file you are using Editing a binary file in a regular word processor or text editor will undoubtedly destroy it Some binary files used by EMPOWER and GENESYS are workspace line and Y Parameter files You can normally tell the kind of file you have by looking at its extension the part of the name after the last period Some commonly used extensions include EXE executable TXT text and HLP help Each kind of file used by EMPOWER has its own unique extension These extensions are shown here Each of these types will be discussed individually in the following sections Note Unfortunately Windows can be setup to hide files extensions as well as actual files from the user We would recommend that you turn off this feature Double click on My Computer Select Options from the View menu Click the Viewer tab Click Show all files
149. ated by the current stage during the IM3 analysis pass All Intermod power is integrated across the main channel for the specified path This measurement will include intermod power from all paths and all sources at the prior node as well as the current node if those intermods fall within the channel In equation form the conducted third order intermod power ts TIM3P n integration of the total intermod spectrum at stage n across the main channel Using this measurement in conjunction with the Conducted Third Order Intermod Power and the Generated Third Order Intermod Power the user can quickly identify the weak intermod link in the cascaded chain and will guide the user in maximizing the Spurious Free Dynamic Range Note The Calculate IIP3 TOD checkbox must be checked and properly configured in order to make this measurement See the Calculate IIP3 TOD section for information on how to configure these tests In the Calculate WP3 TOD Manual Mode since a dedicated IM3 analysis is not created and the normal analysis is also the IM3 analysis pass Remember intermod bandwidth is a function of the governing intermod equation For example if the intermod equation is 2F1 F2 then the intermod bandwidth would be 2BW1 BW2 Note Bandwidths never subtract and will always add The channel bandwidth must be set wide enough to include the entire bandwidth of the intermod to achieve the expected results The Automatic Intermod Mode will s
150. ation modes X Y or Z are more accurate because the values displayed correspond directly to the values calculated by EMPOWER no interpolation is necessary for these modes The absolute value of the current density is currently displayed Switch to the Real mode using the menu View Menu Switches Absolute Value Display and select Real mode Animation should be turned on also Animation camera button A snapshot of the plot is shown below The Real mode displays both current density values and direction Current flows in the positive X direction if the displayed values are above the metal layer the color coded axis direction The current flows in the opposite direction if the displayed values are below the metal plane empower Viewer Y6 5 LOL File View x amp Real Solid Freq GHap 15 1a lala s 4a 2 Top Front Side Oblique 0 Amm EMPOWER Viewer and Antenna Patterns To obtain even additional insight the phase of the signal along the line may be displayed Stay in X component mode turn off animation and switch to the Angle mode by clicking the Display Option button until it reads Ang You may view the wireframe mode by clicking the Wire Solid button until it reads Wire At the initial time t 0 and with a matching rotation you will a display similar to the one below It displays delay of the current densities along the structure in terms of a complex vector rotation angle 360
151. ations GENESYS supports four different way to enter nonlinear models e Direct Schematic Entry e Single Part Model e Nonlinear Model Library e SPICE Link The simple way is to enter a nonlinear model is through direct schematic entry You place a nonlinear device such as an NPN transistor from the schematic tool bar Then double click the device and type in the device parameters The advantage of this technique is that it is simple The disadvantage is that it is not as easy to reuse the device in another design Another way to enter a nonlinear model is to create a single part model This is similar to using a model statement in other simulators See the Designs Single Part Model section in this User s Guide for details A third way to enter nonlinear models is to choose one from the supplied library of parts To do this just enter the base nonlinear model that you would like for example a PNP then change the model to the desired part using the Model button on the element parameter dialog The final way to enter a nonlinear part is to link the model to a SPICE netlist GENESYS can read SPICE 3 compatible netlists extracting models and subcircuits Most vendors supply nonlinear models including package parasitics in the form of SPICE netlists One advantage of SPICE links is that complex models can be included very easily in the simulation The chance of error in entering numbers is reduced The disadvantage of the link is that
152. ations Linear Default Format Table center MAG ANGI radius Linear Graph None Smith Chart Circle Commonly Used Operators None Examples Measurement Result in graph Smith chart Result on table optimization or yield GA available gain circles center MAG ANGI radius Linear GP power gain circles center MAG ANGI radius Linear Available on Smith Chart and Table only A unilateral gain circle at port 1 is a locus of source impedances for a given transducer power gain below the optimum gain This locus is plotted on a Smith chart and is only available for 2 port networks The center of the circle is the point of maximum gain Circles are displayed for gains of 0 1 2 3 4 5 and 6 dB less than the optimal gain Similarly the unilateral gain circle at port 2 is a locus of load impedances for a given transducer power gain below the optimum gain The transducer power gain G is defined as G power deliver to load power available from source For the unilateral transducer gain S12 is set to zero Note See the section on S Parameters for a detailed discussion of Gain Circles Values Complex values versus frequency Simulations Linear Default Format Table center MAG ANGI radius Linear Graph none Smith Chart Circles Commonly Used Operators None Examples Measurement Result in graph Smith chart Result on table optimization or yield GU1 unilateral gain circle at port 1 center MA
153. ave at one input The excitation conditions are passed to EMPOWER in the command line when running EMPOWER text files When EMPOWER is launched from GENESYS the excitation conditions are automatically defined from the EMPOWER Setup dialog box when the Generate Viewer Data check box is active If Generate Viewer Data is selected the default incident wave is the first eigenwave of the first input The input number can be changed in the Port number to excite box of the EMPOWER Setup 279 Simulation 280 dialog and the input mode number can be changed in the Port mode to excite box The control information about what input and what mode are actually excited in the structure is printed out in the listing file see PPLT Input _ mode ____ will be incident in the listing file An output binary file with the extension EMV is created by EMPOWER to pass data to the viewer program In a GENESYS Workspace the internal name of this file is EMPOWER EMV An optional self documented ASCII data file with extension PLX can also be written for import into other programs To understand the viewer a review of EMPOWER input and mode representations 1s helpful A circuit can have external and or internal inputs External inputs are transformed to eigenmode space de embedded and normalized to characteristic impedances of eigenmodes They could be one mode or multimode modally coupled and the incident wave for these inputs can be one of the input e
154. ave load pull data files Contours Workspace Load Pull Contours Example ee oi xj contours HE datapoints This example File Open Example Load Pull Contours Example wsp loads a Focus Microwaves data file The file contains several columns of amplifier measured data In the plot the Gain column from the data file is used to plot load pull contours from the two Equations shown below contours CONTOUR GAIN 20 30 1 0 2 2 2 2 datapoints PLOTPOINTS GAIN The first equation CONTOUR generates the contours based on the parameters passed to the function See Built In Functions for a description of these functions and their parameters GENESYS supports both Maury Microwave and Focus Microwaves data files 167 Simulation To create a new file using load pull contours 1 From a new GENESYS file right click Simulations on the tree and select Link to Data file 2 After choosing a name select the appropriate file type Maury or Focus and browse for or enter the file name Click OK to close this box Add a Smith Chart by right clicking Outputs After choosing a name click measurement wizard Select the load pull data simulation from the first dialog oS Se A From the second measurement wizard box select Contours or Plotpoints from the first column Select the data to plot from the second column Click OK to close the measurement wizard box and click OK to close the Smith Chart properties box
155. ayouts 8 Press OK to close the Model Properties dialog 9 Draw the schematic as shown in the figure below Mn 0 C1 L L nH C C pF 10 The inductor Q can be left blank which defaults the value to 1 million The capacitor Q should be set to Q which is one of the model parameters entered into the Model Properties dialog in step 5 11 Right click on the model in the Workspace Window as shown below 129 Simulation Workspace Window iqne Models fame cel Resonant Capacitor User Model Schematic Simulations D ata Rename 5 Outputs 42 Equations 23 Substrates Properties Schematic Properties Edit Model Equations Delete This Design 12 Choose Edit Model Equations 13 Enter the equations as shown below BB Self_Resonant_Capacitor Model Equations Workspace Self Resonance Miel ES Resonant frequency in Radians Second YWO 2 PPFO 1e6 Equivalent series inductance in nH L 1e9 C e 1 2 7 0 2 ne 14 This completes the model creation Choose Save from the File menu to update the model file Next let s create a schematic using the new model 15 Choose New from the File menu 16 Draw a schematic consisting of only an input a series capacitor and an output as shown below don t set any parameters yet 17 Double click the capacitor symbol to display its Properties dialog 18 Click the Model button to open the Change Model dialog 1
156. be displayed at 8000 9500 and 11000 MHz For a complete description of rectangular graphs see the GENESYS User s Guide The GENESYS display below shows the EMPOWER tun with 3 sample points 208 EMPOWER Operation BE Graphi Workspace layonly Ml ES a SENN HRS pea 01 0000 0 0 DOI 0 A oC ere Fs AA OSA eN ju a CJ eN a Fred MHz DA 21 DB E11 In this response the notch frequency appears to occur exactly at 9 5 GHz Or does it Let s add some frequency points to the EMPOWER simulation To re simulate adding more points 1 Double click EM1 under Simulations Data in the Workspace Window 2 Change the Number of Points prompt in the Electromagnetic Simulation Frequencies to 11 3 Click the Recalculate Now button 4 Close the EMPOWER log click on the X in the upper right corner of the window This will add to the previous EMPOWER simulation so that we have 11 instead of 3 data points EMPOWER will intelligently recalculate only the additional points The figure below shows the simulation with 11 EMPOWER data points The notch frequency now appeats to be at 9 2 GHz Let s add the full 31 points to the EMPOWER simulation to ensure that we get the actual notch frequency Repeat the previous steps to change the number of EMPOWER points to 31 and recalculate 209 Simulation BE Graphi Workspace layonly Miel ES Tm d D a CJ eN D a 9500 Fr
157. be used with equations TUNEBP EQUATIONS Y shows variable Y from the global equations of workspace TUNEBP Inline equations can also be used anywhere a measurement can be used Start the measurement with to indicate an inline equation For example MAG V1 MAG V2 will use the difference of V1 and V2 Notice that as in the global equations the periods and the operators MAGIJ are required for inline equations This measurement is actually equivalent to the following equations USING MeasurementContext TEMP MAG V1 MAG V2 and then requesting the measurement EQUATIONS TEMP where MeasurementContext is the Default Simulation Data specified in the measurement dialog Measurements Linear This S parameter or scattering parameter measurements are complex functions of frequency The frequency range and intervals are as specified in the Linear Simulation dialog box The s parameters assume a 50 ohm reference impedance unless otherwise specified The s parameters for an n port network are of the form Sj fori j equal 1 2 n Details on the S parameters and their application are found in Section x x of this Manual Values Complex matrix versus frequency Simulations Linear EMPOWER Default Format Table dB angle Graph dB Smith Chart dB angle Commonly Used Operators Operator Description Result Type ANG S11 Angle in range 180 to 180 degrees Real GD S22 Group Delay Real QLIS21 Loaded Q Real Other
158. box A port number 7 is used to identify the port ZPORT is the reference impedance for port z Values Complex value versus frequency Simulations Linear Default Format Table RECT Graph RE Smith Chart none Commonly Used Operators Operator Description Result Type RECT ZPORT1 real imaginary parts Real RE ZPORT2 real part Real MAGANG ZPORT3 Linear magnitude and angle in range of 180 to 180 Real Other Operators MAGI ANGI ANG360 IM MAGANG360 Examples Measurement Result in graph Smith chart Result on table optimization or yield ZPORT2 RE ZPOR T2 RECT ZPOR T2 RECTI ZPORT Shows real imaginaty parts for all ports MAG ZPORT1 Linear Magnitude of ZPORT2 Linear Magnitude of ZPORT1 ZPORT Shows real imaginary parts of all ports Not available on Smith Chart 161 Measurements Nonlinear This power measurement is the RMS power delivered at the port The port is identified by a port designator number Values Real value in specified units Simulations Nonlinear dc analysis Default Format Table DBM Graph DBM Smith Chart none Commonly Used Operators Operator Description Result Type DBM P1 RMS power at port 1 Real Other Operators DB MAGI ANG ANG360 REI IM Examples Measurement Result in graph Smith chart Result on table optimization or yield P1 DBM P1 RMS power delivered to port DBM P1 1 Not available on Smith Chart This current measur
159. calculated with 10 points below You can see quite good agreement between the two To test the validity of the decompositional analysis the entire spiral was analyzed and the results are given in the second figure below This full analysis took hours on a 266MHz Pentium II and if the lengths of the lines in the spiral are changed it must be rerun 255 Simulation l z Beare Ao HE Part Layout i 3 Part Layout 18 SPIRAL Schem COMBINE So B INDUCTOR Sel JE a 8 Simulations Data lio a EMPart Part DB S21 DB 511 1 a si Lineari 0 to 10C a ra Outputs 2 JE AR Graphi al sT Equations fi Bey Substrates F Sis ai _ m A A L1 MRIN1 L2 MRIN1 y UTN ANA T ALT AL NIP aot tet tT NIT TT TT AY IP A AHH a DEIS 21 7000 10000 3 40433 1 33748 3 40433 1 33748 3000 8 97009 8 97009 0 40224 0 40224 256 6 14 4258 0 Pa lp PEAD RIA Y pl CI TT TE tt Fees MAME L3 MRIN1 W_MRIN1 2 S MRIN1 2 LAIND3 4 MAA tt HOANT A AT AN Pt TAL EAL A 7 ae v SERRE Pt tet Ee yy Pi tt tT EE Et PT ETT Ee DB S11 1e 0 3000 7000 10000 0 746666 354981 10 1519 EMPOWER Decomposition A current limitation of decomposition is that losses are not taken into account in multi mode transmission line sections or in reference plane shifts For the spiral inductor this means that the losses as calculated are accurate for the nominal dimensions but any modificati
160. can be increased to large values to see if that is the cause The user can then start decreasing the isolation of the interested components until the desired response is achieved Maximum Number of Spectrums to Generate As a last resort you can limit the number of spectrums that will be generated The number of spectrums generated at any time is shown in the simulation status window while SPECTRASYS is running A typical number to force a limit to is 100000 See the Options Tab for more information Ignore Spectrum As mentioned previously SPECTRASYS will continue to process new spectrums until no additional spectrums have been calculated However in the case where a loop exists spectrums will continue to be created around the loop until the Ignore Spectrum Below threshold is reached at which time spectrums are not calculated below this threshold The higher this threshold the fewer the number of calculated spectrums In order to minimize the simulation time the user should set this threshold to calculate the least number of spectrums which will accurately represent the output For example if the user is not interested in seeing anything below 100 dBm and simulation speed is an issue then setting the threshold to 100 dBm will improve the simulation speed Linear Elements SPECTRASYS System The mote nodes in the system schematic the more spectrums that will be created and propagated This spectrum creation and propagation takes tim
161. cept the default name by clicking OK 10 Click the Annotate checkbox and press OK to show DC voltages on the schematic 11 Right click on Simulations Data again and this time select Add Parameter Sweep Name the sweep Vc Sweep 12 Enter the following values as shown below Simulation to Sweep DC1 Variable to Sweep V Vc Type of Sweep Linear Number of Points Start value 0 Stop value 3 Number of Points 20 Click OK Parameter Sweep Properties E Simulation to Sweep pct OK Cancel Variable to Sweep vve h Help Recalculate Mow Automatic Recalculation Factory Defaults ile Type OF Sweep Linear Number of Points E C Log Points Decade Sweep Range Start Value Jo Stop value 3 Linear Step Size List of Values alear List Walkthrough DC Linear HARBEC 13 Add another parameter sweep for the base current sweep and name it Ib Sweep 14 Enter the following values as shown below Simulation to Sweep Vc Sweep Variable to Sweep IDC IB Type of Sweep Linear Number of Points Start Value 2E 6 Stop Value 10e 6 Number of points 5 Click OK Parameter Sweep Properties E Simulation to Sweep ve Sweep Ok Variable to Sweep 1c 16 bd Help Automatic Recalculation Sweep Range Type OF Sweep Linear Number of Points 5 C Log Points Decade e Start Value Stop Yalue 10e 6 Line
162. ces individually drawing only the part that will be simulated in each piece In this case each individual layout will look like the parts shown above Or e Create a complete layout of the entire problem first Then make the box smaller so that only the desired piece is simulated This is the method we will use for the spiral We have created a layout of the entire spiral inductor as a starting point EAGLE EXAMPLES DECOMP FULL WSP This file was created by starting with an MRIND element so that the layout was created mostly automatically The only addition was the extra leneth leading to port 1 and the EMPorts Notice that the reference plane for port 1 is shifted to the actual start point of the spiral model Port 2 is an internal port This circuit can be analyzed directly but it requires minutes per frequency point and 37 megabytes of RAM This file was then saved as COMBINE WSP The box was shrunk and the circuit was moved so that only the bottom left quarter of the circuit is in the box The number on the internal port on the end of the spiral was changed to 10 Ports 2 5 on the right and 6 9 were added Since these ports are in the middle of a line instead of on the end their width must be set manually Also the reference planes on the ports were shifted in The resulting layout for the first piece is shown below 251 Simulation EMPOWER was run for Part1 The settings are as shown below Nove that only 5
163. channel bandwidth must be set wide enough to include the entire bandwidth of the intermod to achieve the expected results The Automatic Intermod Mode will set the bandwidth appropriately Values Real value in Watts Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DBM CIM3P conducted third order intermod power in dBm Real MAG CIM3P magnitude of the conducted third order intermod power in Watts Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DBM CIM3P DBM CIM3P DBM CIM3P MAG CIM3P MAG CIM3P MAG CIM3P 193 Simulation 194 Not available on Smith Chart This measurement is the generated intermod power in the main channel created at the output of the current stage during the IM3 analysis pass In equation form the generated third order intermod power is GIM3P n integration of the intermods generated at stage n across the channel bandwidth Using this measurement in conjunction with the Conducted Third Order Intermod Power CIM3P and the Total Third Order Intermod Power TIM3P the user can quickly identify the weak intermod link in the cascaded chain and will guide the user in maximizing the Spurious Free Dynamic Range SFDR Note The Calculate IIP3 TOD checkbox must be checked and properly configured in order to make this measurement See the Ca
164. cified if any each time that the model is used You can name and give descriptions for each of parameters A model can be created from any existing schematic or from scratch In addition the user can create a new symbol for this model which will aid in distinguishing the new model from other schematic elements See the section on symbols for details Note You must have purchased SCHEMAX to create and save a schematic model If you have not you may create a text model definition using the process described later in this section There are 2 ways to create a new model 1 Without an existing schematic 2 From an existing schematic of the model Creating A Model Without An Existing Schematic With the Workspace Window 1 Right click on the Workspace Window Designs node as shown in the figure below 2 Click Add User Model Schematic 3 Name the new model Continue with step 5 in the Model Example below 125 Simulation 126 Workspace Window a E Des E Simulations L at Add Layout igns Models l Schl Sche Add Schematic Outputs Add Text Nethst he Add User Model Schematic Add Link to SPICE Model Add Model Single Part Substrates Optimizations field With the Design Manager 1 Open the Design Manager by choosing Designs Models on the Workspace menu 2 Click the New button 3 Select Add User Model Schematic 4 Name the new model Continue with step
165. cite the odd mode as an example select Generate viewer data and enter 2 in the Mode Number to Excite box of the EMPOWER properties dialog Run the viewer A snapshot of the calculated current density function is shown here All settings except two are the same as in the previous example The initial view was set to the side view View Menu Side or Side 277 Simulation button and the polygon view was set to wireframe View Menu Switches Wireframe or Solid Wire button empower Viewer Y6 5 Mim ES File View xy 85 Real Wire Freq Ga 1a lalefl oft4a Top Front Side Oblique The plot confirms that this is an odd mode and shows the typical current density distribution If currents on the left strip flows in the forward direction the currents on the right strip flow in the backward direction and the center strip currents flow in opposite directions at the opposite strip sides For a dynamic view turn on the animation and rotate the plot for a better view of the propagating wave To calculate the viewer data for the other eigenwaves run EMPOWER and the viewer twice more with Mode Number to excite set to 1 and 3 Note that newly calculated data will overwrite the previous ones To avoid this and to keep viewer data for all excitation experiments you need to save a copy of the existing workspace LNMIT3 WSP in this case before the next run The last visualization example shows a structure with non zero X
166. ctral components can be ignored below a user specified level In order to view a composite spectrum plot the user must select the System Simulation and Composite in the Default Simulation Data or Equations combo box of the rectangular graph properties i e System1 Composite The user must then specify whether they want to display a voltage or a power measurement and the node number i e P2 power at node 2 For example a simple receiver shown below will have the antenna signal propagate forward through the receiver front end then through the mixer and the IF chain However after the LO arrives at the mixer it will propagate backwards through the receiver front end to arrive at the antenna input In addition this LO signal will also propagate forward through the IF chain If we were to examine the receiver input on a spectrum analyzer we would see both the input signal from the antenna as well as the LO leakage On the spectrum analyzer we would see both of these signals However we know that they are traveling in different directions At the antenna input node we know that the received signal is traveling toward the IF chain and the LO leakage is traveling away from the IF chain SPECTRASYS System AS schi Workspace composite spectrum Receiver Example RFAMP_1 G 20 dB MIXERP_1 NF 5 dB CL 8 dB OP1D8 10 dm ATTN SUhi 0 ATTN_3 OPSAT 13 dem La2dB L s7d m L 2dB OIP3 20 dBm RF Input 1 2 a
167. ctral components above the given threshold This parameter is mainly used to reduce clutter on the graph such as the case when lots of spectral components appear on the same graph NOTE This option must be selected in order to view the origination and identification of specttal components See the Identifying Spectral Origin section for more information Show Totals Shows a trace representing the total power traveling for each direction of travel through a node For example if three elements were connected at a particular node then power would be flowing in three different directions A unique color would represent each trace Show Signals Shows a trace for each intentional signal source that was applied to an input or output port Show Intermods and Harmonics Shows a trace for each intermod and harmonic spectral component Show Noise Shows a trace for each noise component Enable Analyzer Mode This checkbox enables the analyzer mode and its settings This mode can help the engineer visualize what the simulated spectrum would look like on a common spectrum analyzer The analyzer mode has been added to allow the user to 62 SPECTRASYS System correlate the simulation data with spectrum analyzer data measured in the lab This mode affects only the graphed results and in nowise will affect the integrated measurements Resolution Bandwidth RBW The analyzer mode can be thought of just like a spectrum analyzer that has a
168. d expression This allows you to get the value of an expression at a particular data point index This function is most useful in combination with the COUNT function for looping over values Most users should not use this function preferring the GETVALUEAT function instead Note that this function causes immediate calculation of the value and the value it returns is not swept it is the actual value of a particular data point real or imaginary Advanced note If the independent data is multi dimensional then index can contain an array specifying the index for each dimension GETVALUEAT expression indep calculates and returns a value of a post processed expression at a given independent value For example this allows you to get the value of an expression at a particular frequency such as Q GETVALUEAT QL S21 1e9 which gets the loaded Q of S21 at 1 GHz If no data has been calculated at 1 GHz the data will be interpolated or extrapolated as needed While this function is somewhat slower than GETVALUE it is much easier to use because you do not have to know the index of the point you want Note that this function causes immediate calculation of the value and the value it returns is not swept it is the actual value of a particular data point real or imaginary Advanced note This function only works on 2 dimensional data X vs Y Note If the independent data is frequency GETVALUEAT requires values in Hz not MHz The equation wizar
169. d split coupled etc it will be coherent with itself if the divided paths are added back together For example assume a signal source drives a 2 way splitter before being amplified by two parallel amplifiers which are then combined back together as shown below Since the signal source appeared on the common node of the 2 way splitter each of the splitter output would contain part of the coherent signal 3 Harmonics and intermods generated in different devices are never considered coherent For example in the figure below any harmonics or intermods generated in RFAMP_1 are not considered coherent with harmonics or intermods generated in RFAMP_2 For example itt is our experience that more commonly a small change in the input levels phase modulation or components will cause the harmonics intermods to be completely non coherent in the two amplifiers and this will not cancel out While it is true that for the simple sinusoidal case they might cancel for a more complex signal they may not Also in a real circuit the phase shifters below represent normally represent different time shifts at different frequencies If you have a modulated signal and you shift different frequencies at the input to the amplifier by different amounts of time then both amplifiers see a very different time domain signal and the harmonics they generate will be different and will appear random in nature For this reason and others we have chosen to always
170. d 2 above you could not use a 3 mode port because the ports would be in the order 2 1 3 along the sidewall Running the circuit above in EMPOWER will give 6 port data as would be expected by glancing at the picture However the fourth port is the only normal single mode port In the data file the first three ports of data are in mode space and the last two ports of data are in mode space For example in the data file e S41 represents the transmission of energy from mode 1 of multi mode port 1 2 3 to port 4 e 25 represents the transmission of energy from mode 1 of multi mode port 5 6 to mode 2 of multi mode port 1 2 3 e S66 represents the reflection of energy in mode 2 of multi mode port 5 6 Multimode data should be carefully connected Multimode ports should be connected only to other identical multi mode port or line configuration same box line widths spacings etc Otherwise the connection is non physical and the results are meaningless See the Spiral Inductor example in the Decomposition section for more information on the use of Multimode lines EMPOWER External Ports Setup Modes E These boxes are for modal use only For normal ports clear all boxes A 1 Iw E E empowe F F Ports 5 3 OF Cancel When normal circuit theory analysis is performed the ports are often terminated with a standard impedance such as 50 or 75 ohms However EMPOWER will give much more accurate results if yo
171. d increase the gain of the overall system if reflections toward the source were reduced Shown below is a two port network with lossless matching networks inserted between the network and the source and load GMAX and MSG When the input and output networks are simultaneously designed for maximum gain there is no reflection at the source or load The maximum transducer power gain Gmax 18 given by Gmax S21 S12 K sqrt K2 1 The maximum stable gain MSG is defined as Gmax with K 1 Therefore MSG S21 S12 A GENESYS plot of GMAX shows Gmax when K gt 1 and MSG when K lt 1 Linear Simulation Again acheiving this maximum gain requires that the input network is designed such that Rs is the complex conjugate of S11 and Ry is the complex conjugate of S22 GENESYS returns the required reflection coefficients impedance and admittance for the input and output networks as GM1 GM2 ZM1 ZM2 YM1 and YM2 respectively The Unilateral Case Historically to simplify the complex equation for Gt in the previous section on matching S12 was set to zero At higher frequencies where the device S12 is typically larger this assumption is less valid The assumption simplifies manual and graphical design but is unnecessary in modern computer assisted design The assumption also allows factoring the above equation into terms that provide insight into the design process If 12 0 then Gtu S2112 1 R30 R113 1 SuuRs
172. d is a valuable tool that can help the user create the proper syntax for g P PORE Sa post processed equations The equation wizard can be accessed in one of two locations 1 from the graph properties dialog box and 2 from the main menu under the Tools submenu Note The equation window must be the active window before the Equation Measurement Wizard menu selection will become active Graphing an Equation The equation wizard can be used to create an equation that can be plotted on graph See graph properties and the Equation Wizard dialog box for more information on graphing equations Equations in the Equations Section While typing equations in the Equations Section of the workspace the Equation Measurement Wizard can be accessed from the Tools submenu located in the main menu Selecting Equation Measurement Wizard will bring up the Measurement Wizard allowing the user to select the workspace and the desired simulation Another 115 Simulation 116 Measurement Wizard dialog box will then appear where the user will be able to select the desired function and operator Note Equations will be inserted into the Equations Section at the current location of the cursor The NOT AND OR operators are called logical operators They can be used to combine relational tests such as A lt 5 amp B gt 6 They can also be used in binary math as described below Note The information below is for advanced users and assume
173. d variable repeating another simulation for each adjustment For example to see how the response of a circuit changes when a capacitor is adjusted you can add a Parameter sweep which sweeps the linear or electromagnetic simulation while adjusting the capacitor value You can then view the results on a 3 D graph To add a parameter sweep 1 Right click the Simulation Data node on the Workspace Window 2 Select Add Parameter Sweep 3 Add a Table or 3 D graph to display the results For advanced applications you can nest Parameter sweeps creating 4 D 5 D or higher data This data can then be viewed on a table For information on the Parameter Sweep Properties dialog see the Reference manual To open double click or create a Parameter Sweep Parameter Sweep Properties Simulation to Sweep pc be Cancel E Para ESTA Help Recalculate Mow T Automatic Recalculation Factory Defaults Sweep Range nr Linear Number of Points 101 Start Value 1 Log Points Decade Linear Step Size E Searels List of Values ear List AAA ER ee HEHE RO ack HARE E EA E E ERA E A A E Y EL Simulation to Sweep Chooses which simulation to use for the parameter sweep The selected simulation will be recalculated for each different value of the variable chosen below 101 Simulation 102 Variable to Sweep Specifies which variable gets changed to create the sweep All variable
174. ded significantly reduce the resonant frequency To obtain a feel for the significance of signal metal you may add extraneous metal to the substrate in Example 10 Box Modes and observe the shift in the transmission peaks Transmission line discontinuities disturb current flow and energy is lost from the transmission structure While this lost energy is typically small the Q of the resonant cavity is high and coupling at these frequencies is significant Removing the cover of the enclosure causes energy to be lost to free space and resonance effects are reduced This greatly reduces coupling between metal segments of the circuit and it is evident in the responses given in the Box Mode example cited earlier with the cover removed Effects of removing a top cover are illustrated in the Examples EdgeCoupledOpen WSP and Box Modes WSP See your Examples manual for details A similar benefit may be derived by placing absorber material on the cover or in the cavity While the poor ultimate rejection in the stopbands of filters is not recovered heavy 285 Simulation coupling between segments is avoided This is sometimes necessary to eliminate oscillations of high gain amplifiers in oversize enclosures By far the most elegant and safest approach to minimizing box mode problems is placing circuits in small enclosures 286 EMPOWER Theory This section gives a technical description of the basic EMPOWER algorithms Unlike most simil
175. del if the freq variable is used the model is calculated once per frequency and FREQ is just a normal number 113 Simulation 114 e Post processed variables cannot be used in IF THEN statements For example IF DB S21 gt 5 THEN Gain Gain 10 is not legal Instead you should use the IFF and IFTRUE functions In this case you can state Gain Gaint IFTRUE DB S21 gt 5 10 This is because the equations are only calculated once not at each frequency e Al calculations are deferred until requested This means that when any of the statements shown above are encountered the required calculation is simply noted Later when the data is needed the calculation is performed What does this mean to most users Simply that post processed calculations are very fast do not require a lot of memory overhead and only calculate when necessary e The USING statement is a big convenience if you are writing many expressions With it you only need to specify the simulation data and design once The USING statement applies for all measurements specified after it and it does not carry over into functions For example USING Linear1 FILTER Gain DB S21 InputReflection DB S11 OutputReflection DB S22 Delay GD S21 Note You must specify the period before the measurement This tells GENESYS that you are getting post processed data If you leave out the period you will get errors like Unknown Variable S11 Several functions in GE
176. described below The assignment line assigns a value to a variable The assignment statement calculates the value of the expression and then gives the value to the specified variable Variables are not case sensitive for example VAR and var are the same Accuracy is IEEE double precision about twelve digits The format is Variablename Expression Examples X 2 R 4 3 2 4 9 8 Voltage 2 R Current Assignments can define a value to be a variable which allows that variable to be tuned optimized or included in the Monte Carlo analysis All variable names must start with an alpha character The rest of the name may contain letters numbers and the underscore _ character The tune statement format is VariableName Value Examples X 2 Large_R 3 54e 16 The tune statement must be a single assignment not an expression Therefore the following statement is illegal X 2 2 WRONG This statement creates a reference to an expression expression must be a simple variable array element or post processed data This can make your equations faster and easier to write The format of the reference statement ts REF Variable expression Example B 5 REF A B A now points to B 103 Simulation 104 C A A C now equals 10 A C B and indirectly A now equals 10 D VECTOR 20 REF A DI C A points to D 10 A 3 14 D 10 now equals 3 14 A line is considered a comment if the first character in the line is an
177. discrete Fourier transforms of the GGF eigenvalue vector using the Prime Factor algorithm This stage is based on the maximal utilization of internal symmetries of the bounded equidistant grid and usually takes negligibly small CPU time Moteover it can be done only once for all structures with the same box media and grid The described technique is quite similar to the main matrix filling procedure designed for the spectral domain technique Hill Tripathi 1991 except that it has been done here in finite space and we calculate the GGF matrix elements without additional truncation or series summation errors It can also be reformulated in matrix form in accordance with Pregla Pascher 1989 The GGF matrix can be represented by a sum of Toeplitz and Hankel matrices and their rows can be obtained directly from the general sums arrays The informational multiport term was introduced by B V Sestroretzkiy 1987 and in a nutshell means a model multiport that reflects electromagnetic properties of an object before superimposing an additional boundary condition It comprises information about EMPOWER Theory all possible structures that could be formed by different combinations of the additional conditions The boundaty condition superimposing can be represented as a set of simple manipulations with the informational multiport terminals We have added this section to clarify connections of the numerical electromagnetic solution with the circuit theor
178. e If several linear elements are used in the system schematic and simulation speed is an issue then linear element circuits can be moved to new schematics and then linked into the system schematic using a Network block This Netwotk block will then point to this newly created schematics Intermods One of the largest time consuming operations in SPECTRASYS is the calculation of a large number of intermods due to a large number of input signals into a non linear device such as a mixer or amplifier You can disable the calculation of intermods and harmonics until the initial architecture and basic budget parameters are set This can be done by unchecking the Calculate Intermods and Harmonics checkbox on the Calculate tab of the System Simulation dialog box If a large number of intermods are to be calculated due to a large number of input sionals the best thing to do is to first establish the architecture and make sure that system is performing as expected for a small number of input signals It is much faster to optimize the architecture with a small number of input signals rather than wasting time waiting for complete system analysis for issues that can be resolved with far fewer input sionals There are also different intermod and harmonic calculation modes that can increase the simulation speed See the Calculate Intermods and Harmonics section for additional information of these modes Analyzer Mode During the system s
179. e This option has a checkmark beside it when selected Toggle Animation When selected the viewer animates the image in real or angle mode This is accomplished by multiplying the individual currents by exp jw where w cycles from 0 to 2p1 and showing a sequence of snapshot images for increasing w This option has a checkmark beside it when selected Toggle Scale When selected the viewer displays the scale in the lower left of the viewer window This option has a checkmark beside it when selected Toggle Value Mode Real Mag Ang This option selects the current display option The options include the Real current value for current distribution snapshots and animation Magnitude for time averaged current values and Angle for the current phase delay distribution snapshots Togele Wireframe When selected the viewer displays a wireframe version of the current plots A wireframe is created by drawing the outlines of the EMPOWER grid currents without filling the resulting polygons When this option is not selected the viewer fills the polygons resulting in a solid surface plot of the current patterns This option has a checkmark beside it when selected Load From User View 1 10 Loads the previously saved viewer settings for the selected view Saved settings can also be restored by pressing the number key corresponding to the desired setting Save To User View 1 10 Saves the current viewer settings in
180. e Now button This launches EMPOWER to simulate the layout Note While EMPOWER is calculating a window similar to the one in below will be shown This window shows the current status throughout the calculation mode For more details on this window see the Basics Console section 207 Simulation BREMI EMPOWER Log Running Workspace layonly Press Escape to stop the EMPOWER run EMPOWER Planar 3D EM Simulator Version 7 06 lt C gt 1998 99 Eagleware Corp FREQC 11666 MHz gt Mode lt DISC gt ViewtX gt Loss lt xX gt Thin lt xX gt S ymm lt YZ MIRR gt Estim time 66 66 61 Each frq 66 66 61 Estim RAM 346K xe Starting Line Analysis to De embed PORT 1 9566 MHz Zo 44 932 G i286 936 11666 MHz Zo 45 046 G i326 651 Starting Discontinuity Analysis 8066 MHz S11 1 46 lt 295 21 5 92 lt 204 9566 MHz 11 263 lt 1 6 S21 16 2 lt 95 8 Viewing Results After EMPOWER simulation of the layout the data must be displayed in GENESYS This is done by creating a Data Output such as a Rectangular Graph To create a rectangular graph in this workspace 1 Right click on Outputs in the Workspace Window and Select Add Rectangular Graph from the menu Accept the default name Graph1 2 Select EM1 Stub for Default Simulation Data or Equations 3 Enter S21 for the first measurement and S11 for the second measurement This instructs GENESYS to display a window containing EMPOWER data S21 and S11 will
181. e calculations as any computer program must round off errors are inevitable This could cause a problem if you are using equality checks If this is the case change IF value 5 THEN GOTO LABEL to IF ABS value 5 lt 0 00001 THEN GOTO LABEL or something similar If you are using relational operators such as greater than gt or less than lt this point does not need to be considered This statement is used to define functions Functions take zero or more parameters as input and return exactly one value as output All variables used within a function are local that is variables cannot be shared across functions or with the main block See User Functions for detailed information on this statement The format of a FUNCTION statement is FUNCTION name parml parm2 equations RETURN expression An example function to calculate the inductance that resonates with a capacitor at a given frequency FUNCTION RESL C F L is in nH C is in pF F is in MHz FHz 1e6 F CFarads 1e 12 C Omega 2 PI FHz LHenties 1 Omega Omega CFarads Return LHenries 1e9 This statement returns a value from a function and exits the function Note that this statement does not mark the end the function declaration and a function with IF THEN 105 Simulation BASE statements can have more than one RETURN statement The format of the return statement is RETURN expression This statement defines the beginning index of arrays The defaul
182. e grid The grid cells with possible non zero conductivity currents metalization regions are depicted by the thick lines The thinning out procedure decreased the number of the currents in the problem and leaves the currents that are shown by the thick lines in the right half above This looks like a pseudo non equidistant grid over the regular grid that is finer near edges corners and via holes and coarser inside the solid metal regions The enlarged secondary grid cells after the thinning out consist of non divergent current borders along each side that can be substituted by two variables on the grid using linear re expansion Combination of these two procedures makes it possible to overcome restrictions of the MoL with a regular grid while keeping the main advantages of the equidistant grid The described procedure with total elimination of some currents inside the solid metal regions is called the wire model It basically substitutes a problem with another one with removed small metalization pieces It certainly gives an additional error but fortunately this error is opposite to the regular grid model error In other words the wire thinning out model actually increases the solution accuracy if the structure is thinned out properly However if too much metal is removed the thinning out error dominates Thus a solid thinning out model procedure was introduced to avoid it The solid model can be represented as a simple modification of the wire mode
183. e lines and multtmode EMPOWER data Further any multi mode elements connected together must have the same number of modes for each port Caution Do not connect standard lumped elements to a multimode port The results will not be correct If you will be connecting directly to components you should use single mode ports Use multi mode ports only for connection only with other multi mode ports and multi mode lines e They can be used with decomposition to accurately analyze much larger structures than would be possible in a single EMPOWER circuit See the Decomposition section for more details To create a multi mode port click on the Mode Setup Button from the EMPOWER setup dialog box when you start an EMPOWER run You will see a box similar to the one 245 Simulation 246 at the end of this section To make ports multi mode check the boxes between them EMPorts 1 2 and 3 form one multi mode port and EMPorts 5 and 6 form another multi mode port EMPort 4 is a single mode port To make a multi mode port you must follow these tules e All EMPorts for a multi mode port must be on the same wall e All EMPorts must have the same length line direction current direction and reference plane shift The EMPorts may and often do have different widths as above e All EMPorts must be Normal not No Deembed or Internal e Port numbers must be sequential and in order For example if you swapped ports 1 an
184. e magnitude of the vector sum of the currents entering all node at all frequencies is less than the specified absolute tolerance Maximum Amplitude Step The highest amount that the simulator will increase the amplitude of the independent sources during the search for a solution Normally set to 100 it can be set smaller to improve the speed of convergence for some circuits Minimum Amplitude Step The smallest amount the simulator will step increase the amplitude of the independent sources before the simulator tries another approach or terminates Frequency Resolution The minimum difference in frequencies before the simulator will merge frequency terms If the difference between two calculated frequencies usually mixed frequency terms is less than the frequency resolution they will be considered a single frequency term for simulation Maximum Number of Jacobian Reuse The largest number of times that a Jacobian matrix will be used before another Jacobian is calculated Notice that since HARBEC uses numeric techniques to calculate the Jacobian it can be reused many more times than with other harmonic balance implementations Full Jacobian Controls whether a full Jacobian or Fast Newton search step is taken during convergence Select automatic never or always Use Previous Solution As Starting Point Usually checked this option will start the convergence process using the previous set of node voltages If the parameters changed
185. e of the line s and determine propagation impedance and coupling values 2 D simulators are the fastest but most limited type of simulator available 3 D SIMULATORS 3 D simulators can analyze virtually any type of problem and are ideal for use with non planar geometries such as a coaxial T junction radar target reflections or other truly three dimensional problems 3 D simulators have the advantage that they can analyze almost any problem but they have the disadvantage that they are extremely slow 2 1 2 D SIMULATORS 2 1 2 D Simulators are simulators designed for mainly planar microstrip stripline etc circuits While they have less flexibility than true 3 D simulators they are much faster and are ideally suited for microstrip stripline and other similar geometries EMPOWER is an advanced 2 1 2 D simulator It can solve planar problems as well as problems with via holes and other z directed currents putting it in a class above true 2 1 2 D simulators which do not allow z directed currents In fact most people would consider EMPOWER to be a 3 D simulator because it can handle z directed currents All circuits in EMPOWER exist in a rectangular box as shown below The Media substrate layers each have specific dielectric and permittivity constants and loss tangents There must be at least two media layers One above the metalization layer and one below For standard microstrip there is a substrate below and air above For suspended
186. e of the screen The center of the viewer image window is always the center of rotation This option can also be selected by pressing Page Down L Rotate Right Button Rotates the current image counter clockwise in a horizontal plane perpendicular to the screen The center of the viewer image window is always the center of rotation M Rotate Left Button Rotates the current image clockwise in a horizontal plane perpendicular to the screen The center of the viewer image window is always the center of rotation N Rotate Down Button Rotates the current image backward in a vertical plane perpendicular to the screen The center of the viewer image window is always the center of rotation O Rotate Up Button Rotates the current image forward in a vertical plane perpendicular to the screen The center of the viewer image window is always the center of rotation P Top Button Shows a top down view of the current image This option can also be selected by pressing the Home key Q Front Button Shows a front view of the current image This view is from the y axis at z 0 This option can also be selected by pressing Ctrl Home R Side Button Shows a side view of the current image This view is from the x axis at z 0 This option can also be selected by pressing Ctrl End S Oblique Button 269 Simulation 270 Shows an oblique view of the current image This view is top down on the x y plane with
187. e system simulation the analyzer will create an analyzer trace for direction of travel for every node in the system Consequently for systems with large number of nodes the convolution routines used to calculate the analyzer traces alone can be time consuming if the analyzer properties are not optimized If simulation speed is important then using the narrowest filter shape will have the best simulation speed File Size The size of the data file will increase when the analyzer mode is enabled Furthermore the file size can grow rapidly depending on the settings of the analyzer mode For example the smaller the resolution bandwidth the more data points are needed to represent the data the larger the data file will be and most likely the simulation time will increase SPECTRASYS System Analyzer Troubleshooting What does it mean when the signal doesn t seem to be lined up with the integrated spectrum All this means is the frequency resolution isn t small enough to accurately represent the signal of interest If this is the case there are a few things that can be done to increase this resolution First the resolution bandwidth can be reduced If this is inadequate the Limit Frequencies feature should be enabled and the user can specify the Start Stop and Step frequencies used for the analyzer System Simulation Parameters Options Tab This page contains miscellaneous SPECTRASYS options Tip Any of the parameters in
188. e to deal with the frequency translation through elements such as mixers frequency multipliers etc In order to make this measurement three signals tones must actually be present at the input port 1 main channel signal 2 first interfering signal tone and 3 second interfering signal tone Furthermore the spacing of the two interfering tones needs to be such that intermods will actually fall into the main or primary channel If these conditions are not met then no intermod power will be measured in the main channel Values Real value in MHz Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators None Examples Measurement Result in graph Smith chart Result on table optimization or yield TCF TCF TCF Not available on Smith Chart This measurement is the integrated noise power in the main channel along the specified path For example if the Channel Measurement Bandwidth was specified to 1 MHz and the Channel Frequency was 2000 MHz then the CNP is the integrated noise power from 1999 95 to 2000 05 MHz This measurement includes ONLY NOISE traveling in FORWARD path direction through the node that fall within the main channel Values Real value in Watts Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DBM CNP channel noise power in dBm Real
189. e v2 line 2 time v1 8 Click OK and the graph displays the input and output waveforms as shown below tt AT ht TIME 2 TIME 1 Hesse Time ns ell i 4m TIME 1 Walkthrough DC Linear HARBEC 9 Inthe Workspace window right click on the Simulations Data node and select Add Parameter Sweep Name it Input Power Sweep 10 Enter the following values as shown below Simulation to Sweep HB1 Variable to Sweep IN Type of Sweep Linear Number of Points Start Value 40 Stop Value 0 Number of points 10 Click OK Parameter Sweep Properties Simulation to Sweep HB 1 o Cancel Variable to Sweep JIN z Help Recalculate Mow Automatic Recalculation Factory Defaults iDEA M Sweep Range Type OF Sweep f Linear Number of Points 10 Start value 40 C Log Points Decade C Linear Step Size E List of values ae y Stop Yalue 0 11 In the Workspace Window right click on Outputs node and select Add Rectangular Graph Name the Graph Output vs Input Power 12 Enter the following Default Simulation Data or Equations Input Power Sweep Amplifier Measurement P2 900 13 Click OK Click the Calculate icon in the toolbar and the graph displays Output Compression as shown below 15 Simulation J GENESYS 7 5 Output vs Input Power Workspace HB2 Mi I D 5 D S N a D o 16 Walkthrough SPECTRASYS The f
190. e values would not allow the user the ability to tune these parameters Furthermore the Step and Repeat function can also be used with source files that contain relative values The number of points parameter is not needed for this particular type of source since each frequency point is specified in the data file The following data is a source file example UNITS HZ DBC Nominal frequency FREQ 0 If freq is zero data is SSB offset DATA 1 30 10 50 100 70 1000 80 10000 90 100000 95 le6 100 ENDDATA 95 Simulation 96 The source file consists of keywords comments and the actual frequency amplitude and optional phase data NOISE Broadband noise can be added to any CW Modulated or User Defined source Noise is added to these sources by checking the Broadband Noise checkbox Noise is specified by upper and lower frequency limits and spectral density The noise spectral density is the power in dBm in a 1 Hz bandwidth For a noise only source the user can un check the Include Signal checkbox Source Parameter Tuning Every source parameter can be tuned by placing a question mark in front of the parameter Summaty All sources in SPECTRASYS have bandwidth and spectral density Sources have a center frequency bandwidth power level phase shift and number of points All sources are defined in the frequency domain e Sources ate Modeled in the Frequency Domain e Currently Time Varyin
191. econd order intercept Reverse Isolation Attenuation from the output to the input The reverse isolation is assumed to be flat across frequency Reference Impedance Input and output impedance of the amplifier Corner Frequency The frequency at which the input signals will begin to be attenuated by the Rolloff Slope dB Decade parameter Rolloff Slope dB Decade The slope of the frequency rolloff specified in dB attenuation per decade in frequency The following diagram is a high level view of the operation of the amplifier 67 Simulation Parameter Noise Figure Bandvridth Effe cts No Rolloff for Noise RF Amplifier Model using ideal elements The amplifier operation is as follows ll Determine Total Input Power The entire input spectrum of the amplifier is integrated to determine the total input power Add Noise Noise is added to the input spectrum The noise may be modified as the amplifier enters compression Determine Amplifier Gain The actual gain of the amplifier will depend on how close the amplifier is to compression and saturation A polynomial curve fit is done between the small signal linear gain curve and the output P1dB and saturation points to determine the actual gain curve of the amplifier Using the input power and the non linear polynomial gain curve the actual gain of the amplifier can be determined Create Intermods and Harmonics Using the non linear parameters of ou
192. ed number of harmonics and intermods will be used Calculation Automatic Recalculation Checking this box will cause the harmonic balance simulation to be run any time there is a change in the design If the box is not checked the simulation must be run manually either by right clicking on the simulation icon and selecting Recalculate Now or by clicking the recalculation calculator button on the main tool bar Auto save Workspace After Calculation Checking this box will cause GENESYS to save the current workspace after the simulation is complete This is particularly useful with long simulations or simulations that run overnight If this box is checked when optimizing the file will be saved after each optimization step Recalculate Now Dismisses the dialog box and starts the simulator if required If the circuit has already been simulated and has not been changed the simulator will not calculate again Oscillator Frequency Search Only Just perform analysis of oscillation frequency not full HarBEC simulation Noise Parameters Calculate Nonlinear noise Adds noise tone This options allows the user to add a noise tone with its harmonics to the simulation Noise Tone Frequency in Hz of a noise tone that will be added to the harmonic balance simulation Maximum Noise Harmonics Maximum number of noise tones that will be used in the harmonic balance simulation 45 Simulation OK Dismisses the dialog box If au
193. ed to solve the problem The axes in the metal plane grid plane correspond to the X and Y axes in the box The origin of the coordinates X and Y correspond to the geometrical origin of the box 0 0 in LAYOUT The z axis perpendicular to the metal plane corresponds to the plotted current voltage values The red color on the axis is for high values and dark blue is for zero The color coded scale makes it possible to evaluate actual values of current density The plotted values are an additive function of interpolated X and Y components of the current density The current components are calculated along the cell sides not at the corners of the cells The X and Y current components are interpolated to the grid corners and are then added The X Y current display provides general insight into circuit behavior Again consider the view given above The dominant eigenwave of the stripline is excited at the left input of the structure Observe the typical current distribution in the cross section X 0 click the side view button for a better look at this At this time the current declines to almost zero at the right output click the Front view button This confirms a line length of 90 degrees Next animate the response by clicking on the Animate button again Notice how the dominant stripline wave propagates in the structure The animation is a simple set of snapshots for the subsequent time moments The time will vary between zero and the period of the inc
194. eep e Ability to simulate problems too large to otherwise run The main disadvantages of decomposition ate e Tedious to setup circuit The simulation requires multiple EMPOWER runs combined with a schematic e Box modes and other phenomena related to the entire problem are not modelled However since EMPOWER uses mode space to model coupled line connections this is less of a problem that it would be with other simulators e Losses in the connecting lines are not modelled Decomposition can be applied to circuits with parts which are connected via single or multiple transmission lines Some typical circuits which can be broken apart are shown below In each of the circuits the unshaded areas are simulated individually The pieces are then combined using multi mode transmission lines to connect the pieces representing the lines in the shaded area 249 Simulation Edge Coupled Filter Spiral Inductor Interdigital Meander Line Filter For decomposition to be possible you must be able to break the circuit down into rectangular areas which are interconnected with transmission lines For example the spiral inductor above is broken down into four rectangular areas one for each corner These sections are then connected with multi mode transmission lines In each of the circuits above the three main advantages of decomposition can be seen e The lengths of the connecting transmission lines can be varied In the spiral i
195. eferred to the IM3 Analysis or IM3 Pass This 2nd analysis should will increase simulation time and thus should not be enabled unless intermod measurements are requested For the Manual mode the configured sources in the main analysis are used for the intermod measurements Manual Advanced Mode For this particular mode the user must create a minimum of 3 sources The first source represents the desired signal in the main channel in which the intermods will actually be measuted The Channel Measurement Bandwidth must be set to the appropriate bandwidth to include all of the intermod power Furthermore the in channel gain is need to correctly determine the input third order intercept point The two or more other sources are the actual signals that are used to create intermods in the main channel The user must make sure that the desired signal and the interfering tones are spaced properly such that intermods will fall within the bandwidth of the main channel Furthermore for this particular technique there is no restriction on the number of interfering signals used to create the intermods The intermod power found within the channel will be used for the intermod measurements For this mode of operation the user needs to only specify the frequency offset from the desired channel to the first interfering tone If at least 3 sources are not created at the correct frequencies and the tone offset is not set correctly intermods will not appear
196. eg MHz e DA s21 DA s11 The display below is after the EMPOWER run with 31 points The response has not changed noticeably since the 11 point simulation so we must have found the correct notch frequency BE Grapht Workspace layonly 0 175 dB aie ie le leh ee en co Sere ae dl o D a S CJ EN D Freg MHZ DA 21 DB E11 For the example filter the notch occurs at 9 2 GHz instead of the desired 9 5 GHz Much of this shift is due to rounding the line dimensions to the nearest 5 mils Using the Viewer 210 Once the EMPOWER tun is completed the viewer can be loaded if Generate Viewer Data was selected in the EMPOWER options dialog Generating this data slows the EMPOWER simulation so it s usually only checked during last run simulations EMPOWER Operation File View x2 a Mao Sold Freq GHz 3 2 el s 4 ar Top Front Side Oblique Right Click the EMPOWER simulation in the Workspace Window and select Run Viewer A top down view has been selected and the notch frequency has been specified Port 1 is at the left of the image and port 2 is at the right The plot is color coded to the scale given in the lower left of the figure Notice that port 2 is nearly black This indicates that very little energy is being delivered to that port at 9 2 GHz as we d expect Creating a Layout From an Existing Schematic The file used in this e
197. eixner 1972 That is why a global approximation order of the problem is usually lower and the largest calculation error part for integral parameters of a structure Y S matrix elements characteristic impedance decreases usually proportionally to the grid cell size That is the monotonic convergence was observed for almost all problems solved on the initial equidistant grid This makes it EMPOWER Theory possible to use such powerful convergence acceleration techniques as Richardson s extrapolation Richardson 1927 Marchuk Shaidurov 1979 Note that this is an observation and it cannot be proven to work for all problems The technique used here for the descriptor matrix evaluation using current sources in the metal plane is empirical The evaluation accuracy depends on parasitic high order modes that could be excited by current sources and if they are close to their cutoffs or even are propagating the estimated descriptor matrix could be far away from the correct one This can be expected however since real circuits which have unexpected high order modes near the cutoff usually do not work properly either empower S B Worm R Pzegla 1984 K S Yee 1966 Also T Weiland 1977 B Sestroretzkiy 1977 Cx BA G Kron 1944 24 The Grid Green s Function GGF has been mentioned quite a few times The GGF is a solution of the differential difference analogue of Maxwells equations A 1 excited by a unit grid current J
198. elp Generate Viewer Data Slower Checking this box causes EMPOWER to generate a EMV file that can be loaded in the EMPOWER current voltage viewer program Selecting this box will increase the amount of time required to solve the problem This 227 Simulation 228 box must also be checked in order to generate far field radiation data See the Viewer section for more information Port number to excite This option is available if Generate viewer data above is checked It specifies which EMport to excite for viewer data By default mode one is excited but if the input is multi mode then you can add the option Imj to excite mode j instead Mode number to excite This option is available if Generate viewer data above is checked It specifies which mode to excite for viewer data Generally mode one is excited but if the input is multi mode then you can add excite any mode number up to the number of modes at that input Generate Far Field Radiation Data Checking this box causes EMPOWER to generate data for the radiated electric fields of a structure in the far field region The data generated is specified by the sweeping theta and phi coordinates of the spherical coordinate system Sweep Theta This option is available if Generate Far Field Data above is checked It generates data for varying theta in the spherical coordinate system Theta is the angle formed from the z axis to a point in 3 space If Sweep Th
199. ement Channel Bandwidth to 5 MHz Ifa carrier is injected into the input of the amplifier at 1990 MHz then all measurements along the path will integrate their spectrums from 1987 5 to 1992 5 MHz 1 e 1990 2 5 MHz See System Simulation Dialog box General Tab Channel Path Frequency Since each spectrum can contain a large number of spectral components and frequencies SPECTRASYS must be able to determine the area of the spectrum over which to integrate to determine power levels A Channel Frequency and a Measurement Bandwidth define this integration area SPECTRASYS can automatically identify the desired Channel Frequency in an unambiguous case where only one frequency is on the from node An error will appear if more than one frequency is available In this case the user must specify the intended frequency for the designated path A unique Channel Frequency exists for each node along the specified path Consequently each node along the path will have the same Channel Frequency until a frequency translation element such as a mixer is encountered SPECTRASYS automatically deals with frequency translation through a mixer The individual mixer parameters of Desired Output Sum or Difference and LO Injection High of Low are used to determine the desired frequency at the output of the mixer A mixer is the only device that causes a frequency translation of the center frequency For the following
200. ement is the peak current through the specified current probe The probe is identified by a probe designator name Values Real value in specified units Simulations Nonlinear dc analysis Default Format Table MAG Graph MAG Smith Chart none Commonly Used Operatots Operator Description Result Type MAG I1 linear magnitude of voltage at probe 1 Real Other Operators DB ANGI ANG360 RE IM Examples Measurement Result in graph Smith chart Result on table optimization or yield ICP1 MAG ICP1 current through current MAG ICP1 probe 1 Not available on Smith Chart 163 Simulation 164 This voltage measurement is the peak voltage at the specified node The node is the node number or the name of the node as specified by the voltage test point designator name Values Real value in specified units Simulations Nonlinear dc analysis Default Format Table MAG Graph MAG Smith Chart none Commonly Used Operators Operator Description Result Type MAG V1 linear magnitude of voltage at node 1 Real Other Operators DB DBM ANGI ANG360 RE IM Examples Measurement Result in graph Smith chart Result on table optimization or yield VTP2 MAG VTP2 voltage at test point TP2 MAG VTP2 Not available on Smith Chart The reference impedance measurements are complex functions of frequency The measurements ate associated with the network terminations The frequency range and interval
201. en stated as sufficient to insure stability Theoretically K gt 1 is insufficient to insure stability and an additional condition should be satisfied One such parameter is B1 which should be greater than zero Bl 1 S11 S22 De 0 Stability circles may be used for a more detailed analysis The load impedances of a network which ensure that S11 lt 1 are identified by a circle of radius R centered at C ona Smith chart The output plane stability circle is Linear Simulation Cout S22 DS11 S22 D 3 Rout S12S21 S22 D This circle is the locus of loads for which S411 1 The region inside or outside the circle may be the stable region The input plane stability circle equations are the same as the output plane equations with 1 and 2 in the subscripts interchanged Shown in the figure below are the input plane stability circles on the left and the output plane stability circles on the right for the Avantek AT10135 GaAsFET The shaded regions ate potentially unstable At the input the stability circle with marker 1 indicates sources with a small resistive component and inductive reactance of about 200 ohms are unstable Circles 2 and 3 are also unstable with low resistance and certain inductive source impedances At the output plane on the right at 500 MHz a wide range of inductive loads is potentially unstable MAG SE1 MAG SE1 MAG SE2 gii 1500 q oon gii EN 4000 En 1 03834 1 3315 3
202. enna Theory and Technology ATT 94 Moscow Russia 23 25 August 1994 p 352 356 309 Simulation 310 K N Klimov V Yu Kustov B V Sestroretzkiy Yu O Shlepnev Efficiency of the impedance network algorithms in analysis and synthesis of sophisticated microwave devices Proc of the 27th Conference on Antenna Theory and Technology ATT 94 Moscow Russia 23 25 August 1994 p 26 30 V Yu Kustov B V Sestroretzkiy Yu O Shlepnev TAMIC package for 3D electromagnetic analysis amp design of MICs Proc of the 5th Intern Symp on Recent Advances in Microwave Technology ISRAMT 95 Kiev Ukraine September 11 16 1995 p 228 233 Yu O Shlepnev B V Sestroretzkiy V Yu Kustov A new method of electromagnetic modeling of arbitrary transmission lines Proc of the 3rd Int Conference Antennas Radiocommunication Systems and Means ICARSM 97 Voronezh 1997 p 178 186 Yu O Shlepnev B V Sestroretzkiy V Yu Kustov A new approach to modeling arbitrary transmission lines Journal of Communications Technology and Electronics v 42 1997 N 1 p 13 16 originally published in Radiotekhnika 1 Elektronika v 42 1997 N 1 p 13 16 Yu O Shlepnev A new generalized de embedding method for numerical electromagnetic analysis Proceedings of the 14th Annual Review of Progress in Applied Computational Electromagnetics Monterey CA March 16 20 1998 v II p 664 671 Yu O Shlepnev E
203. eq MHz Specifies the maximum frequency to analyze Number of Points Specifies the number of frequency points to analyze Points are distributed linearly between the low and high freq specified above HARBEC Fregs Select this box to cause EMPOWER to simulate the layout at each frequency calculated by the harmonic balance simulator Checking this box makes sure that EM results are available at all frequencies so that the data will not need to be interpolated or extrapolated for harmonic balance analysis Max Critical Freq MHz Specifies the highest important frequency that will be analyzed on any run of this circuit MAXFRQ 1s specified in the units defined in the DIM block The default units are MHz Parameters of the solution quality thinning out thresholds and lengths of lines for de embedding are based on the maximum critical frequency value In other words this value influences both accuracy of simulation and calculation time Decreasing the value accelerates simulation but may increase model error especially at frequencies above the value On the other hand an unnecessarily high value may slow down the solution without visible improvements in accuracy EMPOWER Basics Note An important reason to specify MAXFRQ By default this value is set equal to the highest sweep frequency specified in EMFRQ Even a small change of its value may cause the grid to change forcing recalculation of de embedding parameters and unnecessarily
204. er from the right click menu of an EMPOWER simulation Workspace Window in GENESYS This section describes the viewer menu items and buttons It can be used to become acquainted with the interface in general as well as as a reference section A sample viewer screen is shown below The objects in this figure are described below A B G HI1JKLMNOP O RS em 0wer Viewer Y6 5 le view C xz a Mag Solid Freg GHz 8 8 e 9 2 Top Front Side Oblique A File Menu Open Opens a new viewer data file Exit Exits the viewer 265 Simulation 266 Toggle Background Color Toggles the background from black to white or white to black A white background is normally selected before a screen or window print Print Screen Sends a copy of the entire screen to a bitmap file or to a printer Print Window Sends a copy of the viewer window to a bitmap file or to a printer B View Menu The objects in this menu affect how the current image is displayed Top Home Shows a top down view of the current image This option can also be selected by pressing Home Front Ctrl Home Shows a front view of the current image This view is from the y axis at z 0 This option can also be selected by pressing Ctrl Home Side Ctrl End Shows a side view of the current image This view is from the x axis at z 0 This option can also be selected by pressing Ctrl End Oblique End Shows an obl
205. er intermod gain in dB Real Measurements SPECTRASYS MAG CGAINIM3 numeric value of the cascaded third order intermod gain Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DB CGAINIM3 DB CGAINIM3 DB CGAINIM3 MAG CGAINIM3 MAG CGAINIMS3 MAG CGAINIMS3 Not available on Smith Chart This measurement is the ratio of the Desired Channel Power to Channel Noise Power along the specified path as shown by CNR n DCP n CNP n dB where n stage number Both the Desired Channel Power and Channel Noise Power measurements use the main channel Note See the Desired Channel Power and Channel Noise Power measurements to determine which types of signals are included or ignored in this measurement Values Real value numeric Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DB CNR carrier to noise ratio in dB Real MAG CNR numeric value of the carrier to noise ratio Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DB CNR DB CNR DB CNR MAG CNR MAG CNR MAG CNR Not available on Smith Chart This measurement is the cascaded noise figure in the main channel along the specified path The Cascaded Noise Figure ts equal to the Channel Noise Power measurement at the output of stage n minus the Channel Noise Po
206. er measurement to select a subset of a sweep Its format is operator measurement Qvalue where value is the independent value or range to pull data from For ranges separate values by colon For multidimensional data multiple ranges can be specified separated by commas The values can be the actual independent frequency etc data or can be Hindex where index is the zero based index of the data to use such as a harmonic number in a nonlinear simulation Some examples S21 900 Gives all data from S21 at 900 MHz If the data comes from a parameter sweep then the result will be a sweep of values all at 900 MHz vs the swept parameter P2 3 Returns the power in dBm at port 2 at the fourth data point counting DC that is the third harmonic for a single tone simulation 143 Simulation 144 MAG V5 0 3 1 3 Returns the magnitude of the voltage at node 5 from 0 to 3 for the first swept parameter and from 1 to 3 for the second parameter All measurements have default operators For instance on a table using 21 will display in dB angle form and Z32 will display in rectangular real amp complex form Likewise on a graph S21 graphs in dB while Z32 graphs the real part of Z32 Note To avoid confusion measurements used in equations for post processing must specify an operator Operator Description Meas must be Result Is MAGANG Linear magnitude and angle in range Complex Complex 180 to 180 MAGANG360
207. er to always use the Jacobian or never use the Jacobian On the HARBEC Options dialog box you can specify either Automatic Always or Never use of the Full Jacobian Experimenting with different values may improve convergence speed Order vs Accuracy and Time The easiest way to affect simulation performance is to change the order of the frequencies used in simulation Harmonic balance models signals in the circuit by using a finite number of harmonics of the fundamental signals and a finite number of mixing terms The larger the number of harmonics and mixing terms the better the approximation of the actual signals However the larger the number of frequencies the longer the simulator takes to work The length of time to take a search step is roughly proportional to the cube of the number of frequencies So doubling the number of frequencies will take about 8 times longer to simulate 53 Simulation 54 However if not enough frequencies are present to adequately model the signals then the results will not be accurate Moreover the simulator may have difficultly converging if not enough of the energy in the circuit is modeled The best practice in selecting order is to start with a reasonable number of harmonics of each signal typically 5 is a good point then increase the number until the results stop changing Order and Maximum Mixing Order on the HARBEC Options dialog box control the number of terms In this way you ca
208. erFinalRecomp wsp E Notes BGENESYS ID simulation 5 Data EJEMPOWER Y E EMPOWER r1 E EMPOWER r2 E EMPOWER r3 E EMPOWER rd E EMPOWER SS E EMPOWER LST E EMPOWER AGF E EMPOW ER TPL EA Optimizations E Global Equations Note Previous versions of GENESYS used actual disk files for all internal EMPOWER files and separate subdirectories were recommended for each circuit This is no longer necessary for typical usage If you need to access these internal files in a workspace you have two options 299 Simulation 300 e Right click on the EMPOWER simulation on the tree and select Write Internal Data Files This automatically creates a directory with the same name as the simulation and places copies of the files there e Inthe same workspace you can access internal files using a special file prefix WSP followed by folder names and the filename For example to access the EMPOWER SS use the name WSP Simulations EM1 EMPOWER SS The second method has the advantage of automatically updating whenever the EMPOWER simulation is re run The first method requires you to re write the data files whenever you need an updated version There are two basic types of data files text sometimes called ASCII and binary Text files are human readable files They are universal and can be edited with many different programs such as NOTEPAD or DOS EDIT Among the text files used by EMPOWER are b
209. erance eecerssessessessenseseees 43 32 A eee ee eet a cet 8 A nauactata loubsehesss sckeabukouelan tones 41 Binan ladra 300 A ree E ee rene ere me 10 41 Bottom COVE oeccccccccccccccccccccccccocccccccecccceees 217 294 A 10 Do Soe 1 200 221 234 241 259 ACCAC E E 2212337299 Box MOS cecccccccccccccccccccccees 1 236 283 284 285 Adding Broadband Noelia isis 81 AA A A 119 Built in FUNCtiONS cccccccccccccccccccccccccccccecees 107 112 AIM cancaconraranoncanonnanoacinncninnacinnccinon carr ccirracaciinss 119 cetonas 116 A a R 36 141 PAV WAN Gla Sl da 217 236 C A DOW sna A 217 Aer S a OE 287 Calling C C PrograMS cocinas 117 Ammeter EPE AEE EE E EN E E E 5 8 Cavity Absorber mociones 285 Amplifier Ao 10 23 Cavity AOE EE 283 Amplifiers s ER 67 Ciste oe aot 221 233 237 273 287 dn PERU os Cemtering css 205 BIND A AN 106 CFP A IS 221 PINE anes AN N A EE NE S E 107 143 Channel Path Frequency cms 69 ANG OU ata 107 143 Characteristic impedance vscssssssusesseneeenseee 247 Angle A A 143 265 CATA CEST aan ados 1 Animate DUO ibi 265 273 CU ccoo esta 32 38 39 141 145 NOOO an 5 8 41 Coaxial T junction mice 217 ARCCOS vresssssesessseeesssseseesseeeesnsseseernsseeeensse 107 CONCE DEY see E E 71 ARECOS triada 107 COMBINE WSP 250 ARCSIN rail 107 Compensation AdMittANCE occ 302 ARCSIN ada 107 o S AN 107 ARG EA ostenta 107 Components conca 221 259 ARETAN a aiii 107 Composite Spector 88 A E E E aeeceedasaee 106 Compte nean 1
210. ermine which types of signals are included or ignored in this measurement The only difference between this measurement and the Desired Channel Power DCP measurement is that this measurement applies to the IM3 analysis pass only Consequently this will be the same measurement as DCP in the Calculate IIP3 TOD Manual Mode since a dedicated IM3 analysis is not created and the normal analysis is also the IM3 analysis pass Remember intermod bandwidth is function of the governing intermod equation For example if the intermod equation is 2F1 F2 then the intermod bandwidth would be 2BW1 BW2 Note Bandwidths never subtract and will always add The channel bandwidth must be set wide enough to include the entire bandwidth of the intermod to achieve the expected results The Automatic Intermod Mode will set the bandwidth appropriately Values Real value in Watts Simulations SPECTRASYS Measurements SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DBM DCPIM3 desired third order intermod channel power in dBm Real MAG DCPIM3 magnitude of the desired third order intermod channel power in Watts Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DBM DCPIM3 DBM DCPIM3 DBM DCPIM3 MAG DCPIM3 MAG DCPIM3 MAG DCPIM3 Not available on Smith Chart The Offset Channel Frequency and Offset C
211. ernal and ports 3 and 4 are internal EMPOWER will create a 4 port data file for this circuit YNET 1 gt Note Internal ports and no deembed ports must always have higher numbers than normal external deembedded ports In the figure above the internal ports are numbered 3 and 4 while the external ports are numbered 1 and 2 The data file created by EMPOWER can then be used in GENESYS The circuit on the right above uses the resulting data in a complete network First a FOU four port data device was placed on the blank schematic The name assigned to this FOU block was the name of the internal file from the EMPOWER run WSP Simulations EM1 EMPOWER SS An input and output were added on nodes one and two of the FOU block the ground was added to the ground node and a capacitor was connected across ports 3 and 4 This has the effect of putting the capacitor into the EMPOWER simulation This capacitor can then be tuned and optimized just like any other element in GENESYS When the S Parameters of MYNET are displayed you see the resulting S Parameters of the entire circuit One advantage of EMPOWER is its true integration In most electromagnetic simulators you would have no choice but to go through the complicated steps above Imagine how tedious this would be if you had 10 lumped elements 2 transistors and an op amp chip in the box Fortunately when EMPOWER is combined with SUPERSTAR SCHEMAX and LAYO
212. ers Composite Spectrum Tab This page controls calculation of Composite Spectrum Components and Spectrum analyzer mode Tip Any of the parameters in this dialog box can be made tunable by placing a in front of the parameter 61 Simulation system Simulation Parameters a o X General Paths Calculate Composite Spectrum Options 4 show spectrum L Contributors ia w deny Ici Componerts Above J dEm lv Enable Analyzer Mode Resolution Bandwidth ee Ji Filter Shape to 118dBc 60 ChanB w Factory Defaults 3 M Show Totals e Show signals E ie T Show Intermads 3 eee rs Show Noise fw Limit Frequencies Start i000 MHz Stop 2000 dE Step fi MHz Defaults to ia bandwidth i Randomize Noise I Add Analyzer Noise 150 dBm Hz Show Spectrum Contributors This is a graph and table viewing option that will allow the user to determine what is displayed This option only affects the displayed output and will not affect any internal calculations When checked the spectrum at a node can be broken down into general groups or individual components when displayed When unchecked only totals will be shown Spectrum identification will only occur when this options is enabled and the Identify Individual Components Above options is also enabled Identify Individual Components Above This threshold is used to show only individual spe
213. es and memoty requirements as small as possible while making accuracy as high as possible This section looks at several choices and clarifies the tradeoffs Table 3 1 lists various features and gives their impact on simulation times accuracy and memory requirements Each of these choices are looked at in detail below The values are approximate and may vaty Reducing Cell Size by 2 Raising Max Critical Freq Haag Syme Symmetry x1 4 to x1 16 EA o GO AA to x1 16 Off 2 Thinning Out Increasing Wall amp x1 1 x1 5 x1 1 Cover Spacing Choosing Correct Cover Ese ool Viewer a X Ee Data Corecting Slot x1 64 x1 256 Type Structure Using Preferred Box Cell Count Cells should be small enough so that the result is accurate at least 10 cells per wavelength at the maximum critical frequency see below Additionally the cells should be small enough that there is at least one and preferably more cell across every line and gap Decreasing the cell size makes all stages of the solution take longer so decreasing cell size can be an expensive way to get more accuracy Conversely increasing cell size is a great 233 Simulation 234 way to do an initial run of your problem to make sure that the result is close before you start a simulation that will take hours See the EMPOWER Basics section for more information on cells and the problem geometry This parameter is set in the EMPOWER dialog box when starting a simula
214. et the bandwidth appropriately Values Real value in Watts Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DBM TIM3P total third order intermod power in dBm Real MAG TIM3P total third order intermod power in Watts Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DBM TIM3P DBM TIM3P DBM TIM3P MAG TIM3P MAG TIM3P MAG TIM3P 195 Simulation 196 Not available on Smith Chart This measurement is the integrated power of the entire spectrum at the node This is an extremely useful measurement in determining the total power present at the input of a device 1 e amplifier or mixer LO This measurement includes ALL SIGNALS INTERMODS HARMONICS and NOISE traveling in ALL directions through the node that fall within the main channel Values Real value in Watts Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DBM TNP total node power in dBm Real MAG TNP magnitude of the channel power in Watts Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DBM TNP DBM TNP DBM TNP MAG TNP MAG TNP MAG TNP Not available on Smith Chart EMPOWER Operation An EMPOWER simulation requires a board layout description The easies
215. eta is unchecked a fixed angle will be specified and far field data will be produced only at this theta angle Sweep Phi This option is available if Generate Far Field Data above is checked It generates data for varying phi in the spherical coordinate system Phi is the angle formed from the positive x axis to a point projected on the xy plane in 3 space If Sweep Phi is unchecked a fixed angle will be specified and far field data will be produced only at this phi angle Thinning out subarid 5 Thin out electrical lossy surfaces T Solid thinning out slower accurate 7 Add extra details to listing file lv Use planar ports for one port elements e Show detailed progress messages T Only check errors and memory do not simulate Command line OF Cancel Apply Help EMPOWER Basics Only check errors topology and memory do not simulate Useful to make sure you have the simulation and layout setup properly before a long EMPOWER run This option provides a very important means both for checking the grid mapping and required memory EMPOWER just maps the problem onto the grid and calculates the required number of the grid variables for each frequency Check the map of terminals in the listing file to see the grid model of the problem and check the MEMORY lines in the listing file to get some idea about problem complexity and probable simulation time Setup Layout Port Modes Bri
216. ethod of simultaneous diagonalization MoSD Shlepnev 1990 1998 is used to extract a multimode or generalized S matrix The MoSD is based on the electromagnetic analysis of two line segments corresponding to an MIC structure port to be de embedded The segments have different lengths and the same surface current source regions as in the initial structure The result of the EM analysis is two Y matrices relating integral grid currents and voltages in the source regions These matrices transformed from the space of the grid functions to a space of the line eigenmodes are set equal to Y matrices describing independent modes propagated in continuous part of the line segments It gives the basic non linear system of equations relating eigenwave propagation constants and characteristic impedances a matrix of transformation from the grid functions space to the mode s space transformation matrix and an auxiliary matrix that helps to match propagated modes perfectly compensation matrix Solution of the system is based on simultaneous diagonalization of Y matrix blocks Each port of the MIC structure or discontinuity can be de embedded using the pre calculated line parameters and the transformation and compensation matrices The main advantages of this approach are the possibility of multimode deembedding without direct spectral analysis of the line cross section and ideal matching of line eigenmodes in the analysis of the line segment that increases the
217. etween each node in the circuit and ground to assist with convergence For example to change the value to 1 micro siemens enter gmin 1e 6 GminSteps Specifies the maximum number of Gmin steps used during DC analysis Default value is 10 These steps are used if there are convergence difficulties using the nominal value RelTol The relative accuracy to which the sum of node currents must sum to zero to achieve DC convergence The simulator is converged if the ratio of the vector sum of the currents into a given node currents to the sum of magnitudes of the current entering that node is less than the specified relative tolerance Default value is le 3 AbsTol The absolute accuracy to which the sum of node currents must sum to zero to achieve DC convergence The simulator is converged if the magnitude of the HARBEC DC amp Harmonic Balance vector sum of the currents entering a given node ata given frequency is less than the specified absolute tolerance Default value is 1e 12 It11 Specifies the maximum number of steps used in DC convergence Default value is 10000 SrcSteps Specifies the maximum number of amplitude steps used in DC analaysis When having difficulty finding DC convergence the HARBEC will automatically adjust the amplitude of independent sources in the circuit Default value is 10 The HARBEC harmonic balance simulator simulates the steady state performance of nonlinear circuits Circuits can be stimulated w
218. extracted as necessary and the resulting part value may be different at each frequency For example R 50 1 FREQ can be used to create a frequency dependent resistor Post Processed variables can be combined For example the statement Difference Linear1 Filter DB S21 Measured Data DB S21 gives the difference between the measured and the calculated DB S21 For any operator or built in function swept data will be linearly interpolated if needed and the resulting sweep will contain all frequency points from both the measured and the calculated data In the item above the difference variable will contain all data points from both the linear analysis and the measured data All operators and built in functions will work on post processed data For example the statement SineS SIN Linearl FILTER ANGJS21 will take the sine of the phase of S21 at each data point If the simulation data is itself a matrix everything will still work fine For example the statement Difference Linear1 Filter RECT S Measured Data RECTT S will take the difference of all s parameters The Difference variable will now behave like an array see the previous section with the addition that all operations will operate at all frequencies For example Difference 2 1 returns the difference of S21 at all frequencies FREQ 1s a post processed variable For each frequency point the value is that frequency All frequencies are in MHz Exception In a user mo
219. f a single source located on the start node If there is more than one source located on the start node the channel frequency is ambiguous and cannot be determined An error will appear in this case and the user must specify the desired channel frequency This frequency and the Channel Measurement Bandwidth make up the main channel for this path Delete Paths can be deleted by clicking the Delete button System Simulation Parameters Calculate Tab This page controls calculation of Intermods Harmonics Noise and IIP3 Tip Any of the parameters in this dialog box can be made tunable by placing a in front of the parameter SPECTRASYS System system Simulation Parameters de ihe Sie eee XE Haimonics and Intermods l 5 o Manual Pees Created From i Calculate Harmonics Tone Spacing EA curs Sources Only e Calculate Intermods Coal Signals fees Maximum Mixer Order 20 M Calculate Noize Ge ain 1 est Power Level 2 Tone Power Level fo wi Input Port a o dc Sustem ad Thermal Moise 4 173 51 de mHz Noise Points for Entire Bandwidth F a Add fi 00 ores hose ae IF nf 0000 MHz bandwidth at each signal frequency Default to channel bandit Factory Defaults iA 3 Toner ae Apply E Intermods and Harmonics For speed calculation reasons the calculation of harmonics and intermods can be disabled By default they are both enabled The user can also specify
220. files with other GENESYS users you must use a uniform location for these files Good locations include in the GENESYS Model directory or a standard directory every user has on their C drive Browse Clicking this button brings up a browse dialog box allowing you to search for your file Even if you already have the correct file this button is useful as the browse dialog will show you the contents of the file Model Subckt Name This combo box is automatically filled in with available models and subcircuits parsed from the spice file Select the model you want to use Spice Part This box is automatically filled in when the model subckt is selected In SPICE a model must be referred to using the correct type of part Occasionally you may need to override this selection Number of Nodes This is automatically detected from the type of model but can be overridden if necessary Reverse Nodes 1 amp 2 Unfortunately Berkeley chose the convention that for transistors node 1 is the output and node 2 is the input If this model is a transistor or is a subcircuit with an amplifier that uses this convention you should check this box This box ensures that the GENESYS pictures and node numbering conventions are modified accordingly when using this part The Designs Link to Spice File section in the User s guide has more detailed information 139 Measurements Overview GENESYS supports a rich set of output parameters All p
221. g Sources are not Supported e CW Sources are Defined to have 1 Hz Bandwidth e Modulated Sources can have any Bandwidth e A Modulated Source is Represented by a Uniform Spectral Density Synthesis Circuits can directly synthesized from SPECTRASYS Right clicking on the behavioral model will bring a context sensitive menu This menu will list the synthesis modules available for the given element The selected synthesis module will be invoked and the parameters of the behavioral model will be passed to this synthesis module See the specific synthesis section for more information about each synthesis tool SPECTRASYS System JE GENESYS V8 1 of x File Edit View Workspace Actions Tools Schematic Synthesis Window Help JOM s Be loc 98 paaa Be gt 417 0898 Lumed Line gt E A O E3 O RFAMP_1 cam o 2046 ATTNi Synthesize Subcircuit as Active Filter O WSO LaS Fanner as Microwave Filter Edit ern Find Part In Layout as Passive Filter E Synthesis i 3 3 Designs Models ARS a ee A Zoom In Ctl PgUp E Schl Schematic Zoom Out Ctrl PgDn 3 Simulations Data TY BPF_BUTTER A Zoom Maximum Ctrl Home o QE System Sch1 FLO SO MHZ Zoom Page ERRENA Sij BPF_BUTTER_1 04 4f FHIR250MHz l Zoom Rectangle x TE Outputs BA Output Spec OOOO OF tapass 3 00 II fi BPF_BUTTER_1R I ramax 100 dB Send To Back 3 2 Equations 3 Substrates 3 Optimi
222. gation constant relative to free space Comp Phase Compensation Admittance value of phase and impedance compensation for deembedding S MATRIX TABLES Each table gives the circuit s s parameters at one frequency For normal non multimode inputs as an example S21 is found in the row with input numbers 2 and 1 in that order Written by EMPOWER Type Text Can be safely edited Yes Average size 200 Kbytes to 2Mbytes but may vary Use Importing current data from EMPOWER into another application such as Matlab ot Excel This file contains two tables per frequency one each for x and y directed currents Each table contains 4 columns containing the x and y coordinates followed by the real and imaginary part for each current These tables could be edited but it would be best to leave them alone since they would be very tedious and error prone to edit them by hand These files should be very useful in other applications as the engineers at Eagleware used third party applications to graph currents before our EMPOWER viewer was completed Written by EMPOWER Type Text Can be safely edited Yes Average size 1 Kbyte Use Read by GENESYS when Generalized S Parameters are requested 303 Simulation 304 These files contain each port s impedance versus frequency These ports are read by GENESYS if the keyword GEN is used in place of a termination impedance The files are formatted just like RX files in GENESYS GENESYS a
223. gnator of the source GENESYS searches the specified design for all sources and places them in the table Freq The frequency specified on the source GENESYS fills in this value by reading the frequency from the schematic HARBEC DC amp Harmonic Balance Order The number of harmonics to be analyzed The larger the number of harmonics the more accurately waveforms will be represented However the length of time to find a solution increases as roughly the cube of the number of frequencies Order must always be set large enough to model the majority of the energy in each branch current Typical numbers for mildly nonlinear circuits are 4 5 For circuits deep in compression square waves present the order may need to be 8 16 to achieve the desired accuracy Maximum Mixing Order Specifies the maximum combined order of signals to be simulated In the example shown all 4th order products will be calculates For example the 1900 2 1905 1 1800 1 95MHz the mixer third order intermodulation term is a 4th order term 2 1 1 and will be calculated This term only affects the mixing terms and will not override the order of individual sources specified in the frequency table Temperature The temperature in degrees Celsius at which to perform nonlinear analysis Maximum Analysis Frequency Frequency above which no nonlinear analysis is performed If not checked all frequency points in the analysis input frequencies their specifi
224. gnetic theory To connect a lumped element for example we performed both serial connections of terminals along the element that corresponds to the electric field integration along the element and parallel connections that corresponds to the surface current integration across the element see the Table above The analogies described are meant to facilitate understanding of numerical electromagnetics Note that the examples given are not the only possible manipulations with the terminals with physical electromagnetic equivalents 295 Simulation Before filling the reduced GGF matrix we can additionally decrease the GGF matrix order and required storage space by means of thinning out with linear re expansion procedures and by incorporating a geometrical symmetry into the problem BERR RRR RRR RRR RRR RRR Ree eee eee eee gt ee TETEEETEEETEEETETEERTEEEEE E E E NAAA AN coe PEA E e o Ee e a a ma EB HEE SPS NE NE IENEI N A UNENE IRENE HEEE EE j am a pn BBE q SER CA ee ee HE es E TY A AAA AAA BA AAA A MOON 555550 MA BREE 66 BE 1 000 0000 Bs Be i ARAE eee a Il am Ah ee BE A iT GEETE ees Bee Ee HEME NE Y E E E E ENE ESE E O ee ee ESEE ES Thinning out is a simple elimination of the grid currents in metalized regions that can be represented by a smaller number of currents without loosing accuracy As an illustrative example the left half above shows a three resonator filter mapped on th
225. hannel Frequency of the specified path it also has the ability to figure out what the image frequency is up to the 1st mixer The Mixer Image Frequency measurement will show what that frequency is This image frequency is used to determine the area of the spectrum that will be integrated by the this measurement to calculate the image power The Channel Measurement Bandwidth located in the System Simulation Dialog Box is used as the bandwidth for the this measurement For example if we designed a 2 GHz receiver that had an IF frequency of 150 MHz using low LO side injection then the LO frequency would be 1850 MHz and image frequency for all stages from the input to the first mixer would be 1700 MHz If the receiver bandwidth was 5 MHz then the image channel would be from 1697 5 to 1702 5 MHz All noise and interference must be rejected in this channel to maintain the sensitivity and performance of the receiver This measurement is simply a Channel Power measurement at the Image Frequency Values Real value in Watts Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DBM IMGP fs mixer image channel power in dBm Real MAG IMGP _ magnitude of the mixer image channel power in Watts Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DBM IMGP DBM IMGP DBM IMGP MAG IMGP MAG I
226. hannel Power are very useful measurements in SPECTRASYS These measurements give the user the ability to create a user defined channel relative the the main channel The user specifies both the Offset Frequency relative to the main Channel Frequency and the Offset Channel Bandwidth As with the Channel Frequency measurement SPECTRASYS automatically deals with the frequency translations of the Offset Channel Frequency through mixers Both the Offset Frequency and the Offset Channel Bandwidth can be tuned by simply placing a question mark in front of the value to be tuned This measurement returns the integrated Offset Channel Power for every node along the specified path For example if the Channel Frequency was 2140 MHz Offset Channel Frequency was 10 MHz and the Offset Channel Bandwidth was 1 MHz then the OCP is the integrated power from 2149 5 to 2150 5 MHz Tip This measurement is simply a Channel Power measurement at the Offset Channel Frequency using the Offset Channel Bandwidth Values Real value in Watts Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DBM OCP offset channel power in dBm Real MAG OCP magnitude of the offset channel power in Watts Real Examples Measurement Result in graph Smith chart Result on table optimization or yield 179 Simulation 180 DBM OCP DBM
227. hat had an IF frequency of 150 MHz using low LO side injection then the LO frequency would be 1850 MHz and image frequency for all stages from the input to the first mixer would be 1700 MHz If the receiver bandwidth was 5 MHz then the image channel would be from 1697 5 to 1702 5 MHz All noise and interference must be rejected in this channel to maintain the sensitivity and performance of the receiver This measurement is simply a Channel Noise Power measurement at the Image Frequency Values Real value in Watts Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DBM IMGNP mixer image channel power in dBm Real MAG IMGNP magnitude of the mixer image channel power in Watts Real Examples Measurement Result in graph Smith chart Result on table optimization or yield 183 Simulation 184 DBM IMGNP DBM IMGNP DBM IMGNP MAG IMGNP MAG IMGNP MAG IMGNP Not available on Smith Chart This measurement is the ratio of the Channel Noise Power to Image Channel Noise Power along the specified path as shown by IMGR n CNP n IMGNPT n dB where n stage number This measurement is very useful in determining the amount of image noise rejection that the selected path provides For this particular measurement basically two channels exist both with the same Channel Measurement Bandwidth 1 main channel and
228. he 3 sional sources ate created The Tone Spacing determines the spacing between the desired channel and the first interfering tone This same spacing is also used between the two interfering tones Because of this spacing we are guaranteed that intermods will be created in the channel The 2 Tone Power Level is used to specify the actual level of both interfering tones These EIA are shown o in the plot 0 IMA 7 A A Tone Spacing Tone Spacing gt 40 a a UI IO 60 3 0 100 120 20 Power dBm 40 60 Desired Signal 50 100 1 a below Frequency MHZ For the Input Third Order Intercept IIP3 and Output Third Order Intercept OIP3 measurements the 2 Tone Power Level doesn t really matter since these parameters are based on relative measurements However this 2 Tone Power Level is very important when determining the absolute intermod power level and should be set according to the maximum interference levels seen by the circuit For this mode SPECTRASYS will automatically set the channel measurement bandwidth to include all intermod energy This mode is enabled as long the Manual Advanced checkbox is unchecked Mixers Passive and Active Mixers Mixers are key elements in any RF system that translates frequencies like super heterodyne receivers and transmitters Many times their performance is critical to the proper SPECTRASYS System operation of the system
229. he EMPOWER layers for this example are shown below The EMPOWER layers are automatically selected from the available general layers see the previous section They are chosen from the available metal and substrate layers and can be enabled or disabled for EMPOWER simulation 201 Simulation LAYOUT Properties X General Associations General Layer EMPOWER Layers Fonts Height or Tand Rough Surface Imp Curi a Value or File Direx Y ysica TOP METAL 3 Ph en a at ne ne SUBSTRATE 4 Enon w Tand 115 2 2 10 0009 BOT METAL 5 LAYOUT Properties X General Associations General Layer EMPOWER Layers Fonts TOP METAL 3 SUBSTRATE 4 Since Air layers above and below a substrate are so common a special option has been given here to add them For more information on the individual layer options see the EMPOWER Basics section Notice that BOT METAL and Air Below are not enabled This places the box bottom at the lower substrate boundaty so that it acts as a ground plane 202 EMPOWER Operation Note In almost all cases where a completely solid ground plane is used you should use the top or bottom cover to simulate it This is much more efficient than using an extra metal layer Click OK The LAYOUT editor appears The screen should look like similar to yi GENESYS 7 0 O x File Edit View Workspace Actions Tools Layout Synthesis Window Help
230. he model and press OK To place a user defined model and special symbol on a schematic follow the instructions for the More button in the previous section Single Part Models Selecting Add Model Single Part from the Designs Models right click menu displays the dialog box shown below This box defines the underlying part that will be used as the model This dialog is the same as the Change Model dialog box in SCHEMAX The complete process to enter a single part model is 1 Right click the Designs Models icon in the workspace manager and select Add Model Single Part 2 Name the part The system asks if you want to store the file in the model directory When stored in this directory it is easy to reuse the part in other designs 3 Choose a base model The single part model can be based on any part Typically this will be a nonlinear part such as a BJT model 4 Enter the parameters for the part The parameters that you enter will be used as the default for the part 5 Use the part in a schematic Enter a part that has a desired symbol Change it to use your new Single Part model using the Model button on the part dialog Alternately use the More button on the toolbar Then change the model and symbol as prompted 134 User Models One advantage of the single part model is that default values can be easily overridden when used in a design If you are used to Model statements in other simulators single part
231. he pattern that you plan to simulate 5 Do any of the models in the circuit exceed or come close to exceeding the published parameter ranges for SUPERSTAR If so you may want to verify the SUPERSTAR simulation with EMPOWER or use EMPOWER exclusively Most of the models in SUPERSTAR were derived from measured data which was only taken for particular parameter variations The allowed parameter ranges are published for each model in SUPERSTAR Linear or Harmonic Balance This question is the easiest to answer for active circuits you will usually use both For passive circuits filters couplers power dividers etc you will only use linear Passive circuits are linear harmonic balance will not give you extra information that you could not get from linear simulation Active circuits are inherently nonlinear Harmonic balance will help you analyze DC operating points and nonlinear performance For both active and passive circuits linear stimulation is the workhorse of RF design Matching noise and stability studies are all completed quickly using linear simulation Harmonic balance is used to complete the analysis of most circuits Examine mixer conversion gain amplifier compression and detector efficiency using harmonic balance Linear or SPICE Often this question does not have a quick answer For example many engineers associate SPICE with time domain simulation and a linear simulator with frequency domain simulation Actually man
232. here are two ports Each port has two terminals with the bottom terminal generally being ground In the EMPOWER illustration shown on the right the figure the section of line stops before the edge of the box generally one cell width away and a port begins in its place See the Grid discussion in the Basics section to see how this is mapped onto the grid As in the circuit theory schematic there are two ports and each port has two terminals However in EMPOWER instead of the ground plane being modeled as a simple short circuit the effect of currents traveling through the box is taken into account When you first create a port it is automatically configured to be an external port with the proper characteristics to be placed on the end of a transmission line For many applications you will want to modify these characteristics when you place the port These characteristics are shown in the EM Port Properties dialog box which comes up automatically when the port is placed and which can be accessed later by either double clicking on the port or by selecting the port and choosing Details from the Edit menu A typical EM Port Properties dialog box is shown below The following sections describe the entries in this dialog box 241 Simulation 242 EM Port Properties Draw Size This has no effect on the simulation It controls the size that the port number appears on screen and on printouts Ref Plane Shift This parameter is onl
233. ias 43 BASADA 43 HABA Relee aa an 43 HB Noboa 43 HE versan corr tis ie ecusieneiaats 43 Plighest accurate frequency airis 224 Homos Neos nia 283 284 287 Hyperbole aa ac ut sie ee i sctscssaunnen snares aieehe 107 I IF 103 IF THEN GOTO Statement 103 116 ai 107 112 IF I HEN statement iio 112 IF ERUE eint e sins dlehettel daa ce 107 112 A N a a 77 TV EE E E A AEE EEE 107 143 LENS Gs Baa E E P E Ren EE E 107 IMP aoran N a ee eT Re 116 TPE EAN CES usais 36 39 141 247 304 lea O 106 Informational MultipOtt coocccicnnnnnnonnnnnnonncnos 294 PN SW RK E 32 EN Ei id 107 Pte Ser AAA A 106 terra 249 Intermods and Harmonics eccomocccononnnnonanccnnnnnns 73 Inter OdulatiOn eaaa A 43 52 Intermodulation Distortion SPECTRASYS 77 Internal Ports 224 225 250 259 279 288 O a nese 112 DOD E yee as Bie eats 143 A Mote san EE A osuuenedsootncutoued 41 J WACO Dior ae 43 52 53 K K 141 o A nae tan seared 43 53 Simulation 314 L 11301 O A E als Gudenteaarleuts 103 E A E T T nny 217 236 Lts 201 224 239 281 288 LAYOUT Cradle dd 198 O cite E S E E tteaaweeacenvaest 203 A apa mecieeecanenscnne 206 LAYOUT tad 198 203 206 Less ici 106 107 Level DOT rai 86 A A E cere nee te iron 139 Lime Directo seiis no NA 241 Line tipene AAA 236 302 Linear Mao md Edad 143 145 Lincar Measurements ssl 141 incar Simulator 1 10 12 31 Linear Simulation Properties ur 31 incaro Para melo iia 32 NA
234. ident wave 1 f seconds The previous example illustrates the propagation of the wave For simple evaluation of the high and low current density region the time average values of the current density is more practical To obtain this plot switch to Magnitude mode by clicking on the Real button The viewer in this mode is shown below The results are as expected for a transmission line segment The current density is highest at the edges and lowest in the middle Note that the absolute values of the current density at the edges are greatly affected by the grid cell size used A smaller grid cell size increases the edge current density However integrated values of current density are nearly invariable as they should be Mexiner 1972 If the exact current density values are required we recommend choosing a grid cell size equal to the metalization thickness 275 Simulation 276 empower Viewer W6 5 File View xY a Mag Soia Freq GHz 15 l Glololeala Top Front Side Oblique Biel ES 0 232 0 116 0 Amm To investigate the various current components you may switch from the XY mode to the X mode XY X Y Z button You see only a small change in the graph because the current flows primarily along the line segment as expected Note however the component visualiz
235. ield DB AN DB AN DB AN MAG AN MAG AN MAG AN Not available on Smith Chart This measurement is the cascaded gain of the main channel along the specified path The Cascaded Gain is the difference between the Desired Channel Power measurement at the nth stage minus the Desired Channel Power measurement at the input as shown by CGAIN n DCP n DCP 0 dB where n stage number The main channel is defined by the Channel Frequency for the selected path and the system analysis Channel Measurement Bandwidth See the Desired Channel Power measurement to determine which types of sionals are included or ignored in this measurement Values Real value numeric Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DB CGAIN cascaded gain in dB Real 171 Simulation 172 MAG CGAIN numeric value of the cascaded gain Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DB CGAIN DB CGAIN DB CGAIN MAG CGAIN MAG CGAIN MAG CGAIN Not available on Smith Chart This measurement is the cascaded gain of the main channel during the IM3 analysis The Cascaded Third Order Intermod Gain is the difference between the Desired Third Order Intermod Channel Power at the nth stage and the Desired Third Order Intermod Channel Power at the input as shown by CGAINIM3 n
236. ies Models for these parts are based on data supplied by the manufacturers the best source of the latest part information The libraries consist of several workspace files that contain models for a range of parts from each manufacturer You can examine the exact contents of any of the files by simply opening the workspace files which are located in the GENESYS Model directory Most models are represented as a link to a SPICE file The spice files are located in the model directory in their nattve ASCII form This link is transparent to you when you place a model in a schematic To do use a model from the library just enter the base nonlinear model that you would like for example a PNP and then change the model to the desired part using the Model amp ldots button on the part parameter dialog You can use your nonlinear device with four methods e Link to an existing SPICE file e Create a single part model e Create a schematic based User Model e Enter the parameters directly into a nonlinear model on the schematic 123 User Models User models allow the creation of new elements by the user These models behave just as if they were built into GENESYS This capability is one of the more powerful features in GENESYS To create a new model you must generally know three things 1 An equivalent circuit for the model 2 Equations which define the component values in the equivalent circuit 3 The parameters that will be spe
237. igenmodes The incident wave is a harmonic function of time Its magnitude is unity and 1t corresponds both to one Watt instantaneous power and 1 2 Watt time averaged power The initial phase of the incident wave is zero Other eigenmodes of the structure are terminated by their characteristic impedances and are perfectly matched It numerically represents a row of the generalized scattering matrix The internal ports are often locations where lumped elements will be included by GENESYS Parameters of the lumped elements are not required for the EMPOWER simulation Thus internal ports default to 1 ohm normalization In this case the viewer data may not be as useful since the lumped elements are not taken into account by the viewer It is also possible to use an internal port as a source of energy to excite a structure The termination impedance can be specified using the option NI lt n gt In this case the internal inputs are terminated by virtual transmission lines with the specified characteristic impedance The unit incident wave is excited at the specified input Note that if option NI lt n gt is used then the external inputs are also terminated by transmission lines or loads with this impedance after de embedding and transformation into the mode space if necessary If the excitation conditions are defined EMPOWER calculates the scattering matrix S with default or defined normalization first Then it creates an excitation vector A 0
238. igh or low there will be very little power at the input of this filter for this particular frequency that will actually be transmitted through the filter Most of the energy will be reflected by the filter Since the input power to the attenuator is very high and the input power to the bandpass filter is very low then it appears that the entire attenuation of the filter appears across the 3 dB pad In other words the transmitted energy through any filter will be equal to the insertion loss When we realize that the power at each node is the actual power that is transmitted through the element to the next node in the path then the level diagrams make more sense Another way that we can think of this node power is that this would be the actual power measured at that node with a power meter at that given frequency if the power meter was matched to the same impedance as seen by that load circuit Path Spectrum Along every path there are 5 categories of spectrums that every signal will be part of These spectrums are desired undesired noise intermod and total Desired and Undesired Spectrum The definition of Desired Spectrum is spectrum that is traveling in the same direction as the desired path All other spectrum originating from other sources will be present at the node of interest but will be specified as Undesired Spectrum since it didn t originate along the desired path direction Each and every node along the path contains both
239. ight 100 Min 0 Max 0 Min and Max can actually be omitted in this case as there is no frequency parameter range with a DC sweep Note v2 is the voltage at the transistor collector node 2 If the collector is a different node change the 2 to the collector node number Simulation Default Simulation Data or Equations oct DC Bias Optimize Mow Cancel 13 Click on Optimize Now and select Automatic The optimizer will run until it selects the correct values of R1 and R2 to meet the targets When the error in the status window is close to zero press ESC to stop the optimization 14 We then select standard resistor values closest to the optimized values For 1 resistors R1 243 ohms and R2 16 5kohm Double click on R1 and R2 and change resistance to 243 and 16500 respectively Linear Simulation Example Now that we have the transistor verified and properly biased from the previous DC walkthroughs we can add the input and output and verify the input and output match 1 Right click Designs Models and select Add a Schematic Name the schematic Amplifier and click OK 2 Copy and Paste the DC Bias schematic to the Amplifier schematic 3 Press the C key on the keyboard and place capacitor C1 on the transistor collector Enter Capacitance 100 Click OK Press the C key again or the Space Bar and place C2 on the transistor base Enter Capacitance 100 Click OK 10 Walkthrough DC L
240. imulate Allows you to select which layout in the current workspace to simulate Since workspaces can have multiple layouts and multiple EMPOWER simulations you can simulate many different layouts within the same workspace Port Impedance When EMPOWER S Parameter data is plotted on a graph it will be normalized to this impedance Different impedances can be used for each port by separating impedances with commas A 1 Port Device Data File can be used in place of any impedance file to specify frequency dependent or complex port impedances Generalized When this box is checked the impedance for each line as calculated by EMPOWER are used for their terminating impedance See your EMPOWER manual for details on Generalized S Parameters Use ports from schematic Check this box when co simulating with HARBEC harmonic balance nonlinear simulation This forces all sources and impedances to be considered in the simulation Note Be sure to check Use ports from schematic if you will be using this simulation as the basis for a HARBEC Simulation otherwise there will be no nonlinear sources available Electromagnetic Simulation Frequencies Specifies the frequencies at which to run EMPOWER If you have lumped elements in your simulation you can often turn down the number of frequencies here and increase the number of frequencies in the Co simulation sweep specified below Start Freq MHz Specifies the minimum frequency to analyze Stop Fr
241. imulation the analyzer will create an analyzer trace for every node in the system Consequently for systems with large number of nodes the integrated analyzer traces alone can be time consuming if the analyzer properties are not optimized The simulation speed can be reduced by a careful selection of Analyzer Mode settings If large frequency ranges are integrated with a small resolution bandwidth then the amount of data collected will be much larger and the simulation speed will decrease Furthermore enabling the Randomize Noise feature may also slow down the simulation In order to increase the simulation speed with the Analyzer Mode enabled the user can disable the Randomize Noise feature increase the Resolution Bandwidth and or limit the frequency range over which a spectrum analyzer trace will be created See the Analyzer Mode section for additional information Ports The standard input INP and standard output OUT ports are much more flexible than other ports used in GENESYS Sources can be created and managed through the system simulation dialog box Sources can be applied to both input and output ports Functions like Step and Repeat Added Noise and Phase Noise are not available except through the system simulation dialog box 99 Parameter Sweeps 3D graphs in GENESYS require parameter sweeps to generate a third dimension for plotting Parameter Sweeps give you this third dimension by adjusting a tune
242. imultaneous set of nonlinear differential equations No mathematical approach is guaranteed to find a solution to the problem Years of work have gone into HARBEC to develop the most robust strategies available To add a harmonic balance simulation 1 Right click the Simulation Data node on the Workspace Window 2 Select Add Harmonic Balance Simulation 3 Complete the HARBEC Options dialog box For details see the Reference manual To open double click or create a HARBEC Simulation 43 Simulation 44 HARBEC Options General advanced Oscillator Design To Simulate a Signal Sources po Hame Freg MHz Order a 900 5 2 JoscroRT_ 10 5 Maximum Mixing Order 10 Temperature 27 0 ae Maximum Analysis Frequency Calculate Automatic Recalculation AutoSawe Workspace After Calculation Recalculate Now scillator Frequency Search Only Calculate Nonlinear Noise Adds Noise Tone ee me General Tab Design To Simulate Defines the schematic or EMPOWER electromagnetic simulation that will be analyzed If an EMPOWER simulation is selected electromagnetic results will be co simulated with the circuit elements associated with the layout Note If an EM simulation is selected it is very important that the Use Ports from Schematic option be properly checked on the EMPOWER Properties dialog Frequency Table and Order Control Name The schematic desi
243. inal then the viaholes will be accurate at twice the original frequency This procedure can be repeated as necessary EMPOWER Basics E 88542 x10 7 u 12566x 10 3 c OS 10 oy VE Eglg 2 4 Eghy T 10 mils 2 54x 10 m gt 381x10 m e 1935x108 O 2 50 GHz A 3 81x107 m All circuits must contain at least one EMPort to allow data to be taken from the EMPOWER simulation The number of ports is equal to the number of ports in the EMPOWER network to be analyzed They are placed in the layout using the EMPort button and can be Normal deembedded external ports gray external ports with No Deembedding white or internal ports white External Ports and Lumped Elements and Internal Ports are discussed in their respective sections To open double click or create a Planar 3D Electromagnetic Simuation Layout to simulate Fort impedance 50 Generalized Setup Layout Port Modes Use ports from schematic Necessary for HARBEC co simulation Electromagnetic simulation frequencies Co simulation sweep tal iraa val 1o00 M Use EM simulation frequencies stop freq MHz sooo Start freq MHz fice Number of points E Stop freq MHz poo 2 Harber feas E Number of points 5 Max critical freq 3000 W Turn off physical losses faster Recalculate Mow Automatic Recalculation Automatically save workspace after calc OF Cancel Apply Help 225 Simulation 226 Layout to S
244. increasing simulation time as a consequence This change will also change the answer slightly with disastrous results if you are merging data This will not happen if you use MAXFRQ It is also important to remember to update it if you change the frequency range substantially Co Simulation Sweep Specifies the frequencies at which to run simulate the lumped elements EMPOWER data combination If you have no lumped elements in your simulation you should normally check the Use EM Simulation Frequencies box For circuits with lumped elements you can often save much time by using fewer points in the electromagnetic simulation frequencies above allowing the co simulation to interpolate the EMPOWER data before the lumped elements are added Turn off physical losses Faster If checked EMPOWER will ignore any losses specified in the EMPOWER Layer tab This option is very useful to speed up any preliminary runs Automatically save workspace after calc This checkbox is handy for overnight runs to help protect against a power outage Note that checking this box will force the entire workspace to be saved after each run General Viewer Far Field Advanced Generate Viewer Data slower Port number to excite f Mode number to excite f Generate Far Field Radiation Data Sweep Theta Start Angle fo Stop so Step f degrees P Sweep Par Start Angle jo Stop fao Step f degrees OF Cancel Apply H
245. inear HARBEC JE GENESYS V7 5 Amplifier Workspace HB2 R 16500 ohm 4 aS Designs Models 4 4 Select the Input AC Power PAC from the toolbar and place at the end of C2 Double left click on the icon to bring up the dialog box show below Enter the values Designator in Source Frequencies 900 AC Power in as shown below Note Multiple frequencies and corresponding power and phases can be entered by separating the values with semi colons e g 900 910 for 900 and 910 MHz 5 Double click on Source VC Change DC Voltage to VC a variable to be entered in the next step 6 Inthe Workspace Window double click on the Equations node Type VC gt 5 11 Simulation IN gt 40 and close the equations window 7 Place an output at the end of C1 and click OK to select the default values 8 In the Workspace window right click on Simulations Data node and select Add Linear Simulation Accept the default name Click OK 9 Click OK again to accept the default input values 10 In the Workspace Window right click on Outputs node and select Add Smith Chart Name the Graph Match 11 Choose Linear1 Amplifier from the Default Simulation combo box 12 Add S11 and 22 to the measurement list and press OK You will see a Smith chart with input and output match i e S11 22 at 900 MHz This walkthrough continues from the Linear Simulation walkthrough 1 Inthe Workspace Window right click
246. ino load pull contouts sardina 168 Adnet Onne LEOS r ACP oc i ranana 169 Wajacent Channel Prequency ACF U or blas TNR 170 Added Nore CAN ias 170 Cascaded Gn CCALN tica batida 171 Cascaded Gain Third Order Intermod Analysis CGAINIM3 sssseesssesssssssssessesesesrresesese 172 Carrer to Nose Rato EN NT OE 173 Cascaded Nore Figures CNE ienesa ciei arane a ssa shauedhauadundedusundoncudedusdasiadasandiun 173 Channel Or Path Frequency CP ermas a 174 Oee nannel le eguen y OCE iaa 175 Tone Channel Preguen y TEE hiiia E 175 Channel Noise Power ENP auns N 176 Channel Power Chito L77 Desired Channel Power DER ts Als 177 Desired Channel Power Third Order Intermod Analysis DCPIM3 neeesser 178 orse Ghanmel Power OCP a 179 Tone mMinne Po yet GP petarda darias 180 E aU WG erence meee cee een E ner ee ee R ee 180 Gain Third Order Intermod Analysis GAINIM3 ness 181 mass Te CeCe IMOP sacha esse tods 182 mase Ehantel Noise Power 1IMONP area E OA 183 made Nore Rejection Rato MUNI 184 mise Channel Power MED ati d tad ii 184 Image Rejection Rato IMG R nadas 185 Spurious Free Dynamic Rance OPDR ussisaitaiad a ENE SA 186 Smee Dna ne RIN CAS DR aia cater ented AA tata uesemtaeestacs 187 Dare Nose FOE ONP sia 187 Stase Output dB Compression Point SOPIDB ile 188 Stave Output Second Order Intercept GOIPZ acid 189 Stace Cutout Third Order Intercept SOM sti AA A anus 189 Table Of Contents vi Stage Jutp t Saturation Power SOPSA T dad 1
247. insert them into the noise spectrum so that the noise spectrum around signal sources will be accurately represented even through narrow band filters It will do this based on the frequencies of all the known sources in the simulation 3 Additional noise points can be inserted around the channel as specified by the user The user can specify a noise channel bandwidth and the number of points that will be uniformly distributed in this bandwidth Once again this is extremely useful when trying to examine the noise spectrum through narrowband devices like filters etc Smart Noise Point Removal Since the simulation time is proportional to the number of noise points then simulation time can be improved by removing unnecessary noise points For every desired spectrum signal source desired mixer multiplier divider etc product noise points are added at the frequencies specified on the Calculate Tab of the System Simulation Dialog Box Once the noise has been processed by a particular element all noise points are examined to determine their amplitude and phase If consecutive noise points have the same complex values then some of these consecutive noise points are removed Noise sources are not discussed in this section Please refer to the Sources Section for more information about noise sources Note Noise will not be calculated unless the Calculate Noise checkbox in the System Simulation dialog box has been checked Paths
248. ion must be established in otder to make sense of the information contained at the node for viewing a table or a level diagram The value that is reported for a node along a path that has more than two elements is the value seen by the series element in the path entering the node For example in the following example we have defined two paths Path1_2 which is the path from node 1 to node 2 and Path3_2 which is the path from node 3 to node 2 Ona level diagram or in a table the value reported at node 5 for Path1_2 would be the value of the measurement leaving terminal 2 of the resistor R1 entering node 5 Likewise the impedance seen along this path is that seen looking from terminal 2 of the resistor R1 into node 5 Consequently the impedance seen by R1 is the L1 to port 3 network in parallel with the C1 to port 2 network In a similar manner the value reported at node 5 for the Path3_2 would be the value of the measurement leaving terminal 2 of inductor L1 entering node 5 The impedance for the node looking from terminal 2 of inductor Ll is most likely to be completely different from the impedance seen by R1 or even C1 because from the inductors perspective the R1 to port 1 network is in parallel with the C1 to port 2 network SPECTRASYS knows about the direction of all of the paths and will determine the correct impedance looking along that path As a result all measurements contain the correct values as seen looking along the path of intere
249. ique view of the current image This view is top down on the x y plane with a slight offset This option can also be selected by pressing End Rotate The objects in this sub menu rotate the current image Rotate Left Left Arrow Rotates the current image clockwise in a horizontal plane perpendicular to the screen The center of the viewer image window is always the center of rotation Rotate Right Right Arrow Rotates the current image counter clockwise in a horizontal plane perpendicular to the screen The center of the viewer image window is always the center of rotation Rotate Up Up Arrow Rotates the current image forward in a vertical plane perpendicular to the screen The center of the viewer image window is always the center of rotation Rotate Down Down Arrow Rotates the current image backward in a vertical plane perpendicular to the screen The center of the viewer image window is always the center of rotation Rotate Clockwise PgDn Rotates the current image clockwise in the plane of the screen The center of the viewer image window is always the center of rotation This option can also be selected by pressing Page Down Rotate Counter Clockwise PgUp Rotates the current image counter clockwise in the plane of the screen The center of the viewer image window is always the center of rotation This option can also be selected by pressing Page Down Pan The objects in this sub menu shift the ap
250. ircuit contain distributed parts If so linear simulation is a must since SPICE does not include distributed models The electrical transmission line models in SPICE can be used but for final verification of the physical implementation of the lines linear or electromagnetic simulation should be used Often both SPICE and linear simulation are useful in a design For example in amplifier design the linear portion gain matching can be done in SUPERSTAR and the device biasing can be done in SPICE Walkthrough DC Linear HARBEC Note This walkthrough is for customers who have purchased HARBEC for Harmonic balance and DC simulation If you have not purchased HARBEC you can follow the walkthrough given in the SCHEMAX section of the User s Guide which only includes linear simulation The first step is to create a schematic of the transistor with variable collector voltage and base current to verify the transistor IV curves with the manufacturer s published data 1 After starting GENESYS right click on the schematic Sch1 select Rename and change the name to DC Curves Click OK 2 Click Non Linear from the toolbar to open the Nonlinear toolbar select an NPN transistor BIPNPN from Nonlinear BJT s and place in the center of the schematic Double click on the transistor to show the dialog box but leave all values blank We will use an ideal transistor for this example however you can specify a specific model for your ap
251. irst step in creating a SPECTRASYS simulation 1s to create a schematic For this walkthrough we will create the following schematic ISO_1 IL 1 dB fiSO 40 dB 3 dB Resistive Pad VV AAN gt 2 R2 R a ohm lt R 8 5 ohm ATTN_1 m L 2 dB R3 R 141 9 ohm zz we i The following circuit elements are used in this schematic e Input Standard INP on main toolbar or press I e Attenuator on system toolbar e Isolator on system toolbar e Text 3dB Resistive Pad on main toolbar e Resistors on lumped toolbar or press R e Ground and output on main toolbar or press G and O Note Your node numbers may vary from the picture above depending upon how you draw the circuit This simple circuit will illustrate the capability of SPECTRASYS to include lumped elements unlike other types of system simulators Note The walkthrough at this point is saved in Examples SPECTRASYS Walkthrough 1 Create Schematic WSP Next we will add a SPECTRASYS simulation to the workspace To add the SPECTRASYS simulation 1 Right click on the Simulations Data tab in the workspace window 17 Simulation 2 Select Add System Simulation Accept the name System1 3 On the Settings tab change the Measurement Bandwidth Channel to 1 MHz 4 Add a source by ee on the Add button in the source ee system s Simulation Parameters r Mew Custom Source wih n Noise wena 7 sepa and epee Sina 18 Walkthrough SPE
252. is a real function of frequency and is available for 2 port networks only The effective noise temperature is defined in terms of the noise figure NF and a standard temperature To in degrees Kelvin as NFT To NF 1 where To 300 degrees Kelvin Values Real value versus frequency Simulations Linear Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators none Examples Measurement Result in graph Smith chart Result on table optimization or yield NFT noise temperature in degrees Kelvin noise temperature in degrees Kelvin Not available on Smith Chart The Normalized Noise Resistance measurement is a real function of frequency and is available for 2 port networks only The noise resistance is normalized with respect to the input impedance of the network Zo See the definition of Nosie Figure NF for a discussion of Rn Values Real value versus frequency Measurements Linear Simulations Linear Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators none Examples Measurement Result in graph Smith chart Result on table optimization or yield RN noise resistance noise resistance Not available on Smith Chart The reference impedance measurements are complex functions of frequency The measurements are associated with the network terminations The frequency range and intervals are as specified in the Linear Simulation dialog
253. is allows the user to analyze tune and optimize sub networks which are then stored as S parameter data files for use later in other circuit files The S parameter data file written by GENESYS has one line of data for each simulation frequency If there are two or more available simulations or designs in the circuit file GENESYS displays a dialog box to allow you to select the simulation or design to use Some of the data files provided with GENESYS also include noise data used for noise figure analysis This data includes the optimum noise figure NFopt the complex source impedance to present to the device to achieve the optimum noise figure Gopt and the effective noise resistance Rn Example data can be seen in the data file previously shown in Creating New Data Files The best noise figure in a circuit is achieved when the device is presented with an optimum source impedance The optimum input network to achieve this objective does Device Data not in general result in an excellent return loss match Balanced amplifiers and isolators are sometimes used to achieve both the optimum noise figure and a good match Losses in the input network feedback networks around the transistor emitter feedback and multiple stages all effect the noise figure of the circuit All of these effects are accurately simulated in GENESYS using the noise correlation matrix technique 5 6 GENESYS is supplied with a large number of nonlinear parts in its librar
254. is case Manual When checked the manual IIP3 mode is entered and the user must specify the interfering tones as well as a desired signal in the main channel so the correct in channel gain can be determined When unchecked the automatic IIP3 mode is entered and SPECTRASYS will create the two interfering tones and calculate the results Some of the following additional parameters are needed to complete the automatic TIIP3 simulation Tone Spacing automatic and manual This is the spacing between the main channel and the first interfering tone which also happens to be the spacing between the two interfering tones If more that two tones are used manual mode only then this only represents the frequency between the main channel and the first interfering tone Input Port automatic only This is the port number where the two interfering tones will be created Gain Test Power Level automatic only This is the power level of a sional that will be created within the channel to determine the gain of the main channel This particular power level is not that critical However this level should be low enough so that there is no question that the nonlinear devices such as the amplifiers and mixers are operating in the linear range This in channel gain is needed to determine the correct input third order intercept point 2 Tone Power Level automatic only This is the actual power level of both interfering tones System Simulation Paramet
255. ise Broadband Noise SPECTRASYS can process large blocks of spectrum very quickly and broadband noise is no exception Noise can come from any of three different sources These are 1 Thermal noise of passive components 2 Added noise of all components 3 Noise source applied to a port SPECTRASYS uses the parameters found on the Options page and Calculate page of the System Simulation dialog box to determine the frequency range power level and number of points needed to represent the broadband noise In the real world noise occurs at all frequencies Since SPECTRASYS is a continuous frequency simulator we need to provide a way to limit the frequencies of the noise For example the users may not be interested in noise at 10 GHz when looking at an 800 MHz system In other cases this may be necessary The frequency limits for noise are explained below Lower Noise Frequency Limit Is determined by the frequency set by the Tgnore Spectrum Frequency Below parameter The default for this parameter is 0 Hz Upper Noise Frequency Limit Is determined by the frequency set by the Tgnore Spectrum Frequency Above parameter The default for this parameter is 5 times the highest source frequency Thermal Noise Power This power is determined by the System Temperature parameter This noise power is used by all of the elements in SPECTRASYS to create their noise power Obviously the total noise power in a given bandwidth is equal t
256. ith a variety of periodic signals voltage current and power such as single CW tones pulsed waves or dual tones Complex waveforms can be constructed by combining various periodic signals HARBEC makes this through the custom voltage and current sources The two assumptions that harmonic balance uses are 1 the signals in the circuit can be accurately modeled using a finite number of spectral tones and 2 the circuit has a steady state solution HARBEC works by solving Kirchoff s current law in the frequency domain It applies the stimulus sources to the designed network It then searches for a set of spectral voltages that will result in currents that sum to zero at each node and each frequency in the circuit It adjusts the voltage levels a spectrum of voltages at each node through a variety of methods until the sum of the currents is less than a user specified level see Absolute Error and Relative Error on the Harmonic Balance dialog box in the Reference Manual This process of searching is known as convergence The length of time it takes to take a search step is roughly equal to the cube of the product of the number of frequencies and the number of nonlinear nodes Thus if you double the number of frequencies in the circuit you can expect the solution to take roughly 8 times longer However this is only a rough estimate The convergence process is complex and difficult to predict At a fundamental level harmonic balance solves a s
257. ive Dielectric Constants oooocccnoncncnnnnnnes 217 Relative Er e R 43 Relative Peto 217 Relative Tolerance inredare e re 43 52 A O 41 Resistance 141 RESEN een ne NONE Tene ar Tr RURORIC Co 217 RESO iria aria 236 263 283 285 RETURNS ode 103 116 Reverse NO do 139 ROGER a acter EEE 304 Bais cet ee o a oe dl 217 O RA 308 A e O eaters 122 141 O A a a eee 107 O AN 217 O eter eek ase S 110 a O O 304 Simulation 316 S A AA AA 141 145 Sample Expression idos 107 Sample Measures 145 e E A REE E E A A aratcescat cauatsoaeaniags 158 SBL EOE iii 141 SB ZC e E E 141 Scalar matrix combinatlON occocnoccconcccnonnnonnns 110 Semi Infinite Waveguide encsrransiondiodiidaa denia 217 Sd AA A E 38 Setup Modesdialos borras 250 Siena Meral Fie Cts snin n E 285 SPI aro EE A E N 1 A A OA 31 145 Simulation Data adios Elo llo 145 SAA Dd dde 1 Simultaneous match impedance eee 141 Nilo E 107 SiGe PAM model aE 51 134 SUN a ERA T E E 107 O N OEEO 236 237 Sita sn 32 39 141 143 145 A aime 250 301 304 Solid Wire button tido 265 273 A a AR 93 EIT OTE E indicio 10 35 120 122 o A A 141 147 302 Special Opos ieee 43 Special O lid 90 SPEC TRASIS ui dirias 17 SPECTRASYS Broadband Noise eesse 81 SPECTRASYS Channel Frequency 69 SPECTRASYS Cohereney icra cisterna ccs 71 SPECTRASYS Composite Spectrum 88 SPECTRASYS Creating a Schematic 17 SPECTRAS YS TIPS DistoniOni teicicsastscenesrn
258. l To explain it we start from the pseudo non equidistant grid of currents formed for the filter and shown above Instead of 296 EMPOWER Theory complete elimination of the currents inside the enlarged grid cells we leave some of them to keep metal surface solid Those currents left are also replaced with just two variables by means of linear re expansion The solid model is more correct but gives a larger number of variables for similarly thinned out problems in comparison with the wire model The solid model is actually a way to form a non equidistant grid with the grid function re expansion in a discrete space The GGF matrix of a symmetrical problem could be reduced to a centrosymmetrical matrix with centrosymmetrical blocks in the case of two plane symmetry and it is treated in the way similar to described in Weeks 1979 This reduces required CPU memory from 4 to 16 times serial allocation of partial matrices and speeds up calculations from 4 to 16 times One plane two plane and 180 rotational symmetries are included in the program Thereafter the classic Gauss inversion algorithm is used with a few changes The result of this stage of solution is a matrix Y or Z matrix relating the grid currents and voltages in the input source regions and thus we need to get only a small part of the inverted matrix corresponding to these variables A partial inversion procedure performs it and gives an additional acceleration The m
259. l settings for a SPECTRASYS Simulation To reach this page add a System Simulation by right clicking on Simulations in the Workspace Window Tip Any of the parameters in this dialog box can be made tunable by placing a in front of the parameter system piles Parameters E i i Meson Bandwidth dE o a ape vam must enter the channel bandwidth here before simulation P e E ROA Description y A E E Design to Simulate The schematic to use for the system simulation Channel Measurement Bandwidth Specifies the integration bandwidth of the all channels used in SPECTRASYS SPECTRASYS System Nominal Impedance The default system impedance Recalculate Now Closes this dialog and initiates an immediate recalculation of the system simulation Automatic Recalculation When checked enables SPECTRASYS to automatically recalculate the simulation on an as needed basis Sources Grid that defines the system simulator signal sources Name Name of the signal source Port Port to attach the signal to Note that more than one signal can be present at a port Description Description of the signal source Enable Enables disables the source in the system simulation Add Add a new soutce Edit Edit the current soutce Delete Delete the current soutce Factory Defaults Will restore the factory default values and options for the system analysis System Simulation Parame
260. lating numerical derivatives when the nominal parameter value is zero Default value is 1e 10 HARBEC DC amp Harmonic Balance HARBEC Options General Advanced Oscillator Note You must have an oscillator port on the schematic to use these Features Initial Frequency Minimum Search Frequency 1e 3 MHz Maximum Search Frequency 1000 MHz Number OF Points 1000 C Use Oscillator Solver f Use Oscillator Port Frequency And Amplitude As Specified Edit Oscillator Port Frequency not Found Amplitude 0 1 Y Display Spectrum 4nd Waveform Graphs OK Cancel Help Oscillator Tab Initial Frequency Find Initial Oscillator Port Frequency Calculates and fills in the frequency of oscillation for an oscillator port in the schematic using a linearization frequency dependent Y matrix of the nonlinear response of the circuit Minimum Search Frequency The smallest frequency to search for the frequency of oscillation Maximum Search Frequency The largest frequency to search for the frequency of oscillation Number of Points the number of frequencies in the above range linearly spaced to search for the frequency of oscillation Harmonic Balance Calculation Options 49 Simulation Use Oscillator Solver Perform nonlinear calculation of oscillation frequency then use that frequency for HarBEC simulation Use Oscillator Port Frequency and Amplitude as Specified Use frequenc
261. layer instead should be used The Bottom Cover should be set to Lossless type and the Top Cover should be set to Electrical type with surface impedance set to 377 ohms General Viewer Far Field Advanced e Generate Viewer Data slower Port number to excite f Mode number to excite 1 w Generate Far Field Radiation Data e Sweep Theta Start Angle jo Stop fiso Step f degrees W Sweep Phi Start Angle fo Stop fao Step f degrees Cancel Apply Help Specifying Sweep Parameters In order to generate far field radiation data Generate Viewer Data slower and Generate Far Field Radiation Data must be checked You may then select either Theta Phi or both to be swept Data is generated for all points between Start Angle and Stop Angle for both Theta and Phi with a step size specified in the Step field All angles are in degrees In the above figure data is being generated sweeping both Theta and Phi Theta is being swept from 0 to 180 degrees in 1 degree increments while Phi is being swept from 0 to 90 degrees also in 1 degree increments 271 Simulation 272 Measurements and Plotting Once far field radiation data is generated the following measurements can be plotted ETHETA phxis thetas freqs the theta component of the total electric field Phzs Thetas and fregs can either be single values or ranges of values EPHI pAis thetas freqs the phi component of the total e
262. lculate IIP3 TOD section for information on how to configure these tests See the Desired Channel Power Third Order Intermod Analysis measurement to determine which types of signals are included or ignored in this measurement In the Calculate WP3 TOD Manual Mode since a dedicated IM3 analysis is not created and the normal analysis is also the IM3 analysis pass Remember intermod bandwidth is a function of the governing intermod equation For example if the intermod equation is 2F1 F2 then the intermod bandwidth would be 2BW1 BW2 Note Bandwidths never subtract and will always add The channel bandwidth must be set wide enough to include the entire bandwidth of the intermod to achieve the expected results The Automatic Intermod Mode will set the bandwidth appropriately Values Real value in Watts Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DBM GIM3P generated third order intermod power in dBm Real MAG GIM3P magnitude of the generated third order intermod power in Watts Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DBM GIM3P DBM GIM3P DBM GIM3P MAG GIM3P MAG GIM3P MAG GIM3P Measurements SPECTRASYS Not available on Smith Chart This measurement is the integrated total intermod power conducted from the prior stage plus the intermod power gener
263. le One of the easiest ways to get nonlinear device models into GENESYS for use with HARBEC is to use a link to a manufacturer supplied SPICE file SPICE files have the following advantages over other methods of using nonlinear device data e They are often supplied by manufacturers e Entering device data manually is tedious and error prone e SPICE files often contain very complete macromodel device characterizations They also have a few disadvantages e Model parameters cannot be tuned directly in GENESYS e SPICE data provided by manufacturers are often intended for low frequency use and may not adequately characterize high frequency behavior This is generally not a problem for devices intended for use at high frequencies To create a link to a SPICE file 1 If workspaces using the spice link will be shared with co workers then we recommend placing the spice file either on a network drive which has the same letter for all co workers or better into your GENESYS model directory or a subdirectory there 2 Right Click on Designs in the Workspace Tree and select Add Link to SPICE File 3 If you want this link to be available automatically everytime you start GENSYS you should answer Yes and then save your file into the model directory 4 Click the button on the SPICE Link dialog box and choose your spice library from the browse box Press OK 5 Choose the desired model or subcircuit from the combo box 6 Normal
264. lectric field Phzs Thetas and fregs can either be single values or ranges of values ETOTAL phxs thetas freqs the magnitude of the total electric field Phzs Thetas and fregs can either be single values or ranges of values ELHCP E field Left Hand Circular Polarization ERHCP E field Right Hand Circular Polarization EAR E field Axial Ratio The measurement wizard can be used to to select these measurements and the proper syntax is automatically generated Rectangular Antenna Polar and 3D charts may be generated to display the antenna data Only one variable out of Phi Theta and Frequency may be swept when displayed on the two dimensional charts and two variables may be swept when displayed on the 3D chart Below is both a rectangular and Antenna plot polar of the ETOTAL measurement where Theta is being swept from 0 to 360 degrees Phi is held constant at 0 and the frequency is held constant This particular antenna is a very small dipole located one wavelength above a ground plane on top of a substrate EMPOWER Viewer and Antenna Patterns E Graphi Workspace infpole_Subst th Lk fh of Ree ty RENETI RE te eee Lael ge MOR ee wieg bi gt Fido DB ET otago DB ETota 0 Examples This section illustrates the use of the EMPOWER viewer using a number of examples The WSP files for the examples are located in the subdirectory PROGRAM FILES GENESYS EXAMPLES VIEWER You may load them as
265. length in the direction of propagation along the line and width is the width of the strip Layer Specifies the metal layer on which the port is placed Location specifies the edge of the port for external ports and the center of the port for internal ports Line Direction Gives the direction of the line at the port In the default mode the nearest wall determines the direction of the line This value rarely needs to be overridden Current Dir Specifies the direction of current flow within the port The first figure below shows the default current direction for external ports on strip type structures such as EMPOWER External Ports microstrip and stripline The second figure shows the default current direction for external ports on slot type structures such as coplanar waveguide For internal ports the default current direction is Along Z This value also rarely needs to overridden strip conductors Pe a ae 0 di 0 A Along Y B Along X Port Type Specifies the basic type of port Normal No Deembed and Internal e Normal ports are external ports which are deembedded and may be multi mode They are shown in gray on the layout e No Deembed ports are external ports which are not deembedded and cannot be multi mode They are shown in white on the layout e Internal ports are also not deembedded and cannot be multi mode They are shown in white on the layout For mote information on dembeddi
266. lerance Range This threshold range is used by some elements in SPECTRASYS to warn the user when a given power level falls outside SPECTRASYS System the specified range This range applies to each element on a case by case basis For example the total LO power for the given mixer will be determined by integrating the LO spectrum and then comparing this power level to the LO Drive Level for the given mixer If this power level is outside the Tolerance Range window then a warning will be issued for this mixer either indicating that the mixer is being starved or over driven Note All parameters on this page will support equations and can also be made tunable by placing a question mark in front of the parameter value Amplifiers Amplifiers This section will describe the fundamental operation of how SPECTRASYS simulates RF amplifiers General RF and VGA Variable Gain Amplifier Parameters Gain Small signal low frequency gain The actual amplifier gain will change according to the gain compression and frequency rolloff of the amplifier Noise Figure Amount of noise added to the circuit by the amplifier The noise figure 1s assumed to be flat across frequency A time domain simulation is performed to determine the noise figure If the amplifier is in compression Output P1dB Output 1 dB compression point Output Saturation Power Output saturated output power Output IP3 Output third order intercept Output 1P2 Output s
267. les of microwave Circuits McGraw Hill Co New York 1948 O Heaviside Electromagnetic theory AMS Chelsea Publishing Co New York 1950 A A Samarsku A N Tikhonov About representation of waveguide electromagnetic fields by series of TE and TM eigenwaves in Russian GTF Journal of Theoretical Physics 1948 v 18 p 959 970 P I Kuznetsov R L Stratonovich The propagation of electromagnetic waves in multiconductor transmission lines Pergamon Press Oxford 1964 originally published in Russian 1958 K S Yee Numerical solution of initial boundary value problems involving Maxwell s equations in isotropic media IEEE Trans v AP 14 1966 p 302 307 V V NikoPsku Variational approach to internal problems of electromagnetics in Russian Moscow Nauka 1967 J Meixner The behavior of electromagnetic fields at edges IEEE Trans v AP 20 1972 N 7 p 442 446 B V Sestroretzkty RLC and Rt analogies of electromagnetic space in Russian in Computer aided design of microwave devices and systems Edited by V V Nikol sku Moscow MIREA 1977 p 127 128 T Weiland Eine Methode zur Losung der Maxwellschen Gleichngen for Sechskomponentige Feleder auf Dikreter Basis Arch Electron Uebertragungstech v 31 N 3 1977 p 116 120 Computer aided design of microwave devices in Russian Edited by V V Nikol skii Moscow Radio 1 Sviaz 1982 R H Jansen The spectral domai
268. limits For example If we had a 2 GHz transmitter that had an IF frequency of 150 MHz and we set the Ignore Frequency Below limit to 200 MHz then the entire IF signal would not be present and consequently neither would the 2 GHz RF signal Level Below default 200 dBm All spectrums that are below this threshold will not be created by SPECTRASYS This threshold should be set to the highest acceptable level if optimal speed is an issue Spectrums are not actually ignored if they are not more than about 20 65 Simulation 66 dB below this threshold since several spectrums can be added together to give a total result that would be greater than this threshold Frequency Below default 0 Hz All spectral components whose frequency is below this threshold will be ignored and will not be created Spectrums falling below this limit will not continue to propagate However there are several cases where negative frequencies may be calculated at interim steps i e through a mixer which will be folded back onto the positive frequency axis This parameter will only affect the final folded frequencies and not the interim frequency steps Likewise this is the lower noise frequency limit Frequency Above default 5 times the highest source frequency All spectral components whose frequency is above this threshold will be ignored and will not be created Spectrums falling above this limit will not continue to propagate Likewise this is
269. llowed in model names so it is important to use the underscore character _ as shown It is next to the zero on most American keyboards with shift 5 The following dialog appears me you want to save E an a inte nthe GENESYS e ae le seacle70 MODEL iG Marie If a workspace ts put into the model directory then tts models and functions are loaded automatically when GENESYS starts 6 Ifyou answer Yes to this dialog GENESYS will automatically load the model in the future making it available for quick use 7 Inthe Model Properties dialog enter the following information User Models Model Properties El Parameter meseta Jas gt aje pactar Guelty factor ee Cn O O TA Cr O O TN Cao IO IO TN O ome a Note In GENESYS 6 0 all parameters are converted to GENESYS standard units before being passed into your model They are the ones shown on the units combo box NL nonlinear units are a convenience when Using nonlinear devices which are generally specified using fundamental units Layout Association CAP Symbol Cancel Help This box lists the parameters which must be passed to the model whenever it is used The parameters for this example are C the actual capacitor value FO the frequency at which the capacitor self resonates Q the quality factor of the capacitor The Layout Association box associates this model with a normal capacitor when choosing footprints for board l
270. log box When EMPOWER is run it outputs a file in the structured storage when run from GENESYS for each port with impedance data with extensions R1 R2 R3 etc so for a 2 port network in file EMPOWER analysis EM1 using Generalized impedance is 247 Simulation equivalent to using an impedance of WSP Simulations EM1 EMPOWER R1 WSP Simulations EM1 EMPOWER R2 See the examples manual an example of the use of generalized S Parameters 248 EMPOWER Decomposition In EMPOWER it is possible to break down large circuits into smaller segments which are connected by transmission line sections Decomposition can be tedious to implement but its reward is that simulations can be performed accurately in much less time and with fewer frequency points The principal benefits of decomposition are e Ability to tune single or coupled transmission line sections inside a circuit which was simulated by EMPOWER For example you can change the size of a meander line or adjust the tap point on an interdigital filter without rerunning the EMPOWER simulation e Most circuits require far fewer frequency points for accurate analysis This is due to the fact that quarter wave resonant lines are broken down into much smaller lines that do not resonate and interpolation is possible For example a 7th order interdigital filter can often be simulated with just 5 frequency points in the EMPOWER run while 100 points are displayed in the output sw
271. losa l BB10c 18 71 A Az Esq Designs HE 3 fie Layout Layo 29 Simulations Data 23 Outputs EE Equations Drawing the Layout To draw the seties line 1 Select the Rectangle button from the LAYOUT toolbar This is the third button on the bottom toolbar 2 Click on the left edge of the page border and drag toward the right and down until the status bar shows DX 425 and DY 50 3 Release the mouse button This is the series transmission line The screen should now look as below Don t worry if the line isn t at the exact same position on the page the layout will be centered later 203 Simulation BE Layout ei WorkSpace 1 To draw the open stub 1 Select the Rectangle button from the toolbar 2 Click at the bottom edge of the line just drawn one grid cell left of the series line s center 3 Drag to the right and down until the status bar shows DX 25 and DY 225 4 Release the mouse button The screen should now look like the following If the stub line isn t centered horizontally on the screen select the stub by clicking on it and drag it to the proper position 204 EMPOWER Operation E Layout Workspace WorkSpace 1 As a general rule EMPOWER simulation time is greatly reduced if the circuit to be simulated exhibits symmetry in any of several planes Many circuits will exhibit some form of symmetry if they are centered in the page area To center the example filter 1 Choo
272. lways requests these files when EMPOWER is tun from GENESYS Notes These files are numbered differently than Ln files When these files are numbered each port in a related group of ports is counted individually Written by EMPOWER Type Binary Can be safely edited No Avetage size 1 to 5Kbytes but may be larger Use Internal file for EMPOWER but can also be used in the SMTLP and MMTLP models in GENESYS These files are used in place of Ln files if a filename was given on the PORT line in the TPL file When run from GENESYS this file type is not available use the Ln files instead Otherwise they are completely identical to the Ln files described earlier Written by User Type Text Can be safely edited Yes Average size 1 Kbyte Use Specifying electrical losses These files are used to specify the impedance of conductors in ohms per square These files are used in the EMPOWER layers setup dialog box or in the TPL file The files are formatted just like RX files in GENESYS Written by EMPOWER Type Text Can be safely edited Yes Average size 5 to 50 Kbytes but may be larger Use Contains S Parameter data calculated by EMPOWER This file contains the S Parameter data written by EMPOWER It is in the industry standard S2P format and can be loaded into most RF and Microwave simulators Even though these files can be edited they will be overwritten whenever EMPOWER is rerun Written by User or GENESYS Type Tex
273. ly the only other necessary change in this box is checking or unchecking Reverse Nodes 1 amp 2 This box tells GENESYS that the spice subcircuit uses the spice node numbering convention Input 2 Output 1 Normally you will check this box if the data represents a transistor or amplifier 7 Click OK 8 Generally you should allow GENESYS to rename your model to be the same name as the spice model to avoid confusion 137 Simulation 138 Note GENESYS will not allow 2 models with the same name to be loaded If you create a SPICE model with the same name as an existing part GENESYS will give an error at startup If this happens simply load your workspace and rename the spice link To use a link to a SPICE file 1 Ona schematic place a part with the symbol you want for the link For example if you are placing a Bipolar Transistor place a bipolar symbol 2 Double click on the part 3 From the Schematic Element Properties Dialog box click the model button 4 From the Choose Model dialog box choose the file and model with the spice link Click OK and Click OK GENESYS is compatible with Berkeley SPICE3 Where possible GENESYS has also been made compatibile with PSpice The following devices can be used in a SPICE link B Arbitrary Source Note SPICE 2 uses B for MESFET s If you have a file using this convention you must change the B prefix to Z and change the model name from MESFET to NMF or PMF C Capacito
274. m due to all of the signals arriving at the RF input intermods and harmonics are created Both the sum and difference spectrums will be created from this non linear spectrum and the peak LO spectrum frequency Any negative frequencies created during the difference calculations will be shifted by 180 degrees and folded back onto the positive frequency axis For all signals traveling from the RF port to the IF port the IF port amplifier is effectively bypassed The non linear spectrum created by the internal amplifier on this port will also appear on the input port and be propagated backwards due to the reverse isolation of the mixer It is assumed that the reverse isolation of the mixer is equivalent to the RF to IF isolation Signal Spectrum Arriving at the IF Port Spectrums will be treated identically to the RF port except for the fact that the amplifier on the IF port is used to create the non linear spectrum appearing at the IF port input and the amplifier on the RF port will be bypassed Mixer LO Level Warning Maintaining proper mixer LO level is important to guarantee the performance of any mixer Typically this is a level that can easily be overlooked from one design turn to another The user must specifically check the LO power level to ensure that the mixer is operating in the expected range With SPECTRASYS this process is much easier and the user will automatically be notified if the mixer is being over or under driven The user has con
275. me metal layer as the resistor pads Note EMPOWER planar ports cannot be used for ground referenced elements such as transmission lines even though the element might only have terminals Add extra details to listing file If checked extra information which can be used to double check your setup is inserted into the listing file Show detailed progress messages Turning this option off suppresses almost all output in the EMPOWER log The listing file is not affected Turning it off can dramatically speed up very small runs Command Line Some options are available which are not shown on this dialog box One common example is the Oz option which controls the size of the box for line analysis 229 Simulation NC If this option is used EMPOWER will allow de embedded ports to be away from the wall This option is especially useful for finline and slotline configurations VM Allow virtual memory usage To solve a complex problem EMPOWER always limits usage of computer virtual memory hard disk space in a rational way It will not use 1t for some numerically intensive parts of the simulation The option VM tells EMPOWER to use virtual memory more freely But even with this option the program stops calculations if substantial hard disk space is involved in some parts of the simulation Check the MEMORY lines in the listing file to have an idea how much memory your computer lacks or how to reduce the problem Sg Use an
276. models allow you to follow this paradigm while giving more flexibility age Mae Category Builtin Microstrip New Modet E Caca Text Model Definitions Note The preferred method for creating models is to use the schematic based model editor described in User Model Example A Self Resonant Capacitor If you do not have SCHEMAX you may create a text description of your models The format is as follows MODEL name parm parm2 model equation lines model description lines DEF2P nodel node2 noden name where name is the name of the model parm ate the parameters specified by the user model equation lines contain the equations for the model model description lines contain elements which make up the model nis the number of external nodes on the model node ate the external nodes used in the model descriptionlines The text equivalent for the model given in GENESYS Model Varactor wsp is MODEL VARACTOR Vt Co Gamma Lp Cp Q Cv Co 1 Vt 0 7 Gamma C4 Co 1 4 0 7 Gamma Rs 1 3 14168e8 C4 1E 12 Q CAP 1 2 C Cv RES 2 3 R Rs CAP 1 3 C Cp IND 3 4 L Lp DEF2P 1 4 VARACTOR This model can be typed or copied into a text file You must then edit the Default mod file in the GENESYS BIN directory Add the line LIBRARY filename where filename is the complete path and filename of your model It can then be used as follows 135 Simulation VARACTOR nl n2 V x Co x G x Lp x Cp x Q x 136 Link to Spice Fi
277. n approach for microwave integrated circuits IEEE Trans v MTT 33 1985 N 10 p 1043 1056 S G Vesnin Electromagnetic models for design of microstrip microwave structures in Russian Ph D Thesis MPEI Moscow 1985 E F Johnsom Technique Engineers the Cavity Resonance in Microstrip Housing Design MSN amp CT 1987 Feb p 100 102 107 109 J C Rautio R F Harrington An electromagnetic time harmonic analysis of shielded microstrip circuits IEEE Trans v MTT 35 1987 N 8 p 726 730 307 Simulation 308 B V Sestroretzkiy V Yu Kustov Electromagnetic analysis of multilevel integrated circuits on the base of RLC networks and informational multiport approach in Russian Voprosi Radioelektroniki ser OVR 1987 N 1 p 3 23 L P Dunleavy P B Katehi A generalized method for analyzing shielded thin microstrip discontinuities IEEE Trans v MTT 36 1988 N 12 p 1758 1766 T Uwaro T Itoh Spectral domain approach in Numerical techniques for microwave and millimeter wave passive structures Edited by T Itoh John Willey amp Sons 1989 R H Jansen Full wave analysis and modeling for CAD of mm wave MMICs Alta Frequenza v LVIII 1989 N 5 6 p 115 122 A Hil V K Tripathi An efficient algorithm for the three dimensional analysis of passive microstrip components and discontinuities for microwave and millimiter wave integrated circiuts IEEE Trans v
278. n make tradeoffs of speed versus accuracy Amplitude Stepping To start the search for convergence HARBEC analyzes the circuit at DC this is with all independent AC signal turned off Using DC as a first guess it turns on the signals to Maximum Amplitude Step percentage of full signal If convergence is reached at this step it takes another equal step If convergence is not reached it decreases the step size and tries at the lower signal level Some circuits will converge in a single 100 step Others will require a smaller step to find the solution If a smaller step is required it will be faster to start with that step If the step size is too small the simulator may waste time calculating intermediate steps to find the final solution Convergence speed can be improved by setting Maximum Amplitude Step to the ideal step Krylov Subspace Iterations When the Jacobian matrix gets very large it can become very slow to calculate and use Krylov subspace iterations can dramatically reduce the size of the matrix and thus speed up calculations of very large circuits In general however Krylov will have more convergence issues than full Jacobian steps Also for smaller circuits Krylov may be slower than full Jacobian steps For very large problems try selecting Krylov to reduce memory requirements and speed convergence SPECTRASYS System Linear Y matrix models are created from the behavioral models in SPECTRASYS These Y matrix m
279. n place The frequency range and intervals are as specified in the Linear Simulation dialog box A port number 7 is used to identify the port VSWERz is the Voltage Standing Wave Ratio looking in from port z The VSWR is a measure of the energy reflected back to the port The VSWR is related to the s parameter S11 by VSWR 1 Su 1 Su Therefore as the reflected energy goes to zero S11 goes to zero and the VSWR approaches unity As the reflected energy increases S11 approaches unity and VSWR goes to infinity Values Real value versus frequency Simulations Linear Default Format Table RE Real Graph RE Real Smith Chart Sj plots s parametets Commonly Used Operators None Examples Measurement Result in graph Smith chart Result on table optimization or yield VSWR1 VSWR1 VSWR Measurements Linear VSWR Show VSWR for all ports Not available on Smith Chart plots s parameters The port impedance and admittance measurements are complex functions of frequency The measurements are made looking into the network from the port with other network terminations in place The frequency range and intervals are as specified in the Linear Simulation dialog box A port number 7 is used to identify the port ZIN7 is the input impedance looking in from port z YINz is the input admittance looking in from port 2 Values Complex value versus frequency Simulations Linear Default Format Table
280. n the right portion of the chart low impedances on the left portion inductive reactance in the upper half and capacitive reactance in the lower half Real impedances are on a line from the left to right and purely reactive impedances are on the circumference The angle of the reflection coefficient is measured with respect to the real axis with zero degrees to the right of the center 90 straight up and 90 straight down The impedance of a load as viewed through an increasing leneth of lossless transmission line or through a fixed length with increasing frequency rotates in a clockwise direction with constant radius when the line impedance equals the reference impedance If the line and reference impedances are not equal the center of rotation is not about the center of the chart One complete rotation occurs when the electrical length of the line increases by 180 Transmission line loss causes the reflection coefficient to spiral inward The length of a vector from the center to a given point on the Smith chart is the magnitude of the reflection coefficient The angle of that vector with respect to the real axis to the right is the phase angle of the reflection coefficient Several common definitions are used to represent the length of this vector They are referred to as radially scaled parameters because they relate to a radial distance from the center towards the outside circle of the chart HARBEC DC amp Harmonic Balance DC
281. ndow to open the system simulation 2 Click the Edit button at the end of the row where the CW source is located 22 Walkthrough SPECTRASYS EX Simulation Parameters General T Paths Calculate Conposte peta Opens po Measurement Bandwidth th AA o tee 4 o de Sees ee A A de a del Channel aj E E no po Es bE Youn must enter the e channel bandwith here before simon A of R 8 Type a in front of the 50 for the source power The power of the source should ae like 50 Click OK to close the source dialog box Type 1 question mark followed by 1 in the channel measurement bandwidth Click OK to accept the changes to the system simulation Double click Output Spectrum in the workspace window to open the output spectrum Tune the input power and bandwidth Try tuning the resolution bandwidth to 3 MHz and the input power to 0 dBm This will allow you to see a good picture of the resolution bandwidth It also clearly distinguishes the power coming from the input containing a signal and the power coming from the output containing only noise Note The walkthrough at this point is saved in Examples SPECTRASYS Walkthrough 4 Tuning Parameters WSP Add an Amplifier Let s add an amplifier to this circuit Modify the schematic to look like the following Don t forget that you can hold Alt down while moving the output to break the connection to the resistor The RF Amplifier i
282. nductor this allows the size of the spiral and the inductance to be tuned or optimized in GENESYS e Far fewer points need to be analyzed This is because each of the pieces is simpler and interpolation works well For example in the edge coupled filter each of the pieces contain only open ends and small sections of lines which do not resonate As a result this filter only needed 5 frequency points for a good analysis e With any of these circuits The grey areas can easily get so large that the problem requires hundreds of megabytes to analyze In the meander line if the lengths of the coupled lines grey areas gets very long the EMPOWER simulation could take a long time When the circuit is decomposed simply changing one length value in GENESYS gives a virtually instant analysis no matter how long the coupled sections are Spiral Inductor Example As a first decomposition example we will analyze a spiral inductor The first step is to come up with a plan for decomposition as shown here We strongly recommend that you write a similar plan on paper when you setup a problem for multi mode analysis 250 EMPOWER Decomposition Part Part The first step is to create workspace with a layout for each unique piece In this example there are two unique pieces The lower left corner is the first and each of the other three corners which are identical There are two basic methods for creating these pieces e Create the pie
283. ng and multi mode lines see below If you are actually building your circuit in the same style as an EMPort that is if your ports consist of a line which stops just short of the end wall as is often the case with a coax mictostrip junction then you may not need to use deembedding because EMPOWER is simulating the circuit as you are actually going to build it 243 Simulation 244 However you may not have this kind of construction or you may be simulating a small segment of a larger circuit In an external port there is capacitance at the port due to coupling from the open end of the line to the wall Deembedding removes this extra reactance perfectly matching the transmission line modeling it as though the line and box extend out to infinity Deembedding also allows you to define a reference plane shift By default the reference plane shift is zero which means that the resulting data is measured at exactly the side wall If the reference plane shift is negative then the data is measured from inside the box effectively subtracting length from the circuit If the reference plane shift is positive then the data is measured from outside the box effectively adding length to the circuit RefShift RefShift CIRCUIT JA This is the equivalent network used when deembedding 1s active The center of the figure labeled CIRCUIT contains the raw results from the EMPOWER simulation Reactance X shown as inductors above c
284. ng at currents in the viewer is a great way to get insights into circuit performance However generating this viewer data requires additional time increasing the length of a run by a factor from two to ten and sometimes requiring additional memory also Generating viewer data has no effect whatsoever on the solution given so you should not have this option turned on unless you actually intend to run the viewer You can turn this option on and off by using the checkbox labeled Generate Viewer Data Slowet when starting an EMPOWER run You will not normally need viewer data and when it is needed you will not normally need viewer data at every frequency Our recommendation 1 Run all problems the first time without generating viewer data If the answer is completely unexpected check for errors in your description of the file This can save a lot of time in the experimenting stage 2 If you decide you want viewer data open the EMPOWER Options dialog box Reduce the number of frequency points to be analyzed and turn on Generate Viewer Data Slower Recalculate the EMPOWER simulation and you will now have viewer data at some points 3 If your problem is very large you may want to increase the cell size or make other tradeoffs to reduce the time required for calculation If you use this technique save the file with a new name before you generate viewer data so that you do not corrupt your existing S Parameter data See the EM
285. ng out slower accurate M Use planar ports for one port elements MT Add extra details to listing file e Show detailed progress messages Command line 213 Simulation Click the Recalculate Now button If anything has been modified since the last EMPOWER run this launches EMPOWER to simulate the layout Note EMPOWER has been given a lot of intelligence to determine when it needs to calculate Clicking Recalculate Now will not do anything if EMPOWER believes it is up to date To force EMPOWER to recalculate from scratch right click on the electromagnetic simulation in the workspace window and select Delete all internal files Once EMPOWER calculation is completed GENESYS displays the calculated data The eraphs below show GENESYS after EMPOWER simulation Double click the graph items in the workspace window to open them and select Tile Vertical from the Window menu to organize them 4 GENESYS 7 0 dl x File Edit View Workspace Actions Tools Synthesis Window Help Osa ae arena a am gt z ca tty po a Designs 16 F2000 Schema Layout Layout 15 a 3 Simulations D ata Sij EM1 Layout eS Linear 1400 tc 0 3 Outputs 18 21 AH Circuit Simulatior ar HA Combined Simul S Equations 8 3 Substrates E 07 i pe Er Default 24
286. ngs up the multi mode setup dialog box as described in the Decomposition section of your EMPOWER manual If this button has exclamation points on it then multi mode lines are active Thinning out slider Control the amount of thinning The default thinning out amount is 5 Setting the slider to zero turns off thinning See your EMPOWER manual for details on thinning Thin out electrical lossy surfaces If checked lossy metal described using electrical parameters will also be thinned Since the thinning out model assumes that most current flows on the edges of the lines this option will be somewhat less accurate for resistive films where current flows more evenly throughout the material In these cases you should probably also check the Solid thinning option shown below Solid Thinning out slower If checked slower solid thinning out model is used This model restores capacitance lost due to thinning out and can be most useful for when large sections of metal have been thinned out Use planar ports for one port elements This box should almost always be checked When not checked EMPOWER uses z directed ports at each terminal for all devices When it is checked EMPOWER uses in line ports for elements like resistors and capacitors two terminal one port devices The only time this can cause a problem is when you have a line running under an element for example running a line between the two terminals on a resistor in the sa
287. nly Used Operators None Examples Measurement Result in graph Smith chart Result on table optimization or yield Measurements SPECTRASYS IMGF IMGF IMGF Not available on Smith Chart This measurement is the integrated noise power of the image channel from the path input to the first mixer After the first mixer the Mixer Image Channel Power measurement will show the same noise power and the main channel noise power This measurement is very useful in determining the amount of image noise rejection that the selected path provides Any energy at the image frequency can seriously degrade the performance of a receiver Even unfiltered noise at the image frequency will be converted into the IF band and degrade the sensitivity by as much as 3 dB The image frequency measurements are provided to help the designer understand the impact of the image frequency on the performance of the receiver Since SPECTRASYS knows the Channel Frequency of the specified path it also has the ability to figure out what the image frequency is up to the 1st mixer The Mixer Image Frequency measurement will show what that frequency is This image frequency is used to determine the area of the spectrum that will be integrated by the this measurement to calculate the image power The Channel Measurement Bandwidth located in the System Simulation Dialog Box is used as the bandwidth for the this measurement For example if we designed a 2 GHz receiver t
288. nning node of the path traveling in FORWARD path direction through the node that fall within the main channel All other intermods harmonics and noise is ignored in the forward path direction All signals intermods harmonics and noise are ignored for the reverse path direction For example if the Channel Measurement Bandwidth was specified to 03 MHz and the Channel Frequency was 220 MHz then the DCP is the integrated power from 219 985 to 177 Simulation 178 220 015 MHz This power measurement will not even be affect by another 220 MHz sional traveling in the reverse direction even if it is much larger in amplitude Values Real value in Watts Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DBM DCP desired channel power in dBm Real MAG DCP magnitude of the desired channel power in Watts Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DBM DCP DBM DCP DBM DCP MAG DCP MAG DCP MAG DCP Not available on Smith Chart This measurement is the desired channel power of the main channel during the IM3 analysis pass Note The Calculate IIP3 TOD checkbox must be checked and properly configured in order to make this measurement See the Calculate IIP3 TOD section for information on how to configure these tests See the Desired Channel Power measurement to det
289. nonananns 145 DEBRAULT MOD Metal een ee 135 Delete This Simulation Data oooooonnnccinncccin 50 Devane S a asia street lad mca 43 Diagonal a OM aitor tela 287 288 Di utaites 217 285 Dielectric Conan os 224 Diclechite lod ia 284 Doense 112 PINEN SIONS Add E 200 217 Dimensions TA Dsn ueia 221 Direcional Enter orea 84 Ri AAA S 243 Stress 287 Distretizes Met dios i DISCO RHO ei 52 Dist UT Mrs 1 278 Dl N 117 DEINE dadas 241 O A outs a aati aguante neue ts 110 E A AA A tet aideansena cw destands 1 Ede Metro dio 234 Effective noise input temperature 141 A wea caneeene 229 PASCO AVC oguan eana e 279 281 D T os 141 Plectonap ne UGent n a a a 1 Electromagnetic simulation 1 43 217 A R 125 134 EMport OPUNE AT 241 A A ieee 221 225 241 ENPOWE Rss 1 EMPOWER WiC W Ct ion rat 219 EMPOWER Vi Website 210 EMPOWER Viewing Results eee 208 EMV Att cast E a inset ZO SON Ene Tico tanda 287 A pac E T T E sees aalaceey 110 Equally Check antano n pda 106 dato Wizarde aria matncntcate 115 Equations 1 10 106 107 110 112 116 125 127 143 145 146 EGUN AlCHCG Veirian AA 106 A A N 110 EXCUSIVO Dr oia 106 PE RGIS Ranas 116 ED he ee ee eRe E eR A E 107 PB EE E EE EE EET 110 Esponenti anom sera 106 Exporting Data Blesa 122 EXPO ra ar aaa 122 o aa AN 107 EXCASONS sat AAA AOA 300 Extetnal Ports aio 241 259 299 Exa Deriler TAAA 302 Porapora E nen Ee TOT a 112 F Fase NEWCOM a 43 52 53 S S E
290. ns are chosen so that metal lies exactly on as large a erid size as possible The grid width and height settings for this filter were chosen as 12 5 since the filter dimensions 425x275 are exactly divisible by this value EMPOWER Operation General Layers The general layer settings for this example ate shown below LAYOUT Properties El General Associations General Layer EMPOWER Layers Fonts Silk OIF Metal OIA Substrate OIM Metal ele Silk wl Pe Mask V Y None None x None xI x 4 0 a a a OF OF Oh 0 0o 0 q g ag a None oO sl Load From Layer Fil Save to Layer File Insert Layer Delete Layer xI Only three layers had to be defined for this filter e Top Metal e Substrate e Bottom Metal These are the only layers that are needed to simulate the microstrip filter For a general layout more layers are often included for purposes only For example defining a silk screen or mask layer would not affect simulation since none of the filter metal is placed on those layers Note Since the bottom of the box will be used as a ground plane the bottom metal layer defined above may not necessary be necessary However since it is often necessary for manufacturing reasons it is normally defined here EMPOWER Layers T
291. nspection of their effects The complete file from this example is LayoutOnly WSP This example demonstrates the following topics e Creating a layout without a schematic e Choosing grid spacings e Choosing the box size A microstrip stub notch filter with a transmission zero at 9 5 GHz is to be simulated The filter has the following specifications e 15 mil RT Duroid substrate er 2 2 tan d 0 0009 e Copper metalization e 50 W terminations e The stub line should be 70 W and 90 at 9 5 GHz The series lines and the stub dimensions were calculated using T LINE and were rounded to the nearest 5 mil increment The final line dimensions are shown below Input Line Output Line le 200 mils 200 mils Open Stub 25 mils gt 25 mils Note Before beginning this example you should be sure your Workspace Window is visible Select Workspace Window from the View menu if necessaty To begin select New from the GENESYS File menu Since we do not need a schematic for this circuit we will delete the schematic In the workspace window Right click on 199 Simulation 200 Sch1 Schematic and Select Delete This Design Next we will create a layout Right click on Designs in the workspace window and select Add Layout from the LAYOUT menu Enter Stub for the layout name The Create New Layout dialog appears The tabs and prompts on this dialog are described in detail in the Basics section
292. nt Feature Activation The spectral identification feature is activated from the Composite Spectrum page of the System Simulation dialog box The check boxes involved are Totals 1 e the sum of all sionals Show Signals 1 e sources Show Intermods and Harmonics and Show Individual Components For the spectral origins to show on markers or flyover help the Show Individual Components box must be checked 91 Simulation 92 system s simulation Parameters ae X Enable e Analyzer M Mode oe A E ak E Resolution Beane ma Be RE ene ce Be oF Moo EXAMPLE Consider the Getting Stated 8 eames In the schematic there are two amplifiers Each can create second harmonics of the input signal If the output power of the second amplifier is plotted it is easy to identify source and amplitude of each of these harmonics This is true even though they are of the same frequency Consider the first source S1 at 100 MHz at the input node 1 in the schematic below EN Getting Started 8 COUPLER _1 ed CPL 10dB ATTN 3 DIR 30 dB L 4 dB JREAMPLT ro RAM G 20 dB G 10 4B ra EN E OP1DB 11 dBm 2 2 coc 9 gt OP1DB 20dBm OPSAT 13 dBm gt gt gt gt gt gt OPSAT 23 dBm QIP3 20 dBm gt gt gt OIP3 30dBra For the power from RFAMP_2 at node 7 consider the second harmonic i e 2xS1 One component is generated in the first amplifier and first appears at node 4 The designat
293. ntermod levels for the stages that created them Conducted Third Order Intermod Power CIM3P is the total third order intermod power conducted from the prior stage This measurement when used in conjunction with the Generated Third Order Intermod Power GIM3P will identify the stages in the 75 Simulation 76 chain that are the weakest link and are the highest contributor to the total intermod power The stage prior to the stage where the conducted intermods ate dominant through the rest of the chain 1s the weak link in the chain See the Getting Started 8 wsp for an illustration of these measurements Tone Dissimilar Amplitude In most cases it is assumed the two tone inputs have equal amplitude Mathematically this is the most convenient or easiest way to analyze intermod distortion However this method is not always an accurate model of the real problem like after the IF filter When both input amplitudes are equal the third order IM product level changes 3 dB for every 1 dB change in amplitude However when you have dissimilar interfering tone amplitudes the adjacent tone will change by 2 dB for every 1 dB The alternate tone will change 1 dB for every 1 dB of change Channel Bandwidth and Intermods The bandwidth of third order products is greater than the individual bandwidth of the soutces that created them For example if two 1 Hz tones were used to create intermods the resulting bandwidth would be 3 Hz The
294. nts that use noise 1 e Cascaded Noise Figure Every component in the schematic will create noise A complex noise correlation matrix is used to determine the noise power for each element at every node System Temperature This is the global ambient temperature of the entire schematic under simulation This is the temperature needed to determine the thermal noise power level For convenience SPECTRASYS will automatically calculate the resulting thermal noise power and display it just below the edit field Thermal Noise Automatically calculated info display that shows the thermal noise power given the specified temperature Noise Points for Entire Bandwidth This is the number of points used to represent the entire band of noise Noise will automatically be created beginning at the frequency specified by Ignore Frequency Below and ending at the frequency specified by Ignore Frequency Above These noise points will be uniformly distributed across this bandwidth Add Extra Points This is the number of extra noise points that will be inserted across the In Bandwidth parameter These additional noise points will be uniformly distributed across this bandwidth The center frequency of these noise points is the signal frequency These noise points will be added to every desired spectrum created in SPECTRASYS However unused noise points will be removed to improve the simulation time See Broadband Noise for additional information
295. o the noise power density dBm Hz multiplied by the integration bandwidth For channelized measurements the Channel Measurement Bandwidth is used As a result the total noise power will increase proportionally with the bandwidth Number of Noise Points There are several parameters used by SPECTRASYS to determine the number of points needed to represent the noise All noise measurements are integrated measurements whose accuracy is totally dependent on representing the noise with enough points So how does one determine how many noise points are needed Ata first glance the easy solution to this problem is to allow the user to specify the total number noise points and then make the assumption that all noise points are uniformly distributed This solution doesn t work very well for high frequency simulations that may have narrow bandwidths at a particular frequency like an intermediate frequency IF Obviously in order to represent the noise correctly in the narrow bandwidth enough noise points need to be added to eliminate integration errors On the other hand adding too many noise points will slow down the simulation 81 Simulation The solution to the noise point problem is to insert noise points using three techniques 1 Specify the total number of points to be uniformly distributed across the entire noise bandwidth 2 SPECTRASYS automatically knows which frequencies in the noise spectrum need more points It will automatically
296. odels are used to determine the impedance of each element along the propagating path of the signals Once the impedance and gain are known the correct node voltage for a given spectral component can be determined for every node for all elements Using this technique VSWR interactions are automatically accounted for For the system non linear devices such as the RF amplifier and mixer RFAMP MIXERP and MIXERA a Y matrix model is also used to determine the impedance and gain However the non linear parameters of the models such as P1dB PSAT IP3 and IP2 are used to determine the non linear behavior of the model such as harmonic intermod generation mixing and gain compression Adjacent Channel This is a channel that has the same bandwidth as the main channel but center frequency moved up or down by the channel bandwidth ACP Adjacent Channel Power Channel The combination of the channel frequency and channel measurement bandwidth For example the channel 99 5 to 100 5 MHz would be specified as a channel frequency of 100 MHz with a channel bandwidth of 1 MHz Coherent Signal Two signals which are at a constant phase offset are coherent In SPECTRASYS coherent signals must come from the same soutce Desired Spectrum This is the spectrum that originated along the specified path and flowing in the same direction as the path IF Intermediate Frequency IIP3 Input Referenced Third Order Intercept Image Channel
297. of convergence steps the simulator will take before adjusting the signal levels in the circuit Special Options Enter any of the following parameters for advanced simulator control Multiple parameters can be added on the line separated by spaces Gmin Changes the value of conductances added to each nonlinear node in the circuit The simulator by default attaches a 1 pico siemens conductance 1 teraohm resistor to each node in the circuit to assist with convergence For example to change the value to 1 micro siemens enter gmin 1e 6 HB_Oversampl Sets a factor for additional time points to be calculated during nonlinear device simulation which can improve convergence but will take additional time The factor should be set greater than 1 Typical values are 2 4 HB_NonBinaryFFT Allows the use of an FFT which is not a power of 2 For multitone problems this can greatly reduce the size of the FFT required For example a 5 tone circuit with 4 harmonics per frequency normally requires 1 024 768 points but only requires 100 000 points 1f this option is checked This speedup often makes convergence take longer for smaller circuits so it is not set by default HB_dfRelRec The amount of improvement in the error function needed before a new Jacobian is calculated Default value is 0 001 HB_dxRel The relative step size used in calculating numerical derivatives Default value is 0 001 HB_dxAbs The absolute step sized used in calcu
298. ollowing items are available in Simulations Data e Parameter Sweep e Link To Data File e TESTLINK Covered in the User s Guide Several of these capabilities work together EM co simulates with either the nonlinear or linear circuit simulator combining the accuracy of EM analysis with the generality and speed of circuit simulation Parameters sweeps can be used with DC linear nonlinear and system simulation as well as with other sweeps Frequency resistance substrate height and DC supply level are just a few of the parameters that are typically swept All of these simulations can be added to a workspace by right clicking the Simulations Data node on the Workspace Window Often we at Eagleware are asked which simulation method should be used in a particular circuit Linear SUPERSTAR Nonlinear HARBEC SPICE by exporting Electromagnetic EMPOWER SPECTRASYS For most circuits you will use a combination of the different simulations We have developed several guidelines that should simplify the decision for most applications First each method has benefits and drawbacks Linear SPICE Electromagnetic HARBEC Steady State Benefits Extremely fast Time domain Extremely accurate eee Simulation Drawbacks Schematic or netlist entry Real time tuning of circuits Uses manufacturer provided measured data Requires very little memory Easily use equations and user functions No time domain No biasing inf
299. omposite Spectrum Options Ignore Spectrum or User Defined Offset Channel Level Below 200 d m Frequency Below fo MHz F Frequency Above fi 5000 MHz Frequency Above and Below are optional The default Frequency Below is 0 and the Frequency Above defaults to 5 Max Source Freq Offset From Channel 1100 MHz Measurement Bandwidth f MHz This info is only used by the OCF and OCP Offset Channel Frequency and Power Measurements Range Warning for Miter Multiplier etc Tolerance Range 2 dB Maximum Number of Spectrums To Generate Mas Spectrum A Cancel App Help Factory Defaults When these parameters are used in conjunction with the Offset Channel Frequency and Offset Channel Power measurements the user is able to determine the integrated channel power for an arbitrary channel relative to the main channel Furthermore both the Freq Offset from Channel and the Measurement Bandwidth parameters can be made tunable by placing a in front the parameter to be tuned For example perhaps you would like to determine the power of some signal at 100 MHz offset from the main channel The Freq Offset from Channel would be set to 100 MHz and the Measurement Bandwidth could be set to the a user defined bandwidth for example 1 MHz The OCF Offset Channel Frequency measurement could be added to a table to show the user the actual frequency
300. on Simulations Data node and select Add Harmonic Balance Simulation Accept the default name Click OK 2 Enter Design to Simulate Amplifier Order 5 and click OK 12 Walkthrough DC Linear HARBEC General Advanced Oscillator Design To Simulate AmpliFier pS Signal Sources E Hame Freg MHz Order a 900 5 Maximum Mixing Order 10 Temperature 27 0 e Maximum Analysis Frequency Calculate Automatic Recalculation AutoSave Workspace After Calculation Recalculate Mow m Calculate Nonlinear Noise 4dds Noise Tone 3 Inthe Workspace Window right click on Outputs node and select Add Rectangular Graph Name the Graph Spectrum 4 Enter the following Default Simulation Data or Equations HB1 Amplifier Measurement P1 5 Click OK Click the Calculate icon in the toolbar and the graph displays the input spectrum as shown below Note The input spectrum shows higher than expected because the input is not matched This measurement works mote intuitively on output ports 13 Simulation 14 JE GENESYS V7 5 Spectrum Workspace HB2 Pa YY Y AT E E HB1 Ampli E IB Sweep YC Sweep 2250 Freq MHz 6 Inthe Workspace Window right click on Outputs node and select Add Rectangular Graph Name the graph Waveform 7 Enter the following Default Simulation Data or Equations HB1 Amplifier Measurement line1 tim
301. on to the lengths using the multimode lines will not affect the calculated loss In general if the decomposed pieces cover the circuit completely as is the case in the spiral inductor then the losses will be accurate If the pieces do not completely cover the circuit if sections of line are left out of the EMPOWER analysis and are added with MMTIP sections then the losses will not include these sections This is true regardless of the reference plane shifts used since these shifts do not affect the loss You must be very careful when setting up and numbering ports for decompositional analysis The following rules must be followed e Never connect anything other than MMTLP lines or other identical modal inputs to inputs which are modally related Connecting lumped elements to modal inputs is incorrect and will give bad results e Ports which will be modally related must have sequential numbers They must also all have the same reference shift e Ports for mode space inputs must be marked type Normal not No deembed ot Internal Correspondingly their numbers must be lower than any No deembed or Internal ports e The order of ports used must correspond between the pieces and the MMTLP lines used The lowest port number in a modally related set of inputs should connect to Mode 1 in the MMTLP line and the highest port number in the set should connect to Mode N on the MMTLP line Also port ordering should be e
302. onatacega se evecsasemucameeveunae ener 86 Composite peca id 88 destityinoSpectral Otis id 90 SOME 93 OR 93 O 96 O NA 96 Ste oia ton Sidi ie 98 Table Of Contents Patame Het OWI yaaa 101 Parameter Ow ee ropero 101 SEAS TS TES ROA ROO pu O E 103 Ne wld Or Vanable Valle Suso diri 106 A O TO 106 Sample Express it id 107 Puita Pucon toi 107 Constant mania 110 deta 110 ray Vectors and Matrices ri ad 110 Post Procesan Oi 142 EUA nO IZA iia 115 Gap AI AIO UN pta 115 Equations ithe Equations Sect On inners actos sist ad uicahaaceceer laren van anaansioss 115 THO RICA Peritos li A S 116 User PUNO cas oleo 116 Calino Your POR TRAN C C FF DLE et da 117 Egma tons Iii ta ies 117 linear ys Nonlinear Device Modest anat 119 Kocit Da yes 119 Usuri Data let GENES Slide 119 TODA lt Sateen 120 Lokte Data ile SOU 120 Reovded Device Di e O 120 Creatine Newlantar Dat lesa a 120 Ele Record ESP dad 122 PS pO rite Data PIES AA AAA daa 122 Noise Data Data Blest ias tds 122 Nonlinear Device libri its 123 ONCE ti a 125 Ureatino A Mod kanien io 125 User Model Example A Seli Resonant Capacitor cuasi 127 Model Properties ii di aliada 133 Usina Model lrs CHE MA X iron eres ate 134 Saole Dart MOE AS AAA AAA AAA 134 Table Of Contents Text Model Definitions adas 135 ONE E a A EER TAO 157 SPRICE ile Compatibilidad 138 LARIOS PCE lara tit 139 AR 141 linear Measurement salda 141 Nonlitiear Measurement E A O 143 Operatoria 143 Sample Measures
303. or is 2xS1 4 6 8 7 The amplitude is about 95 dBm as shown either in the flyover box or in the marker text Notice that the flyover text has the long form of the identifier whereas the marker text is the short form The component generated in the second amplifier RFAMP_2 has the designator 2xS1 7 since it first appears at node 7 The amplitude is 90 dBm Sources SPECTRASYS System BE Amp 22 Out Workspace Getting Started 48 2nd Amplifier Output DEMIP7 Frequency MHz DBh P7 TROUBLESHOOTING If the identifiers do not appear on the graphs check the Composite Spectrum page of the System Simulation dialog box Make sure that the Identify Individual Components Above box is checked If intermods or harmonics are desired put a check mark in the Show Intermods and Harmonics box Sources Sources ate a very powerful feature of the SPECTRASYS There are 4 basic types of sources They ate e Continuous Wave CW e Modulated e Noise e User Defined Signal sources CW Modulated and User Defined are defined by a center frequency bandwidth power level phase shift and number of points Every one of these parameters can be tuned by placing a question mark in front of the parameter All sources are assumed to have a uniform spectral density Every source can be easily enabled or disabled by checking or unchecking the Enable checkbox in the source table on the General page of the System
304. orkspace can be overridden by using the following format workspace simulation design operator measurement where workspace is the short name of the workspace as given in the Workspace Window This allows direct comparison of results from different workspaces Some examples of overrides ate Meas Linear1 Filter DB S21 Meaning Show the dB magnitude of S21 from the Linear1 simulation of the 145 Simulation 146 Filter design EM1 Layout1 S11 Show the dB magnitude of S11 from the EMPOWER analysis of Layoutl Filter QL S21 Shows the loaded Q of the Filter design using the current simulation Note that the simulation was not overriden only the network DB Linear1 FILTER S21 ILLEGAL The operator must go around the measurement not the wrong override Equations X Shows the global equation variable X which must contain post processed results TUNEBP Linear1 Filter DB S21 Overrides the workspace Shows the dB magnitude of S21 from the Linearl simulation of the Filter design from workspace TUNEBP Data1 A Show all input admittances from a Link to data file Note that in this case the design name is not required Anywhere that a measurement is used post processed equation variables can be used The format is EQUATIONS varrableNarme where variableName is a variable from the Global equations for that workspace For example EQUATIONS X uses variable X from the global equations A workspace override can also
305. ormation Everything is linear Requires knowledge of circuit coupling factors parasitics etc Schematic or netlist entry Starting waveforms e g oscillator startup DC biasing information Lots of vendor supplied models Non linear modeling of Crossover distortion etc Very slow Very hard to model frequency domain behavior e g unloaded Q No distributed models e g microstrip waveguide etc Requires knowledge of circuit coupling factors parasitics etc Does not require an intimate knowledge of the circuit simulator figures out coupling etc Can predict radiation current distribution Automatic deembedding Predicts box mode effects e g What happens if the circuit is placed in a box Can use arbitrary shapes does not require an existing model for them Extremely slow Requires lots of memory Discretizes metal patterns to fit grid Can be difficult to set up a circuit for simulation Study mixing compression and intermodulation DC biasing information Lots of vendor supplied models Use frequency dependent equations and post processing Use measured data in simulation Much slower than linear Takes a lot of memory and time Requires nonlinear models Cannot study transient behavior for example oscillator startup In determining which simulation type to use several points should be considered
306. output spectrum of the mixer Obviously no mixed output spectrum will be created unless an LO signal is present on the LO pin of the mixer If the bandwidth of the LO signal is greater that 25 Hz the mixer will kick into a convolution mode and all highest power LO spectrum will be convolved will all input sionals to create mixed output spectrum The convolution process is much mote time consuming and the simulation time will increase Currently the LO power does not affect the conversion loss or gain of the mixer Instead the power of the LO is determined and compared with the Warning Range specified on 79 Simulation 80 the Options Tab of the System Simulation Dialog Box The user will then be warned if the mixer is being starved or is over driven by the LO Signal Spectrum Arriving at the RF Port All spectrums arriving at the RF input port will be propagated to the IF and LO ports through their respective isolations Next the actual conversion gain loss of the mixer is determined by examining the total power appearing at this port This total power is used to determine whether the internal amplifier connected to the RF port is being compressed or saturated For more information on the amplifier model see the Amplifier section Any gain compression will be applied to that conversion gain loss specified in the model along with any VSWR effects Before any sum and difference frequencies are created the entire non linear spectru
307. over type usually has no effect on analysis time so there is no reason not to set this to the proper type With an open cover there will be radiation and this can have a huge impact on circuit performance You can choose the correct cover types in the Layers Tab when starting an EMPOWER run See the EMPOWER Basics and Box Modes sections for more information on covers See the Edge Coupled Filter example for an example of the impact that removing a cover has on circuit performance If you do not need information about circuit loss you can check the box labeled Don t use physical loss Faster when starting an EMPOWER run Turning off losses will generally make a problem require 1 2 the memory and 1 4 the time as a lossy problem We recommend that you define all layers with their proper characteristics including losses You can then quickly change between lossy and lossless modes as described above A common technique is to analyze a circuit first without losses then turn on losses and run an analysis with a few points in it This allows you to determine the amount of loss and confirm that it has no other major effect on performance while not having to wait the additional time while doing most of your analyses There is an additional caveat regarding loss described in the section on Slot type structure See the Narrowband Interdgital example for an example of the effect of loss on an interdigital filter 236 EMPOWER Tips Looki
308. parent location of the viewer window relative to the current image Pan Left Ctrl Left Moves the viewer location to the left relative to the current image This moves the image to the right in the viewer window EMPOWER Viewer and Antenna Patterns Pan Right Ctrl Right Moves the viewer location to the right relative to the current image This moves the image to the left in the viewer window Pan Up Ctrl Up Moves the viewer location up relative to the current image This moves the image down in the viewer window Pan Down Ctrl Down Moves the viewer location down relative to the current image This moves the image up in the viewer window Pan Zoom In Ctrl PgUp Moves the viewer location closer to the current image This increases the size of the image in the viewer window Pan Zoom Out Ctrl PgDn Moves the viewer location away from the current image This decreases the size of the image in the viewer window Toggle The objects in this sub menu toggle the available options listed below Toggle Absolute Value Display When selected the viewer displays absolute values only If not selected an actual value with information about flowing direction 1s displayed The difference is that absolute value is always positive whereas the actual current values can be positive for forward directed currents and negative for backward directed currents Negative amplitudes are drawn below the x y plan
309. plete the current calculation mode Each frq The estimated calculation time per frequency in the current mode Estim RAM The estimated total memoty required for the current simulation The fourth line displays the simulation time of the current frequency and symmetry plus the symmetry stage The fifth line displays the calculation stage The lines below the fifth line describe the calculated data for each frequency During line analysis the impedance Z and propagation constant G are displayed for each frequency In the discontinuity calculation mode the first row of the s matrix is displayed at each frequency Starting with GENESYS Version 7 0 multiple workspaces can be loaded simultaneous and all EMPOWER simulations can be updated sequentially This new capability makes the techniques given in this section much less important for most users Simply open as many Workspace files as you need Select Options from the Tools menu and check Allow Multiple Open Workspaces Right click on any of the EMPOWER simulations and press Recalculate Now You will then be asked if you want to recalculate all simulations select Yes Note You should probably check Automatically save workspace after calc if you are running long or overnight batches so that if there is a power outage you will not lose your results 231 EMPOWER Tips Often electromagnetic simulation involves tradeoffs and compromises to keep simulation tim
310. plications by clicking on the Model button Click OK Note To place a specific manufacturer s transistor model you first place the appropriate picture then change the model for the part to a device model 3 Click on the Source icon in the toolbar select Current Probe Ammeter and place it on the collector of the transistor Enter Designator IC Click OK Use Edit Mirror F6 if necessary to show the current flow into the collector or the transistor and or Edit Rotate F3 to rotate the ammeter 4 Select a DC voltage source from the toolbar place it on the other side of the ammeter and enter DC Voltage 1 Designator VC Click OK 5 Click on the Source icon in the toolbar select Source DC Current Enter Current P5e 6 Designator IB Click OK Press F6 if necessary to show the current flow into the base of the transistor 6 Press G on the keyboard or press the ground button on the toolbar and place a ground on the other end of the current source Click OK 7 Press the Space Bat reselect previously placed parts and place another ground on the emitter of the transistor The schematic should look like the following without the DC bias voltages and currents shown Simulation BDC Curves MW orkspace HB IDC 500e 6 A IE IDC 5e 6 A 8 Save your file now and remember to save frequently 9 Inthe Workspace window right click on the Simulations Data node and select Add DC Analysis Ac
311. pr Notice that gamma goes to zero if the reference admittance is optimal Values Real value versus frequency Simulations Linear Default Format Table Linear Graph Linear Smith Chart GOPT Commonly Used Operators none Examples Measurement Result in graph Smith chart Result on table optimization or yield GOPT gamma coefficient gamma coefficient The Optimal Admittance for Noise is a complex function of frequency and is available for 2 port networks only The optimal admittance is the value of the input admittance which minimized the noise fioure of the network The optimal admittance is defined in terms of the source admittance Ys and the noise resistance Rn and the noise figures NF NFMIN as NF NFMIN Rn Re Ys Ys Yorr The optimal impedance is the inverse of the optimal admittance i e Zopr 1 Yorr 159 Simulation 160 Values Complex value versus frequency Simulations Linear Default Format Table RECT Graph RE Smith Chart GOPT Commonly Used Operators Operator Description Result Type RECT YOPT real imaginary parts Real RE YOPT real part Real MAGANG YOPT Linear magnitude and angle in range of 180 to 180 Real Other Operators MAGI ANG ANG360 IM MAGANG360 Examples Measurement Result in graph Smith chart Result on table optimization or yield YOPT real part of optimal admittance real imaginary parts of admittance The Effective Noise Input Temperature
312. r D Nonlinear Diode E F G H Controlled Sources I Current Source J Nonlinear JFET Only JFET JFET2 is not yet available K Mutual Inductance Only works in DC and HARBEC not linear simulation L Inductor M Nonlinear MOSFET As of GENESYS Version 7 5 release only level 1 MOS1 is available Q Nonlinear BJT R Resistor V Voltage Source X Subcircuit Z Nonlinear MESFET Transistors Model types NMF and PMF are available You must add a level parameter to the model to indicate which type of MESFET model will be used 1 Curtice Quadratic 2 Statz 3 TOM 4 Original SPICE 3F5 MESFET 5 TOM2 6 Curtice Cubic For parameter details see the corresponding element in the Element Catalog Link to Spice File For example a SPICE model for an XYZ143 device using a TOM N Channel model in it might look like model XYZ143 NMF LEVEL 3 VTO 2 5 CGS 1e 12 If there are any compatibility errors in the SPICE file the errors will appear in the GENESYS error window when a DC or HARBEC simulation is tun which uses the link To open Create a new Link to Spice Model Link to Spice File Filename fu otordlaRFBJTABFR33 LIB E Model Subckt Name BFRs3 Subcircuit with 3 Modes 100 200 300 Cancel Spice Part x surcit S Number of Nodes E I Reverse Nodes 1 amp 2 Normally checked for transistors and amplifiers Filename The name of the library file containing the spice model If you will be sharing
313. r is lossy and is described by an impedance or file This type is commonly used for resistive films and superconductors If the entry in this box is a number it specifies the impedance of the material in ohms per square If the entry in this box is a filename it specifies the name of a one port data file which contains impedance data versus frequency This data file will be interpolated extrapolated as necessary See the Device Data section for a description of one port data files e Substrates Choosing a substrate causes the layer to get the rho thickness and roughness parameters from that substrate definition We recommend using this setting whenever possible so that parameters do not need to be duplicated between substrates and layouts Caution Unless thick metal is selected thickness is only used for calculation of losses It is not otherwise used and all strips are calculated as if they are infinitely thin Metal layers have three additional settings available Slot Type Check this box to simulate the non lossless metal areas as opposed to the metal areas in EMPOWER Use this for ground planes and other layers which are primarily metal Do not use this for lossy layers See your EMPOWER manual for details Current Direction Specifies which direction the current flows in this layer The default is along X and Y X Only and Y Only can be used to save times on long stretches of uniform lines Z Up Z Down XYZ Up and X
314. ract a generalized scattering matrix of the problem from the immitance matrix the method of simultaneous diagonalizations is used After this introduction we ate ready to formulate the reasons for using MoL as a basis for an electromagnetic simulator The 3D problem is discretized only in two directions and reduced to a 2D one that corresponds naturally to the planar MIC structures In contrast with the method of moments the MoL gives a self regularized solution with only one variable grid cell size defining all parameters of the numerical model That eventually leads to monotonic convergence of calculated data and predictable errors of calculations The high grade of internal symmetries of the MoL based algorithms makes it possible to substantially reduce the numerical complexity of the main matrix computation stage The main restriction of using a regular grid related with its potentially excessive number of variables has been overcome by introducing thinning out and re expansion procedures Basically the discrete analogue of a problem is processed in a way similar to the method of moments but in discrete space like the finite difference approach which facilitates different aspects of the solution and programming Thus the main advantages of the MoL are reliable solution with the predictable calculation error relatively straightforward algorithms that facilitate development of general purpose programs and a lot of possibilities to speed up calc
315. rected currents are not taken into account therefore it is not recommended that you include vias in the layout Setting Up the EMPOWER Box To get good results for the far field radiation patterns the following rules must be observed e The structure should be centered in the box e The walls of the box should be far away from the structure e Only one layer of metal must be used e Exactly one substrate or an Air Below layer must be under the metal layer not both There are 3 different antenna types for which far field radiation patterns can be generated e Antenna in free space EMPOWER Viewer and Antenna Patterns e Antenna above a ground plane e Microstrip antenna above a substrate and ground plane To simulate an antenna in free space no substrate should be used and the only layer below the metal layer should be Air Below The height of the Air Below layer in this case is irrelevant Both the Top Cover and Bottom Cover should be set to Electrical type with surface impedance set to 377 ohms 377 ohms is the intrinsic impedance of free space To simulate an antenna above a ground plane with no substrate the Air Below layer should be set to the height the antenna is to be above the ground plane The Bottom Cover should be set to Lossless type and the Top Cover should be set to Electrical type with surface impedance set to 377 ohms To simulate a microstrip antenna the Air Below layer should not be used The substrate
316. resholds Specifies the maximum number of lines in a row which can be thinned out Max box size to media wavelength ratios If the box is too large you will have box resonances If this line ends with an exclamation mark it may be too large See the Box Modes section for more details PACKAGE STRUCTURE This section is only present when the Extra Details in Listing File option is used It gives a summary of the substrate and metal layers used as well as cell sizes MEMORY SECTIONS Several memory sections throughout the listing file give memory requirements for different parts of the simulation MAP OF TERMINALS This section shows the grid representation of the problem SDTC SECTION EMPOWER File Descriptions Symmetry detection sections specify whether the structure is symmetrical The symmetry processing additionally shows where any differences occurred and can be very useful in finding out where the structure is not symmetrical The coordinates specified refer to the terminal map shown above LINE ANALYSIS MODE RESULTS This area of the listing contains sections identical to those described above which pertain to the line analysis Below these sections you will find a table of line parameters for each frequency The entries are Nm port number Type impedance type real re or imaginary im Normal lines should have a real impedance Zo ohm Line impedance Gw rad m propagation constant Gw Go propa
317. rs which are aligned horizontally or vertically e In all other cases an internal port is used for each terminal of the element This port is placed at the center of the pad footprint and EMPOWER writes data for each port created whether internal or external e The 1 and 2 ports pictured in the figure above are examples of external ports Ports are described in the External Ports and the Internal Ports sections e This is a powerful technique since real time tuning can be employed in GENESYS once the EMPOWER data for has been calculated Double click EM1 in the Workspace Window This displays the EMPOWER Options dialog shown below EMPOWER Options x Layout to simulate META dd OF Port impedance E Generalized Cancel 7 Automatic Recalculation Recalculate Mow itt Electromagnetic simulation frequencies Start freg MHz f 400 AN T Automatically save workspace after calc Stop freg MHz 2600 Viewer data Generate viewer data slower Number of points E Max critical freq 2600 Port number to excite 11 il Mode number to excite 11 T Turn off physical losses faster T Only check errors topology and memory do not simulate Advanced Options Co simulation sweep Setup Layout Port Modes Use EM simulation frequencies Start freq MHz fi400 Thinning out subgrid Stop freq MHz 2600 A F Thi etch E D M Thin out electrical lossy surfaces T Solid thinni
318. rt a b 72 6 DBM P2 Total from FF ASMP _1 c r2 5111456582 2 20 MHz a 173 9134 Total from Port2 bj 150 5059 Total from RFAMP_1 c1 179 2x51 2 3 90 MHz a 1473 9134 Total from Port2 b 131 3914 Total from RF AMP _1 cj 131 4451 ar 5682 DBM P2 Frequency MHZ One of the most useful features of composite spectrum is is the ability to identify the origin and path of each spectral component See Identifying Spectral Origin and System Simulation Parameters Composite Spectrum for more information Identifying Spectral Origin Since each spectral component is tracked separately and SPECTRASYS knows the direction of travel of all signals the user can find the origin and path of each spectral component by placing a marker on the graph or simply flying the mouse over the spectral component of interest When a graph marker is added to a plot the marker will attach itself to the closest data point Also the mouse flyover text appears when the mouse ts over the marker symbols trace segment endpoints or the marker text on the right side of the graph These marker symbols can be enabled or disabled The default marker symbols look like large round dots If the user is having a difficult time trying to get the mouse flyover text to popup it is because the mouse cursor is not near a marker symbol The best solution to this problem is to enable the marker symbols so the user can see the marker locations and place
319. rvals are as specified in the Linear Simulation dialog box For a n noise sources the elements are of the form Nj fori j equal 1 2 Note See References 5 6 for a complete discussion of noise correlation matrix properties Values Complex matrix versus frequency Simulations Linear Default Format Table RECT Graph RE Smith Chart none Commonly Used Operatots Operator Description Result Type RECTIN11 real imaginary parts Real RE N22 real part Real MAGANGJ N21 Linear magnitude and angle in range of 180 to 180 Real Other Operators MAGI ANGI ANG360 IM MAGANG360 Examples Measurement Result in graph Smith chart Result on table optimization or yield N22 RE N22 real part of N22 RECTIN Shows real imaginaty parts of all N Parameters MAGIN21 Linear Magnitude of H21 Linear Magnitude of N21 N Shows real imaginaty parts of all N Parameters Not available on Smith Chart Measurements Linear The Simultaneous Match Gamma is a complex function of frequency and is available for 2 port networks only Computes the reflection coefficient that must be seen by the input port 7 to achieve a simultaneous conjugate match at both the input and output Values Complex value versus frequency Simulations Linear Default Format Table RECT Graph RE Smith Chart GMz Commonly Used Operators Operator Description Result Type RECT GM1 real imaginary parts Real RE GM1 real part Real MAGANG GM2
320. s e Electrical Desc The cover is lossy and is described by an impedance or file See the description below under metal for more information e Semi Infinite Waveguide There is no cover and the circuit is simulated as if the box walls and uppermost substrate air layer extend up or down forever an infinite tube e Magnetic Wall The cover is an ideal magnetic wall This setting is only used in advanced applications e SCHEMAX substrates Choosing a SCHEMAX substrate causes the cover to get the rho thickness and roughness parameters from that substrate definition We recommend using this setting whenever possible so that parameters do not need to be duplicated in SCHEMAX and LAYOUT Air Above and Air Below The presence of air at the top of the box as in microstrip or the bottom of the box as in suspended microstrip is so common that special entries have been provided for these cases Checking the box to turn these layers on 1s the equivalent of adding a substrate layer with Er 1 Ur 1 and Height in units specified in the Dimensions tab as specified 219 Simulation 220 Caution When setting up a new circuit be sure to check the height of the air above as it is often the only parameter on this tab which must be changed and is therefore easily forgotten Metal Layers In LAYOUT multiple METAL layers e g copper and resistive film are automatically converted to one EMPOWER signal layer if no media layer is in be
321. s columns Returns a 2 dimensional array of size rows x columns See Arrays later in the equations reference MIN expression Finds the minimum value of a post processed expression MAX expression Finds the maximum value of a post processed expression PLOTPOINTS expression Plots 2D input data points on a Smith Chart without connecting the dots Useful for seeing what data points have defined measurement values in a load pull file REAL expression returns the real part of a complex number Alternate form RE expression RND returns a pseudo random number between zero and one SIN expression sine of the argument SINH expression hyperbolic sine SQR expression square root TAN expression tangent Range Argument must not be 90 3 90 etc TANH expression hyperbolic tangent Range Same as TAN expression VALUEAT expression real imag smoothParm Returns the value of the thin plate spline generated from 2D data in expression at a given coordinate real imag The smoothParm parameter is optional see function CONTOUR VECTOR expression returns a vector array of size expression See Arrays later in the equations reference 109 Simulation 110 Name Value PI p 3 14159265 _EPSO 8 854e 12 _ETAO 376 7343 _MUO 1 256637e 6 _VAIR c 2 997925 8 _LN2 In 2 0 6931471805599 _EXP1 e 2 718281828459 _RTOD Radians to degrees multiplier 180 pi _DTOR Degrees to radians multiplier pi
322. s IF SPECTRASYS Intermods and Harmonics 73 SPECTRASYS Level Dia crams ssicnidaness 86 SPECTRASYS Measurement Bandwidth 68 SPECTRASY S Middle 26 SPECTRASYS Offset Channel ecce 70 SPECLTRASYS OPUS psi 70 SPEC TRASY 3 OOULCES irrita 93 SPECTRASYS Spectral Origin 90 SPECTRASYS Tone Channel Frequency 175 tales 85 A tsa eoedi ie adda twnies 1 51 139 SPICE File Compatibility nuisances 138 Spital INGUCtOL arias 236 249 250 257 aio 107 Sare E B O AS 41 SS 304 A eaa a O 141 145 Stabi Ele it S E 158 Stability Factoria idas 158 SADNO Measure A ee AA eee 158 O A re esa corer 107 110 A A ame aes 217 SUSIE CTOTICS aa tdi 299 A re SPER OTE vee errr rere ern rye 217 a acco E ene seat 217 224 Substrate thie KICS S cidad ecoaade 236 o A deo A 106 SUPercON UC aii adas 217 A tenes O 1 Suttace ROUCKHESS cantaba 217 Suspended MIC 217 SWE e 07 UE OO E E 31 101 SVANEN esa n E ree 234 287 Symmetry PLOCESSING atcrsaionton tod ti triir 302 System Models a e NSA 55 System Simulation Parameters 22 57 58 61 65 T A A E EEO 107 AE at D A A PAE A AEE 217 O A E E NO E TEA 107 A E E O O 175 Temperat ann n E RE 141 TEE n e A 120 Tena O do 120 Terminado nS dE 35 141 TO a a 300 Text Model Definitions an 135 Tack Metalicas 239 IE ESSE rado 217 Thin andas aci n 239 201 Thrd order interceptado 52 O O A cauanpscnesodonies 119 Toggle Background Colot ieee 219 LOAN CES bn 41 43 Tone Channel Pregn eurenean 193 LO CO
323. s are as specified in the Linear Simulation dialog box This measurement is the same as the linear measurement of the same name A port number 7 is used to identify the pott ZPORT is the reference impedance for port z Values Complex value versus frequency Simulations Linear Default Format Table RECT Graph RE Smith Chart None Commonly Used Operators Operator Description Result Type RECT ZPORT1 real imaginary parts Real RE ZPOR T2 real part Real MAGANG ZPORT3 Linear magnitude and angle in range of 180 to 180 Real Other Operators MAGI ANGI ANG360 IM MAGANG360 Examples Measurement Result in graph Smith chart Result on table optimization or yield Measurements Nonlinear ZPORT2 RE ZPOR T2 RECT ZPORT2 RECTI ZPORT Shows real imaginaty parts for all ports MAG ZPORT1 Linear Magnitude of ZPORT2 Linear Magnitude of ZPORT1 ZPORT Shows real imaginary parts of all ports Not available on Smith Chart Large signal S parameters can be measured in a HarBEC simulation Unlike linear S parameters nonlinear large signal S parameters depend upon the signal magnitude and must take into account the harmonic content of the input and output signals since energy can be transferred to other frequencies in a nonlinear device Large signal S parameters are very useful in characterizing devices operating in the nonlinear range Note You must have a signal at the input port to use these measurements
324. s calculated versus time If f is the incident wave frequency the current distribution Ig t at time t is given by expression Ig t 18 0 expg 2 pr t t The same formula is valid for the voltage distributions Advancing time displays snapshots of the current or voltage distribution thus animating the display As we mentioned above the viewer reads the grid currents or voltages with their coordinates and prepares them for plotting The preparation stage includes a transformation of the grid variables to more general current density functions surface electric current density function for strip like problems or surface magnetic current density function for slot like problems The units for the electric current density magnitudes are Amperes per millimeter A mm The units for the magnetic current densities are Volts per millimeters V mm We choose millimeters to scale graphs to more readable values The current density functions are created only for the currents in the signal or metal layer Viaholes and z directed ports are always represented as z directed currents in Amperes To summarize viewer behavior e If Generate Viewer Data is selected the default incident wave is the first eigenwave of the first input e Define the input number and mode number in the EMPOWER properties dialog e An incident wave is a time harmonic function with unit magnitude and zero initial phase e The external ports are terminated by corresponding mode
325. s found on the System toolbar 23 Simulation S01 IL 1 dB IS0 40 dB 3 dB Resistive Pad L 2 dB RS G 15 dB R 141 9 ohm pose OP1DB 40 dBm OPSAT 43 dBm DIP3 50 dom OIP2 60 dBm 1 If you haven t been saving your work you should save your file now 2 Open the Output Spectrum graph With the input power tuned to 0 dBm and the measurement bandwidth set to 1 MHz you should see the following graphs Note that the noise has risen 20 dB 15 dB from the amplifier gain and 5 dB from the amplifier noise figure 24 Walkthrough SPECTRASYS output Spectrum Workspace 4 Tuning Parameters 1 100 MHz a 114 702 Total from Port2 b 9 008 Total from RFAMP_1 c 9 008 DB C GAIN DB CGAIN Note that on the output spectrum you can see the harmonics Try passing your mouse over the harmonic to see the level and the source 25 Simulation Note The walkthrough at this point is saved in Examples SPECTRASYS Walkthrough 5 Amplifier WSP Next we will mix our 100 MHz signal up to 2 GHz using a 1 9 GHz LO and a mixer 1 Modify the schematic to be RFAMP_1 6 15 dB MIXERP_1 MF 5 dB CL 8 dB OP108 40 dam SUM 1 ISQ_1 OPSAT 43 dBm LO 7 dom IL 1 dB OIP3 50 dam IP2 21 dBm I50 40 dB 3 dB Resistive Pad OIP2 60 dBm R2 R 8 5 ohm R3 R 141 9 ohm Note that we changed the units on the LO to GHz This is very easy to do inside the schematic element dialog box The mixer is the
326. s in circuit theory and internal ports in EMPOWER In the circuit theory schematic on the left there are two ports Each port has two terminals with the bottom terminal generally being ground In the EMPOWER illustration there are two z directed ports one at each end of the line These z directed ports are mapped onto the grid along Z much in the same way as a viahole would be mapped See the Basics section for more information on mapping to the grid As in the circuit theory schematic there are two ports and each port has two terminals The bottom terminals which are true ground in the circuit schematic are connected to the bottom wall ground plane a physical representation of ground Z directed internal ports can be used in GENESYS to connect elements just like a node in SCHEMAX or in a text file In other words components like resistors and transistors can be connected directly to these ports You simply place a z directed port in the center of the pad for the component in these cases Note SCHEMAX does this automatically as is described later in this section 259 Simulation 260 Note GENESYS will automatically add lumped elements to your simulation if components are on your layout This section is for background information and advanced applications The circuit shown below contains an EMPOWER circuit which was drawn completely in LAYOUT The schematic for this network was blank It has 4 ports ports 1 and 2 are ext
327. s specification of start and stop frequencies and space between points e List of Frequencies Allows the explicit specification of analysis frequencies These points are entered into the List of Frequencies box separated by spaces Factory Defaults Resets the sweep properties to the original known good settings Temperature The ambient temperature of the linear simulation Overview The purpose of this section is to summarize network analysis concepts and to define some of the parameters plotted by GENESYS For further details on measurements see the Measurements section of this manual Networks are considered as black boxes Because the networks are assumed to be linear and time invariant the characteristics of the networks are uniquely defined by a set of linear equations relating port voltages and currents A number of network parameter types have been developed for this purpose including H Y Z S ABCD and others These parameters may be used to compute and display network responses and to compute quantities useful for circuit design such as Gmax maximum gain and gain circles Each parameter type has advantages and disadvantages Carson 1 and Altman 2 provide additional information S Parameter Basics S parameters have earned a prominent position in RF circuit design analysis and measurement Parameters used earlier in RF design such as Y parameters require opens ot shorts on ports during measurement This is a
328. s that you are familiar with basic concepts of binary arithmetic and logical operators Whenever a logical operation such as amp or is performed the values used are first converted to 32 bit signed integers truncated The operation is performed and then the numbers are converted back to floating point format This causes logical operators to work as expected when combined with relational operators true is given a value of 1 which corresponds to all ones in binary notation false is 0 which corresponds to all zeroes So when a logical operation is performed after a relational test the value is either 1 true or O false This is the rationale for having the IF THEN GOTO Statement branch on a nonzero value Relational operators act as expected on binary numbers although there are no facilities included for conversion between binary and decimal format So the value of 5 amp 4 is 4 and the value of 128 64 is 192 The not operator changes each O in the binary representation to a 1 and changes each 1 to a 0 Here are logical operator truth tables A B 1A A amp B A B 0 0 1 0 0 0 1 1 0 1 1 0 0 0 1 1 1 0 1 1 Functions can be created in GENESYS Their format is FUNCTION same parm parm equations RETURN expression Functions take zero or more parameters as input and return exactly one value as output All variables used within a function are local that is variables cannot be shared across functions or with the main Eq
329. s which appear in the tune window marked with are available to be swept Automatic Recalculation Checking this box will cause the harmonic balance simulation to be run any time there is a change in the design If the box is not checked the simulation must be run manually either by right clicking on the simulation icon and selecting Recalculate Now or by clicking the recalculation button on the main tool bar Recalculate Now Dismisses the dialog box and starts the simulator if required If the circuit has already been simulated and has not been changed the simulator will not calculate again Factory Defaults Resets the sweep properties to the original known good settings Sweep Range e Start Value The lower bound minimum frequency of the sweep e Stop Value The upper bound maximum frequency of the sweep Type of Sweep e Linear Number of Points Allows specification of start value stop value and number of points e Log Points Decade Allows specification of start value stop value and number of points e Linear Step Size Allows specification of start value stop value and space between points e List of Values Allows the explicit specification of variable values These points are entered into the List of Points box separated by spaces Equation Reference Each line in the EQUATION window must be in one of 5 formats assignment REF comment IF THEN GOTO FUNCTION RETURN or BASE The formats are
330. s you might run into convergence issues Below are a few steps that you can use to improve convergence results Each of the parameters below is changed on the Harmonic Balance HARBEC Options dialog box 1 Increase the number of frequencies the order used in analysis If not enough frequencies are used the data is being undersampled and cannot accurately represent the solution For example modeling a square wave with three harmonics will ignore a lot of energy in the circuit often leading to convergence issues Increasing the number of frequencies analyzed will more accurately model the signals at the expense of more time 2 Try Always and Never options for calculating the Jacobian If a Jacobian is calculated the simulator will search in a different direction from the Fast Newton 52 HARBEC DC amp Harmonic Balance method Sometimes the Jacobian will be a better direction sometimes it will be worse Try both approaches 3 If the convergence issue occurs during a parameter sweep sweep more points so that that each simulation is closer to the previous one often requiring less total time Or if this is not practical or desired turn off Use Previous Solution As Starting Point This will cause the simulator to start fresh with each new parameter value 4 Increase the value of Absolute Tolerance and Relative Tolerance This should speed up the solution but will be less accurate particularly for low signal levels A
331. se Select All from the Edit menu 2 Choose Center Selected On Page from the Layout menu Before running EMPOWER the filter s ports must be designated Select the EMPort button El on the LAYOUT toolbar and click on the center left end of the series line The EM Port Properties dialog appears Set the drawing size to 25 This controls how large the ports will be drawn on the LAYOUT screen Note that the default port number is 1 Select the OK button Next select the EMPort button on the toolbar again Click on the center right end of the series line The EM Port Properties dialog appears Again type 25 into the Draw Size box Note that the default port number is 2 Select the OK button The screen should now look like 205 Simulation 206 BE Layout Workspace WorkSpace 1 Mei E3 For simulation EMPOWER will take S Parameters from these ports To run EMPOWER you must create a simulation Right click on Simulations Data in the WorkspaceWindow and choose Add Planar 3D EM Analysis from the menu Accept EM1 as the analysis name This displays the EMPOWER Options dialog This dialog is shown below For a description of the dialog options see the section on External Ports For now just set the prompts as shown below EMPOWER Operation EMPOWER Options We are starting with 3 sample points in the range 8 11 GHz This will place 1 point at 8 9 5 the supposed resonance and 11 GHz Click the Recalculat
332. simulation analyzes the static operating points DC voltages and currents at each nonlinear node and port in the circuit When designing circuits using non linear models you should always check the DC operating point before doing linear or harmonic balance simulations DC analysis is very fast and will make sure that you have entered a workable design Note DC Simulation is not generally the same as the DC zero frequency level from a harmonic balance simulation In DC simulation all AC sources are turned off Nonlinear device models have many parameters that can be entered in error To make sure that the model is correct it is a good idea to look at the DC characteristic curves of the device before entering a complete circuit Workspace templates are available Select New From Template from the File Menu then BJT Test wsp that make it easy to create these curves In addition to analysis DC results can be optimized For example you can optimize bias resistor values to achieve a desired collector current and voltage for a bipolar transistor See the walkthrough DC Analysis Verifying Transistor Parameters for an example It is located in one of the following sections To add a DC simulation 1 Right click the Simulation Data node on the Workspace Window 2 Select Add DC Analysis 3 Complete the DC Analysis Properties dialog box For details see the Reference manual To open double click or create a DC Simulation 41 Sim
333. smitted energy traveling from node to node along the specified path See the Transmitted Energy section for additional information 87 Simulation 88 Composite Spectrum Composite spectrum is unique feature in SPECTRASYS A composite spectrum allows the user the ability to view full node spectrums and identify the spectral component origins and their path of travel to the designated node There are three general spectral categories in SPECTRASYS They are 1 Signal 2 Intermods and Harmonics and 3 Noise Furthermore each source and their derived components harmonics intermods spurs etc will be propagating in all directions when then arrive at a node The makeup of composite spectrum consists of a trace for each 1 Element representing the total power traveling from that element into the node 2 Signal component 3 Intermod and harmonic component 4 Noise component Because of the way that SPECTRASYS keeps track of these spectral components independently and each component is represented by a trace on the graph it is not uncommon to have hundreds and even thousands of spectral components traces at a single node The user can determine which of the spectral pieces they would like to see On the Composite Spectrum tab of the System Simulation dialog box the user can check or uncheck which pieces of the spectrum they would like to see The total from each element will always be shown and cannot be disabled Furthermore all spe
334. ss the R key again or the Space Bar and place R2 as shown below Make R2 100 also Walkthrough DC Linear HARBEC 8 Press the W key to place a wire and connect R2 to the transistor base The schematic should look as shown below JP GENESYS 7 5 DC Bias Workspace HB2 File Edit View Workspace Actions Tools Schematic Synthesis Window Help aj x Dm Bro 89 pA aal TOBA Lumped Linear Nonlinear T Line Coax Microstrip Slabline Stripline Wave z aR R 100 ohm s IC IDC 0 017A m 3 Designs Model 4 Ex DC Bias Sc yd Amplifier Sc Ly DC Curves E E3 Simulations Da DC i se A HE1 Amplif E IB Sweep I 8 YC Sweep i3 L Za put Powe Z of Ready Error 0 0151035 9 Inthe Workspace window under Simulations Data right click on the VC Sweep and de select the Active for Opt Yield to turn this off Do the same for the IB Sweep This will prevent these sweeps from calculating during the optimization we are about to perform 10 In the Workspace window right click on Optimizations node and select Add a Set of Targets 11 Accept the default name 12 Enter the following e Default Simulation Data or Equations DC1 DC Bias use down arrow and select from list e On the first line enter Measurements v2 Op Target 2 5 Weight 1 Min 0 Max 0 e On the second line enter Measurement tic Op Target 0 01 We
335. ssion minContour maxContour stepSize smoothParm minX maxX minY maxY primaryGridSize secondaryGridSize Generates contour plot of 2D data expression on a Smith Chart Expression is a mandatory parameter the remainder are optional parameters Expression must contain coordinates real imag and values for a given measurement and a Thin Plate Spline is generated from which the contours are generated The smoothParm is generally a number between 0 no smoothing and 1 very strong smoothing minX maxX minY and maxY control the domain for which data is generated primaryGridSize and secondaryGridSize control the resolution of the contour generation primary should be a smaller number than secondary COS expression cosine COSH expression hyperbolic cosine COUNT expression returns the number of data points contained in post processed data or the size of an array See Arrays or Post Processing later in the equations reference DB10 expression returns 10 log expression DB20 expression returns 20 log expression EXP expression value of e raised to expression FIX expression truncates the expression Examples FIX 5 6 is 5 and FIX 1 4 is 1 FN_E expression Calculates the complete elliptic integral of the second kind FN_K expression Calculates the complete elliptic integral of the first kind GET string Gets a measurement from a string variable Can be useful for constructing a measuremen
336. st Remember absolute node impedance and resulting measurements based on that impedance don t make any sense since they are totally dependent on the which direction from which we look into the node Path 1_2 Path 3 2 Transmitted Energy SPECTRASYS System Transmitted energy is only the energy flowing in the forward direction For example lets suppose that we have a fixed attenuator of 3 dB in series with a bandpass filter that has 50 dB of rejection at 1 GHz which is outside the passband of the filter Now lets suppose that we are going to look at the power level of this out of band 1 GHz signal along the path from the attenuator input to the output of the bandpass filter Intuitively we would expect to see 3 dB of attenuation of the 1 GHz signal across the 3 dB pad and then and additional 50 dB of rejection across the filter However when we closely examine the impedances and power levels at each node we see things in a slightly different light 1 The input impedance of the 3 dB pad will not be exactly 50 ohms since its load impedance is the input impedance of the bandpass filter at the input frequency of 1 GHz which can be very low or very high Consequently if the applied power level is 0 dBm then the actual power level that will be transmitted through the attenuator node 1 power will be lower than the applied power 2 Since the input impedance of the bandpass filter at the out of band frequency of 1 GHz can be very h
337. sweeping receiver that peak detects the total power within the resolution bandwidth For the analyzer mode the user can specify the resolution bandwidth of this sweeping filter The default resolution bandwidth is the Measurement Channel Bandwidth if no value has been specified Filter Shape This parameter determines the shape of the resolution bandwidth filter that is used for integration This filter shape is analogous to the resolution bandwidth filter shape in a spectrum analyzer However a brickwall filter can be created theoretically and is implemented in the software as a user selection Furthermore a more realistic filter can also be selected which is created from a Gaussian 3 element lowpass prototype The user is able to select three widths for this particular filter which are based on an integer number of channel bandwidths No spectrum integration will occur outside the width of this filter This filter width is used to reduce the amount of data collected saved and processed by SPECTRASYS Brickwall Ideal This filter is an ideal rectangular filter whose skirts are infinitely steep Gaussian to 100 dBc 30 Chan BW Data will be ignored that is farther than 30 channels away from the center frequency With this 3 element lowpass prototype the attenuation 30 channels from the center will be about 100 dBc Gaussian to 117 dBc 60 Chan BW Data will be ignored that is farther than 60 channels away from the center
338. t Can be safely edited Yes EMPOWER File Descriptions Average size 1 to 5Kbytes Use Describing circuit to EMPOWER This file contains a complete description of the circuit to be analyzed by EMPOWER GENESYS will create this file automatically whenever EMPOWER is run from the EMPOWER menu in GENESYS Even though this files can be edited it will be overwritten if EMPOWER is rerun from within GENESYS Written by GENESYS Type Binary Can be safely edited Yes but only using GENESYS Average size 10 to 2 000 Kbytes Use Contains complete simulation graph schematic and layout information from GENESYS Contains a complete GENESYS workspace Written by GENESYS Type Binary Can be safely edited No Avetage size 2 to 25Kbytes but may be larger Use Internal data file for EMPOWER This file contains the calculated Y parameters before deembedding If merge ME is specified the previous data stored in this file is combined with the newly calculated data and the SS S Parameter file is rewritten All files with a name or an extension starting with tilde are backup files and can be safely deleted Examples of these files are OMBINE TPL and COMBINE RG 305 EMPOWER References J A Stratton Electromagnetic theory McGraw Hill Co New York 1941 G Kron Equivalent circuit of the field equations of Maxwell Part I Proc of IRE 1944 May p 289 299 C G Montgomery R H Dick E M Purcell Princip
339. t and recommended method is to use the LAYOUT program to create a graphical representation of the desired layout pattern The board can then be simulated by creating an EMPOWER Simulation This chapter describes how to use the LAYOUT program to construct a board layout and obtain an EMPOWER simulation GENESYS is then used to display and compare the linear simulation with the EMPOWER data EMPOWER incorporates many features still not present in competitive late generation EM simulators Principle features include e Benchmarked accuracy e Easy to use graphical circuit layout editor e Complete integration with the GENESYS circuit simulation synthesis and layout tools e Multilayer simulations with EMPOWER ML e Automatic incorporation of lumped elements e Automatic detection and solution with symmetry e Generalized S parameter support e Multi mode support for ports and lines e Tuning of EM objects in GENESYS using decomposition e Deembedded or non deembedded ports e Viaholes including generated fields e Any number of dielectric layers e Dielectric and metal loss e Includes box modes and package effects e Slot mode for slot and coplanar circuits e Thick metal simulation with EMPOWER ML e 32 bit code for Windows 95 98 NT 197 Simulation 198 The examples are completely contained in the EXAMPLES manual Examples which illustrate EMPOWER include e Microstrip Line WSP e Stripline Standard WSP e Spiral
340. t Frequencies This checkbox enables frequency limiting of the analyzer mode By default the entire spectrum from the Ignore Spectrum Frequency Below lower frequency limit to the highest frequency limit of Ignore Spectrum Frequency Above will be processed by the analyzer for every node in the system In some cases this may be very time consuming In order to improve the simulation speed and just process the area of interest frequency limits can be enabled to restrict the computation range of the analyzer Start This is the beginning frequency of the analyzer Stop This is the ending frequency of the analyzer Step This is the frequency step size between analyzer data points The step size can be reduced until the maximum number of simulation points of 20 000 is reached Number of Simulation Points The number of simulation points used for the graph is determined internally in SPECTRASYS This parameter cannot be changed by the user Since SPECTRASYS can deal with large frequencies ranges the amounts of data collected for a single spectrum analyzer trace could be enormous Furthermore the analyzer function is not a post processing function and the number of simulation points cannot be changed without rerunning the simulation In order to better control the amount of data collected which is proportional to the simulation time SPECTRASYS internally determines the number of simulation points to use Simulation Speed Ups During th
341. t Input Fort fi k Include Signal Signal Type Modulated New Custom Source with Phase Noise Wie Edit Center Frequency 100 MHz Step and Repeat Signal Bandwidth fi MHz Frequency Offset ji MHz Power Average o dEr Amplitude Offset o dE o gt 5 Phase Shift 0 l Phase Offset Number of Signals Number of Simulation Points Broadband Noise fi Start Frequency jo MHz Power pi rd dEm Hz fico jo Stop Frequency MHz Number of Points When enabled for any source on a port broadband noite i used instead of thermal noise at that port Cancel Apply Help 5 Press OK to close the Source box 6 On the first Forward Path line in the Paths tab enter 100 for the channel frequency This is necessary because we now have many signals coming into the input and we need to specify which one to track for the level diagram 7 Click OK to close the system dialog and start simulation 8 Zooming in on the input and output will show the following spectra You can either use a mouse wheel or the zoom icons on the toolbar Notice all of the junk coming in and out of the circuit 27 Simulation Workspace 7 Multiple Signals Output Spectrum 2400 mE eee i E E E EN EE a AA A A O O E M SSI SSS SS SSS ESS SSS ESS dd E al SE SS eee A EEE E EEE EEE SSS SSS A ee SS SSS qs Pa e 00 0 EOGOEEEEOEE EE OE pEpuUEEOo C O meme
342. t base 1s 1 meaning that the first data point in an array is accessed using the number 1 The statement can appear more than once in an EQUATION window A new base statement changes the beginning index of all arrays whether they were defined before or after the base statement The form of the statement is BASE 0 or BASE 1 Viewing Variable Values Values calculated in the EQUATION Window may be viewed to verify that the equations yield expected results Right click on Data Outputs in the Workspace Window and select Add Variable Viewer Operators 106 Operator descriptions in precedence order are Operator Meaning Comments Array Index Exponentiation Raises a number to a power For example 2 3 is 8 and 3 2 is 9 Multiplication Division Integer Division The quotient is truncated to an integer result For example 1013 is 3 and 3 4 is zero Modulo The numbers are divided and the remainder is returned For example 10 3 is 1 and 7 6 2 is 1 6 Addition E Subtraction Equality Check Left and right values are compared If the results are equal the value is 1 true otherwise the value is zero false For example 1 1 2 gives 1 and 1 1 3 gives zero gt Greater Than lt Less Than gt gt Greater Than or Equal lt lt Less Than or Equal Not amp And Or Array Concatenation Sample Expressions Expression 15423 1 2 3 4 3 3 4 3 19 4 19 4 19 4 Plo 2 5 gt 4
343. t from pieces of text See Post Processing later in the equations reference GETINDEPVALUE exptession index dim returns the independent data point for dimension dim of a post processed expression See Post Processing later in the equations reference Note If the independent data is frequency GETINDEPVALUE returns the values in Hz not MHz GETVALUE expression index calculates and returns a value of a post processed expression See Post Processing later in the equations reference Equation Reference GETVALUEAT expression indep calculates and returns a value of a post processed expression at a given independent value Only works on 2 dimensional data X vs Y See Post Processing later in the equations reference Note If the independent data is frequency GETINDEPAT requires values in Hz not MHz IFF condition trueValue falseValue returns trueValue if condition is true and falseValue if condition is false Can be used with any data including post processed data IFTRUE condition trueValue returns trueValue if condition is true and zero if condition is false Can be used with any data including post processed data IMAG expression returns the imaginary part of a complex number Alternate form IM expression INT expression greatest integer less than or equal to the expression Examples INT 5 6 is 5 and INT 1 4 is 2 LOG expression base 10 logarithm LN expression natural logarithm MATRIX row
344. t of e is k c f P MHP nmp l 27 y E where c is the velocity of light in a vacuum 2 997925x104m sec The frequency of the dominant mode is 7o7 lowest resonant frequency and in a vacuum we have j c l 1 ol Aa E 2 a b In air with linear dimensions in inches and the frequency in megahertz l fio 5900 MHz e inches gt va b 283 Simulation 284 With linear dimensions in millimeters and the frequency in gigahertz 11 fio 149 8GHz o mm 101 a h For example in air er 1 0006 with a 24 inch 0 5 inch high box b 101 6mm a 50 8mm and h 12 7mm Then amp 791 69 14 and fio1 3297 MHz It is interesting to note that if h lt a and lt b then the frequency of the dominant mode is not a function of the cavity height This is not the case for certain higher order modes The mode which is next higher in frequency than the dominant mode is a function of the relative values of a and b Consider for example the previous 2x4x0 5 inch box or any size box with the size ratios b 2a and 1 4 Therefore the wave numbers ate TN kmp m 160 E Cl 4 j The wave numbers for the lowest frequency modes for this shape box and the resonant frequencies with a 2 inches are listed here Mode Wave 101 3299 102 4173 103 5319 201 2 062pi a 6083 104 2 236pi a 6598 105 2 693p1 a 7945 301 3 041p1 a 8974 106 3 162pi a 9331 Notice that higher order modes occur
345. tegrated total intermod power in the main channel conducted from the prior stage during the IM3 analysis pass Only Intermod signals ate used for this measurement All other types of signal are ignored This measurement will include all intermods that are traveling in the forward path direction In equation for the conducted third order intermod power is CIM3P n TIM3P n 1 GAINIM3 n where CIM3P 0 0 dB and n stage number Using this measurement in conjunction with the Generated Third Order Intermod Power GIM3P and the Total Third Order Intermod Power TIM3P the user can quickly identify the weak intermod link in the cascaded chain and will guide the user in maximizing the Spurious Free Dynamic Range SFDR Note The Calculate IIP3 TOD checkbox must be checked and properly configured in order to make this measurement See the Calculate IIP3 TOD section for information on how to configure these tests See the Total Third Order Intermod Power and GainIM3 measurements to determine which types of signals are included or ignored in this measurement In the Calculate IIP3 TOI Manual Mode since a dedicated IM3 analysis is not created and the normal analysis is also the IM3 analysis pass Remember intermod bandwidth is a function of the governing intermod equation For example if the intermod equation is 2F1 F2 then the intermod bandwidth would be 2BW1 BW2 Note Bandwidths never subtract and will always add The
346. ters Paths Tab Many measurements require the definition of a path For an overview of Paths see the Paths section later in the Simulation manual Two functions exist on the System Simulation dialog box shown below to aid the user in specifying the path The first is an Add Primary Paths button All possible port to port paths will be added to the System Simulation for all ports that have a source defined If no sources have been defined then no paths will be added If the number of paths becomes very large then the user will be prompted before adding the paths The second is an Add Path button which will prompt the user for the 1 Path Name 2 From Node and 3 To Node 97 Simulation 58 System E Parameters Channel TEP nee at Start Node MHz Add All Paths From All Sources Automatically adds all possible paths between inputs ports with signal sources and input output ports all ports Add Path Invokes a wizard to assist the manual creation of a path Name Specifies the path name This name is used in output graphs to select the path s data Path from Node thru Node to Node a sequence of node numbers is specified here The system simulator chooses the shortest path which goes through the specified nodes in order Channel Frequency MHz Specifies the path frequency at the start node By default this parameter is blank which means that SPECTRASYS will use the frequency o
347. th ideal match of source impedance i e Ys Yopr Values Real value versus frequency Simulations Linear Default Format Table dB Graph dB Smith Chart none Commonly Used Operators Operator Description Result Type DB NF noise figure in dB Real MAG NF magnitude of the noise figure Real Examples Measurement Result in graph Smith chart Result on table optimization or yield NE DB NF DB NF MAG NEMIN magnitude of the minimum noise figure magnitude of the minimum noise figure Not available on Smith Chart A noise circle is a locus of load impedances for a given noise figure as a function of frequency This locus is plotted on a Smith chart with noise figure degradations of 0 25 0 5 1 0 1 5 2 0 2 5 3 0 and 6 0 dB from the optimal noise figure Note See the section on S Parameters for a detailed discussion of noise circles Values Complex values versus frequency Simulations Linear 153 Simulation 154 Default Format Table center MAG ANG radius Linear Graph none Smith Chart Circles 6 Commonly Used Operators None Examples Measurement Result in graph Smith chart Result on table optimization or yield NCI noise circle locus of load impedances for optimal noise figure for each circle center MAGT ANGI radius Linear Available on Smith Chart and Table only The noise correlation matrix elements are complex functions of frequency The frequency range and inte
348. the Desired Channel Power output of the prior stage as shown by GAINIM3 n DCPIM3 n DCPIM3 n 1 dB where GAINIM3 0 0 dB n stage number See the Desired Channel Power Third Order Intermod Analysis measurement to determine which types of signals are included or ignored in this measurement The only difference between this measurement and the Gain GAIN measurement is that this measurement applies to the IM3 analysis pass only Consequently this will be the same measurement as GAIN in the Calculate IIP3 POD Manual Mode since a dedicated IM3 analysis is not created and the normal analysis is also the IM3 analysis pass Remember intermod bandwidth is a function of the governing intermod equation For example if the intermod equation is 2F1 F2 then the intermod bandwidth would be 2BW1 BW2 Note Bandwidths never subtract and will always add The channel bandwidth must be set wide enough to include the entire bandwidth of the intermod to achieve the expected results The Automatic Intermod Mode will set the bandwidth appropriately Values Real value numeric 181 Simulation 182 Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DB GAIN gain in dB Real MAGJ GAIN numeric value of the gain Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DB GAIN DB GA
349. the upper noise frequency limit Simulation Speed Up As with any other type of simulation the larger the number of spectral components that need to be processed the more time the simulator will take Setting these limits to only calculate the frequencies and amplitude ranges of interest can speed up the calculation process especially when calculating intermods However take caution when setting these limits so that intentional spectrums are not ignored User Defined Offset Channel This group is only used in conjunction with the Offset Channel Frequency and Offset Channel Power measurements Freq Offset From Channel This is the relative frequency offset from the current channel frequency Measurement Bandwidth This is the integration bandwidth for the Offset Channel Power measurement See Offset Channel for additional information Maximum Number of Spectrums To Generate This group is used to limit or restrict the maximum number of spectrums that will be created by SPECTRASYS Max Spectrums Limits the maximum number of spectrums that SPECTRASYS will create Once this limit is reached during a simulation no additional spectrums will be created This option must be used with care since a premature limitation of the number of total spectrums may affect the accuracy of the measurements Range Warning for Mixer Multiplier etc This group is used to control range warnings used by some elements in SPECTRASYS To
350. this dialog box can be made tunable by placing a in front of the parameter System Simulation Parameters General Paths Calculate Composite Spectrum Options Ignore Spectrum User Defined Offset Channel Level Below 200 dBm Frequency Below fo MHz Frequency Above 75000 MHz Frequency Above and Below are optional The default Frequency Below is 0 and the Frequency Abowe defaults to 5s Mas Source Freq Offset From Channel 1100 MHz Measurement Bandwidth fi MHz Thiz info is only used by the OCF and OCP Offset Channel Frequency and Power measurements ara i M asinurn Number of Spectrum To Generate Max Spectrums Range Warning for Mixer Multiplier etc Tolerance Range 2 dB gt Factory Defaults Cancel Apply Help Ignore Spectrum This group is used to limit or restrict the number of spectrums created by SPECTRASYS These thresholds apply at every calculated node Consequently if a signal is heavily attenuated or outside the given frequency range during a portion of the path and are then amplified or frequency translated back into the given frequency range then these thresholds must be set so that the spectrums will not be ignored along the calculation path Once an individual spectrum is ignored it will not continue to propagate However all spectrums previously calculated will still be available at the nodes where there were within the specified
351. tion Changing this parameter has three and only three effects 1 The maximum amount of thinning out is affected EMPOWER will thin out until an area is 1 20th of a wavelength at this frequency in the default thinning mode 2 The length of line analyzed for deembedding is 1 2 wavelength at this frequency in automatic mode 3 Many parameters in the listing file are based on this frequency The most important thing to know about maximum critical frequency is to keep it the same between runs of the same problem even if you are changing the frequency range which you are analyzing If it is changed then the thinning out is changed and the entire problem geometry is slightly different As an example if you are analyzing a filter with a passband from 5 1 to 5 5 GHz with a reentrance mode additional passband around 15 GHz you should probably set the maximum critical frequency to 5 5 GHz This is because the exact characteristic of the reentrance mode probably is not important critical you just want to know approximately where the filter re enters On the other hand you want to know precisely where the passband is so you set the maximum critical frequency above it The effect of maximum critical frequency is generally secondary Most of the other choices in the table above have a bigger effect on accuracy Making a problem exactly symmetrical is an easy way to make a problem require less memory and time without sacrificing any acc
352. tion of the boundary conditions for the media layer interfaces A 2 are given in the following table 2 Lossless metalization _ H r Port Region along X Axis or Internal Port Lumped Element Region along X Axis the same for y axis C is region cross section lis region length A 2 289 Simulation 5 Internal Port along Z axis J i ddy Y JB a C l Input ports in the structure are modeled by line segments approaching the outer boundaries line conductors and surface current sources in the regions where line conductors approach the walls of the volume It is assumed that the currents inside the input and the lumped element regions are constant in the direction of current flow and the corresponding electric field component along the region is constant across it Thus the integral of current across the region gives an integral current and integral of the electric field along the region gives an integral voltage for the region The desired solution of the electromagnetic problem is an immitance matrix relating the integral voltages and currents in the port and lumped element regions This is actually a kind of Green s function contraction on the port and lumped element regions After connection of the lumped elements the immitance matrix can be transformed into a generalized Y or S matrix using the simultaneous diagonalization method see the de embedding section Thus we have a problem formulation that is
353. to the selected view The settings can be restored later by selecting the desired from the load sub menu described above The options in this menu can also be selected by pressing Shift the number key corresponding to the desired save 267 Simulation 268 Tip The save and load functions are extremely useful If you rotate and pan to a view that you like press Shift plus a number not an arrow to save that view Simply press the number by itself to return to that view These views are remembered even if you exit the viewer so you can easily store your favorite views C X Y Z XY Button Pressing this button toggles between the four possible modes X Displays the x directed current density distribution Y Displays the y directed currents density distribution Z Displays the z directed currents XY Displays additive surface current density distribution function D Animate Button This button toggles viewer animation on the current image When this option is selected the button appears pressed The viewer animation is accomplished by multiplying the individual currents by exp jw where w cycles from 0 to 2p1 and plotting snapshot graphs for sequential time moments What is animated is controlled by the Display Option Button see E below E Display Option Button This button selects the current display option Real Displays the real portion of the current values Mag Displays the magnitude or time aver
354. tomatic recalculation is on and a simulation is needed the simulator will run after the box is dismissed Cancel Dismiss the dialog box canceling any changes made HARBEC Options General Advanced Oscillator Relative Tolerance MIESE Absolute Tolerance le 12 Maximum Amplitude Step oo to loci 6 Frequency Resolution E Hz Reuse Jacobian at Most 1000 Times Full Jacobian Automatic i Use Previous Solution 45 Starting Point Set All Fregs as Harmonics of Force 1 D FFT Allow pseudo harmonic FFT calculation Allow non binary FFT Minimum Amplitude Step FFT Use Krylov Subspace Method Special Options coca ee Advanced Tab Convergence Parameters Refer to Optimizing Simulation Performance in the User Manual for details on the convergence process and the use of the parameters described below Relative Tolerance The relative accuracy to which the sum of node currents must sum to zero to achieve harmonic balance convergence The simulator is converged if for all frequencies and all nodes the ratio of the vector sum of the currents into a given node currents to the sum of magnitudes of the current entering that node is less than the specified relative tolerance 46 HARBEC DC amp Harmonic Balance Absolute Tolerance The absolute accuracy to which the sum of node currents must sum to zero to achieve harmonic balance convergence The simulator is converged if th
355. tput P1dB Saturation Power IP3 and IP2 intermods and harmonics will be created See the Calculate Intermod and Harmonics section for additional information Frequency Rolloff All signals intermods and harmonics will be attenuated as a function of frequency according to the attenuation slope that begins at the the corner frequency NOTE Noise will bypass this step and will not be rolled off with frequency Reverse Isolation for Internally Created Intermods and Harmonics Once intermods and harmonics have been created and rolled off with frequency these intermods and harmonics will appear at the amplifier input and continue to propagate backwards through the system Reverse Isolation for Reverse Traveling Signals Reverse isolation will be applied to all reverse traveling signals that encounter the amplifier output before its input Channel Channelized Measurements and Measurement Bandwidth 68 SPECTRASYS System Over 30 different types of measurements are available for SPECTRASYS Many of these measurements integrate spectrum power A frequency and bandwidth are required in order for SPECTRASYS to know where to integrate the spectrums The Channel Frequency specifies the center integration frequency and the Measurement Channel Bandwidth specifies the range of frequencies to integrate over For example if a power amplifier was designed for a 5 MHz carrier operation in the 2 GHz band then you must set the Measur
356. trol of the LO drive level of each mixer and a global system simulation parameter that will check that the LO power is within a user specified widow of the LO drive level The user specified mixer LO parameter is the Mixer LO Range specified on the Options tab of the System Simulation dialog box During system calculations SPECTRASYS will integrate the entire LO spectrum power and this power will be compared to the mixer LO drive level If this LO power is outside the specified LO range a local error will be created and the mixer will change color indicating to the user that a potential error has occurred in the mixer Desired Output The Desired Output mixer parameter is only used by SPECTRASYS to determine the desired channel frequency along a path defined through the mixer This parameter does not affect the operation of the mixer in any way LO Drive Level The LO Drive Level parameter is currently only used by the mixer to determine if the target LO power level of the mixer This information combined with the Warning Range on the Options Tab in the System Simulation Dialog Box is used to warn the user if the mixer is being starved or over driven SPECTRASYS System Noise Arriving at the RF and IF Ports A noise source is treated just like any other sional source However since this is currently a time independent simulator noise will not create intermods harmonics and be used with reverse isolation Broadband No
357. tup E Filename e teagleteramplesimrf301 615 Browse _ Cancel Number of Ports 2 Filename Specifies the file containing the Device Data to load Browse Opens a File Open Dialog box so that you can locate the desired data file Number of ports Specifies the number of ports the data file has Provided Device Data GENESYS includes over 25 000 data files for many different device types Device data was provided directly by the manufacturers in electronic format Caution Eagleware could not test every file that was provided Through random sampling we edited errors found in some files It is the user s responsibility to test each file for accuracy Creating New Linear Data Files 120 You may easily add other devices to the library by using a text editor such as NOTEPAD to type the data into a file with the name of your choice Be sure to save the file in standard ASCII format The first line in the file after any initial comments is a format specifier in the form units type format R impedance where Device Data units is either Hz kHz MHz or GHz type is the type of the data file either S Y G H or Z format is DB for dB angle data MA for linear magnitude angle data or RI for real imaginary data impedance is the reference impedance in ohms commonly 50 or 75 One of the most common format specifiers is MHZ SMA R 50 This indicates that the data is in S parameter form normalized to 50 ohms
358. tute the problem with solution defined in a space of continuous functions by a problem with a solution defined in a discrete space The model solution must be as close to the continuous one as possible To solve the problem we approximated the partial derivatives in the signal plane by finite differences applied to grid analogues of the field components The corresponding grid is shown here 291 Simulation 292 There are L 1 equidistant cells along the x axis and M 1 cells along the y axis The grid equivalents of the electric e and magnetic h fields are defined as corresponding continuous function values in offset grid points as is shown for a grid cell above The grid functions are continuous along the z axis Grid x and y directed current variables Jx Jy are defined as integrals of the surface current in the metal plane across the grid cell Grid z directed currents Jz are defined as surface integrals of the volume current density jz across the erid cell The first offset model of Maxwell s equations was apparently proposed by G Kron 1944 The cells below show a summary of the similar models implemented by different authors The resultant system of differential difference equations approximates the initial system with the second order locally inside a layer The initial boundary value problem can contain infinitesimally thin metal regions with consequent singularities of the field and conductivity currents at the metal edges M
359. tween the metal layers All metal layers from the General Layer Tab are also shown in the EMPOWER Layer tab These layers are used for metal and other conductive material such as resistive film The following types are available e Lossless The layer is ideal metal e Physical Desc The layer is lossy These losses are described by Rho resistivity relative to copper Thickness and Surface Roughness e Electrical Desc The layer is lossy and is described by an impedance or file This type is commonly used for resistive films and superconductors If the entry in this box is a number it specifies the impedance of the material in ohms per square If the entry in this box is a filename it specifies the name of a one port data file which contains impedance data versus frequency This data file will be interpolated extrapolated as necessary See the Reference manual for a description of one port data files e SCHEMAX substrates Choosing a SCHEMAX substrate causes the layer to get the rho thickness and roughness parameters from that substrate definition We recommend using this setting whenever possible so that parameters do not need to be duplicated in SCHEMAX and LAYOUT Caution Thickness is only used for calculation of losses It is not otherwise used and all strips are calculated as if they are infinitely thin Metal layers have three additional settings available Slot Type Check this box to simulate the non lossless metal areas
360. u use generalized S Parameters With generalized S Parameters instead of the ports being terminated with 50 or 75 ohms the ports are terminated with the characteristic impedance of the line as calculated by EMPOWER This is a more internally consistent representation and the results are often far more accurate You should use generalized S Parameters if the following three conditions hold 1 You are using normal deembedded ports Ports marked No Deembed or Internal are not appropriate for reporting generalized S Parameters so they are normalized to 50 ohms if generalized parameters are requested 2 You have calculated the impedance of the lines at the ports using T LINE for instance and they are 50 or 75 ohms 3 You have run EMPOWER but it calculated the port impedances to be a little different for example 47 instead of 50 ohms This error is generally a result of the grid size A finer grid would result in less error in the impedance In this case you know that your port lines should be 50 ohms but EMPOWER reported 47 ohms If you then request Generalized S Parameters GENESYS will also use 47 ohms for the terminating impedance and a large part of the analysis error due to the grid will be cancelled The results will be close to the results obtained if you measured the circuit in a 50 ohm network analyzer To get generalized S Parameters from GENESYS Check the Generalized box in the EMPOWER properties dia
361. uation Window An example function to calculate the inductance that resonates with a capacitor at a given frequency Equation Reference FUNCTION RESL C F L is in nH C is in pF F is in MHz FHz 1e6 F CFarads 1e 12 C Omega 2 PI FHz LHenties 1 Omega Omega CFarads Return LHenries 1e9 An example which uses this function is L RESL 100 50 Find L to resonate 100pF at 50 MHz You could also type RESL 100 50 into a part value in SCHEMAX Functions should go at the end of the global equations in your workspace If you have functions you want to save permanently save your workspace in the EAGLE MODEL directory Multiple functions can be placed in one file The functions will then be automatically loaded when GENESYS is started For advanced uses you can pass variables by reference which means that the function can directly modify the variables passed in To pass a variable by reference put the word BYREF in front of the name For example FUNCTION DOUBLE BYREF X BYREF Y X X 2 Y Y 2 RETURN 0 Calling this function doubles the variables passed in For example A 5 B 6 IGNORE DOUBLE A B After this call A 10 and B 12 Notice that all functions must return a value even if you will ignore it as in this case GENESYS has the capability to call programs you have written The techniques for doing this are beyond the scope of this manual If you are interested in this capability contact Eaglewate and we will be happy
362. uctures Sestrorezkiy Kustov Shlepnev 1988 that cotrespond to a combination of the 3D finite difference approach and the spectral domain technique Later only the discretisation in the metal plane was left but the method still retains some advantages of the network impedance analogue method That is why we sometimes refer to the EMPOWER numerical techniques as the impedance interpreted method of lines 290 EMPOWER Theory Here are the main solution stages of the impedance interpreted MoL Partial discretisation of the Maxwell s equations only in the plane of metalization x y plane Grid spectral representation of the EM fields in the homogeneous layers Building Grid Green s Function GGF matrix in spectral domain using impedance form of the solution in a layer Representation of each GGF matrix element as a sum of four elements of an auxiliary array obtained using DFFT technique Equidistant grid transformation to a non equidistant grid using thinning out and linear re expansion procedures Automatic detection of symmetry for symmetrical and nearly symmetrical y ern y sy problems reflection and 180 rotational Solution of the main system of linear algebraic equations using partial inversion Resolution to Y or Z matrix relating integral grid currents and voltages in the input and lumped element regions To map a boundary value problem for a partial differential equation on the grid basically means to substi
363. ue is used instead If two matrices of different sizes are added then the operation is only performed up to the size of the smallest matrix These operations are performed as if the matrices were vectors see the example of linearly accessing a matrix as a vector above All operators and builtin functions will work properly on arrays so for example taking the hyperbolic sine of matrix A using SINH A will take the hyperbolic sine of each element of A Also arrays can be passed to user models and functions so you can create a user model that takes a matrix or vector as a parameter Strings can be used in vectors and the addition operator will work For example J VECTOR J 1 One J 2 Two J 3 Three K Element M J K M 1 Element One M 2 Element Two etc Note Vectors and matrices are now base one in GENESYS first element is number one To use base zero put the statement BASE 0 on a blank line at the top of your equations and at the top of any function To find out how many elements an array has use the COUNT function N VECTOR 71 P COUNT N P 71 Q MATRIX 100 75 R COUNT Q R 7500 One of the more powerful features of the GENESYS Equation Window is post processing sometimes referred to as Output Equations This allows you to perform calculations on the results of your analysis These results can then be displayed optimized or even used in another design For example Gain Linearl Filter DB S2
364. ulation 42 DC Analysis Properties Ea Simple Detector Do loo W Automatic Recalculation Design Names of the designs found by GENESYS Annotate When checked DC voltages will be labeled on the schematic at all nodes connected to a nonlinear device a source a voltage test point a current probe or a port In addition DC current will be written to each current probe for display Only schematics support back annotation of DC values For netlists and EMPOWER simulations place DC measurements on a tablular output to see the circuit operating point Options Area to place DC simulator control parameters usually left blank OK Dismisses the dialog box If automatic recalculation is on and a simulation is needed the simulator will run after the box is dismissed Cancel Dismiss the dialog box canceling any changes made Automatic Recalculation Checking this box will cause the DC simulation to be run any time there is a change in the design If the box is not checked the simulation must be run manually either by right clicking on the simulation icon and selecting Recalculate Now or by clicking the recalculation button on the main tool bar DC Simulator options These options are available for advanced applications and are normally not necessary Gmin Changes the value of conductances added to each nonlinear node in the circuit The simulator by default attaches a 1 pico siemens conductance 1 teraohm resistor b
365. ulations and to increase accuracy of solutions For these reasons and others we decided to use it for the 287 Simulation 288 electromagnetic simulator This section summarizes the theoretical backgrounds with emphasis on the problem formulation and acceleration techniques Most commercial electromagnetic EM simulators designed for MIC and MMIC work are based on integral equations and the method of moments MoM EMPOWER is based on the method of lines MoL This technique has excellent error convergence properties and submits well to code optimization to minimize numeric complexity The root of EMPOWER is work which began in 1987 at the Novosibirsk Electrical Engineering Institute This lead to the commercial development of TAMIC in 1991 in Moscow TAMIC saw commercial use in the Soviet Union and elsewhere In late 1996 Eaglewatre acquired TAMIC and the principle contributor joined Eagleware to begin significant improvements The code was integrated into the GENESYS environment at release Version 6 5 in 1998 This section describes a general mathematical formulation of the boundary value problem to be solved It defines all restrictions in the problem domain You can use this section to decide whether your particular problem fits the formulation or not For analysis a passive MIC structure is confined inside a three dimensional rectangular volume bounded by electric or magnetic walls The volume is filled by a layered medium that ma
366. ult Type DBM TCP tone channel power in dBm Real MAG TCP magnitude of the tone channel power in Watts Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DBM TCP DBM TCP DBM TCP MAG TCP MAG TCP MAG TCP Not available on Smith Chart This measurement is the individual stage gain of the main channel along the specified path The Gain is the difference between the Desired Channel Power output of the current stage minus the Desired Channel Power output of the prior stage as shown by Measurements SPECTRASYS GAIN n DCP n DCP n 1 dB where GAIN 0 0 dB n stage number See the Desited Channel Power measurement to determine which types of signals are included or ignored in this measurement Values Real value numeric Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operators Operator Description Result Type DB GAIN gain in dB Real MAGJ GAIN numeric value of the gain Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DB GAIN DB GAIN DBI GAIN MAG GAIN MAGIGAIN MAG GAIN Not available on Smith Chart This measurement is the individual stage gain of the main channel along the specified path during the IM3 analysis pass The Gain is the difference between the Desired Channel Power Third Order Intermod Analysis output of the current stage minus
367. uracy There are four types of symmetry recognized by EMPOWER YZ mirror symmetry XZ mirror symmetry two mirror symmetry and 180 rotational symmetry These types are illustrated below EMPOWER Tips YZ Mirror XZ Mirror Two Mirror Rotational When EMPOWER is running you should look at the information area at the top of the screen to see if symmetry is active If it is not recheck your problem to see if it is exactly centered on the box and to see if it is in fact symmetrical Two tools can help with this 1 Using Center Selected on Page from the Edit menu in LAYOUT This command makes it easy to make sure that your circuit is exactly centered on the page 2 Showing the listing file by selecting Show Listing File from the EMPOWER right click menu This file shows exactly how the problem was put on the grid and lack of symmetry is often obvious Making an unsymmetrical problem symmetrical will make it run 4 times faster in most cases and will make it 16 times faster if your problem can use two mirror symmetry See EMPOWER Basics section for more information on cells and the problem geometry See the Files section for more information on the listing file For most examples the default thinning out should be used As a general rule you will get better accuracy for a given amount of time and memory when you use thinning Thinning out helps by removing currents which have little or no effect This reduces the number
368. used to your advantage to temporarily or permanently remove metal or components from the EMPOWER simulation Default Viahole Layers The Start Layer and End Layer combo boxes control the default layers for the viaholes These can be overridden individually for each viahole The grid in EMPOWER is a truly three dimensional grid rectangular lattice Z Directed currents and ports are mapped from the intersection points to the top or bottom cover There are two caveats metal and ports in the z direction are modeled as one continuous current so the viaholes should be small in comparison with a wavelength Also you cannot have both a port and metal along the same grid line so you should be extremely careful when placing a viahole directly underneath an internal port You should check the listing file select Show Listing File from the EMPOWER simulation right click menu carefully to see that both the port and the viahole are represented on the grid The physical length of a viahole in a substrate should be kept shorter than about 1 10 to 1 20 wavelength within the analysis range Longer lengths can suffer calculation inaccuracies in EMPOWER For example suppose a microstrip circuit with a 10 mil substrate and a dielectric constant of 2 4 is to be used What is the highest accurate frequency for this setup Note If the substrate layer is broken down into two substrate layers by adding an additional layer each 1 2 the height of the orig
369. variety of methods and parameters are available to control the approach that HARBEC uses to find convergence The speed of performance can be improved by adapting these parameters to the specific circuit being analyzed To understand how these parameters work it is useful to understand a little about how the simulator searches To find a solution the simulator uses a Newton Raphson search to find the solution It starts with an initial guess and calculates an error function The derivative of the error function is used to extrapolate the next point In harmonic balance partial derivatives exist for every node and every frequency The full matrix of partial derivatives is known as a Jacobian Jacobian Calculation The full Jacobian is usually the most accurate way to determine the next point However the matrix can be very large requiring a lot of time to calculate and invert To make the simulator faster HARBEC generally tries Fast Newton steps first A Fast Newton step calculates only a portion of the Jacobian and uses it to calculate the next point For many circuits the entire solution can be found quickly using only Fast Newton steps The default setting for HARBEC is to automatically switch between using Fast Newton and full Jacobian steps Artificial intelligence techniques are used to determine which technique to use and when Usually the automatic switching will find the solution quickly However for certain circuits it will be bett
370. wer measurement at the path input and the Cascaded Gain measurement at stage n as shown by CNF n CNP n CNP 0 CGAIN n dB where n stage number 173 Simulation 174 Note See the Channel Noise Power and Cascaded Gain measurements to determine which types of signals are included or ignored in this measurement Values Real value numeric Simulations SPECTRASYS Default Format Table Linear Graph Linear Smith Chart none Commonly Used Operatots Operator Description Result Type DB CNF cascaded noise figure in dB Real MAG CNF numeric value of the cascaded noise figure Real Examples Measurement Result in graph Smith chart Result on table optimization or yield DB CNF DB CNF DB CNF MAG CNF MAG CNF MAG CNF Not available on Smith Chart Since each spectrum can contain a large number of spectral components and frequencies SPECTRASYS must be able to determine the area of the spectrum to integrate for various measurements This integration area is defined by a Channel Frequency and a Channel Measurement Bandwidth which become the main channel for the specified path SPECTRASYS can automatically identify the desired Channel Frequency in an unambiguous case where only one frequency is on the from node of the designated path An error will appear if more than one frequency is available For this particular case the user must specify the intended frequency for this path in the
371. what types of signals will create intermods and harmonics See the Calculate Intermods Harmonics section for more information Harmonics 2nd and 3rd order harmonics will be created by the non linear elements when this option is selected Calculation time for harmonics is typically very quick Intermods 2nd and 3rd order intermods will be created by the non linear elements when this option is selected The 3rd order products include intermods due to 3rd order combinations of 3 or more signals Created From Sources Only When this option is selected harmonics and intermods will be create from source signals that initiated at a port All undesired products created along the path will be excluded from the calculation of harmonics and intermods All Signals When this option is selected harmonics and intermods will be create from all signals appearing at the input to the non linear element This option typically requires longer simulation time since more spectral components are being created For long simulation times see the System Simulation Tips section Maximum Mixer Order This option is used in conjunction with the Mixer Table element and will limit the order of the spectrums created at the mixer output to this value regardless of higher orders specified in the intermod table data 59 Simulation Calculate Noise When checked SPECTRASYS will calculate noise The option must be enabled for SPECTRASYS measureme
372. wn in the measurement wizard To bring up the measurement wizard select measurement wizard from the graph properties dialog box Measurement Result in graph Smith chart Result on table optimization or yield 22 dB Magnitude of 22 dB Magnitude plus angle of 22 QL S21 Loaded Q of S21 Loaded Q of S21 MAGJS21 Linear Magnitude of S21 Linear Magnitude of S21 IM Zin1 Input reactance at port 1 On a Smith Input reactance at port 1 chart S11 will be displayed while IM Zin1 will be used for the marker readouts S Shows dB Magnitude plus angle of all S Parameters RECTITS Shows real imaginaty parts of all S Parameters SB1 On Smith or polar chart shows input Displays center radius and stability plane stability circles parameter of input plane stability circles NCI On Smith or polar chart shows Displays center and radius of all noise circles constant noise circles 27 numbers per frequency In all dialog boxes which allow entry of measurements there is a Default Simulation Data or Equations combo box Any measurement can override this default The format to override the network is simulation design operator measurement whete simulation is the name of the Simulation Data from the Workspace Window design is the name of the design to use and operator measurement are as described in previous sections An override is most useful for putting parameters from different networks on the same graph Additionally the w
373. x Jy or Jz The solution or response function is a discrete function in the xy plane and continuous inside layer along the z axis Actually to solve the formulated problem we need just a contraction of the GGF to the signal plane and to the regions with non zero z directed currents This contraction is a matrix due to the discretization 293 Simulation 294 To find the GGF matrix we used a spectral approach similar to one used in the spectral domain technique or in the method of moments Nikol sku 1982 Vesnin 1985 Jansen 1985 Rautio Harrington 1987 Dunleavy Katehi 1988 Instead of continuous TE and TM rectangular waveguide eigenwaves Samarsku Tikhonov 1948 their grid analogues ate used as a basis to expand the electromagnetic field inside a layer The number of the grid TE and TM waves is finite and their system is complete This means that instead of a summation of series as in the spectral domain approach we have finite sums Moreover each basis grid eigenwave has a grid correction that provides convergence of sums to the series obtained by the continuous spectral domain approach Note that a backward process is impossible and a simple truncation of the series does not give the same answer as the grid technique The finite sums and the grid corrections are the most important things for monotonic convergence of the algorithm To construct the GGF matrix in the grid spectral domain the impedance form of the solution for a layer w
374. xactly the same on both pieces connected through the MMTLP The figure below shows an incorrect numbering of the spiral inductor In this example PART1 and PART2 are inconsistently numbered since on PART1 the outermost inputs numbers 2 and 6 are the lowest number while in PART2 the innermost inputs numbers 1 and 5 are the lowest number 257 Simulation e Pieces can be connected directly together without using MMTLP In this case the lowest ports in each modally related set of inputs are connected to each other 258 EMPOWER Lumped Elements and Internal Ports As described in the External Ports section every EMPOWER circuit must contain at least one port This section will cover lumped elements and internal ports ports inside the box External ports along a sidewall were also covered in that section The process of placing an internal port is similar to the process of placing an external port To summarize An internal port is placed in LAYOUT by selecting EMPort from the toolbar Internal ports can be placed anywhere in the box When the EMPort Properties dialog box appears first select Internal in the Port Type combo box Next fill in the width and length of the pad Press OK to complete the placement Note The rest of the options in the EMPort Properties dialog box were covered in the section entitled Port Options You may want to review these options now The figure below shows a comparison between port
375. xample is Filters Tuned Bandpass wsp This example demonstrates the following topics e Creating a layout from an existing schematic e Tuning with EMPOWER data e Using lumped elements with EMPOWER This circuit is a tunable bandpass filter Operational theory is given in the example above In GENESYS select Open Example from the File menu Then select Tuned Bandpass wsp from the Filters directory Double Click F2000 under Designs in the Workspace Window to display the schematic for this filter shown below 211 Simulation 212 52000 pF att This is the schematic of a 2nd order microstrip combline bandpass filter with 50 W terminations and transformer coupling on the input and output The lumped capacitors are gane tuned to adjust the resonant frequency of the two center lines Tuning in this manner affects only the center frequency and keeps the passband bandwidth constant G2000 pF Double Click Layout1 under Designs in the Workspace Window to display the layout for this schematic The layout for this example is shown below EMPOWER Operation A 0402 Chip Capacitor footprint has been used for each of the lumped capacitors Whenever a lumped element is used for an EMPOWER run GENESYS creates an internal ports for the element These ports ate placed e If Use Planar Ports for two port elements is checked in the EMPOWER properties box one port is created for 2 terminal elements like resistors or capacito
376. xtension of the method of lines for planar 3D structures Proceedings of the 15th Annual Review of Progress in Applied Computational Electromagnetics Monterey CA 1999 p 116 121 E G Farr C H Chan R Mittra IEEE Trans v MI T 34 1986 N 2 p 307 G Gronau I Wolff A simple broad band device de embedding method using an automatic network analyzer with time domain option IEEE Trans v MTT 37 1989 N 3 pp 479 483 D J Swanson Grounding microstrip lines with via holes IEEE Trans v MTT 40 1992 p 1719 1721 J C Rautio An ultra high precision benchmark for validation of planar electromagnetic analysis IEEE Trans v MTT 42 1994 N 11 p 2046 2050 T Kawai I Ohta Planar circuit type 3 dB quadrature hybrids IEEE Trans v MTT 42 1994 N 12 p 2462 2467 Y Gao I Wolff Miniature electric near field probes for measuring 3 D fields in planar microwave circuits IEEE Trans v MTT 46 1998 N 7 p 907 913 Index Avalable cant CU CLES ses minien an 141 2 AN 141 B B134 141 3 Back annotation A A eosin 41 31 D EEEE IA N E E EE ET 101 E E E ett meee 41 Balanced amphi DetS enean adiccoiao 122 A BND eg det eaten atte iia acetate at biel 103 A scans 217 VA s 0 1 Gi erence ea nie ES E L rn tre reer 32 Batch RUNS cecccccccccccccccccccccccccccccecececcccccccscccecceeees 231 PAT O 107 o attains E chores 138 139 ADSOLUtE Erro incaico 43 BESSEL cata 107 Absolute Tol
377. y This technique is also known as the impedance interpretation of boundary condition superimposition The GGF matrix obtained in the previous section can be represented as an impedance matrix Z of a multiport shown on the left below ZI Aen p PE TO DD A E ideal LEBER LS A RAI metallization AFA RAE ZAR a 7 DY La 4 200 A MBE E A dy 42 di ET A wee ce G3 Lmpedance y Ar ae Y Sr The multiport terminals are conceptual and their positions are just a schematic representation Four conceptual ports or pairs of terminals correspond to a grid cell as shown in the figure The total number of ports oriented along the x axis is M L 1 The total number of ports oriented along the y axis is L M 1 The multiport can also have a set of z directed ports corresponding to via holes or z directed internal inputs Note that we do not need to calculate all elements of the multiport impedance matrix and its order can be reduced taking into account that some ports are no loaded or short circuited The no loaded terminals correspond to regions of the signal layer without any conductivity currents The right half of the figure illustrates the correlation of other types of the boundary conditions to operations with the informational multiport terminals Operations with the z directed terminals are similar The operations in a discrete space of the informational multiport terminals are completely in accordance with the usual electroma
378. y and amplitude calculated from above Initial Frequency linearized calculation for the HarBEC simulation Edit Oscillator Port Manually edit the frequency and amplitude of the oscillator pott Display Spectrum and Waveform Graphs Have the HarBEC simulation produce a frequency domain and time domain representation of the output signal HARBEC Popup Menu 50 By right clicking on the HARBEC simulation icon on the workspace window the following menu appears TE GENESYS 7 5 Simple Detector Workspace Simple Detector File Edit View Schematic Synthesis Window Help m laj x PA EA eA EEL EZA Pr rt LRA Lumped Linear Nonlinear T Line Coax Microstrip Slabline Stripline Wave Mala Z x ae r Eq Designs Models wet Simple Detector Layout Layout A E Simulations D ata DCI TNE Rename Delete This Simulation D ata Workspace Actions Tools Vder YDC 0 138 Y Cblock C 1000 pF Port 1 p F 1000 MHz 1 PAC 20dBm o Adet R 500 ohm C 2100pF Recalculate now Mark results up to date Automatically Calculate v Active for Opt Yield Write all internal files Delete internal simulation data E aa Properties Show HarBEC Monitor Window 7 GAGA CACA MA MA kes es 2 Rename Allows the name of the icon to be changed Delete This Simulation Data Removes the icon and all of its associated data from the system
379. y available if Port Type is set to Normal see below On most complete circuits this value can be left at zero A positive Reference Plane shift causes the deembedding to add extra line length to the circuit A negative value is more common and causes the reference planes to move inside the box See the Patch Antenna Impedance example for an example of a patch antenna simulation and the Edge Coupled Filter example which uses a reference plane shift The reference plane is shown as an arrow on the layout Additionally when the EMPort is selected Handles appear on the reference plane allowing it to be moved with the mouse Port Number When EMPOWER is run the port numbers specified here correspond to the port numbers in the resulting data These port numbers must be sequential numbers cannot be skipped and Normal ports must always have lower numbers than non deembedded and internal ports LAYOUT assigns a new port number automatically when an EMPort is placed and the port number is displayed on the layout at the port Width amp Length When placing an external port on the end of a strip type transmission line you should normally leave these at zero so that LAYOUT sizes the port automatically If you want to override the size or for slot type or internal ports you can specify width and length here Note Width and length are measured relative to the line direction so these parameters can appear to be reversed Length is the
380. y circle is a locus of load impedances for which the input reflection coefficient S11 is unity This locus is plotted on a Smith chart and is only available for 2 port networks This locus is a circle with radius Rout about a point Cout where Rout S12821 S221 D Cout S22 DS11 1S21 D The region inside or outside the circle may be the stable region The filled areas of the graphs are the unstable regions The input plane stability circle equations are the same as the output plane equations with 1 and 2 in the subscripts interchanged Note See the section on S Parameters for a detailed discussion of stability analysis Values Complex values versus frequency Measurements Linear Simulations Linear Default Format Table center MAG ANGJ radius Linear Graph none Smith Chart Circle Commonly Used Operators None Examples Measurement Result in graph Smith chart Result on table optimization or yield SB1 input stability circle center MAG ANGI radius Linear par SB2 output stability circle center MAG ANGI radius Linear par Available on Smith Chart and Table only Parameter indicating the unstable region The Optimal Gamma for Noise is a real function of frequency and is available for 2 port networks only The optimal gamma is defined in terms of the reference admittance Yo and the optimal value of admittance Yopr as GOPT Yo Yorr Yo Yo
381. y circuits have data of interest in both the time and frequency domains which could warrant the use of both simulators For example an oscillator has phase noise transmission and phase characteristics which are all frequency domain measurements Oscillators also have waveform magnitude starting time and startup transients which are all time domain measurements In this case both simulators can be used in the circuit design There are some guidelines for deciding between SPICE and linear simulation Simulation Does the circuit depend on time domain characteristics If so SPICE must be used for this portion of the design If the circuit depends entirely on the time domain SPICE can be used exclusively However if a frequency domain response is also of interest linear simulation may be used in addition to SPICE What is the highest frequency of concern in the circuit If it s over about 100 MHz you may want to use linear simulation This is because component unloaded Q becomes a concern above this frequency and SPICE does not have the built in ability to include this effect in simulations If the frequency is much higher than this linear simulation is almost a must since SPICE uses lumped element models for RF parts which do not usually model high frequency effects accurately Is the circuit all lumped elements If so SPICE may be used However unloaded Q is not built into SPICE so guideline 2 must be considered Does the c
382. y consist of an arbitrary number of isotropic homogeneous dielectric or magnetic layers as shown below The electric E and magnetic H field vectors are related by Maxwell s system of equations EMPOWER Theory rot H ioe E Jz rot E iou H divE 0 divH 0 x y z EQ A 1 Here Jz is the volume density vector of z directed currents inside a media layer ep and mu are permittivity and permeability of the media layer ep is a complex value for a lossy media The z directed currents are constant values inside a layer but they can change from layer to layer which gives a possibility to discretize the problem along the z axis Thus we have all six components of the electric and magnetic fields inside a layer with constant current across it X and y current components can exist only in a signal layer z dj parallel to medium layer interfaces Generalized boundary conditions for the signal layer are 1 H dj H dj n 1 fE dj Edy 0 The signal layer plane can contain arbitrarily shaped regions of perfect metalization regions with complex surface impedances lossy metal resistive films and regions modeling lumped element connections All regions have zero thickness The top and bottom walls of the box can be ideal electric amp magnetic walls or walls with surface impedance The structure can also be terminated by semi infinite rectangular waveguides in the planes of the box top and bottom walls A clarifica
383. y of which are described in a book by Philip Smith 37 The Smith chart as displayed by GENESYS is shown in below Labels for normalized real and reactive components are added 39 Simulation 40 The design of broadband transmission systems using the Smith chart involves graphic constructions on the chart repeated for selected frequencies throughout the range of interest Although the process was a vast improvement over the use of a slide rule it is tedious Modern interactive computer programs with high speed tuning and optimization procedures are much more efficient However the Smith chart remains an important tool for instructional use and as a display overlay for computer generated data The Smith chart provides remarkable insight into transmission system behavior The standard unity radius impedance Smith chart maps all positive resistances with any reactance from to onto a circular chart The magnitude of the linear form of S11 or S22 is the length of a vector from the center of the chart with 0 length being a perfect match to the reference impedance and 1 being total reflection at the circumference of the chart The underlying grids of the Smith chart are circles of a given resistance and arcs of impedance The reflection coefficient radius of the standard Smith chart is unity Compressed Smith charts with a radius greater than 1 and expanded charts with a radius less than 1 are available High impedances are located o
384. zations G Yield po Parameters Enter E Notes Parms All Parts Shift Enter Schematic Properties Keep Connected Show Part Text lecent Patt n RET ft art efit Part D w T w maj w D w maj w 2 w aa w A d f A E T 1 2 4 Once the user is satisfied with the synthesis results these results can be substituted back into the behavioral model If a behavioral model have been directly synthesized the subnetwork substitution will be automatic as show below Part Properties For BPF_BUTTER x Parameters Simulation Simulation Parameter Override Use Parameters and Model as Entered C Disable Part for All Simulations Open Circuit Disable Part for All Simulations Short Circuit ALL terminals together Use fi y Port Datafile Browse At this point the parameters for the behavioral model will be disabled For additional information on model substitution see the Simulation Tab section of the Schematic Element Properties page in the User s Guide 97 Simulation 98 The basic operation of SPECTRASYS involves the propagation of individual source spectra and all of their derived products intermods harmonics etc to every node in the system These spectrums will keep propagating until no additional spectrums are created For instance any new inputs arriving at the input of an amplifier will cause intermods and harmonics to be created at the amplifier output at that particular

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