A W-Band Balanced Power Amplifier in 0.1-μm GaAs PHEMT Process

In this paper, a compact W-band four-stage power amplifier MMIC in a commercially available 0.l-μm GaAs PHEMT process is presented. By utilizing balanced structure with on-chip Lange couplers, the presented power amplifier exhibits an average small-signal gain of 15 dB and an average saturated output power of 21.5 dBm (141 mW) from 84 to 100 GHz. A peak saturated output power of 22.3 dBm (170 mW) is achieved at an operating frequency of 88 GHz with a total gate periphery of 0.4 mm at the output stage, resulting in a power density of 425 mW/ mm. The input and output return losses are better than 10 dB across the full W-band. The chip size is 1.78 x 1.15 mm2including all pads.