Effect of random surface errors on radiation characteristics of the side-fed offset Cassegrain antenna

In this paper 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 ra-diation characteristics of the antenna is introduced.Here,the random surface error is defined as the error of the stan-dard reflector in its normal direction and the errors in a small zone of the reflector are considered as equal.We also assume that the phase error on the aperture led by the ran-dom surface error obeys a Gaussian distribution with zero mean,under which the expression of the average power pattern is deduced.Finally,the data related to the radiation characteristics of the antenna are calculated and the corre-sponding curves are presented.The obtained results can be used for the user to determine the manufacturing accuracy of the reflector of the SFOC antennas.