Saved Bookmarks
| 1. |
A ( sinusoidal ) carrier wave C(t) = A_c sin omega_c t is amplitude modulated by a ( sinusoidal ) message signal m(t) = A_m sin omega_m t Write the equation of the (amplitude) modulated signal. Use this equation to obtain the values of the frequencies of all the sinusoidal waves present in the modulated signal. |
|
Answer» Solution : The equation of the (amplitude) modulated signal is ` C_m(t) [(A_c + A_m SIN omega_m t)] sin omega_c t` This can be REWRITTEN as `C_m(t) = [A_c ( 1+ MU sin omega_m t)] sin omega_c t` Where `mu=A_m //A_c ` = modulation INDEX `:. C_m (t) = A_c sin omega_ct + ( mu A_c)/(2) 2 sin omega_c t` `=A_c sin omega_c t + ( mu A_c)/(2) [ cos (omega_c - omega_m)t- cos ( omega_c + omega_m) t]` These are the three sinusoidal waves present in the amplitude modulated signal. The frequencies of these three waves are 
|
|