100 K uncooled GaAs M.E.S.F.E.T. amplifier as paramp replacement

The paper considers the design of a low noise uncooled GaAs MESFET amplifier intended to replace narrowband uncooled parametric amplifiers operating at 1.7 GHz at earth receiving satellite stations. Attention is given to special measurement and analytical techniques necessary due 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 was realized with a noise figure of 1.25 dB and associated gain of 13.5 dB at 1.7 GHz, a performance comparable to that achieved by commercial uncooled paramps. However, no paramp can match the performance of the MESFET over the 1.6-1.8 GHz bandwidth: a maximum noise figure of 1.6 dB with an associated gain of 13.5 plus or minus 0.2 dB.