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Waveguide multimodal measurement of material constitutive parameters (permittivity and permeability) is designed for the unique and simultaneous determination of both permittivity and permeability. A rectangular waveguide coupler with 4 coaxial-line probe antennas and square cross section is used to decouple the TE10, TE01, TE11 and TM11 modes. The excitation and measurement of multimodal signal needs...
The collimating and resonant properties of a two-shell radially symmetric dielectric lens are studied in 2-D formulation using exact series solution. It is demonstrated that such a lens built from standard low permittivity materials can compete with the classical uniformly-layered multi-shell Luneburg lens in terms of collimating capabilities provided the layer thickness is properly selected. The...
Various studies of specific absorption rates (SARs) using liquid phantoms imitating human body tissues have been widely carried out in electromagnetic compatibility (EMC) research fields. In order to establish accurate SARs for measurement, a faithful mockup of human body tissue is needed. Therefore, knowledge of the accurate measurement of sample materials with high permittivity and high loss is...
We researched the design for RFID tag's antenna of clothing management in this paper, and encapsulation materials how to influence the quality of label, we also analyzed how to select the encapsulation materials. The paper describes the performance parameters and characteristic of the label at the end. This article focuses on the design of encapsulation materials and tries to provide practical advice...
The 3D FDTD simulation of wave EM propagation in large structures like the cometary nucleus of 67P/Churyumov-Gerasimenko is computationally expensive. With other approximative methods not all propagation phenomena can be sufficiently modeled. We propose to use the PSTD. This method overcomes the computational burdens and memory demands of the FDTD, while it allows accurate modeling of wave propagation...
This paper gives a description of the radiation quality factor and resonances of spherical antennas with material cores. Conditions for cavity and radiating resonances are given, and a theoretical description of the radiation quality factor, as well as simple expressions describing the relative increase in quality factor due to the effect of the internally stored energy are given in special cases...
We present a scheme to realize an undetectable reflector antenna. Discrete coordinate transformation is employed to design an `invisible' carpet cloak which is functional to hide objects underneath. A parabolic reflector located under the designed carpet cloak is rendered undetectable to the external observers whilst still possessing its radiation characteristics. Furthermore, a novel kind of underground...
Spherical active coated nano-particles comprised of a silica nano-cylinder core covered with a plasmonic nano-shell are investigated with regard to their near- and far-field properties. The source of excitation is taken to be that of a tangential or a radial electric Hertizan dipole while three different plasmonic materials are employed for the nano-shells, namely silver, gold and copper.
Scattering-type scanning near-field microscope has been important to increase the resolution and overcome the limitation of Rayleigh criterion about the wavelength in the far field. Millimetre- (30 - 300GHz) and Terahertz- (300 - 3000GHz) waves provide unique opportunities for the development of novel applications in the active near-field imaging and spectroscopy of microscopic objects. In this paper,...
An analytical study of heterogeneous substrates created by including small particles arranged in a cubic lattice within a host medium is presented in this paper. Rapid advances in nanomaterial fabrication techniques will allow in the near future, heterogeneous samples to be created with nano or micro-sized inclusions, and this paper investigates the electromagnetic (EM) properties of these structures...
We demonstrate that in simply connected apertures containing a meta-material with extreme anisotropy all modes become purely transverse electro-magnetic modes, are dispersion-free, and have zero cutoff frequency. We show a meta-material design using existing materials.
In this work, we study for the first time the nonlinearity of AlN piezoelectric material subjected to high RF electric field (E). Nonlinear effects in BAW (Bulk Acoustic Wave) resonators are seen as a frequency shift and an amplitude variation at the resonance (fr) and anti-resonance (fa) frequencies. Moreover the coupling factor increases for high power measurements (high E). By model fittings, these...
Delay time measurements, e.g. time domain reflec-tometry (TDR), are a well-established method for the measurement of permittivity in various materials, especially soils [1]. However, common measurement systems only provide an average value of the dielectric constant along the length of the TDR sensor. Furthermore the accuracy offered by common TDR measurements is limited due to multiple reflections...
In order to characterize dielectric materials having very high permittivity (εr ≈ 40–140) through a non destructive method, and derived from a resonant cavity is proposed and the determination uncertainties are evaluated.
Plasmonic structures are very attractive in many applications. From other side numerical simulations of plasmonic structures are very demanding and expensive in terms of memory and CPU time, making the selection of a suitable numerical method for the field computation important. The numerical problems are caused because optical nanostructures based on metal parts exhibit strong material dispersion,...
Recently, the boundary conditions that require canceling of the normal components of electric flux density (D) and magnetic flux density (B) at the boundary surface have been proposed theoretically. These new boundary conditions are labeled as DB-boundary conditions. Depending on the polarization of incident plane wave (TE or TM), DB surface behaves either as PEC or PMC surface, respectively, while...
Based on the theory for small fields superposed on finite biasing fields, the finite element model of a high frequency, double-layer plate, thickness-shear vibration pressure sensor under biasing field is set up, and a biasing field finite element method (BFFEM) is proposed. Both ends of the piezoelectric plate, vibrating in thickness-shear mode, are subjected to bending moment and axial force, excited...
An analytical study of artificial materials created by embedding spherical nano-particles in an infinite homogenous medium is presented in this paper. Propositions by various contributors to this area of the nanomaterials' field have been compared with respect to their approaches in finding the effective constituent parameters, over wide frequency ranges. Their closed form equations were examined...
Hexagonal base pyramid microwave absorber is the new design of microwave absorber. In this work, two sub-shapes are considered to compare it reflection loss performance. The shapes are hexagonal and truncated hexagonal base pyramid. Three sample of agricultural waste are used that is rice husk, rice straw and banana leaves. Before that, free space measurement technique is applied to define the dielectric...
Sensing liquids and their contaminations is very important for many applications. In this paper, the LC-resonance response of circular split rings illuminated with a normal incidence light is analyzed. The tuning response of the resonant frequency upon loading various samples of liquids is described. The liquids are deposited on the array of the rings. The sensor allows to extract various information...
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