Design of 345/650 GHz SIS mixers: backup for the LCT dual-color heterodyne receiver

Abstract

The Leighton Chajnantor Telescope (LCT) is an international cooperation project among Caltech, University of Concepcion (UdeC), and Shanghai Normal University (ShNU), which aims to relocate the Caltech Submillimeter Observatory (CSO) telescope from Mauna Kea, Hawaii to the Chajnantor plateau in northern Chile. ShNU has the opportunity to upgrade a 345/650 GHz dual-color SIS receiver, which was made by Caltech, for the LCT. In order to technically support this dual-color receiver, 345/650 GHz SIS mixers were designed and optimized based on the existing superconducting technology in the lab of ShNU. Within the proposed frequency range, both mixers show good sensitivity and gain characteristics. The optimized mixers show a DSB noise temperature of 24K and a conversion gain of 4.2dB at 345GHz, and a DSB noise temperature of 61K and a conversion gain of -2.9dB at 650GHz, respectively. Detailed design and results will be provided.