I. H. Tayyar

Influence of the junction of perfectly conducting and impedance parallel plate semi-infinite waveguides to the dominant mode propagation

The Wiener-Hopf technique is used to compute the reflection and transmission coefficients related to the junction of perfectly conducting and impedance parallel plate waveguides in the case where the surface impedances of the upper and lower semi infinite plates are different from each other.

Plane Wave Diffraction by Dielectric Loaded Thick-walled Parallel-plate Impedance Waveguide - Abstract

high frequency diffraction of E z -polarized plane waves by a dielectric loaded thick-walled parallel-plate impedance waveguide is investigated rigorously by using Fourier transform technique in conjunction with the mode-matching method. Relying upon the image bisection principle, the original problem is splitted up into two simpler ones and each individual boundary-value problem is formulated with this mixed method which gives rise to a scalar Wiener-Hopf equation of the second kind. The solution of each Wiener-Hopf equation contains infinitely many constants satisfying an infinite system of linear algebraic equations. A numeric solution of this system is obtained for various values of the dielectric constant, plate impedances plate thickness, and the distance between the plates through which the effect of these parameters on the diffraction phenomenon is studied.

Radiation from Dielectric-Filled Thick-Walled Parallel-Plate Waveguide Junction Loaded with a Dielectric Half-Plane

The radiation of a dielectric-filled thick-walled parallel-plate impedance waveguide junctioned with a thick dielectric half-plane is treated by using the mode-matching method in conjunction with the Wiener–Hopf technique. The hybrid method that we adopt here reduces the related boundary value problem to two scalar modified Wiener–Hopf equations of the second kind. This bypasses the most challenging stage of the classical formulations, which lead to an intractable matrix Wiener–Hopf factorization. The solution involves infinitely many unknown constants satisfying an infinite system of linear algebraic equations susceptible to a numerical treatment. Some computational results illustrating the various values of the dielectric constant, plate impedances, plate thickness, and plate to plate separation distance on the radiation phenomenon are also presented.

Plane Wave Diffraction by Dielectric Loaded Thick-Walled Parallel-Plate Impedance Waveguide

Abstract—The high frequency diffraction of Ez-polarized plane waves by a dielectric loaded thick-walled parallel-plate impedance waveguide is investigated rigorously by using Fourier transform technique in conjunction with the mode-matching method. Relying upon the image bisection principle, the original problem is splitted up into two simpler ones and each individual boundary-value problem is formulated with this mixed method which gives rise to a scalar Wiener-Hopf equation of the second kind. The solution of each Wiener-Hopf equation contains infinitely many constants satisfying an infinite system of linear algebraic equations. A numeric solution of this system is obtained for various values of the dielectric constant, plate impedances plate thickness, and the distance between the plates through which the effect of these parameters on the diffraction phenomenon is studied.

Plane wave scattering by a dielectric loaded slit in a thick impedance screen

The electromagnetic scattering of the plane wave by a slit loaded with dielectric in a thick impedance screen is considered for a rather general case where the surface impedances of the screen planes and vertical sides of the slit have different values. Because of the symmetry of the scattering structure, the image bisection principle is used and the original problem is splitted up into even and odd excitation cases. By introducing the Fourier transform for each case yields a modified Wiener–Hopf equation of the second kind for each excitation. After decoupling these equations by standard transformation, each modified Wiener–Hopf equation is reduced to a pair of coupled Fredholm integral equations of the second kind. The solution of each integral equation involves two sets of infinitely many constants satisfying two infinite systems of linear algebraic equations and Branch-cut integrals which are evaluated approximately. Numerical solutions of these systems are obtained for various values of the parameters such as the surface impedance of the screen, the vertical wall impedance of the slit, the width and the thickness of the slit and the permittivity of the filling material of the slit which permit one to study the effect of these parameters on the diffraction phenomenon. In order to validate the present Wiener–Hopf solution, experimental verification of the dielectric loaded thick metallic slit has been implemented in microwave frequencies with good agreements.

Radiation from a coaxial waveguide formed by a semi-infinite cylindrical outer conductor and an infinite two-part impedance inner cylinder

In the present work, the scattering of a wave radiating inside a waveguide consisting of two coaxial cylinders the inner of which is infinite and has piecewise surface impedance, while the outer cylinder is infinitely thin, semi-infinite and perfect electrical conductor is analyzed using Wiener–Hopf technique. The problem is defined as a Wiener–Hopf equation by applying Fourier transformation to the scattered field and the boundary conditions. The scattered field inside the waveguide is expanded to series in terms of waveguide modes and the solution is obtained using the continuity conditions for the electromagnetic fields and transforming the problem into three sets of infinite algebraic equations containing three sets of infinite constants. In the numerical results section, the effects of the geometrical parameters and the impedances of the waveguide to the radiated field and the reflection coefficient is observed. Obtained results are compared to a previously solved problem.

A Wiener-Hopf analysis of the coaxial waveguide radiator

In the present work, by formulating the radiation from a semi-infinite coaxial waveguide in a different manner that described in [1], we obtained a single modified Wiener-Hopf equation whose solution involves three sets of infinitely many expansion coefficients satisfying three infinite systems of linear algebraic equations. These systems are then solved numerically and some graphical results showing the effects of the radii of the inner and outer cylinder on the radiation phenomenon are presented.