A New 140 GHz Planar Diode Finline Mixer for Radiometer Applications

Abstract

A new coolable 142 GHz finline mixer using an anti parallel mounted pair of planar air-bridge-type GaAs Schottky barrier diodes is described. Excellent performance data were measured (single sideband noise temperature about 600°K at a case temperaur of 13°K, conversion loss about 6 dB at room temperature). These features are comparable wit the mehanically more complicated whisker contacted mixers, which are traditionally used in atmospheric sounder experiments. The finline mixer has successfully been applied as the core of a receiver frontend for millimetre wave ozone radiometry measurements at 142.175 GHz