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The radiation from a spherical antenna immersed in a plasma shell has been studied. In infinite plasma shell, when the electromagnetic wave frequency is greater than the plasma frequency, the electromagnetic wave can through the plasma layer enclosing the antenna. On the contrary, the radiation cannot pass the plasma layer. However, when the boundary conditions are considered, a strange phenomenon,...
Wireless communication is very important for the safety production in coal mine. In this paper, the novel analysis method for polarization modes on wireless communication in coal mine tunnel using reflection coefficient and transmission coefficient is presented, and we suggest packet-level adaptive interleaved forward error correction(I-FEC) at the application layer for improving the communication...
As UHF RFID technology is employed in all walks of life, the working environment of UHF radio frequency identification system is complex, the blocks between the reader and the electric tag is an important factor. Based on application, the radiation field is analyzed and compared using CST Microwave Studio under existence or absence of occlusion between the reader and the electric tag.
This paper analyses the characteristics of the absorbing material. Target structure uses S-parameter inversion to obtain equivalent permittivity and equivalent permeability. The paper analyses the absorbing properties of the structure, it also pays attention to the energy dissipation. Finally, the result improves the absorbing structure to gain better electromagnetic properties.
In this paper, a new modeling procedure for the integral equation-based non-overlapping domain decomposition method (IE-NDDM) is proposed. First the integral equation is established on the entire PEC surface, then the entire surface is partitioned into some non-overlapping open-surfaces (called subdomains). The RWG basis functions are used to expand the equivalent surface electric current on the entire...
In this paper, an IE-ODDM with higher-order hierarchical Legendre basis functions is proposed for solving the scattering from an electrically large PEC object. Because higher-order basis functions are employed, the sizes of the meshes can be selected larger. Thence, even though the area of each subdomain is relatively larger, the number of unknowns involved in the subdomain is relatively smaller compared...
This paper presents a forward approach to construct three-dimensional (3 D) electromagnetic parametric scattering model for a known complex radar target based on its geometrical CAD model. Similar to component disassembly method (CMD), we extract strong scattering source based on the components decomposition of complex target but fully considering the mutual coupling between the components, with reference...
The paper gives the digital generation model of the soil, sand and cement of rough ground, while introducing near-field three-dimensional antenna direction data, deduces the Kirchhoff s near-field formula and calculates the near-field scattering coefficient of rough ground by the means of simulation. Finally, by comparison with the measured data, the correctness and validity of the models can be proved.
This article acquires the microwave imagery of target through simulation, bases on ISAR imagery of complex target, and adopts the CLEAN method to extract the strong scattering point of target imagery; meanwhile, combine the non-uniform illumination under missile-target encounter conditions, respectively obtain the distribution parameters of target scattering points at various miss distance, providing...
Synthetic basis function method is a cutting-edge technology in analyzing the scattering problem of arbitrarily complex objects. Compared with the traditional method of moment, it significantly reduces the memory requirements of the system, and is especially suitable for solving problems of periodic structures. In this paper, synthetic basis function method is implemented and verified. Besides, further...
This paper reports a polarization selective one-way microwave absorber based on composite metamaterial slabs. The polarization selective one-way absorber allows a linearly polarized electromagnetic wave to be absorbed along one particular incident direction and to penetrate through it along the opposite direction. For the cross-polarized wave, the direction dependent propagation properties are reversed...
In this paper, a flat meta-surface constructed by an ensemble of unit cells using I shaped resonant structure is proposed and designed to provide phase discontinuity for electromagnetic wave front manipulation. We demonstrate experimentally that electromagnetic wave deflection is achieved in compliance with the generalized Snell's law at the designed frequency band (around 10 GHz). In addition, the...
A fast algorithm based on hierarchical matrix (H-matrix) is addressed to solve electromagnetic scattering from 3-D electrically large object with arbitrarily shape. According to the admissibility condition of H-matrix framework, the moment-method-based coefficient matrix is divided into near-field and far-field interaction blocks, which are approximated by interpolation degenerate kernel functions...
In this paper, an optimization technique combining non-conformal integral equation domain decomposition method (IE-DDM) and particle swarm optimization (PSO) is presented for the design of antenna on platform. The antenna and the platform can be decomposed into different closed sub-domains according to design requirements and the DDM is used to compute the scattering from antenna on platform. Meanwhile...
The measurement on scattering characteristics of large complex target is always restricted by expensive cost, venues and environment, and the scattering characteristics of the full-scale can be obtained by measuring the scattering characteristics of the scale-model. The scale relation of electromagnetic scattering from electrically large target is given based on the method of equivalent edge currents...
The composite electromagnetic scattering problem from the randomly rough sea surface and the missile-like target is effectively analyzed by the Extended Propagation-Inside-Layer Expansion (EPILE) combined with Forward-Backward method (FBM) scheme. The formulation of the composite scattering is given, the efficiency and accuracy of adoptive algorithm are verified, and different scattering characteristics...
In accordance with the ideas of sub-domain, we proposed a time domain iterative hybrid method based on the Finite Difference Time Domain (FTTD) and time domain physical optics theory (TDPO) according to electromagnetic scattering from electrically large conductor and local structures materials. The mutual coupling scattering between structures was analyzed and parallel collaborative research method...
In this paper, Physical Optics (PO) is used to calculate the electromagnetic scattering of electrically large complex target and background. Two dimensional surface is simulated by using spectral method based on PM spectrum. Then, the target and rough surface model are combined together to be a very accurate composite model, after which surface mesh is generated with the information of incidence frequency...
This paper describes the electromagnetic scattering model with concrete pavement and scattering properties of layered equivalent to a single exponential model of the electromagnetic spectrum engineering rough surface scattering, and then introduced the experimental method to measure the scattering coefficient of cement, the experimental apparatus and measurement system, and then later by the experimental...
Lombardini et al. [1] have demonstrated that the ripples on a sea surface covered by oil films exhibit a damping effect. The damping effect reduce the RMS slope and RMS height of the sea surface, and thus have an influence on the electromagnetic scattering features, as well as the Doppler spectra signature of the backscattered returns from dynamic sea surface. Consequently, electromagnet tic scattering...
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