Analysis Of Reflector Antenna Structure And Performance Using Non-probabilistic Interval Method

In reality, the distortion of antenna surface and the feed position will be uncertaindue to the uncertainties of the structure parameters and applied loads. Thus theelectrical performance will vary in an interval. In this paper, intervals are used toexpress the uncertain parameters of reflector antenna. The influences of the uncertainerrors on antenna structure and electrical performance are analyzed based onnon-probabilistic interval method.The paper first discusses the effect of the uncertain parameters on the surfacedistortion of reflector antenna. The procedure of interval perturbation solution and thecriterion of interval truncation are given. By the interval matrix perturbation method,the perturbation solution of the interval finite element equation is obtained. Due to theinterval extension contained in the perturbation solution, the obtained results aretruncated with the interval truncation method to get more precise surface nodaldisplacements of reflector antenna. The surface distortion intervals are obtained byinterpolating.The effect of the uncertain errors of reflector antenna on the electricalperformance is also analyzed. The relationship between the surface distortion errors aswell as the position errors of the feed phase center and the aperture electromagneticfield is deduced. An interval numerical model, which reflects the effect of theuncertain errors of reflector antenna on the far field pattern, is established. Thetrigonometric function is used to express the complex exponential and its numericalresults are solved so as to calculate interval complex exponential. Meanwhile, aconcrete formula of calculating the lower and upper bounds of the power patternfunction is derived. Then the interval numerical model is applied to reflector antennasgiven. The effect of the uncertain errors on the power pattern is discussed and areasonable result is obtained. The indexes of electrical performance achieved areillustrated by interval, which can provide theoretical support and reference for theantenna designers.