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Spice Line - User's Guide

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1. 26 Line parameters Number Desires tesi eee ee Be eee ee Be ew Bee Bw eA ee 26 Line sparaimeters EAan SCOMetry poogt gee cars ents nr et a Eaa ne er nha E EO eh tete te 26 Line parameters Select change of variables 26 Line parameters Edit input matrix 26 Line parameters Edit input matrix L 26 Line parameters View output matrix 26 Line model Compute eigenmodes 26 Eine model View modes scr sui arin rk eat kd ee coed ay aed licks pets oad Na ed oh hed ay le 27 Line model Compute Spice models 27 4 6 Example 2 solving an emission problem 27 Line parameters Select change of variables 27 Radiated fields Describe position 29 Radiated fields Select excitation and compute 29 5 References ti LE 5 455 Ge base E E An 6 A SE RE Ade gee 6 ee ut 30 Os INIER epr naD E ae ee ete ae ee ned eee RRL hes eats eee OA owe 31 7 Appendix Results obtained with Example 2 31 Document 00012107B page 2 1
2. CONSULTANTS SPICE LINE 2 23 with Telecom Line Predictor User s Guide March 2000 Table of Contents 2 1 SpiceLine and the SpiceLine User s guide 3 2 What is SpiceLine 5 3 Theory of operation 7 4 Getting started 21 5 References 30 6 Index 31 7 Appendix Results obtained with Example 2 31 This document includes 39 pages EXCEM 12 Chemin des Hauts de Clairefontaine 78580 MAULE tel 33 1 34 75 13 65 web site http www excem fr fax 33 1 34 75 13 66 Document 00012107B fichier tram36 maspli2e wpd page 1 TABLE OF CONTENTS 1 SpiceLine and the SpiceLine Users guide Laisse de a oe ES Rs Se ne 3 AMES TEESS Coy vi uc pees ene tee er E CO T a a a Oa E Re A A AAAA A AA E T 3 1 2 This User s guide copyrights trademarks 3 1 3 Terms of sale warranty license for the SpiceLine software 4 1 4 Updates and printing History steam ramener Rad stad edad eda edakedene dane see 4 2 What AS IGE ESTES ES Jae sar ols Re APR OD Ges WOR GOR SO OS EG ew Oe 5 2 1 A software for emission immunity and crosstalk predictions 5 2 2 Description of the transmission line and crosstalk predictions 2 3 Capabilities of SpiceLine emission predictions 6 2 4 Capabilities of SpiceLine immunity predictions 6 Se LHCO
3. bids45 dll bivbx11 dil owl250 dll vtssdil dil vtss vbx 4 1 4 Disk 3 The floppy disk3 contains the files bc520rtl dil bivbx1 1 dil owl52 dll 4 1 5 Disk 4 The floppy disk 4 contains files in the root and in four other directories exemples for_sn for_pr for_cir Document 00012107B page 21 The root of floppy disk4 contains the files describing several changes of variables see 3 3 ident cov stpla cov stplb cov stp4a cov stp4b cov utpla cov utpib cov utpda cov utp4b cov The directory examples of the disk4 contains SpiceLine files for 5 SpiceLine projects IEEE0296 UTPDI UTPD8 STPD1 STPD8 The file names of the file belonging to these projects are made with the name of the project and the following extensions pjt inc inl inr ouc oul our cva cvb erc erl err project file containing general information on the project file containing the input capacitance matrix file containing the input inductance matrix file containing the input resistance matrix file containing the output capacitance matrix file containing the output inductance matrix file containing the output resistance matrix file containing the A matrix file containing the B matrix file containing the error report on the output capacitance matrix file containing the error report on the output inductance matrix file containing the error report on the output resistance matrix for a total of 70 fi
4. v V v vs L 4 4 V v v v i ere 22 5 2 1 2 2 3 4 5 2 1 2 2 3 4 1 1 1 Dr pis Se Ve ut I Gti 3 is i 1 1 Lz e Re n T 7 it tig Fla i I i m The stpla cov and stp1b cov are respectively a A matrix and a B matrix for a STP cable with one pair The transformations are RE V v I a aE 2 i Va Ys i 1 23 V v I i i i m The stp4a cov and stp4b cov are respectively a A matrix and a B matrix for a STP cable with four pairs The transformations are Document 00012107B page 12 1 V v v gt V v V L Let V v v v v 2 hire Wo L 56 i 56th Ga 15 Diko ues I lit ti 36 i 1 3 L i t ti i i eue ra o nil s I i i 1 V v fick A UNE I i i i 3 4 Additional features for twisted pair cables change of cable height The Telecom Line Predictor of SpiceLine offers a model for implementing a modification of cable height above a ground plane The modifications apply only to the Ly and Cy matrices of a STP cable for a transform having the following properties property 1 all elements of the last row of the B matrix have the same value property 2 for any row of the A matrix but the last line the sum of all elements is zero We note immediately that the transformation defined by 14 to 17 have these two properties If h is the reference height that is to say the height g
5. 3 of 4 2 under the name pscirc open a ICAP 4 simulation for pscirc cir in SpiceNet change the subcircuit name of the cable for psid give the appropriate line length and in the Edit Control dialog add INCLUDE MYCABLE LIB Document 00012107B page 28 m Simulate this circuit m Start SpiceLine again and use File Open project to select the trial2 pjt project m Use Radiated fields Describe position to specify the line length the coordinate X Y Z of the point at which the fields will be computed and the abscissa Zx at which the last element V and vectors will be computed see 3 8 m Use Radiated fields Select excitation and compute and select name OUT for instance pscirc out The calculation begins first with the calculation of J and V then with the calculation of the radiated fields E and H The results can be saved after the calculation is completed into a file result OUT that will contain the field values and the current and voltage values as a function of frequency This file can be viewed in a text editor or used in the IntuScope post processor of the ICAP 4 Windows package Please note that this example is built with the STPD1 SpiceLine project and with stplp1 SPICE project which originally implements the ST12E model see 4 1 5 The result obtained with these projects are shown in Appendix A Document 00012107B page 29 5 References 1 F BROYDE E CLAVELIER C HYMOWITZ Simulation
6. SpiceLine and the SpiceLine User s guide 1 1 SpiceLine SpiceLine 2 23 with Telecom Line Predictor usually called SpiceLine later on is an easy to use software for multiconductor transmission line modeling It can be implemented with any Spice 3F 2 compatible simulator but it is best suited for the ICAP 4 Windows version 7 x simulation package edited by Intusoft because of the parameter passing syntax choosen in SpiceLine SpiceLine is edited by Excem a company specialized in EMC and in the design and simulation of electronic circuits The copyrights of SpiceLine are owned by Excem and SpiceLine is a registered trademark of Excem 1 2 This User s guide copyrights trademarks This User s guide contains most information needed to understand how to use SpiceLine and what are the definitions we use for the parameters describing the multiconductor transmission line problem It contains a theoretical presentation and implementation examples Another document the Reference manual contains a detailed description of every features of SpiceLine Note that this User s Guide is not a tutorial on EMC nor on multiconductor line modeling and we will refer to the available litterature when appropriate Numbers between square brackets like 1 indicate one of the references listed at 5 This User s guide is edited by Excem Copyright Excem 1998 2000 Electronic Edition Excem 2000 All rights reserved No part of thi
7. V1 39 1 END 27 Feb 00 17 42 Page 1 Page A2 Result of todB of V 3 50 00 70 00 90 00 110 0 130 0 100K 10MEG WFM 1 V 3 vs FREQUENCY in Hz Common mode voltage Page A3 Result of todB of I V3 50 00 70 00 90 00 110 0 130 0 fi 100K WFM 1_1 V3 vs FREQUENCY in Hz Common mode current 10MEG Page A4 Result of todB of V E 40 00 20 00 20 00 40 00 WEM 1 V E vs FREQUENCY in Hz Radiated electric field Page A5 Result of todB of I B 10 000 30 00 50 00 70 00 90 00 WEM 1 I B vs FREQUENCY in Hz Radiated magnetic field Page A6 Result of todB of V X 40 00 80 00 120 0 160 0 200 0 10K 100K 10MEG WEM 1 V X vs FREQUENCY in Hz Current induced by an electric dipole Page A7 Result of todB of I Y 10 000 30 00 50 00 70 00 90 00 WFM 1_ I Y vs FREQUENCY in Hz Current induced by a magnetic dipole Page A8
8. a small magnetic dipole made of a circular loop of surface S at the point P we know that the voltage induced in this dipole by the fields produced by the current Zy is Voi JOM Sy U Hp 36 where u is a unit vector orthogonal to the plane of the loop Let us now assume that we replace the current source which produced the current Z with an open circuit and that we measure the voltage V across this open circuit with the sign convention of generator associated with the sign convention choosen for measuring If we install a current source sourcing a current into the electric dipole measured with the generator s sign convention associated with the sign convention choosen for measuring V the reciprocity theorem tells us that we will measure V 1 u H Vp LEE jou EM 37 T1 T1 where M Mu is the magnetic dipole moment measured positive in the direction of u Document 00012107B page 18 If one creates a SPICE simulation for computing the electric field H p radiated for J 1 A SpiceLine will compute in this manner the voltage V induced by a magnetic dipole with an amplitude of 1 Am case c current induced by an electric dipole Let us consider the emission by radiation of a cable excited at the near end termination by a unique voltage source delivering the voltage Vy With the method and the limitations presented at 3 8 we are able to compute the electric field E p and the magnetic field H p at a given
9. cable symbol in SpiceNet Note that for the SPICE model just created the utplp sym model included in Spice SN S YMBOLS S YMSPLNE is appropriate Following the appropriate steps you can also edit the new library by adding appropriate SRC and S YM lines to each model see the supplied spIne223 lib library then compile a new data base and thus become able to access your models created with SpiceLine in the SpiceNet Part X part Browser window 4 6 Example 2 solving an emission problem The possibility of solving an emission by radiation problem is now implemented in SpiceLine when suitable changes of variables have been implemented see 3 8 m Use File New project to create the project trial2 pjt m Use Line parameters Number n to specify the number of conductor in the cable including shields Select n 3 for a multiconductor transmission line with two conductors and an a shield above a ground plane m Use Line parameters Line geometry for specifying the reference height for which the inductance capacitance and resistance matrices that you are going to enter have been established note that this is a STP cable and the nominal height for which the calculation will be performed could therefore be different from the reference height in other words you can use the tools for modifying the matrices described in 3 4 In the present case you can leave the nominal height and the reference height to 0 1 m m Use Line parameters Sele
10. lossy transmission line SPICE model which defaults to 1 Document 00012107B page 10 3 3 Additional features for twisted pair cables change of variables The Telecom Line Emission Predictor of SpiceLine offers the possibility of implementing a transformation i e a change of variables for the L C and R matrices Twisted pair cables are designed for symetry If their symetry was ideal and if they were implemented with perfectly symetrical terminations they would not have any crosstalk nor any emission It is therefore essential to take their deviation from perfect symetry into account Unfortunately these deviations are accounted for by tiny differences between elements of the L and C matrices It has been shown in 3 that a convenient way of measuring or describing these deviations from symetry is to implement a transformation on voltages and currents In that case instead of entering the L C and R matrices of the cable one will enter the transformed matrices Lr Cr and Ry matrices Let us number the conductors of the cable in the following manner conductor 1 conductor 1 of pair 1 conductor 2 conductor 2 of pair 1 conductor 3 conductor 1 of pair 2 conductor 4 conductor 2 of pair 2 etc In the case of a UTP unshielded twisted pair cable with p pairs we can thus number the n 2p conductors of the cable In the case of a STP shielded twisted pair cable with p pairs we in addition give the number n 2p 1 to the cable
11. shield Let us note i 7 the currents flowing into the conductors 1 to n of the cable measured at a given distance z from the near end of the cable and i the corresponding column vector Let us note Va the voltages of the conductors 1 to n of the cable measured at the same distance z from the near end between each conductor and the reference conductor and v the corresponding column vector Let us note J Z the transformed currents and I the corresponding column vector Let us note V Va the transformed voltages and V the corresponding column vector The transformed current and voltages are defined by the transformation matrices A and B V Av 19 I Bi whence the transformed inductance resistance and capacitance matrices are respectively L ALB R ARB 20 C BCA SpiceLine allows that the user introduce two changes of variables one for the currents and one for the voltages The changes of variables are defined by specifying a A matrix and a B matrix Four pre defined A matrices and four pre defined B matrices are also provided in Spice Line m The utpla cov and utp1b cov are respectively a A matrix and a B matrix for a UTP cable with one Document 00012107B page 11 pair The transformations are Aa 1 i i 2 21 Vee GY L i i m The utp4a cov and utp4b cov are respectively a A matrix and a B matrix for a UTP cable with four pairs The transformations are 1 G V v
12. the characteristic impedance matrix etc see 3 2 Document 00012107B page 26 m Use Line model View modes if you wish in order to inspect the computed quantities You can compare them with those obtained in 1 for the symetrical case m Use Line model Compute Spice models for storing the SPICE model You can choose an existing name lib file in which case the new models will be appended to the library file or create a new one Type mycables lib as file name Select L an M and D and E models with names like pull pulm puld and pule in the four Name boxes Select Add You just added four models to the mycable lib library file file of Sline files This library mycable lib should now be copied in the PR directory Spice PR or Spice4 PR in order to be used by the ICAP 4 SPICE simulator You are done The new SPICE model can be directly used with ICAP 4 Windows version 7 x for the simulation of crosstalk problems provided a suitable INCLUDE MYCABLES LIB is inserted in the File Edit controls window of SpiceNet The length of the cable is the L parameter note this is not an inductance If you wish to implement them in a convenient way you may choose to manually associate these models with proper SpiceNet symbols which you can call with the Draw Get symbol window of SpiceNet These actions are documented in your ICAP 4 documentation The length of the cable can in this case be specified using the L parameter of the Label dialog of the
13. where B element refers to the non linear dependant source of the Spice 3F 2 syntax Losses can also be included in any of those models 1 e the resistance matrix can be taken into account The inductance capacitance and resistance matrices are considered frequency independant The models created by SpiceLine can be copied into any existing or new SPICE library If the models are meant to be used with ICAP 4 Windows no further editing is required because SpiceLine and ICAP implement the same parameter passing syntax for the line length in meter In addition to the models themselves SpiceLine users have also access to some additional information on the computed quantities related to the eigenmodes of the line the propagation velocities vector the transfer matrices the characteristic impedance matrix The Telecom Line Predictor of SpiceLine offers several important additional features Entering line parameters inductance capacitance resistance not referenced to ground by accepting user defined change of variables for inputs Document 00012107B page 5 Modifying the line parameters with a model suitable for taking into account a modification of a shielded cable height above a ground plane This Telecom Line Predictor is what is needed for a proper treatment of multipair cables The SPICE models so obtained can be used for AC or TRAN SPICE simulations using accurate circuit models of the transmission line terminati
14. Crosstalk and Field to Wire Coupling with a Spice Simulator JEEE Circuits and Devices Vol 8 No 5 September 1992 pp 8 16 2 F BROYDE E CLAVELIER L HOEFT Comments on A SPICE Model for Multiconductor Transmission Lines Excited by an Incident Electromagnetic Field JEEE Transactions on EMC Vol 38 No 1 February 1996 pp 104 108 3 F BROYDE E CLAVELIER O DAGUILLON A ZEDDAM Comparaison de l mission des cablages de t l communication actes du 9i me colloque international et exposition sur la CEM Brest 8 11 juin 1998 pp B5 13 BS 18 Document 00012107B page 30 6 Index cable height 523234 saisies Peed 13 capacitance matrix 7 cartesian coordinate 16 chain supermatrix Le Les Bet ee re 16 change of variables 11 characteristic impedance 9 conditions g n rales de vente 4 conductor numbering 11 cosmetic measure 1 14 cosmetic measure 2 15 node heu Ma oneal can ni tarte 9 PTO GED ia sitas rer Mara mur 9 eigenmodes 2145 eee eee Mure 9 emission by conduction 15 emission by radiation 6 15 Example lt occa oA E sets cea Ms 26 Example 2 cs nus iusto adi ee ed 27 external field sources y ris aw ole Seaway 17 SA Nne a ea a Geen 21 25 general terms of sale 4 IMIMUNILY ae oy a ne te eh ee 6 induc
15. DC resistance of the reference conductor We therefore advocate the practice of adding in the MTL SPICE model an appropriate lumped resistor at one or both ends of conductors potentially subject to this problem Let us call this cosmetic measure 2 The two cosmetic measures proposed are equivalent to artificially adding the whole or part of the DC resistance matrix of the MTL to the lossless model Note also that the cosmetic measures proposed above are only applicable when the added impedance and transimpedance remain much smaller than the corresponding terms of the characteristic impedance matrix of the MTL assumed lossless If this was not the case they would generate a parasitic impedance mismatch in the problem and hurt the accuracy of high frequency coupling calculation Also the shields in the example above are characterized by a per unit length transfer impedance with frequency independant resistive and inductive terms only as is well known this is only accurately valid for some types of screen for instance non optimized single braided shields SpiceLine allows model to be created either with all terms of the resistance matrix taken into account for a model including the cosmetic measures 1 and 2 at each end of the SPICE model a circuit equivalent to the resistance matrix R times the half cable length is added It is also possible to only take into account the diagonal terms of the resistance matrix for a model including the
16. RY OL OPeLallON RSS ER x et BEA cde TN es Re ashe is oe Rice Sie ue ee Bech aoe 7 3 1 The inductance capacitance and resistance matrices 7 3 2 Theory of transmission line modeling with SPICE 8 3 3 Additional features for twisted pair cables change of variables 11 3 4 Additional features for twisted pair cables change of cable height 13 3 5 Sequence of operations on input data 14 3 6 Taking losses into account 14 3 7 Theory of crosstalk problems 15 3 8 Theory of emission by conduction and by radiation problems 15 3 9 Theory of voltages and currents induced by external field sources 17 4 Getting started cise dies wag ae Wad etage ie net an le neue GAS Aa Gg de ep ag ae ot le fast 21 4 1 Initial inspection and parts list 21 42 Installation Lame er acetate aid es ak ala es ares ee ares A AIS AMD eS RD HSS BRN BES AN GED BARS alta TA 24 4 3 Files produced by SpiceLine 25 4 4 Sequence of operations with SpiceLine 25 4 5 Example 1 solving a crosstalk problem
17. SpiceLine for instance with the IntuScope data post processor of ICAP4 Windows If you also want to compute a voltage or current induced by a field source you need to accomplish three steps after step 3 Abis running a ICAP4 Windows version 7 x simulation meeting the requirements of 3 8 Sbis computing the induced currents or voltages with SpiceLine using the namel out file generated by ICAP4 Windows 6bis displaying the results stored in the name2 out file generated by SpiceLine for instance with the IntuScope data post processor of ICAP4 Windows 4 5 Example 1 solving a crosstalk problem m Use File New project to create the project triall pjt m Use Line parameters Number n to specify the number of conductor in the cable including shields Select n 2 for a multiconductor transmission line with two conductors above a ground plane m Use Line parameters Line geometry for specifying the reference height for which the inductance capacitance and resistance matrices that you are going to enter have been established note that this is not a STP cable and the nominal height for which the calculation will be performed must therefore be equal to the reference height in other words you cannot use the tools for modifying the matrices described in 3 4 In the present case you can leave the nominal height and the reference height to 0 1 m m Use Line parameters Select change of variables and select ident cov for the A matrix and the B
18. and the magnetic field H p at a given point P If we now install a small electric dipole made of two aligned segments of length d at the point P we know that the voltage induced in this dipole by the fields produced by the current Zy is Vn d u E 34 where u is a unit vector aligned with the dipole Let us now assume that we replace the current source which produced the current Z with an open circuit and that we measure the voltage V across this open circuit with the sign convention of generator associated with the sign convention choosen for measuring If we install a current source sourcing a current Jp into the electric dipole measured with the generator s sign convention associated with the sign convention choosen for measuring V the reciprocity theorem tells us that we will measure siete of Mis 35 Vio Ir TI where P P w is the electric dipole moment measured positive in the direction of u If one creates a SPICE simulation for computing the electric field E p radiated for J 1 A SpiceLine will compute in this manner the voltage V induced by an electric dipole with an amplitude of 1 Cm case b voltage induced by a magnetic dipole As for the case a let us consider the emission by radiation of a cable excited at the near end termination by a unique current source delivering the current We are able to compute the electric field E p and the magnetic field H p at a given point P If we now install
19. by the per unit length dipole moments M 2h lu 30 P 2hy Cou Vye 31 CM CCM x and where Icy 1 is the common mode current where Vey V is the common mode voltage and where Ccy is the common mode capacitance equal to the last diagonal term of the transformed capacitance matrix BCA The fields are computed as E BauPhu r ux uxr Se dz 0 ror j d d ATE 32 e ffik_ e nye i r wm AT i and ren k er H peu wm re dz 33 L 2 jkr f Eh le dz 0 rr r ATEN The integrals are computed as Rieman sums with a maximum number of terms ranging between 16383 and 32766 As a consequence the calculation will become inaccurate when the line length is not much smaller than 16383 times the wavelength or when the point at which the fields are computed is too close to a very long line 3 9 Theory of voltages and currents induced by external field sources SpiceLine is also able to compute the voltage and current induced on the transmission line by external field sources at a given point in space This computation is based on reciprocity The theory is the following case a voltage induced by an electric dipole Document 00012107B page 17 Let us consider the emission by radiation of a cable excited at the near end termination by a unique current source delivering the current With the method and the limitations presented at 3 8 we are able to compute the electric field E p
20. complished by adding the text splne223 lib at the right spot in SN Lib Spice SN Lib or Spice4 SN Lib using a text editor Document 00012107B page 24 Substep 5 2 with a text editor add the appropriate lines at the end of Spice DBASE SRC Substep 5 3 run SN MAKEDB BAT which compiles an updated SpiceNet database If you want to know more about this six steps procedure please read the Updating the data base entry in your ICAP documentation Please note that we found that the simulator IsSpice version 7 6 delivered with ICAP 4 version 7 6 has a major bug when one directly measures a voltage at the pin of a subcircuit The solutions to this problem are Try to always keep in mind that you should not do that for instance inserting a 0 V DC source solves the problem Or better ask your Intusoft reseller to supply free of charge a simulator delivered with ICAP 4 version 7 51 for instance the simulator IsSpice version 4f3 6 Then save the cml dll real dil and Spice4 exe file of ICAP 4 version 7 6 somewhere if you think you might need them again and install the cml dll real dll and Spice4 exe of the earlier simulator version into the IS directory Spice IS or Spice4 IS For launching SpiceLine use the Windows 95 98 file manager and doubleclick on Spline23 exe 4 3 Files produced by SpiceLine The different matrices used in a project are saved under the following names where filename
21. cosmetic measure 2 3 7 Theory of crosstalk problems Once a SPICE model of the cable is created and implemented into a SPICE simulation software the current and voltages may be computed during the simulation Cable crosstalk is described by the SPICE model which can be used in AC and TRAN simulation with SPICE Usually the emission by conduction also called conducted emission by some authors of signal cables is measured with the total current flowing on the cable as a function of frequency This quantity can be easily obtained from an AC simulation at one of the cable termination With ICAP 4 version 7 x one could for instance issue an ICL block such as control save allcur alias imc mag i v1 i v2 i v3 i1 v4 i v5 i v6 1 v7 i v8 endc PRINT AC IMC 3 8 Theory of emission by conduction and by radiation problems SpiceLine is able to compute the emission by conduction also called conducted emission by some Document 00012107B page 15 authors at a given abscissa along the cable and the emission by radiation also called radiated emission by some authors of a cable at a given point in space in the frequency domain This feature is only available if a change of variable is selected such that the last element of the transformed current vector is the common mode current and such that the last element of the transformed voltage vector is a common mode voltage The changes of variable given by formulas 21 to 24 meet t
22. ct change of variables and select utpla cov for the A matrix and utp1b cov the B matrix because you are going to introduce transformed inductance capacitance and resistance matrices Ly Cr and Ry as input matrices see 3 5 m Use Line parameters Edit input matrix to enter the L matrix the C matrix and the R matrix Do not press Esc while editing a matrix because it will be lost You first select Line parameters Edit input matrix L in order to use the Input Matrix Editor LT to enter the L matrix taking care that you must press the enter key after typing each number so that the entered number becomes justified on the right Document 00012107B page 27 of each cell Enter the following Lr matrix in H m 0 693 0 002 0 002 0 543 0 47 0 0 0 996 You must use the decimal separator specified in your Windows system When your matrix is entered press save in the Input Matrix Editor LT don t take the warning message into account then press Create output then Verify output Important do not click on Save after after pressing Create output this would save the values of the output matrix as the input matrix Proceed in the same manner to enter the following Cr matrix in pF m 48 008 0 0 08 766 O0 48 0 0 20 2 Proceed in the same manner to enter the following Ry matrix in Q m 0112 0 0 0 0 061 0 033 49 0 0 033 0035 m Use Line parameters View output matrix to look at your output L C and R matrices In t
23. currents are given for 3 different orthogonal orientations so that the polarisation of sources is taken into account In fact the computation method used for immunity is based on reciprocity and a computation of emission For this reason the characteristics of emission and immunity calculation done by SpiceLine are the same For instance immunity predictions are offered for AC SPICE simulations only As is the case for the computation of emission by radiation the computation takes into account type 1 coupling and type 2 coupling Also the induced voltages and currents computed by SpiceLine are valid in the near field of the source Document 00012107B page 6 3 Theory of operation 3 1 The inductance capacitance and resistance matrices SpiceLine is meant for the simulation of multiconductor cables having n conductors A reference conductor being always implied the problem is in fact a n 1 conductor transmission line The key input parameters of the SpiceLine software are the inductance matrix L and the capacitance matrix C eventually the resistance matrix R of a transmission line with respect to a reference conductor for instance a ground plane They are square n x n matrices containing per unit length quantities respectively in H m F m and Q m All voltages are considered with the reference conductor as ground reference The properties and limitations of such a transmission line model are widely presented in the literature and wil
24. e conditions g n rales de vente are printed on the back of the invoice They include the definition and the limitation of warranty This software is supplied As Is However Excem will make its best efforts to solve any problem related to a malfunction of the software The Licence is subject to Excem s General Terms of Sale The Licensee may use the SpiceLine software on a number of computers equal to the number of copies purchased Please note that the software licences are NOT transferable 1 4 Updates and printing history Each technical document emanating from Excem carries a single and individual document number This number is printed on the left of the bottom line of each page Please keep track of additional relevant documents pertaining to your SpiceLine software package The User s guide dated November 1996 document 95104301B is cancelled The User s guide dated July 1998 document 98042103B is cancelled The User s guide Update dated July 1999 document 99072101A is cancelled The Reference Manual dated March 2000 document 00012108B is applicable to SpiceLine 2 23 Document 00012107B page 4 2 What is SpiceLine 2 1 A software for emission immunity and crosstalk predictions SpiceLine is intended for computing emission immunity and crosstalk of multiconductor transmission lines Each problem starts with the description of the multiconductor transmission line with two
25. e assume that ICAP 4 is installed in the Spice or Spice4 directory of the current drive Please follow the six steps below applicable to ICAP 4 Windows Please note that some deviation from this procedure might be needed according to your version please check your manual Step 1 copy the contents of the for_pr directory of disk 4 into the PR directory Spice PR or Spice4 PR Step 2 copy the contents of the for_sn directory of disk 4 that is to say the symsplne subdirectory and its files into the SN SYMBOLS directory Spice SN S YMBOLS or Spice4 SN S YMBOLS Step 3 copy the contents of the for_cir directory of disk 4 into the CIRCUITS directory or into an other subdirectory of Spice or Spice4 Step 4 If you are using ICAP 4 Windows version 7 6 using a text editor add sn symbols symspIne at the end of the Spice4 sn sym file Step 5 compile an updated SpiceNet database If you are using ICAP 4 Windows version 7 6 this is simply accomplished by running MakeDb exe in SN Spice SN or Spice4 SN double click MakedB exe in your Windows Explorer then click on Run Sindex then click on Run DBMake Step 6 test that you can access your new cable models under the SpiceLine2 23 heading in the SpiceNet Parts Browser dialog For earlier versions of ICAP step 5 may require 3 substeps for instance Substep 5 1 update the Lib file that contains the list of libraries This is simply ac
26. ed current 0 2 56 cho ew onde 6 17 induced voltage onic 2e ies 6 17 inductance matrix sits OS hs See eas 7 input matrices ose be he ee he es 7 14 T stallati t yas Les Ram ne 24 inverse transformed input matrices 14 L MOd lE na Media at nca Ru hr ey 8 License Poi oko haa aides oe ae e 4 LOSSES rs er arts dattes tek 14 lossless model 14 M model 2 x4 feet twats suet ore he okt tes 9 modal characteristic impedance 9 modal transform 10 modified input matrices 14 nominal height 13 26 27 Normalization 20 output matrices Les aie peewee bene 7 14 parameter 53 4 SEMI TA 10 reference height 4 fe Vesa Bees 13 26 27 resistance matrix R 7 R CA te tre E de den te ela 11 LE TALK es in ue ee nee SA 9 transformation 11 transformed currents 11 transformed voltages 11 DH RP RE PT ET 11 warranty Le pen nent alae chere eve 4 7 Appendix Results obtained with Example 2 The next pages present the results one could obtain if one follows the steps of 4 6 Page Al shows the stp1p circuit The length of the cable is 10 m The characteristic impedance for the differential mode is close to 120 Q and the source amplitude is 1 V Page A2 shows the stplpl cir file Page A3 shows the common mode voltage in the middle of the cable in dB above 0 5 V Pa
27. edances The first problem can be described as the consequence of neglecting the off diagonal terms of the R matrix This can be cured by adding a current controlled voltage source an H element according to the SPICE syntax in series with each relevant conductor in the MTL SPICE model It can be done at one or both ends of the conductor in such a way that the total transimpedance or transresistance in this case i e the ratio of output voltage of the H element to its input current is equal to the off diagonal term of R 0 Hz Let us call this cosmetic measure 1 Document 00012107B page 14 The second problem mentionned above occurs when conductors other than the reference conductor are grounded or connected to ground with a low impedance termination For example a common practice is to have many grounded at both ends conductors on flat unshielded ribbon cables for improved EMC characteristics In the case of an MTL including one or several shields the shields are also normally grounded at both ends Each conductor with low impedance to ground at both ends provide some shielding Neglecting losses over estimates their shielding effectiveness at low frequencies This is because in the lossless model their per unit lenght impedance decreases to zero at zero frequency instead of being limited by their per unit length DC resistance This per unit length resistance is equal to the corresponding diagonal term of R O Hz minus the per unit length
28. eometrical mean distance for which the Ly and Cy matrices have been entered hy is the nominal height that is to say the height geometrical mean distance for which the SPICE models will be computed h is a height taking on the value h or hy as appropriate we assume that only the last row and last column of the L matrix is modified by the change of height in such a manner that for any integer i between 1 and n Ho h A In h Taal 27 ne FL r u h Fe A In h EX 27 Bp Li R and that only the last row and last column of the Cy matrix is modified by the change of height in such a manner that for any integer i between and n Document 00012107B page 13 1 h C h ln C h T gh 2TE h T a r 1 h 1 C h In C h T ul 2TE h T sl A Of course this model gives only an estimate of what the L and C could be for this new height and let us recall that it is limited to STP cables 3 5 Sequence of operations on input data The user enters the Ly Cy and Ry matrices referred to as input matrices in SpiceLine SpiceLine then implements the modification for the new cable height according to 3 4 it computes the modified input matrices If no change of cable height is specified the modified input matrices are of course equal to the input matrices SpiceLine then implements the inverse transform defined by the A and B matrices according to 3 3 in order to recover t
29. ge A4 shows the common mode current in dB above 4 167 mA at the same point Page AS shows the radiated electric field at the point of coordinate 0 1 m 1 m 0 m in dB above 1 uV m Page A6 shows the magnetic field at the same point in dB above 1 uA m Page A7 shows the current in dB above 1 mA induced by a field normalized to 1 V m at the origin produced by an electric dipole at the point of coordinate 0 1 m 1 m 0 m for the x polarization Page A8 shows the current in dB above mA induced by a field normalized to 1 A m at the origin produced by a magnetic dipole at the same point for the y polarization Document 00012107B page 31 Ai F Z SN LE KXXX 7 aes f OOK ain C OV e FOYNOSA YX de veo 3 d8 d8 Szo 929 94 9c4 DIRES Sed dv 0 9 d9 d9t LEO ZED Ob O 4 Ok 6c4 Page A1 5a SPICE4 cnetasin spicfich stpipl cir E SPICE4 CIRCUITS utp4apl SPICE_NET AC DEC 20 1000HZ 100MEGHZ PRINT AC V 1 VP 1 PRINT AC I V1 P V1 PRINT AC V 2 VP 2 PRINT AC I V2 P V2 PRINT AC V 3 VP 3 PRINT AC I V3 P V3 INCLUDE SPLNE223 LIB V2 37 2 R1 9 39 120 VSOURCE 9 37 AC R5 17 12 120 C24 12 17 2P R25 0 12 1G R26 0 17 1G C25 0 17 8P C26 0 12 8P C30 37 39 4P R29 0 37 1G R30 0 39 1G C31 0 39 16P C32 0 37 16P V3 0 3 X4 1 2 3 17 12 0 0 ST12E L 10
30. he L C and R matrices These matrices are called the inverse transformed input matrices referenced to ground If no change of variable is specified the modified input matrices are of course equal to the modified input matrices Some manual editing can then be done on the inverse transformed input matrices using a Diagonal multiplying factor and a Non diagonal multiplying factor This leads to the generation of the output matrices This manual editing is sometimes necessary in order to pass the criteria defined in 3 1 when the matrix values were obtained from inaccurate measurements The next operation consists in computing the eigenmodes of the cable assumed lossless One can then create SPICE models which will eventually take losses into account to some extend see 3 6 3 6 Taking losses into account The explanations given in this paragraph are derived from 2 A lossless model of a cable is generally expected to over estimate the induced voltages and currents This is usually acceptable to the user because it leads to an additionnal margin in the design process There is nevertheless two special cases where a lossless model usually gives rise to an over optimistic assessment of unwanted signal The first case is related to the real part of the reference conductor impedance the second case occurs if conductors of the multiconductor transmission line MTL are terminated at both ends to the reference conductor with low imp
31. he near end of the cable on the ground plane More precisely at a given abscissa z along the cable the value of the chain supermatrix is Scosh yz S Z T a 27 T sinh y JT Z Tcosh yz T Y 0 Y Therefore the voltage and currents at z can be computed from the voltage and current computed by the SPICE software at the near end z 0 as v z _ Scosh y z S Z T sinh y z T v 0 se i z Tsinh yz T Z Tcosh y z T i 0 28 where v z and i z are the voltage vector and current vector at abscissa z along the cable where v 0 and i 0 are the voltage vector and the current vector at the near end This formula does not take any cosmetic measure into account and therefore only applies to the lossless case In fact SpiceLine computes the voltage and currents at z as Document 00012107B page 16 4 RER of S cosh y z S ZT sinh y z T Wicd T2 Rist 29 i z Tsinh yz T Z Tcosh yz T where Vspie ANd ispice are the voltage vector and the current vector computed by SPICE and where L is the total cable length SpiceLine will deliver the v z and i z vectors at an abscissa z specified by the user The computation of the radiated fields is based on the assumption that the reference conductor is an ideal i e infinite and perfectly conducting ground plane The fields radiated by the cable above the ideal ground plane if one considers only type 1 and type 2 emission mechanisms are determined
32. he present case they are equal to the input matrices m Use Line model Compute eigenmodes to compute the mode propagation velocities the eigenvectors the characteristic impedance matrix m Use Line model View modes if you wish in order to inspect the computed quantities m Use Line model Compute Spice models for storing the SPICE model Again type mycables lib as file name Select and D and E models with names like ps d and ps e in the four Name boxes Select All terms in order to take the resistance matrix into account Select Add You just added two models to the mycable lib library file file of Sline files This library mycable lib should now be copied in the PR directory Spice PR or Spice4 PR in order to be used by the ICAP 4 SPICE simulator Note that for the SPICE model just created the stplp sym model included in Spice SN S YMBOLS S YMSPLNE is appropriate Following the appropriate steps you can also edit the new library by adding appropriate SRC and S YM lines to each model see the supplied spIne223 lib library then compile a new data base and thus become able to access your models created with SpiceLine in the SpiceNet Part X part Browser window m You should now perform a SPICE simulation of a name cir SPICE project including for instance the psid subcircuit according to the requirements of 3 8 You may for instance copy the 6 files stp1p found initially in the for_cir directory of disk 4 see step
33. his requirement The steps for the emission computation are the following 1 create a model of the cable 2 prepare the AC simulation making sure that at the near end of the cable conductor 1 of the cable is at node N1 conductor 2 at node N2 and that a source V1 meant for current measurement has its negative node connected to node N1 a source V2 has is negative node connected to node N2 3 simulate the model making sure that the only PRINT statements are in the following order PRINT AC V 1 VP 1 PRINT AC I V1 IP V1 PRINT AC V 2 VP 2 PRINT AC I V2 IP V2 etc 4 Select the output file of this simulation OUT file in SpiceLine so that the voltage and current values at the near end of the cable computed by SPICE is known from SpiceLine Note that the for_cir directory of disk 3 contains the utplpl stplpl utp4p4 and stp4p4 SPICE projects that meet the requirements of point 2 above For each frequency in this output file SpiceLine will establish the chain supermatrix This supermatrix allow the straightforward computation of all voltages and currents along the cable Then according to 3 the type 1 and type 2 emission mecanisms are used to compute the emission of the cable at a point P specified by its right hand cartesian coordinate X Y Z X being a vertical distance above the horizontal ground plane Z being an horizontal distance parallel to the cable the origin being the orthogonal projection of t
34. is the name of the project the L input matrix is in filename INL the C input matrix is in filename INC the R input matrix is in filename INR the L output matrix is in filename OUL the C output matrix is in filename OUC the R output matrix is in filename OUR filename ERL is a text file describing errors found during the verification of the L output matrix filename ERC is a text file describing errors found during the verification of the C output matrix filename ERR 1s a text file describing errors found during the verification of the R output matrix filename CVA contains the A matrix used in the project filename CVB contains the B matrix used in the project 4 4 Sequence of operations with SpiceLine A full SpiceLine session for obtaining SPICE models contains the following three steps 1 creating a new project or opening an existing project 2 defining the line parameters 3 creating one or several ICAP4 Windows compatible line models These models are stored in a libname lib file and can later be used in any circuit that you want to simulate If you also want to compute a radiated emission you need to accomplish three additional steps 4 running a ICAP4 Windows version 7 x simulation meeting the requirements of 3 8 Document 00012107B page 25 5 computing the radiated fields with SpiceLine using the name out file generated by ICAP4 Windows 6 displaying the results stored in the name2 out file generated by
35. l not be discussed here Let us only note that the conductance matrix G of the transmission line is assumed negligible and that the L C and R matrices are assumed frequency independant These matrices may be directly entered by the user Alternatively the user will enter other matrices see 3 3 3 4 and 3 5 and SpiceLine will compute the L C and R matrices In any case the matrices entered by the user are called input matrices and the L C and R matrices finally used to create the transmission line model will be the output matrices The output matrices must obey a certain number of basic properties They can be verified by SpiceLine For the L matrix these properties are the L matrix is square of size n the L matrix is symetric Vi 1 lt i lt n h p 1 we have Dy Vj 1 lt j lt n Ar a all coefficients of L are positive Vi 1 lt i lt n we have L 2 0 2 Vj 1 lt j lt n Lis the matrix of a positive definite forme therefore Vi 1 lt i lt n 3 l wehave LL gt G 3 Vj 1 lt j lt n tt and if we denote L the submatrix of L containing only the lines 1 to i and the columns 1 to i we have for the jacobi determinants Vi 1 lt i n L gt 0 4 For the C matrix these properties are the C matrix is square of size n the C matrix is symetric Document 00012107B page 7 le 1 lt i lt n T D ee x the diagonal coefficients of C are positive while the non diagonal coefficents are
36. les in this directory The directory for_sn of disk 4 contains in the for_sn symsplne subdirectory some SpiceNet symbols demec sym this is a braid sub symbol used as a cable screen in our STP symbols masl sym this is a reference conductor sub symbol used in other cable symbols pair sym this is a twisted pair symbol also used as sub symbol in our STP and UTP symbols fredline sym a symbol for a cable with two shielded pairs and two conductors in the middle stplp sym a symbol for a single twisted pair cable screened stp4p sym a symbol for a cable with 4 twisted pairs screened utplp sym a symbol for a single twisted pair cable not screened utp4p sym a symbol for a cable with 4 twisted pairs not screened The directory for_pr of disk 4 contains two files Document 00012107B page 22 spIne223 lib is a library file containing various Spice subcircuits created with SpiceLine mycables lib is an empty library file for storing your own Spice subcircuits The splne223 lib library file contains 6 SPICE models FREIE is the original model used in 2 created with an earlier version of SpiceLine This is a lossless E model for a flat cable with one shielded pair two conductors and an other shielded pair FLA1D is a model created with SpiceLine using the same data as the one used for FREIE contained in the IEEE0296 SpiceLine project This is a D model for which all terms of the resistance matrix have been taken into accou
37. ll magnetic dipole made of a circular loop of surface S at the point P we know that the short circuit current induced in this dipole by the fields produced by the voltage Vy is JOU S In gt Br 40 H where Zy is the dipole impedance and where u is a unit vector orthogonal to the plane of the loop Let us now assume that we replace the voltage source which produced the current Vy with a short Document 00012107B page 19 circuit in which we measure the current Z using generator s sign convention associated with the sign convention choosen for measuring V If we install a voltage source delivering a voltage Vp to the electric dipole measured with the generator s sign convention associated with the sign convention choosen for measuring the reciprocity theorem tells us that we will measure Ip Vp jou u H 0 PM 41 Va Va Pie T2 where M M u is the magnetic dipole moment measured positive in the direction of u If one creates a SPICE simulation for computing the electric field H p radiated for Vy 1 V SpiceLine will compute in this manner the current Zp induced by a magnetic dipole with an amplitude of 1 Am Normalization of the response to external fields When studying the immunity of a circuit to external radiated disturbances it is customary to relate the effect in our case the induced current Z or the induced voltage Vy to the value of the incident field at a given point We have choosen to
38. matrix because you are going to directly introduce the L matrix the C matrix and the R matrix for this cable as they are defined in 3 1 m Use Line parameters Edit input matrix to enter the L matrix the C matrix and the R matrix Do not press Esc while editing a matrix because it will be lost You first select Line parameters Edit input matrix L in order to use the Input Matrix Editor LT to enter the L matrix taking care that you must press the enter key after typing each number so that the entered number becomes justified on the right of each cell Enter the following L matrix in uH m 0 816 0 27 j 0 27 0 816 Ge You must use the decimal separator specified in your Windows system When your matrix is entered press save in the Input Matrix Editor LT don t take the warning message into account then press Create output then Verify output Important do not click on Save after after pressing Create output this would save the values of the output matrix as the input matrix Proceed in the same manner to enter the following C matrix in pF m 489 12 1 A 12 1 489 2 In this example we are not interested in taking losses into account and we therefore do not enter any R matrix m Use Line parameters View output matrix to check your output L matrix and output C matrix In the present case they are equal to the input matrices m Use Line model Compute eigenmodes to compute the mode propagation velocities the eigenvectors
39. negative Vi 1 lt i lt n PEPE i we have C 20 and i j C lt 0 6 Vj 1 lt j lt n m C is the matrix of a positive definite forme therefore Vi 1 lt i lt n gt i we have C C gt C 7 Vj 1 lt j lt n NON and if we denote C the submatrix of C containing only the lines 1 to i and the columns 1 to i we have for the jacobi determinant Vi 1 lt i lt n KC gt 0 8 The sum of the coefficients of any line respectively any column of C is positive Vi 1 lt isn YC 20 g 9 Vj 1 lt j lt n Y C 20 B I For the R matrix these properties are the R matrix is square of size n the R matrix is symetric Vi 1 lt i lt n h R we have kK k 10 Vj 1 lt j lt n Ay Ry om a all coefficients of R are positive Vi 1 lt i lt n h s we have R 2 gt 11 Vj 1 lt j lt n R i for the DC resistance matrix all non diagonal coefficient are equal and smaller than any diagonal coefficient 3 2 Theory of transmission line modeling with SPICE The lossless L model created by SpiceLine see 2 2 only implements lumped inductors coupling between inductors and lumped capacitors A lossy L model also includes the required lumped resistors at both ends see 3 6 assuming that the dielectric losses are negligible i e the per unit length conductance matrix is not accounted for This equivalent circuit is directly derived from the output Document 00012107B page 8 matrices The limitation of the lossless L model and loss
40. normalize the effect of a dipole having any orientation lying at the point P of coordinates X Y Z in the following way If it is an electric dipole it will take on the electric dipole moment value which would produce an electric field E 1 V m at the cable near end in an empty space if the electric dipole was oriented in such a direction that the cable near end would lie in the plane of maximum far field radiation of the dipole If it is a magnetic dipole it will take on the magnetic dipole moment value which would produce a magnetic field H 1 A m at the cable near end in an empty space if the magnetic dipole was oriented in such a direction that the cable near end would lie in the plane of maximum far field radiation of the dipole Thus the electric dipole moment takes on the value AT Ey h E 42 or the magnetic dipole moment takes on the value AT Mo H 43 1 k k 3 5 r r r the value of r in 42 and 43 being r X a r 2 44 for a cable near end at the coordinates hy 0 0 Document 00012107B page 20 4 Getting started 4 1 Initial inspection and parts list 4 1 1 Unpacking You should have received the present User s Guide the Reference Manual and five floppy disks 4 1 2 Disk 1 The floppy disk contains the files spline23 exe mat vts mat bak matout vts vect vts 4 1 3 Disk 2 The floppy disk2 contains the files bc4SOrtl dil bds52 dil
41. nt No change of variables was implemented UT12E is a model for a single pair UTP cable created with SpiceLine using the data contained in the UTPD1 SpiceLine project We implemented the utpla cov and utplb cov changes of variable respectively for A and B This is a E model for which all terms of the resistance matrix have been taken into account UT42E is a model for a 4 pairs UTP cable created with SpiceLine using the data contained in the UTPD8 SpiceLine project We implemented the utp4a cov and utp4b cov changes of variable respectively for A and B This is a E model for which all terms of the resistance matrix have been taken into account ST11E is a model for a single pair STP cable created with SpiceLine using the data contained in the STPD1 SpiceLine project We implemented the stpla cov and stplb cov changes of variable respectively for A and B This is a E model for which only the diagonal terms of the resistance matrix have been taken into account ST12E is a model for a single pair STP cable created with SpiceLine using the data contained in the STPD1 SpiceLine project We implemented the stpla cov and stplb cov changes of variable respectively for A and B This is a E model for which all terms of the resistance matrix have been taken into account ST42E is a model for a 4 pairs STP cable created with SpiceLine using the data contained in the STPD8 SpiceLine project We implemented the stp4a cov and stp4b cov changes
42. of variable respectively for A and B This is a E model for which all terms of the resistance matrix have been taken into account The directory for_cir of disk 4 contains ICAP 4 files for 6 projects ieeeter ieeequar utpIp1 stplpl stp4p4 utp4p4 The file names of the file belonging to these projects are made with the name of the project and the following extensions cl cir ckt cnt con d1 Each circuit name cir has therefore 6 files in the subdirectory Document 00012107B page 23 name cir name cl netlists created by SpiceNet name cnt name con control statement for SpiceNet name ckt SPICE compatible netlist name d1 schematics 4 1 6 Disk 5 Disk 5 contains two Acrobat Reader compatible files maspli2e pdf for the User s guide maspli2f pdf for the Reference manual These files are intended to be used with Acrobat reader 3 0 or later versions Acrobat Reader 4 0 or later version is recommended because of its superior printing capabilities 4 2 Installation SpiceLine is designed to work under Microsoft Windows 95 98 Please create on your hard disk a Sline directory and if you wish a subdirectories like Sline files Copy the contents of Disk 1 Disk 2 and Disk 3 in Sline Copy the contents of the root of Disk 4 and if you wish the contents of the examples directory of Disk 4 into Sline files Please also copy the mycable lib file of the for_pr directory of disk 4 into Sline files W
43. ons 2 3 Capabilities of SpiceLine emission predictions Assuming the transmission line is a cable or bundle installed above an ideal ground plane if a suitable change of variables was implemented it is possible to compute the radiated emission of the line at a given point in space This capability is offered for AC SPICE simulations only non linear behaviours of terminations are therefore not taken into account The computation takes into account type 1 coupling i e common mode current on the cable and type 2 coupling i e common mode voltage Higher order coupling phenomena are not taken into account The radiated fields computed by SpiceLine are valid in the near field Cable with one or several screens are taken into account as far as the screen is well described by the frequency independant inductance and resistance matrices Of course the effect of various screen grounding techniques can be easily assessed The decrease in radiated emission resulting from the twisting of pairs is also taken into account in the kind of model implemented 2 4 Capabilities of SpiceLine immunity predictions Assuming the transmission line is a cable or bundle installed above an ideal ground plane it is also possible to compute the voltage and current induced on the transmission line by external field sources at a given point in space The source can be an infinitesimal electric dipole or an infinitesimal magnetic dipole The induced voltage and
44. or three matrices of suitable per unit length parameters SpiceLine then generates a SPICE model of the transmission line This SPICE model can be used directly in a SPICE simulator for frequency domain simulation AC simulation in the SPICE wording or time domain simulation TRAN of crosstalk From the results of an appropriate frequency domain simulation the OUT file SpiceLine is also able to compute the frequency domain emission by radiation of the transmission line considering type 1 coupling and type 2 coupling Immunity of a system to radiated disturbances can also be assessed from a frequency domain simulation 2 2 Description of the transmission line and crosstalk predictions SpiceLine 2 23 with Telecom Line Predictor is able to compute SPICE compatible models for lossless multiconductor transmission lines from line inductance and capacitance matrices provided by the user SpiceLine is also able to include some losses in those lossless model according to an empirical model If one wishes to include losses a resistance matrix must be provided SpiceLine is able to generate 4 different lossless SPICE models for any given transmission lines L Model implements lumped inductors coupling between inductors and capacitors M Model implements lumped inductors and capacitors and B elements D Model implements lossless transmission lines and B elements E Model implements lossy transmission lines and B elements
45. point P If we now install a small electric dipole made of two aligned segments of length d at the point P the short circuit current of this dipole excited by the fields produced by the voltage Vy is Ip yk E 38 where Zz is the dipole s impedance and where u is a unit vector aligned with the dipole Let us now assume that we replace the voltage source which produced the current Vy with a short circuit in which we measure the current using generator s sign convention associated with the sign convention choosen for measuring V If we install a voltage source delivering a voltage Vp to the electric dipole measured with the generator s sign convention associated with the sign convention choosen for measuring the reciprocity theorem tells us that we will measure E Ip Vp j u P P 39 Ir Vn Va where P P w is the electric dipole moment measured positive in the direction of u If one creates a SPICE simulation for computing the electric field E p radiated for Vy 1 V SpiceLine will compute in this manner the current induced by an electric dipole with an amplitude of 1 Cm case d current induced by a magnetic dipole As previously let us consider the emission by radiation of a cable excited at the near end termination by a unique voltage source delivering the voltage V We are able to compute the electric field E p and the magnetic field H p at a given point P If we now install a sma
46. s work covered by the copyright hereon may be reproduced or translated to another language or used in any form or by any means graphic electronic or mechanical including photocopying recording taping or information storage and retrieval systems without the written permission of the publisher Unlike other document concerning SpiceLine any person is entitled to download one copy of the Adobe Acrobat maspli2e pdf file containing the electronic form of this work on a single computer from the http www excem fr site or from the http www eurexcem com site Printing this file several time on paper by the said person is permitted provided the resulting printed documents are only used for the private usage of the said person Excem 12 chemin des Hauts de Clairefontaine 78580 Maule France tel 33 134 75 13 65 fax 33 1 34 75 13 66 e mail info excem fr site excem fr Document 00012107B page 3 Please note that Tntusoft and ICAP 4 are trademarks of Intusoft m Adobe and Acrobat are trademarks of Adobe Systems Incorporated m Microsoft and Windows are trademarks of Microsoft Corporation m SpiceLine is a trademark of Excem soci t anonyme 1 3 Terms of sale warranty license for the SpiceLine software Unless otherwise specified in your contract with Excem our General Terms of Sale applicable at the date of the invoice shall apply to the SpiceLine Software These terms of sal
47. t 00012107B page 9 the voltages of the conductors 1 to n of the cable measured at the same distance z from the near end between each conductor and the reference conductor and v the corresponding column vector The modal transform is defined as 17 where v is the vector of the n modal voltages and i the vector of the n modal currents In the modal domain each voltage and current of index propagates at the velocity c with the modal characteristic impedance Zom This short theoretical sketch contains all that is needed for the computation of propagation and crosstalk ofa multiconductor transmission line Using 17 the problem of n 1 coupled conductors is changed into a problem with n uncoupled 2 conductors transmission lines with a known propagation velocity and a known characteristic impedance The lossless SPICE model created by SpiceLine is based on this computation Let us finally note that some authors do not use 13 but another condition Our practice of defining a matrix S in this manner gives the relationship 1 Zooma 7 18 for the mode characteristic impedance for mode i In SpiceLine we adopt k 10 This keeps the modal impedance within the physical bounds of a characteristic impedance say between 10 Q and 1000 Q values for which SPICE may be expected to work properly Practically eigenmode transformation is implemented with B elements It is difficult to introduce losses in such models and we ha
48. ve therefore introduced an heuristic approach 2 to include some losses in SPICE models for multiconductor transmission lines with lumped elements at both ends of a lossless multiconductor transmission line models This approach is explained at 3 6 Of course such lossy models are inappropriate if the line is too long because in this case those lumped elements bring a mismatch in the model that is not present in the real world The M model implements an eigenmode transformation but it is based on lumped elements for the propagation of the eigenmodes The purpose of the eigenmode transform is to remove all coupling between inductors which have sometimes been reported to create convergence problems in some SPICE like simulation software For the D model the propagation of the uncoupled eigenmode is described with distributed lossless transmission line models the T elements of SPICE whereas for the E model the propagation of the eigenmode is modeled with distributed lossy transmission line model the O elements of SPICE without losses per unit length resistance and per unit length conductance of the lossy transmission line model set to 0 L models M models and D models have only one parameter L for the length of the line in meter which defaults to L 1 meter E models have two parameters the line length L in meter which defaults to L 1 meter and the R parameter which is the dimensionless REL breakpoint control parameter of the
49. y L model do not deserve much discussion The M model D model and E model created by SpiceLine are based on the eigenmodes of a lossless transmission lines The theory for creating eigenmode based Spice models for lossless multiconductor transmission lines is well known and presented in 1 and 2 Let us summarize it Because of the properties of L and C the product matrix CL can be diagonalised with a real T matrix T CLT 2 12 gt S s 1 0 0 7e 2 where the quantity c Ca can be shown to be the propagation velocities of each of the n modes We define the S matrix as S kC T 13 where k is an arbitrary positive constant S diagonalizes the LC matrix Y 0 0 C1 E a i S LCS 2 14 ee 0 0 Ye 2 Cn An important quantity is the characteristic impedance matrix Z defined as 1 eae qe 0 0 Oe es tek Fe lg Z C T T 15 te 0 sae 1 AOC It has the property of being the impedance of a n pole which when connected to an end of the multiconductor transmission line would absorb any incoming signal without reflection One should also introduce the modal characteristic impedance matrix defined as Z S Z T It is diagonal Z mi 0 6 0 OF ETS Zon S ZT Su ee 16 0 0 Zoni Let us note i i the currents flowing into the conductors 1 to n of the cable measured at a given distance z from the near end of the cable and i the corresponding column vector Let us note V Documen

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