A planar quasi-optical SIS receiver |
| |
Authors: | Stimson P.A. Dengler R.J. LeDuc H.G. Cypher S.R. Siegel P.H. |
| |
Affiliation: | Jet Propulsion Lab., California Inst. of Technol., Pasadena, CA; |
| |
Abstract: | A planar, quasi-optical SIS (superconductor-insulator-superconductor) receiver operating at 230 GHz is described. The receiver consists of a 2×5 array of half-wave dipole antennas with niobium-aluminum oxide-niobium SIS junctions on a quartz dielectric-filled parabola. The 1.4-GHz intermediate frequency is coupled from the mixer via coplanar strip transmission lines and 4:1 balun transformers. The receiver is operated at 4.2 K in a liquid helium immersion cryostat. Accurate measurements of the performance of single untuned array receiver elements are reported. A mixer noise temperature of 89 K DSB (double sideband), receiver noise temperature of 156 K DSB and conversion loss of 8 dB into a matched load have been obtained. This mixer noise temperature is approximately a factor of two larger than that of current state of the art waveguide mixers using untuned single junctions a the same frequency |
| |
Keywords: | |
|
|