Disadvantages of using balanced slope detector for demodulation of FM signal

What are the disadvantages of using balanced slope detector for demodulation of FM signal?

Options:

a) The detector operates only for small deviation in frequency
b) Low pass filter of the detector produces distortion in the detection
c) Both a) and b)
d) None of the above

Correct Answer: c) Both a) and b)

Explanation:

The linear characteristics of the detector are limited to only small deviations in the frequency. So the distortions occur due to non linear characteristics of the detector at higher deviations in frequency. The low pass RC filter of the detector is not purely band limited so it introduces distortions. But the circuit may be designed to keep the distortions minimum possible with adequate operation.