Chapter 6 / 6.4 / 6.4.10

6.4.10 Power Contained In An FM Wave

Since the amplitude of an FM wave does not vary, the total power contained in the wave is constant and equal to the unmodulated carrier power. Note that the carrier frequency component does not have constant amplitude in an FM wave but increases and decreases as the amplitudes of the sidefrequencies rise and lower. Importantly, however, the sum of these components always remains constant even though their individual amplitudes are continually changing.