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The nonlinear response of silver nanoparticles filled epoxy resin composites under increasing applied voltage is investigated. The influence factors of applied high voltage on the conductivity of composites are measured by the collection of the electric current passing through the sample. With the increase of applied voltage, the composite has a nonlinear conductive characteristic. The contributing...
The parabolic equation (PE) method is derived from the wave equation, and it has been widely used to solve electromagnetic wave propagation problems. In recent years, it was realized that the PE method can also be applied to scattering problems. The PE method meets the demand for higher efficiency and accuracy at the same time when there are limited computational resources. In this paper, both co-polarized...
Microwave heating usually leads to non-uniform temperatures due to the existence of drastic variation of electric field. In this study, a numerical method combined with integral equation and spectrum analysis is proposed to find its generation condition. Results show that the electric field is generally unstable, and a tiny shift in microwave frequency, permittivity of dielectric object or cavity...
In this paper, the modeling and simulation of the electromagnetic environment of shipboard equipment is studied. The electromagnetic environment simulation of the ship is carried out on the basis of establishing the sea surface and the ship model and under the different electromagnetic physical quantity. Sea and ship models will be drawn by CAD software, obtaining the electromagnetic simulation results...
This paper proposes a convenient approach to control the electromagnetic waves inside horn antennas to improve their radiation performance by placing a metasurface lens inside the horn. The lens consists of two identical metallic dipole arrays printed on both sides of a single dielectric layer. Through full-wave electromagnetic simulations, a comparative study of the enhanced radiation properties...
A novel structure of meta-surface with the function of high gain polarization conversion is proposed and studied. The meta-surface consists of 16 radiating elements, which are 4×4 periodically arranged under the Rogers substrate. In this paper, the high gain and radiation conversion mechanism of meta-surface are analyzed from the aspects of transmission phase and transmission amplitude of the microwave...
In this paper, a three-dimensional Lorentz-FDTD method has been presented to analyze the radiated fields of a high-speed moving dipole at an oblique incidence. By comparing the numerical results and the analytical results, the accuracy and validity are verified.
In this paper, we design an all-dielectric polarization conversion metasurface using high-permittivity ceramics. The metasurface is composed of 2D arrays of ceramic resonators. A nearly 1 GHz polarization conversion is demonstrated in 3.68–4.64GHz. Since such polarization conversion metasurface are made of high-permittivity ceramics, they are of important values in high-temperature or high-power applications...
An approximate method to calculate the horizontal electric field at ground level from inclined lightning channel in frequency-domain is proposed based on the extension of Cooray formula. The validation results show that the deviation of the extended formula is closely related to the observation distance and the ground conductivity. The bigger the observation distance or the ground conductivity is,...
In order to meet the requirements of fuse's digital simulation in Missile-target Encounter, an algorithm based on PO and PTD and GO methods is presented for calculating the echo characteristics of fuse, including pulse echo power and signal and the near-field RCS. Numerical results prove the proposed method high efficiency. It would be especially valuable in engineering application.
In this paper, flexible electric-field-coupled-LC (ELC) resonator for ultrathin microwave absorbing is designed. The microwave absorber consists of three layers: periodic-arrangement ELC resonators, 1.1mm FR-4 substrate and background metallic plane. Single-band, dual-band and triple-band absorber are achieved by scaling the ELC resonators in frequency range of 5–20 GHz. Current distribution, excellent...
In this paper, we designed single band tunable metamaterial absorber (MMA), which includes of periodic array cube ferrites and metal ground plane. The cube ferrite act as resonant cell, when incident electromagnetic wave and applied magnetic field are all together act on absorber, cube ferrite can produce ferromagnetic resonance (FMR) under some condition, which result in the perfect absorption. By...
A shooting and bouncing ray (SBR) method for dielectric media is presented in this paper. The tracing rays are used to approximate the electromagnetic wave in this method. The transmission/reflection coefficients of the dielectric media are induced to calculate the attenuation during the propagation. The proposed algorithm is able to calculate the radar cross section (RCS) of dielectric media. Several...
In this paper, a new form of noncoplanar optical bow-tie shaped nanoantenna structure is proposed, analyzed, and further arranged in array to investigate their near-field enhancement properties. The noncoplanar design not only improves the near-field electric field enhancement performance by 33% compared with that of the coplanar form, but also achieves better compatibility with subsequent conversion...
In this work we present numerical investigations of a novel terahertz (THz) photoconductive antenna with embedded electrodes using COMSOL Multiphysics software package. Simulation results indicate that the proposed THz antenna can store two times more effective electric energy than the conventional photoconductive antenna with planar electrode structures. These results suggest higher THz power could...
The design and operation principle of the ring antenna array for monitoring are considered. Ring radiators array and signal processing unit diagram that separates the right and left-handed circular polarization field are constructed.
In the case of stone relics with cultural heritage value that are exposed to the adverse effects of direct exposure to weathering, we present a metamaterial with a composite structure that can passively control the transmittance of infrared and visible light. This periodic multi-layer structure consist of metal and dielectric layers, these have the function of low transmittance at infrared wavelengths...
The method of partial overlapping regions is demonstrated as a modification of the alternating Schwarz's technique. The presented approach uses overlapping region concept to reduce a boundary-value problem for the scalar or vector Helmholtz's equation to a Fredholm's second kind integral equation which can be easily algebraized by means of Galerkin's technique. Applications of the method to printed-circuit...
High-density packaging of fast-switching power semiconductors typically requires low parasitic inductance, high heat extraction, and high thermo-mechanical reliability. High-density packaging of high-voltage power semiconductors, such as 10 kV SiC MOSFETs, also requires low electric field concentration in order to prevent premature dielectric breakdown. Consequently, in addition to the usual electromagnetic,...
This paper presents the implications of the new low frequency radiated emission requirements and how they have been stated for the Solar Orbiter mission so the impact in the design, verification and testing process for the Antenna Pointing Subsystem for the Solar Orbiter and future space missions. The control of Low Frequency Radiated Emission (E-field and H-field) is getting more importance in the...
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