024601-4-T MENU DRIVEN FULLWAVE ANALYSIS OF MICROSTRIP DISCONTINUITIES USER MANUAL W.P. Harokopus, Jr. December 1991

- e, r, I I d I j it I

Menu Driven Fulliwave Analysis of Iliicrostrip Discontinuities User Manual WV. P. Haroklopus, Jr. 1 Preface This user manual provides the necessary )ackground to run successfully the FORTRAN codes written by \NVilliam lIarokopus for the study of high frequency microstrip elements. The codes are menu driven and provide answers in the form of scattering parameters for 1, 2, 3, and 4-port elements. The codes were developed during the period from Janii. S7 an1d September 91.

2 Introduction The Numerical codes discussed in this report were developed from the Space Domain Integral Equation Technique. This technique has been used extensively for the study of microstrip structutres and is believed to be very accurate. This is particularly true in the study of veiy highl frequency components. Informcation on the technique and its application to microstrip may be obtained in the publications by Harokopus and Katehi. The menu driven programs arc designed to operate in two phases. The first phase evaluates coupling interactions resulting from the method of moments treatment. This phlase requires kTnowleclge of the substrate parameters, the discretization size, the mesh size, and the frequency. Phase two solves for 1,2,3 or 4-port scattering parameters and therefore requires more precise information concerning the dimensions of the particular dliscontinuity being studied. The programing was divided into these two stages for two reasons which are: * The first is that phase one can b)e far more time-consuming than phase 2. * The results from phase one a.re re-usable for different structures or dimensions The following sections demonstrate correct menu operation, show how to compute discretization and mesh parameters, and provide several examples including final results. A basic knowledge of microwave terminology and convention is assumed.. A listing of program names and locations on the CAEN network is given in appendix A.

3 Interactive Menu 3.1 Phase I After running phase 1 (entitled s2main.ftn), the user is prompted for various parameters concerning the substrate, and mesh size. A listing of the variables involved includes F(operating frequency),TD(metallization thickness), T2(substrate height), dlx, and dly (length and heighlt of discretization), nxn and nym (integer size of meshl), and FI(outtputt file for ilnpedance Inatrix vector). The units for many parameters mi-ay be entered in rmm, mils, or free space Nwavelengths. After entry of all parameters a table is printed a.s shown below: ae of geometry configuration file [NAME] ma50.fmt )strate rel. dielectric constant; [ER]: 10.0000 4ENSIONS NORMALIZED TO FREE SPACE WAVELENGTH 4ENSION ENTRY IN MILS: CHANGE UNITS [CU] normalized (mils) (millimeters) Bquency (GHz) of operation (lambda_o) [F] 50.0000000 ( 236.0570831) ( 5.9958496 ickness of metallization [TD].0211813 ( 5.0000000).1270000) ickness of metallization [T2].0000424 (.0100000) (.0002540 ngitudinal subsection length [DLX].0105907 ( 2.5000000) (.0635000 ansverse subsection length [DLY].0105907 ( 2.5000000) (.0635000 rmalized longitudinal mesh length; [nxn]: 60 rmalized transverse mesh width; [nym]: 60 ta file for admittance matrix [FI] meand50.out nter Variable Name [**] or <return> Incorrect entries may be correcte(l ly ientering the (Insired variable shown in parantheses and typing the new value when prompted.

3.1.1 Determilling Discretization Size This version of the program allows for only a square discretization size(dlx=dly). The discretization should be made withl two considerations in mind. The first is to have a grid size which is has no fewer thlan 25 and no more than 80 subsections per guide wavelength. Using less thlan 25 wvill compromise accuracy, and using more than 80 will make the number of unlcnowns too large. In general 30-40 is the optimal range. The second consideration is'clloosing a grid size vwhich conforms to the dimensions of the discontinuity(s) to be simutilated. Dimensions of the structure must be multiples of the grid size. 3.1.2 Determining Mesh Size The parameters [nxn] and [nym] are the integer length of the meshl in the x and y directions. The total size of the mesh is obtained by multiplying these parameters by the discretization size. The meshl must be at least as large as the discontinuity and its corresponding feeds. For square discretizations the mesh must be square(nxn=nym). 3.2 Phase II Phase II enters the intermediate results(impedance vector) from phase I, fills a matrix according to dimensions and structure type designated by the user, solves the matrix, and provides restults in [s]-parameter form. After execution of the program [Inlpdisc.ftn], the program prompts the user for the configuration file nalne:

Enter name of configuration data file; The user enters the configuration file generated from phase 1. The program then asks for the number of ports: Select number of ports: [1] 1-port [2] 2-port [3] 3-port [4] 4-port After selection of the nutmber of ports the program enters sub-menus to determine the discontinuity to be analyzed. For example a mitered bend simulation would appear: [1] right angle [2] mitered [3] optimally mitered The program then requires the dimensions of the bend. All simulations also require the effective dielectric constant vwhichl must be determined in advance from touchstone or other 2-D simulations. After entry of this data a menu is printed to the screen: ame of geometry configuration file [NAME] ma70 over rel. dielectric constant; [ER]: 10.0000 IMENSIONS NORMALIZED TO FREE SPACE WAVELENGTH IMENSION ENTRY IN MILS: CHANGE UNITS [CU] normalized (mils) (millimeters) requency (GHz) of operation (lambda_o) (F] 70.0000000 ( 168.6121979) 4.282749 hickness of cover [TD] 0.0296538 ( 5.0000000) ( 0.1270000 hickness of metallization [T2] 0.0000059 ( 0.0010000) ( 0.0000254 ongitudinal subsection length [DLX] 0.0148269 ( 2.5000000) ( 0.063500C ransverse subsection length [DLY] 0.0148269 ( 2.5000000) ( 0.063500C idth of line [WW] 0.0148269 ( 2.5000000) ( 0.0635%OC ength of feed line [XLL] 0.4448077 ( 75.0000000) ( 1.9050G0C ffective dielectric constant [XK] 6.6999998 ormalized longitudinal mesh length; [nxn] 60 ormalized transverse mesh width; [nym] 60 ata file for admittance matrix [FI] meand70 Enter Variable Name [**] or <return>

The user nmay ie-enter incorrect parameters a.t this point. He may Inot change parameters which were set in phase 1. After returning the program will run and in several seconds to several mintutes the answer will be printed to the screen. In the case of a T-junction for example: PERFORMING BACKSUBSTITUTION (even) PERFORMING BACKSUBSTITUTION (odd) PERFORMING BACKSUBSTITUTION(3) S( 1 1) 0.3017638 166.4064 S( 1 2) 0.6937661 -11.21025 S( 1 3) 0.6458406 2.621903 S( 2 1) 0.6937646 -11.21055 S(, 2 2) 0.3017560 166.4059 S( 2 3) 0.6458471 2.621877 S( 3 1) 0.6474022 2.526864 S( 3 2) 0.6474065 2.526510 S( 3 3) 0.3877579 194.9552 radiated power= 1.0517158E-02 3.2.1 Determining Feed Length The discontinuity to be tested must be fed by microstrip lines of sufficient length to solve for input impedances and subsequently network parameters. It has been determined that sufficienit length shiould be at least 1 guide wavelength(Ag). The guide wavelength is determined by the effective dielectric constant(eff ) which can be obtained from Touchstone data, or two-dimensional simulations by Norm Vandenberg (To be integrated into the package). The length of line required is then: Leed = A = (1) J' *5 )

appendix A-Program Listing The Ienu cliriven fortran prograins are located in the directory: //xenia/users/harolkop/exit_dir/microstrip-dir To accomplish phase 1 of the procedure the program "s2main.ftn" is used. For the multilayer cases The programs "supmain.ftn"(binded with "spint.ftn") and "tlayer.ftn"(binded with "spint.ftn") run phase 1. In order to run phase 2 and find the scattering parameters the program "m4pdisc.ftn" (binded with "linpack.ftn") must be run. Also incluclded in the above cliectoir are the intermediate results from phase 1 for the example shlown in appendix B. The format and output files are entitled ma30-malOO and meandc30-meanc100 respectively.

appendix B-Example of Phase 1 In this appendix a comllete rlln for to create ma50 and meand50 is reproduced. Lin.er name of configuration data file;'ER FREQUENCY (GHz): JTRIES NORMALIZED TO FREE SPACE WAVELENGTH? ( <return> = yes ): Lect units: I MILS mm 4ENSIONS ARE TO BE ENTERED IN MILS:er REAL part of substrate relative dielectric constant zer thickness of substrate: (mils) ter thickness of metal: (mils) ter longitudinal subsection length: (mils) ter transverse subsection length: (mils) ter normalized longitudianl mesh size ter normalized transverse mesh size ter out file for impedance matrix elements: nd50 e of geometry configuration file [NAME] ma50O strate rel. dielectric constant; [ER]: 10.0000 ENSIONS NORMALIZED TO FREE SPACE WAVELENGTH ENSION ENTRY IN MILS: CHANGE UNITS [CU] normalized (mils) (millimeters) quency (GHz) of operation (lambda_o) [F] 50.0000000 ( 236.0570831) ( 5.9958496) ckness of metallization [TD].0211813 ( 5.0000000).1270000) ckness of metallization [T2].0000042 (.0010000).0000254) gitudinal subsection length [DLX].0105907 2.5000000) (.0635000) nsverse subsection length [DLY].0105907 2.5000000) (.0635000) rnalized longitudinal mesh length; [nxn]: 60 nralized transverse mesh width; [nym]: 60 a file for admittance matrix [FI] meand50 ter Variable Name [**] or <return>

appendix C-Example of Phase 2 In this appendix a complete run for to solve for the scattering parameters for a single loop meander line is given. This is followed by typical results for the complete sweep of 30-100 GHz for this example.,e 2********* - of geometry configuration file [NAME] ma50 3r rel. Iielectric constant; [ER]: 10.0000 ENSIONS NORMALIZED TO FREE SPACE WAVELENGTH ENSION ENTRY IN MILS: CHANGE UNITS [CU] normalized (mils) (millimeters) quency (GHz) of operation (lambda o) [F] 50.0000000 236.0570831) ( 5.995849 ckness of cover [TD] 0.0211813 5.0000000) ( 0.12700C0 ckness of metallization [T2] 0.0000042 ( 0.0010000) ( 0.000025gitudinal subsection length [DLX] 0.0105907 2.5000000) ( 0.06350CC' nsverse subsection length [DLY] 0.0105907 2.5000000) ( 0.0635000 th of line /: [WW] 0.0105907 2.5000000) ( 0.0635000 cth of feed line ~ [XLL] 0.3177198 75.0000000) ( 1.905b000 cing of meander line -' ^ s [SM] 0.0423626 10.0000000) ( 0.254000 th of line -= D [DM] 0.0529533 12.5000000) ( 0.317500 ber of periods - = ~ [NP] 1 ective-dle —eectrion s tan [XK] 6.5000000 malized longitudinal mesh length; [nxn] 60 malized transverse mesh width; [nym] 60 a file for admittance matrix [FI] meand50 ter Variable Name [**] or <return> ading impedance vector 000000000000000 000000000000000 000000000000000 000000000000000.00000000000000.00000000000000

cenia/useLs..rokop/rmicro striddisc dir/boxediriscdir/pca-ki/-Qi-tm5n3n d1-/ 1.00000000000000 ).00000000000000 1.00000000000000 ).00000000000000:.00000000000000.00000000000000;.00000000000000.00000000000000.00000000000000.00000000000000.00000000000000.00000000000000.00000000000000.00000000000000.00000000000000.00000000000000.00000000000000.00000000000000.00000000000000.00000000000000.00000000000000.00000000000000.00000000000000.00000000000000 NNING sitions of x-current 0 0 0 0 0 ) ) 0 0 0 0 0 0 0

;xenia/users /haL,.. /microst rip_dir/midiscd ldisc_ dir/boxeddisc_dir/pcaD//git h//tmba / 38 0 59 0 10 0 11 0 12 0 03 0 4 0 50 60 70 80 90 00 10 20 30 40 50 60 70 80 90 00 10 20 30 50 0 O 3 -5 3 -5 -5 -5 )sitions of y-current -4 -3 -2 -1 0 -4 -3 -2 -1 0 RFORMING MATRIX INVERSION TRIX RECIPROCAL CONDITION = 1.5306330E-04 RFORMING BACKSUBSTITUTION (even) RFORMING BACKSUBSTITUTION (odd) 3[S11]= 4.0747445E-02 AND MAG[S12] = 0.9879416 r[S11]= 134.5769 AND ANG[S12] = 231.7558 JER RADIATED= 2.2311091E-02

xenia/users/haroko,- crostrip_dir/mdildiscdir/boxediscdi/boxeddiscdir/pca fd//itm ~ n3~_t/ ostrate rel. dielectric constant; [ER]: 10.0000 1ENSIONS NORMALIZED TO FREE SPACE WAVELENGTH IENSION ENTRY IN mm: CHANGE UNITS [CU] (mils) (millimeters) ickness of cover [TD] ( 5.0000000) (.1270000) Lckness of metallization [T2] (.0010000) (.0000254) ith of line [WW] ( 2.5000000) ( 0.0635000) icing of meander line [SM] ( 10.0000000) ( 0.2540000) )th of line [DM] ( 12.5000000) ( 0.3175000) nber of periods [NP] 1 =20 GHz ~TRIX RECIPROCAL CONDITION = 2.5610888E-04.RFORMING BACKSUBSTITUTION (even):RFORMING BACKSUBSTITUT ION (odd) ~G[Sll]= 0.1808927 AND MAG[S12] = 0.9005098 IG[S1l]= 188.5342 AND ANG[S12] = -53.39265 )WER RADIATED= 0.1563600 1 GHz,TRIX RECIPROCAL CONDITION = 1.6047527E-05 IRFORMING BACKSUBSTITUTION (even),RFORMING BACKSUBSTITUTION (odd),G[S11]= 5.8720998E-02 AND MAG[S12] = 0.9951735 G[S11]= 220.3089 AND ANG[S12] = -49.98627 WER RADIATED= 6.1816573E-03 22 GHz TRIX RECIPROCAL CONDITION = 3.2087517E-04 RFORMING BACKSUBSTITUTION (even) RFORMING BACKSUBSTITUTION (odd) G[S11]= 7.4090175E-02 AND MAG[S12] = 0.9915835 G[S11]= 215.5480 AND ANG[S12] = -53.55463 WER RADIATED= 1.1272788E-02 25 GHz TRIX RECIPROCAL CONDITION = 1.9552899E-03 RFORMING BACKSUBSTITUTION (even) RFORMING BACKSUBSTITUTION (odd) s[S11]= 7.2082400E-02 AND MAG[S12] = 0.9917600 s[S11]= 208.8148 AND ANG[S12] = -61.66417 WER RADIATED= 1.1216342E-02 30 Ghz TRIX RECIPROCAL CONDITION = 4.0396084E-03 RFORMING BACKSUBSTITUTION (even) RFORMING BACKSUBSTITUTION (odd) J[S11]= 7.4191026E-02 AND MAG[S12] = 0.9944218 3[S11]= 195.8359 AND ANG[S12] = -73.45045 NER RADIATED= 5.6208968E-03

xenia/users/harokop/micr _ _p_d /mrdisc__dAl2diss c_dir/boxeddisc_dir/pc aD//9i -/tm-rr_3dl / =35 GHz kTRIX RECIPROCAL CONDITION = 1.9900473E-03 _RFORMING BACKSUBSTITUTION (even) _ RFORMING BACKSUBSTITUTION (odd) kG[S11]= 7.4015193E-02 AND MAG[S12] = 0.9920819 qG[Sll]= 181.7664 AND ANG[S12] = -87.64284 DWER RADIATED= 1.0295272E-02 =40 Ghz \TRIX RECIPROCAL CONDITION = 1.0902056E-04.]RFORMING BACKSUBSTITUTION (even)'RFORMING BACKSUBSTITUTION (odd) kG[S11]= 5.9039339E-02 AND MAG[S12] = 0.9884265 IG[S11]= 169.8870 AND ANG[S12] = 259.2616 )WER RADIATED= 1.9527435E-02 15 Ghz JTRIX RECIPROCAL CONDITION = 3.4132474E-03,RFORMING BACKSUBSTITUTION (even) iRFORMING BACKSUBSTITUTION (odd) ~G[S11= 5.5954035E-02 AND MAG[S12] = 0.9912730 IG[Sll]= 154.9192 AND ANG[S12] = 245.9838 )WER RADIATED= 1.4246881E-02,0 Ghz,TRIX RECIPROCAL CONDITION = 6.8178358E-03 RFORMING BACKSUBSTITUTION (even) RFORMING BACKSUBSTITUTION (odd).G[S11]= 5.5380952E-02 AND MAG[S12] = 0.9878620 G[S11]= 138.8215 AND ANG[S12] = 234.7185 WER RADIATED= 2.1061599E-02 5Ghz TRIX RECIPROCAL CONDITION = 8.2700104E-03 RFORMING BACKSUBSTITUTION (even) RFORMING BACKSUBSTITUTION (odd) G[Sll]= 4.4583641E-02 AND MAG[S12] = 0.9840499 G[Sll]= 124.3158 AND ANG[S12] = 217.9195 WER RADIATED= 2.9658198E-02 7.5 RIX RECIPROCAL CONDITION = 4.8110415E-03 RFORMING BACKSUBSTITUTION (even) RFORMING BACKSUBSTITUTION (odd) G[Sll]= 3.7729446E-02 AND MAG[S12] = 0.9849458 G[Sll]= 118.2313 AND ANG[S12] = 213.5416 WER RADIATED= 2.8458178E-02

Ienia/users/harokop/mricrostrip_c_ -,'i. c 1_ cdiAgldisc_ dir/boxeddisc_dir /pca_f//gitn an3l_g_dt/ 60 Ghz %TRIX RECIPROCAL CONDITION = 3.8664252E-03 ~ RFORMING BACKSUBSTITUTION(even). RFORMING BACKSUBSTITUTION (odd) lG[Sll]= 1.2065395E-02 AND MAG[S12] = 0.9909073 JG[Sll]= -30.98552 AND ANG[S12] = 209.2525 )WER RADIATED= 1.7957270E-02;5 GHz iTRIX RECIPROCAL CONDITION = 5.4558483E-04'RFORMING BACKSUBSTITUTION (even):RFORMING BACKSUBSTITUTION (odd),G[S11]= 1.6343145E-02 AND MAG[S12] = 0.9883375 [G[Sll]= -59.48501 AND ANG[S12] = 189.5378 MWER RADIATED= 2.2921979E-02 0 GHz,TRIX RECIPROCAL CONDITION = 3.6973350E-03 RFORMING BACKSUBSTITUTION (even) RFORMING BACKSUBSTITUTION (odd) G[Sll]= 1.6259484E-02 AND MAG[S12] = 0.9801534 G[Sll]= -81.59840 AND ANG[S12] = 179.0910 WER RADIATED= 3.9034903E-02 75 GHz TRIX RECIPROCAL CONDITION = 1.9371262E-03 RFORMING BACKSUBSTITUTION (even) RFORMING BACKSUBSTITUTION (odd) G[S11]= 2.1936961E-02 AND MAG[S12] = 0.9757098 G[S11]= 55.68557 AND ANG[S12] = 161.7494 WER RADIATED= 4.7509134E-02 80 Ghz tRIX RECIPROCAL CONDITION = 7.2480100E-03.RFORMING BACKSUBSTITUTION (even) RFORMING BACKSUBSTITUTION (odd) [Sll]= 4.8603762E-02 AND MAG[S12] = 0.9644873 J[Sll]= 36.33909 AND ANG[S12] = 144.8380 4ER RADIATED= 6.7402005E-02 ) GHz [RIX RECIPROCAL CONDITION = 7. 594517 4E-03 IFORMING BACKSUBSTITUTION (even) (FORMING BACKSUBSTITUTION (odd) [Sll]= 0.1462795 AND MAG[S12] = 0.9353204;[Sll]= 4.834428 AND ANG[S12] = 110.3224

,/users/harokop/microstrip_dir/..- _.i-..c_d1i gldisc_dir/boxeddisc dir/pc aDfl//rcfiitrnn3 diM / ~R RADIATED= 0.1037779 95 GHz ATRIX RECIPROCAL CONDITION = 1.1382813E-03 ERFORMING BACKSUBSTITUTION (even) ERFORMING BACKSUBSTITUTION (odd) kG[Sll]= 0.2516062 AND MAG[S12] = 0.9040772 qG[Sll]= -9.004583 AND ANG[S12] = 93.42374 DWER RADIATED= 0.1193387 l00 kTRIX RECIPROCAL CONDITION = 9.4958367E-03 2RFORMING BACKSUBSTITUTION (even):RFORMING BACKSUBSTITUTION (odd) [G[S11]= 0.3620355 AND MAG[S12] = 0.8447164 IG[S11]= -24.87141 AND ANG[S12] = 75.18895 )WER RADIATED= 0.1553844

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