Why is de-emphasis used in FM communications receivers?
For compatibility with transmitters using phase modulation✓Правильный ответ
To reduce impulse noise reception
For higher efficiency
To remove third-order distortion products
Объяснение
A phase modulator inherently produces deviation that rises with modulating frequency, which is the same as pre-emphasized FM. A de-emphasis network in the receiver applies the complementary rolloff, restoring flat audio and cutting the high-frequency noise at the same time.