Communications ...

Let m₁(t) and m₂(t) be two message signals and let x₁(t) and x₂(t) be the corresponding modulated version:

Consider two statements:

S₁: When the combined message signal m₁(t) and m₂(t) DSB modulates a carrier A_c cos 2πf_ct, the result is the sum of the DSB amplitude modulated signals x₁(t) and x₂(t)

S₂: When the combined message signal m₁(t) and m₂(t) frequency modulates a carrier, the modulated signal is equal to the sum of x₁(t) and x₂(t).

Which among the above statements are correct?

A transmitter angle modulates the signal using a carrier frequency of 1 kHz.

If the transmitter output is given by x(t) = cos (2π 1100t); then the phase and frequency deviation will be respectively

In SSB modulation system, if signal (cos 30 t) is modulated with a carrier signal of frequency 850 rad/sec then the expression for the lower side band is

Suppose we wish to transmit the signal x(t) = sin 200πt + 2 sin 400πt using a modulation that create the signal g(t) = x(t) sin 400πt. If the product g(t) sin 400πt is passed through an ideal LPF with cutoff frequency 400π and passband gain of 2, the signal obtained at the output of the LPF is

An AM modulator for a single tone modulating signal gives an output :

x(t) = A cos 400 πt + Bcos 380 πt + Bcos 420 πt

The carrier power is 100 W and the efficiency is 40%. The values of A and B are

A carrier wave 20 cos (8π × 10⁶t) is frequency modulated by a modulating signal 2 cos (2π × 10³t) + cos (3π × 10³t) + 5 cos (8π × 10³t). If k_f = 40 kHz/volt then bandwidth of the modulated signal is ________ kHz.