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- 10 REM ANALYSIS PROGRAM FOR MICROSTRIP ANTENNAS
- 20 REM "ANTENNA DESIGN USING PERSONAL COMPUTERS"
- 30 REM K. CARVER'S CAVITY MODEL
- 40 DIM FLDA(180)
- 50 PI=3.141593
- 60 DEF FNLOG10(X)=.4343*LOG(X)
- 70 KEY OFF
- 80 SCREEN 0,1
- 90 CLS
- 100 COLOR 1,0
- 110 PRINT "MICROSTRIP ANTENNA ANALYSIS"
- 120 COLOR 4,0
- 130 PRINT
- 140 INPUT "TYPE PATCH RESONANT LENGTH(cm)";L1
- 150 INPUT "TYPE PATCH WIDTH(cm)";W1
- 160 INPUT "TYPE DIELECTRIC CONSTANT";DC
- 170 INPUT "TYPE SUBSTRATE THICKNESS(cm)";THK
- 180 INPUT "TYPE LOSS TANGENT";LT
- 190 IF LT<1E-08 THEN LT=1E-08
- 200 INPUT "TYPE DISTANCE FROM FEED PT. TO RAD. EDGE(cm)";DIST
- 210 COLOR 14,0
- 220 F1=SQR(1/(1+10*THK/W1))
- 230 REM EFFECTIVE DIELECTRIC CONSTANT
- 240 EDC=(DC+1)/2+(DC-1)/2*F1
- 250 REM AW=2*L1*SQR(EDC)
- 260 AW=2.08*L1*SQR(DC)
- 270 REM WALL CONDUCTANCE
- 280 GWL=8.360001E-03*W1/AW
- 290 REM EFFECTIVE LENGTH EXTENSION
- 300 K=.412*((EDC+.3)/(EDC-.258))*((W1/THK+.262)/(W1/THK+.813))
- 310 REM WALL SUSCEPTANCE
- 320 BWL=.01668*K*(L1/AW)*EDC
- 330 F=.7747+.5977*(W1/L1-1)-.1638*(W1/L1-1)^2
- 340 ALR=-2362*THK*BWL*F/(AW*W1)
- 350 ALI=2362*THK*GWL*F/(AW*W1)
- 360 KPR=ALR*L1
- 370 KPI=ALI*L1
- 380 DEL0=0
- 390 DELI=0
- 400 FOR N=1 TO 4
- 410 P=2*KPR*(PI-DEL0)+2*KPI*DEL1
- 420 Q=KPR*KPR-KPI*KPI+DEL1*DEL1-PI*PI+DEL0*(2*PI-DEL0)
- 430 R=2*KPI*(PI-DEL0)-2*KPR*DEL1
- 440 S=2*DEL1*(PI-DEL0)+2*KPI*KPR
- 450 W=(DEL0^3-DEL1^2*DEL0-2*DEL0*DEL1^2)/3
- 460 X=(-DEL1^3+DEL0^2*DEL1+2*DEL0^2*DEL1)/3
- 470 DEL0=(P*Q+R*S)/(Q*Q+S*S)-W
- 480 DEL1=(R*Q-S*P)/(Q*Q+S*S)-X
- 490 NEXT N
- 500 EGR=PI/L1-DEL0/L1
- 510 EGI=-DEL1/L1
- 520 FR=.5*PI*3*EGR/SQR(DC)
- 530 PRINT
- 540 PRINT USING "THE RESONANT FREQUENCY IS ###.###GHz";FR
- 550 Q0=EGR/(2*EGI)
- 560 CAP=(DC*8.85E-12*W1*L1/10000)/(2*THK/100)
- 570 RES=Q0/(2*PI*FR*1E+09*CAP)
- 580 PRINT USING "THE RADIATION RESISTANCE IS ####.## ohms";RES
- 590 RIN=RES*COS(PI*DIST/L1)^2
- 600 PRINT USING "INPUT RESISTANCE AT FEED IS ###.## ohms";RIN
- 610 SD=1/SQR(PI*FR*1E+09*4*PI*5.7)
- 620 QC=THK/100/SD
- 630 QD=1/LT
- 640 X0=1/Q0+1/QC+1/QD
- 650 QT=1/X0
- 660 VSWR=2
- 670 BW=(VSWR-1)/(QT*SQR(VSWR))
- 680 BW=100*BW
- 690 PRINT USING "THE BANDWIDTH IS ##.#%";BW
- 700 PRINT
- 710 COLOR 4,0
- 720 INPUT "DO YOU WANT TO PLOT PATTERNS(Y,N)";IP$
- 730 IF IP$="N" THEN GOTO 1200
- 740 INPUT "E-PLANE(E) OR H-PLANE(H) PATTERN";IP$
- 750 IF IP$="E" OR IP$="H" THEN GOTO 770
- 760 GOTO 740
- 770 FMAX=0
- 780 XK0=2*PI*FR/.3
- 790 AE=XK0*L1/200
- 800 AH=XK0*W1/200
- 810 FOR TH=0 TO 90
- 820 IND=TH+90
- 830 THR=TH*PI/180
- 840 STH=SIN(THR)
- 850 FLDA(IND)=1
- 860 IF STH=0 THEN GOTO 890
- 870 IF IP$="E" THEN FLDA(IND)=ABS(COS(AE*STH))
- 880 IF IP$="H" THEN FLDA(IND)=ABS(SIN(AH*STH)*COS(THR)/(AH*STH))
- 890 IF FLDA(IND)>FMAX THEN FMAX=FLDA(IND)
- 900 FLDA(180-IND)=FLDA(IND)
- 910 NEXT TH
- 920 PRINT
- 930 REM NORMALIZE DATA
- 940 FOR TH=0 TO 180
- 950 FM=FLDA(TH)/FMAX
- 960 IF FM<.0316 THEN FM=.0316
- 970 FLDA(TH)=20*FNLOG10(FM)
- 980 NEXT TH
- 990 REM PLOT GRID
- 1000 SCREEN 0,1
- 1010 CLS
- 1020 SCREEN 2,0
- 1030 VIEW (262,20)-(638,188)
- 1040 WINDOW (-1,-1)-(1,1)
- 1050 CIRCLE (0,0),1,,,,.45
- 1060 CIRCLE (0,0),.666,,,,.45
- 1070 CIRCLE (0,0),.333,,,,.45
- 1080 FOR THD=0 TO 150 STEP 30
- 1090 TH=THD*PI/180
- 1100 LINE (COS(TH),SIN(TH))-(-COS(TH),-SIN(TH))
- 1110 NEXT THD
- 1120 PSET (FLDA(0),0)
- 1130 FOR TH=0 TO 180
- 1140 THR=TH*PI/180
- 1150 RAD=FLDA(TH)/30+1
- 1160 LINE -(RAD*COS(THR),RAD*SIN(THR))
- 1170 NEXT TH
- 1180 PRINT USING "&-PLANE PATTERN";IP$
- 1190 GOTO 720
- 1200 INPUT "CONTINUE(Y,N)";ST$
- 1210 IF ST$<>"N" THEN GOTO 80
- 1220 SCREEN 0,1
- 1230 COLOR 7,0
- 1240 KEY ON
- 1250 END