WIDE-BAND LOW-NOISE MM-WAVE SIS MIXERS WITH A SINGLE TUNING ELEMENT

Several SIS quasiparticle mixers have been designed and tested for the frequency range from 80 to 115 GHz. The sliding backshort is the only adjustable rf tuning element. The rf filter reactance is used as a fixed rf matching element. A mixer which uses a single 2 multiplied by 2 mu m**2 Pb-alloy junction in a quarter-height waveguide mount has a coupled conversion gain of G//M(DSB) equals 2. 6 plus or minus 0. 5 db with an associated noise temperature of T//M(DSB) equals 16. 4 plus or minus 1. 8 K at the best DSB operation point. The receiver noise temperature T//R(DSB) is 27. 5 plus or minus 0. 8 K for the mixer test apparatus.