Ganesh Kathiresan

A 1 V Wireless Transceiver for an Ultra-Low-Power SoC for Biotelemetry Applications

This paper presents a 1 V RF transceiver for biotelemetry and wireless body sensor network (WBSN) applications, realized as part of an ultra low power system-on-chip (SoC), the Sensiumtrade. The transceiver utilizes FSK/GFSK modulation at a data rate of 50 kbit/s to provide wireless connectivity between target sensor nodes and a central base-station node in a single-hop star network topology operating in the 862-870 MHz European short-range-device (SRD) and the 902-928 MHz North American Industrial, Scientific & Medical (ISM) frequency bands. Controlled by a proprietary media access controller (MAC) which is hardware implemented on chip, the transceiver operates half-duplex, achieving -102 dBm receiver input sensitivity (for 1E-3 raw bit error rate) and up to -7 dBm transmitter output power through a single antenna port. It consumes 2.1 mA during receive and up to 2.6 mA during transmit from a 0.9 to 1.5 V supply. It is fabricated in a 0.13 mum CMOS technology and occupies 7 mm2 in a SoC die size of 4 times 4 mm2.

A 1V, Micropower System-on-Chip for Vital-Sign Monitoring in Wireless Body Sensor Networks

This paper describes the integration of a system solution with a full-custom hardware MAC, digital microprocessor core and I/O peripherals, on-chip memory, micropower ADC, wireless transceiver and custom sensor interfaces. This SoC platform device is capable of achieving ubiquitous medical monitoring when interfaced to appropriate body worn sensors, and represents state-of-the art in terms of functionality and ultra- low-power consumption.

A low voltage bulk driven downconversion mixer core

This paper describes a CMOS mixer core, operating at 1 GHz, where the RF signal is input via the bulk. The advantages of a bulk driven mixer are low power supply voltages and low power consumption. Simulations have confirmed that a power supply as low as 1 V can be used to power the mixer core, which drains approximately 1.6 mA. Although the mixer core consumes very low power, it still provides reasonable gain as well as linearity.