A 1.2 nJ/bit 2.4 GHz Receiver With a Sliding-IF Phase-to-Digital Converter for Wireless Personal/Body Area Networks Y

Abstract

This paper presents an ultra-low power 2.4 GHz FSK/PSK RX for wireless personal/body area networks. A single-channel phase-trac king RX based on a sliding-IF phase-to-digital conversion (SIF-PDC) loop is proposed to di - rectly demodulate and digitize t he frequency/phase-modulated information. The sliding-IF fr equency plan reduces the power consumption of the multi-phase LO generation. A phase rotat or is adopted in SIF-PDC to guarante e frequency stability, i.e., avoid the frequency pulling by interfere nce or frequency drift. It equiva- lently transforms the RF signal processing from the I/Q amplitude domain to a digital-phase domain, which saves up to nearly 40% on power consumption and relaxes the digital baseband com- plexity. A phase-domain linear model of the propo sed SIF-PDC is presented to analyze the frequency response. Fabricated in a 90 nm CMOS technology, the presented RX consumes 2.4 mW at 2M b p sd a t ar a t e ,i . e . ,1 . 2n J / be fficiency, and achieves a sensitivity of –92 dBm.