Question

For a low level AM system, amplifier modulated stage must have _________

(a) harmonic devices

(b) linear devices

(c) non-linear devices

(d) class A amplifiers

The question was posed to me in an international level competition.

This intriguing question originated from Method of Generation of SSB-SC in division SSB Modulation of Analog Communications

Answer 1

Right choice is (b) linear devices

Easy explanation: In low-level modulation, the generation of amplitude modulated signal takes place at low power levels. The generated AM signal is then amplified using a chain of linear amplifiers, which are required to avoid waveform distortion. Thus, linear devices are used in low level amplitude modulated system.