An Ultra Low-Noise Schottky Mixer Receiver at 80–120 GHz

Abstract

An ultra low-noise mixer receiver has been developed at the Five College Radio Astronomy Observatory for astronomical observations from 80 to 120 GHz with the 13.7 m diameter millimeter telescope. The cryogenic front end consists of a feed horn, a ring filter and a waveguide mixer followed by a 1.4 GHz FET amplifier. The optimization of the mixer RF-impedance at 100 GHz has yielded single sideband (SSB) receiver noise temperatures of 1 24 K and 588 K at physical temperatures of 18 K and 295 K, respectively.