A superheterodyne receiver is receiving a signal from an AM modulator where the

carrier signal has an amplitude Ec and carrier frequency if fc. Frequency of the

information signal is fi. The modulator has following parameters.

• output (load) resistance – RT,

• modulation index – m,

• total amplification through the modulator stages – GT

• During the propagation through the air signal power is attenuated by a factor

GP (GP < 1).

a. Calculate the input power received at the receiver.

b. If the intermediate frequency of the receiver is fIF, what is the maximum RF

bandwidth the device can have if the receiver is not to suffer from image

frequency problem.

c. If the RF bandwidth from part “b” is used and noise density (noise power per

Hz) is N0, calculate the SNR at the input of the receiver. Assume the system

has a LC filter in the IF stage.

d. If the total power amplification through the receiver stages is GR find the

output power of the receiver.

e. If the noise power at the output is 2GR times that at the input of the receiver,

find the NR for the receiver.