• Pre-emphasis: The noise suppression ability of FM decreases with the increase in the frequencies. Thus increasing the relative strength or amplitude of the high frequency components of the message signal before modulation is termed as Pre-emphasis. The Fig3 below shows the circuit of pre-emphasis.

• De-emphasis: In the …

The artificial boosting of the amplitude of higher frequency modulating s/g in FM, emitter is called pre-emphasis.

The process of pre-emphasis is carried out prior to FM process.

The pre-emphasis circuit is basically HPF(RC) before applying it to FM modulator.

As FM increases the capacitive reactance decreases and modulating voltage …