Title :
Comparison of the performance of a 0.5-THz Nb and NbN superconducting SIS mixer
Author :
Li, Jing ; Takeda, Masanori ; Wang, Zhen ; Shi, Sheng-Cai
Author_Institution :
Purple Mountain Obs., Chinese Acad. of Sci., Nanjing, China
Abstract :
In THz regime, NbN Superconductor - Insulator - Superconductor (SIS) mixers are potentially applicable to astronomy and atmospheric research. We have developed a 0.5-THz waveguide SIS mixer incorporating twin NbN/AlN/NbN junctions and NbN/MgO/NbN tuning circuit. In this paper, we compare it with a 0.5-THz Nb SIS mixer, which has been successfully used on POST telescope. The design and fabrication parameters of the two mixers are introduced, and the noise temperatures are measured. In addition, the direct detection performance is analyzed, such as the shot noise, the current responsivity and the noise equivalent power. The detailed results are presented.
Keywords :
aluminium compounds; circuit tuning; magnesium compounds; niobium; niobium compounds; shot noise; submillimetre wave mixers; superconductor-insulator-superconductor mixers; telescopes; terahertz wave devices; waveguides; Nb; NbN-AlN-NbN; NbN-MgO-NbN; POST telescope; current responsivity; frequency 0.5 THz; noise equivalent power; noise temperatures; shot noise; superconductor-insulator -superconductor mixers; tuning circuit; twin junctions; waveguide SIS mixer; Astronomy; Atmospheric waves; Circuit noise; Insulation; Josephson junctions; Niobium; Superconducting device noise; Superconducting devices; Temperature measurement; Waveguide junctions; Nb; NbN; SIS mixer; THz; direct detect; heterodyne;
Conference_Titel :
Microwave Conference, 2009. APMC 2009. Asia Pacific
Conference_Location :
Singapore
Print_ISBN :
978-1-4244-2801-4
Electronic_ISBN :
978-1-4244-2802-1
DOI :
10.1109/APMC.2009.5385402
