Analysis of conformal arrays using spectral domain approach — Comparison of different asymptotic extraction methods

The motivation of this paper is to compare different asymptotic approaches when combined with the spectral domain method in the analysis of conformal antennas. The goal is to find the best approach that can significantly reduce the calculation time and at the same time retain analysis accuracy of complex conformal multilayered antenna problems. Four different approaches are compared: extraction based on the large-order form of Bessel and Hankel functions, exponential approximation of Green's functions, homogeneous-space equivalent model, and impedance surface model.