Question

A message signal of frequency 10 kHz and peak voltage 10 volt is used to modulate a carrier of frequency 1 MHz and peak voltage 20 volt. Determine (a) modulation index (b) the side bands produced.

Answer 1

Here, `v_m = 10kHz, A_m = 10V`
`v_c = 1MHz = 1000 kHz, A_c = 20V`
(a) modulation index, `mu_a = A_m/A_c = 10/20 = 0.5`
(b) The side bands are
`USB = v_c + v_m = 1000 + 10 = 1010 kHz`
`LSB = v_c - v_m = 1000 - 10 = 990 kHz` .