A 5.6-GHz Class-DE Power Amplifier with Reduced Voltage Stress in 22-nm FDSOI CMOS

Abstract

This paper presents a 5.6 GHz Class-DE power amplifier (PA) with reduced voltage stress compared to classical PA designs. CMOS PAs are susceptible to a number of breakdown phenomena such as drain oxide breakdown and hot-carrier injection (HCI) which can significantly reduce their lifespan. The Class-DE amplifier is a hard-switching device which minimizes voltage-current overlap across the channel which significantly reduces the risk of HCI effects. The PA does not use an RF choke which limits the peak drain voltage to VDD, limiting the risk of drain oxide breakdown. The driver circuit gives a duty cycle below 50% and ensures that each transistor is almost completely off before the other has turned on. The PA achieves 47.9% power-added efficiency, 22.2 dBm output power, and 28.2 dB gain with a single 2.2 V supply voltage. Transient simulations of the PA's drain currents and voltages confirm the low current-voltage overlap which shows that the PA has much less risk of HCI effects than classical PA designs.