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- 10 REM REFLECTOR ANTENNA DESIGN
- 20 REM "ANTENNA DESIGN USING PERSONAL COMPUTERS"
- 30 KEY OFF
- 40 CLS
- 50 COLOR 1,0
- 60 PRINT "REFLECTOR ANTENNA DESIGN"
- 70 COLOR 4,0
- 80 PI=3.141593
- 90 DEF FNLOG10(X)=.4343*LOG(X)
- 100 PRINT
- 110 INPUT "WHAT IS THE DISH DIAMETER(meters)";D
- 120 INPUT "WHAT IS THE f/d RATIO";FOD
- 130 INPUT "WHAT IS THE FREQUENCY(MHz)";FMC
- 140 XL=300/FMC
- 150 PRINT "HOW DO YOU WISH TO SPECIFY THE FEED POWER PATTERN:"
- 160 PRINT " 1- COS(TH)**N (N EVEN)"
- 170 PRINT " 2- 3 dB BEAMWIDTH"
- 180 PRINT " 3- 10 dB BEAMWIDTH"
- 190 INPUT IOP
- 200 IF IOP<1 OR IOP>3 THEN GOTO 150
- 210 IF IOP>1 THEN GOTO 260
- 220 INPUT "WHAT IS THE VALUE OF N (2,4,6,8)";N
- 230 IF N<>2 AND N<>4 AND N<>6 AND N<>8 THEN GOTO 220
- 240 COLOR 14,0
- 250 GOTO 370
- 260 IF IOP>2 THEN GOTO 300
- 270 INPUT "WHAT IS THE 3-dB BEAMWIDTH(degrees)";BW
- 280 N=-.693/LOG(COS(BW*PI/360))
- 290 GOTO 320
- 300 INPUT "WHAT IS THE 10-dB BEAMWIDTH(degrees)";BW
- 310 N=-2.3/LOG(COS(BW*PI/360))
- 320 N=2*INT(N/2)
- 330 IF N<2 THEN N=2
- 340 IF N>8 THEN N=8
- 350 COLOR 14,0
- 360 PRINT USING "WILL USE N=#";N
- 370 REM COMPUT APERTURE EFFICIENCY
- 380 F=FOD*D
- 390 Z0=F-D*D/(16*F)
- 400 TH=ATN(D/(2*Z0))
- 410 CTH=COS(TH)
- 420 STH=SIN(TH)
- 430 CTH2=COS(TH/2)
- 440 STH2=SIN(TH/2)
- 450 COT2=CTH2/STH2
- 460 LCT=LOG(CTH2)
- 470 STH22=STH2*STH2
- 480 COT22=COT2*COT2
- 490 MCT=(1-CTH)^3/3
- 500 NCT=(1-CTH^4)/4
- 510 EAP=18*(NCT-2*LCT-MCT-.5*STH*STH)^2*COT22
- 520 IF N=6 THEN EAP=14*(2*LCT+MCT+.5*STH*STH)^2*COT22
- 530 IF N=4 THEN EAP=40*(STH22*STH22+LCT)^2*COT22
- 540 IF N=2 THEN EAP=24*(STH22+LCT)^2*COT22
- 550 REM COMPUTE SPILLOVER EFFICIENCY: TAPER EFFICIENCY
- 560 ES=1-CTH^(N+1)
- 570 ET=EAP/ES
- 580 REM COMPUTE DIRECTIVITY
- 590 D=(PI*D/XL)^2*EAP
- 600 DDB=10*FNLOG10(D)
- 610 BW=SQR(33700!/D)
- 620 PRINT
- 630 PRINT USING "SPILLOVER EFFICIENCY= #.###";ES
- 640 PRINT USING "TAPER EFFICIENCY= #.###";ET
- 650 PRINT USING "APERTURE EFFICIENCY= #.###";EAP
- 660 PRINT USING "DIRECTIVITY= ######.# OR ##.# dB";D,DDB
- 670 PRINT USING "3 dB BEAMWIDTH= ##.## degrees";BW
- 680 PRINT
- 690 COLOR 4,0
- 700 INPUT "CONTINUE(Y,N)";K$
- 710 IF K$<>"N" THEN GOTO 40
- 720 COLOR 7,0
- 730 KEY ON
- 740 END