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A broadband Ku-band lens horn antenna for airborne SAR applications is presented in the paper. Several design equations, which create the geometric relation between the lens and the horn, are deduced, so the independent design variables are reduced, and the parametric sweep results can be obtained quickly in HFSS. Simulated results show that the antenna is less than 200mm in height, and its gain is...
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,...
A novel conical horn antenna loaded with ball cone dielectric is designed in this paper. The design method of the dielectric surface equation is given. The comparison between the smooth wall conical horn antenna and the four types of horn antennas, the dielectric lens-corrected horn antenna, the dielectric loaded horn antenna, the cone dielectric loaded horn antenna, and the ball cone dielectric loaded...
In this paper, a novel deterministic splitting method of ray tubes(DSMRT) based on ADRTT (adaptive ray tube tracing) is proposed to predict the indoor radio propagation characteristics. It is agreed well by a comparison of simulated results and results in literatures. The novel splitting method of ray tube shows a large improvement in computational efficiency compared by conventional methods.
This paper uses stochastic bridge processes to model the sea surface multipath propagation channel of Ka-band. That is taking the samples of stochastic bridge processes as the multipath propagation paths of electromagnetic waves. Firstly, through the analysis of the propagation environment and the radio wave propagation characteristics, get the numerical characteristics of the stochastic samples and...
Using split-step fourier transform method solving parabolic equation is an effective method for predicting radiowave propagation above earth surface. In this paper the backward difference is adopted to improve the discrete mixed fourier transform algorithm, shift map method is also introduced to consider irregular terrains. Radiowave propagation is then predicted under vacuum and non-vacuum air conditions...
In this study, the propagation path of radio wave in the sporadic E layer of the ionosphere is computed by the basic equations of ray-tracing and Runge-Kutta algorithm, which is not considering the terrestrial magnetic field or the collision conditions. From the computation results of the radio wave propagation in sporadic E layer by the method of ray-tracing, it can be seen that a reference for the...
This paper describes guide-wave characteristics of graphene based waveguides. The model of graphene conductivity is derived at first. The guided wave and the characteristics of PEC-graphene and graphene-graphene waveguides are studies in details with boundary condition defined. The dispersion equation is then derived by solving the Maxwell's equations. The propagation constant is shown with the transverse...
Appling the passive vector radiate transfer equation to build the mathematical model of single layer from random distributed spherical particles. Then the Eigen value and Eigenvector method is used to calculate the radiate brightness temperature of MIE particles and Rayleigh particles. The characteristics of the passive radiation of these two kinds of particles are observed and studied by analysis...
This paper presents a new method for the calculation of VLF propagation in the earth-ionosphere waveguide using the parabolic equation (PE) method. The PE is commonly used to solve the problem of radio wave propagation within atmospheric ducts at high frequencies. The required initial field, refractive index, and boundary conditions for the calculation of the PE under the environment of the earth...
The paper presents two inverse scattering models to achieve through wall imaging in the frequency domain. One model treats the wall as a part of inhomogeneous background medium and consequently the Green's functions for inhomogeneous background are numerically calculated. The other model treats the wall as a known scatterer placed in a homogeneous background medium and then the permittivity of the...
In this paper, we investigate the near field Orbital Angular Momentum (OAM) using the rigorous numerical methods. To model the communication channel of the OAM system, we derived a rigorous channel matrix for the near field transmitter/receiver system. This channel matrix is composed of the admittance matrices of the system. To obtain these admittance matrices, the integral equation method is employed...
Constructing parabolic wave equation model, with the algorithm of discrete mixed Fourier transform, has become the mainstream approach to describe the atmospheric duct. To determine the absorption layer top boundary of parabolic equation is the significant step of the step calculation process. This paper discusses on the relevant problems about setting window function for absorption boundary. Firstly,...
A novel near-field measurement method for predicting far-field monostatic RCS of targets is studied. With the two-dimensional problem as an example, the theory and algorithm of near-field to far-field transformation for this measurement method are derived. With the two-dimensional perfect conductor plate as the target under test, the computer simulation of this measurement method is performed. The...
In this paper we propose a method based on the Kriging surrogate modeling technique for the generation of a multi response model which determines the correspondence between the RCLG values of a generalized transmission line and the geometrical features (dimensions) of a specific frequency selective surface (FSS) or metamaterial structure (MTM) operating within predefined frequency ranges. In the past...
In this paper, a conformal high-order finite difference time-domain (CHO-FDTD) scheme is present to deal with the dielectric curved objects. The general update equations of the CHO-FDTD have been derivated. The CHO-FDTD method, based on the effective dielectric constant EDC technique, is applied in scattering cases, and the conclusion are that the scheme provides the better accuracy than the HO-FDTD...
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...
An improved Discontinuous Galerkin Time-Domain (DGTD) method based on regular hexahedron is proposed for reducing the computational complexity. The derivation process of the equations and calculation method is described. And the explicit scheme of DGTD Maxwell's curl equation based on regular hexahedron is given. By comparing with the general DGTD method, this method has a more simplified form and...
The scalar wave formulation of computation region and the first-order absorbing boundary condition are given by Maxwell's equations. Then the residuals of entire computation region are presented. The weak form solutions of wave equation are described by take integration over computation domain and its boundary. According to the principle of equivalence, the implementation of extrapolation from 2D...
In this paper, a hybrid domain decomposition method with electric and magnetic current combined-field integral equation (JMCFIE) is present for modeling electromagnetic scattering problems involving composite structures. The method first decomposes the original problem into several sub-domains according to its geometry and dielectric parameters. JMCFIE serves as the sub-domain solver in which a well-posed...
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