320-420GHz Low-Noise Heterodyne Receiver Modules for the Submillimeter Array of Taiwan

The development on the 320-420 GHz SIS heterodyne receiver modules for the Submillimeter Array (SMA) of Taiwan is presented in this paper. This newly developed receiver band, along with the existing 250-354 GHz SIS heterodyne receivers, provides dual-polarization observation capability over 320-354 GHz, which cover important C03-2 and HCN5-4 molecular emission lines from the celestial objects. The receiver configuration, including the optics, local oscillator and the receiver cryogenic section, will be described. The measured receiver DSB noise temperature is around 70-140K. The quasi- optical beam characteristics of the receiver module also measured at selected RF frequency to ensure good optics alignment.