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This paper introduces the research of applications of metamaterial-based antennas recently developed in our lab. They include the planar antennas with multi-band multi-function operation, high gain property and enhanced beam scanning ability.
A coupled-fed printed antenna for eight-band covering WWAN/WLAN/WiMAX operation in the mobile phone is presented. The proposed antenna consists of a long radiating strip, a short-circuited inductive shorting strip, and a coupling strip to capacitively excite the radiating strip. By using the capacitive excitation, the long radiating strip with the shorting strip can generate a wide lower band to cover...
This article demonstrates the design of a meta-surface Luneburg lens antenna with flared structure. The lens antenna is composed of two flared metallic cones, a metasurface Luneburg lens and a reflection plate. The refraction index of Luneburg lens can be obtained by gradually changing the radius of patch arraying on the substrate. Such an antenna structure is easy to implement with low fabrication...
This article presents a novel plate Luneberg lens which is based on the parallel plate waveguide filled with drilled dielectric material. To obtain effectively refractive index distribution, several small holes of nonuniform density are drilled in this dielectric. In order to meet Luneberg Law's requirement on the edge region, the thickness of the substrate is modified by the boundary conditions of...
A monopole antenna fed by a coplanar waveguide (CPW) operating at triple-band is presented in the paper, in which the two different monopoles can be used to obtain triple-band. The first resonant frequency f1 is controlled mainly by the length of the longer monopole. The second resonant frequency f2 is mainly decided by the length of the shorter monopole. The third resonant frequency f3 is controlled...
A wideband 60 GHz on-chip triangular monopole antenna with artificial magnetic conductor (AMC) in CMOS process is presented. The AMC inserted between the lossy substrate and antenna acts as a shield to minimize the loss induced by the CMOS substrate. Both the AMC and monopole antenna are optimized to deliver a wideband operation covering all 60GHz MMW band. AMC plane in different size are studied...
A new algorithm for ray tracing that called “minimum included angle algorithm” was proposed in order to analyze airborne antenna layout optimization. First of all, the discrete surface was divided into triangular meshes to generate surface grid data that accorded with the format that was required in this article. The “minimum included angle algorithm” was used to process the data mentioned above....
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 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,...
In this paper, a real-time voltage control platform, based-on genetic algorithm (GA) program, is built to optimize a 32-element high gain beam-forming antenna. After 500 generations, S21 has been significantly improved. The gain of the antenna has promoted to 8.95dBi, and the beam-width of the antenna has narrowed down to 30°.
Free space methods for electromagnetic compatibility (EMC) antenna calibrations at Open Area Test Site (OATS) are not suitable for monopole antennas due to corresponding large wavelengths in low-frequency bands. As an alternative, the Equivalent Capacitor Substitution Method (ECSM) is commonly adopted now. In this paper, a major uncertainty factor of capacitance accuracy is investigated by simulation...
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...
In this paper, a sparsified multilevel adaptive cross approximation (SMLACA) is proposed to improve the sparsified adaptive cross approximation (SPACA). Compared with the SPACA, the SMLACA can save the CPU time and memory requirement for large targets. Numerical results are presented to validate the SMLACA and demonstrate its merits.
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.
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...
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...
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