Title :
A 5-MHz IF digital FM demodulator
Author :
Park, Jaejin ; Joe, Eurho ; Choe, Myung-Jun ; Song, Bang-Sup
Author_Institution :
Samsung Electron., Kiheung, South Korea
fDate :
1/1/1999 12:00:00 AM
Abstract :
Key requirements for digital frequency-modulation (FM) demodulators are wide spurious-free dynamic range in the intermediate-frequency quantizer, linear-phase passband filtering, and accurate frequency discrimination. The proposed FM demodulator implemented digitally achieves high linearity by numerical differentiation performed at a 112× oversampling rate, suppresses adjacent channels by placing zeros of the SINC function on them, and rejects amplitude-modulation (AM) components by numerical division. A 5-MHz FM demodulator integrated with a fourth-order bandpass delta-sigma front end exhibits 74.7 dB signal-to-noise ratio, -80.7 dB total harmonic distortion, and 61 dB AM rejection within a 9-kHz message bandwidth. The 0.65-μm CMOS chip occupies 3.5×3.5 mm2 of active area and consumes 180 mW with 4-V supply when clocked at 20 MHz
Keywords :
CMOS integrated circuits; demodulators; frequency modulation; mixed analogue-digital integrated circuits; 0.65 micron; 180 mW; 4 V; 5 MHz; 9 kHz; AM rejection; CMOS chip; IF digital FM demodulator; adjacent channel suppression; bandpass delta-sigma front end; dynamic range; frequency discrimination; intermediate-frequency quantizer; linear phase passband filtering; message bandwidth; numerical differentiation; numerical division; signal-to-noise ratio; sinc function; total harmonic distortion; Bandwidth; Demodulation; Digital filters; Dynamic range; Filtering theory; Frequency; Linearity; Passband; Signal to noise ratio; Total harmonic distortion;
Journal_Title :
Solid-State Circuits, IEEE Journal of
