In this paper novel reflectarray antenna elements are proposed using aperture-coupled dielectric resonator antenna structures. Using these new structures, wide phase range and wide frequency bandwidth (up to 28.5%) with parallel and linear phase curves are obtained. In each case, an array consisting of 289 elements was simulated using the finite integration technique (FIT). The arrays exhibit 3...

In this paper a new method for solving (non-linear) ordinary differential equations is proposed. The method is based on finite elements (collocation method) as well as on genetic algorithms. The method seems to have some advantages in comparison with the typical sequential (one – step and multi – step) methods. Key-Words: Ordinary Differential Equations, Finite Elements, Genetic Algorithms, Evo...

This study is concerned with the formulation of three dimensional mapped infinite elements with 1/r and 1/ decay types. These infinite elements are coupled with conventional finite elements and their application to some problems of soil structure interaction are discussed. The effeciency of the coupled finite-infinite elements formulation with respect to computational effort, data preparation a...

In this paper we consider the evolving surface finite element method for the advection and diffusion of a conserved scalar quantity on a moving surface. In an earlier paper using a suitable variational formulation in time dependent Sobolev space we proposed and analysed a finite element method using surface finite elements on evolving triangulated surfaces. An optimal order H1-error bound was p...

A simple finite element method for the Reissner–Mindlin plate model in the primitive variables is presented and analyzed. The method uses nonconforming linear finite elements for the transverse displacement and conforming linear finite elements enriched by bubbles for the rotation, with the computation of the element stiffness matrix modified by the inclusion of a simple elementwise averaging. ...

3D Hybrid Finite Element Finite Difference Time Domain (FE/FDTD) Method is developed and applied to the numerical modeling of antennas. The antenna geometry is modeled using tetrahedral finite element mesh. Pyramidal elements are introduced in the transition from unstructured tetrahedral elements to structured hexahedral elements. The finite element formulation incorporates the excitation of an...