A Q-BAND MONOLITHIC LINEAR-AMPLIFIER USING ALGAAS GAAS HBTS/

This letter reports on a Q-band monolithic heterojunction bipolar tran sistor (HBT) amplifier demonstrating high gain, efficiency, excellent linearity, and low added phase noise, The amplifier used 40 mu m(2) CB -HBT's in a balanced configuration. The monolithic microwave integrate d circuit (MMIC) amplifier showed a peak gain of 13.5 dB at 38 GHz and a 3-dB bandwidth of 10 GHz. Under class-A bias conditions, the circui t exhibited P-1 dB higher than 15 dBm from 35-41.5 GHz and a peak PAE of 32% at 35 GHz, Two-tone tests showed an IP3 of 30 dBm at 44 GHz and IMD(3) ratios better than 20 dBc at 1-dB gain compression point. Ampl ifier phase noise measurement showed added phase noise of -148 dBc/Hz at 10 kHz away from the carrier at P-1 dB This circuit demonstrates a great potential for the HBT MMIC's for mm-wave high-efficiency linear applications.