Performance analysis of distorted reflector antennas basing on interval method

The aim of this paper is to analyze pattern distortion of reflector antennas with surface deformation by means of interval arithmetic. Since a reflector surface is susceptible to generate the deformation caused by structural parameter tolerances from the manufacture process or external loads (e.g., gravity, wind and ice) under the operating conditions, a robust analytical expression is introduced to model the effect of surface errors on the radiated performance of the antenna using the interval methods. In the expression, the upper and lower bounds of power pattern intervals are derived as functions of the intervals of surface errors on the basis of distorted surface caused by external loads, where the errors are connected to pattern distortion by the variation of phase terms of the aperture fields. The power pattern intervals are given under the case of different surface errors. The results clearly demonstrate that the interval method have the potential ability of giving a robust performance analysis of distorted reflector antennas.