Title :
A Quantum-limited Submillimeter Mixer with an Inhomogeneous Distributed SIS Junction Array
Author :
Shan, WL ; Shi, S.C. ; Sekimoto, Y. ; Noguchi, T.
Author_Institution :
Nat. Astron. Observatories of China, Nanjing
Abstract :
Heterodyne mixing performance of a waveguide SIS mixer with inhomogeneous distributed junction (DJ) array composed of 3 SIS junctions is experimentally investigated at 375-500 GHz. Quantum-limited noise temperature of 3-DJ mixer is demonstrated. Besides its low noise temperature, the mixer conversion gain of 3-DJ mixer is found to be more uniform over RF band than that of a PCTJ (parallel-connected twin junctions) mixer. The FTS (Fourier transform spectrum) response indicates a broad RF bandwidth of the 3-DJ mixer that is limited by the bandwidth of waveguide probe instead of mixer´s tuning circuit.
Keywords :
Fourier transform spectra; circuit noise; submillimetre wave mixers; superconducting arrays; superconductor-insulator-superconductor mixers; Fourier transform spectrum; SIS junction array; distributed junction mixer; frequency 375 GHz to 500 GHz; heterodyne mixing performance; inhomogeneous distributed junction array; quantum-limited submillimeter mixer; waveguide SIS mixer; Bandwidth; Circuit optimization; Current density; Observatories; Optical noise; Optical waveguides; Probes; Radio frequency; Temperature; Waveguide junctions; Distributed junction array; Gain flatness; Noise temperature; SIS mixers; Submillimeter wave;
Conference_Titel :
Microwave and Millimeter Wave Technology, 2007. ICMMT '07. International Conference on
Conference_Location :
Builin
Print_ISBN :
1-4244-1049-5
Electronic_ISBN :
1-4244-1049-5
DOI :
10.1109/ICMMT.2007.381463
