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User's Manual of QW-3D

1. i ra a a Ps ws B dU 85 73 d 17 489 2Z 0 QW View IN AIR View Draw Edit Setup Info Help t fe dU 531 d 6 Fig E 2 1 9 1 Example of the main window of QW Editor with a QW V2D project Here are some remarks concerning application of QW Editor in QW V2D projects basically most features and commands described for QW 3D in x y z coordinates are valid here for x p coordinates respectively QW Editor v 6 5 19 QWED PL Chapter E 2 Graphical editor the single layer of QW V2D structure must be placed at the level of 0 and have a height if a structure of different level or height is defined it will be truncated to the levels from 0 to in x p plane the structure cannot extend below the axis p cannot be negative E 2 2 The 2D windows Each of the 2D windows describes a chosen section of the 3D structure In the case of Fig E 2 1 8 1 the lower left one describes a section in XZ plane along the waveguide The upper left window describes a section in the XY plane We will concentrate here on this window because according to the remarks of Section UG 2 1 the XY plane is a natural base for investigating introducing and correcting the elements of which the project is composed It should be noted that when a 2D window describes the considered structure in XZ or YZ plane some of the commands of the Draw and Edit groups are blocked Thus in practical operation of the softwar
2. lt gt gt gt lt lt logical conditions parenthesis instruction delimiter arguments separator substitution amp amp logical and Il logical or string concatenation Math functions sin cos tan asin acos atan atan2 trigonometric functions and their inverses Attention arguments of trigonometric functions and results of their inverses are degrees log logd exp sqrt abs sgn int frac rand srand mathematical functions QW Editor v 6 5 81 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language Other commands and functions OPENF lt file name gt Close the file previously open if any and open a disk text file for reading Default file location is in the project directory READF Function returning the value of the next number read from the file defined by OPENF command READS Function returning the next string read from the file defined by OPENF command VAR lt text_expression gt It is a function which returns value of variable given as text expression STR lt arithmetic expression gt It is a function converting arithmetic expression a number into string CODE lt string gt lt n gt A function returning ASCII code of n th char in string or 1 if n lt 0 or n gt string length STL lt x1 gt lt yl gt lt zl gt lt x2 gt lt y2 gt lt z2 gt A command drawing STL format section Additional remarks Note that string concatenation a
3. E 2 5 3 Media parameters The command Parameters Media opens the dialogue window presented in Fig E 2 5 3 1 Each of the projects has its own list of media The list of the current project media is displayed on the right hand side of the dialogue window On the left hand side we have one of media libraries in which we store the parameters of media for all our projects These libraries are saved on the disk We can pick one of them the default one is called default m b which becomes a so called active library Note that a standard installation of QVV 3D contains three media libraries standard mlb standard_with_food mlb and default mib At the beginning default mib is a copy of standard_with_food mlb if you are not going to analyse foods please copy standard m b under the name Qefault mib Edit media library lt INSTALLDIR gt media default mlb Library medium Name Type i teflon Dielectric isotropic He Dispersion model metal alr open Electromagnetic parameters Eps Mu Sigma Sigmatel Thermal parameters Specitic heat Density Initial temp Thermal conductivity m fo a a Z fo Def colours Library file Help New Load Save e Exit Fig E 2 5 3 1 Parameters Media dialogue window The name of the active library appears in the header of the window One medium from this library is selected Its name and parameters are displayed in the central and left part of the dialogue window
4. The same as MESHXINDEX but in Y direction e MESHY lt n gt The same as MESHX but in Y direction e CREATEMESH Forces mesh creation inside UDO file Additional comments The MESHPAR command mimics the Setup Mesh command of QW Editor see Section E 2 2 1 and allows a global mesh settings The mesh can be locally modified with the PORTPAR command described in Section E 3 6 E 3 10 Files used by UDO language and their location In this Section we shall summarise general principles for locating the various files used in the UDO language and explain how the UDO interpreter searches for these files QW Editor v 6 5 96 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language udo files read from QW Editor When we want to invoke a new UDO object from QW Editor via the Draw Get Libltem command the contents of the recently used object library appear in the dialogue We can change the directory and pick up the desired udo file from any location When we want to modify an existing object and double click it on the Select Object list the name of the udo file describing this object is taken from the project In typical operation of the software full paths to all the used udo files are recorded in the pro file and hence we can be sure that the correct udo file will be loaded The only case of object modification which is not typical occurs if we have previously changed the recorded path to udo
5. e PML Such a port is used and works like absorbing wall but in this case the absorbing boundary condition is Perfectly Matched Layer e Lumped impedance option indicates a place where a lumped impedance is inserted across one FDTD cell The choice of the type of that impedance and its numerical parameters are explained in Section E 2 5 1 3 Note that e The user can mark several I O ports as sources In this case o Ifno S parameter postprocessing is chosen all these ports will be simultaneously excited with waveforms assigned to them in the I O Ports Parameters dialogue In particular the waveforms may have different amplitude and delay values o If Smn postprocessing is chosen each port will serve as a source in a different simulation with other ones serving as loads o If Sk1 postprocessing is chosen all ports will act with waveforms assigned to them and port No 1 will be treated as a reference port The results of such a postprocessing will be inconsistent with standard understanding of S matrices but may be useful in some unusual studies e The sources and reference planes are marked by arrows corresponding to the anticipated direction of the energy flow see Fig E 2 4 1 2 The absorbing ports are marked by triangles with vertices towards the direction from which the wave is coming imitating unechoic chamber walls The orientation of the I O ports and reference planes is important After drawing them please verify if the o
6. maximum cell size in Z direction lt arg4 gt lower limit of the meshed zone in X direction lt arg5 gt upper limit of the meshed zone in X direction lt argo gt lower limit of the meshed zone in Y direction lt arg gt upper limit of the meshed zone in Y direction lt arg8 gt lower limit of the meshed zone in Z direction lt arg9 gt upper limit of the meshed zone in Z direction lt arg10 gt 0 or 1 value 1 corresponds to checked Adjust to objects box in Mesh Parameters dialogue it causes that the whole circuit will be meshed and the above parameters lt arg4 gt lt arg9 gt will be ignored value 0 causes that the mesh will be restricted to the region defined by the above parameters lt arg4 gt lt arg9 gt e GETMESHPAR lt n gt A function returning the n th mesh parameter Argument n has to be in range 1 10 see MESHPAR command description how mesh parameters are enumerated e MESHXINDEX lt level gt A function returning The ordinal number of the border between FD TD cells situated most closely at or below in X direction from level if there is an FD TD mesh at or below level 1 if there is an FD TD mesh but situated above level 2 if there is no FD TD mesh e MESHX lt n gt A function returning the x coordinate of the n th mesh line border between FD TD cells The mesh lines are counted up in X direction with the leftmost one numbered 0 e MESHYINDEX lt level gt
7. 0 or 1 if 1 lt size gt is active lt port_plane gt 0 or 1 if 1 mesh is snapped to the port plane lt port_circumf gt 0 or 1 if 1 mesh is snapped to the port circumference e PORTPAR2 lt subcircuits_margin gt lt active_walls gt lt dummy gt lt dummy gt Sets subcircuits_margin property of the port similarly as the Advanced features dialogue called from the I O ports dialogue lt subcircuits_margin gt adjacent subcircuits overlay number of common cells lt active_walls gt 3DP PLANEWAVE active walls coded on bits 32 X 16 X 8 Y 4 Y 2 Z 1 Z parameter ignored for 1 lt dummy gt parameter for future usage value 1 recommended e GETIOPAR lt file_name iop gt The I O port parameters are read from the file file_name iop For principles of the op file location please refer to Section E 3 10 e PORTEXC lt pointlz gt lt point2z gt Allows to move the excitation points to arbitrary z level It is needed to use special excitation point arrangement for template calculation in vertical ports e PORTPOSTP lt argl gt lt arg2 gt Refers to lumped source probe and determines in which postprocessing it is to be included analogous to FD probing and S as port No check boxes in the I O ports dialogue of QW Editor lt arg1 gt 0 or 1 if 1 the lumped source probe is included in FD probing lt arg2 gt 0 or 1 if 1 the lumped source probe is included in S parameter extraction e EPSE
8. DOWN do actref UP endif endif refpos ptr if pdir DOWN do refpos ptr endif portkind INPTEMPLATE if kind 2 do portkind OUTTEMPLATE endif PORT z hpo portkind pdir pname r pname NEWLINE x y x ytwip NEWLINE x yt y1 x yt y1 if pio NO do GETIOPAR pio iop endif ENDPORT PORT z hpo REFERENCE actref r pname pname NEWLINE x refpos y x refpos y wip NEWLINE x refpos yt y1 x refpos yt y1 ENDPORT CLOSEOB J Postprocessing and circuit parameters FDPROB lt lower_freq gt lt upper_freq gt lt freq_step gt Enables frequency domain probing FDPROBPAV lt lower_freq gt lt upper_freq gt lt freq_step gt Enables frequency domain probing for power available from the source SKIDIFF lt lower_freq gt lt upper_freq gt lt freq_step gt lt assumptions gt Activates SKI differential postprocesing S correction assumptions options 0 nonreciprocal N port 1 reciprocal N port 2 reciprocal lossless 2 port SMNDIFF lt lower_freq gt lt upper_freq gt lt freq_step gt lt assumptions gt lt mode gt lt IterForS gt Activates Smn differential postprocesing S correction assumptions options 0 nonreciprocal N port 1 reciprocal N port 2 reciprocal lossless 2 port mode options 0 single simulator amp single thread 1 multisimulator 2 multithread NTF lt frequencies_string gt Enables NTF postprocessing NTFBKG lt eps gt lt mu gt
9. QW Editor Reference Guide QuickWave is a general purpose electromagnetic simulator based on conformal finite difference time domain method version 65 Copyright QWED Warsaw 2007 Table of Contents E 1 FUNDAMENTALS OF THE METHOD OF ANALYSIS E 2 GRAPHICAL EDITOR E 2 1 Main menu and submenus of QW Editor E2Ae E 2 1 2 File group of commands Parameters group of commands E 2 1 2 1 AMIGO E213 E 2 1 4 E21 E 2 1 6 E217 E 2 1 8 E219 Windows group of commands Project group of commands Tools group of commands Help group of commands Overview of icons within QW Editor main window Displays of the shape of QW 3D projects Displays of the shape of QW V2D projects E 2 2 The 2D windows E22 B22 E223 E 2 2 4 E22 E 2 2 0 E221 The Setup group of commands The Edit group of commands The Draw group of commands The View group of commands The Info and Help groups of commands Toolbar of 2D window Additional remarks on wire grids asymptotic boundary conditions E 2 3 The 3D windows E 2 4 Drawing and editing ports E 2 4 1 E 2 4 2 E 2 4 3 Drawing I O Ports and reference planes Drawing mesh snapping planes and symmetry planes Editing ports E 2 5 Parameters of wave simulation E 2 5 1 Input Output Port parameters E 2 5 1 1 I O Port Parameters in the case of transmission line ports E 2 5 1 2 I O Port parameters in the case of absorbing walls E 2 5 1 3 I O Port p
10. There are two types of absorbing boundary conditions ABC Mur with superabsorption and PML see Fig E 2 5 1 2 1 Here are some remarks about their application e In general the PML ABC is more accurate and its performance is less dependent on the angle of incidence However it has some disadvantages It is rather time and memory consuming It cannot be placed in a region of boundary conforming cells of shapes other than rectangular QW Editor v 6 5 55 QWED PL Chapter E 2 Graphical editor Practically it is stable only when its sides coincide with the grid termination or a metal wall Thus it is recommended mostly for antenna problems when we use the absorbing box surrounding the antenna or for a reflectionless termination of a rectangular waveguide e The user can choose the PML profile type parabolic or exponential and the thickness of the PML layer expressed in FDTD cells The application of those options is discussed in Section UG 2 3 3 e Mur ABC is more flexible It can be applied practically in any case and its implementation takes into account the conformal cells Thus it is a standard choice in the case of termination of arbitrarily shaped transmission lines As shown in various in the User Guide it can also be quite effective in antenna problems However since the Mur ABC assumes travelling wave conditions it should be placed at least half wavelength from the antenna to avoid intense interaction with antenna near fi
11. Perpendicular to XY plane is the only available Orientation and pressing Draw automatically creates the port along the selected line QW Editor v 6 5 29 QWED PL Chapter E 2 Graphical editor Edit Element This command serves to change the position and parameters of the elements When this command is invoked we should approach the element to be changed with the cursor and press the left mouse button We can move the element and set its new position by pressing the left button once more We can also press the right button to get into the Element Change dialogue corresponding to this particular element in which its parameters can be changed The Element Change dialogue for a simple element is shown in Fig E 2 2 2 5 the dialogues for ports are described in Section E 2 4 1 and for wires and wire grids in Section E 2 2 7 Most of the parameters are self explaining Let us only comment on some aspects of them Element Change x Name h3thrb_flare shift EscE cit Type Element E jo Height fi z o er Amiga status Disable f Soft Hard edges f Hard Mark Hy Grid Active Passive Bi phase Cancel Pik Fig E 2 2 2 5 Element Change dialogue window o Note that the medium can be defined inside or outside the element This means that after defining the shape of the element the QW Editor acts on the inside outside space and fills with the given medium all the ava
12. This number is crucial for judging if we have sufficient amount of memory to run this example with this meshing and how long the simulation will take Note that the user is strongly recommended to verify the actual settings of the mesh and special planes in the dialogue of Fig E 2 2 1 10 or in the dialogue of Amigo before running the simulation E 2 2 2 The Edit group of commands The Edit group has the following commands Undo command permits to revoke up to M moves in QW Editor Here are some remarks regarding the choice of N o Ncan be set by the user in zednqw ini file cf Section E 4 1 o The default value used in the installation of QW 3D is N 10 cf Section UG 1 4 or V2D 1 4 o Note that each remembered move of QW Editor must be stored in the operational memory Thus do not set high values of N when QW Editor and other applications are executed in parallel close to the memory limits of your computer QW Editor v 6 5 27 QWED PL Chapter E 2 Graphical editor o The undo record does not register all the actions of QW Editor Some actions were considered of less importance and not worth the time and memory expenditures However if you have a different opinion please do not hesitate to contact QWED with comments The undo command is a new feature and the users feedback will be valuable for its further enhancement QW Edit IN AIR E 0 x View Draw Edit Setup Info Help O H 9 unds cez B IEA G ajo Red
13. lt range gt lt new_name gt Changing the name of an element or an object lt item_type gt subject to operation ELEM element OBJECT object lt range gt range of operation name name of a single element or object to be marked LAST last created element or object lt new_name gt string representing the new name of the element or the object DELETE lt item_type gt lt range gt Deleting element s or object s lt item_type gt subject to operation ELEM elements ELEML local elements those created in the currently open object QW Editor v 6 5 92 QWED PL Chapter E 3 OBJECT objects Syntax of the User Defined Object UDO language OBJECTL local objects those created in the currently open object lt range gt range of operation name name of a single element or object to be marked ALL all elements or local elements or objects or local objects ALLACTIVE all active elements or local elements ALLPASSIVE all passive elements or local elements LAST last created element or object SETPEN lt colour_R gt lt colour_G gt lt colour_B gt lt width gt lt style gt Defines the pen colour line width and style for drawing the elements marked with the MARK command lt colour_R gt lt colour_G gt lt colour_B gt RGB parameters of the line colour lt width gt line width lt style gt line style 0 continuous 1 dashed 2 dotted comm
14. lt y1 gt lt x2 gt lt y2 gt Insert line from point x1 y1 to point x2 y2 ADDLINE lt x3 gt lt y3 gt Insert line from previous point to point x3 y3 ADDX lt dx gt Insert a line parallel to X axis from x2 y2 to x2 dx y2 ADDY lt dy gt Insert a line parallel to Y axis from x2 y2 to x2 y2 dy ADDXYZ lt x gt lt y gt lt z gt Insert a contour point to be used only in the group of library contour objects CLOSELINE Insert line from previous point to x1 y1 point of the last NEWLINE INSERTMEDIUM lt mediumname gt lt type gt Inserts a new medium into the project if medium of the same name does not exist The parameter type options are ISOTROPIC ANISOTROPIC DIELECTRIC_DISPERSIVE FERRITE METAL PEC PMC MEDIUMPAR lt mediumname gt lt epsx gt lt mux gt lt sigx gt lt msigx gt lt epsy gt lt muy gt lt sigy gt lt msigy gt lt epsz gt lt muz gt lt sigz gt lt msigz gt lt density gt Change the parameters of the medium mediumname to those specified by the subsequent parameters These parameters should be self explaining by comparison with those displayed in the Parameters Media dialogue window Note that the above instruction will not change the type of the medium Thus for example if the considered medium was declared in the Parameters Media dialogue or in INSERTMEDIUM command as isotropic the values of epsy epsz muy muz etc declared as a
15. 17 File Export 17 File Export Options 17 File Export amp Run 17 File Export amp Test 17 File Export Run amp Start 17 File Export Run amp Start Prony 17 File Load 17 File New 17 File Save 17 File Save as 17 File UDOPath 17 Fill for Image 43 Free Rotation 43 from X 43 from Y 43 from Z 43 from X 43 from Y 43 from Z 43 Help About 17 Help Contents 17 Hide Ports amp Boxes 43 HV Grid 32 Info Mesh 39 Initial View 43 QW Editor v 6 5 107 Lights 43 Parameters Amigo 17 Parameters Circuit type 17 Parameters I O Ports 17 Parameters Media 17 Parameters Units 17 Project Draft Modify All 17 Project Final Modify All 17 Setup Axes 39 Setup Circuit type 39 Setup Grid Snap 39 Setup Level 39 Setup Mesh 39 Setup Plane 39 T 105 Tools ACIS Viewer 17 Tools Calculator 17 Tools DXF Converter 17 Tools SAT Filter 17 Tools Simulator 17 Tools UDO Editorr 17 Translate 43 Undo 43 Up Down Zoom 43 View Elements 43 View Extens 39 View Options 39 View Zoom 39 Windows Arrange 17 Windows Open ProjectInfo 17 Windows Open 2D 17 Windows Open 3D 17 Windows Refresh 17 X Rotation 43 Y Rotation 43 Z Rotation 43 cell size 5 25 26 27 38 circuit type 8 21 22 commands 7 Activity 50 Arrange 13 Axes 23 Brush 68 Circle 35 Circuit type 21 Clear 37 Close 36 Combined Element 35 Coordinates 24 Del 68 Displacement 43 Draw Get LibItem 40 68 97 Draw
16. 2 internally by QW Editor QW Simulator operates internally in millimetres Thus as explained in Section S 2 7 1 QW Simulator will display the values of electric and magnetic field in V mm or A mm respectively Conversion from the user selected units into millimetres is performed by QW Editor at export of shape files sh3 cf Section S 4 3 2 In principle the choice of units is arbitrary but in certain specific applications a limited dynamic range of QW Editor s operations should be taken into account e You can write very long numbers into the QW Editor s dialogues However all resultant coordinates describing all created or modified elements lines points ports etc will be instantaneously snapped by QW Editor to 5 digits after decimal point i e 10 in current units e In project files pro saved by QW Editor upon the File Save command all coordinates are written with the accuracy as above e In shape files sh3 saved by QW Editor upon the File Export command all coordinates are written with the accuracy of 15 significant digits in millimetres always in exponential form if necessary The above limitations should not restrict flexibility of applying the software or its overall accuracy as long as you proceed in a reasonable way and do not try to define a circuit that is really one micron thick at the level of one thousand inches As a safe guideline we recommend such choice of the units that th
17. 25 38 45 47 FDTD iterations 62 FDTD mesh 22 25 45 47 49 50 FDTD method 5 FDTD simulation 33 50 59 61 70 field distribution 5 6 55 59 File group of commands 7 files bmp 97 105 i0p 87 98 105 mlb 105 pa3 70 105 pro 7 69 97 105 sh3 69 70 71 105 106 ta3 105 txt 72 98 udo 72 73 75 85 90 97 98 105 files bmp nobitmap bmp 74 files env zedglob env 105 files exe qed exe 104 files ini zednqw ini 14 27 104 files 10p file name iop 87 files mlb default mlb 63 105 standard mlb 63 standard with food mlb 63 files pa3 wetocx1 pa3 70 files pr1 project _name prl 105 files pr2 project _name pr2 105 files pro corhorn3 pro 19 emptyex pro 94 project_name pro 105 wetocxl pro 17 70 files sh3 wetocx sh3 70 files ta3 wetocx1 ta3 70 wetocx10 ta3 70 files txt points txt 82 83 project _name txt 105 files udo cxvld udo 74 75 portox udo 88 taper udo 83 84 threeel udo 76 77 82 tool udo 93 94 verstep udo 73 verstepa udo 73 74 wiregrid udo 40 Finite Difference Time Domain method 5 Fourier transform 5 46 59 60 Gaussian beam 57 Generalised Pencil of Function Method 62 QW Editor v 6 5 109 hard edges 12 hard planes 12 Help group of commands 16 H field 60 H field components 5 Info and Help groups of commands 38 Info group of commands 38 installation 27 73 104 keys E 28 30 K 28 34 45
18. 5 108 Set Plane 48 50 Setup Axes 25 Setup Level 28 34 36 Setup Mesh 38 72 96 Setup Plane 18 Shift 48 50 SPlanes boundaries 36 Switch 43 Tools ACIS Viewer 17 Tools Calculator 17 Tools DXF Converter 17 Tools SAT Filter 17 Tools SAT Viewer 44 Tools Simulator 17 Tools UDO Editor 17 Undo 27 34 104 Windows Arrange 17 Windows Open ProjectInfo 17 Windows Open 2D 17 Windows Open 3D 17 Windows Refresh 17 Wire 35 Zoom 37 43 Courant stability criterion 38 dialogue windows 2D view options 37 2D Axes Setting 24 AMIGO 10 Circuit 21 Coordinates Options 25 Define Level 23 Define Plane 22 Draw Object 84 Edit I O port 29 Edit special planes 48 Edit special boundary 50 Element change 32 Element Change 30 Export option 8 Grid Snap Parameters 24 I O ports 45 I O Ports Parameters 54 56 57 58 61 Join 34 Keyboard Entry 28 Mesh Splanes info 26 Object Change 31 Parameters Media 63 65 66 67 68 79 Plane shift rotation 23 Processing Postprocessing 59 61 Reproduce 34 Select element 31 33 34 Select object 33 Setup Mesh 25 Special planes and boundaries 49 View Elements 44 discretization 5 53 dispersion model Debye 65 Drude 65 Lorentz 65 Draw group of commands 34 dynamic template 54 efficiency 6 E field 60 E field components 5 41 60 examples 73 83 88 93 QWED PL Chapter E 5 Index corhorn3 pro 19 wetocxl pro 17 70 FDTD 5 FDTD cell
19. I OPorts 29 44 Draw SPlanes boundaries 26 38 49 Edit 35 Edit Element 30 Edit Line 29 Edit Object 30 Edit Point 28 Edit Port 28 Edit Element 32 Edit Join 32 QWED PL Chapter E 5 Index Edit Object 32 Edit Point 28 29 35 53 Edit Port 47 Edit Redo 34 Edit Reproduce 30 32 Edit Select Element 28 35 44 Edit Select Object 30 Edit Undo 34 Element 34 Elements 43 Exit 8 Export 7 Export Options 7 Export amp Run 7 Export amp Test 7 Export Run amp Start 7 Extents 37 File Exit 17 File Export 17 69 70 105 File Export Options 17 File Export amp Run 17 70 105 File Export amp Test 17 File Export Run amp Start 17 File Export Run amp Start Prony 17 File Load 17 File New 17 File Save 17 69 File Save as 17 37 File UDOPath 17 Get 36 88 Grid Snap 24 Help About 17 Help Contents 17 Help Info 38 Info Mesh 26 38 Insert 68 IOPorts 36 Join 34 Level 23 Load 68 Mesh 25 38 Modify 31 New 68 Next 36 68 NTF box 36 Object 36 Open 36 Options 37 Parameters Amigo 17 Parameters Circuit type 17 21 Parameters I O Ports 17 48 Parameters Media 17 63 Parameters Units 17 Pen 68 Plane 22 23 Plane wave box 36 Project Draft Modify All 17 Project Final Modify All 17 Put 88 Rectangle 34 Redo 28 34 Refresh 13 Reproduce 33 Save 43 68 Select Element 31 32 36 48 Select Object 32 QW Editor v 6
20. Ins anizo Dielectric anisotropic ai open Dispersion model Electromagnetic parameters Sigma Sigmar Library medium Name Type Project media metal lorenz gt Dielectric dispersive Ins air open Dispersion model Electromagnetic parameters Mu Signa Sigmahd i os Dispersion E Dispersion H eps_int no v_c GHz 5 p eps f t pIGHz f p fA Edit media library lt INSTALLDIR media default mlb Library medium Project media I Mame ppe eat dudeb x Meta material Ins air open Del Hert Dispersion model E Drude r H Debye r Electromagnetic parameters Sigma Sigmatel fo lo Dispersion E Dispersion H Ea eps_int ee vicolGHz 5 teGhahSs ooo Fig E 2 5 3 5 Parameters Media dialogue window for a Metamaterial QW Editor v 6 5 66 QWED PL Chapter E 2 Graphical editor Edit media library lt INSTALLDII KII Library medium Project media Mame Type ferrite Ferite zi us Dispersion model Electromagnetic parameters Sigma Sigma Eps Mu afaf00z2 H Ms foz m Hifi59155 pm Fig E 2 5 3 6 Parameters Media dialogue window for a Ferrite medium Note the following meaning of abbreviations used in the dialogue e Eps s dimensionless e Mu u dimensionless e Sigma o S m e SigmaM om 120 T1 muon 120 T1 Q m e Density p g cm e Specific heat J g C e I
21. PL Chapter E 2 Graphical editor VO ports Type Name Lumped source probe tempt Transmission line Absorbing wall PML Source Lumped impedance Fostprocessing Orientation FD probing Perpendicular to 1 plane 5 as port No Parallel to wr plane Advanced features Forced cell size Minus E Plus lo Snap mesh to W port plane JY pork circumference Parameters Pen Cancel Fig E 2 4 1 1 Dialogue windows for drawing I O ports On the left hand side of the window we must define the type of the port There are four exclusive possibilities Lumped source probe describes a port defined by its current and voltage at certain nodes In version 6 5 we can consider lumped ports only across one FDTD cell The point position will be fixed by a left mouse button click or by entering the coordinates from the keyboard after pressing K key Orientation is irrelevant The circuit model of the lumped port consists of a voltage source in series with a resistor It reduces to e aresistor if the source is desactivated e an ideal voltage source if resistance is set to zero e an ideal current source if resistance is set to INF Regarding sources note that they become electric voltage current sources if the port is connected to one of the electric field components and magnetic voltage current sources if the port is connected to one of the magnetic field compo
22. Postprocessing soie i EPRS 5 Parameters extraction ff SEI at reference planes l p I reciprocal N port SKI at ports E reciprocal lossless 2 port C Sion at reference planes f Sequential 5000 terations per port Multi simulator D Multithread Prony method I Apply Test every rood iteration below frooond NTF background Eps Mu Sigma Sigmaht SSS SSS SS ea ts Fig E 2 5 2 1 Processing Postprocessing dialogue box Analysis of embedding impedance for lumped elements Typically such an analysis would be performed for lumped elements placed between two metal elements wires plates or blocks These metal elements should be separated by one FDTD cell and a Lumped source probe should replace the lumped element Starting with version 5 0 a simpler option is also available the source can be placed directly on the wire without manually making a one cell gap and the software will cut the gap automatically provided that the Lumped source probe impedance is different than INF The Lumped source probe of INF impedance placed on the wire will not add any excitation or loading to the circuit only mark the point where current flowing in the wire will be calculated by H field loop integration In the I O Ports Parameters QW Editor v 6 5 59 QWED PL Chapter E 2 Graphical editor dialogue the Exciting field for this source should be selected as the E field component along the replaced element perpendicular t
23. To see the whole list of the active library media press the arrow box to the right of the name of the current medium From this list we can select any other medium to display its parameters These parameters can be modified QW Editor v 6 5 63 QWED PL Chapter E 2 Graphical editor Each non dispersive medium can have up to fifteen parameters Twelve of them describe its electromagnetic properties permittivity permeability conductivity and magnetic losses along the three main axes of the coordinate system Dispersive media have additional parameters describing the dispersion model There are also three thermal parameters Specific heat and initial temperature are relevant only if the QW 3D package operates with the optional QW BHM module Density is used in QW BHM and also for calculating Specific Absorption Rate SAR The following media types are supported by QW 3D e PEC is an abbreviation for perfect electric conductor In this case no parameters of the medium are needed e Metalic is a lossy metal Magnetic permeability Mu w dimensionless and electric conductivity Sigma o S m can be declared Note that although the meaning of these two parameters is exactly the same as in the case of media with volumetric losses declaring a particular medium as a metal with surface losses enforces an absolutely different approach to its modelling in the FDTD analysis Namely QW Simulator will not calculate the fields inside this metal v
24. UG 2 16 or V2D 2 4 with possible cross checking of the information provided there with information provided in this Section E 2 1 2 1 try to apply AMIGO in other standard examples described in Sections UG 2 2 to UG 2 15 or V2D 2 1 2 3 When the geometry of the structure to be analysed is introduced into QW Editor press EP Parameters Amigo to obtain the dialogue as shown in Fig E 2 1 2 1 1 AMIGO dialogue contains four groups of commands e Circuit group of commands is a copy of chosen commands accessible also by the path Setup Circuit type described in Section E 2 2 1 Thus it will not be described here e Frequency group allows setting the frequency band of interest The limits of frequency band f1 and f2 are to be defined in the upper line of that group If the checkbox of the line below is checked these frequency bounds f1 f2 will be copied to the Parameters I O Ports dialogue as the frequencies f1 and f2 of the Excitation waveform pulse of spectrum fl lt f lt f2 They will be also QW Editor v 6 5 9 QWED PL Chapter E 2 Graphical editor copied to the dialogue Parameters Postprocessing setting the bounds of the frequency range for all active S parameter and FD Probing postprocessings The frequency resolution df will be used to find the minimum number of FDTD iterations needed to obtain well converged results see FDTD iterations group of commands for more explanations The value of df 5 will be used as a frequency step
25. Windows Project Tools Help OEH 2 amp 7 wi fw Boui any H T QW Edit IN METAL View Draw Edit Setup Info Help View a fOr sO Ol wil a x 1O Oboe 2 feo ey o w E m seso et m x xy v7 z fae CD View Draw Edit Setup Info Help COOL LLL oii WEE G g 15 amp bce CeCe a E SREO ol fa ral Po PSS TTT TT TET T 1DODGOTHIAHADIOMeOe oo oo PCE TER ER ARERR AA E T E RSPAS RST T H ECT AT EE EEEE T ETT EEE ECET 1E me o ae ee bk C EEI oso E E E E a an E E E Coe COO PICT cases TO De Fig E 2 1 8 1 Example of the main window of QW Editor with a QW 3D project QW Editor v 6 5 18 QWED PL Chapter E 2 Graphical editor E 2 1 9 Displays of the shape of QW V2D projects Example of the main window with a QW V2D standard example corhorn corhorn3 pro is presented in Fig E 2 1 9 1 The list of commands and toolbars are basically the same as in QW 3D Here we will underline the specific features interpretations and restrictions concerning QW V2D projects As it was pointed out in the first chapter of QW V2D User Guide the QW V2D projects are considered in cylindrical coordinates x o with the assumption that the dependence of fields on the coordinate is analytically known Thus in fact we consider the structure in two dimensions x and p In terms of FDTD meshing we have just one layer of FDTD cells reproducing the shape of the structure in the plane x p see upp
26. are enforced by the user using Setup Mesh Mesh boundaries Attention side effect of EXPANDMESH command is immediate mesh creation e SETSUSPFLAGS lt draw_suspended gt lt skip_EXPANDMESH gt lt slicing phase gt Sets internal QW Editor flags Arguments are Boolean values lt draw_ suspended gt 0 or 1 if 1 the next elements will obtain suspended flag lt skip_EXPANDMESH gt 0 or 1 if 1 the EXPANDMESH command will be ignored lt slicing_phase gt 0 or 1 if 1 changes the phase of QW Editor to FINAL without modifying and redrawing project like button if 0 the QW Editor switches to DRAFT phase without modifying and redrawing project like button E 3 9 Controlling the mesh So far it has been explained how to set a mesh snapping plane and how to enforce a particular meshing UP or and DOWN from such a plane using PORTPAR command see Section E 3 6 There was also QW Editor v 6 5 95 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language a presentation in Section E 3 8 of the functions MESH and MESHINDEX which are very useful in generating biphased objects Here we will supplement these commands with some other commands which may be useful in controlling the meshing in all directions e MESHPAR Karg gt lt argl0 gt Enforces meshing in the whole circuit or in its part lt arg1 gt maximum cell size in X direction lt arg2 gt maximum cell size in Y direction lt arg3 gt
27. as a kind of dummy ports not performing the input output functions Thus they are declared in the udo file in the similar way as other ports and their type should be declared as SPECIAL For example to declare a mesh snapping plane for y d we may write QW Editor v 6 5 85 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language PORT z H SPECIAL NONE sp1 NULL NEWLINE x W y d x W ytd NEWLINE x y d x y d ENDPORT The parameters x z H and W influence presentation of the special plane in QW Editor They should not influence the electromagnetic analysis e So far we have considered how the geometry of the port can be defined in UDO It is also possible to specify some parameters of the port by including additional commands inside the port frame between the PORT and ENDPORT commands There are the following commands available PORTPAR PORTPAR2 GETIOPAR PORTEXC PORTPOSTP Syntax of port commands e PORT Klevel gt lt height gt lt type gt lt activity gt lt name gt lt reference gt Starts the port frame lt level gt level of port base lt height gt height of port lt type gt type of port corresponding port types of QW Editor shown in brackets POINT PROBE INPTEMPLATE OUTTEMPLATE MUR PML SHORT OPEN SPECIAL NEUTRAL BETWEEN CONNECT SUBCBASE REFERENCE NEAR2FAR PLANEWAVE CONTOUR_E CONTOUR_H FDMONITOR SUBGRID SUBREGBORD LUMPEDIMP Lumped source probe
28. cells Since the step in time of the FDTD analysis must be adjusted to the smallest cell Courant stability criterion existence of very small cells can drastically slow down the simulation process Thus small cells should be avoided whenever not absolutely necessary for correct space approximation of the analysed structure Since during the editing process the user can unintentionally introduce very small cells we recommend as a good habit consulting the list of mesh snapping planes any time after important changes in the structure have been made Note that the dialogue describing the special planes can also be reached from the Setup Mesh Splanes info path Some additional information has been given in Section E 2 2 1 e The Help Info command is not operational in version 6 5 E 2 2 6 Toolbar of 2D window e Kk EF ESE So BEL Fig E 2 2 6 1 The toolbar of a 2D window Most frequently used commands of the 2D window can be invoked using the toolbar icons The consecutive from left to right icons have the following meaning QW Editor v 6 5 38 QWED PL Chapter E 2 Graphical editor View Zoom ua Edit Object View Extens SE Edit Select Element E View Options 30 Edit Select Object Draw Element Rectangle PA Setup Circuit type Draw Element Circle polygon af Setup Plane te Draw IOPort F Setup Level Draw S Planes boundaries Setup Axes 2 Draw Get Libltem Setup Grid Snap x Draw Clear ath Setup Mesh cit Edit Undo Ct
29. components tangential to the metal surface To reproduce the frequency dependence we attach to each of the tangential magnetic field components an RL ladder composed of a finite number K of cells With the number K increasing we can model accurately the skin effect in a wider band but at the price of increasing computer time and memory That is why we allow the user to make a choice of the model to be used The three options Narrow Decade and Two Decades correspond to the number K varying from 2 to 12 with appropriate change in wide band properties of the model The central frequency for the band is taken as in the case of sinusoidal excitation frequency of the source in the case of pulse excitation central frequency of the band of postprocessing in the case of pulse excitation and no postprocessing 10 GHz e Plane Here we define the local 2D coordinate system There are two vectors U and V to be defined We use the general system XYZ of coordinates to define the common origin and the end of each of the vectors U and V describing the local system There are also shortcut keys to set the vectors U and V in the basic planes of the general system XY YZ and ZX 2 x xf ff p Cancel e Get Put Shit Ro E Fig E 2 2 1 3 Define Plane dialogue window QW Editor v 6 5 22 QWED PL Chapter E 2 Graphical editor Plane shift rotation Shift Rotation xE Fre ve z0 Fig E 2 2 1 4 Plane shift r
30. excitation during the template generation The other one is not relevant in most applications Both points are placed at the height of H 2 unless this is changed using PORTEXC command Let us now declare a similar port but in the XY instead of YZ plane PORT z 0 INPTEMPLATE UP input rinput NEWLINE x W y H 2 x W y H 2 ADDLINE x W y H 2 ADDLINE x W y H 2 CLOSELINE NEWLINE x y x y ENDPORT Here we have the port height equal zero and we must declare a rectangle in the plane XY It is done in the same way as in the case of introducing a rectangular base of an element As in the previous case we declare here an extra line which in fact is a declaration of two points the first one being the point of field excitation during the template generation In the above examples we have considered a port which is supposed to have a reference The reference should be declared as a separate port placed immediately after the corresponding I O port In the case of the first port considered in this Section its reference could be declared as follows PORT z H REFERENCE UP rinput input NEWLINE x W y d x W ytd NEWLINE x yt d x y d ENDPORT The reference was declared to appear at a distance d from the port Note that the second NEWLINE declaration appears here for the reason of uniformity of the port formats and does not contain relevant information It should be noted here that mesh snapping planes are treated by the software
31. group of commands QW Edit IN AIR a olk View Draw Edit Setup Info Help OQ Zoom log ts fm x Extents coy gt Oo Options Fig E 2 2 4 1 View group of commands of QW Edit menu The View group contains the following commands e Zoom activates a window zoom The cursor changes from i to and now allows marking a rectangular region to be shown occupying the window e Extents restores the full picture e Options opens 2D view options dialogue with four groups and five buttons gt 2D view options 2 x Aspect show Background colour f Isotropic Iv Mesh IN AIR Axes IN METAL F Linesin front Lines in plane P Lines behind ma Cancel f Normal Thick lines W Marked Active Passive Fig E 2 2 4 2 2D view options dialogue window o Aspect group allows selecting between isotropic display with natural vertical to horizontal proportions or fill display filling the entire window with proportions changing with the window proportions QW Editor v 6 5 37 QWED PL Chapter E 2 Graphical editor o Comb s edges allows choosing whether the edges of combined elements be displayed in Normal way as Pale lines or be hidden None The latter two options help obtaining a clear picture in projects constructed with many combined elements modelling geometry variation along the z axis o Show controls which lines are displayed in the window M
32. group of commands of QW Editor menu File group contains typical operations reading writing on files describing the structures to be analysed projects The projects are saved on a disk under the name chosen by the user with the extension pro Beside these commands the group contains also three Export commands Export means creating on a disk a set of files describing the project which are needed by the QW Simulator Export amp Run command not only performs the export but also opens the QW Simulator as a Windows application and loads project_name ta3 and other exported files into it The simulation can then be started by simply clicking over the green light in the QW Simulator Export amp Test performs the same actions as ExportGRun but loads project_name pa3 only and opens View TestMesh However since other exported files are not loaded this command cannot be followed by starting the simulation Export Run amp Start command performs all actions of Export Run and then automatically starts the simulation Export Run amp Start Prony command is available if Prony method is activated in the Processing Postprocessing dialogue It performs the same actions as Export Run amp Start but simulation is started on file project_name_prony ta3 The user can influence the Export process and thus the subsequent process of circuit analysis through the Export Options command see Fig E 2 1 1 2 In particular QW Editor v 6 5 7 QWED PL Chapter E 2 Gra
33. gt lt angle_ of variaton gt Sets beam parameters PROFILE lt type gt lt par_a gt lt par_b gt lt file_name gt Sets PML profile parameters lt type gt 0 1 2 SYMMETRY lt symm_v gt lt symm_h gt Defines port vertical and or horizontal symmetry ies lt symm_v gt lt symm_h gt 0 or 1 if 1 the symmetry is on WAVEFORM lt shape gt lt f1 gt lt f2 gt lt duration gt lt amplitude gt lt delay gt lt file_ name gt Defines excitation parameters accordingly to I O port dialogue 1 0 7 for no excitation delta defined by user text file WAVEFORM2_ lt amplitude_im gt lt delay_im gt Defines imaginary parts of excitation parameters for periodic circuits accordingly to I O port dialogue ENDPORT End of the port frame Here is the review of the basic points about port definitions in UDO There are two types of ports vertical and horizontal A vertical port consists of one line base of element and has non zero height A horizontal port consists of four lines closed rectangle and its height is zero Each port has an additional line The first point of this line determines excitation probe points of the port Even if such a line is dummy it has to be placed at the end of the ports frame For vertical ports this additional line is shifted by the interpreter to the half of the height of port Reference port should be placed immediately after the corresponding I O port Note th
34. input output functions Note that in the case of Mesh snapping planes the size of the rectangle introduced to mark the plane is of no importance It is displayed only to recall to the user where the plane is The user should make it of the size least disturbing to the images of the structure or even choose the white colour to make it invisible A keyboard action SHIFT M or SHIFT m moves the x and y mesh snapping planes to the boarders of the project and normalises their lengths of the displayed markers to a standard cell sizes The right part of the dialogue allows fast inserting of electric mesh snapping planes Only orientation needs to be selected and one coordinate position needs to be specified and QW Editor will draw the plane with default dimensions and colour M Special planes and boundaries 3 x Force mesh Mame f Electric electric i Magnetic Orientation Neutral I Weak o parallel to YZ 0 Y parallel to x 0 2 parallel ta 1 i Box Prasition Connection Insert Advanced Help Cancel i Fig E 2 4 2 1 A dialogue for drawing special planes and boundaries Another group of application of the special planes is in defining and connecting the subcircuits of the QW Simulator or connecting the QW Simulator to external simulating tools QW Editor v 6 5 49 QWED PL Chapter E 2 Graphical editor E 2 4 3 Editing ports Once a port in a general sense has been defined it
35. one an element cubic3 Note that o Both bottom and top of combined elements have the height equal 0 The actual height of the element is defined by the difference between the levels of the bottom and the top o The declaration of the top must immediately follow the declaration of the bottom The 4 th parameter indicates the name of the medium of which the element is made The name of medium must be one of those used in the Medium Library of the current project The assumed parameters of the medium are those found in the Medium Library unless they are overwritten in the UDO script by an instruction MEDIUMPAR that gives new values of the parameters for the particular medium The 6 th parameter indicates the orientation of the contour of the element IN indicates that declared medium 4 th parameter is placed inside the defined left counter clockwise oriented contour This is a typical choice and practically the only one recommended to our users Theoretically we have an option OUT placing the declared medium outside the left oriented contour but this is an option introduced for some very special applications and not recommended for general use It may be noticed that while the first element has the orientation IN the second one orientation INe and the third one orientation INn Actually the declaration of IN and INe gives the same result the top and bottom of the element enforces an E plane of FD TD grid as defined in Section U
36. rest of the UDO script Example faper udo The following example will show the use of the while loop in generation of a combined element of circular bottom and top comment Tapered section bitmap taper bmp PAR Object name onam taper PAR radius1 r1 r1 5 PAR radius2 r2 12 2 PAR height h h 10 PAR sectors n n 16 PAR medium med metal ENDHEADER TEST n gt 2 n should be greater than 2 step 360 n OPENOBJECT onam ELEMENT z 0 5 med Taperb IN bottom NEWLINE x r1 y x r1 cos step y r1 sin step 1 3 while i lt n do ADDLINE x r1 cos i 1 step y r1 sin i 1 step I endwhile CLOSELINE ENDELEM QW Editor v 6 5 83 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language ELEMENT z h 0 6 med Taperb IN cover NEWLINE x 12 y x 12 cos step y 1r2 sin step 1 3 while i lt n do ADDLINE x r2 cos i 1 step yt 1r2 sin i 1 step I endwhile CLOSELINE ENDELEM CLOSEOBJ i Quick Wave 3D 2D coa Editor 6 5c 2006 08 03 H1 noname File Parameters Windows Project Tools Help CELETTE an Add Object C Program Files Q ED OW IE xr zzl go SD View Cancel Tapered section Description Phase FINAL 0 28 ve Fig E 3 5 1 The Draw Object dialogue for taper udo and 3D views of the produced object E 3 6 Defining ports boxes mesh snapping planes postprocessing and circuit parameters We as
37. screen o It should be noted that each of the combined elements if present is displayed on the list as a composition of two elements of the same name describing the lower and upper plane of the element The types of these elements indicated on the list are bottom and cover correspondingly Each of them can be selected separately However if you move or modify bottom cover will be moved modified automatically in the same way On the contrary cover is moved and modified without influencing bottom Cover has nominal height equal zero while bottom has nominal height equal to the actual height of the combined element and equal to the difference in the levels of the bottom and the cover However remember that both these values are purely nominal and the only way to change the height of the combined element is by changing the level of its cover 99 o Each element can be marked or unmarked using the and al boxes When an element is marked a letter M appears by its name On the graphical display marked elements will be distinguished from unmarked ones by thick line contours The elements are marked to point out those which should be subject to the subsequent Edit Reproduce operations o Each element can be also defined as passive or active for Edit Join operations When this is done a letter P or A appears by the element s name When performing the Edit Join operations the active elements will dominate over the passive
38. set the simulation time long enough to allow the reflected wave to bounce back a few times producing well converged simulation results Moreover in this group we have one checkbox It enforces suspension of the simulation process after N iterations or in other words after time T In general AMIGO tries to optimise the mesh taking into account the requested number of cells per wavelength in each medium as well as the geometrical properties of the structure Although QW 3D uses a conformal FDTD method the accuracy of simulation may be enhanced when the geometrical details are well synchronized with the actual FDTD mesh This can be obtained by introduction of mesh snapping planes In general those planes may be of type E imposing that the mesh snapping plane is aligned with the FDTD cell edge where the tangential E field is calculated M imposing that the mesh snapping plane is aligned with the centre of FDTD cell where tangential H field is calculated N neutral imposing that a mesh snapping plane of either E or M type is generated in that place In most applications the E type of mesh snapping planes are preferable because they impose the best conditions for accurate analysis of the most critical parts edges of metal elements in the structure Thus in general AMIGO tries to generate the mesh snapping planes of E type along edges of geometrical elements and passing through their vertices However in many practical projects suc
39. system o Notepad a text editor Notepad supposed to be the default one o Simulator the QW Simulator when invoked from here will be started without any reference to the QW Editor In particular the Export operation on the current project will not be performed o SAT Viewer This commands causes that the shape of the 3D structure is considered in QW Editor is exported in ACIS SAT format and the free HOOPS 3D Viewer is called to visualise it o SAT Filter This external optional application is used to convert files available in ACIS SAT format into UDO format which in turn is read by QW Editor into the current project Note that the sat file must be prepared with a view to its application in 3D EM modelling It must be internally consistent and must provide a 3D volumetric descripton In particular shell type geometries are illegal since they cannot be automatically converted into volumes even if they appear correct in SAT Viewer and analogous viewing tools ACIS SAT Filter is a joint product of QWED and Vector Fields Ltd o DXF Converter This internal QW Editor option converts chosen files available in DXF format into UDO format which in turn is read by QW Editor into the current project o UDO Editor a convenient text editor for UDO files o My Tools a group of tools assigned to this group by Visible in My Tools option of the Set Tools dialogue o Set Tools opens a dialogue for setting new Tools a
40. the QW Simulator the QW Editor performs the following tasks e It defines the sequence of operations to be executed by the QW Simulator to perform the simulation according to the set of parameters As a result a tasker file project_name ta3 is created This is the project tasker file or in other words a text file containing the commands for the QW Simulator A closer look at the directory in which the wgtocx1 ta3 has been created reveals that there is also another tasker file project_name0 ta3 This is a copy of the project_name ta3 with one exception instead of generating the mode templates the QW Simulator is asked to read the previously generated templates from disk This allows us to avoid generating the templates when we know that they are the same as the ones previously calculated and saved on the disk e It prepares the files containing the description of the analysed structure divided into FDTD cells Those files are called project_name sh3 for the entire 3D structure and auxiliary files describing the consecutive ports each of them called by the port name with the extension sh3 e t prepares the files containing the description of the parameters of FDTD simulation Those files are called project_name pa3 for the parameters of 3D analysis and auxiliary files describing the parameters of the consecutive ports each of them called by the port name with the extension pa3 However note that the project_name pa3 file will not be created i
41. too long or incorrectly situated the project may occupy only a small part of the window and be poorly visible QW Editor v 6 5 23 QWED PL Chapter E 2 Graphical editor K 2 xX nro p ai Step Poo shitt jo p Select U Select Wisible Cancel Fig E 2 2 1 6 2D Axes Setting dialogue window i E e Grid Snap By defining the grid we set an array of regularly spaced points to be displayed in the 2D window They can be helpful in defining the shape of the structure directly on the screen When the snap is on any point considered in the 2D window adopts only coordinates discretized with the snap value as the basic increment It is strongly recommended that the snap is always on and its value is not lower than the accuracy with which the dimensions in the project are defined If the snap is off two faces of adjacent elements which are seemingly adherent may in reality form very thin slots which make the analysis slower and less accurate if not erroneous Similar effects may appear for example if we know that the dimensions are defined with 10u accuracy but use the snap of Iu E Grid Snap Paramete 2 x Grid W Snap Step Shift Step Shift s G g5 on objects File fanidPen Cancel ox E Fig E 2 2 1 7 Grid Snap Parameters dialogue window e Coordinates This command allows to change the local coordinates from rectangular to polar ones Note that polar coordinates will only be used for
42. v 6 5 73 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language PAR outer dia2 oud2 9 PAR length of I O segment 11 15 PAR length of middle segment 12 30 PAR input to reference dist rdist 5 PAR I O port param file pf NO PAR number of sections nsec 32 ENDHEADER TEST ind gt 0 amp amp oud1 gt 0 amp amp oud2 gt 0 Diameters must be positive TEST 11 gt 0 amp amp 12 gt 0 Lengths of sections must be positive TEST oud1 gt ind amp amp oud2 gt ind Inner dia must be smaller than the outer ones OPENOBJECT oname calls to three coaxial line segments CALL coax2 cxv1d udo seg1 l1 ind oud1 air nsec x y z 11 10 CALL coax2 cxv1d udo seg1 12 ind oud2 air nsec x y Z 10 CALL coax2 cxv1d udo seg3 I1 ind oud1 air nsec x y z 12 10 CLOSEOBJ The above script can be considered as an example of UDO programs Each of them is composed of two parts header contains the information that will appear in the header display of the UDO namely O a comment line describing the object to be displayed in both library header and the UDO header bitmap file name indicating the name of the file containing a 110x110 pixels bitmap to be displayed in the UDO header The software looks for the bitmap first in the directory of the considered UDO and then in the directory elib bitmaps If a proper bitmap is not prepared nobitmap bmp name is recommended Otherwise at e
43. without path and extension of the current project o lt PROJECTPATH gt returns the path of the current project o lt PROJECTFULLNAME gt returns the path and filename without extension of the current project o lt INSTALLDIR gt returns the path of the QuickWave installation from where the QW Editor was started o lt UDOFULLNAME gt returns the path and filename with extension of the UDO file chosen from the UDO Library dialogue Section UG 2 8 2 The Visible section contains three options o Not Visible the tool will be not visible in the Tools menu Fig E 2 1 5 1 o Visible in Tools the tool will be visible in the main Tools menu Fig E 2 1 5 1 o Visible in My Tools the tool will be visible in the Tools MyTools menu Fig E 2 1 5 1 The user can add change or delete the tools via New Ren and Del buttons Please note that the names of the seven predefined tools can not be changed and this tools can not be deleted E 2 1 6 Help group of commands Help group contains two options About shows general information about QW Editor Contents opens the electronic manual prepared in HTML Ud Quick Wave 3D 2D coa Editor File Parameters Windows Project Tools Help IO aH m x 2 B EP Contents ak About Ctrl A Fig E 2 1 6 1 Help group of commands of QW Editor menu QW Editor v 6 5 16 QWED PL Chapter E 2 Graphical editor E 2 1 7 Overview of icons within QW Editor main window B
44. 2 gt lt medium name gt lt name gt Start of section frame where lt level gt level of section element s base usually relative to predefined origin variable Z lt height gt height of upper element if equal to zero suppresses Z activity lt height2 gt height of lower element if equal to zero suppresses Z activity lt medium name gt name of element s medium if there is no such medium air is forced lt name gt max 20 characters name of element suffix U D is added for upper lower element ENDSECTION End of section frame E 3 4 Variables functions arithmetic expressions and file reading The UDO language is simple Here are some general rules Declaration of the variables is automatic and is done by Declaration as one of the UDO parameters In a such case it is assumed to be numerical or text depending on the declared initial value Appearing on the left side of an equation In such a case it is assumed to be numerical or text depending on the value of the right side of the equation Strings not declared as variable names and not recognized as key words of UDO language are treated as text Function VAR text returns the value of the variable of the name equal to text All variables are global within one UDO The values of variables can be transmitted to another UDO only through UDO parameters QW Editor v 6 5 SO QWED PL Chapter E 3 Syntax of the User Defined Object UDO lan
45. 2D window describing a chosen section of the 3D structure QW Editor v 6 5 12 QWED PL Chapter E 2 Graphical editor Open 3D opens a 3D window showing the 3D structure in OpenGL Project Info opens a window with basic information about the project status its name description mesh objects and a list of paths that is helpful in software maintenance and user support It also contains warning messages issued by Export procedures or by Parser interpreting UDO commands Attention gt More elaborate description of operations on these windows is presented in the following Sections E 2 2 and E 2 3 The user can open as many windows as may be useful for visualisation of the circuit gt The structure can be defined modified only in a 2D window located in the XY plane This is why such a window is called 2D QW Edit All other windows 3D or 2D in other planes than XY are for visualisation only and they are celled QW View Any changes of dimensions or shape of the designed structure introduced in one of the QW Edit windows will automatically appear in all the other displayed windows o Refresh command shows in all windows the most recent state of the project including changes of mesh or local coordinate system o Arrange command can be especially useful when many windows are open and some may have been erroneously pushed out of the screen Fuzzy appearance of the project may result from its moving between two computers worin
46. FF lt value gt Sets port effective permittivity e LUMPED lt component gt lt options gt lt resistance gt Sets parameters for lumped source probe port lt component gt index 0 to 5 for Ex Ey Ez Hx Hy Hz lt options gt for 0 lt resistance gt is used 1 denotes INF resistance 2 is self adjust option e LUMPIMPPAR lt type component gt lt Rp gt lt Lp gt lt Cp gt lt Rs gt lt Ls gt lt Cs gt Sets parameters for lumped impedance lt type gt index 1 to 5 for Parallel Series Drude Debye Lorentz lt component gt index 0 to 2 for Ex Ey Ez lt Rp gt lt Lp gt lt Cp gt lt Rs gt lt Ls gt lt Cs gt equivalent circuit parameters QW Editor v 6 5 87 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language MODE lt mode_index gt Sets port mode 1 Quasistatic 8 multi TEM 9 planeTEM otherwise Dynamic TEMPD lt method gt lt match_freq gt lt within gt lt from gt lt to gt lt step gt lt component gt lt iterations gt Sets parameters for port dynamic template accordingly to I O Port dialogue controls lt method gt 0 1 automatic manual MTEM lt medium_name gt lt potential gt Assigns potential to metal materials in port PLWAVE lt phi gt lt theta gt lt polarisation gt Sets plane wave angles PLWBEAM lt beam_type gt lt neck_origin X gt lt neck_ origin Y gt lt neck origin Z gt lt neck diameter
47. G 2 1 With the declaration of INn the bottom and top of the element enforces a neutral mesh snapping plane which means that there will be either E plane or H plane of the FD TD grid The result of these declarations is visible on the list of elements presented below invoked by Select Element Two first elements are marked with E and the third one with N QW Editor v 6 5 77 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language Name level Height Type Medium Status 1 Bee D g5 ElemetE a ait a 2 pism 1210 feomtinedteovene or fa feses nas ete foe Syntax of introduced above and similar UDOs commands e ELEMENT lt level gt lt height gt lt type gt lt medium name gt lt name gt lt spin wire gt Start of element frame where lt level gt level of element base usually relative to predefined origin variable z lt height gt height of element for combined elements 1s forced to zero lt type gt type of element 0 simple element 5 bottom of combined element 6 cover of combined element lt medium name gt name of element medium if there is no such medium air is forced lt name gt max 20 characters name of element lt spin wire gt orientation of element edge or wire marker IN INe INn medium fills inside the defined left counter clockwise oriented contour These are typical settings practically for all applications except of wires IN and IN
48. OPENF 81 82 98 OPENOBJECT 74 76 PAR 75 98 PERIODIC 90 PLWAVE 88 PLWBEAM 88 PORT 86 PORTEXC 85 86 87 PORTPAR 86 87 95 96 PORTPAR2 86 87 PORTPOSTP 86 87 PROFILE 88 PRONY 90 READF 81 82 83 98 READS 82 REDRAW 92 RENAME 92 ROTATE 92 SECTION 80 SETATTR 78 SETOBJMED 79 SETPEN 93 SETSUSPFLAGS 95 SHIFTM 92 SKIDIFF 89 SLICINGPHASE 95 SMNDIFF 89 STL 82 STR 82 QWED PL Chapter E 5 Index SYMMETRY 88 UDO interpreter 75 81 96 TEMPD 88 UDO language 70 73 80 83 85 91 96 TEST 74 75 User Defined Libraries 69 THERMALPAR 79 View group of commands 37 42 UNITS 90 windows VAR 80 82 Info Mesh 27 VAWEFORM 88 Level 23 VAWEFORM2 88 Line change 29 XCOORD 80 Point Change 28 YCOORD 80 Windows group of commands 12 ZCOORD 80 QW Editor v 6 5 Ill QWED PL
49. Yi Zip X2 Y2 Z2 Inserts STL format section arithmetic expression Function converting arithmetic expression into string symm v symm h Defines port symmetry method match freq within Defines dynamic template data from to step component iter logical expression text Test and validate expression med name ini temp spec heat Material thermal parameters setting therm cond X Y Z space freq Defines project units text_expression Function returning value of the variable given as the text expression WAVEFORM shape f1 f2 duration Defines waveform parameters amplitude delay file name WAVEFORM2 amplitude im delay im Defines additional waveform parameters for periodic circuits Standard control command XCOORD item _type name n Function returning x coordinate of n th point of the element QW Editor v 6 5 102 QWED PL N rr O J s lia wg m 0 IZ a B z O iim gt j T lt gt JJ lt gt J Chapter E 3 Syntax of the User Defined Object UDO language YCOORD item_type name n Function returning y coordinate of n th point of the element ZCOORD item_type name n Function returning z coordinate of n th point of the element Operators increment decrement change sign addition subtraction multiplication division A power lt gt gt lt logical conditions parenthesis instructi
50. _type gt lt range gt lt command gt This commands is used to Mark or Unmark elements or objects for further operations of movement or reproduction lt item_type gt subject to operation ELEM elements ELEML local elements those created in the currently open object OBJECT objects OBJECTL local objects those created in the currently open object lt range gt range of operation name name of a single element or object to be marked ALL all elements or local elements or objects or local objects ALLACTIVE all active elements or local elements ALLPASSIVE all passive elements or local elements LAST last created element or object lt command gt operation SET mark element or object RESET unmark elements or objects e JOIN lt operation gt Joining elements according to the rules explained in Section UG 2 12 1 lt operation gt type of join operation QW Editor v 6 5 91 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language CUT INTERSECT GLUE SHIFTM lt dx gt lt dy gt lt dz gt Shifting all the marked elements or objects lt dx gt lt dy gt lt dz gt requested shift in the direction of the main axes MIRROR lt xy gt lt xz gt lt yz gt Performing a mirror reflection of all the marked elements or objects with respect to the planes z 0 or and y 0 or and x 0 lt xy gt lt xz gt lt yz gt Boolean variables 0 or 1
51. a ctrl OD T Edit Point 3 gt k Eh SE So z Edit Port Edit Line E Edit Element ER Edit Object SE Select Element SO Select Object Pr Reproduce Cm Join i er Cut Glue Ce Intersect Fig E 2 2 2 1 Edit group of commands Redo revokes up to N undo commands Edit Point To move a point belonging to an element we must move the local coordinate system to the correct level This can be done by using Setup Level or Edit Select Element commands After this is done invoking Edit Point command changes the cursor mode square cursor and we are ready to change the position of any point belonging to any element having the base at this level To do this we approach the cursor to the point click the left button and move the cursor The point is being moved with the cursor Pressing the left button again will stabilise the new position while pressing the right button will cause its return to the original position We can also press K to be able to introduce the new position of the point using the keyboard Note that to get out of the Edit Point mode we can press E on the keyboard EscEdit eS 22 O 0 218 Y 1 068 Delete Cancel Fig E 2 2 2 2 Keyboard Entry and Point Change windows fe Keyboard Entry i Edit Port This command is used to move a port or change its parameters Note that to get out of the Edit Port mode we can press E on the keyboard QW Editor v 6 5 28 QWED PL Chap
52. a2 a The software enforces S2 S and arg S1 targ S22 2arg S12 n o The software will not verify your declaration regarding reciprocity and losses but it will ignore the declaration of lossless 2 port if the number of ports if different e Smn at reference planes This is a general case in which we perform N simulations exciting the structure from N different ports and then compose the complete S matrix from N sets of partial results Each of these sets corresponds to excitation from port i when the software calculates the parameters Sy in the same way as the parameters S are calculated in the Sk at reference planes postprocessing When all N sets are available the software corrects all the S matrix elements for imperfect absorbing at all ports reciprocity is irrelevant at this stage Thus the final results of Smn calculation may somewhat differ from the N sets of partial results There are three regimes of running the Smn at reference planes postprocessing o In the sequential regime the software performs N consecutive simulations with excitation from each of the N ports Each simulation lasts for a predefined number of FDTD iterations specified by the user in the terations per port box Note that during one simulation we obtain Sx elements like in the Sk1 at reference planes postprocessing and these parameters either uncorrected or partially corrected for imperfect absorbing boundaries are being displayed Only after compl
53. ach object call the program will stop with a warning about a missing bitmap parameters the list of parameters to be later modified from the header containing the parameters description to appear in the UDO header its internal name in the UDO script and the initial value body contains all other commands not included in the header Between header and body ENDHEADER separator is necessary Commands available for application in the body will be described in this and subsequent sections Below we will discuss only those used in verstepa udo O TEST command is not obligatory but helpful It helps to avoid entering unreasonable or inconsistent parameters When the condition in the TEST argument is not met the commands listed in the UDO script after the TEST are not executed and a warning is issued Thus it is convenient to put the TESTs just after the header CALL command executes a call to another UDO to a nested object In our case we have three calls to the same coax2 cxv1d udo describing one segment of coaxial line but with different parameters The list of parameters includes the path to the called cxv1d udo all parameters of the cxv7d udo header the position of the called object x y z in the co ordinates of our project the total number of parameters This way we generate three segments of coaxial line as shown in Fig UG 2 8 2 1 As requested in the calls the consecutive segments will be named seg1 seg2 and
54. action nor for FD probing ere Excitation Parallel Series Drude Debye Lorentz Wavelorm F z hea o A Lumped impedance NA 0 Rp Eo Fis 50 Ohm requency LOAD Lp fi OB Ls It OB nH fa GH Cp 0 106 Cs 0 106 pF E N Component Ey Duration Mo of 10 ports 3 NO WARNINGS Amplitude Delay na Set All aj el o Net Prev Get f fo Muli TERA _ Cancel Help Put Fig E 2 5 1 3 2 The relevant parts of the I O Ports Parameters dialogue window in the case of a lumped impedance E 2 5 1 4 I O Port parameters in the case of free space excitation by a plane wave or a Gaussian beam Free space excitation by a plane wave or a Gaussian beam is a subject of several examples described in Section UG 2 6 Here we will not repeat the technical discussions concerning such an excitation Let us only point out that the plane wave is a limit case of the Gaussian beam when the neck diameter tends to infinity The Gaussian beam has been introduced to model finite spot size illumination in optical or quasi optical problems The I O Ports Parameters dialogue for the case of free space excitation is shown in Fig E 2 5 1 4 1 QW Editor v 6 5 57 QWED PL Chapter E 2 Graphical editor Name INCIDENT deg BeamaD 20 PLANE Wave llluminatior deda jo Ho of 140 ports 7 f TEM B30 ff B20 HM Dia f NO WARNINGS E8 1 0 Ports Parameters 2 x Excitation Waveform plaw Phi fo sinusoidal Th o N
55. ane which is then filled with wires of a horizontal H or vertical V orientation The number and locations of wires in the grid automatically adjusts to the mesh and mesh changes Their orientation is chosen by the user in Element Change dialogues of QW Editor Tab E 2 2 7 1 specifies the correspondence between the horizontal vertical H V terminology of QW Editor and the electric field component effectively set to zero Wire grids can be defined through the wiregrid udo file prepared by QWED and delivered together with QW 3D software Manual definition of wire grids is also possible although less convenient ASBC parallel to plane ASBC orientation ASBC definition horizontal h Element Change cdta Flement Change cdta Hame Elem Hame inne Type Wie Tipe Elemert E Haight S Height 0 Paianeleis Hedum Harma meia Edi Inside Outside Hadum meis e Dreialion Wire damele 0 2 Oha HY Amigo stabs _ Mak C Disable C Active C Soft Passive O Hadedges 7 Hard C Biphass Amigo stalus Hak C Disable T Active C Soft l Passive gt Hard edges pm h Hard L re Wire erid parameters Onentator C H Y Wie dianeter 02 Tab E 2 2 7 1 Definition of horizontal and vertical wires in QW 3D software Upper table shows the meaning of horizontal and vertical depending on the plane of ASBC The Element Change dialogues apply and to a wire element left and to a metal eleme
56. antages of application of parameterised objects in electromagnetic design e Inthe vast majority of applications engineers design structures which can be composed of typical primitive objects by simple putting them in proper place or by exercising Boolean operations on them e In many practical cases design engineers deal with one type of a microwave structure for a long time Not changing the general shape they modify its dimensions to optimise performance or to redesign the device for a different set of parameters or a different frequency band In such a case the most convenient way to proceed is to define the investigated structure as User Defined Object or as a set of such objects with some dimensions introduced as parameters To change one of these dimensions it will be sufficient to call the object once more and to introduce new values of the parameters the operation which can be accomplished in seconds e Parameterized UDOs open new horizons for running QVV 3D in an automatic optimisation loop using QW OptimiserPlus the old QW Optimiser or other external optimisers like for example those available in MATLAB TOOLKIT see Section S 3 7 The QW 3D package includes QW ObjectGenerator QVV ObjectGenerator is essentially an interpreter for source programs provided by QWED in a form of library UDOs or prepared by the user in a specially developed UDO language These source programs are stored in files with udo extension It is recommended tha
57. arameters in the case of lumped sources probes or lumped impedances E 2 5 1 4 I O Port parameters in the case of free space excitation by a plane wave or a Gaussian beam E 2 5 1 5 I O Port parameters in the case of QW V2D ports E252 F233 E 2 5 4 Processing Postprocessing Media parameters Units E 2 6 Application of QW Editor using library objects QW Editor v 6 5 3 QWED PL own N 13 13 16 17 17 19 20 21 ZY 34 38 38 39 42 56 Table of Contents E 2 7 File exporting and starting the simulation from QW Editor E 2 7 1 Export and Run commands E 2 7 2 How to assure the proper mesh generation E 2 8 Command line options of QW Editor E 3 SYNTAX OF THE USER DEFINED OBJECT UDO LANGUAGE E 3 1 What is the User Defined Object E 3 2 Structure of a single UDO and calls to other UDO s E 3 3 Defining elements combined elements and materials E 3 4 Variables functions arithmetic expressions and file reading E 3 5 Loops in UDO language E 3 6 Defining ports boxes mesh snapping planes postprocessing and circuit parameters E 3 7 Moving the elements copying them and controlling their intersections E 3 8 Biphased element and objects QW 3D only E 3 9 Controlling the mesh E 3 10 Files used by UDO language and their location E 3 11 Optimising with UDO E 3 12 UDO commands and functions in alphabetic order E 4 FILES CREATED OR USED BY QW EDITOR E 4 1 Files used by QW E
58. ase of 3D projects The PML ABC has not been implemented in QW V2D The interpretation of lumped sources or probes is somewhat different in QVWV V2D A point becomes a ring and thus a point source becomes a ring source with the angular distribution of current as declared in Circuit Parameters The plane wave excitation options and the lumped impedances cannot be used in QW V2D E 2 5 2 Processing Postprocessing Time domain data such as time evolution of fields or currents and voltages at lumped ports can be accessed in QW Simulator at any time and any location within the structure Data in the frequency domain such as S parameters is produced by means of the Fourier transform which must be performed on selected time domain quantities throughout the simulation Additional memory must also be allocated at the beginning of the simulation process For these reasons the user must indicate the required frequency domain results before starting QVV Simulator This is done in the Parameters Processing Postprocessing dialogue box as in Fig E 2 5 2 1 QW Editor v 6 5 58 QWED PL Chapter E 2 Graphical editor Let us discuss the parameters describing frequency domain data which will be extracted from the FDTD analysis There are six types of Processing Postprocessing algorithms and several additional options Any or all of them can be selected for one simulation and each has its own frequency band FD probing At all I O ports of the lumped s
59. ased on the observation that since the FDTD method simulates natural processes in the device the necessary number of iterations and the computing time directly QW Editor v 6 5 5 QWED PL Chapter E 1 Fundamentals of the method of analysis depends on the loaded Q factor of the analysed structures High Q resonant structures need much longer computing time On the other hand the Q factor directly influences the frequency resolution needed to reproduce the characteristic of interest with sufficient accuracy Thus declaration of the frequency resolution is sufficient to calculate the needed number of iterations The user is typically well aware of the frequency resolution he requires to make the simulation of the frequency domain characteristics informative and thus application of this criterion is quite straightforward A concern may arise that there are structures of a very low Q but very large size and thus the long simulation time is needed to simulate displacement of the virtual pulse through the structure However the size of the structure also directly influences the variations of the frequency domain characteristics and the user can usually easily predict the frequency resolution needed to take into account the size factor To make such a prediction easier Amigo informs the user how many times the pulse would travel across the structure with the assumed number of iterations Resuming we recommend the application of Amigo as a basic way of pre
60. at modifying an object really means cancelling it and recreating That is why during this operation all the port parameters are also cancelled and set to default values In practical application of objects this would cause some inconvenience which may be avoided the following way Before the modification of an object including ports the parameters of each of the ports can be saved on disk using Put command in the I O Ports dialogue Then after modification of the object they can be restored using Get command in the same dialogue But the best solution is to execute the Get command automatically from UDO using the GETIOPAR command Example The library object portox udo comment Port for transmission in X dir with excitation in the port centre bitmap portx1 bmp PAR port name pname portox PAR port height Z direction hpo 3 QW Editor v 6 5 88 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language PAR port width X direction wip 3 PAR port to circuit dir UP or DOWN pdir UP PAR 1 inp 2 outp kind 1 PAR port ref distance ptr 3 PAR port IOP file pio NO ENDHEADER TEST kind 1 kind 2 port can be only 1 input or 2 output TEST pdir UP pdir DOWN energy transmission can be only UP or DOWN y1 0 5 wip OPENOBJECT pname portkind INPTEMPLATE actref pdir if kind 2 do portkind OUTTEMPLATE if pdir UP do actref DOWN endif if pdir
61. ate by a proper choice of excitation in template generation Such a process has been exemplified in Sections UG 2 2 3 UG 2 2 5 Further choices regarding each I O port and in particular its excitation and template generation are made in the I O Ports Parameters dialogue invoked via Parameters I O Ports command We will discuss these choices in the Section E 2 5 QW Editor v 6 5 48 QWED PL Chapter E 2 Graphical editor E 2 4 2 Drawing mesh snapping planes and symmetry planes After invoking the command Draw SPlanes boundaries we obtain the dialogue of Fig E 2 4 2 1 The most frequently used application of this command will be to force mesh through the introduction of a mesh snapping plane It is like indicating a plane to which the FDTD mesh must adjust e electric forces cell edges i e a plane whereat the tangential electric field components are calculated e magnetic forces cell centres i e a plane whereat the tangential magnetic field components are calculated e neutral forces either magnetic or electric plane depending which distorts the existing mesh to a lesser extent e weak forces an additional plane between the FDTD mesh planes whereat additional geometry information will be extracted for better approximation of complicated shapes at subcellular levels in AMIGO operation it may force electric plane if this within mesh constraints set by the user Technically mesh snapping planes work like a port without executing the
62. ates mesh snapping planes cf Setup Mesh command Section E 2 2 1 If the mesh generator detects two such planes enforced by two different elements at different levels but very close to each other it will create a very thin layer of cells What may happen in some specific cases is that these two levels should really be identical and they have been shifted apart as a result of previous operations on elements The difference may also arise when we have two elements at the same physical level and of the same physical height but one of them is simple while the other combined For the combined element the levels of bottom and cover are explicitly remembered by QW Editor For the simple element QW Editor remembers its height and the level of bottom and calculates the level of cover therefore The result may be different from the level of cover of the combined element The thin layer of cells created in such cases would be unnecessary prolonging the simulation time and deteriorating the accuracy To avoid such problems QWV Editor precedes the actual mesh generation by snapping of all coordinates to 10 in current units cf Section E 2 5 4 This measure has proven sufficient in all typical applications but nevertheless the user is advised to consult the Mesh Splanes info Section E 2 2 5 whenever substantial changes in the project have been made E 2 8 Command line options of QW Editor It is possible to call QW Editor from a command line w
63. ator the default path and filename is lt INSTALLDIR gt qwbin ker1 exe and the default argument is lt PROJECTFULLNAME gt ta3 SAT Viewer the default path and filename is C Program Files HOOPS 3D Part Viewer v13 00 for ACIS bin nt_i386 acishoops3dpartviewer exe and the default argument is lt PROJECTFULLNAME gt sat The SAT Viewer installation is available on the QuickWave CD SAT Filter the default path and filename is lt NSTALLDIR gt bin sat2udo exe and the arguments are disabled they are added automatically depending on the options in the SAT Filter options dialogue DXF Converter the default path and filename is lt INSTALLDIR gt qwbin dxf2udo exe and the arguments are disabled they are added automatically depending on the options in the DXF Converter options dialogue UDO Editor the default path and filename is INTERNAL and there are no default arguments The user can change path and filename via Set Path and Set Filename buttons The user can also insert an internal variable via Insert Var button and choose the variable from the Insert Variable dialogue QW Editor v 6 5 15 QWED PL Chapter E 2 Graphical editor Jd Insert Variable Eg lt PROJECT NAME gt lt PROJECTPATH gt lt PROJECTFULLNAME gt lt INSTALLDIR gt SUDOFULLNAME gt Cancel Fig E 2 1 5 3 Insert Variable dialogue The predefined QW Editor variables are o lt PROJECTNAME gt returns the filename
64. b must exist and it is the first one always considered by the QW Editor The user can then switch to other libraries from within the Parameters Media dialogue box e elib contains udo files with description of external objects see Chapter E 3 Its bitmaps subdirectory contains bmp files with bitmaps of corresponding external objects If an appropriate omp file is not found nothing happens except that the object is not visualised Let us now proceed to project files of QW Editor As explained in Chapter E 2 the QVV Editor allows to define geometry of the circuits to be analysed as well as parameters of the analysis All these data for each project are stored in project_name pro file To limit the risk of losing important files in the case of hardware or system problems a back up file of the project file is created upon a Save operation under the name project_name pr1 Upon a successive Save operation project_name pr1 is renamed to project_name pr2 Let us recall that a short description of each project is introduced by the user in the Description line of the Parameters Circuit type dialogue This short description is naturally stored in the project_name pro file However some users may wish to maintain a more detailed description about their projects While in QW Editor please press the T button of the main toolbar activating the external text editor A text file project_name txt will be created in the directory containing project_na
65. be needed for 3DP 3D periodic In the case of 2D Vcoa denoting axisymetrical structures two dimensional in cylindrical coordinates we need to define proper angular variation i Circuit Metal losses bandwidth Narrow Angular variation Dielectric Magnetic Metal f Decade i Two Decades ft 3DF Singularity conections Density SAR Phase shift per perad rad A er bp Default medium Iv Z fo on C Metal al Cancel Fig E 2 2 1 2 Circuit dialogue window We further have a choice of the default medium This type of medium will be assigned to any volume in the project which has not been explicitly defined as made of some other medium We have a choice of two types of default media Metal convenient for shielded waveguide structures or air which would be convenient for radiation problems Note the following o The choice of the default medium is important and accidental change of it may lead to wrong simulation results That is why the current default medium is constantly signalled in the header of each 2D window where we can see the expression IN METAL when the default QW Editor v 6 5 2I QWED PL Chapter E 2 Graphical editor medium is Metal or IN AIR when the default medium is air Moreover the background colour of the window changes see the View Options On the entry to a new project the default medium is Metal Thus if you want to model a free space propagation l
66. besides setting the tangential E field components to zero singularity corrections will be applied to the H fields encircling the wire and E fields perpendicular to the wire The X and Y origin coordinates are irrelevant Manual definition of XZ and YZ wire grids A grid of wires parallel to the XZ plane can be created by drawing an X oriented wire in a standard way see Section E 2 2 3 but of non zero height Note that O Default orientation of wires in the grid is horizontal x oriented The uppermost wire will not be created For example if the wire element is drawn at level z 0 of height h 5 and the FDTD mesh is at z 0 1 2 3 4 5 the individual wires will be set only at z 1 2 3 4 Wire orientation can be changed to vertical Z oriented in the Element Change dialogue which is shown below Tab E 2 2 7 1 and can be invoked by selecting the wire element on the Select Element list double clicking with left mouse button and clicking right mouse button The vertical wires will be of user defined height A However the last wire on the right will not QW Editor v 6 5 41 QWED PL Chapter E 2 Graphical editor be created For example if the wire element is drawn between x 1 and x2 3 and the FDTD mesh lines are at x 0 1 2 3 the individual vertical wires will be set only at x 1 2 Analogous rules apply to wire grids parallel to the YZ plane Y replacing X in the above description Manual definition of XY wire gr
67. by text editing the pro Then the search for the udo file follows the same rules as in the case of udo called by CALL command from UDO scripts as explained below udo files called by CALL command from UDO scripts Let us first establish the meaning of name versus short name and full name We can consider three basic possibilities of specifying file name a my_udo udo b c dir_1 dir_2 my_udo udo c dir_k dir_l my_udo udo In all these cases the short name is the same mMy_Udo udo Thus in case a name is also short name Name in case b is also full name In general name may include any number of directories up from the file location and thus may be anything between short name and full name As we will see the result of CALL command depends on how the name has been specified The interpreter tries to locate the file of given name in the following sequence of steps project directory name by standard File Open command on given name in practice works 1f full name is given project directory short name in consecutive directories set by the user as UDO Paths name in consecutive directories set by the user as UDO Paths short name 6 in elib directory name eee a i T If all six steps are unsuccessful it terminates with an error message bmp files substituted for bitmap variable in the header of the UDO program When considerin
68. calculated using the vector product of the simulated fields and the mode templates to filter out the influence of the modes other than the considered one Nevertheless the presence of other modes may have some influence on the accuracy especially when calculating wide band characteristics of inhomogeneously filled lines That is why it is recommended that the reference plane be kept at a safe distance from the discontinuities which produce a high content of unwanted modes e The position of the reference plane rectangle in the plane perpendicular to the direction of propagation should be exactly the same as of the corresponding port If you move the reference plane graphically on the screen please observe that it is moved only in the direction perpendicular to the port plane use the Zoom function to verify this However the best way to move a reference plane is described below Invoke Select Element command and select the reference plane in question Then press the right mouse button to get into the Edit special planes dialogue window In this plane use Set plane command or Shift command to put the reference plane to the desired position Let us also note that it is possible to define in the same place two different ports operating on two different transmission line modes like for example vertical and horizontal polarisation in a square waveguide In this case we define in the same place two I O ports and assign to each of them different mode templ
69. cant errors As all numerical methods the FDTD method has its limits of accuracy for given computer resources There are two basic sources of errors a Error due to finite discretisation of space finite cell size The division of the circuit into cells called meshing is performed in the QW Editor automatically but it is controlled by the user The user chooses the basic cell size which determines the accuracy on one hand and the computer time and memory needed for the simulations on the other hand The best way to check the level of the discretisation error for a particular application is to analyse the same circuit with different cell size and to compare the results In QVWV 3D reducing the cell size by half brings the space discretisation errors down by a factor of 4 or nearly 4 However it should also be mentioned that the computing time will rise almost 16 times and memory occupation 8 times b Error due to finite computing time used for wave simulation and the stop criteria for FDTD simulations This error results from the fact that calculation of Fourier transforms of the input and output signals is restricted to the number of iterations in which not all the energy injected into the device by the virtual source 1s dissipated in the input and output terminations and on internal losses of the circuit There is quite a simple way of predicting the needed number of iterations implemented in Amigo option see Section E 2 1 2 1 It is b
70. d Modify that will open the window with the object s parameterised dimensions We can change these dimensions and draw the object again Object Change 7 x Mame IN teddy EscEdit Delete Type normal amin Put UDO Modify Mark Cancel PE EEE Fig E 2 2 2 6 Object Change dialogue window e Select Element This command is used when we want to pick up an element on which some operation should be performed We get a dialogue window in which all the elements of our project are displayed For example in the case of wgtocx7 project see Fig E 2 2 2 7 we have seven elements waveguide inner and outer conductors of the coax line and four elements describing the I O ports templates and reference planes for S parameter calculation Here are the typical operations which can be performed using this dialogue window Select element Eo 2 x Type Status waveguid O Element E fait a Bos 59 eemerte dar a oisin 05 int tenstem Boe OS feeen OO E foma ao Absobing 1 E _ S i o Z Yicoarout 105 0 Reference 2 AE W Marked Active Passive Fig E 2 2 2 7 Example of Select element dialogue window displayed for the case of wgtocx7 project QW Editor v 6 5 3 QWED PL Chapter E 2 Graphical editor o To move an element in space in XY plane we must move the local coordinate system to the plane of the base of this element This can be done by a double click over an elem
71. d part at the bottom of the Processing Postprocessing dialogue Refer to Sections UG 2 3 1 UG 2 3 5 for examples of Near to Far applications in air and to Section UG 2 3 6 in other media e FD Monitors It performs Fourier transformation of the six field components in selected sections of the circuit called monitors at frequencies specified in this dialogue In QW Simulator magnitudes of these field components as well as real and imaginary parts of the Poynting vector are accessible via View Fields Monitor command This way of watching the fields is complementary to their unconstrained View Fields display With FD Monitors we need to pre define sections and frequencies of interest but then we obtain fields at multiple frequencies from one simulation with a pulse source Monitors are set by UDO scripts from elib monitors directory FD Monitors postprocessing is available only if at least one monitor has been set Theoretically any number of monitors and frequencies them can be considered However collecting the data for many frequencies and monitors may become quite consuming in terms of computer resources S Parameters extraction options When choosing the option of S parameter calculation we must decide upon the range of frequencies we are interested in and the frequency step The number of frequency points whereat the S parameters are calculated increases to some extent the computing time and memory required However the computing time and me
72. defining if the reflection with respect to the particular plane is to be performed MIRRORX lt xmirror gt Performing a mirror reflection of all the marked elements or objects with respect to the plane x xmurror MIRRORY lt ymirror gt Performing a mirror reflection of all the marked elements or objects with respect to the plane y ymurror MIRRORZ lt zmirror gt Performing a mirror reflection of all the marked elements or objects with respect to the plane z zmurror ROTATE lt angle gt lt x0 gt lt y0 gt Reflecting all the marked elements or objects with respect to the specified axis of symmetry by a specified angle lt angle gt angle of rotation lt x0 gt lt y0 gt coordinates of the axis of symmetry COPY lt xx gt Copying the marked element Note that we obtain a second element of the same name and situated in the same place To distinguish the second element from the original one we can use for example the command RENAME or MARK with the lt range gt LAST lt xx gt a dummy numeric variable irrelevant in the present version REDRAW lt delay gt Redrawing all the elements on the screen with a specified delay When lt delay gt gt 0 the REDRAW operation is performed before the delay when lt delay gt lt 0 then its absolute value is taken as the actual delay and the REDRAW operation is performed after the delay lt delay gt is the delay time in seconds RENAME lt item_type gt
73. del_name gt lt par_1 gt lt par_2 gt lt par_3 gt lt par_4 gt sets dispersive dielectric parameters The model_name options are DRUDE DEBYE LORENTZ SETOBJMED lt obj_name gt lt med_name gt Sets medium of object obj_name to medium med_name if med_name exists in project QW Editor v 6 5 79 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language GRIDHV lt orientation_h gt lt orientation_v gt Declaration of wire grid allowed only inside the frame of the element declared as WIRE see also Section E 2 2 7 ADJUSTP lt x gt lt y gt lt z gt lt r gt Moves all points of the elements at level z close to coordinate x y exactly to x y position Close to means that points at level z are in the square with corners x r y r and x r y r XCOORD lt item_type gt lt name gt lt n gt A function returning x coordinate of n th point of the element lt item_type gt subject to operation ELEM elements ELEML local elements those created in the currently open object lt name gt name of the element in item_type group the first found is taken into account lt n gt the ordinal number of the point the first one is numbered 0 YCOORD lt item_type gt lt name gt lt n gt The same as XCOORD but for y coordinate ZCOORD lt item_type gt lt name gt lt n gt The same as XCOORD but for z coordinate SECTION lt level gt lt height gt lt height
74. dicting the needed number of iterations but we also encourage the users to experiment with other criteria listed below There are two general criteria for terminating the simulation during its interactive operation e During the simulation we can watch the field distribution to find out when the field amplitudes are reduced to negligible values e We can also watch the S parameter curves to find out when their shape stabilises Two other criteria are available in QW Simulator for two important categories of problems e S parameter analysis of shielded lossless multiports QW Simulator integrates power entering and leaving through all the ports The user can watch the power balance curve and stop the simulation when power balance becomes equal to unity in the considered frequency band e Analysis of radiation patterns and return loss of lossless antennas QW Simulator calculates radiation efficiency as a ratio of power radiated by the antenna to power delivered to the antenna by the source The user can stop the simulation when efficiency approaches 100 at the frequencies of interest Note that after introducing losses the simulation time for a particular structure can be reduced The user sets the number of iterations by application of Amigo in the QW Editor or in the so called tasker files see Chapter E 4 and S 4 It is understood that an inexperienced user will start from the Amigo option When the simulation is suspended at the number
75. ditor created by QW Editor or externally E 4 2 Files created by QW Editor and used by QW Simulator E 4 2 1 Basic structure of shape files E 5 INDEX 70 70 70 72 73 73 73 76 80 83 84 90 95 95 96 98 99 104 104 105 106 107 QW Editor v 6 5 4 QWED PL Chapter E 1 Fundamentals of the method of analysis E 1 Fundamentals of the method of analysis The electromagnetic fields are in general characterised by three dimensional Maxwell equations In the Finite Difference Time Domain method FDTD these equations are directly discretised in space and time and solved explicitly The discretisation in space means that the considered domain should be divided into small subdomains called cells Since the time variable is also discretised we calculate the field distribution in consecutive moments separated by the time step At The algorithm simulates the natural processes in the considered space The increments of the E field components between the time instants and t t At are calculated from the space derivatives of the H components at the instant t 0 5 At Next the increments of the H field components between the time instants 9 5 and tn 1 5 tn 0 5 At are calculated from the space derivatives of the E components at the instant The process of field calculation for a consecutive time instant advanced by Af is called iteration FDTD was first introduced by Yee in 1966 and since then ap
76. ductor in the line s cross section This may happen when the discretization is too coarse and two physically separate conductors merge on the FDTD grid To avoid merging short nodes belonging to two conductors must be separated by at least one non metal node e After terminating the TEM template generation QW Simulator will display in the Simulation log the characteristic impedance of the considered TEM line and its effective permittivity Fig E 2 5 1 1 3 presents example of the upper part of the I O Ports Parameter dialogue when multiTEM option is chosen in the Exciting field box and we have clicked over MultiTEM button This is applicable to multiconductor TEM lines The example is taken from QW 3D UG 2 2 10 In the considered project we have three different metals Multi TIEM option allows defining TEM templates by assigning a specific quasi static potential to each of the conductor as specified in the Conductors potentials box a W O Ports Parameters Conductors potentials Mame Exciting field M edium name Potential inp OOR l igri mutiTEM metal 0 Transmission line metal I O SOURCE Permitivity metal 1 effective No of 10 ports 4 Sige Auto AHTO HO WARNINGS Fig E 2 5 1 1 3 The upper part I O Ports Parameters dialogue box in the case of a Multi TEM port There is one more option of the TEM family It is called planeTEM It is designed for a specific case When we consider a rectangula
77. e able to assist the authors in quick removal of any possible difficulties in software operation E 4 1 Files used by QW Editor created by QW Editor or externally Internal files of QW Editor comprise project files and project independent files To discuss the project independent files let us refer to the directories of installation CD which should be duplicated on the user s computer see Section UG 1 4 Let us take a look at the new system of subdirectories concerning QW Editor e qwbin contains the actual executable file of QW Editor ged exe e envircontains files for setting up the environment o zednqw ini contains various sections which can be modified by the user Example of this file as included on the installation CD has been shown in Section UG 1 4 QW Editor makes an attempt to read this file whenever it is started Although QW Editor will start even if the file is not found some features of QW 3D may not work in such a case e g File Export and Run The sections of zednqw ini file are e tools contains paths to external tools see remarks on installation in Section UG 1 4 FreqRange is a default frequency range for the dialogues of Parameters I O Ports and Parameters Postprocessing lOPortsPar are default Template Parameters DefaultColours are RGB values of background colours for 2D and 3D windows UndoParams specifies the number of recent operations that are stored in memory and thus ca
78. e enforce E plane of the FD TD grid at the level of the bottom and top of the element Nn enforces neutral plane either E plane or H plane of the FD TD grid at the level of the bottom and top of the element Additionally lowercase letter d l or h can be appended to IN option to define classes of AMIGO priorities respectively disabled hard edges lines hard OUT medium fills outside the defined left counter clockwise oriented contour Note that this option is not recommended for a general use WIRE element is a wire line The programmer has to ensure a proper shape of such an element The line describing the wire shape does not need to be closed Inside the frame of the element declared as WIRE there may be a declaration of its diameter as presented below e ENDELEM End of element frame e SETATTR lt which_attribute gt lt attr_value_1 gt lt attr_value_2 gt Sets a property for element allowed only inside the frame of the element element frame where lt which_attribute gt index of attribute to set index 0 AMIGO status lt attr_value_1 gt 1 no change 0 soft default 1 hard edges 2 hard lt attr_value_2 gt 1 no change 0 enabled default 1 disabled QW Editor v 6 5 78 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language DIAMETER lt dia gt Declaration of wire diameter allowed only inside the frame of the element declared as WIRE NEWLINE lt x1 gt
79. e error of the software QW Editor v 6 5 33 QWED PL Chapter E 2 Graphical editor a Reproduce ue xz copy Clear Exec Fig E 2 2 2 9 Dialogue window for Reproduce operation e Join This command concerns putting together intersecting elements Prior to its execution we must declare the intersecting elements as active or passive in the Select element dialogue window We have three options of join operations seen in the Join dialogue window see Fig E 2 2 2 1 o Cut option we cause the active element to make a hole in the passive one Active element will not be changed o Intersect option is used to produce one element of the shape being the common part of the passive and active element filled with the medium of the active one o Glue option is used to merge the elements The resulting element will be filled with the medium of the active one Attention When executing the commands of the Edit and Draw groups we can enter the desired position of the cursor from the keyboard To do this we should press K and use the appearing dialogue box to enter the desired coordinates E 2 2 3 The Draw group of commands The Draw group contains the following commands e Undo and Redo are equivalent to the Edit Undo and Edit Redo commands see Section E 2 2 2 e Element To draw an element we define the shape of its base The element is being introduced on the current level and with the current height To change heigh
80. e generation port is not a subject of symmetry condition either Horizontal or Vertical if a role of the source is assigned to that port during the run with Smn postprocessing it will be excited by a pulse of spectrum 15 lt fK25 GHz with duration of 3 periods of the upper frequency the amplitude equal 1 and delay equal 0 H 1 0 Ports Parameters Excitation Name Waveform Exciting field coaxout TEM pulse of spectrum fH lt f lt f2 v Transmission line NR 2 Frequency 1 0 LOAD Permitivity Symmetry f 15 GHz effective f2 25 GHz No of 1 0 ports 2 ava Auto AUTO H OY Duration 3 jp NO WARNINGS Amplitude Delay ns MultiT EM Cancel Put Fig E 2 5 1 1 1 The upper part I O Ports Parameters dialogue box in the case of a TEM port QW Editor v 6 5 51 QWED PL Chapter E 2 Graphical editor 2 x Name rc Excitation Wavef FE Exciting field iial guideinp zi mm e pulse of spectrum f1 lt F lt f2 v Transmission line NR 1 no excitation delta 1 0 SOURCE sinusoidal Ai pulse of spectrum f lt f2 pulse of spectrum f1 lt F f2 ia TA a Gauss of spectrum f f1 f2 uto NO WARNINGS C TE11 step pulse step with finite rise time dt 1 f2 defined by user text file C_TMO1 multiT EM planeTEM Cancel Set All MultiTEM Fig E 2 5 1 1 2 The upper part I O Ports Parameters dialogue box showing the choice of options of Exciting field a
81. e magnetic losses E E suppress enable electric losses P P suppress enable metal losses BN BD BT narrow decade two decades metal losses bandwidth E 3 7 Moving the elements copying them and controlling their intersections So far we have explained how we can use the UDO language to define shapes However it would be difficult to describe some commonly used shapes this way For example let us imagine a cross junction of two coaxial lines Although the lines are of simple cylindrical shape the analytical description of their intersection would be complicated Moreover there are problems with defining such a junction as a result of logical operations on the two coax lines Note that no single topological operation performed on the volume occupied by dielectric or on the volume occupied by metal produces the desired result We can obtain this result from simple cylindrical shapes only by performing several consecutive operations like joining together the inside connectors joining together the dielectric fillings and then placing the obtained combined connector inside the combined dielectric structure This is how we would proceed to create such a structure in the QW Editor QW ObjectGenerator is prepared to imitate this process following commands stored in the udo file We have a broad choice of commands available here In general we wanted to make it possible to execute all the commands available in the QW Editor A
82. e project does not exceed below 20000 units or above 20000 units in any dimension Note that the above snapping of coordinates has been introduced in purpose to avoid hazards with declaration of shapes In other words we are trying to limit the risk of introduction of unintentional slots or overlapping appearing in the considered structure due to limited accuracy of computer floating point operations on geometrical dimensions E 2 6 Application of QW Editor using library objects In QW 3D version 2 1 QWED has introduced a new system of User Defined Libraries Although the UDO scripts have been used in the earlier versions now they are supposed to be used in a different and much more user friendly way The new structure of libraries has been described in Sections UG 2 8 1 and UG 2 8 2 There are also other examples of the library applications throughout the entire Chapter UG 2 QW Editor v 6 5 69 QWED PL Chapter E 2 Graphical editor More advanced users who wish to build their own libraries are encouraged to study Chapter E 3 in which the syntax of the UDO language has been presented E 2 7 File exporting and starting the simulation from QW Editor E 2 7 1 Export and Run commands Let us take a look at the files in which our example project project_name has been stored To load it to the QW Editor we have read the file project_name pro containing the information about the shape of the structure and the parameters To prepare the use of
83. e the cell size smaller The user is encouraged to press the button nspect to investigate the cause of generating such a small cell The obtained window shows the mesh snapping planes generated by the software They are classified into four groups of priorities Master Hard Soft and Weak The meaning of those priorities is described at the end of this Section Other information provided in the window is assumed to be self explaining e FDTD iterations is a group providing information about the expected duration of the simulation In particular it shows o The number of FDTD iterations needed to obtain the assumed frequency resolution df From the Fourier transform properties resolution df requires simulation time T 1 2 df On the other hand T N dt where N is the number of FDTD iterations and dt is the time step of the FDTD leap frog algorithm The software automatically chooses dt so that it is proportional to the smallest cell size amin to obey the Courant stability criterion Thus both amin and df influence the required number of iterations o Requested physical time of FDTD simulations T ns see the previous paragraph This parameter may be informative especially in problems considering transients of pulses o The value of T expressed as the number of wave travels across the structure assuming that it is filled with air This value may be informative in the case of non resonant structures of relatively big dimensions when we should
84. e when we have problems with using one of those commands most probably it is the result of the cursor being focused in a window other than 2D one defined in XY plane View Draw Edit Setup Info Help Zoom Undo Undo Circuit type Mesh Extents Redo Redo Plane Options Element Edit Point Level Combined Edit Port Axes Bi phased Element Edit Line Grid Snap Bi phased Combined Edit Element Coordinates Wire Edit Object Mesh IOPorts Select Element SPlanes boundaries Select Object NTF box Reproduce Plane wave box Join Get Object Clear Fig E 2 2 1 The menu and submenus of a 2D window Let us look at the 2D window menus shown in Fig E 2 2 1 There are five groups of commands apart from help We will describe them below QW Editor v 6 5 20 QWED PL Chapter E 2 Graphical editor E 2 2 1 The Setup group of commands QW Edit IN AIR OoOo O x view Draw Edit Setup Info Help o O F fl Circuit type ee Plane E Level i Hes Ht Grid Snap bs Coordinates HH e bk E amp SE So Mesh Fig E 2 2 1 1 Setup group of commands of QW Edit menu The Setup group contains the following commands Circuit type It can also be accessed through the Parameters Circuit type path from the main QW Editor window We set here the type of the considered project In a typical application of the package as a three dimensional tool we put 3D Then the Phase shift per period box is inactive it would
85. eck E Plane wave NA 0 eta Folar jo Neck jo Amplitude Delay nz Set All Mest Frew et f jo MuliTeM C ancel Help Put Fig E 2 5 1 4 1 The relevant parts of the I O Ports Parameters dialogue window in the case of a free space excitation by plane wave or Gaussian beam E 2 5 1 5 I O Port parameters in the case of QW V2D ports In E2 1 9 we have discussed the basic QW Editor rules in presentation of QW V2D projects The basic drawing takes place in 2D windows in cylindrical coordinates x p The basic assumptions of the QW V2D simulation result in the following rules of application of ports Transmission lines ports are applicable in a similar way as in the case of QW 3D projects However the mode shapes are restricted to just one row of cells and the template generation problem becomes 1 dimensional A vast majority of practical problems concern the excitation by a dominant waveguide mode or a TEM mode and thus the Exciting field in the Ports parameters dialogue should be chosen to be that of the mode C TEn1 or TEM respectively and the template is automatically generated The generation of modes in arbitrarily filled axisymmetrical structure and with arbitrary angular variation is possible For the users interested in such an option we recommend to try the template generation procedure based on description of QVWV 3D examples or ask the QWED support for more explanations The Mur ABC works in a similar way as in the c
86. ed Refer to Section UG 2 13 2 for examples of application o Analysis of currents induced in wires In this case a Lumped source probe should be placed on the wire In the I O Ports Parameters dialogue the Exciting field for this source should be selected as the E field component along the wire and the Lumped source probe impedance should be set to Rfohmj INF Excitation Waveform will be ignored The FD probing calculations will be performed on the current flowing in the wire H field integrated around the Lumped source probe FD Pavailable This is a new functionality of version 6 0 It invokes calculations of the Fourier transform of excitation waveform of all sources The result will be a square root of time maximum spectral power density at each frequency point when displayed in square scale it will be time maximum spectral power density in Watt FD Pavailable essentially amounts to applying FD probing on source signals and therefore both groups of results are accessed in QW Simulator via the same View FD Probing Results command Refer to Section UG 2 13 3 for examples of application S differential We calculate the S matrix of an N port where N is the number of virtual ports defined in the structure The system can include both transmission line ports and lumped sources probes For each transmission line port the total fields at its respective reference plane are filtered through the modal template and decomposed into incident and re
87. elds If the interaction is high it may cause increased computational errors or even algorithm instability e In the case of Mur ABC the user sets only one parameter the effective permittivity of the medium in which the wave propagates It is used by the software to calculate the correct phase velocity of the wave Incorrect assumption of the effective permittivity increases the level of spurious reflections from the ABC MultiTEM E 1 0 Ports Parameters H 1 0 Ports Parameters Name Hare a Profile abs_top v pml_bot vi l Mur ABC NR 0 Point naci Parabolic v Permitivity l ABSORBING PML Thickness Al effective ee 5 No of 1 0 ports 8 ee 1 Sone NO WARNINGS MukTEM Put Taraniata Adiuianacsd Dararmatar Fig E 2 5 1 2 1 The relevant parts of the I O Ports Parameters dialogue window in the case of absorbing walls E 2 5 1 3 I O Port parameters in the case of lumped sources probes or lumped impedances Lumped sources may serve two tasks When they are placed in free space thy represent radiating dipoles see for example UG 2 11 2 Step 5 When they are placed between two pieces of metal they can serve as a lumped excitation of a structure see the example of wire antenna presented in UG 2 3 4 Example of the I O Ports Parameters dialogue in the case of a lumped source is presented in Fig E 2 5 1 3 1 We can see that the lumped source has a user defined internal impedance as well as the exciting field component N
88. elow the menu described above we have a toolbar Fig E 2 1 7 1 containing icons which are shortcuts to the basic commands File New a Project Draft Modify All L File Load Project Final Modify All E h File Save Ctrl S File Export E File Save as File Export amp Run File UDOPath File Export amp Test Ix oi File Exit File Export Run amp Start 8 GW ww 8 Parameters Amigo File Export Run amp Start Prony E W Parameters Circuit type Ctrl T File Export Options Parameters I O Ports Tools Calculator D B BG Parameters Postprocessing Tools Notepad fe uu Parameters Units Tools Simulator E Parameters Media Tools SAT Viewer j 5 2D Windows Open 2D Tools SAT Filter 3D Windows Open 3D a Tools D XF Converter wi Windows Open ProjectInfo ey Tools UDO Editor he Windows Refresh E Help Contents oa Windows Arrange E Help About Ctrl A E 2 1 8 Displays of the shape of QW 3D projects Example of the main window is presented in Fig E 2 1 8 1 It presents a coax to waveguide transition considered in Wgtocx wgtocx1 pro example thoroughly described in Section UG 2 2 of QW 3D UG The project is visualised in four windows The two on the left are 2D the two on the right are 3D QW Editor v 6 5 17 QWED PL Chapter E 2 Graphical editor Let us note that in the QW Editor we use in parallel two systems of coordinates One is the general 3D system of the axes X Y and Z The other is a local 2D syst
89. em bound to a particular 2D window The variables of this system are U and V The local system can be changed using Setup Plane command For example it can be rotated by a particular angle and in such a case the lines drawn parallel to it will be inclined by this angle with respect to the XY axes of the general 3D system The general coordinate system is marked in the 3D window by three short thick axes coloured red green and blue KGB corresponding to XYZ The position of the cursor in each of the 2D windows expressed in the local coordinates is displayed in the lower part of this window Here we have the U and V components as well as the increments of these components from a chosen last click reference point These incremental components are set to zero after we press the left mouse button To be able to compare the local components with the general components it is sufficient to press the space bar and we can see the window with the position of the point in the XYZ coordinate system Pressing the space bar once again closes the window with XYZ coordinates Note that the content and position of the toolbars can be individually set in each window To show or hide a group of command press the right mouse button to open relevant menu To change the position click over the grey 10 points field of the particular group of commands and drag it to the desired destination H Quick Wave 3D 2DVcoa Editor V6 5w 2006 10 31 H1 wetocx1 File Parameters
90. ent tool acting with a block bitmap tool bmp PAR Object name oname toolex PAR Block length a 12 PAR Block width b 10 PAR Block height h 7 PAR Medium med teflon PAR Tool width ta 4 PAR Tool length tb 5 PAR Tool height th 3 PAR Tool vertical pos tup 4 PAR Tool horizontal pos thp 2 ENDHEADER OPENOBJECT toola ELEMENT z h 0 med block IN NEWLINE x y x a y ADDLINE x a y b ADDLINE x y b CLOSELINE ENDELEM yp yt thp b 3 xp x aq 0 5 ELEMENT z tvp th 0 metal tool IN NEWLINE xp yp xptta yp ADDLINE xp ta yp tb ADDLINE xp ta 0 5 yp tb 2 ADDLINE xp yp tb CLOSELINE QW Editor v 6 5 Example A tool interacting with a block tool udo UDO script for QW 3D UDO script for QW V2D comment Tool acting with a block V2D version bitmap tool bmp PAR Block length a 12 PAR Block width b 10 PAR Medium med teflon PAR Tool width ta 4 PAR Tool length tb 5 PAR Tool horizontal pos thp 2 ENDHEADER OPENOBJECT toola ELEMENT z 1 0 med block IN NEWLINE x y x a y ADDLINE x a y b ADDLINE x y b CLOSELINE ENDELEM yp yt thp b 3 xp x a 0 5 ELEMENT z 1 0 metal tool IN NEWLINE xp yp xp ta yp ADDLINE xp ta yp tb ADDLINE xp ta 0 5 yp tb 2 ADDLINE xp yp tb CLOSELINE ENDELEM REDRAW 3000 MARK ELEM tool SET SHIFTM 0 b 2 5 0 QWED PL Chapter E 3 S
91. ent on the list or by a single click over the element and a click over the Select box The dialogue window disappears and we are back in the 2D window on a correct level Now it is sufficient to click over the element to start moving it to a different place Sometimes we want to change a position of just one point of the element In this case after selecting the element we should click over the Edit Point icon in the 2D window toolbar and choose the point to be moved o The operation of selecting an element is also convenient when we want to edit it When the element is selected it is sufficient to press the right mouse button to enter the Element change dialogue window Fig E 2 2 2 5 bottom left shows this dialogue for a QVWV V2D antenna element We can change numerically shift the element s position in the case of QVV 3D the shift would be possible also along Z axis We can also modify the medium of which it is composed through Edit button and the colour used for its display The HV Grid button of the Element change dialogue becomes active only for metal elements of zero height and then can be used to convert thin metal layers to horizontal wire grids see Section E 2 2 7 for more details Note that invoking Edit Element command through the Select element is comfortable especially when we have several elements situated in one plane very close to one another or even interposing and it is difficult to pick one of them up by mouse operation on the
92. er left window in Fig E 2 1 9 1 Thus that picture concerns half of the structure long section with the axis of symmetry situated at the bottom of the picture and represented by a thick broken line The third dimension with respect to p is always equal to 2z and in the 2D windows is symbolically represented by the unitary height of the single layer of FDTD cells That unitary size does not carry any information but formally can be represented in a 2D window in p p or x p coordinates see the lower left window of Fig E 2 1 9 1 In the 3D windows QW Editor tries to reproduce the actual 3D shape of the axisymmetrical structure Although in reality the p coordinate always spans over the entire 2z angle as shown in the upper right window of Fig E 2 1 9 1 it can be visualised also with assumption of the user defined span of see the lower right window Such a visualisation shows better the details of the cross section of the structure i Quick Wave 3D 2DVcoa Editor V6 5w 2006 10 31 H1 corhorn1 File Parameters Windows Project Tools Help DEADS x e ZEH Zomm i fm DF bp FF PTS x BOW aay HgS T QW Edit IN AIR O x Gow view view Draw Edit Setup Info Help View OH 2 EON e wY EASES N SO Agr ge ai MT FETAN AA bes ep tS eS oi RN ae REESE PST il EHEN Se ifn Net Tr eee TD H LR PR TTT EE T l UU eb tbe LELA i 4 H H tt ui n AE TONTIT ONTOTTA bad w ay A i _ i a _ ve aa he ne
93. erent mode template Transmission line ports are defined for S parameter extraction To allow application of the differential method they must be accompanied by reference planes at a distance of minimum 3 FDTD cells from the port The port must be defined on a segment of transmission line such that its geometry and material filling between the port plane and the reference plane and three cells beyond the reference plane do not change Each port is labelled as a source or a load This marks its function when the S matrix are calculated with excitation from just one port Sx postprocessing In the case of Sim postprocessing QW Simulator performs several runs with consecutive ports acting as sources The class of transmission line ports may be divided into four subclasses TEM multiTEM planeTEM and waveguides We will start with a TEM port Fig E 2 5 1 1 1 presents the upper the only relevant part of the I O Ports Parameters dialogue in the case of coaxout port of the wgtocx1 pro example discussed in QW 3D User Guide The choice of TEM is marked in the Exciting field box Scanning the dialogue from the left we can see that port name is coaxout it has been labelled as a I O LOAD it will be referred as No 2 in S matrix calculations Auto checked means that during the port operation as a load QW Simulator will take the effective permittivity needed to optimise the absorbing boundary condition from the results of TEM templat
94. esh Axes and Grid correspond to the Visible fields in Setup Mesh and Setup Axes and to the Grid box in Setup Grid Snap respectively When Show Lines in plane is selected only the elements having bottom at the current level will be displayed o Thick lines allows choosing whether Marked Active and Passive elements be displayed with standard or thicker contours o Apply Cancel and OK buttons have standard Windows meaning o Background colour allows customising the background colour for the circuits defined in air and in metal separately E 2 2 5 The Info and Help groups of commands The Info group contains the following commands e Mesh Mesh refers to the set of FDTD cells These cells of cubicoidal or cubicoidal cut by a plane shape have the basic size defined through the command Setup Mesh However the actual cell size may be modified downwards by the software to fill the area between mesh snapping planes with an integer number of cells Mesh snapping planes are either introduced explicitly by the user via Draw SPlanes boundaries command or forced automatically by the QW Editor for example at horizontal boundaries of metal elements The Info Mesh command permits to see the list of all mesh snapping planes on the left of the box of Fig E 2 2 1 10 and the minimum distance between the neighbouring planes on the right of the box This permits to spot the planes very close to one another Such planes would produce very small FDTD
95. eting the N simulations with excitation from N consecutive ports QW 3D assembles the complete S matrix correcting all the S matrix elements for imperfect absorbing at all port Thus the final results of S calculation may be somewhat different from the intermediate results displayed during calculation o In the multistmulator regime the software opens N instances of the QW Simulator with a different exciting port in each of them An apparent disadvantage of this regime resides in the increased memory requirements However its important advantage is the possibility of the on line monitoring of the full corrected S matrix calculated for the current number of FDTD iterations This regime works on single processor computers its operation on multiprocessor computers is allowed only if the QW MultiSim option has been acquired by the user o The multithread regime is available only to the users who have acquired the QW MultiSim option In such a case the software runs different instances on different processors which decisively saves the computing time Like in the multisimulator regime increased memory is required Users interested in this option are referred to the manual of QW MultiSim available on the installation CD Attention Only in the circuit which is not declared to be reciprocal the reflection coefficient is calculated independently of the outputs In other cases it is corrected for the reflection on the output ports In those case
96. f we select Smn postprocessing Instead for the N port circuit QW Editor will export N different pa3 files instructing QWV Simulator to apply excitation to the N consecutive ports Each of these files will be called by the name of the reference plane corresponding to the excited port All the above operations are performed upon execution of the File Export command After the export has been performed we can leave the QW Editor invoke the QW Simulator and perform the simulation This kind of operation may be advantageous on computers with small memory It is also possible to run the simulations directly from the QWV Editor by invoking the command File Export amp Run or the shortcut flash icon corresponding to it However during such a mode of Operation more memory will be occupied by the program itself and less of it left for storing variables of the electromagnetic modelling In this section we have signalled that the QW Editor produced several types of files which are needed by the QW Simulator More systematic description of these files and other files used by the QW 3D package can be found in Chapters E 4 E 2 7 2 How to assure the proper mesh generation The process of meshing consists of generating a set of FD TD cells describing the considered structure As it has been mentioned in Section UG 2 1 half cells form sublayers in XY plane with one layer of the FD TD cells composed of two sub layers Each of the half cells of QVWV 3D conf
97. flected waves via the differential method Reference impedances for S parameter extraction are the actual frequency dependent wave impedances of respective transmission lines These impedances can be viewed in QW Simulator by Setup Switch Extended Results option of View S Results command At a lumped source probe the S differential system operates similarly as the FD probing Thus for meaningful results each lumped source probe should be placed between two metal elements separated by one FDTD cell The S differential system considers the port voltage selected E field integrated along the FDTD cell and the current flowing into the embedding circuit without the current component flowing into the FDTD cell Reference impedance is taken as resistance of the lumped source probe unless this resistance is zero in which case 50 ohm is taken Options of the S differential postprocessing are described further in this Section For detailed introduction to this postprocessing refer to Section UG 2 2 1 and to other subsections of Section UG 2 2 for its examples of application to various types of transmission lines QW Editor v 6 5 60 QWED PL Chapter E 2 Graphical editor e S direct We also calculate the S matrix but without applying the differential decomposition In version 6 5 of QW 3D this postprocessing is unavailable e Eigen values This option is activating the optional frequency domain eigenvalue solver Interested users are encou
98. for all active postprocessings Default medium Metal C 3D of 2D eoa Angular variation a C Air C IDP f 2005 1 C on Frequency Considered range trom H E to f2 js with resolution df 0 04 GHz W Change accordingly 10 ports and postprocessings postprocessing step will be df 5 Mesh control f AMIGO Manual Minimum f 2 cells per wavelength corresponding to cell size amas i 56551 mm Avoid cells below Imin E mm fal Curent number of cells 1 J20 Curent smallest cell size amin 0 3571 4 mm Inspect FOTO iterations Present settings of df and amin require f 8 O00 Iterations Ik corresponds to f 2 5 ne real time or fi O18 4 wave travels across the structure suspend simulation after the above number of iteration a Fig E 2 1 2 1 1 AMIGO dialogue window Mesh Control group allows to switch on of automatic meshing performed by AMIGO It contains two boxes with basic parameters to be set by the user o The first of them is used to set the minimum number of cells per wavelength AMIGO will take this number as a guideline to prepare the meshing in such a way that in all materials used in the project the wavelength to cell size ratio does not drop below this value In typical applications this number should be set to 10 15 but some precise calculations may require refined meshing with 20 cells per wavelength or more o The second number Imin in the box avoid cells below gives a s
99. forming a mirror reflection of all the marked elements or objects with respect to the plane x xmirror MIRRORY ymirror Performing a mirror reflection of all the marked elements or objects with respect to the plane y ymirror MIRRORZ zmirror Performing a mirror reflection of all the marked elements or objects with respect to the plane z zmirror MODE gormo mag ses pormo SSCS frequencies_ string Defines NTF frequencies OPENF ilenamey Open a disk text fle foreaging OPENOBJECT Start of object frame escry text var name def Parameter definition Val PERIODIC activity _x activity y Defines features for periodic circuits activity _z beta x beta y beta z PLWAVE phi theta polarisation Defines plane wave data PLWBEAM beam type neck origin X Defines beam data neck origin Y neck origin Z neck dia angle of variation PORT level height type activity Start of port frame name reference PORTEXC pointlz point2z Moving the excitation points to arbitrary z level PORTPAR size size activity activity Sets mesh snapping and mesh enforcing port_plane port_circumf properties of the port PORTPAR2 subcircuits_margin Sets subcircuits_margin property of the port active walls dummy dummy PORTPOSTP argl arg2 Refers to lumped source probe and determines in which postprocessing it is to be included PROFILE type par_a par_b file name Defines PML profile PRONY take every below Enables P
100. g a particular udo file the interpreter tries to locate its bitmap file of given name in the following sequence of steps 1 by standard File Open command on given name in practice works if full name is given 2 udo directory name 3 in consecutive directories set by the user as UDO Paths name 4 in elib bitmaps directory name If all four steps are unsuccessful it terminates with a warning message listing explicitly all paths that have been tried QW Editor v 6 5 97 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language txt and other files opened by OPENF command and read from by READF The interpreter tries 1 project directory name 2 elib directory name 3 by standard File Open command on given name in practice works if full name is given If unsuccessful it terminates with an error message lop files used by GETIOPAR command The interpreter tries 1 project directory name 2 by standard File Open command on given name in practice works if full name is given If unsuccessful it terminates with a warning message E 3 11 Optimising with UDO Parametric representation of variables in UDO objects combined with command line operation of QW Editor opens way to automatic circuit design by running QW 3D within an external optimisation loop Interested users may either apply an optional QWV OptimiserPlus module or try to couple QW 3D with their own optimising procedu
101. g with different resolution Arrange arranges the windows on the screen according to the following rules one 2D window if open is moved to upper left corner e another 2D window if open is placed in lower left corner one 3D window wireframe view if open is moved to upper right corner one 3D window solid view if open is moved to lower right corner e windows too big to fit on the screen are reduced in size e windows pushed out of the screen are pulled back E 2 1 4 Project group of commands Project group contains two commands needed for operation with biphased UDO objects 1 Quick Wave 3D 2D coa Editor File Parameters Windows Project Tools Help 2D Final Modify Al Fig E 2 1 4 1 Project group of commands of QW Editor menu o Draft Modify All redraws all UDOs in draft phase o Final Modify All redraws all UDOs in final phase E 2 1 5 Tools group of commands Tools group provides access to external applications or format converters They are QW Editor v 6 5 13 QWED PL Chapter E 2 Graphical editor a Quick Wave 3D 2D coa Editor File Parameters Windows Project Tools Help IO E a Ly x a Calculator Motepad Simulator A SAT Viewer am 5AT Filter DAF Converter Ee UDO Editor A My Tools b AL Set Tools Fig E 2 1 5 1 Tools group of commands of QW Editor menu o Calculator which is supposed to be a standard calculator available in Windows
102. girding snapping and displayed as local coordinates R F instead of U V Drawing and mesh generation are always performed in rectangular coordinates QW Editor v 6 5 24 QWED PL Chapter E 2 Graphical editor 2 x Coordinates type f Rectangular Polar _Cancel Coordinates box space bar ae Fig E 2 2 1 8 Coordinates Options dialogue window e Mesh Here we define the parameters of the FDTD mesh see Fig E 2 2 1 9 o In the right part of the dialogue box we state in which part of the circuit the FDTD mesh is to be created Typically we want to mesh the entire volume occupied by our structure Then we shall keep in the section Adjust to the default setting Objects checked on However sometimes we may wish to analyse only a part of the structure for example to speed up the simulation by exploiting spatial symmetry or to analyse only one selected discontinuity with refined meshing In such a case we should uncheck the Objects box and set the mesh boundaries explicitly The UV axis to XY box can be used as one shortcut introducing the X and Y mesh limits equal to the 2D Axes Setting of the active 2D window which is itself accessible via Setup Axes command The other shortcut is Limits to XYZ which introduces the X Y and Z mesh limits equal to the outermost positions of all the defined elements objects and ports Please make sure that all the declared ports are situated inside the meshed part Otherwise it w
103. guage Three variables denoting the coordinates of the object origin x y z are predefined and can be set modified in a dialogue box Arithmetic expressions and standard functions are similar to those used in C language It is possible to read numerical variables form a file To do that we need first to open such a file using the instruction OPENF lt file name gt Then READF will be returning the consecutive number read from the file READF can be placed at the right side of the equation e g a READF as well as inside an equation e g a 2 sin READF b Opening of a new file automatically closes the file previously opened if any Numbers and variables All the parameters of Elements Ports and the coordinates used in NEWLINE ADDLINE must belong to one of the following categories Numbers or strings where a string is expected as a parameter Object parameters as declared in PAR declaration Variables which are declared by their first appearance at the left side of a substitution equation with a number or expression at the right side like for example k 5 or k 2 n 1 The type of the variable is assigned automatically by the UDO interpreter Values of READF function Expressions composed of items belonging to the above categories and the following operators and math functions Operators increment decrement change sign addition subtraction F multiplication division power
104. h a process if unrestrained would result in generation of some very small FDTD cells This would cause a radical drop in the smallest cell size amin and as a consequence in the basic time step dt This in turn would cause a drastic increase of computing time QW Editor v 6 5 11 QWED PL Chapter E 2 Graphical editor To avoid such an effect AMIGO sets priorities to the mesh snapping planes and in case of conflicts eliminates those less important in order to try to keep the cell size above declared value of Imin There are four classes of priorities of mesh snapping planes weak generated by AMIGO and eliminated in the first place when the condition for Imin cannot be met soft generated by AMIGO and eliminated in the second place when the conditions for Imin cannot be met hard generated by AMIGO upon the user s declaration of a particular element as hard or of hard edges They are not automatically eliminated by AMIGO when the condition for Imin cannot be met Instead they can be reviewed by the user using Inspect command in the Mesh Control group of AMIGO dialogue and possibly deleted upon the user s specific request Hard planes are mostly used for metal edges like for example edges of a strip of a microstrip line At metal edges the fields are highly singular When a metal edge is aligned with limits of FDTD cells QW 3D automatically introduces special mathematical models of field singularities to enhance the
105. hanged e Shift allows to move the port by a certain distance in the direction of each of the three axes Note that in the case of reference planes shift will only be allowed along the transmission line E 2 5 Parameters of wave simulation E 2 5 1 Input Output Port parameters In the QW Editor we do not only prepare the shape of the considered structure and define the FDTD mesh but we also set several important parameters of the FDTD simulation Among them are the I O Ports Parameters The I O Ports Parameters dialogue box can be accessed by the path Parameters I O Ports The I O Ports Parameters dialogue changes depending on the type of port In the next five subsections we will discuss the shape of the dialogue for different types applicable in QWV 3D software In subsection E 2 5 1 5 we will concentrate on QW V2D applications of ports QW Editor v 6 5 50 QWED PL Chapter E 2 Graphical editor E 2 5 1 1 I O Port Parameters in the case of transmission line ports Transmission line ports have the following features Each of them is characterised by its geometry as described by the user in the shape editor and by a particular propagating mode Port parameters should allow QW Simulator to generate the field distribution of the desired mode in a normalised form Such a distribution is called the mode template In general one geometrical port may be represented by several electromagnetic ports each of them associated with a diff
106. hecked if only half of the waveguide has been drawn with respect to m or n index utilising symmetry of the circuit This instructs the software to take double port dimension along m n for calculating cutoff frequency and thus effective permittivity for the mn mode QW Editor v 6 5 54 QWED PL Chapter E 2 Graphical editor e Effective permittivity is calculated for a previously set matching frequency If the user subsequently changes the matching frequency effective permittivity is not automatically recalculated The simplest way to recalculate it is to re select the desired mode e For other modes inhomogeneous filling or quasi TEM lines at high frequencies the user should select the mode to be Arbitrary and proceed according to the guidelines formulated in the User Guide e The software will try to generate template at the matching frequency within a specified margin Template mode searching range should include this frequency A warning will be issued 1f the matching frequency cannot be found e Excitation field component this is the component used for mode template generation It should be set in accordance with the expected template mode distribution as described in Sections UG 2 2 4 UG 2 2 6 e Number of iterations for template generation We have three numbers here but they are mutually dependent as described in Section S 2 2 A typical value sufficient for obtaining a steady state with sinusoidal excitation in most appl
107. hen the options snap mesh to port plane or snap mesh to port circumference are checked see Fig E 2 4 1 1 introduced automatically by the software at the level of bottom and cover of each element Note that only mesh snapping planes perpendicular to the Z axis can be created in this way If the default medium is Metal all these planes will be of electric QW Editor v 6 5 26 QWED PL Chapter E 2 Graphical editor type If the default medium is air metal elements will force mesh snapping planes of electric type and non metal elements of neutral type introduced automatically by Amigo if active in order to optimise meshing o The information visible in the Mesh Splanes info dialogue of Fig E 2 2 1 10 includes Location of each mesh snapping planes Type el denotes electric or short which forces a plane of tangential electric fields and thus contains the cell sides ma denotes magnetic or open which forces a plane of tangential magnetic fields and thus bisects the cells ne denotes neutral which may coincide with either tangential electric or tangential magnetic fields Cell size forced in the negative and positive directions from the special plane If the user has explicitly defined the forced cell size when drawing or editing this particular special plane see Section E 2 4 2 for details this value will be shown without brackets and supersede all defaults However if the user has not made such an e
108. hould be positive OPENOBJECT oname ELEMENT z h1 0 med cubic1 IN NEWLINE x a 2 y b 2 x a 2 y b 2 ADDLINE x a 2 y b 2 ADDLINE x a 2 y b 2 CLOSELINE ENDELEM ELEMENT z h1 0 5 med prismb INe NEWLINE x a 2 y b 2 x a 2 y b 2 ADDLINE x a 2 y b 2 ADDLINE x a 2 y b 2 CLOSELINE ENDELEM ELEMENT z h1 h2 0 6 med prismt INe NEWLINE x sr a 2 y sr b 2 x sr a 2 y sr b 2 ADDLINE x tsr a 2 ytsr b 2 ADDLINE x sr a 2 ytsr b 2 CLOSELINE ENDELEM ELEMENT z h1 h2 h3 0 med cubic3 INn NEWLINE x sr a 2 y sr b 2 x sr a 2 y sr b 2 ADD Y sr b ADDX sr a CLOSELINE ENDELEM CLOSEOB J QW Editor v 6 5 76 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language Please draw the above UDO in an empty project to see that it produces two cuboids connected by a prism Thus we have three elements declared in the UDO script Two of them are simple elements and the connecting prism is a combined element as defined in Section UG 2 1 We will discuss here the basics of introduction of elements in UDO scripts A simple element starts with a key word ELEMENT and ends with a key word ENDELEM There are six parameters to be defined in the ELEMENTV as specified in the syntax description at the end of this section Note that first two parameters define the position of the bottom of the element and its height The subsequent instructions are for drawing a contou
109. ications is about 10000 However the user is advised to observe the field distribution during the sinusoidal stage of the template generating process see Section S 2 2 to find out if for his applications this number should be cut down to save computing time or increased to get better accuracy of the final mode template Summarising the discussion of arbitrary templates let us stress that QW 3D is very flexible in terms of choice of the mode in arbitrarily shaped and inhomogeneous transmission lines forming the ports of the structure The price for this flexibility is the need to set several parameters enabling the software to find the mode of interest In general this is difficult to avoid and the following rules of thumb for setting effective permittivity may be useful e any guide any mode at cut off effective permittivity 0 e empty cylindrical waveguide filled with air effective permittivity 1 cut off frequency of the mode operating frequency i e cylindrical waveguide filled with dielectric of effective permittivity 1 cut off frequency of the mode operating frequency a e cylindrical waveguide filled with material of and uw effective permittivity u 1 cut off frequency of the mode operating frequency an e inhomogeneous quasi TEM line including dielectrics of lt 2 lt lt n lt effective permittivity lt n E 2 5 1 2 I O Port parameters in the case of absorbing walls
110. ids A grid of wires parallel to the XY plane can be created by drawing a metal element of zero height of an arbitrary shape in a standard way see Section E 2 2 3 The Element Change dialogue for such elements has now been supplemented with Advanced parameters part and is shown below Tab E 2 2 7 1 It allows to choose between a metal patch or a wire grid and to specify orientation and diameter of wires Note that o Ifonly H or V orientation box is checked the X or Y oriented wires are created respectively The last wire in the positive X or Y direction respectively is not created o If both H and V orientation boxes are checked a 2D grid of the X and Y oriented wires is created Stair case approximation of the shape is applied The last wires in the positive X and Y directions are not created o If none of the orientation boxes is checked default a thin metal patch is conformal modelled as in the previous versions of the software E 2 3 The 3D windows Bow View C Free Rotation AmE Mew GE Displacernent zzl 2 BA Switch eee Translate Save b g ore See Colour egy Window Zoom Fill Up Down Zoom Undo Light Dump Pixmap Hide Forts amp Boxes V2D View Options Ctr 3 Reset To Plane E Initial view a tx H Smet i ae SE t tz Enable Animation Fig E 2 3 1 View group of commands of 3D QW View menu The 3D windows are of QW View type They allow project visualisatio
111. ike for example in antenna applications you must change it to air It has been noted that a wrong default medium setting is a common user generated error in QW 3D operation Thus please be careful with it o Regardless of the choice of the default medium the default external boundaries of the FDTD mesh are assumed to be made of Metal To assign to them different properties we must do so explicitly by defining them as I O ports or Special planes amp boundaries o We also have five suppress options for suppressing dielectric magnetic or metal losses singularity corrections and SAR analysis The last two options are also accessible as Export options from the main QW Editor window see Section E 2 1 Suppressing the losses saves memory and computing time Thus it is very convenient when we want to obtain faster preliminary simulation results without laborious modification of the entire project o The last group of circuit type choices regards the bandwidth for rigorous consideration of frequency dependent skin effect in lossy metals It has to be pointed out that although the description of losses in metals by finite conductivity is essentially the same as that of lossy dielectrics the level of conductivity makes a very significant difference Due to very high conductivity the wavelength becomes so short that it is practically impossible to mesh the lossy metal volume Thus instead in QW 3D we virtually attach lossy elements to the magnetic field
112. ilable power by A For more information QW Editor v 6 5 52 QWED PL Chapter E 2 Graphical editor about the normalisation needed to read the absolute values of fields and power please refer to Section S 2 7 e Delay is expressed in ns In the case of sinusoidal excitation it is directly related to the phase shift which may be interesting in some applications Note also eight buttons used to scroll the list of ports Next Previous to copy the parameters to all other ports Set All read the set of parameters to a disc file Get or write it to a file Put get help Help and leave the dialogue OK Cancel Let us briefly explain how the TEM port will be generated by QW Simulator e In the first phase the software will search for a conductor Note that every I O port has a distinguished point which is automatically set in the centre of the port but can be moved by the user with the Edit Point command If this point is within a conductor this particular conductor will be selected as a hot one Otherwise the choice of the conductor will not be controlled by the user and a warning will appear in QW Simulator e Inthe second phase QW Simulator will set the potential of the selected conductor to unity and of all other conductors to zero Then it will perform quasistatic finite difference analysis generating the electrostatic and magnetostatic fields Note that QW Simulator will stop with an assert if it finds only one con
113. ilable space not occupied by other elements Note that the recommended way of software operation is to always use the medium inside option The medium outside option is necessary only in one special case making holes in metal layers of zero thickness o Put UDO command designed to save an element on disk as a UDO object o The type of element is displayed here only as an additional information to the user o Note that when we are in the Edit Element mode the cursor changes to a square one To return to the normal mode arrow cursor we must either press E on the keyboard or press the right mouse button and then EscEdit It is important for the user to develop a habit of leaving the edit mode immediately after the edit operation has been performed The operation of other commands while in the edit mode can lead to unwanted changes in the project o Itis possible to Mark one or more elements The marked elements form a group which can be moved or reproduced using the Edit Reproduce command Edit Object This command allows to move the selected object delete it or change its parameters When this command is invoked the software looks for the object closest to the cursor and having the base at the same level as the cursor If we are not sure about the position of the base of the object we should use the Edit Select Object command In the case of external objects we can use QW Editor v 6 5 30 QWED PL Chapter E 2 Graphical editor the comman
114. ilarly to the NTF box case we suggest alternative and more convenient way of introducing the plane wave box by using special plane wave box generating UDOs available in the library elib boxes e Get This command is used to read from disk previously saved elements or objects o Element It is not operational in version 6 5 o Object It is not operational in version 6 5 o Libltem is used to read an external object from the object library e Object This command permits to create internal objects Since an object is a composition of elements there is sometimes a need to combine some elements into an object to be able to move them together All the elements drawn between the command Open and Close or Next will be assigned to the object The following commands are available o Open for opening a new internal object o Next for closing the current object and opening a next one o Close for closing the object the list of elements forming it QW Editor v 6 5 36 QWED PL Chapter E 2 Graphical editor e Clear This command clears entirely the current project leaving the space in the QW Editor for a new project However note that the new project inherits the environment of the old project number of windows their size etc That is why when we want to prepare a new project it is convenient to open an old one dealing with a structure of a similar shape execute Draw Clear and change the name using File Save as E 2 2 4 The View
115. ill be impossible to perform the simulations Mesh boundaries Jw Objects UNM axis to sr Limits to xy Edges force linear mesh wv Visible Amigo mesh control Fen On Edit S planes info Apply Cancel OF Zi Fig E 2 2 1 9 Setup Mesh dialogue window o Inthe left part of the dialogue box we can set the maximum FDTD cell sizes along the axes X Y and Z when we decide not to use Amigo option The Xto YZ box copies the x step into the y and z ones Note that the QW Editor will try to put an integer number of cells between each QW Editor v 6 5 25 QWED PL Chapter E 2 Graphical editor pair of the neighbouring mesh snapping planes It will assume as a precondition that any dimension of the cell cannot exceed the maximum size defined here Thus the maximum cell size Should be chosen very carefully It will play a crucial role in finding a reasonable balance between the conflicting requirements for high accuracy and reasonable computing time taking also into account the limits of the computer memory o Presentation visible permits to display or hide the meshing Pen can be used to modify the width and colour for mesh lines o Edges force linear mesh is an advanced option for gradual change of the meshing To fully understand how it works let us summarise some important pieces of information First of all edges understood as outermost boundaries of the circuit are implicit li
116. ing modification of the medium e Insert to clear the current medium display waiting for a new one to be introduced e Del to delete the current medium e Next to pick up next medium from the active library list Another group of commands concerns operation on libraries In the lower part of the dialogue window we have three commands e New for creating a new library e Load for loading another library from a disk as an active library e Save for saving the active library Finally we can see the Pen and Brush commands which are used to assign colours to media They affect the QW Editor and QW Simulator displays as follows e When an element made of a certain medium is drawn manually Pen assigned to the medium determines the colour for displaying this element However subsequent changes of the medium assigned to this element are not automatically reflected in the changes of colour e When external object is drawn in QW Editor via the Draw Get LibItem command or equivalently the ml icon Pen assigned to the medium determines the colour for displaying elements composed of this medium and included in the external object e When TestMesh operation is performed in QW Simulator each homogeneous subregion is displayed as determined by Brush of the medium and meshing over this subregion is drawn in Pen One of typical operations performed in the Parameters Media dialogue window is adding a particular medium to the project To do this we se
117. ing output data S parameters radiation pattern etc and modifying frequency range of operation see Section E 2 5 2 o Media allows defining and modifying project materials see Section E 2 5 3 o Units allows selecting units for drawing the structure see Section E 2 5 4 E 2 1 2 1 AMIGO Automatic Meshing Intelligent Generation Option AMIGO is a feature introduced in version 6 0 It serves two purposes Firstly it optimises the meshing so as to provide requested wavelength resolution in all media while avoiding small cells Secondly it allows fast setting of frequency ranges for all ports as well as S parameter and FD Probing postprocessings Additionally it shows useful information about details of structure definition that cannot be modelled within requested mesh constraints time step forced by the current mesh expected duration of the analysis and allows setting automatic stop criteria We hope that AMIGO will be enjoyed and much used by both experienced and novice users That is why we are placing its basic description at the beginning of the QWV Editor Reference Guide Most of the examples of application of QW 3D had been prepared before AMIGO was developed That is why the User Guide Sections UG 2 2 to UG 2 15 or Sections V2D 2 1 2 3 contain examples defined and meshed without AMIGO Section UG 2 16 or V2D 2 4 describes an example with AMIGO meshing We suggest the following learning path of AMIGO applications read Section
118. ith parameters This feature is prepared for use with optimisers of 3D structures Starting with version 6 0 QWED offers its own QW OptimiserPlus integrated with QW Simulator The old external QVV Optimiser also remains operational However interested users may also try to couple QW 3D with their own optimising procedures The following options are possible e pproject_name Starts the QWV Editor loading the specified project e i Enforces iconised operation of QW Editor e e Instructs the QW Editor to export the project e q Quits the QW Editor reasonably this should be preceded by export e m Instructs the QW Editor to perform the Select Object Modify operations on the object which has the same name as project For reasonable application the corresponding udo file describing this object or some other udo and txt files called from within this file should be previously modified by the user optimiser e onumber_of_iterations Instructs the QVV Editor to further instruct the QVWV Simulator to run the analysis for a specified number of iterations The QW Editor will comply by exporting modified files modifications regarding RunIter instead of typical Run tasks specified format of files for saving the results QW Editor v 6 5 72 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language E 3 Syntax of the User Defined Object UDO language E 3 1 What is the User Defined Object There are three basic adv
119. keywords 105 library objects 69 lumped impedanc 57 lumped probes 56 lumped sources 56 media library 63 77 105 media types Dielectric anisotropic 64 Dielectric dispersive 64 65 Dielectric isotropic 64 Ferrite 64 Metalic 64 Metamaterial 65 PEC 64 NTF background 63 NTF boundary 36 NTF box 36 61 86 NTF frequencies 61 optimisation 73 98 optimiser 98 options S differential 60 S direct 61 Cut 34 Decade 22 DXF Converter 14 15 Edges force linear mesh 26 Eigen values 61 FD Monitors 61 FD Pavailable 60 FD probing 59 Glue 34 Intersect 34 My Tools 14 Narrow 22 Near to Far 61 Prony method 62 QW MultiSim 62 SAT Filter 14 15 SAT Viewer 14 15 Set Tools 14 Shift amp Rotate 33 Sk1 at reference planes 61 62 Smn at reference planes 62 suppress 22 Test Mesh 72 Two Decades 22 UDO Editor 14 Parameters group of commands 8 PEC 64 Perfect Electric Conductor 64 PML 47 polar coordinates 24 power 5 6 52 81 103 power balance 6 QWED PL Chapter E 5 Index power radiated 6 Project group of commands 13 project media 63 68 project media list 68 project tasker file 70 project units 35 41 projects emptyex pro 94 wetocx pro 31 48 70 Prony method 62 Q factor 6 46 QProny 6 62 QW 3D 5 55 63 73 104 QW BHM 8 64 QW Editor 5 7 8 18 25 27 28 47 50 68 69 70 71 72 73 86 97 104 105 QW Editor menu 7 QW Editor toolbar 17 QW Objec
120. l and dielectric In the case of complicated geometries the mesh generator may initially create cells filled with three or more media We shall call them multiple filled cells Multiple filled cells will be simplified according to the following rules e If the QW Editor finds a cell shared by a metal and two different dielectrics it assumes that the cell is shared between the metal and the dielectric occupying larger part of the cell replacing with it also the other dielectric e Ifthe QW Editor finds a cell shared by three different dielectrics it assumes that the cell is shared between the two dielectrics occupying larger parts and neglects the presence of the third dielectric e In the case of cells occupied by more than three media the QW Editor will assume that the cell is shared between two media occupying two largest parts QW Editor v 6 5 71 QWED PL Chapter E 2 Graphical editor These simplification rules are still under intensive tests Thus temporarily the user is encouraged to use Test Mesh option in QW Simulator to verify the mesh created in regions of complicated geometry In general since the QW Simulator treats more accurately cells filled with one or two media it is recommended to avoid multiple filled cells by defining mesh snapping planes passing through sensitive junction points Meshing hazards along the Z axis Let us recall that at the level of bottom and cover of each element the software automatically cre
121. lect a medium from the active library and press gt button to move it to the project list Sometimes we wish to update some media involved in the project without modifying the libraries To start such an operation we should press lt lt lt button We see that the whole list of project media has replaced the current active library on the left hand side of the dialogue window At the same time the window header has changed indicating that now instead of the active library we are dealing with the project media list We can modify delete add media on that list After the operation is over we should move the updated list back to the right hand side of the window We can see that the button gt has changed to gt gt gt This means that now by pressing this button we will move to the project media list not just one item but the entire updated list The gt gt gt operation includes saving of the updated project media list QW Editor v 6 5 68 QWED PL Chapter E 2 Graphical editor E 2 5 4 Units All the dimensions in the project are defined in the units chosen by the user via the Parameters Units dialogue There are four choices metres millimetres microns nanometres inches o 6 mils Note that the selected units will be applied e for user interface purposes in all dialogues of QW Editor and also QW Simulator s dialogue for virtual shift of reference ports for S parameter extraction Section S 4
122. llows definition of quasi arrays For example we can introduce a set of variables a a2 a3 using expressions a i where i is an index variable However to avoid confusion between a string ai and a variable ai the following rules need to be respected o Let us assume that the index variable i has already been declared and we want to declare a set of variables ai In such a case we should use the instruction a i Note that the parenthesis is indispensable here o When the variable a i is already defined and we want to apply it with a particular value of the index we simply write a1 a2 etc with a general index i we need to use the function VAR a i Let us consider the following modification of threeel udo described in Section E 3 3 comment modified example of three elements bitmap threeel0 bmp PAR name oname 3elm PAR length a 6 PAR width b 5 PAR shape ratio top bottom sr 0 5 PAR medium med air PAR disk file df c temp points txt ENDHEADER TEST a gt 0 amp amp b gt 0 Dimensions should be positive OPENF df h1 READF h2 READF h3 READF TEST h1 gt 0 amp amp h2 gt 0 amp amp h3 gt 0 Heights should be positive continuation like in the original threeel udo If the file points txt contains the consecutive numbers 5 7 3 the result of drawing the modified UDO will be the same as with the original one Note also that QW Edit
123. lt sig gt lt msig gt Defines NTF background dielectric QW Editor v 6 5 89 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language e ALLOWBHM Enables BHM module e ALLOWHF Enables Heat Flow heat transfer analysis in BHM module e PRONY lt take_every gt lt below gt Enables Prony postprocessing parameters like in the postprocessing dialogue e EVS lt solutions gt lt f0 gt lt iterations gt Enables eigen value solver lt solutions gt number of searched eigensolutions lt f0 gt central frequency lt iterations gt number of simulator iterations e CIRTYPE lt type gt lt default medium gt Sets circuit type type options 2 3DP 4 2DVcoa otherwise 3D and default material metal or air e PERIODIC lt activity_x gt lt activity_y gt lt activity_z gt lt beta_x gt lt beta_y gt lt beta_z gt Defines features for periodic circuits e UNITS lt space gt lt frequency gt Sets project units space options 0 milimeters 1 micrometers 2 inches 3 mils 4 meters 5 nanometers frequency always GHz e ANGVAR lt n gt For 2DVcoa circuits sets modal angular variation range 0 99 For 3DP circuits sets phase shift per period e LOSSES lt control_string gt Controlling losses suppression and metal loss bandwidth The following substrings are recognized in control_ string M suppress magnetic losses M enabl
124. may be necessary to modify its position This can be done using Edit I O port dialogue which appears for I O ports or Edit special boundary dialogue which appears for reference planes mesh snapping planes symmetry planes NTF boxes and plane wave boxes shown in Fig E 2 4 3 1 In this window we can change several previously defined parameters of the port Let us point out only some of the specific commands available here Edit special boundary 2 x Mame iportox Mo 3 FscEdit Port type Fieference Delete m lo Port height E y Doo FP 2 i ee Activity Plus Snap mesh ta Set plane W port plane e pork circumference Ea 3 Forced cell size Pen Cancel Minu a Plus a Parameters Fig E 2 4 3 1 A dialogue for editing ports e Activity This command allows changing orientation of the port For example it is natural that a port defined at the left edge of the structure will assume the circuit to be on the right and the software will make such a default assumption However if we choose a port inside the structure an ambiguity appears In this case the default choice can be corrected here by the user e Set Plane Here we can verify the position of the port in the direction perpendicular to it We can set another position The advantage with respect to doing his with a mouse in 2D window is that we can be sure that the position of the port in the cross section of the line has not been c
125. me pro and later accessible through this shortcut Additionally the user can save the I O ports parameters in op files The user is advised to create QW _ PROJ directory and to keep the pro files in appropriate subdirectories E 4 2 Files created by QW Editor and used by QW Simulator Communication between QW Editor and QW Simulator is accomplished via text files All these files are created by QW Editor in response to File Export or File Export amp Run commands Most generally the files can be divided into three types tasker files ta3 parameter files pa3 shape files sh3 The actual number and names of files created depend on the problem to be solved In the simplest case at least one fa3 file one pa3 file and one sh3 file will be created Syntax of pa3 files can easily be deduced from examples since the parameters are strongly associated with the parameters specified by the user in QW Editor and additional explanations are included in each line following the sign Thus we shall only formulate a few general remarks regarding the keywords of tasker files and basic structure of shape files QW Editor v 6 5 105 QWED PL Chapter E 4 Files created or used by QW Editor E 4 2 1 Basic structure of shape files A typical structure of an sh3 file is presented below HEADER name version NO_OF_MEDIA for 1 1 NO OF MEDIA MEDIUM_TYPE MEDIUM_NAME list of constitutive parameters appropriate for give
126. meters dialogue window describing the parameters of dynamic template generation Now consider a dynamic template Such a template is used basically for waveguide modes However it is also applied for quasi TEM modes in inhomogeneously filled lines at higher frequencies where dispersion effects become important Dynamic template generation is a subject of detailed discussion in many examples in QW 3D User Guide Refer to sections UG 2 2 4 UG 2 2 8 UG 2 2 9 and Section UG 2 11 1 STEP 7 The discussion will not be repeated here We will only formulate some remarks concerning the dialogue as exemplified in Fig E 2 5 1 1 4 Note that e For the rectangular and circular waveguide modes explicitly listed under Exciting field QW Editor can introduce the default parameters for QW 3D analysis In QW V2D operation this capability is restricted to the following circular waveguide modes TM01 TM11 TM21 TM31 TM41 TM02 TM12 TM22 TEO1 TE11 TE21 TE31 TE41 TE51 TE02 TE12 TE22 In calculation of the default parameters the software assumes that the size of the port matches the size of the waveguide and that the waveguide is filled with air If this is not true the user should introduce the proper corrections to the set of parameters e Fora general mn mode the index m is assumed to correspond to x dimension for ports located in the XY plane or XZ plane y dimension for the ports located in the YZ plane e The symmetry boxes H V should be c
127. mits of the mesh and as such they act as the outermost mesh snapping planes However we cannot edit the edges to assign to them any particular forced cell size which we can do for explicitly available mesh snapping planes The Edges force linear mesh option alleviates this difficulty When it is checked on edges actively force the Max cell size defined in the Mesh Parameters dialogue Fig E 2 2 1 9 towards the inside of the circuit i4 Mesh Splanes info x Splanes data Splanes mesh demin 570 38461 0 el 0 4 l 171 el 04 0 4 drmin 2 5 0 35714 221 el 0 4 0 4 min 205 aU ne 0 4 ns 4 Number of cells riy 4 0 el 0 4 st FE 2 5 el 0 4 0 4 r5 el 0 4 0 4 a 10 el 0 4 gat Z 2A 0 el 0 5 Geometry 57 456 3 el 0 5 0 5 5 el 0 5 0 5 With boundaries 71 920 5 25 ne O OU FMB of PAM 14 el 0 5 nslepz U Fig E 2 2 1 10 Mesh Splanes info dialogue window o Splanes info permits to see the list of all mesh snapping planes also called Special planes created in the project The window of Fig E 2 2 1 10 appears The same window can be invoked using Info Mesh command On the left hand side of this window we can see all the special planes which may have been created in the following ways e set explicitly by the user via the Draw SPlanes boundaries command implicitly enforced by edges outermost boundaries of the circuit enforced by ports w
128. modelling accuracy Because of fast changing fields near such edges it is also advisable to refine the FDTD cells near the edge That is why the hard mesh snapping planes generated by AMIGO are accompanied by weak planes separated from the hard planes by the distance Imin master are those mesh snapping planes explicitly declared by the user outside AMIGO system They can also be viewed using Inspect command in the Mesh Control group of AMIGO dialogue From the AMIGO viewpoint all the geometrical elements of the considered structure can be classified into four groups disabled no action by AMIGO soft default AMIGO generates soft planes along edges of these elements and at their limits as well as weak planes passing through their vertices hard edges AMIGO generates hard planes along edges soft planes along the limits and weak planes passing through the vertices hard AMIGO generates hard planes along edges and hard planes passing through the vertices The properties of each element can be changed manually in the Edit Element dialogue E 2 1 3 Windows group of commands Windows allows controlling the widnows displayed if i H Quick Wave 3D 2D coa Editor File e Project Tools Help 2D Openzo z Refresh 3D Open3D H Arrange i ProjectInfo Fig E 2 1 3 1 Windows group of commands of QW Editor menu o Open allows opening a new window with three options Open 2D opens a
129. mory used for S parameter calculations at several hundreds of the frequency points usually does not exceed a few percent of the total computing time and memory needed to run the electromagnetic simulation Thus the choice of this number in the range between one hundred and five hundred seems reasonable for most applications Note that the range of frequency in which we calculate the S parameters cannot exceed the spectrum of the exciting pulse defined in the I O Ports Parameters dialogue window If this is the case the S parameters may be calculated with significantly increased numerical errors In the Advanced part of the Processing Postprocessing dialogue box we have the choice of several options e Skl at reference planes In this case we excite the circuit only from port number 1 and calculate the incident ax and reflected b waves at each port This permits to calculate S b a Note that o The simple extraction produces results contaminated by numerical reflections from imperfect absorbing boundaries QW Editor v 6 5 61 QWED PL Chapter E 2 Graphical editor o Ifthe circuit is declared as reciprocal N port it is possible to correct the value of S7 applying the expanded formula S b a S 2a2 a S 3d3 a The software enforces S S and calculates Sa brar band badr z o Ifthe circuit is declared as reciprocal lossless 2 port it is also possible to correct the value of S21 applying the formula S2 b7 a1 S22
130. n MEDIUM_TYPE Jend of media description loop STANDARD_CELL_SIZE NO_OF_SUBCIRCUITS NO_OF_PORTS NO_OF_MESH_POINTS_ALONG_ x POINTS_ALONG_y SUBPOINTS_ ALONG z for 1 1 NO_OF_SUBCIRCUITS list of types of 6 border walls list of x coordinates of mesh points along x list of y coordinates of mesh points along y list of z coordinates of mesh subpoints along z NO_OF_CELL_DESCRIPTORS list of cell descriptors NO_OF_DIFFERENT_SUBLAYERS for j 1 NO_OF_ DIFFERENT_SUBLAYERS NO_OF_SUBLAYERS_OF_TYPE_j list of cells in sublayer of type j fend of sublayer description loop Jend of subcircuit description loop QW Editor v 6 5 106 QWED PL Chapter E 5 Index E 5 Index 2D windows 18 20 3D windows 42 44 active library 63 68 AMIGO 9 AMIGO Circuit group of commands 9 AMIGO FDTD iterations group of commands 11 AMIGO Frequency group of commands 9 AMIGO Mesh Control group of commands 10 antenna 6 46 lossless 6 Automatic Meshing Intelligent Generation Option 9 buttons 17 38 house 68 lt lt lt 68 gt 68 Background Colour 43 Blend 43 Draw SPlanes boundaries 39 Draw Clear 39 Draw Element Circle polygon 39 Draw Element Rectangle 39 Draw Get Libitem 39 Draw IOPort 39 Edit 32 Edit Element 39 Edit Join Cut 39 Edit Join Glue 39 Edit Join Intersect 39 Edit Line 39 Edit Object 39 Edit Point 32 39 Edit Port 39 Edit Redo 39 Edit Select Element 39 Edit Select Object 39 Edit Undo 39 File Exit
131. n be revoked via Undo command of QW Editor Note that if this section of zednqw ini file does not exist QWV Editor will set the UndoListMaxLength parameter to zero and the Undo command will not be operational Prony are default parameters for QProny module EVS are default parameters for Eigenvalue Solver e UDOPath specifies one or more additional paths in which case the number of additional paths is given for UDO search QW Editor v 6 5 104 QWED PL Chapter E 4 Files created or used by QW Editor MeshParams specifies the number of cell descriptors that will be allocated for mesh generation In principle this number is dynamically re allocated when needed However memory management is not perfect in computer systems and for large problems it may happen that multiple holes are left in memory Then QW Editor will then not be able to allocate a single sufficiently large memory block even though the total amount of RAM is sufficient for the project If this happens a warning is issued by QW Editor and the user may cure memory management problem by increasing the number of pre allocated descriptors in this ini section o zedglob env contains a history of files recently loaded into the editor and the last set dimensions of the main window This file may exist or not when first starting the QVV Editor It is created updated upon each exit e media contains media library files m b At least one library default m
132. n but do not allow any kind of project editing In the 3D window we have one group of commands e View This group contains the commands QW Editor v 6 5 42 QWED PL Chapter E 2 Graphical editor o Displacement after pressing left mouse button over the window the cursor changes to and its movement over the window causes displacement of the image The type of displacement can be selected here as O Free Rotation a X Rotation Y Rotation Z Rotation o Switch Translate skii Background Colour opens a standard palette for selecting the background colour Fill switches between wire and solid displays Eo Undo undoes the last displacement operation Light pressed adds light to the image Blend blends the applied colours with white which produces translucency effects for solid displays Hide Ports amp Boxes pressed hides all non geometrical entities of the project I O proj Ports contours FD Monitors NTF PML Subgrid Plane Wave Mur etc Reset to Plane contains shortcut commands for setting the direction from which the image is seen i J Initial View ca from X from X E from Y A from Y from Z A from Z o Zoom a convenient way of zooming the image is with a mouse wheel Additionally there are two options amp Window Zoom pressed causes that after pressing left mouse button over the p p 8 window the cursor remains h and allows pan
133. nd Excitation waveform There are several options for excitation waveform as shown in Fig E 2 5 1 1 2 After choosing one of them its time domain shape and frequency domain spectrum are displayed schematically in the Excitation part of the window see Fig E 2 5 1 1 1 The picture is only qualitative There is however a way of obtaining precise information about a spectrum of the pulse It is available with FD Pavailable postprocessing described in Section E 2 5 2 For typical S parameters calculations we advise the waveforms of limited spectrum f lt f2 or f lt f lt f2 with the limits f and fz close to the limits of the frequency band of interest A pulse with a wider spectrum may excite unwanted resonances outside the band of interest which prolong the transient effects in the modelled circuit and thus the computing time In the case of cylindrical waveguide ports resonances can be expected around cut off frequencies of the consecutive modes Beside the frequency spectrum limits there is a parameter describing the pulse duration expressed as the number of periods of the signal of the frequency fz Setting longer pulse duration makes the pulse spectrum closer to a rectangular shape cutting the unwanted frequencies more effectively but it also prolongs the computing The duration of the length 3 to 4 is usually a wise compromise between these conflicting requirements Sometimes we need a better insight into the wave propagation at a partic
134. nd modifying the existing ones Filename of the executable assigned to each tool is provided as well as default argument where appropriate QVV Editor stores this information in registers and always first looks into registers when trying to pick up a tool If there is no relevant information in the registers QW Editor further looks for Zednqw ini file from envir directory see Chapters E 4 for more detailed discussion QW Editor v 6 5 14 QWED PL Chapter E 2 Graphical editor 1H Set Tools Path Insert Yar Set Path lt INSTALLDIR gt qubin SAT Viewer Set Default Filename Set Filename SAT Filter wf Enable Arguments OSF Converter z kerl EXE UCO Editor Check if exists Set Path rguments Insert Yar Insert File Set Filename PROWECTFULLNAME gt ta Visible New Ren Del C Not isible Visible in Tools C Wisible in My Tools Cancel Default All Help Fig E 2 1 5 2 Set Tools dialogue Set Tools dialogue allows to the user set the path filename and argument for the programs or back to default settings via Set Default or Default All button There are seven predefined tools O Calculator the default path and filename is calc exe a standard calculator available in Windows system There are no default arguments Notepad the default path and filename is notepad exe a standard text editor available in Windows system There default argument is lt PROJECTFULLNAME gt txt Simul
135. nents The lumped port will serve as a source or a probe depending whether Source or Load will be checked in the I O ports dialogue In both cases in the I O Ports Parameters dialogue see also Section UG 2 11 2 STEP 7 the user must define afield component to which the port is connected e internal resistance of the port a value from the 0 INF range or self adjusted to match the neighbouring FDTD mesh For ports checked as Source the user will additionally define the source waveform amplitude and delay Setting no excitation waveform effectively transforms the source into a load For ports checked as Load zero exciting amplitude is assumed and the lumped port acts as a lumped resistor QW Editor v 6 5 45 QWED PL Chapter E 2 Graphical editor The Lumped source probe port can be used in the following cases e as a virtual source in eigenvalue problems resonant modes their frequencies and Q factors in a resonator e asa dipole in the analysis of dipole excited antenna problems e as a lumped source of finite output impedance in the calculations of embedding impedance for lumped elements aS a probe especially in millimetre wave problems taking part in S parameter extraction together with Transmission line ports In the latter two cases the point source or probe should be placed in a one cell gap between two metal elements If the gap for example between two metal plates is larger than one cell the so
136. netic loss are given by Debye Drude or Lorentz dispersion model with user specified parameters For permittivity the same relations as above are used for permeability they become Drude L mu_inf 27 ay j 2nv_c Debye L mu_inf mu_s mu_inf 1 J tau Lorentz L mu_inf mu_s mu_inf 27 fpy 27 fpy j 2nv_c where mu_inf relative permeability at infinite frequency unitless mu_s Static relative permeability unitless Limits on media parameters analogous to those for dielectric dispersive as above apply Fig E 2 5 3 1 shows the form of the window for Dielectric isotropic medium in which case only three electromagnetic parameters and three thermal parameters are set Variants of the window for Metalic Dielectric dispersive with Lorentz dispersion model Metamaterial with Drude electric dispersion and Debye magnetic dispersion and Ferrite medium The display for PEC is not shown since no parameters need to be specified was Library medium Project media Name Type metloss x Metalic JE Del Dispersion model METAL eee Ment Electromagnetic parameters Mu Sigma f e 007 Fig E 2 5 3 2 Parameters Media dialogue window for Metalic medium QW Editor v 6 5 65 QWED PL Chapter E 2 Graphical editor Jj Edit media library lt INSTALLDIR gt media default mlb eae ajx Library medium Project media Type a ai metal i ielectnic ani i
137. ng for udo files if they are not found at the originally indicated location Recent files shows a list of files that have recently been loaded Erase provides commands for clearing the history of Recent Files Windows History and Undo List Exit ends the QW Editor session and saves the program environment On the next entry to the QW Editor we will automatically get the display of the last project with the same windows settings as before the Exit command E 2 1 2 Parameters group of commands Parameters allows setting basic information about the project and the desired way of its analysis O Amigo opens Amigo dialogue with the basic choice of FDTD Mesh control in a Manual way or by a fully automatic AMIGO system Parameters for the AMIGO system are set in the same Amigo dialogue AMIGO is a new feature of version 6 0 described in Section E 2 1 2 1 Circuit type allows setting dimensionality and basic media environment of the project Iis also accessible through the Setup Circuit type path and it is described in Section E 2 2 1 I O Ports allows configuring ports of the structure see Section E 2 5 1 QW Editor v 6 5 8 QWED PL Chapter E 2 Graphical editor 1 Quick Wave 3D 2D coa Editor File Parameters Windows Project Tools Help gt 2 Amigo Ctrl 4 Circuit Ctrl T he Postprocessing F Media Hk units Fig E 2 1 2 1 Parameters group of commands of QW Editor menu o Postprocessing allows request
138. ning a region of the window Up Down Zoom pressed causes that after pressing left mouse button over the window the cursor changes to and its movement up or down zooms and unzooms the image respectively o Save Copy to Clipboard captures window contents to clipboard Dump Pixmap saves window contents to a bmp file of user defined name o o 5 Elements opens View Elements dialogue which allows showing or hiding individual elements Its form for the wgtocx1 pro example is shown in Fig E 2 3 2 Elements can be selected unselected with mouse clicks or via Sel All Unsel All buttons Elements can be shown or hidden by pressing Show Sel or Show All or Hide Sel or Hide All confirmed by Apply or OK Double click over H or V letter in Visible column followed by Apply or OK is QW Editor v 6 5 43 QWED PL Chapter E 2 Graphical editor an alternative way to show or hide a particular element All other columns are for information only Show and hide operations performed from this dialogue prevail over possible previous Hide Boxes command Cancel exits the dialogue without performing the last requested unconfirmed operations View Elements Element E Bea amna Input Template 1 E foomu abotna 5 Ejoor Feee le Ww 6 Fel All Show Sel Show All Apply Help Unicel All Hide Sel Hide ll Cancel E Fig E 2 3 2 Example View Elements dialogue for the wgtocx1 pro example with antenna element selec
139. nitial temp C When solving Maxwell equations in lossy media we multiply certain terms by a factor fi fi 1 0 5 o At e E 2 5 3 1 and we divide certain terms by a factor f fa 1 0 5 0 At E 2 5 3 2 The terms f and fp are responsible for attenuation of the fields Thus for losses to be effectively considered by the FDTD implementation with floating point arithmetics the following condition must be obeyed f 0 5 o At gt 1 10 E 2 5 3 3 Materials where f lt 1 10 are treated as lossless ones In the above relation o 1s conductivity in S m and is real permittivity in F m and At is FDTD time step which can be checked in Simulation Info window The users interested in modelling very small losses have the following options QW Editor v 6 5 67 QWED PL Chapter E 2 Graphical editor Option 1 recommended Scale the problem by increasing o so that relation 3 is obeyed Note that small losses practically do not change the EM field patterns and dissipated power patterns scale linearly with medium conductivity Thus if with o 1000 one obtains dissipated power density P2 then with o dissipated power density at the same point may be safely assumed as P 0 01 Ph Option 2 Try to apply coarser discretisation in space causing larger value of FDTD time step At Parameters of the media can be modified To the right from the media parameters table we have three additional commands concern
140. nt of zero height right after HV Grid button is pressed Definition of ASBC with wiregrid udo Rectangular wire grids can be defined in QW 3D with wiregrid udo Invoking the Draw Get Libltem command and selecting wiregrid udo shows the following dialogue with default parameters QW Editor v 6 5 40 QWED PL Chapter E 2 Graphical editor imee 0 Cancel Wire grid in 7 plane if h 0 in 2 or Y plane if h0 Pressing Draw creates a rectangular wire grid perpendicular to the X axis at x X1 X2 2 based at level Z 0 with height h 1 between Y1 1 and Y2 3 all in current project units The grid will be filled with horizontal Y oriented see Tab E 2 2 7 1 wires If the FDTD mesh lines are at z 0 1 2 the y oriented wires will appear at z 0 1 The user can modify the parameters creating different wire grids Note that O O The grids must be planar not volumetric Consequently we must make one of the three settings h 0 or X1 X2 or Y1 Y2 Otherwise a warning will appear Orientation boxes allow to choose horizontal and or vertical wires Setting Orient_h x 1 will create horizontal wires Orient_v y 1 will create vertical wires If both orientations are set to 1 a 2D mesh of wires will be created this will no longer imitate ASBC but rather to a thin metal plate If none of the orientations is checked no wires will be created If d gt 0 all wires in the grid will have diameter d In such a case
141. nterested in a particular mode of propagation in the line To extract any parameters at the Transmission line port we will need to calculate a mode template as explained in further Sections Before clicking Draw the user must specify whether the port is Perpendicular or Parallel to XY plane which entails that it will be drawn as a line or rectangle respectively e The port can be defined as Source or Load The declaration of the port as a source means that it will serve as the input port in the case of Sk1 element analysis which uses excitation from one port only To avoid confusion in the S matrix interpretation it is recommended that this port be marked as port number one In the case of Smn analysis each port included in S parameter extraction will serve as a source in one of the consecutive simulations Ifthe Transmission line port is included in S parameter extraction via S as port No option a reference plane will be automatically generated by QWV Editor at a default distance from the port If the S option is not checked the port can serve as source or load but it will be ignored from the point of view of S matrix analysis QW Editor v 6 5 46 QWED PL Chapter E 2 Graphical editor e Absorbing wall Such a port is used for absorbing termination of a chosen rectangular part of the FDTD mesh It is not used for extracting any parameters for further postprocessing The absorbing boundary condition is Mur with superabsorbing
142. ny number greater than zero leaves also one copy of the marked element s in the original position For example with the settings presented in Graphical editor Select object E x Object name Dfe fe Zale roma B jnen roma W Marked Active Passive Apply UDGFiE Delete Help Close i Fig E 2 2 2 8 Select object dialogue window Fig E 2 2 2 9 we can produce the following effects o Exec in the Shift zone will move the marked element s by one unit in the z direction o Exec in the Rotate zone will make a copy of the marked element s rotated with respect to original by 30 degrees Note that the axis of rotation is the point of the last left mouse click over the active 2D window o Clicking over ShiftG amp Rotate will produce 5 copies of the marked element s each one shifted by one unit in Z direction and rotated by 30 degrees Note that one possible application of the Shift Rotate option may be drawing of spiral conductors o Exec in the Mirror zone will create a mirror image of the marked element s with respect to the xy plane o Clear in any zone clears the settings introduced in that zone Attention It is the user s responsibility to avoid producing intersecting elements during this operation If such elements are produced they should be treated using Join option prior to the FDTD simulation Otherwise they may cause incorrect calculation or even a run tim
143. o the metal surfaces The FD probing calculations will be performed on the current flowing between the source and the circuit and on the port voltage selected E field integrated along the FDTD cell containing the Lumped source probe In the QW Simulator we will see the Fourier transform of the current and voltage the embedding impedance and admittance versus frequency and the port reflection coefficient calculated with respect to the internal resistance of the Lumped source probe if it is different from 0 and with respect to 50 ohm otherwise Note that the calculated embedding impedance includes in parallel the capacitance of the FDTD cell into which the lumped source probe has been inserted This happens because the current considered by FD probing comprises two components current flowing into the metal embedding the circuit and current flowing into the cell capacitance If the latter component should not be considered in a particular application the S differential postprocessing should be selected instead of FD probing An example of application can be found in e g Section UG 2 3 4 o Extraction of currents and voltages by integrating H fields along a virtual loop surrounding a conductor and E fields along a virtual line connecting two conductors This information may be helpful in the analysis of quasi TEM circuits for verifying the frequency range of their TEM behaviour Also lumped element models of parts of 3D structures can be extract
144. of iterations calculated by Amigo he will resume the simulation to see if the obtained characteristics really converged adequately to the final solution This will help in setting in the next runs the frequency resolution giving the best results in reasonable computing time In most cases an experienced user will be able to set easily a correct number of the frequency resolution in Amigo or directly the needed number of iterations based on previous experience with the particular types of circuits To terminate the subject of needed number of iterations let us note that in the case of structures of very high Q an optional signal postprocessing module QProny can be used to decrease the needed number of iterations QW Editor v 6 5 6 QWED PL Chapter E 2 Graphical editor E 2 Graphical Editor E 2 1 Main menu and submenus of QW Editor After entering into the QW Editor we can see the menu together with submenus This menu contains six groups of commands E 2 1 1 File group of commands ue Quick Wave 3D 2D coa Editor File Parameters Windows Project Tools Help New Ce PEG By Hr 7 2D ar 2 Load ctrl o Save Ctrl 5 Save AS axioo Exp Export a 0 TT DE Export amp Run Fa Export amp Test Ka Export Run amp Start Export Rum amp Start Prony Export Options UDOPath Recent Files b Erase Exit x X e E oan Windows History 465 Undo List Fig E 2 1 1 1 File
145. olume Instead it will apply special surface impedance boundary conditions along the metal surface to represent the frequency dependent skin effect Therefore this option should be used in the case of metals of finite but very high conductivity Details about the model and its implementation are discussed in references 32 105 in Chapter UG 3 e Dielectric isotropic Electric permittivity Eps dimensionless magnetic permeability Mu u dimensionless electric conductivity Sigma o S m and magnetic loss SigmaM Om 120 2 ouou 120 m Q m can be declared e Dielectric anisotropic It uses the same parameters as dielectric isotropic but different values can be set in different directions e Ferrite denotes a ferrite medium magnetised with a static z oriented magnetic field It has all the parameters of dielectric isotropic and additionally the parameters of the ferrite model damping constant alfa unitless saturation magnetisation Ms T and static biasing z directed magnetic field Hi A m Details about the model and its implementation are discussed in references 90 104 in Chapter UG 3 e Dielectric dispersive has magnetic permeability Mu u dimensionless electric conductivity o S m and magnetic loss SigmaM Q m defined analogously as for dielectric isotropic Its complex relative permittivity including series losses is given by Debye Drude or Lorentz dispersion model with user specified
146. olygon Wire T 10Port Rectangle orks a Circle polyqon a SPlanes boundaries I NTF box E Element Plane wave box Object Get fm Libltem Ifo aon Object i Je Next Clear 0 Close Fig E 2 2 3 1 Draw group of commands of QW Edit menu e Combined Element This element is being introduced at first in a similar way as a normal element However after it is introduced its bottom and cover can be selected separately and cover can be edited without influencing bottom To check this please draw a rectangular combined element Then please invoke Edit Select Element command and click over the line in which the cover part is listed Now click over the introduced rectangle move it and click again You can see in the 3D windows the modified shape of the combined element e Bi phased Element if this is chosen from the Draw menu you will obtain a biphased element e Bi phased Combined if this is chosen from the Draw menu you will obtain a combined biphased element e Wire This command permits to define thin wires of radius less than a cell size parallel to any of the coordinate axes Starting with version 2 0 the Wire command can also be used to define grids of wires in XZ or YZ plane We shall consider this possibility in Section E 2 2 7 and herein concentrate on a single wire Modification of the wire diameter can be accomplished through the Edit command executed on the wire also described in Section E 2 2 7 Remembe
147. on delimiter arguments separator substitution amp amp logical and Il logical or string concatenation Math functions sin cos tan asin acos atan atan2 trigonometric functions and their inverses Attention Arguments of trigonometric functions and results of their inverses are degrees log logd exp sqrt abs sgn int frac rand srand mathematical function QW Editor v 6 5 103 QWED PL Chapter E 4 Files created or used by QW Editor E 4 Files created or used by QW Editor During its operation QVV 3D creates and uses a variety of files which can be grouped into five categories 1 files used by QW Editor created by QW Editor or externally 2 files created by QW Editor and used by QW Simulator 3 files created and used by QW Simulator 4 files created by QW Simulator for external use 5 externally prepared files used by QW Simulator In this Section brief overview of each of the above five categories will be presented The objective is to give the user some notion about the contents of the files that will appear in his directories about the possibilities to influence the graphical environment and about the kind of output data available for external use Let us also stress that to the authors of the program the files of the second category 1 e the communication files between QW Editor and QW Simulator provide powerful means for software debugging Since all these files are in text format the user will b
148. ones in the conflicting areas o Normally the Select Element command changes the local 2D coordinate system of active 2D window to the base of the element in the XY plane If we wanted to move the excitation point in a port perpendicular to the XY plane we would prefer to have the local 2D system situated in the plane of the port This can be achieved by selecting the port and then clicking over Select P lane e Select Object This command permits to select one of the objects groups of elements defined in the project A list appears which contains all the drawn internal and external objects Each may be followed by status letters E O C denoting that the object is empty contains no elements or objects open elements or objects can still be added current elements or objects are currently added to this particular open object After selecting the object the program automatically executes the Edit Object command Note that the external objects are parameterised and their dimensions can be modified The internal objects are simply groups of elements which can be moved together QW Editor v 6 5 32 QWED PL Chapter E 2 e Reproduce This command operates on the group of marked elements These elements are drawn with thick contours Elements can be marked or unmarked in the Select element dialogue window Marked elements can be shifted rotated or reflected The number of copies indicates how many times the operation should be performed A
149. or v 6 5 82 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language o In the above example full path to the points txt file has been given Other possibilities of specifying the file location are summarised in Section E 3 10 o READF function can be also used to overwrite the current values of variables This opens a way for external modification of the shape of an object drawn using an UDO Such a possibility is actually often used when QW 3D is applied together with an external optimiser It is described in Section S 3 7 of this manual E 3 5 Loops in UDO language When we want to specify an ordered distribution of lines or elements we need to create a loop structure In the UDO language the if and while instructions can be used for this purpose They have the following syntax Syntax of loops e if lt ogical expression gt do endif Instructions between do and endif are interpreted if logical expression is true e while lt Jogical expression gt do endwhile Instructions between do and endwhile are executed in loop as long as logical expression is true Additional remarks There is a very important difference between the equality sign used in logical expressions and the substitution sign used in equations Using the later one in the logical expression will actually execute the substitution Thus it will not only cause incorrect loop operation but may change the operation of the
150. ormal FD TD method must be a cuboid composed of one medium or a cuboid divided by a plane into two parts filled by different media Meshing is done automatically by QW Editor just before the Export QW Editor v 6 5 70 QWED PL Chapter E 2 Graphical editor operation QW Simulator reads the meshing information coded in sh file and assigns to each of the cells proper electrical parameters depending on the cell s shape and media filling As it was mentioned the meshing is performed automatically by QW Editor However there are certain important rules to be obeyed while introducing the geometrical data We need to provide to the mesher consistent information leading to the expected results of the meshing process Here we would like to draw the user s attention to several situations which may cause meshing problems and thus should be avoided in projects They first concern intersecting elements multiple filled cells and meshing hazards along the Z axis Intersecting elements Important definition Two elements are defined to be non intersecting if they obey the following condition In each of the cross sections parallel to the XY plane the pair of the elements is either disjoint or one of the elements is entirely included in the other If an element A is included in element B but their borders partially coincide the elements can be treated as non intersecting only if the element A is defined as filled inside by a particular medi
151. otation dialogue window Level Here we can move the level of the local coordinate system we could do it also using Plane command but in a little more laborious way Moreover we can set here the default height of the next element to be introduced in the QW Editor Note that the level as well as the current default height of the element to be created are displayed in the lower part of each 2D window together with the cursor position expressed in the local coordinates Note that this option is irrelevant for QW V2D where the default level of 0 and height of 1 are fixed Below we present the options available in the Level window Level 2 fo Default H f Bottortop kind f Electric Medium Name open ki i Neutral Suspended Help Cancel ok Fig E 2 2 1 5 Define Level dialogue window Zi o default medium filling of the currently drawn element o bottom top kind of the currently drawn element This field indicates if the bottom and top of the element will be Electric will enforce the E plane of FD TD meshing as discussed in Section UG 2 1 e Magnetic will enforce the H plane of FD TD meshing as discussed in Section UG 2 1 e Suspended will enforce a plane suspended between those considered above Axes Here we decide how the local coordinate system should be displayed in the 2D window Note that the 2D window is composed in a way to include the entire project and the axes Thus if the axes are
152. ote also that the considered source has been marked as NR 1 This means that it has been declared as one of the ports considered in S matrix analysis see Section E 2 4 1 for reference When the source is not supposed to take part in S matrix analysis it would be marked as port NR 0 The lumped probes act as the lumped sources with excitation equal zero Thus it can serve as the elements probing field in free space or the resistive probes between two metal parts They can be numbered as ports of S matrix calculation or just serve as potential points for FD probing see the chapter on Postrocessing QW Editor v 6 5 56 QWED PL Chapter E 2 Graphical editor ES 1 0 Ports Parameters Mame E scitation D Waveform irp siga puse of spectumik2 l Point NA Ez v a Frequency i LO SOURCE F ohr H j GHz H fe 3 GHz No of 1 0 ports 8 re E 50 Self adjust Duration 3 e HO WARNINGS Amplitude Delay na i TEE e Put Fig E 2 5 1 3 1 The relevant parts of the I O Ports Parameters dialogue window in the case of a lumped source Mult EM The I O Ports Parameters dialogue for the case of a lumped impedance is presented in Fig E 2 5 1 3 2 Its application is described in the Section UG 2 17 Here let us only point out that they can be connected to the considered structure in a similar way as the lumped probes However they cannot be used as ports neither for S parameter extr
153. ource probe type which have been marked as taking part in FD probing cf Fig E 2 4 1 1 the software will calculate Fourier transforms of terminal voltage and current and therefore extract embedding impedance and admittance If contours are defined in the project field integrals along these contours will also be Fourier transformed The user specifies the frequency range of calculations There are four main applications of this type of postprocessing Analysis of eigenvalue problems resonant frequencies and field distribution of consecutive modes in arbitrarily shaped and filled resonators In this case a Lumped source probe must be placed inside the resonator It will serve as auxiliary excitation injecting energy into the structure through finite output impedance We can watch the results of FD probing calculations performed on the current flowing between the source and the resonator With pulse excitation minima of this current indicate resonant frequencies The background theory of this approach has been explained in publications 14 26 An example of application can be found in e g Section UG 2 5 1 Se a ee 2 x P FD prabing aaa bo al step jon laHz M FD Pavailable 5 sito TS spf o GH M S diferential 18 tofo step 05 GHz M Bides fe ojs s pjin o GH Eigen values E solution s near 10 GHz with foo iter W Nearto Far 025 GHz FFDMonitrs Oo GHe Help Cancel ox S comectione assuming Processing
154. parameters Drude Elo eps_inf 27 fp jo2nvc Debye amp eps_inf eps_s eps_inf 1 j tau Lorentz amp eps_inf eps_s eps_inf 2n f py 27 fpy j 2nv_c where eps_inf relative permittivity at infinite frequency unitless eps_s static relative permittivity unitless tau relaxation time ns v_c inverse of the relaxation time collision frequency GHz f_p pole frequency plasma frequency GHz QW Editor v 6 5 64 QWED PL Chapter E 2 Graphical editor For Debye and Lorentz eps_s lt eps_inf is not allowed and eps_s eps_inf causes that the medium is considered as dielectric isotropic with frequency independent permittivity eps_inf and conductivity Sigma For Drude and Lorentz f_p 0 causes that the medium is considered as dielectric isotropic with frequency independent permittivity eps_inf and conductivity Sigma For Debye tau 0 causes that the medium is considered as dielectric isotropic with frequency independent permittivity eps_s and conductivity Sigma There are also limits on the admissible level of losses with respect to the FDTD time step 4t For Debye the requirement is tau gt 0 5 At for Drude and Lorentz 27 v_c y gt 0 5 At e Metamaterial has electric conductivity Sigma o S m and magnetic loss SigmaM Q m defined analogously as for dielectric isotropic Its complex permittivity including series loss and complex permeability including series mag
155. phase elements may be drawn by declaring one of three other possible types 10 simple biphased element 15 bottom of combined biphased element 16 cover of combined biphased element Previously used monophased elements were enforcing a sublayer of the FD TD grid at its bottom and top Contrary to that biphased elements do not enforce any mesh snapping in the DRAFT phase of QW Editor operation The DRAFT phase is used to set the proper distribution of mesh sublayers Then in the FINAL phase the biphased elements are drawn in a way to fit the mesh Syntax of commands used in biphased objects e SLICINGPHASE Function returning 0 when QW Editor is in the DRAFT phase and J when QW Editor is in the FINAL phase e MESHINDEX lt level gt A function returning The ordinal number of the sublayer of FD TD mesh situated most closely at or below Zevel if there is an FD TD mesh at or below level 1 if there is an FD TD mesh but situated above level 2 if there is no FD TD mesh e MESH lt n gt A function returning the level at which the n th sublayer of the FD TD mesh is situated The sublayers are counted up with the lowest sublayer numbered 0 e EXPANDMESH lt lowerlevel gt lt upperlevel gt Expands mesh limits in z direction between lowerlevel and upperlevel to allow direct drawing of biphased objects in the FINAL phase of the Editor without previous drawing in the DRAFT phase It does not work when direct mesh limits
156. phical editor Export options fx Suppress singularity corrections Suppress density SAA Allow BHM Details Cancel Fig E 2 1 1 2 Export option dialogue window Suppress singularity corrections means that field singularity corrections will not be applied at metal edges corners and wires Suppress density SAR means that density and SAR matrices will not be allocated in QW Simulator It is a fast way of reducing memory requirements in preliminary simulations of the problems prepared for further thermal simulations Allow BHM is an option available to QW 3D users who have additionally acquired QW BHM modules it instructs QW Simulator to reserve more memory needed for QW BHM operation Allow heat flow is conditional upon Allow BHM It means that heat transfer analysis will be performed at each BHM step if a proper Heat Flow module is set in Set Tools of QW Simulator and if all thermal media parameters are defined in media pmo files Allow rotation is conditional upon Allow BHM It means that load will be rotated at each BHM step with rotation parameters set via Details button It instructs the QW Editor to prepare all files that are necessary to perform simulation of heating of a rotating load the parameters of the rotation can be set in a dialogue window displayed on screen after Details button is pressed UDO Path opens Set UDO Path dialogue It allows setting the directories where QWV Editor will be loooki
157. plied by many authors It is currently one of the most popular methods among microwave circuit researchers The version of the FDTD method applied here is based on the research conducted by W K Gwarek and his co workers The main difference with respect to the classical FDTD method is much more flexibility in the shape of individual cells This reduces the main disadvantage of the classical FDTD which is the necessity of stair case approximation of curved boundaries QVV 3D software also contains many other features based on the original research see Chapter UG 3 or V2D 3 for references In most of the FDTD applications we use a pulse excitation at one or more ports of the modelled device After the wave simulation is accomplished the comparison of the Fourier transforms of the input and output signals gives the S matrix parameters of the circuit Furthermore the Fourier transforms of tangential fields on a surface enclosing the antenna or a scatterer can be used to extract the radiated or scattered far fields respectively Theoretically the Fourier transform calculations require infinite period of time However since the exciting pulse has limited duration and the power entering the circuit is being dissipated at the input and output which are matched or at the absorbing boundaries the signal at the ports becomes negligible after a limited period of time and the Fourier transform calculation can be limited to this period without causing signifi
158. r TEM port limited by two electric and two magnetic walls the field distribution is constant in space Thus we do not need to calculate it but can just assume the constant field distribution with a vertical V or horizontal H polarisation We need to be careful when applying planeTEM excitation It is up to the user to verify that the port obeys the above mentioned assumptions and that the polarisation is correctly chosen Its application may save quite a lot of QW Editor v 6 5 53 QWED PL Chapter E 2 Graphical editor computing time when planeTEM assumptions are met and the port is large in terms of the number of FDTD cells H 1 0 Ports Parameters T A 2 x Excitation Mame C Seta dake Wawelem silani R TEID pulze of spectrum Hetite r Transmission line HA 1 I0 SOURCE Permitivity Symmetry effective No of 170 ports 2 M Auto 0 55617 C H OY HO WARNINGS Set All Next Frew Get TEM Cancel Help Fut Template Advanced Parameters Set All Template mode search details Excitation with Jez field component Eigenvalue search js000 Iterations after delta pulse proceeded by sinusoidal excitation for ioon iterations and source disconnection for fio iterations Generation i Automati Permittivity eff Mente as5617 gt Manual Matching frequency within 225 GHz fio GHz Template mode searching range Freg from to step Fig E 2 5 1 1 4 I O Ports Para
159. r of the element in XY plane Thus we have the commands NEWLINE x1 x2 y1 y2 ADDLINE x2 y2 CLOSELINE It is very important to close the line Lines not closed may cause that during the meshing process the medium will pour out of the contour making the entire meshing incorrect Note that if the drawn line is parallel to X or Y axis ADDLINE x2 y2 can be replaced by simplified commands with incremental argument ADDY dy or ADD X dx This is exemplified in the definition of the last element cubic3 which is much simpler that the definition of the first element cubic The consecutive points of the contour of the element must be left counter clockwise oriented Violation of this rule may result in confusion about what is placed inside the contour and what is placed outside it Thus please be careful about that The third parameter indicates the type of element In the case of a simple element this parameter should be set to 0 In the case of a combined element we use a pair of frames ELEMENT ENDELEM The first one describes the bottom of the combined element and its type is 5 the second describes the top of the combined element and its type is 6 Thus in the threeel udo we have three elements but four frames ELEMENT ENDELEM The first one declares the element cubicI name of the element is the 5 th parameter the following two a combined element prism with the bottom prismb and the top prismt and the fourth
160. r that wire diameter should be set in current project units in QW 3D versions earlier than 1 8 the wire QW Editor v 6 5 35 QWED PL Chapter E 2 Graphical editor diameter always had to be set in millimetres The way of drawing a wire is different for Z oriented wires and for wires located in the XY plane To draw an X or Y oriented wire first invoke the Setup Level command and specify the level of this wire setting its height to zero Then invoke Draw Wire which will allow you to draw the wire as a line segment Drawing a Z oriented wire in slightly more complicated First invoke the Setup Level command and specify the level of wire base and the wire height Then invoke Draw Wire which will allow you as for the X or Y oriented wires draw a segment of the line in the XY plane Do this in such a way that one end of this line is at the desired position of the wire Then call Select Point and move the other end to the same position e J OPorts This command will be described in detail in Section E 2 4 1 e SPlanes boundaries This command will be described in detail in Section E 2 4 2 e NTF box This command is used to create a virtual box needed for antenna simulations It introduces absorbing boundaries around and sets the boundaries on which the Near To Far transformation will be executed for the purpose of calculating the radiation patterns To introduce a box we draw a rectangle The box will be created at the current level with cur
161. raged to refer to QProny manual available on the installation CD e Near to Far transformation We calculate the radiation patterns of a radiating structure or scattering patterns of a scattering structure irradiated by a plane wave at frequencies specified in this dialogue This type of postprocessing is available only if NTF box has been previously defined in QW Editor Remember that for correct radiation pattern extraction the NTF box must fully surround the structure and be itself surrounded by a homogeneous medium terminated with absorbing boundaries except for symmetry and ground planes The NTF frequencies can be introduced in any order and theoretically any number of them can be considered However note that collecting the NTF data for each new frequency Fourier transforms of four field components in each cell on the NTF box is quite consuming in terms of computer memory and computing time A majority of Near to Far applications are in air which is a natural environment for a majority of antennas However radiation patterns and antenna efficiency in dielectrics and even in lossy dielectrics may be of interest in e g biomedical studies Near to Far postprocessing in QW 3D has been especially adapted to such cases in versions 5 0 and 6 0 respectively The medium outside NTF box may be any isotropic dielectric However Near to Far will not automatically recognise the medium parameters They must be explicitly repeated in the NTF backgroun
162. rect but the simulation time may drastically increase if the mesh snapping properties of the port circumference imposed on the mesh snapping by the geometry produce a very small cell This discussion underlines that if the user decides to draw a port in a manual way this operation needs to be done with special care QW Editor v 6 5 47 QWED PL Chapter E 2 Graphical editor Fig E 2 4 1 2 A fragment of a 2D window showing input port marked by a red line with three red arrows and its reference plane for S parameters calculation marked by a blue line with one blue arrow The ports in XZ and YZ planes are introduced in a way similar to elements with the only difference that their base is a straight line while the elements have polygonal bases The ports in XY planes are introduced in a similar way as a rectangular base of an element Note that checking the port for S automatically introduces a reference plane situated at some distance from the port Fig E 2 4 1 2 The reference plane is the plane at which the data for S parameter calculation is collected The user should move it to the proper position taking into account the following criteria e It must be situated in a place where the cross section of the I O transmission line is the same as in the I O port plane e It must not be closer than two cells from the I O port but for better accuracy it should rather be moved at least 4 5 cells towards the circuit e The S parameters are
163. rent height set in Set Level dialogue and with the size in XY plane corresponding to the drawn rectangle The NTF boundary will be separated from the absorbing walls by 10 of the size of the box After drawing the NTF box we can invoke Select Element command to see on the list seven new elements six absorbing sides and the NTF box Each of these elements can be edited or deleted like other elements In particular we can change the size and position of the NTF boundary through the Edit special boundary dialogue described in Section E 2 4 3 Above we described a possibility of introducing the NTF box in a manual way However with the new system of libraries introduced in version 2 1 we expect that most of the users will prefer to use the special NTF box generating UD Os available in the library elib boxes e Plane wave box creates an auxiliary surface used for exciting an incident plane wave To introduce a plane wave box we draw a rectangle The box will be created at the current evel with current height set in Set Level dialogue and with the size in XY plane corresponding to the drawn rectangle After drawing the plane wave box we can invoke Select Element to see it on the list and to select it for editing its size and position through the Edit special boundary dialogue described in Section E 2 4 3 Parameters of the plane wave to be excited will be defined through the I O Ports Parameters dialogue described in Section E 2 5 1 Sim
164. res In the latter case the project to be optimised must comply with following rules 1 The project must contain at least one UDO object 2 The object must be of the same name as the project This and only this object will be reconstructed whenever the QW Editor is called with m parameter cf Section E 2 8 3 There are two basic possibilities of actually modifying the object between successive iterations of the optimisation process e The first is to directly modify the corresponding udo file Remember that udo files are text files of strictly defined structure Therefore this way of operation is possible but highly prone to any operator s mistakes related to finding replacing appropriate fragments of the udo file e The other possibility safer and thus recommended is to prepare the relevant udo file in such a way that the values of variables taking part in the optimisation process are read via READF function from txt files The external optimiser will only need to modify or replace these txt files which may be short and simple Note that for this operation to be effective all variables to be modified in the optimisation process must be declared as parameters in the object header via PAR function The object can also contain additional parameters not used in the optimisation process QW Editor v 6 5 98 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language E 3 12 UDO command
165. rguments of MEDIUMPAR will be ignored This command allows using material permittivity permeability etc as UDO parameters Thus it allows for example changing medium parameters in a quasi continuous way as variables modified in a loop The names of parameters see Fig E 2 5 3 1 THERMALPAR lt mediumname gt lt ini_temp gt lt spec_heat gt lt therm_cond_X gt lt therm_cond_Y gt lt therm_cond_Z gt analogous to MEDIUMPAR but sets thermal parameters initial temperature specific heat and thermal conductivity in the three coordinate directions MEDIUMCOL lt mediumname gt lt pen_R gt lt pen_G gt lt pen_B gt lt pen_style gt lt pen_width gt lt brush_pen_R gt lt brush_pen_G gt lt brush_pen_B gt lt brush_bkg_R gt lt brush_bkg_G gt lt brush_bkg_B gt lt brush_style gt Defines the pen and brush attributes associated with the medium mediumname lt pen_R gt lt pen_G gt lt pen_B gt RGB parameters of the medium pen line colour lt pen_width gt the medium pen line width lt pen_tyle gt the medium pen line style 0 continuous 1 dashed 2 dotted lt brush_pen_R gt lt brush_pen_G gt lt brush_pen_B gt RGB parameters of the medium brush pen colour lt brush_bkg_R gt lt brush_ bkg _G gt lt brush_ bkg _B gt RGB parameters of the medium background brush colour lt brush_tyle gt the medium brush style hatching style DISPERSION lt mediumname gt lt mo
166. rientation is correct and if necessary change it using the Edit Port command e In the upper right part of the I O ports dialogue we should define the name of the port This name may be useful for example to select a particular port on the list of elements We can also change the number assigned to the port for the purpose of the S parameter calculations e The ports which take part in S matrix calculations must bear consecutive numbers For example assigning to three available ports the numbers 1 2 and 4 will result in computation error e We should avoid the situation in which the FDTD cells adjacent to two sides of a reference plane differ significantly in size measured along the direction of propagation This introduces some error into S matrix calculation Fig E 2 4 1 2 shows a zoomed display of a transmission line input port It emphasises one more crucial issue in the transmission line port definition Namely line marking the port should be drawn parallel to one of the coordinate axis precisely within the metal body of the waveguide In fact QW Editor will not allow you to draw the port obliquely However if you draw the port parallel to the Y axis but either too short or not starting precisely at the metal wall only a part of the guide cross section will be used for energy injection leading to wrong simulation results If you draw it too long protruding into the metal wall of the guide or even further the simulation results may be cor
167. rl Z i Info Mesh Edit Redo Ctrl Y Edit Reproduce Edit Point CE Edit Join Cut F Edit Port Edit Join Glue Edit Line om Edit Join Intersect Edit Element E 2 2 7 Additional remarks on wire grids asymptotic boundary conditions Asymptotic boundary conditions ASBC have been introduced following a suggestion of some of our users ASBC are defined by setting to zero one of the electric field components over the region covered by ASBC and thus can be realised as wire grids Regarding the orientation and geometry of ASBC the following restrictions apply in QW 3D o ASBC can only be defined in planes perpendicular to one of the coordinate axes o in vertical planes parallel to XZ YZ ASBC must have a rectangular shape o in horizontal planes parallel to XY arbitrarily shaped ASBC can be drawn but a stair case approximation will be made Note that formally speaking ASBC can also be introduced by drawing appropriate grids of individual wires There is however one major practical difficulty in such an approach the user has to draw each wire separately exactly following the existing FDTD mesh After re meshing of the project the wire grid has to be re drawn Those problems are avoided by application of special elements which we shall call wire grids Drawing a wire grid really means drawing a frame rectangular in XZ YZ QW Editor v 6 5 39 QWED PL Chapter E 2 Graphical editor planes arbitrarily shaped in XY pl
168. rony postprocessing Function returning the value of the next number read from the file defined by OPENF command QW Editor v 6 5 101 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language Function returning the next string read from the file defined by OPENF REDRAW delay Redrawing all the elements on the screen with a specified delay item_type range new_name Changing the name of an element or an object angle x0 y0 Reflecting all the marked elements or objects ROTATE with respect to the specified axis of symmetry by a specified angle SECTION level height height2 Start of section frame medium _name element_ name SETATTR which attribute attr value 1 Sets a property for element attr_value2 SETOBJMED obj name med name Change object material SETPEN colour R colour G colour B Defines the pen colour line width and style for width style drawing the elements marked with the MARK command SETSUSPFLAGS draw suspended Sets internal QW Editor flags skip EXPANDMESH slicing phase SHIFTM dx dy dz Shifting all the marked elements or objects low_ freq upper freq Activates SK1 differential postprocesing freq step assumptions SLICINGPHASE Function returning 0 when QW Editor is in the DRAFT phase and 7 when QW Editor is in the FINAL phase low_ freq upper freq Activates Smn differential postprocesing freq step assumptions mode IterForS Xi
169. s a result we can create structures of complicated shapes and also observe the consecutive phases of the creation even in the form of animation Example at the end of this section shows a process of making a hole in a block of teflon QW Editor v 6 5 90 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language We define a block and a tool Then we move the tool into the block make the hole using JOIN operation and we delete the tool The syntax of the UDO language commands related to moving copying and joining elements or objects e MARKF lt item _type gt lt range gt lt command gt This command is used to Mark or Unmark elements or objects as Passive or Active for subsequent JOIN operation lt item_type gt subject to operation ELEM elements ELEML local elements those created in the currently open object OBJECT objects OBJECTL local objects those created in the currently open object lt range gt range of operation name name of a single element or object to be marked ALL all elements or local elements or objects or local objects ALLACTIVE all active elements or local elements ALLPASSIVE all passive elements or local elements LAST last created element or object lt command gt operation ACTIVE mark for join as active element or object PASSIVE mark for join as passive element or object RESET unmark elements or objects e MARK lt item
170. s and functions in alphabetic order Command Parameters Short description ADDLINE Insert line from previous point to point x2 y2 n dx Insert line from previous point x y to point x dx nn I o ADDXYZ Insert contour Insert contour point apex oS Insert line from previous point x y to point a ytdy al x y Z T Move points at level z to position x y if they are in the square with corners x r y r and teat ytt ALLOWHF ro Switch on Heat Flow heat transfer analysis ANGVAR For 2DVcoa circuits sets modal angular variation range 0 99 For 3DP circuits sets phase shift per period CALL path parl par2 parn parx Calling another object to be nested as a pary parz N subobject in the present object CIRTYPE type medium name Sets circuit type and default medium CLOSELINE Insert line from previous point to x1 y1 point of the last NEWLINE CLOSEOBJ a End of object frame CODE Function returning ASCII code of n th char in string COPY Copying the marked element CREATEMESH Forces mesh creation inside UDO file DELETE item type range Deleting element s or object s DIAMETER dia Declaration of wire diameter allowed only inside the frame of the element declared as WIRE DISPERSION medium name model name Declaration of dispersive dielectric data parl par2 par3 par4 do eee Keyword for if and while commands ELEMENT level height type medname Start of elemen
171. s any errors of analysis at the output wrong port definition wrong template and so on may strongly influence also the S calculation Prony method settings refer to the optional QProny software module Basically it reduces the computing time for circuits with sharp features in the frequency domain such as narrow band pass filters This is achieved by supplementing the Fourier transform calculations naturally following time domain evolution of signals which are physically slow in high Q cases with a digital signal processing by Generalised Pencil of Function Method It allows one to extract the essential features of time signature based on the analysis of time samples obtained at the initial simulation phase For details consult a separate QProny manual QW Editor v 6 5 62 QWED PL Chapter E 2 Graphical editor NTF background shows current settings of the surrounding medium parameters permittivity permeability conductivity and magnetic loss which will be used by the Near to Far calculations They can be modified with Draw Get Libltem command applying elib actions ntfbkg Parameters of the NTF background must be the same as respective entries seen for the surrounding medium in Parameters Media dialogue QW 3D does not check the consistency between the settings made here and those in Parameters Media Inconsistent settings will lead to physically inconsistent postprocessing results For examples of application refer to Section UG 2 3 6
172. seg3 a frame OPENOBJECT name CLOSEOBJ All the objects or elements generated within this frame will belong to an object name For example let us draw verstepa udo with default parameters including the name vrs in an empty project and press Select Object On QW Editor v 6 5 74 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language the displayed list we will see that there is one object of the type udo named vrs When this object is highlighted we can press over Info to verify that it includes three nested objects segl seg2 and seg3 This is correct since those objects were generated by CALL commands within the frame of vrs Double click over vrs name on the object list brings up the header of verstepa udo where we can change its parameters Note that highlighting for example object segl and pressing over Info brings the information that seg contains two other objects segldiel and segicenter since Cxv1d udo used to generate seg7 included two calls to other UDOs However all the objects listed in our project except for vrs are marked as of the type normal which means that they are nested objects and we cannot change their parameters from here They can be selected marked moved and even deleted but their parameters are not accessible from this level o marks a comment line All commands from to the end of line will be neglected by QW Editor s Object Generator Syntax of introduced UDOs commands e PAR l
173. source Lumped source probe load Transmission line source Transmission line load Absorbing wall Perfect matching layer Symmetry plane electric Symmetry plane magnetic Mesh snapping plane Neutral mesh snapping plane Suspended mesh snapping plane Connections between subcircuits Subcircuit box Reference plane NTFbox Plane wave box Electric contour Magnetic contour FD monitor Subgridding box Subcircuits border Lumped impedance lt activity gt activity direction of port UP positive direction of axis DOWN negative direction of axis QW Editor v 6 5 86 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language NONE port without activity lt name gt max 7 characters name of port lt reference gt max 7 characters name of the associated port reference for I O port I O port for reference NULL for I O ports without reference planes e PORTPAR K lt size gt lt size gt lt activity gt lt activity gt lt port_plane gt lt port circumf gt Sets mesh snapping and mesh enforcing properties of the port similarly as the Advanced features dialogue called from the I O ports dialogue lt size gt maximum cell size in the negative direction starting from the port plane lt size gt maximum cell size in the positive direction starting from the port plane lt activity gt 0 or 1 if 1 lt size gt is active lt activity gt
174. structions is ended with semicolon should be the basic procedure of the UDO script debugging o One line of the UDO script can contain several instructions separated by semicolons o The carriage return sign can be brake an instruction into two or more lines However it cannot break the names of commands parameters and variables o UDO interpreter is case sensitive it differentiates between upper and lower case characters QW Editor v 6 5 75 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language o UDO not containing OPENOBJECT name CLOSEOBJ frame is valid and can be drawn However it cannot be modified since its name does not appear on the Select Object list o UDO with more than one OPENOBJECT name CLOSEOBJ frame will be correctly drawn for the first time However it will not be possible to modify it correctly Thus such a structure should be treated as incorrect E 3 3 Defining elements combined elements and materials Let us consider examples threeel udo presented below comment example of three elements bitmap threeel0 bmp PAR name oname 3el PAR length a 6 PAR width b 5 PAR height of first elem h1 5 PAR height of second elem h2 7 PAR height of third elem h3 3 PAR shape ratio top bottom sr 0 5 PAR medium med air ENDHEADER TEST a gt amp amp b gt amp E h1 gt 0 E amp h2 gt 0 amp amp h3 gt 0 Dimensions s
175. sume that the typical way of introducing ports in UDO scripts is by calling one the port UDOs They are available in the standard libraries ports in the form of objects and elements in the form of elements not assigned to any object QW Editor v 6 5 84 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language But it is also possible to introduce ports using directly the primitive UDO instructions In such a case we will proceed in a similar way as when introducing ports directly from the QW Editor Here are the basic hints about it There are two types of ports vertical and horizontal When drawing a vertical port we set its height and draw just one line base of element Let us look at such a port described in UDO language PORT z H INPTEMPLATE UP input rinput NEWLINE x W y x W y NEWLINE x y x y ENDPORT First we declare the port at the level z having the height H It is a source of the type transmission line which in UDO language is described by the declaration of the type INPTEMPLATE Then we declare its activity UP meaning that the energy is supposed to flow in the direction of increasing values of X or Y coordinate We specify also the name of the port and the name of the corresponding reference Next we define the line being the base of the port There is also another line which follows This second line is interpreted as a declaration of two points inside the port The first point shows the place of
176. t description gt lt name gt lt default value gt where lt description gt max about 70 characters of parameter description If the description contains operator chars the text has to be delimited with apostrophes lt name gt case sensitive name of parameter which can be used in expressions within the body lt default value gt initial value for parameter it can be a number or string Function PAR can be used in the header only e TEST lt logical expression gt lt message text gt lt logical expression gt expression which should be true lt message text gt text displayed if logical expression is false e CALL lt path gt lt parl gt lt par2 gt lt parn gt lt parx gt lt pary gt lt parz gt lt N gt lt path gt path to udo file for nested object the path is indicated with respect to the root directory of elib lt par1 gt lt parn gt n parameters of nested object in the place of each parameter we can put a value a variable or an arithmetic expression lt parx gt lt pary gt lt parz gt origin of nested object lt N gt number of parameters of this CALL excluding lt N gt N n 4 Additional remarks o semicolon is a very important separator All instructions with a few exceptions specifically described later in this Chapter must be ended with semicolon Its omissions produce errors of interpretations of the UDO scripts Thus verification if each of the in
177. t each udo file contain a description of one User Defined Object The UDO language is simple and yet gives the user the possibility to create his own arbitrarily complicated parametric objects best suited for his particular requirements It should be noted that QW ObjectGenerator is incorporated into the QWV Editor This means that while inserting a new object or modifying the existing one the user introduces its parameters via a dialogue window which automatically appears in QW Editor Also any User Defined Object interpreted by the QW ObjectGenerator naturally appears in all open windows of the QW Editor This Chapter describes the syntax of the UDO language explains the structure of UDO programs and contains several examples of User Defined Objects which are also included on the installation CD of QW 3D E 3 2 Structure of a single UDO and calls to other UDO s Let us consider a very simple UDO script verstepa udo which can be found in the directory elib examples It is a simplified version of verstepo udo considered in the example of Section UG 2 8 2 In QW Editor after clicking over a choosing the library examples clicking with the right mouse button over the object verstepa and choosing Edit UDO we obtain a display of the UDO script as shown below comment Vertical coaxial line with impedance step bitmap verst0 bmp PAR object name oname vrs PAR inner dia ind 3 04 PAR outer dial oud1 7 QW Editor
178. t frame name spin wire ENDELEM Se End of element frame ENDHEADER Separates header and body of the UDO program endif _ Ba ifcormmanc ENDPORT __ End of port frame ENDSECTION Endof section frame fendwhile __ Ends white command EPSEFF value Port effective permittivity setting QW Editor v 6 5 99 QWED PL Chapter E 3 EXPANDMESH FDPROB FDPROBPAV GETIOPAR GETMESHPAR GRIDHV INSERTMEDIUM JOIN LOSSES LUMPED LUMPIMPPAR MARKFJ MEDIUMCOL MEDIUMPAR MESHINDEX MESHX MESHXINDEX m O QW Editor v 6 5 Syntax of the User Defined Object UDO language solutions f0 iterations Enables eigen value solver lowerlevel upperlevel Expands mesh limits in z direction lower_freq upper freq Enables frequency domain probing freq_ step lower_freq upper_ freq Enables frequency domain probing for power freq_step available from the source file name The I O port parameters are read from the file Function returning the n th mesh parameter orientation h orientation v Declaration of wire grid allowed only inside the frame of the element declared as WIRE name type Inserts a medium into the project operation CUT INTERSECT GLUE Joining elements text string Controlling losses suppression and metal loss bandwidth component options Parameters of lumped port impedance type component Rp Lp Cp Parameters of lumped impedance Rs Ls Cs item _
179. t level settings please use Setup Level command There are two basic shapes of the element s base o Rectangle To draw a rectangle please click the left mouse button two times to mark its comers QW Editor v 6 5 34 QWED PL Chapter E 2 Graphical editor o Circle The circle is approximated by a regular polygon with the number of sides sectors defined by the user A high number of sectors gives better accuracy but slows down the QW Editor operations The choice of the number of sectors gives also a possibility of using the Circle command to introduce arbitrary polygons For example if we want to introduce an irregular octagon we first define a circle with 8 sectors and then use Edit Point command to move each of the corners of the octagon to its proper position Note that the height can be set to zero However an element of zero height and medium other than metal will be ignored An element of zero height and metal medium models by default a thin metal patch However starting with version 2 0 this default can be changed so that the element will model a grid of wires located in the XY plane see Section E 2 2 7 for details QW Edit IN AIR O x Wien Draw Edit Setup Info Help 7 Undo az A TO crdejpoyon E E amp SE SO IEA feds Senki Rectangle P Element l Comment Line P Combined 2 Methanol Circle pal iF Bi phased Element Rectangle 3 Circle palygon fF Bi phased Combined J Circle p
180. tGenerator 13 73 90 QW Optimiser 72 73 QW OptimiserPlus 72 73 98 QW Simulator 6 14 15 17 49 53 60 64 105 radiated power 6 radiation efficiency 6 radiation patterns 6 36 61 reference plane 31 44 46 47 48 50 60 86 SAR 22 64 Setup group of commands 21 shortcuts Ctrl A 17 Ctrl S 17 Ctrl T 17 Ctrl Y 39 Ctrl Z 39 E 28 30 K 28 34 45 S matrix 5 46 47 60 62 S parameters 6 9 47 48 52 61 Specific Absorption Rate SAR 64 tasker file 6 70 105 TEM mode 54 template generation 48 85 toolbar 2D window 38 QW Editor 17 Tools group of commands 13 UDO 73 85 88 90 96 99 UDO commands 77 99 ADDLINE 77 79 81 ADDX 77 79 ADDXYZ 79 ADDY 77 79 ADJUSTP 80 ALLOWBHM 90 ALLOWHE 90 ANGVAR 90 CALL 74 75 97 CIRTYPE 90 CLOSELINE 77 79 CLOSEOBSJ 74 76 CODE 82 COPY 92 CREATEMESH 96 DELETE 92 DIAMETER 79 DISPERSION 79 QW Editor v 6 5 110 ELEMENT 77 78 ENDELEM 77 78 ENDHEADER 74 ENDPORT 86 88 ENDSECTION 80 EPSEFF 87 EVS 90 EXPANDMESH 95 FDPROB 89 GETIOPAR 86 87 88 98 GETMESHPAR 96 GRIDHV 80 INSERTMEDIUM 79 JOIN 91 LOSSES 90 LUMPED 87 LUMPIMPPAR 87 MARK 91 92 93 MARKFY 91 MEDIUMCOL 79 MEDIUMPAR 77 79 MESH 95 96 MESHINDEX 95 96 MESHPAR 96 MESHX 96 MESHXINDEX 96 MESHY 96 MESHYINDEX 96 MIRROR 92 MIRRORX 92 MIRRORY 92 MIRRORZ 92 MODE 88 MTEM 88 NEWLINE 77 79 81 85 NTF 89 NTFBKG 89
181. ted The colour assigned to a particular element is used for its display in all windows It can be changed in 2D QW Edit window of QW Editor only movetoa2D QW Edit window e invoke Edit Select Element command and choose the element in question press the right mouse button to get the Change element menu press Pen to enter Select Pen dialogue and choose a new Colour note that Style and Width chosen in the same dialogue apply to 2D window only confirm new settings with OK buttons An alternative to 3D window solid view display resides in using HOOPS 3D Viewer The Tools SAT Viewer command opens the viewer transforms the current project description into a format recognised by the viewer and loads it We can then use the rich menu of the HOOPS 3D Viewer options to display and rotate the 3D image of the designed structure E 2 4 Drawing and editing ports E 2 4 1 Drawing I O Ports and reference planes As it has been shown in Chapter UG 2 or V2D 2 of the manual in most practical application we can use predefined library UDOs to draw appropriate ports This section describes the procedure for drawing ports in an alternative manual way In fact the commands which can be found in the scripts of the port generating UDOs fully correspond to the manual procedures described below After invoking the command Draw I OPorts we get a dialogue window presented in the upper part of Fig E 2 4 1 1 QW Editor v 6 5 44 QWED
182. ter E 2 Graphical editor Edit 1 0 port E 2 x Mame temp MHo f EscEdit Shift Fort type input Template y Delete Fort height Poo y Z Activity Minus Shap mesh to Set plane k W port plane F port circumference F 26 768 76g Forced cell size Mirus fo o Pen Cancel Pls fo Parameters re Fig E 2 2 2 3 Edit I O port dialogue window e Edit Line Invoking this command and then pressing the left mouse button selects a line defined at the current level with centre closest to the cursor position Pressing the right mouse button we see a dialogue window with the choice of several operations Delete _Esckdt Split 10 port Electric Fig E 2 2 2 4 Line change window o Delete eliminates this line from the contour of the element o Split produces an extra point in the middle of the line The position of the new point can be changed using Edit Point command o Close abandons the currently selected line but we remain in the Edit Line mode with square cursor and can select another line o Esc Edit abandons the currently selected line and abandons the Edit Line mode cursor returns to arrow o Electric is active only for lines perpendicular to either x or y axis It defines a mesh snapping plane of Electric type along this line o I O port is active only for lines perpendicular to either x or y axis It invokes the same dialogue as the Draw I OPorts command However
183. type range command Used to Mark or Unmark elements or objects for further operations of movement or reproduction item_type range command Used to Mark or Unmark elements or objects as Passive or Active for subsequent JOIN operation medname pen R pen G Material pen brush colour style setting pen B pen style pen width brush pen R brush pen G brush pen B brush bkg R brush bkg G brush bkg B brush style medname epsx mux sigx Material parameters setting msigx psy muy sigy msigy epsz muz sigz msigz density n Function returning the z level of the n th sublayer of the FD TD mesh level Function returning the ordinal number of the sublayer of FD TD mesh situated at or below level argl arg10 Permits to make global mesh settings n Function returning the x coordinate of the n th mesh line of the FD TD mesh level Function returning the ordinal number of the border between FD TD cells at or below level in X direction 100 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language MESHY n Function returning the y coordinate of the n th mesh line of the FD TD mesh MESHYINDEX level Function returning the ordinal number of the border between FD TD cells at or below level in Y direction MIRROR xy XZ YZ Performing a mirror reflection of all the marked elements or objects with respect to the planes z 0 or and y 0 or and x 0 MIRRORX xmirror Per
184. uggestion to AMIGO to limit the automatic mesh refinements in such a way that too small cells are not generated Very small cells may have a strong effect on computing time Not only the total number of cells increases but also the FDTD step in time is automatically adjusted The box with lt sign allows to set a relatively reasonable default value when the user is not sure what initial value should be introduced In particular it can be used when the software has no hints about Imin and displays value in red Attention setting Imin higher than amax should be considered as inconsistent and may produce somewhat confused reaction of AMIGO The software also displays information about three other parameters which depend on the above user s choices They are the cell size in air corresponding to the chosen number of cells per QW Editor v 6 5 10 QWED PL Chapter E 2 Graphical editor wavelength at the highest frequency in the chosen range f2 the current number of FDTD cells in the project and the smallest cell size in the current FDTD meshing In general the smallest cell size should not be smaller than half of the cell calculated for the frequency f2 in the medium of the shortest wavelength and not smaller than half of Imin set by the user If it obeys above conditions it is displayed in green Otherwise it is displayed in red suggesting that some details of the geometry or mesh snapping planes explicitly enforced by the user mak
185. ular frequency In this case we use the sinusoidal waveform Note that since the sinusoidal excitation can provide the S parameters only at one frequency and since the simulation with such an excitation is not faster than with the pulse it is never used for S parameter analysis In the case of quasi TEM lines we can often predict that there will be no resonance within the frequency band quite above the band of interest In such special cases it may be better to set f higher than the upper frequency of interest since this will reduce the absolute duration of the pulse and speed up the convergence Two other parameters seen in the considered dialogue window are amplitude and delay of the signal They are irrelevant for the S parameter calculations They may be important only for visualisation of the effects of concurrent multi port excitations or for simulation of nonlinear e g temperature dependent effects Note that e Incase of template excitation there is a direct correspondence between waveform amplitude and power available from the source For amplitude set to unity power available from a sinusoidal source is 1 W at the source frequency while power available from a delta source 1W wide band For other waveforms available power varies with frequency and equals unity at the centre of the band The FD Pavailable postprocessing shows the available power versus frequency Increasing amplitude by a factor of A means increasing the ava
186. um while the element B as filled outside by this or other medium Intersecting elements must be treated by the Edit Join operations These operations produce out of them new elements that are non intersecting If the intersecting elements are still present during the mesh generation by QW Editor the mesh generator may not treat them in accordance with the user s intention The resulting analysis will then be erroneous as exemplified in the example of Section UG 2 12 1 In general it cannot be avoided that it is the user s responsibility to provide consistent data to the editor and thus to eliminate intersecting elements before performing Export Note that according to the above definition if an element is internally tangential to another one it should in general be treated as intersecting However some of such situations described in Section UG 2 12 2 are automatically detected by the QW Editor and treated correctly without the Join operation Note In case of any doubts if the geometry of the project was correctly defined by the user and correctly understood by the mesh generator we strongly recommend to verify the meshing results using Test Mesh option of QW Simulator extensively used in examples of Section UG 2 12 and described in Section S 2 6 Multiple filled cells As it was mentioned above QW Editor creates and exports to QVV Simulator a conformal mesh that may include cells filled with two different media two dielectrics or meta
187. urce or probe should be connected to the metal elements with additional wire elements It is also possible to place a point source or probe directly on the wire This feature will be particularly convenient in the analysis of wire antennas changes in the meshing will not need to be associated with changing the size of the gap to keep it equal to one FDTD cell The Lumped source probe port placed on the wire will cut a gap in the wire and work directly in that gap If a lumped source probe is included in the S parameter postprocessing its resistance R serves as a reference resistance for separating the incident and reflected waves However if R INF or R 0 then 50 Q is taken as a reference Note that FD Probing postprocessing also produces reflection loss as one of its results It is denoted by a symbol S_number where number is the value of R Here S_number is not calculated if R INF or R 0 Postprocessing part of the dialogue allows specifying in which postprocessing algorithms the Lumped source probe port should take part e FD probing stands for frequency domain probing and means that Fourier transforms of terminal voltage and current will be calculated e S as port No includes the Lumped port in the S parameter extraction system together with Transmission line ports e Transmission line describes a port defined by integrals of fields over a cross section of an arbitrary transmission line In such a case we are always i
188. xplicit setting the forced cell size will be inherited from the settings of other special planes and it will be shown in brackets If the forced cell size has been explicitly defined for two special planes located in the plus and minus direction from the considered plane respectively the forced cell size for this considered plane will be calculated by linear interpolation This opens way to the construction of a linearly varying mesh Remember that the edges of the circuit take part in the algorithm if the Edges force linear mesh box is checked In the upper right part we get minimum values of the distances between the neighbouring special planes versus minimum cell size in each direction If the distance between special planes is much smaller than the cell size declared in the window of Fig E 2 2 1 10 and in particular if it is equal to the minimum cell size in a particular direction the software will introduce there a relatively small cell and reduce the time step to assure stability on this small cell This will significantly slow down the process of the analysis To warn the user about the existence of such closely situated special planes they will be marked in 2D windows by red points at the external contour of the grid In the lower right part of the Info Mesh window we can see how many cells have been created in the QW Editor and how many of them will appear in the QW Simulator including the cells needed to model the boundary effects
189. yntax of the User Defined Object UDO language ENDELEM REDRAW 3000 MARK ELEM tool RESET eae ad Oe MARKEJ ELEM tool ACTIVE eet MARKEJ ELEM block PASSIVE SHIFTM 0 b 2 5 0 JOIN CUT REDRAW 3000 REDRAW 3000 MARK ELEM tool RESET seated te a MARKE ELEM tool ACTIVE aL MARKFJ ELEM block PASSIVE CLOSEOB JOIN CUT REDRAW 3000 DELETE ELEM tool CLOSEOB Note Please use the project Standard Toollemptyex pro to execute examples tool udo in QW 3D This project is empty but has the windows prepared for good visualisation of the executed operations an Add Object C Program Files QWED QW_3D e0 enNm lt Ed Puan vate Block engihiea h2 Blok with ci ho Blok heihtied Tool width x dir Teal horizontai pos yi2 Cancel Description Tool acting with a block E o y y oz Fig E 3 7 1 Tool object dialogue right and three phases of the object creation as seen in the QW Editor QW Editor v 6 5 94 QWED PL Chapter E 3 Syntax of the User Defined Object UDO language E 3 8 Biphased element and objects QW 3D only Biphased objects are composed of biphased elements or and are drawn differently dependent on the phase DRAFT or FINAL of QW Editor Let us recall that in Section E 3 3 we considered three possible types of monophased elements lt type gt type of element 0 simple element 5 bottom of combined element 6 cover of combined element Bi

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