engineering recuitment GATE ECE 2023-24 Test Series Communication Systems Amplitude Modulation Conventional Amplitude Modulation
Let c(t) = Ac cos (2πfct) and m(t) = cos (2πfmt). It is given that fc ≫ 5fm. The signal c(t) + m(t) is applied to the input of a non-linear device, whose output vo(t) is related to the input vi(t) as v0(t) = avi(t) + bvi2(t) where a and b are positive constants. The output of the non-linear device is passed through an ideal band-pass filter with center frequency fc and bandwidth 3 fm, to produce an amplitude modulated (AM) wave. If it is desired to have the side band power of the AM wave to be half of the carrier power, then a/b is
1
0.25
2
0.5
3
1
4
2