Phase Modulation (PM)

Phase modulation (PM) is a type of angle modulation in which the phase angle of a carrier wave is made to deviate from its reference value by an amount proportional to the instantaneous value of the modulating message signal. The resulting phase-modulated wave is transmitted.

Phase modulation can be expressed using the following general equation for angle modulation:

where

A_c is the carrier amplitude
f_c is the carrier frequency
k_f is the frequency deviation constant in Hz/V
f_m is the frequency of the message signal

Refer to the NI Developer Zone at ni.com/zone for more information about phase modulation.