Accuracy of Hybrid Spectral Domain-UTD Method

The analysis of an array of waveguide openings placed at a conformal ground plane and covered with a multilayer radome is approached using the moment method in spectral domain. The main disadvantage of the spectral domain method lies in numerical problems appearing when the structures with large radii are analyzed. We have developed a hybrid spectral domain-UTD method in order to overcome these difficulties and to obtain a fast and accurate analysis method that keeps all advantages of the spectral domain technique. The accuracy of the proposed hybrid method is discussed in the paper. It is shown that the method is not sensitive to the thickness and permittivity of the dielectric layer nearby to the source, which is used in the UTD asymptotic solution