A 650-pJ/bit MedRadio Transmitter With an FIR-Embedded Phase Modulator for Medical Micro-Power Networks (MMNs)

Abstract

This paper presents a 400-MHz energy-efficient Medical Micro-power Networks transmitter for neural-muscular signal sensing and stimulation applications. The transmitter can fulfill the transmission requirements defined in the MedRadio band, including the recently added 413-MHz to 457-MHz channels. The half-sine shaped offset-QPSK modulation is adopted to meet the transmission mask requirement while supporting a maximum data rate of 4 Mbps within the 6-MHz channel bandwidth. The signal modulation is performed by the proposed FIR-embedded phase modulator which employs a phase-domain FIR filter to suppress the unwanted side-lobe energy. Fabricated in a 0.18-µm CMOS process, the presented transmitter consumes only 2.6 mW from a 1-V supply, resulting in an energy efficiency of 650 pJ/bit. The measured error vector magnitude is 2.5%.