100 K uncooled GaAs mesfet amplifier as paramp replacement

Abstract

The characterisation, design and realisation of a low noise GaAs m.e.s.f.e.t. amplifier to replace a narrow band parametric amplifier at 1.7 GHz is described. Special measurement and analytical techniques are necessary owing to the high reflection coefficients and conditional stability of the transistor, as well as the very low noise figures being measured. A single stage amplifier is realised with a noise figure of 1.25 dB and 13.5 dB associated gain at 1.7 GHz.