124-142 GHz Dual-Polarization Superconducting Mixer Receiver for Korean VLBI Network

  • Lee, Jung-Won (Korea Astronomy and Space Science Institute) ;
  • Wang, Ming-Jye (Academia Sinica Institute of Astronomy and Astrophysics) ;
  • Kim, Soo-Yeon (Korea Astronomy and Space Science Institute) ;
  • Li, Chao-Te (Academia Sinica Institute of Astronomy and Astrophysics) ;
  • Chen, Tse-Jun (Academia Sinica Institute of Astronomy and Astrophysics) ;
  • Kang, Yong-Woo (Korea Astronomy and Space Science Institute) ;
  • Lu, Wei-Chun (Academia Sinica Institute of Astronomy and Astrophysics) ;
  • Shi, Sheng-Cai (Purple Mountain Observatory, Chinese Academy of Science) ;
  • Han, Seog-Tae (Korea Astronomy and Space Science Institute)
  • Published : 2012.04.03

Abstract

We have developed superconducting mixer receivers for 129 GHz VLBI observation in Korean VLBI Network(KVN). The developed mixer has a radial waveguide probe with simple transmission line LC transformer as a tuning circuit to its 5 series-connected junctions, which can have 125-165 GHz as operation RF frequency. For IF signal path a high impedance quarter-wavelength line connects the probe to one end of symmetric RF chokes. DSB receiver noise of the mixer was about 40 K over 4-6 GHz IF band whereas we achieved about uncorrected SSB noise temperature of 70 K and better than 10 dB IRR in 2SB configuration with 8-10 GHz IF band. Insert-type receiver cartridges using the mixers have been assembled for all three KVN stations. On-site performance summary in commissioning phase is presented.

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