Abstract: The average power pattern of the Side-Fed Offset Cassegrain (SFOC) dual reflector antenna is analyzed, and the effect of the random surface error on radiation characteristics of the antenna is addressed. Here, the random surface error is defined as the error of the standard reflector in its normal direction and the error in a small zone of the reflector is considered as the same. We also assume that the phase error on the aperture led by the random surface error obeys the Gaussian distribution with a zero mean, under which the expression for the average power pattern is deduced. Finally, the data related to the radiation characteristics of the antenna are calculated and the corresponding curves are presented. The obtained results can be used to determine the manufacturing accuracy of the antenna’s reflectors.

Key words: reflector antenna, average power pattern, random surface error, Gaussian distribution