RF tracking test system design for closed loop testing of Ku-band antenna

Ku band antennae are one of the unique features of GSAT11 spacecraft. As the pointing accuracy of the satellite platform is around 0.1°, improved antenna pointing is achieved using the steerable Deployment Pointing Mechanism (DPM), Radio Frequency (RF) Tracking based measurement system and Attitude and Orbit Control Electronics (AOCE) resident controller. Testing of these subsystems in open and closed loop has been carried out for the first time in zero-g environment. This test has been instrumental in evaluating/validating the closed loop performance of all the subsystems along with the characterization of the RF tracking system and its system response. This paper discusses the design approach and development of RF Tracking Test System and improvements carried out therein to enable smooth testing and lessons learnt. Here, AOCE simulator design has been effected for accelerating the product design cycle and in-parallel carrying out the interface testing along with the algorithmic validation and system characterization.