Decade bandwidth single and cascaded travelling wave medium power amplifiers using sige hbts

This paper presents two integrated class-A travelling wave medium power amplifiers employing 0.35μm SiGe HBT process. The first amplifier realized is a 1.3×1mm² device comprising of a single-stage configuration using a single transistor that exhibits an average small-signal gain of 7dB and power level of 14dBm between 0.25 to 2.5GHz while maintaining power-added efficiency in the range 30% to 10%. The second amplifier is 1.8×2.3mm² device comprising of a driver stage cascaded with two identical amplifier stages in a parallel configuration whose outputs are combined together to enhance the devices output power by 3dB across the wideband frequency range. This amplifier´s unique topology is implemented using a version of the first amplifier. The amplifier´s measured output power was approximately 18dBm, the average small-signal gain was 21dB, and efficiency between 30% to 10% across 0.2-2.2GHz.