High-gain, low-noise monolithic HEMT distributed amplifiers up to 60 GHz

Ultra-broad-bandwidth distributed amplifiers with cutoff frequencies of 45 and 60 GHz have been developed utilizing 0.25- mu m AlGaAs and InP cascode HEMTs (high electron mobility transistors) with a mushroom gate profile. A measured gain a high as 10+or-1 dB from 5 to 50 GHz and a gain of 8+or-1 dB from 5 to 60 GHz have been achieved from amplifiers using AlGaAs HEMTs. Amplifiers fabricated on InP HEMT material have demonstrated a gain of 15+or-1 dB from 5 to 50 GHz and 12+or-1 dB from 5 to 60 GHz. The measured noise figure for these amplifiers is approximately 2.5-4 dB in the Ka-band. The measured P/sub 1/ /sub dB/ is around 12.5 dBm at 40 GHz. The chip size is 2.3*0.9 mm/sup 2/.<
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