Small hemielliptic dielectric lens antenna analysis boundary integral equations vs. GO and PO

The purpose of research is to outline the domain of applicability of the geometrical optics (GO) and physical optics (PO) in the small dielectric lens analysis. As a benchmark solution, we use the Muller's boundary integral equations (IE) discretized with trigonometric Galerkin scheme that has guaranteed and fast convergence. The lens cross-section is chosen typical for practical applications, namely an extended hemiellipse whose eccentricity satisfies the GO focusing condition. The lens flat side dimension varies between 2 and 8 wavelengths in free space, and its material is rexolite (s = 2.53). We consider the 2D case with an E-polarized plane wave incidence and extract comparison characteristics from the near field analysis.