In‐orbit electrical performance evaluation of large satellite‐borne antenna

The satellite-borne antenna is large due to the requirement for a high gain and a multibeam operation. The construction is soft to reduce the weight as much as possible. Therefore, it is difficult to carry out the performance evaluation test on the ground with the configuration in the orbit. This paper presents a method for accurate evaluation of a large antenna in orbit. First, the electrical test results on the ground with a weight deformation made as small as possible is compared with the numerical results based on the measured values of the manufacturing errors so that the evaluation error is obtained. Next, the performance in orbit is obtained by adding the evaluation error to the values computed from the measured fabrication error and assembling error and thermal deformation analysis value. The present procedure was applied to a Ka-band multibeam antenna with an aperture diameter of 3.5 and 2.5 m on board the ETS-VI satellite. It is shown that the evaluation can be done with sufficient accuracy.