Differential 2.4‐GHz CMOS power amplifier using stacked NMOS, transformer, and PMOS structures to enhance reliability

Abstract

In this work, we propose a power amplifier using a stacked NMOS, transformer, and a PMOS structure to enhance the reliability of CMOS power amplifiers. The power stage of the amplifier is separated into NMOS and PMOS amplifier stages to moderate the peak voltages at the drains of each NMOS and PMOS. The power generated in the 2 amplifier stages is combined in the transformer, which has 2 primary parts and 1 secondary part. To verify the functionality of the structure, we designed a 2.4‐GHz differential CMOS power amplifier for IEEE 802.11n WLAN applications with 64 quadrature amplitude modulation, 9.6 dB peak‐to‐average power ratio, and a bandwidth of 20 MHz. The designed power amplifier is fabricated using the 180‐nm silicon‐on‐insulator RF CMOS process. The measured maximum linear output power is 17.88 dBm with a gain of 24.34 dB.