T. Ege

FSS Comprised of One - and Two - Turn Square Spiral Shaped Conductors on Dielectric Slab

The scattering of electromagnetic waves from a Frequency Selective Surfaces (FSSs) composed of a new one- and two-turn square spiral shaped periodic structures are investigated by using modal expansion method for a linearly polarized transverse electric (TE) and transverse magnetic (TM) incident waves. The Moment Method (MM) of Galerkin type is employed by expressing the current induced on the metallic surfaces in terms of Piecewise Sinusoidal (PWS) basis functions to determine the FSS structure reflection and transmission coefficients.

On the Convergence Acceleration of Slowly Convergent Sums Involving Oscillating Terms

In this paper, an acceleration technique based on a Kummer’s transformation method is developed for some slowly convergent series. The original series is decomposed into two parts; one part being rapidly convergent and the other part being slowly convergent. Then the series in the slowly convergent part is expressed as integrals of some auxiliary functions and subsequently they are written in terms of polynomials whose coefficients are given by the zeta functions. The given method is computationally oriented and does not involve much analytic effort. A numerical example is provided to illustrate the usage and the efficiency of the method.

Effect of curvature on the attenuation constant in hollow circular waveguides

The attenuation and transmission characteristics of curved hollow circular metallic or dielectric waveguides are being analyzed on the assumption that the radius of the curvature is sufficiently greater than that of the waveguide. The electric and magnetic field components are obtained easily using the expansion of the scalar wave function and Maxwells equations in toroidal coordinate system. Results obtained for metallic and dielectric waveguides show excellent agreement with those obtained in the literature.<<ETX>>