Phase Calibration of Signal Transmission

Phase calibration device has been developed for frequency standard signal transmission based on TMRT (TianMa Radio Telescope)system. With this device, phase stability can be improved 150 times in comparison with no phase calibration. In this paper, principle of phase calibration is introduced. Its performance is tested. And error sources which degrade phase calibration device's performance including thermal drifts, interference signals and VSWR(voltage standing wave ratio)are analyzed.