Study on Converter Path Delay Vary with Temperature in TWSTFT

Up and Down-converters are the very important equipments in the Two Way Satellite Time and Frequency Transfer (TWSTFT). Up-converter is the transmit equipment while the Down-converter belong to receive facility. They take the role of changing from middle frequency signal (70MHz) to high frequency (up link is 14GHz, down link is 12GHz). In order to improve the time transfer precise, we measure and calculate the path delay of converter vary with the temperature. In this text, we replaced the satellite transponder by the Loop translator. We controlled the temperature around of the up and down-converter and did a TW loop experiment which transmit and receive by oneself. The temperature recorder wrote down the temperature value while the time interval counter recorded the path delay. Analyzing the relation between the path delay and temperature value, we found the following result: from 6 to 13 centigrade degree, the time delay is stable. That means during this temperature period, the time delay do not float obviously. So to reduce the effects by temperature, the best choice is keeping the temperature condition in 6 to 13 centigrade degree range. In the text, we compare the performance of time transfer with 6 to 13 centigrade degree and with other terms temperature range.