Low power radio transmitter

A transmitter consisting of a voltage controlled oscillator (VCO) and power amplifier (PA) for the 400 MHz Medical Implanted Communication System band (MICS) was built in a standard 0.35-μm CMOS process. A push pull architecture was used for both the VCO and the PA. Two off-chip inductors were needed. The design was optimized for 400 μW output power at 3 V supply, which resulted in an efficiency of 26 %. This gives a total power consumption of 1.6 mW, of which the VCO uses about 0.3 mW