Question

Which statement is true for high level amplitude modulation?

(a) all RF amplifiers are of class A

(b) all RF amplifiers can be nonlinear

(c) minimum RF power is required

(d) maximum RF power is required

I had been asked this question in unit test.

My query is from Instantaneous Frequency and Frequency Modulation in chapter Angle Modulation of Analog Communications

Answer 1

Right choice is (b) all RF amplifiers can be nonlinear

To elaborate: In high level AM, modulation is done at high power of carrier and modulating signal therefore output power is high. Therefore, power amplifiers are not used to boost the carrier and modulating signal. Thus, all RF amplifiers are non-linear.