79GHz BiCMOS single-ended and differential power amplifiers

This paper presents the performance of 79GHz power amplifiers (PAs) for automotive short range radar (SRR) application. A single-ended four stage common emitter circuit topology and a differential PA with integrated baluns are fabricated using 0.13μm SiGe BiCMOS process. The design and the measured results of the monolithic integrated low-voltage PAs are reported. The 79GHz differential PA, which the design is based on the single-ended PA, delivers 18dBm of maximum output power and 13.5dBm output power at 1dB compression (P_1dB). The differential circuit achieves 21.5dB gain and shows 8.2% of power added efficiency (PAE) from a 1.8V supply voltage at 79 GHz. The power amplifier was fully integrated including matching elements, bias circuit and very small baluns. The chip occupies an area of 0.46mm² and 0.7mm² for the single-ended and differential configuration respectively.