HIGH-FREQUENCY SCATTERING OF A WHISPERING-GALLERY MODE BY A CYLINDRICALLY CURVED SURFACE WITH 2ND-ORDER GENERALIZED IMPEDANCE BOUNDARY-CONDITIONS

A high-frequency solution is derived for the diffraction of electromag netic waves by a cylindrically curved metallic sheet whose concave and convex faces are coated by dielectric layers of the same physical pro perties and thicknesses. After simulating the effects of the grounded dielectric layer by second-order generalized impedance boundary condit ions, a canonical problem is formulated in an infinitely extended angu lar space from which explicit asymptotic expressions for the diffracti on coefficients are obtained through the asymptotic solution of a Hilb ert problem.