EM Scattering by a Coated Dielectric Spheroid GEOMETRY OF THE PROBLEM In this chapter we consider the scattering of a linearly polarized plane monochromatic wave by a homogeneous lossy/lossless dielectric spheroid with a confocal lossy/lossless dielectric coating immersed in a homogeneous isotropic medium. It is assumed that the surrounding medium is nonconducting and nonmagnetic | Spheroidal Wave Functions in Electromagnetic Theory Le-Wei Li Xiao-Kang Kang Mook-Seng Leong Copyright 2002 John Wiley Sons Inc. ISBNs 0-471-03170-4 Hardback 0-471-22157-0 Electronic EM Scattering by a Coated Dielectric Spheroid GEOMETRY OF THE PROBLEM In this chapter we consider the scattering of a linearly polarized plane monochromatic wave by a homogeneous lossy lossless dielectric spheroid with a confocal lossy lossless dielectric coating immersed in a homogeneous isotropic medium. It is assumed that the surrounding medium is nonconducting and nonmagnetic. Results are presented only for the prolate spheroids as the results for the oblate cases can be obtained by the transformations i c ic. The media of both the spheroid and the coating layer are both assumed to be linear homogeneous and isotropic with permittivities i and 2 in general complex quantities and nonmagnetic in nature. The permittivity of the surrounding medium is 60 The semiaxial lengths of the spheroidal core are a2 and 621 and those of the spheroid formed by the confocal outer layer are ai and bi. The thickness of the coating is defined as t ai û2- The inner and outer spheroidal surfaces are defined by 2 and 1 respectively Fig. . The relationships governing the parameters c and and the spheroidal dimensions are the same as those in Chapter 4. In addition the following relations hold f1 - 5-la 2 2 Cl . V e0 115 116 EM SCATTERING BY A COATED DIELECTRIC SPHEROID Fig. Scattering geometry of a coated spheroid. INCIDENT TRANSMITTED AND SCATTERED FIELDS 117 e C2 CO- V eO INCIDENT TRANSMITTED AND SCATTERED FIELDS Unlike the case of the perfectly conducting spheroid the existence of fields inside the dielectric spheroid makes the problem more complicated and it is necessary to use the magnetic fields in the boundary conditions. The magnetic field of a propagating wave is related to the electric field via if 4-V x E kZ 5-2 where k is the wave number and Z is the characteristic .
