Question

A carrier wave of frequency 100 MHz is frequency modulated by a sinusoidal wave of amplitude 20 V and frequency of 100 kHz. If the frequency sensitivity of the modulator is 25 kHz/V, then the approximate bandwidth of FM signal is equal to

• A. 0.5 MHz
• B. 1.2 MHz
• C. 1.1 MHz
• D. 0.6 MHz

Answer 1

The correct option is B 1.2 MHz

$BW=2\left[\Delta f{+}_{|}{f}_m\right]$

$\Delta f=K_f{V}_m=25kHz/V\times 20V=500kHz$

$BW=2[0.5+0.1]\times {10}^6=1.2MHz$