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Hiroshi TSUKADA Kunihiko KANAZAWA Yoshiro OISHI Hiroshi TAKENAKA Masahiro NISHIUMA Masahiro HAGIO Masaru KAZUMURA
We have fabricated a 12 GHz-band monolithic microwave integrated circuit amplifier of which the noise level has been reduced down to 1.18-1.35 dB in the frequency range from 11.7 GHz to 12.7 GHz. The excellent characteristics come from the use of low-gate-resistance, low-equivalent-noise-resistance HEMT's which were obtained by using T-getes, and a hi-lo doping profile in an AlGaAs layer.
Masahiro NISHIUMA Shutaro NAMBU Masahiro HAGIO Gota KANO
A new GaAs monolithic negative feedback amplifier using a dual-gate MESFET for A.G.C. function has been developed. Such a low NF value as 1.8 to 2.5 dB with a gain of 10 to 12 dB over a frequency range of 50 to 2,000 MHz has been obtained. The gain reduction of about 30 dB was achieved over the same frequency range by means of the second-gate bias. A comparison of the performance between negative feedback amplifiers using a dual-gate FET and a single-gate FET is also discussed.