In this report, the reflection coefficient of a flanged rectangular waveguide with a metal-backed dielectric slab is rigorously formulated by using the method of the Kobayashi potential (KP). This structure is useful as a model for the precise nondestructive measurement of complex permittivity (dielectric constant and losses) of slab-like samples. The fields in the waveguide and dielectric slab are expanded in terms of the normal mode of the waveguide and the Weber-Schafheitlin discontinuous integrals, respectively. Imposing the continuous properties of the tangential components of the fields on the aperture, we obtain matrix equations for the expansion coefficients of the diffracted wave. The matrix elements consist of double infinite integrals and double infinite series of Bessel functions, which can be calculated efficiently and precisely by applying the asymptotic approximation of the Bessel function and using the Cauchy integral theorem.
展开▼
