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In this study, an electrically small, monopole slot antenna based on near-field resonant parasitic (NFRP) elements composed of metamaterial inspired capacitively loaded loop (CLL) elements is designed and analyzed via a commercial full wave electromagnetic solver. The proposed antenna has an operational frequency of 2.4 GHz and it satisfies the limits of an electrical small antenna (ESA) having a...
An electronically tunable polarization rotator based on tensor metasurfaces operating at 10 GHz is reported. The metasurface design allows the polarization tilt angle of a linearly polarized wave to be arbitrarily controlled through a simple biasing mechanism. In addition to allowing global polarization control, the design also allows global phase control.
In this paper, the feasibility of the implementation of microwave components in groove gap waveguide technology by glide-symmetry holey EBG is discussed. Using this technology, microwave components and antennas which were previously designed for hollow metallic waveguides can be manufactured in a cost-effective way at high frequencies. To show the viability of the proposed solution a phase shifter...
A new metamaterial based subwavelength resonators configuration for X-band hollow waveguides is proposed and its application as a filter and crack detection sensor is discussed. The structure is composed of a complementary rectangular split ring resonator embedding a T-type resonator. The filter has a 0.9 GHz bandwidth at 9.11 GHz resonance frequency. The comparison between a perfect surface and a...
In this work, we present a new formula for evaluating the half-power beamwidth (HPBW) of 1-D leaky-wave antennas (1-D LWAs). With respect to Oliner's formula, whose validity is restricted to certain hypothesis on the beam size and the pointing angle, our analysis is quite general, being accurate even when radiation points near endfire, where current formulas notably diverge. Even more interestingly,...
This paper presents the design, simulation, manufacturing and testing of a simple invisibility cloak based on a frequency selective surface (FSS). The work is focused on cloaking an electrically thin dielectric cylinder with an easy to manufacture FSS made of copper strips glued to the cylinder surface. In contrast to many papers in the literature, the full procedure from formulation to measurement...
Full-wave numerical approaches for the analysis of leaky modes propagating in Electromagnetic-Bandgap (EBG) waveguides composed by multilayered arrays of two-dimensional (2D) cylindrical inclusions have been proposed. A first method based on the lattice sums technique for periodic structures with inclusions of circular section has been suitably adapted to the analysis of modes with complex propagation...
In this paper, the stop-band of two different holey glide-symmetric EBG lattices is studied. The results show that glide-symmetric EBG structures have potential to achieve wide stop-bands by polygonal lattices. Potential application of the proposed EBG structure in gap-waveguide technology is discussed in the second part of the paper.
In this work we demonstrate three different designs of tunable mid-infrared (MIR) beam steering devices based on multilayer graphene-dielectric metamaterials. In all designs the tunable beam steering is achieved by controlling the effective refractive index of the graphene metamaterial, which is done by changing the chemical potential of each graphene layer. The proposed beam steerer concepts allow...
A dumbbell-shaped slotted leaky-wave antenna based on composite right/left-handed metamaterial structure is proposed to improve the backward scanning bandwidth and achieve consistent gain. The antenna consists of substrate integrated waveguide (SIW) unit cells array, which is configured by a dumbbell-shaped slot, cut on the upper layer of the SIW, and an embedded patch underneath the dumbbell-shaped...
Metamaterial inspired concept is a very promising technique to miniaturize antennas suffering from their small electrical sizes while keeping a good radiation efficiency. In this paper, the theory of characteristic modes is used to perform a study of the powers and Q factors of metamaterial inspired antennas, such as the common 2D electric based monopole antenna with a meander line [1]. The aim of...
In this study to show that the paraffin-based lens can handle high frequencies for metamaterial characterization, two dielectric lenses are fabricated using a molding process for the frequency range from 10 to 18 GHz. The fabricated lenses guarantee low cost and ease of implementation compared to the other machining and material methods. To verify the proposed lens performance, two similar paraffin...
Under certain circumstances, plasmonic coatings could be a solution to the design of stealthy targets over the microwave range. In this communication, Perfectly Electrically Conducting (PEC) spheres with plasmonic coatings are studied in the microwave spectrum. Two main issues are raised. The first one is related to the fact that the exact computation of the Radar Cross Section (RCS) of finely textured...
A compact planar monopole antenna backed by an electromagnetic bandgap (EBG) structure is presented. The antenna is conformal to the human body and is intended for wearable applications in wireless body area networks. It operates at 2.45 GHz, and is fabricated on a 68mm by 38mm by 1.57mm semi-flexible substrate. The performance of the antenna does not degrade with structural bends along both of its...
This paper presents recent developments in metaline-based antennas. Four metalines are presented and application of these metalines to low-profile antennas is discussed: (A) zeroth-order metaline antenna, (B) double metaline antennas, (C) metaloop antennas, (D) metaspiral antennas, and (E) metahelical antennas. Wideband broadside radiation from double metaline antennas and dual-band counter circularly-polarized...
In this paper, some applications of metamaterial superstrates for directivity enhancement of cylindrical dielectric resonator antenna (DRA) mounted on corrugated ground plane are investigated. Three different types of superstrates, viz., split ring resonator (SRR), S-shape, and cubic high dielectric resonator (CHDR) are discussed. The metamaterial structure is used as a lens to improve the directivity...
A gradient index dielectric metasurface composed of air holes of different dimensions in a bulk dielectric, is fabricated by three-dimensional (3D) polyjet printing and is combined with inductive and capacitive copper grids to have an LC resonance. The latter metal-dielectric metasurface is then used as a phase-gradient superstrate in a Fabry-Perot cavity at microwave frequencies. Performed simulations...
We present a general methodology to arbitrarily manipulate the amplitude and phase of an electromagnetic wave propagating in a two-dimensional medium, without introducing any scattering. This leads to a class of isotropic spatially varying permittivity and permeability profiles that are transparent to an incident plane wave while shaping the field magnitude. Furthermore, we propose a metamaterial...
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