Performance of a twin-slot antenna coupled NbN hot electron bolometer mixer at 2.5 THz
Wen Zhang, J. R. Gao, Merlijn Hajenius, Wei Miao, P. Khosropanah, T. M. Klapwijk, Sheng-Cai Shi, And Darren Hayton
Abstract
We demonstrate a quasi-optical NbN hot electronbolometer (HEB) mixer using a twin-slot antenna on a Si lens tocouple terahertz radiation. The mixer shows a receiver noisetemperature of 1150 K at 2.5 THz, which is expected based on atemperature of 1150 K at 2.5 THz, which is expected based on amodel that includes quantum noise. The measured direct response.is understood by taking into account the main beam efficiency andthe parasitic reactance due to the geometric change betweenbolometer and transmission line. The measured beam of the mixeris nearly collimated and has a Gaussian beam efficiency of 90 %with side-lobes below -16 dB.