An X-Band, high performance, SiGe-HBT power amplifier for phased arrays

This paper presents a power amplifier (PA) for X-Band phased arrays using a 0.25 µm SiGe BiCMOS process technology. The PA is composed of two cascode stages using fast SiGe HBTs in common emitter configuration and medium voltage ones in common base configuration to achieve a high gain and a relatively high output power, simultaneously. The designed PA resulted in a measured saturated output power of 23.2 dBm with a power-added-efficiency (PAE) of 28% at 9 GHz. The output compression point (P1dB) of the PA is 22.2 dBm at 9 GHz and more than 20 dBm output power is achieved for a 3 GHz bandwidth centered at 9 GHz. The active chip area without pads is 0.6 mm². The small signal gain of the PA is 25.5 dB at 10 GHz and it is higher than 22.5 dB from 8 to 12 GHz. This is a successful demonstration of the integration of the PAs for X-Band phased arrays in SiGe BiCMOS technology and it achieves a competitive or better performance compared to the other works reported in the literature.