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Solving inhomogeneous problems by integral equation approach relies on the solution of volume integral equations (VIEs) and usually tetrahedral elements in geometrical discretization are required to match arbitrary shapes. However, tetrahedral discretization is expensive since special commercial software is required even for a very simple geometry. In this work, we propose a volume-element-free scheme...
In this paper, the design, modeling and simulation of a partially filled substrate for a rectangular patch antenna is presented. The effect of a piece of a magnetic part on the substrate of the patch antenna is investigated. It is shown that the return-loss, the number and frequency of excited modes and consequently the bandwidth of antenna are a function of the place of this magnetic part in the...
In this paper, we propose an isotropic metamaterial lens (meta-lens) with an operational frequency of 8.5 MHz for imaging applications. The cubic unit cells, composed of inductor-and and capacitor-loaded split rings, are aligned in a periodic three-dimensional dimensional lattice. The meta-lens provides an effective isotropic permeability μeff = −1 at 8.5 MHz. The lens enhances the evanescent fields,...
It is shown that, under some resonance conditions, a microstrip patch antenna can be designed to achieve the highest possible gain when covered with a superstrate at the proper distance in free space. The transmission line analogy and the cavity model are used to deduce the resonance conditions required to achieve the highest gain. The resonance conditions include the condition on spacing between...
In this paper, we present both the theory and design of an anisotropic metamaterial lens for antenna applications. This type of lens requires simple effective medium tensor parameters to achieve highly-directive radiated beams, which differs from more conventional isotropic zero-index metamaterial lenses. Making use of the less dispersive low permittivity and/or permeability band, the lens is promising...
Non-metallic, low-loss double-negative (DNG) metamaterials can be formed by three-dimensional (3D) arrays of two different non-metallic spheres arranged on a simple tetragonal lattice. Such DNG metamaterials have recently been found to provide DNG bandwidths of 10% through 3D arrays of two different dielectric spheres, and of 18% through 3D arrays of dielectric and magnetic spheres. However, a method...
In this paper a simple effective-media analysis (including higher-order multipoles) is used to design a single-resonator, negative-index design based on a metal-core, dielectric-shell (MCDS) unit cell. In addition to comparing the performance of the MCDS design to other core-shell negative-index designs, performance trade-offs resulting from the relative positioning of the electric and magnetic modal...
A three-dimensional (3D) lattice of nanoscale coated spheres is shown to have an isotropic negative index of refraction at optical frequencies. The nanospheres have a core of copper chloride (CuCl) and are coated by a layer of silver. The extended Maxwell Garnett model, relating the Mie resonances of the constituent spheres to the bulk response of the composite, is used for the design. The results...
Three approaches to numerical evaluation of two-dimensional Green's function under TMz polarization are studied for the Veselago Lens of finite and infinite extent. The first approach formulates the Green's function of the infinite lens in terms of Fourier integral which is subsequently evaluated numerically via direct integration along a modified path. The second approach extracts the dominant field...
We develop here a rigorous homogenization approach applied to dense cubic arrays of magnetodielectric spheres, in order to determine their first-principle bulk constitutive parameters. We carefully model their electromagnetic response and assess the validity and limitations of commonly used approximate homogenization models for metamaterials. In particular, we show that, in regimes for which exotic...
This paper presents a new method to improve isolation between two loop antennas with absorber cells exhibiting negative permittivity and permeability at the aimed frequency of 2.45 GHz. The metamaterial (MTM) unit cell was constructed by two open complimentary split ring resonator (OCSRR) and a split ring resonator (SRR) arrangement. The proposed antenna structures were composed of two loop antennas...
Ferrite materials are widely used as chokes to minimize common-mode currents in antenna feeds, in the design of artificial magnetic conductors, and in the filtering of noise at radio frequencies (RF). Miniature inductors, consisting of a thinwire coil around a high-permeability soft ferrite core, find wide application in RF and microwave circuits. An understanding of the high-frequency parasitic and...
In this paper, a μ-Negative metamaterial (MNG) is utilized for mutual coupling reduction between dual-band printed monopole antennas used in Multiple Input Multiple Output (MIMO). A dual-band MNG metamaterial is designed to specifically possess negative effective permeability at the two resonant frequencies where the antennas are operating. MNG is inserted between the two printed monopoles (back to...
A metamaterial slab of Wire-Split Ring Resonators was analyzed focusing on physical aspects. Effective constitutive parameters were extracted vs. number of W-SRR layers in the slab. We have shown that a minimum of 8 layers is required to accurately characterize the bulk metamaterial properties. Losses, spatial dispersion, and mode conversion in the unit cell are also discussed.
This paper presents a novel intelligent metamaterial (I-MTM) design for specific absorption rate (SAR) reduction. The I-MTM can distinguish whether the phantom is close to or far away from itself. In turn it will show different properties. In the SAR reduction mode, the peak SAR value can be reduced by around 56%. In the normal mode, the I-MTM will not affect the performance of an antenna.
This paper presents a new type of thin absorber exhibiting double negative metamaterial (MTM) characteristics. A MTM unit cell was constructed by a multiple split ring resonator (MSRR) and a meander-line arrangement. A MSRR structure exhibits negative permeability and a meander-line structure exhibits negative permittivity. Each unit cell is printed on the two side of a FR-4 substrate (relative dielectric...
A new kind of transmission-line metamaterial unit cell is introduced in this paper. The new unit cell is derived by applying a shear to the existing 2-D, anisotropic, transmission-line metamaterial unit cell. This operation shears one branch of the unit cell while leaving the other untouched. This introduces off-diagonal components in the effective material tensor of the unit cell, giving a full,...
A study is presented on the wave collimation effects of a low-index uniaxial metamaterial slab with the optic axis parallel to the direction of wave propagation. A thin metamaterial lens of such a medium is shown to achieve highly directive radiation. A design example comprised of a metamaterial lens with matched permittivity and permeability placed over a crossed-dipole is presented to demonstrate...
The volume integral equation method is used to analyze electromagnetic scattering from arbitrarily shaped three-dimensional homogeneous objects whose permittivity and permeability differ from those of background medium. We consider three different types of formulations, the DB-formulation with flux densities as unknowns, the EH-formulation with fields as unknowns, and EE- and HH-formulations that...
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