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 L-C transformer as a tuning circuit to its 5 series-connected junctions, which can have 125 - 165 GHz as the operation radio frequency (RF). For intermediate frequency (IF) signal path a high impedance quarter-wavelength line connects the probe to one end of symmetric RF chokes. The double side band (DSB) receiver noise of the mixer was about 40 K over 4 - 6 GHz IF band, whereas we achieved the uncorrected single side band (SSB) noise temperature of about 70 K and better than 10 dB image rejection ratio in 2SB configuration with 8 - 10 GHz IF band. Insert-type receiver cartridges employing the mixers have been under commission for KVN stations.

ABSTRACT
1. 서론
2. KASI KVN-ASIAA SDL 초전도 믹서 설계
    2.1. 도파관 프로브 안테나
    2.2. 접합과 RF 튜닝 회로
    2.3. 설계 믹서의 성능 예측
    2.4. 믹서 칩의 제작
    2.5. 제작 칩의 DC 성능 측정
    2.6. 제작 칩의 RF 성능 측정
3. KVN 129 GHz DUAL-POLARIZATION SSB 수신기
4. 요약 및 토의
참고 문헌

• 이정원(한국천문연구원) | JUNG-WON LEE (Korea Astronomy and Space Science Institute)
• Ming-Jye Wang(Institute of Astronomy and Astrophysics, Academia Sinica)
• Chao-Te Li(Institute of Astronomy and Astrophysics, Academia Sinica)
• Tse-Jun Chen(Institute of Astronomy and Astrophysics, Academia Sinica)
• 김수연(한국천문연구원) | SOOYEON KIM (Korea Astronomy and Space Science Institute)
• Wei-Chun Lu(Institute of Astronomy and Astrophysics, Academia Sinica)
• 강용우(한국천문연구원) | YONG-WOO KANG (Korea Astronomy and Space Science Institute)
• Sheng-Cai Shi(Purple Mountain Observatory, Chinese Academy of Science)
• 한석태(한국천문연구원) | SEOG-TAE HAN (Korea Astronomy and Space Science Institute)