* SPICE netlist
XU1 N008 N001 5V -5V N007 OP27 ;pnba In+)In-)V+)V-)OUT
V1 5V 0 5
V2 -5V 0 -5
C1 N001 0 100p
R1 N007 N001 100k
R2 0 N008 100k
R3 N007 N008 100k
R4 N005 N007 47k
R5 N005 N015 47k
V3 N015 0 SINE(0 5 40k)
XU2 0 N005 5V -5V N011 OP27 ;pnba In+)In-)V+)V-)OUT
R6 N011 N005 20k
DN4148 N011 N012 D
R7 N012 0 10k
C2 N012 0 47n
R8 N004 N009 10k
R9 Vout N004 40k
XU4 NC_01 N004 5V -5V Vout OP37 ;pnba In+)In-)V+)V-)OUT
CAntenna N001 0 23p
R10 N014 N002 10k
C3 N014 0 63n
XU5 N014 N006 5V -5V N010 OP27 ;pnba In+)In-)V+)V-)OUT
R11 N010 N006 40k
R12 N006 0 20k
C5 N013 N012 4.7n
R13 N013 0 1.7Meg
XU3 N013 N002 5V -5V N002 OP27 ;pnba In+)In-)V+)V-)OUT
XU6 N010 N003 5V -5V N009 OP27 ;pnba In+)In-)V+)V-)OUT
R14 N009 N003 20k
R15 N003 0 5k
R16 N016 0 47k
R17 N017 N016 100k
R18 N018 0 4.7k
C4 N018 0 1n
R19 N017 P001 4.7k
C6 P001 N018 1n
XU7 N018 N016 5V -5V N017 UA741 ;pnba In+)In-)V+)V-)OUT
.tran 100ms
.wave "output.wav" 16 44.1k V(Vout)
.include UA741.301

* LTspice schematic (.asc)
Version 4
SHEET 1 3040 944
WIRE -1152 -280 -1152 -360
WIRE -1152 -280 -1296 -280
WIRE -1072 -280 -1152 -280
WIRE 160 -248 16 -248
WIRE 1200 -248 1072 -248
WIRE 1408 -248 1376 -248
WIRE 1520 -248 1488 -248
WIRE -672 -232 -768 -232
WIRE -1152 -200 -1152 -280
WIRE -1104 -200 -1152 -200
WIRE 640 -200 448 -200
WIRE 1520 -200 1520 -248
WIRE -992 -184 -992 -280
WIRE -992 -184 -1040 -184
WIRE -896 -184 -992 -184
WIRE -1152 -168 -1264 -168
WIRE -1104 -168 -1152 -168
WIRE 1072 -168 1072 -248
WIRE 1088 -168 1072 -168
WIRE 1376 -168 1376 -248
WIRE 1392 -168 1376 -168
WIRE -1264 -152 -1264 -168
WIRE 16 -152 16 -248
WIRE 64 -152 16 -152
WIRE 448 -152 448 -200
WIRE 496 -152 448 -152
WIRE 1264 -152 1152 -152
WIRE 1376 -152 1376 -168
WIRE 1376 -152 1344 -152
WIRE 1520 -152 1520 -200
WIRE 1520 -152 1456 -152
WIRE -816 -136 -816 -184
WIRE -768 -136 -768 -232
WIRE -768 -136 -816 -136
WIRE -704 -136 -768 -136
WIRE 160 -136 160 -248
WIRE 160 -136 128 -136
WIRE 320 -136 160 -136
WIRE 1088 -136 560 -136
WIRE -592 -120 -592 -232
WIRE -592 -120 -640 -120
WIRE -464 -120 -528 -120
WIRE -64 -120 -464 -120
WIRE 64 -120 0 -120
WIRE 320 -120 320 -136
WIRE 336 -120 320 -120
WIRE 496 -120 416 -120
WIRE -816 -104 -816 -136
WIRE -704 -104 -736 -104
WIRE 1200 -72 1200 -248
WIRE 1200 -72 1152 -72
WIRE -1152 -56 -1152 -168
WIRE -1072 -56 -1152 -56
WIRE -992 -56 -992 -184
WIRE 640 -56 640 -200
WIRE 640 -56 560 -56
WIRE -736 -8 -736 -104
WIRE -896 56 -896 -104
WIRE -800 232 -960 232
WIRE -960 296 -960 232
WIRE -800 296 -960 296
WIRE -720 312 -720 232
WIRE -720 312 -736 312
WIRE -800 328 -848 328
WIRE -848 392 -848 328
WIRE -848 392 -912 392
WIRE -784 392 -848 392
WIRE -848 408 -848 392
WIRE -880 472 -912 472
WIRE -848 472 -880 472
FLAG -1520 -376 0
FLAG -1424 -376 0
FLAG -1424 -456 5V
IOPIN -176 -128 In
FLAG -1520 -456 -5V
IOPIN -272 -128 In
FLAG -1072 -152 -5V
IOPIN 176 176 In
FLAG -1072 -216 5V
IOPIN 176 112 In
FLAG -1360 -280 0
FLAG -1264 -72 0
FLAG -896 136 0
FLAG -672 -88 -5V
IOPIN 576 240 In
FLAG -672 -152 5V
IOPIN 576 176 In
FLAG -736 -8 0
FLAG -464 -56 0
FLAG -528 -40 0
FLAG 1424 -120 -5V
IOPIN 2672 208 In
FLAG 1424 -184 5V
IOPIN 2672 144 In
FLAG -1216 -360 0
FLAG 1520 -200 Vout
IOPIN 2768 128 Out
FLAG 416 -56 0
FLAG 528 -104 -5V
IOPIN 1776 224 In
FLAG 528 -168 5V
IOPIN 1776 160 In
FLAG 560 24 0
FLAG 0 -40 0
FLAG 96 -104 -5V
IOPIN 1344 224 In
FLAG 96 -168 5V
IOPIN 1344 160 In
FLAG 1120 -184 5V
IOPIN 2368 144 In
FLAG 1120 -120 -5V
IOPIN 2368 208 In
FLAG 1152 8 0
FLAG -960 376 0
FLAG -880 472 0
FLAG -768 280 5V
IOPIN 480 608 In
FLAG -768 344 -5V
IOPIN 480 672 In
SYMBOL OpAmps\\OP27 -1072 -248 R0
SYMATTR InstName U1
SYMBOL voltage -1424 -472 R0
SYMATTR InstName V1
SYMATTR Value 5
SYMBOL voltage -1520 -472 R0
SYMATTR InstName V2
SYMATTR Value -5
SYMBOL cap -1296 -296 R90
SYMATTR InstName C1
SYMATTR Value 100p
SYMBOL res -976 -296 R90
SYMATTR InstName R1
SYMATTR Value 100k
SYMBOL res -1248 -56 R180
SYMATTR InstName R2
SYMATTR Value 100k
SYMBOL res -976 -72 R90
SYMATTR InstName R3
SYMATTR Value 100k
SYMBOL res -800 -200 R90
SYMATTR InstName R4
SYMATTR Value 47k
SYMBOL res -800 -120 R90
SYMATTR InstName R5
SYMATTR Value 47k
SYMBOL voltage -896 40 R0
SYMATTR InstName V3
SYMATTR Value SINE(0 5 40k)
SYMBOL OpAmps\\OP27 -672 -184 R0
SYMATTR InstName U2
SYMBOL res -576 -248 R90
SYMATTR InstName R6
SYMATTR Value 20k
SYMBOL diode -592 -104 R270
SYMATTR InstName N4148
SYMBOL res -544 -136 R0
SYMATTR InstName R7
SYMATTR Value 10k
SYMBOL cap -480 -120 R0
SYMATTR InstName C2
SYMATTR Value 47n
SYMBOL res 1360 -168 R90
SYMATTR InstName R8
SYMATTR Value 10k
SYMBOL res 1504 -264 R90
SYMATTR InstName R9
SYMATTR Value 40k
SYMBOL OpAmps\\OP37 1424 -216 R0
SYMATTR InstName U4
SYMBOL cap -1152 -376 R90
SYMATTR InstName Antenna
SYMATTR Value 23p
SYMBOL res 432 -136 R90
SYMATTR InstName R10
SYMATTR Value 10k
SYMBOL cap 400 -120 R0
SYMATTR InstName C3
SYMATTR Value 63n
SYMBOL OpAmps\\OP27 528 -200 R0
SYMATTR InstName U5
SYMBOL res 544 -152 R0
SYMATTR InstName R11
SYMATTR Value 40k
SYMBOL res 544 -72 R0
SYMATTR InstName R12
SYMATTR Value 20k
SYMBOL cap 0 -136 R90
SYMATTR InstName C5
SYMATTR Value 4.7n
SYMBOL res -16 -136 R0
SYMATTR InstName R13
SYMATTR Value 1.7Meg
SYMBOL OpAmps\\OP27 96 -200 R0
SYMATTR InstName U3
SYMBOL OpAmps\\OP27 1120 -216 R0
SYMATTR InstName U6
SYMBOL res 1136 -168 R0
SYMATTR InstName R14
SYMATTR Value 20k
SYMBOL res 1136 -88 R0
SYMATTR InstName R15
SYMATTR Value 5k
SYMBOL res -976 280 R0
SYMATTR InstName R16
SYMATTR Value 47k
SYMBOL res -704 216 R90
SYMATTR InstName R17
SYMATTR Value 100k
SYMBOL res -928 376 R0
SYMATTR InstName R18
SYMATTR Value 4.7k
SYMBOL cap -864 408 R0
SYMATTR InstName C4
SYMATTR Value 1n
SYMBOL res -736 296 R0
SYMATTR InstName R19
SYMATTR Value 4.7k
SYMBOL cap -720 376 R90
SYMATTR InstName C6
SYMATTR Value 1n
SYMBOL OpAmps\\opamp2 -768 248 R0
SYMATTR InstName U7
SYMATTR Value UA741