International Symposium on Antennas and Propagation
Asymptotic Analysis of Scattered Field by the Edge of a Cylindrically Curved Conducting Open Surface
Keiji Goto, Toru Kawano, Toyohiko Ishihara,
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When the high-frequency (HF) electromagnetic wave is incident on the edge of a cylindrically curved conducting surface, the scattered field in the concave portion of the curved surface may be analyzed asymptotically by dividing the observation region into two subregions. One of which is the subregion called the boundary layer which corresponds to the region bounded by the curved conducting surface and the modal caustic of the whispering gallery (WG) mode . The other is the interior region surrounded by the boundary layer. The scattered field in the interior region may be analyzed by using only the geometrical ray (GO). In this paper, we shall first study the analysis method for the scattered field in the boundary layer when the HF electromagnetic wave is incident on one of the edges of a curved surface. We shall derive the hybrid GO and modal ray solution for the scattered field in the boundary layer. Then, by extending the above hybrid solution, we shall derive the asymptotic solution for the scattered field by the curved open surface. We will confirm the validity of the asymptotic representation proposed in the present study by comparing with the reference solution obtained from the method of moment (MoM).