A fiber-optic reference signal transmission system, which transmits the 1.4 GHz reference signal from H-maser to receiver cabin in radio telescopes, was adopted for compensating the phase changes due to temperature variation and antenna movement. At the first experiment, the remote signal’s phase changed more than 15 degrees at 1.4 GHz. We found unstable components in sub-system experiments and replaced them. The main cause of unstable phase stability was the unaligned polarization axis between Laser Diode and Mach-Zehnder Modulator (MZM). The improved system stability showed 1 × 10-16 allan standard deviation at 1,000 sec integration time with the antenna fixed. When the antenna moves in the azimuth axis, the 1.4 GHz remote signal showed the phase change smaller than 0.2 degrees.

ABSTRACT
1. 서론
2. 시스템 동작원리 및 초기 성능 측정
    2.1. 시스템 동작원리
    2.2. 초기 성능 측정
3. 시스템 개선
    3.1. PMF(Polarization Maintaining Fiber) 영향
    3.2. 안테나 움직임의 영향 개선
    3.3. 시스템 안정화
4. 결론
참고 문헌

• 제도흥(한국천문연구원) | DO-HEUNG JE (Korea Astronomy and Space Science Institute)
• 이원규(한국표준과학연구원) | WON-KYU LEE (Korea Research Institute of Standards and Science)
• 김수연(고려대학교) | SOO-YEON KIM (Korea University)
• 정문희(한국천문연구원) | MOON-HEE CHUNG
• 송민규(한국천문연구원) | MIN-KYU SONG (Korea Astronomy and Space Science Institute)
• 정태현(한국천문연구원) | TAEHYUN JUNG (Korea Astronomy and Space Science Institute)
• 변도영(한국천문연구원) | DO-YOUNG BYUN (Korea Astronomy and Space Science Institute)
• 김승래(한국천문연구원) | SEUNG-RAE KIM (Korea Astronomy and Space Science Institute)
• 손봉원(한국천문연구원) | BONG-WON SOHN (Korea Astronomy and Space Science Institute)
• 위석오(한국천문연구원) | SEOG-OH WI (Korea Astronomy and Space Science Institute)
• 한석태(한국천문연구원) | SEOG-TAE HAN (Korea Astronomy and Space Science Institute)
• 강용우(한국천문연구원) | YONG-WOO KANG (Korea Astronomy and Space Science Institute)