Title :
Local oscillator noise suppression by a balanced SIS mixer in the 0.9 THz band
Author :
Kojima, T. ; Fujii, Yuka ; Asayama, Shinobu ; Uzawa, Y.
Author_Institution :
Nat. Astron. Obs. of Japan, Mitaka, Japan
Abstract :
Local oscillator (LO) sideband noise suppression by a balanced superconductor-insulator-superconductor (SIS) mixer was investigated in the 0.9 THz band. An LO signal in the 0.9 THz band was generated by using fixed tuned x9 (x3 by x3) multipliers located in the cryostat 4-K stage. Despite the huge LO noise of about 1000 K of a YIG driven LO, the measured receiver noise temperature for YIG and Gunn driven LOs was similar because of the high LO sideband noise rejection ratio (LNR) of the balanced mixer.
Keywords :
interference suppression; multiplying circuits; submillimetre wave oscillators; superconducting microwave devices; superconductor-insulator-superconductor mixers; Gunn driven LO; LNR; LO sideband noise suppression; YIG driven LO; balanced SIS mixer; balanced superconductor-insulator-superconductor mixer; cryostat stage; fixed tuned multipliers; frequency 0.9 THz; high LO sideband noise rejection ratio; local oscillator noise suppression; receiver noise temperature; temperature 4 K; Amplitude modulation; Couplers; Mixers; Noise; Radio frequency; Receivers; Temperature measurement;
Conference_Titel :
Infrared, Millimeter, and Terahertz Waves (IRMMW-THz), 2013 38th International Conference on
Conference_Location :
Mainz
DOI :
10.1109/IRMMW-THz.2013.6665822
