A 60 GHz SiGe-HBT power amplifier with 20% PAE at 15 dBm output power

A monolithic power amplifier(PA) operating in the 60 GHz band is presented. The circuit has been designed utilizing an advanced 0.25 mu m SiGe-heterojunction bipolar transistor (HBT) technology, featuring npn transistors with f(T) and f(max) approximate to 200 GHz. A two-stage cascode architecture has been chosen for the implementation. Design techniques and optimization procedure are explained in detail. Measurements show a small signal gain of 18.8 dB and an output power of 14.5 dBm\ under 1 dB gain compression at 61 GHz. At this frequency, the saturated output power is 15.5 dBrn and the peak power added efficiency (PAE) is 19.7%. To our knowledge, this is the highest PAE reported so far for a monolithic 61 GHz PA in SiGe-HBT technology.