A low power front-end receiver design for sphygmus sensor using pulse-repetition period modulation

A novel method to detect human sphygmus by using pulse Repetition Period Modulation (PRPM) under unlicensed Ultra-Wide-Band (UWB) below 1 GHz is proposed in this work. The RF front-end receiver was implemented by TSMC CMOS 0.18 um technology that includes push - pull LNA, sampled MIXER, IF amplifier and common-mode feedback circuit. Total current consumes only 2.02 mA by using current reuse technique twice. Measured maximum conversion gain is about 45 dB and 1dB compression point is -18.56 dBV at 500 kHz IF frequency. Sphygmus signal of trier is detected by front-end receiver successfully and its frequency is about 1.25 Hz.