We present an analytical study in the structure-modulated plasmonic angular momentum, which is trapped in the core region of a sectorial indefinite metamaterial. This metamaterial consists of periodically arranged metal-dielectric nano-wedges along the azimuthal direction. Employing a transfer-matrix calculation and a conformal-mapping technique, our theory can deal with an arbitrary number of ...

Material properties in radio frequency and microwave regimes are limited due to the lack of molecular resonances at these frequencies. Metamaterials are an attractive means to realize a prescribed permittivity or permeability function, but these are often prohibitively lossy due to the use of inefficient metallic resonators. All-dielectric metamaterials offer excellent potential to overcome the...

This paper presents the design of a compact rectangular dielectric resonator antenna (RDRA) for wireless applications. A metal plate has been attached to top surface of the RDRA to achieve significant reduction in the resonant frequency of the antenna. A simple microstrip feeding mechanism has been used to excite this compact rectangular DRA. Performance parameters such as resonant frequency, i...

Based on precursor powders with a size of 200-300 nm prepared by the low-temperature solid reaction method, phase-pure YFeO₃ ceramics are fabricated using spark plasma sintering (SPS) at different temperatures. X-ray diffraction (XRD) and scanning electron microscopy (SEM) reveal that the high-purity YFeO₃ ceramics can be prepared using SPS, while the results from X-ray photoelectron spectrosco...

The refractive index of a conventional dielectric layer can be enhanced using an Artificial Dielectric Layer (ADL). Here we present the fabrication of low temperature PECVD Silicon Carbide (SiC) membranes with very high refractive index (up to 5 at 1 THz) in the terahertz frequency range. The SiC deposition parameters have been tuned to reach a very low residual stress level (-25 to 100 MPa). T...

Inside of a hyperbolic medium, the principal components of the permittivity tensor have opposite signs causing the medium to exhibit a 'metallicbr' type of response to light wave sin one direction, and a 'dielectric' response in the other. Our study shows that inside hyperbolic media, volume plasmon polaritons (VPPs) propagate along the characteristic planes, forming distinct, directionally dep...

1 − x)Pb(Mg1/3Nb2/3)O3−xPbTiO3 (x = 0, 5, and 10 mol%) ceramics were prepared using a conventional mixed oxide solid state reaction method. The low-temperature relaxor behavior of (1 − x)Pb(Mg1/3Nb2/3)O3–xPbTiO3 ceramics were examined in the temperature range from 120 to 523 K. A broad dielectric maximum that shifted to higher temperatures with increasing frequency, signified the relaxor-type b...

Microwave tomography has been proven to successfully reconstruct the dielectric profile of a human breast when used in breast imaging applications, thereby providing an alternative to other imaging modalities. However, the method suffers from high computational requirements which restrict its use in practical imaging systems. This paper presents a novel parallelization strategy to accelerate mi...

Lead-free 0.98(Na0.5K0.5)NbO3-0.02Ba(Zr0.52Ti0.48)O3 [0.98NKN-0.02BZT] ceramics were fabricated by the conventional mixed oxide method with sintering temperature at 1,080°C to 1,120°C. The results indicate that the sintering temperature obviously influences the structural and electrical properties of the sample. For the 0.98NKN-0.02BZT ceramics sintered at 1,080°C to 1,120°C, the bulk density i...

Effectively controlling quantum mechanical tunneling through an ultrathin dielectric represents a fundamental materials challenge in the quest for high-performance metal-insulatormetal (MIM) diodes. Such diodes are the basis for alternative approaches to conventional thin-fi lm transistor technologies for large-area information displays, [ 1 , 2 ] various types of hot electron transistors, [ 2–...