Performance of twin-slot antenna coupled NbN hot electron bolometer mixers at frequencies ranging from 1.4 to 4.7 THz

摘要

For astronomical observations at frequencies beyond 1 THz, heterodyne detection with NbN hot electron bolometer (HEB) mixers is preferable. In this research we improve the coupling of incoming radiation to the HEB using twin-slot antennas. Our experiments focus on the performance of our antenna designs with frequencies at interesting molecular emission lines corresponding to 1.4, 1.9, 2.7, and 4.7 THz. We make detailed analysis of the performance of the 1.4 THz HEB and demonstrate an excellent measured receiver noise temperature T_(rec) of 480 K with a noise bandwidth of 3 GHz.