Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy XI
SIS mixers study on Heterodyne Array Receiver Program (HARP) at JCMT
Kuan‐Yu Liu, Ming-Jye Wang, Edward Tong, Per Friberg, G. A. Fuller, Tse-Jun Chen, Yen-Pin Chang, Wei-Chun Lu, Dan Bintley, Ming‐Tang Chen, Chih-Chiang Han, Sheng-Feng Yen, Jessica T. Dempsey, Shaoliang Li, Craig A. Walther, Vernon DeMattos, Jamie L. Cookson, Graham Bell, Xue-Jian Jiang, Harriet Parson, Izumi Mizuno, Taishi Nammoto, Weiye Zhong
Abstract
We have fabricated new superconductor-insulator-superconductor (SIS) mixers chips for the 16-element Heterodyne Array Receiver Program (HARP) instrument on the James Clerk Maxwell Telescope (JCMT). The original spare mixer chips were limited and not performed as well as the used ones in HARP. The ability to manufacture new mixer chips would therefore be important for the repair and upgrade of HARP. Our immediate goal is to replace the current nonfunctional mixers in HARP with new chips. We modified the designs of waveguide probe and the matching circuit of the SIS mixer chip. The newly designed chips were fabricated with a quality factor (Rsg/Rn) over 10. The double-sideband (DSB) receiver noise temperature (Trx) is lower than 80K at frequencies between 325 GHz and 375 GHz, which is comparable to the best of the original devices. Three of the sixteen mixers have been replaced and they work very well.