Question

DSB-SC (Suppressed Carrier) - Generation Multiplier Carrier Note: Message is 2sin(2nx2x103t) Carrier is 2sin(2x100x103t) Message Using mathematical analysis, predict the frequency spectrum frequency domain) for y(t) in the above Figure DSB-SC Modulator. Sketch both the time domain view and the spectrum in the graphs provided below (Predicted) noting all important amplitudes, strengths and frequencies.

Answer 1

M (t) = 2 sin (2 pi times 2 times 10^3 t) c (t) = 2 sin (2 pi times 100 times 10^3 t) y (t) = m (t) middot c (t) = 4 sin (2 pi times 2 times 10^3 t) middot sin (2 pi times 100 times 10^3 t) = 4 times 1/2 [cos (2 pi times (100 - 2) times 10^3 t) - cos (2 pi times 100 + 2) times 10^3 t)] y (t) = 2 [cos (2 pi times 98 times 10^3 t) - cos (2 pi times 102 times 10^3 t)] y (s) = 2 [1/2 [delta (f - 98 k) + delta (f + 98 k) - 1/2 (delta (f - 102 k) + delta (f + 102 k)]] y (s) = delta (f - 98 k) + delta (f + 98 k) - delta (f - 102 k) - delta (f + 102 k) \r\n spectrum of y (t) waveform of y (t) Note that the above timing axis are not scaled by the same amount.