Low-Power, High-Data Rate 915 MHz Transceiver with Fully Passive Wake-Up Receiver for Biomedical Implants

Abstract

A 915 MHz transceiver has been developed for implantable medical devices. The transceiver offers exceptionally low power consumption while providing a high data rate using injection-locked oscillator. The transceiver utilizes Frequency- Shift-Keying (FSK) modulation at a data rate of 8 Mbit/s to provide wireless link between target implantable device and a central base-station unit operating in the North American Industrial, Scientific and Medical (ISM) frequency band. The circuit features a fully passive wake-up receiver (WuRx) enabling energy harvesting from Radio Frequency (RF) input. The amplitude of the FSK RF signal is controlled low for short distance transmission to further reduce the energy consumption. The transceiver, implemented in 0.13 μm CMOS process, is built on new FSK modulation scheme and based on frequency to amplitude conversion. The WuRx achieves a sensitivity of -53 dBm while the main receiver shows -78 dBm sensitivity. Thanks to the simplified hardware, the receiver dissipates only 640 μW while the transmitter consumes 1.4 mW from 1.2 V supply voltage.