Integrated FSK demodulator with very high sensitivity

This paper presents a fully integrated highly sensitive frequency-shift keying (FSK) demodulator functioning at a modulation factor of 0.5%-0.1% and below. A dual-feedback phase-locked loop approach provides both very high sensitivity and sufficiently large tuning range. Experimental results in TSMC 0.25-/spl mu/m CMOS technology demonstrate that Gaussian FSK signals of a modulation factor down to 0.06% can safely be demodulated.