Reduction in harmonic distortion through use of aperiodic timing in frequency demodulation

It is demonstrated, theoretically and experimentally, that aperiodic timing based on the FM signal, as opposed to periodic timing based on a reference carrier, can lead to a significant reduction in harmonic distortion in an FM demodulator based on an exclusive OR gate and a sample and hold structure. A 20-dB improvement in harmonic distortion can be readily achieved.