Title :
Characterization of a quasi-optical NbN superconducting HEB mixer at 300 GHz
Author :
Miao, W. ; Jiang, L. ; Luo, Y. ; Lin, Z.H. ; Yao, Q.J. ; Shi, S.C.
Author_Institution :
Purple Mountain Obs., CAS, Nanjing, China
Abstract :
In this paper, we present the performance of a quasi-optical NbN superconducting HEB (hot-electron bolometer) mixer cryogenically cooled by a 4-K close-cycled refrigerator. The variation of resistance of the NbN HEB mixer with respect to temperature is examined at first. Its receiver noise temperature and conversion gain are measured at different dc bias voltages and LO pumping levels. The lowest receiver noise temperature is 1400 K (with no corrections), and reduced to about 358 K after eliminating the quasi-optical losses. The stability of IF output power of this HEB mixer is also discussed.
Keywords :
bolometers; circuit stability; cryogenic electronics; hot carriers; millimetre wave detectors; millimetre wave mixers; niobium compounds; submillimetre wave detectors; submillimetre wave mixers; superconducting mixers; superconducting photodetectors; 1400 K; 300 GHz; 4 K; IF output power stability; NbN; conversion gain; cryogenic cooling; hot-electron bolometer mixer; quasi-optical losses; quasi-optical superconducting HEB mixer; receiver noise temperature; Bolometers; Electrical resistance measurement; Gain measurement; Noise level; Noise measurement; Noise reduction; Refrigeration; Superconducting device noise; Temperature; Voltage; 4-K close-cycled refrigerator; NbN HEB mixer; conversion gain; noise temperature;
Conference_Titel :
Microwave Conference Proceedings, 2005. APMC 2005. Asia-Pacific Conference Proceedings
Print_ISBN :
0-7803-9433-X
DOI :
10.1109/APMC.2005.1606816
