A Low-Power CMOS Class-E Power Amplifier for Biotelemetry Applications

Designing efficient, fully integrated transceivers that could operate from very low supply voltages and for biomedical implantable electronic systems is a major challenge. This paper presents a fully integrated, 2.4 GHz class-E power amplifier (PA), with a class-F driver stage. The circuit was fabricated in a standard 0.18 µm CMOS technology. Measurement results show a maximum drain efficiency of 38 % and a maximum gain of 17 dB. When operating from a 1.2 V supply, the PA delivers an output power of 9 mW with a power-added efficiency (PAE) of 33 %. The supply voltage can go down to 0.6 V with an output power of 2 mW and a PAE of 25 %. The circuit also has a second output to test the effects of using an on-chip filter in low-power designs. This work demonstrates the feasibility of using class-E PAs for short-range, low-power applications.