A Precise Real-Time Delay Calibration Method for Navigation Satellite Transceiver

This paper presents a high precision method to automatically calibrate the transmission delay of satellite transceivers in real time. The real-time self-calibrated capability is achieved by employing a bidirectional channel into the traditional satellite transceiver. The bidirectional channel can act as a transmitting or receiving path. Three signal loops in the transceiver can be created with a combination of the traditional transmitting channel (Tx), traditional receiving channel (Rx), and the proposed bidirectional channel. Then, the absolute delay of Tx and Rx can be calculated through the total delays in these three loops. The clock error and the distance measurement error between two satellites are calibrated based on the absolute delays, accordingly. A K-band satellite transceiver prototype integrated with a compact bidirectional channel has been developed to verify the proposed method. The measured delay of the cables between the transceiver and the simulator after calibration is temperature-insensitive and close to the true value.