Wideband and low-loss metamaterials for microwave and RF applications: Fast algorithm and antenna design

Abstract

In this chapter, a fast solver, i.e., adaptive integral method (AIM) which is based on hybrid volume-surface integral equation, is utilized in the numerical simulation of electromagnetic scattering from composite left-handed materials (LHM) such as split-ring resonators (SRR) with rods/wires. The volume electric field integral equation (EFIE) is applied to the dielectric region of this LHM, and the surface EFIE is applied on the conducting surface. The method of moments (MoM) is used to discretize the integral equation into a matrix solution and AIM is employed to reduce the memory requirement and CPU time for the matrix solution. Numerical results and computational complexity analysis have shown that the AIM solver can significantly reduce the computational cost while maintaining a good accuracy. Inspired by the periodicity of SRR, the ASED-AIM, a new adaptive integral approach based on accurate sub-entire-domain method, has been proposed to solve the electromagnetic scattering by large-scale finite periodic arrays, especially the LHM structures like SRR. Several results are shown to demonstrate the efficiency of the method in solving periodic structures. Additionally, further computational time saving scheme for calculating the near-zone interaction matrix has been proposed. Both 2-D and 3-D periodic structures can be solved by this fast solver with impressive efficiency and accuracy. In the last section of this chapter, a novel rectangular patch antenna was specifically designed using planar-patterned LHM concepts. This new antenna has demonstrated to have left-handed characteristics. It is shown to have great impact on the antenna performance enhancement in terms of the bandwidth significantly broadened and also in terms of high efficiency, low loss, and low VSWR. A good agreement is achieved between the simulation and measured results. This new antenna designed has strong radiation in the horizontal direction within the entire working band, which is desirable for some special applications. © Springer Science+Business Media, LLC 2010.