X-Band MMIC Amplifier on GaAs/Si

Abstract

A single-stage MMIC feedback amplifier fabricated on GaAs epitaxially grown on high-resistivity Si (6×10 ohm-cm) will be described. The amplifier had 5.5 dB maximum small signal gain and a 3-dB bandwidth of 8.5 to 11.5 GHz. The performance was limited by the poor quality of the Schottky ba rrier on GaAs/Si. The thermal resistance of the MESFET in this MMIC was measured and found to be considerably lower than that for a comparable unit on a semi-insulating GaAs substrate.