60 GHz 28 nm CMOS transformer-coupled power amplifier for WiGig applications

A 60 GHz power amplifier (PA) based on a 28 nm CMOS technology is presented for WiGig applications. It consists of a two-stage pseudo-differential common-source structure using low-power and low-V_t transistors, capacitive neutralisation for isolation enhancement and integrated transformers for impedance matching, power splitting, power combining and balanced-to-unbalanced transformation purposes. The output-stage transistors have a measured 1 dB output compression point (OCP_{1 dB}) of 10.2 dBm, a 10.2 dB gain and a peak power added efficiency (PAE) as high as 35%. The fabricated PA achieves a 12 dBm OCP_{1 dB}, a 15.3 dB gain and a peak PAE better than 20% while occupying a silicon active area of only 0.037 mm².