FM - Carrier swing & factors for deviation in signals

Carrier swing is defined as

Options:

a) The total variation in frequency from the lowest to the highest point
b) Frequency deviation above or below the carrier frequency
c) Width of the side band
d) None of the above

Correct Answer: a) The total variation in frequency from the lowest to the highest point

Explanation:

Carrier swing is defined as the total variation in frequency from the lowest to the highest point. The carrier swing = 2* frequency deviation of the FM signal
= 2* Δω

The amount of frequency deviation in FM signal depends on

Options:

a) Amplitude of the modulating signal
b) Carrier frequency
c) Modulating frequency
d) Transmitter amplifier

Correct Answer: a) Amplitude of the modulating signal

Explanation:

The amount of frequency deviation or variation in FM signal depends on amplitude of the modulating signal. So in case of audio signals, louder is the sound, more is the frequency deviation in the carrier signal and vice versa. The frequency deviation helps in determining the bandwidth of the FM signal.