Phase error effects on gain and sidelobe level of a space-fed array

A space-fed array is two back-to-back arrays that are connected together by a transmission line. The feed, which is located at the focal point, illuminates one side of the array and the energy which is intercepted by each of the elements is, in turn, transmitted to a corresponding element of the other array via a transmission line. This arrangement acting as a lens focuses the energy radiated into space. The effects of errors on the main beam gain and the average sidelobe level are treated. Two types of errors are considered: 1) random errors which are usually associated with manufacturing tolerance of the array, and 2) axial errors which tend to be somewhat compensating between the two sides of the array. The axial errors are usually associated with the effects of thermal gradients and structural motion that could be encountered in a large antenna system.