A monolithic 24 GHz SiGe HBT power amplifier (PA), with an output 1 dB compression point of 20 dBm, is presented. The circuit is biased from a 5.1 V supply in a class AB mode of operation, resulting in a power added efficiency (PAE) of 14 % at the 1 dB compression point. The SiGe PA has a small-signal gain of 12 dB at 24 GHz, and a return loss of 9.6 dB and 16 dB at the input and output ports, respectively. This SiGe PA leverages the increased voltage swing capabilities associated with the common-emitter / common-base configuration for SiGe HBTs incorporated in a cascode architecture