Power-Efficient Body-Coupled Self-Cascode LC Oscillator for Low-Power Injection-Locked Transmitter Applications

Improving the efficiency and the power consumption of a RF transmitter in a wireless sensor network is a major design challenge. Unlike conventional transmitter architectures, injection-locked transmitter (ILTX) provides high efficiency with reduced power consumption. The core block of an ILTX is an injection-locked oscillator. Therefore this paper reports a low-voltage low-power injection-locked LC oscillator employing self-cascode structure and body-terminal coupling. Self-cascode structure of the oscillator provides low-voltage and low-power operation while body terminal coupling facilitates low-power operation without degrading voltage headroom. The proposed oscillator has been fabricated using 0.18-μm RF CMOS process. Measurement results indicate that the designed oscillator can operate with a supply voltage as low as 1 V and exhibits 36.75 MHz locking range for an injection signal of 1.29 GHz at 0 dBm. The core oscillator consumes only 2 mW of power that makes the proposed design highly suitable for low-power transmitter applications.