A 60 GHz 24.5 dBm wideband distributed active transformer power amplifier on 250 nm BiCMOS

This paper presents a 60 GHz differential single-stage power amplifier IC with extrapolated 24.5 dBm output power and 12.9 % power added efficiency at 1 dB compression. The circuit is based on distributed amplification with four parallel cascode stages and power combination with a transformer. It shows a 3 dB gain bandwidth of 12 GHz from 51 GHz to 63 GHz with maximum power gain of 12.3 dB at 58 GHz. It consumes 600 mA from a 3.3 V supply and was fabricated in a 250 nm SiGe BiCMOS technology with peak fT and fmax of 180 GHz and 220 GHz, respectively. The high linearity of the circuit exceeds the capabilities of the available measurement instrumentation. A maximum output power of 16.5 dBm has been observed; extrapolation from the measured data and matching simulated performance allow predicting an output power of 24.5 dBm at 1 dB compression. This value, to the best knowledge of the authors, would be the highest reported to date for 60 GHz silicon power amplifiers.