Millimetre And Submillimetre Wave Heterodyne Receivers For Atmospheric Sounding And Radioastronomy

Abstract

To prepare the space programs on meteorology and astrophysics, the development of two heterodyne instruments has been supported by the French Space Agency (CNES): a ten channels millimetre wave radiometer for atmospheric sounding; and a balloon-borne observatory (PRONAOS) including a 2 metre telescope associated with a submillimetre heterodyne spectrometer for radioastronomy. This receiver includes a SIS mixer using Nb/AlO/sub x//Nb tunnel junctions operating at 4 K, a 6 GHz IF low-noise cooled preamplifier, a LO quasi-optically injected with a phase locked Gunn oscillator and two cascaded frequency multipliers. Noise temperature as low as 300 K has been obtained; less than 200 K is expected.