A low-noise 810 GHz heterodyne receiver for molecular-line astronomy

A low-noise 810 GHz heterodyne receiver for astronomy is described. The mixer consists of a NbTiN SIS junction, mounted in a half-height rectangular waveguide mixer block. The receiver has been successfully tested on the UK Infrared Telescope, Hawaii, with a DSB system noise temperature of 280 K at 808 GHz. Observations of several astronomical sources have verified the sensitivity of the instrument.