Design of a new calibration device for Two-Way Satellite Time and Frequency Transfer station

The Calibration Device is used to measure the time delay difference between the transmission and receiving paths inside Two-Way Satellite Time and Frequency Transfer (TWSTFT) earth station, it can improve the time comparison precision. A new calibration device for TWSTFT has been developed recently at Beijing Institute of Radio Metrology and Measurement (BIRMM). The signal paths inside calibration device is bidirectional which allow both the transmission and receiving signal passed, so the delay difference of the transmission and receiving inside calibration device almost be zero. The calibration device works on Ku-band. To evaluate the performance of the BIRMM calibration device, a local TWSTFT experiments was done with SATRE modem. The measurement results show that the time delay difference was quite small instability with standard deviation (1 σ) equal to 0.17ns.