Question

part C: block and circuit diagram*

- ] 24 Diodes 1] 3X Low pass filter, Blw=8:5KHZ, HkHz, 98H2. 3] 2x Bend pass filter o fc = 600kHz, Blw= 8kHz fc = 800kHz, Blw= 10k.Ha 4 Nonlinear device : ylt)=08244(+) 6] Unlimited number capacitors 63 1x local osc. gererates frequancy range from 150kHz → 270kHz Aunlimited number of resistors and transforms a) Design AM modulator and Demodulator to transmit auchio signal 6) Very verify your design by writing all expressions of the generated AM Gignal and recoverd Signal of the o/p of the demochtator. c) Draw the bleek/circuit diagram for your design

Answer 1

The question is about designing an AM modulator and a demodulator circuit for an audio signal of bandwidth 4 kHz. As the bandwidth of the audio signal is very low and most of its power lies within 3.1 kHz we use the SSB-SC modulation scheme to reduce power and bandwidth wastage. The block diagram for modulator and demodulator circuits are given below.

transmit audio (6) Block diagram for Am modulator : : . we have to design am modulator to signal of Bandwidth 4 kHz. . This can be done using SSB-sc The modulator block diagram: modulation scheme . Am Cosa ti fmt I produit . modulator Taclosalifet Local ascillator -90° phase suifter qo° phq se suitter Assinatifet Product : modulator Amsin atent The demodulator Block diagram : USB : cupper side band signal) Input RF signal .. SSB cosatthet - ILPE LPF R1 2SB Clower side band 458er side.band -sinatifet