Demodulation methods and devices for frequency-modulated (FM) signals

Abstract

An apparatus includes a phase modulator configured to modulate a phase of an incoming frequency-modulated signal based on a clock signal to generate a phase-modulated signal, where the clock signal is associated with a clock frequency. The apparatus also includes an etalon configured to receive the phase-modulated signal and generate an output signal based on the phase-modulated signal. The apparatus further includes a detector configured to identify amplitudes associated with a first harmonic of the clock frequency and a first subharmonic of the clock frequency in the output signal. In addition, the apparatus includes a decoder configured to recover information encoded in the incoming frequency-modulated signal based on instantaneous frequency deviations of the incoming frequency-modulated signal, where the instantaneous frequency deviations are identified based on relative amplitudes of the first harmonic and the first subharmonic.

Dependencies are inferred from the claim text.