High-Efficiency Microwave and mm-Wave Stacked Cell CMOS SOI Power Amplifiers

Abstract

Design and implementation of high-efficiency microwave and mm-wave CMOS silicon-on-insulator (SOI) power amplifiers (PAs) based on a stacked cell approach is presented. Two stacked cell PAs have been implemented in GlobalFoundries 45-nm CMOS SOI technology. The first PA operating at K-band (24–28 GHz) is designed with three stacked triple Cascode cells. Each cell uses three standard transistors with separate layout. At 24 GHz, the K-band PA biased under a supply voltage of 10.8 V measures a maximum linear power gain of 13 dB, a saturated output power $P _{\mathrm {SAT}}$ of 25.3 dBm, a −1-dB output power $P _{1\mathrm {dB}}$ of 23.8 dBm, and a peak power-added efficiency (PAE) of 20%. The second PA targeted at U-band frequencies is designed with two stacked triple Cascode cells. Transistors in each cell have a combined layout that reduces parasitic capacitances, leading to significant improvement in the PAE at mm-wave frequencies. The U-band PA operates from 42 to 54 GHz. At 46 GHz, and under a supply voltage of 6 V, it measures a saturated output power ( $P _{\mathrm {SAT}}$ ) of 22.4 dBm, a linear gain of 17.4 dB, and an unprecedented peak PAE of 42%.