Noise temperature and IF bandwidth of a 1.4 THz superconducting HEB mixer

In this paper, the noise temperature and IF bandwidth of a 1.4 THz twin-slot antenna coupled NbN superconducting HEB mixer are thoroughly investigated. The RF noise and conversion gain of the HEB mixer have been measured and analyzed. An anti-reflection coating has been applied on the elliptical lens to reduce the RF noise, the measured lowest noise temperature (450 K) achieves state-of-the-art sensitivity at 1.3 THz. The measured IF noise bandwidth is about 3 GHz, which is sufficiently large for some astronomical applications.