Savas Uckun

Multilayer System of Lorentz/Drude Type Metamaterials with Dielectric Slabs and its Application to Electromagnetic Filters

MULTILAYER SYSTEM OF LORENTZ/DRUDE TYPEMETAMATERIALS WITH DIELECTRIC SLABS AND ITSAPPLICATION TO ELECTROMAGNETIC FILTERSC. SabahPhysikalisches InstituteJohann Wolfgang Goethe UniversityMax-von-Laue-Strasse 1, D-60438, Frankfurt am Main, GermanyS. UckunElectrical and Electronics Engineering DepartmentUniversity of GaziantepGaziantep 27310, TurkeyAbstract—In this work, frequency behavior of the multilayerstructure comprised of double-negative (DNG) and dielectric slabs ispresented in detail. The multilayer structure consists of

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.

Bloch impedance analysis for a left handed transmission line

In this study, the dispersion relation and the frequency dependence of Bloch impedance in a left handed transmission line (LH-TL) is carried out using the F-matrix formulation and Bloch-Floquet theorem. The artificial LH-TL formed by periodic lumped elements is described and the F-matrix, dispersion relation and the Bloch impedance are formulated according to this description. Numerical results for lossless and lossy LH-TL are presented and discussed.

Frequency Response of Multilayer Media Comprised of Double-Negative and Double-Positive Slabs

We present the interactions of the electromagnetic waves with multilayer media formed by double-negative and double-positive slabs to find the frequency response of the structure. The double-negative slabs are analytically realized by using the frequency dispersive cold plasma medium. Numerical examples are performed using an in-house developed simulation programme code. The variation of the reflectance and the transmittance with the emphasis on the plasma frequencies is observed in these examples.

High-pass filter characteristic of Bloch impedance in a left-handed transmission line

This paper shows the high-pass filter characteristic of a left-handed transmission line structure modeled through the Bloch impedance approach using ABCD matrix formulation and Bloch-Floquet theorem. The artificial left-handed transmission line model is carried out and then the Bloch impedance is calculated. Finally, numerical results for lossless left-handed transmission line are presented and discussed.

Scattering Characteristics of Stratified Double Negative Stacks Using the Frequency Dispersive Cold Plasma Medium

We present the wave propagation through stratified double negative stacks to illustrate the scattering characteristics of their structure. The double negative stacks are modeled by using the hypothetical non-dispersive and the frequency dispersive cold plasma media. The stacks are embedded between two double positive media and the incident electric field is assumed a plane electromagnetic wave with any arbitrary polarization. By imposing the boundary conditions, the relations between the fields inside and outside the stacks can be written in a matrix form. Using this transfer matrix, the incident, reflected, and transmitted powers are derived. The variations of the powers for the stratified double negative stacks using the frequency dispersive cold plasma medium have not been investigated yet, in detail. Thus, their characteristics for the perpendicular polarization is computed and presented in numerical results with the emphasis on the plasma frequencies. It is seen from the numerical results that the stratified double negative stacks can be used as electromagnetic filters at some frequency bands.

A vector diagram of Maxwell's equations for chiral media

A vector diagram of Maxwells time-harmonic equations in homogeneous isotropic media is proposed and derived to include chiral media. This diagram may be used to obtain a number of common relationships between fields, potentials and sources by equating appropriate components of the vectors in it. The construction of the diagram is based on the formal similarity between many theorems of vector calculus and those of vector algebra. The construction of the diagrams for two different gauge choices, Lorentz and Coulomb gauges, is explained in detail and some of the equations which can possibly be derived from one of the diagrams is presented.

Admittance determination for cylindrical soft and hard surface chirowaveguides for mode transformation

The generalized dyadic admittance resulting from the transverse fields in slightly chiral soft and hard surface waveguides is presented. The derived admittance is useful in describing the mode transforming effect of the waveguide. In the analysis of the admittance equations, it is observed that the length of the waveguide is of critical importance.