A K-band power amplifier in 0.18 μm CMOS process with slow-wave structure

A 18-24GHz broadband power amplifier (PA) by 0.18-m CMOS technology is presented in this article. The low loss microstrip line matching technique is used to reduce transmission losses and achieve higher gain, PAE, and enough output power. An improved gain-boosting technique is also included in the PA architecture to improve high-frequency gain and gain flatness. The measurement results show that small-signal gain is large than 18.5dB from 18 to 24GHz, while the gain variation is less than 1.5dB. The maximum PAE is about 18%, and the output P-1dB is 13.1 and 15dBm P-sat.