A Low Noise Receiver At 22 Ghz For The Radioastron Satellite

Abstract

The Radioastron space research satellite, expected to be launched in 1994, will have on board four sensitive, two-channel radiometers. In this paper, the design and testing of the 22 GHz receiver is described. The most important properties of the receiver are sensitivity, phase stability and gain stability. To reach maximum sensitivity, a modern space qualified low noise HEMT amplifier (LNA) has been designed. The measured LNA noise temperature is 101 K. For maximum phase and amplitude