On-board antenna pattern measurements of a broadcasting satellite

This paper describes methods and results of on-board antenna pattern measurements of BSE (Medium-Scale Broadcasting Satellite for Experimental Purposes). The measurements were carried out by means of satellite attitude offsets about the pitch and roll axes. Measured antenna patterns at both up- and down-link frequencies (14 and 12 GHz) agree with the pre-launch data in the eastwards of the patterns, while they have more gentle gain slopes in the westwards. Further, it is found that antenna pattern deformation occurs along with the change in the antenna temperature. The whole appearance of the deformation seems to be complicated in the center regions of the patterns which almost cover Honshu Island, and the dominant behavior of the deformation appears to be an antenna beam shift of 0.1 to 0.2 deg in the east-west direction.