Frequency Modulation (FM)
Frequency modulation (FM) is a type of angle modulation in which the frequency of a sinusoidal carrier wave deviates from a center frequency by an amount proportional to the instantaneous value of the message signal. In FM, the center frequency is the carrier frequency.
Frequency modulation can be expressed using the general equation for angle modulation.
where
Ac is the carrier amplitude
fc is the carrier frequency
kf is the frequency deviation constant in Hz/V
fm is the frequency of the message signal
Refer to the NI Developer Zone at ni.com/zone for more information about frequency modulation.