GAMMA-DOSE-EFFECT ON LOW-NOISE ALGAAS INGAAS PHEMT AT MILLIMETER-WAVEFREQUENCY/

Gamma-ray irradiation hardness of a millimeter-wave low noise AlGaAs/I nGaAs pseudomorphic HEMT (PHEMT) is investigated for space-bone applic ations. Gamma-ray is irradiated to a 50 GHz-band monolithic PHEMT low noise amplifier under d.c. biasing, and the change of d.c. and RF perf ormances are investigated. No degradation df RF performances are obser ved up to 10(7) rad even at millimeter-wave frequency band. It suggest s that the PHEMT has over a hundred year of life against gamma-ray irr adiation in the space environment. The small signal gain decrease as l ow as 0.5 dB at 10(8) rad dose. The degradation mechanism is also disc ussed from an equivalent circuit analysis of gamma ray irradiated PHEM Ts S-parameters. (C) 1997 Elsevier Science Ltd.