100 ' ********************************* 110 ' * IBM PC BASIC VERSION A3.30 * 120 ' * FILE NAME "FRESNE" * 130 ' * FRESNEL ZONE THOREM * 140 ' * 1987/10 I.KATO * 150 ' ********************************* 160 KEY OFF:CLS:SCREEN 9 170 COLOR 14 180 DIM RL(30),VRL(30) 190 DATA "2.2","4.0","4.7","6.0","11.7" 200 FOR I=1 TO 5:READ FR$(I):NEXT 210 LOCATE 1,1:PRINT "[IETM 5] FRESNEL ZONE THOREM":COLOR 7 220 PRINT "A radio wave radiated from a point source spreads out spherically in all" 230 PRINT "directions. In the figure, a perpendicular plane to the transmit-receive path" 240 PRINT TAB(25)"TR, is examined, where concentric circles are locuses" 250 PRINT TAB(25)"of path differences relative to the direct path. TR," 260 PRINT TAB(25)"in trems of multiple of half wave length (WL/2)." 270 PRINT TAB(25)"As proven by Huygens, each of ring zones, m1, m2, m3," 280 PRINT TAB(25)"etc., originates the secondary radiation. At the" 290 PRINT TAB(25)"receiving point R, reradiations from the adjoining" 300 PRINT TAB(25)"zones arrive out-of-phase and cancel each other, while" 310 PRINT TAB(25)"those from every other zone arrive in phase, resulting" 320 PRINT TAB(25)"in a mutual reinforcement." 330 PRINT TAB(25)"A radius of each zone is" 340 PRINT TAB(25)" FR=SQR(m*WL*D1*(D-D1)/D)" 350 PRINT TAB(25)" where m=1,2,3,...." 360 PRINT "Each zone is called the first Fresnel zone, second Fresnel zone, etc. according to the value of m. It uniquely depends upon a wave length and a distance regardless of the altitude of two sites and a value of k." 370 PRINT "Along a microwave trasmission path in which high-gain directive antenna are adopted, a path clearance larger than 2/3 of the radius of the first Fresnel zone from the top of the obstacles assures free space propagation free from" 380 PRINT "obstacle diffraction loss, as the dominant radiative power is contained therein." 390 GOSUB 1000 400 COLOR 6:LOCATE 23,20:PRINT "----- To proceed: Hit space key -----" 410 COLOR 7:Q$=INKEY$:IF Q$<>" " THEN 410 420 SCREEN 0:CLS:SCREEN 9:COLOR 15 430 LOCATE 1, 1:PRINT "[ITEM 5] [FIRST FRESNEL ZONE RADIUS]":COLOR 7 440 LOCATE 3, 1:PRINT " ----- calculation formula -----" 450 LOCATE 5, 1:PRINT "FIRST FRESNEL ZONE RADIUS : FR=SQR(WL*D1*(D-D1)/D)" 460 LOCATE 6, 1:PRINT "WL(wave length)=3*100/FQ(GHz): D=A-B DISTANCE(km):D1=DISTANCE(km) from POINT A" 470 GOSUB 2000:GOSUB 3000 480 COLOR 6:LOCATE 23,20:PRINT "----- menu: Hit space key -----" 490 COLOR 7:Q$=INKEY$:IF Q$<>" " THEN 490 500 SCREEN 0:CLS:RUN "ME" 1000 ' *********************** 1010 ' * graph draw sub(1) * 1020 ' *********************** 1030 WINDOW SCREEN(0,0)-(100,100) 1040 VIEW(8,56)-(172,203),,5 1050 CIRCLE(50,50),18,7,,,1.5 1060 CIRCLE(50,50),28,7,,,1.5 1070 CIRCLE(50,50),38,7,,,1.5 1080 PAINT(50,85),1,7:PAINT(50,75),2,7:PAINT(50,65),4,7 1090 PSET(50,50),4 1100 LINE(50,9)-( 50,50),7,,&H8888 1110 LINE(0,50)-(100,50),7 1120 LINE(0,50)-( 50,31),7,,&H8888 1130 LINE(0,50)-( 50,19),7,,&H8888 1140 LINE(0,50)-( 50, 9),7,,&H8888 1150 LINE(100,50)-(50,31),7,,&H8888 1160 LINE(100,50)-(50,19),7,,&H8888 1170 LINE(100,50)-(50, 9),7,,&H8888 1180 LINE(50,65)-(80,65),7,,&H8888 1190 LINE(50,75)-(80,75),7,,&H8888 1200 LINE(50,85)-(80,85),7,,&H8888 1210 LINE( 0,60)-(50,60),6,,&H8888: LINE( 0,95)-(100,95),6,,&H8888 1220 COLOR 7 1230 LOCATE 9, 2:PRINT "T" 1240 LOCATE 9,22:PRINT "R" 1250 ' 1260 COLOR 4:LOCATE 11,16:PRINT "m1(1st)" 1270 COLOR 2:LOCATE 12,16:PRINT "m2(2nd)" 1280 COLOR 9:LOCATE 13,16:PRINT "m3(3rd)" 1290 COLOR 6 1300 LOCATE 11,5:PRINT "D1" 1310 LOCATE 14,5:PRINT "D" 1320 COLOR 7:RETURN 2000 ' ******************************* 2010 ' * data input graph draw sub * 2020 ' ******************************* 2030 WINDOW SCREEN(-10,-30)-(110,70) 2040 VIEW(120,126)-(280,266),,5 2050 LINE(-10,60)-(110,60),2 2060 LINE(-10,60)-( 0, 0),2 2070 LINE( 0, 0)-( 10,60),2 2080 LINE( 90,60)-(100,20),2 2090 LINE(100,20)-(110,60),2 2100 PAINT( 0,20),2,2 2110 PAINT(100,40),2,2 2120 FOR I=0 TO 100 2130 Y=SQR(5*I*(100-I)/100)+20/100*I 2140 IF I=0 THEN PSET(0,0) ELSE LINE-(I,Y),3 2150 NEXT 2160 FOR I=0 TO 100 2170 Y=-SQR(5*I*(100-I)/100)+20/100*I 2180 IF I=0 THEN PSET(0,0) ELSE LINE-(I,Y),3 2190 NEXT 2200 LINE(50,10)-(55, 0),7 2210 LINE( 0, 0)-(100,20),4 2220 LINE( 0, 0)-( 0,-20),7,,&H8888 2230 LINE(50, 10)-(50,-20),7,,&H8888 2240 LINE( 0,-15)-(50,-15),7,,&H8888 2250 ' 2260 LINE( 0,65)-(100,65),7,,&H8888 2270 LINE( 0,60)-( 0,70),7,,&H8888 2280 LINE(100,60)-(100,70),7,,&H8888 2290 LOCATE 11, 1:PRINT "FIRST FRESNEL" 2300 LOCATE 12, 1:PRINT "ZONE RADIUS" 2310 LOCATE 13, 1:PRINT " (FR)" 2320 LOCATE 12,17:PRINT "A":LOCATE 15,35:PRINT "B" 2330 LOCATE 12,28:PRINT "FR" 2350 LOCATE 11,21:PRINT "D1":LOCATE 19,26:PRINT "D" 2360 RETURN 3000 ' ******************************* 3010 ' * data input graph draw sub * 3020 ' ******************************* 3030 WINDOW SCREEN(0,0)-(50,50) 3040 VIEW(472,126)-(632,266),,5 3050 FOR J=1 TO 5 3060 FQ(J)=VAL(FR$(J)):WL(J)=3*100/FQ(J) 3070 FOR I=0 TO 50 3080 Y=50-SQR(WL(J)*I*(50-I)/50):IF I=25 THEN YM(J)=Y 3090 IF I=0 THEN PSET(0,50) ELSE LINE-(I,Y),3 3100 NEXT I,J 3110 FOR I=1 TO 50 STEP 10 3120 LINE(0,I)-(50,I),7,,&H8888 3130 NEXT 3140 FOR I=1 TO 50 STEP 10 3150 LINE(I,0)-(I,50),7,,&H8888 3160 NEXT 3170 FOR I=1 TO 5:LINE(0,YM(I))-(25,YM(I)),14,,&H8888:NEXT 3180 LINE(0, 3)-(25, 3),7,,&H8888 3190 LINE(0,48)-(50,48),7,,&H8888 3200 LINE(25,0)-(25,10),7,,&H8888 3210 FOR I=1 TO 5:WL(I)=SQR(WL(I)/2*25*25/50):NEXT 3220 LOCATE 11,39:PRINT "FIRST FRESNEL" 3230 LOCATE 12,39:PRINT "ZONE RADIUS":LOCATE 13,39:PRINT "VALUE" 3240 LOCATE 13,39:PRINT "(25km from A)" 3250 LOCATE 10,64:PRINT "25km" 3260 LOCATE 18,64:PRINT "A-B DISTANCE":LOCATE 19,68:PRINT "50km":COLOR 14 3270 LOCATE 11,53:PRINT USING "###.#m";WL(1) 3280 FOR I=1 TO 4:LOCATE 12+I,53:PRINT USING "###.#m";WL(1+I):NEXT 3290 LOCATE 11,73:PRINT "2GHz" 3300 LOCATE 13,73:PRINT "4HGz" 3310 LOCATE 14,73:PRINT "5GHz" 3320 LOCATE 15,73:PRINT "6GHz" 3330 LOCATE 16,73:PRINT "11GHz" 3340 RETURN