Wideband FM demodulation by injection-locked division of frequency deviation

摘要

A novel and useful wideband FM demodulator operating across an 8 GHz IF bandwidth for application in low-power, wideband heterodyne receivers. The demodulator includes an n-stage ring oscillator that is injection locked to a wideband input signal. Locking to the input frequency, it divides the FM deviation by n, thereby facilitating as well as reducing the energy required for wideband demodulation. The quadrature-phased output of the ring oscillator is phase correlated using a low-power folded CMOS mixer capable of detecting FM up to 400 Mb/s over a 2-10 GHz IF frequency range.

主权项

1. An FM demodulator circuit for demodulating a wideband FM input signal with a high fractional bandwidth, comprising:
an n-stage frequency dividing injection-locked ring oscillator operative to receive a wideband input signal and provide division of frequency deviation thereof, wherein n is an integer greater than one; and a mixer operative to receive the output of said ring oscillator and to generate a demodulated output signal therefrom.