A low-voltage low-power injection-locked oscillator for wearable health monitoring systems

This paper reports a low-voltage low-power injection-locked oscillator suitable for short range wireless transmitter applications in a wireless body area network (WBAN). Low-power transmitter with high efficiency is a major design challenge for short range wireless communication. Unlike conventional transmitters used for cellular communication, injection-locked transmitter shows reduced power consumption and high transmitter efficiency. The core block of an injection-locked transmitter is an injection-locked oscillator. In this work a low-voltage low-power injection-locked LC oscillator has been designed and fabricated employing self-cascode structure and body-terminal coupling. The proposed oscillator has been realized using 0.18-mu m RF CMOS process. Experimental results indicate that the prototype oscillator can operate with a supply voltage as low as 0.9 V and consumes only 1.4 mW of power. The relatively low-voltage and low-power operation of the design makes it highly suitable for low-power transmitter applications.