A 21.6dBm CMOS power amplifier using a compact high-k output transformer for X-band application

Abstract

CMOS power amplifier (PA) has advantages in power consumption and integration, while the lower operating voltage limits its output power. An area efficient power combiner needs to be designed to improve the output power of CMOS PA. An X-band integrated PA using 65-nm CMOS bulk technology was presented in this work. The whole PA consists of two differential stages: a one-way drive amplifier and a two-way main amplifier. By employing a compactly designed high-k output transformer, the CMOS PA occupied a small core-area of 0.47×0.57mm2, and delivered 21.6 dBm of measured saturated output power with 23.6% of power-added efficiency at 10 GHz from a 1.2-V power supply. Simultaneously, this PA can operate well in 8∼15 GHz wideband.