检索结果-内蒙古大学图书馆

Scattering from frequency selective surfaces: A continuity condition for entire domain basis functions and an improved set of basis functions for crossed dipoles

引用

IEE PROCEEDINGS-MICROWAVES ANTENNAS AND PROPAGATION 1999年第3期146卷 234-240页

作者： Poulsen, S Lund Inst Technol Dept Electromagnet Theory SE-21100 Lund Sweden

A plane wave impinges on an infinite, plane frequency selective surface (FSS) composed of crossed dipoles, and a surface current is induced on the conducting parts of the FSS. Using the established spectral Galerkin method, where the method of moment (MoM) procedure is carried out in the spectral domain, the induced current is determined, and the scattering problem is solved. The authors derive a necessary continuity condition of entire domain basis functions, and show that basis functions which do not satisfy this condition are suppressed by the spectral Galerkin method. Specifically, an improved set of basis functions are presented, designed for crossed dipoles. This set of basis functions consists of traditional even (symmetric) dipole basis functions, and a new set of V-dipole basis functions. It is found that the present basis functions are considerably more efficient than the existing basis functions for crossed dipoles. It is found that it suffices to take four of the present basis functions into account, still getting highly accurate results, even above the first resonance frequency.

关键词： Antenna theory frequency selective surfaces spectral Galerkin method Mathematical analysis Antenna arrays transmission property even dipole basis functions method of moments method of moment integral equations electromagnetic induction spectral domain Electromagnetic wave propagation Galerkin method electromagnetic wave transmission dipole antenna arrays plane wave scattering infinite array integral equation method symmetric dipole basis functions spectral-domain analysis MoM induced current Integral equations (numerical analysis) entire domain basis functions scattering problem reflection property electric current continuity condition resonance frequency electromagnetic wave scattering surface current V-dipole basis functions crossed dipoles electromagnetic wave reflection FSS

来源：评论

学校读者我要写书评

暂无评论

Analysis of Frequency Selective Surfaces on Periodic Substrates Using entire domain basis functions

引用

IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 2010年第3期58卷 876-886页

作者： Yahaghi, Alireza Fallahi, Arya Abiri, Habibollah Shahabadi, Mahmoud Hafner, Christian Vahldieck, Ruediger ETH Lab Elect Fields & Microwave Elect CH-8092 Zurich Switzerland Shiraz Univ Dept Elect Engn Shiraz Iran Univ Tehran Sch Elect & Comp Engn Fac Engn Tehran 1439515 Iran

The paper presents an efficient procedure to utilize the existing method of moments/boundary integral-resonant mode expansion approach for the analysis of frequency selective surfaces printed on periodic and inhomogeneous substrates. The Green's function matrix of the structure is obtained using a multiconductor transmission line model. The resulting series equations are solved by using the periodic method of moments with entire domain functions as both basis and test functions. The required entire domain functions are extracted using boundary integral-resonant mode expansion. The Fourier coefficients of the basis functions are evaluated from the coupling integrals by applying a coordinate transformation. Some examples are analyzed and compared to measurement data. To illustrate the excellent convergence of the method, a comparison between using entire domain and sub-domain functions is made. It is shown that by using the proposed approach not only the number of required basis functions reduces but also lower truncation orders in the Fourier expansions need to be considered. This leads to a drastic reduction of the computation time.

关键词： Boundary integral resonant mode expansion entire domain basis functions frequency selective surfaces method of moments multiconductor transmission lines method periodic structures spectral domain analysis

来源：评论

学校读者我要写书评

暂无评论

MODAL-ANALYSIS METHOD FOR BODIES OF ARBITRARY CROSS-SECTION FOR NUMERICAL COMPUTATION

引用

IEE PROCEEDINGS-H MICROWAVES ANTENNAS AND PROPAGATION 1990年第5期137卷 255-262页

作者： MOHEB, H SHAFAI, L Department of Electrical Engineering University of Manitoba Winnipeg Canada

A modal analysis method is used to investigate scattering from conducting objects of rectangular cross-section, and to determine the variation of the radar cross-section due to the polarisation or direction of the incident wave and the effect of the mode coupling resulting from crosssectional perturbation from a circular cylinder. The traditional approach of surface integral equations in conjunction with a moment method is used to solve the problem numerically. A geometric transformation is used to select entire domain basis functions for the surface current along the cross-section. Subdomain basis functions are used to represent the current component in the plane orthogonal to the cross-section. Owing to the geometric structure of the object the current modes are coupled. The degree of coupling and convergence of the modes are investigated. Representative results for objects of square and rectangular cross-sections are presented and discussed.

关键词： convergence Electromagnetic waves: theory rectangular cross-section electromagnetic scattering mode coupling surface integral equations circular cylinder surface current conducting objects polarisation moment method arbitrary cross-section cross-sectional perturbation integral equations Electromagnetic wave propagation electromagnetic wave scattering entire domain basis functions radar cross-sections Integral equations (numerical analysis) radar cross-section Numerical approximation and analysis modal analysis method numerical computation geometric transformation convergence of numerical methods square cross-section subdomain basis functions Radar theory

来源：评论

学校读者我要写书评

暂无评论

Optimized basis functions for slot antennas excited by coplanar waveguides

引用

IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 2003年第7期51卷 1638-1646页

作者： Neto, A De Maagt, P Maci, S CALTECH Jet Prop Lab Submm Wave Adv Technol Grp Pasadena CA 91109 USA European Space Technol Ctr Electromagnet Div NL-2200 AG Noordwijk Netherlands Univ Siena Dept Informat Engn I-53100 Siena Italy

A method is proposed for the analysis of slot antennas excited by coplanar waveguides. First, a standard integral equation for the continuity of the magnetic field is formulated. Then the appropriate equivalent magnetic currents of the method of moments are represented in terms of entire-domain basis functions which synthesize the resonant behavior of the slot and the field in proximity of the feeding source and of the bends. In order to define these basis functions, canonical geometries are identified, whose Green's functions have been found analytically. The accuracy and the effectiveness of the method in terms of convergence rate and number of unknowns is demonstrated by comparison with a standard fine meshing full-wave analysis.

关键词： coplanar waveguides entire domain basis functions method of moments slot antennas submillimeter wave antennas

来源：评论

学校读者我要写书评

暂无评论

Efficient analysis of quasi-optical filters by a hybrid MoM/BI-RME method

引用

IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 2001年第7期49卷 1054-1064页

作者： Bozzi, M Perregrini, L Weinzierl, J Winnewisser, C Univ Pavia Dept Elect I-27100 Pavia Italy Univ Erlangen Nurnberg D-91058 Erlangen Germany Univ Freiburg Dept Mol & Opt Phys D-79104 Freiburg Germany

This paper presents a novel algorithm for the analysis of quasi-optical filters, consisting of thick metal screens perforated periodically with arbitrarily shaped apertures. The algorithm is based on the widely used method of moments (MoM) in conjunction with entire domain basis functions. Its flexibility, accuracy, and rapidity depend on the use of the Boundary Integral-Resonant Mode Expansion (BI-RME) method in the numerical determination of the basis functions, A computer rode has been developed based on this algorithm, The analysis of two different quasi-optical filters operating at 8 GHz and 280 GHz is reported and compared with experimental data as well as with other simulations, In both cases, the whole analysis requires few seconds on a standard work-station and the theoretical results show a very good agreement with the measured data in a wide frequency band. The capability of the MoM/BI-RME approach to handle completely arbitrary shapes is highlighted in the second example. In this case, in fact, the fabrication process causes small deformations of the nominal shape of the apertures, which must be accounted for, since they play an important role in the frequency response of the filter.

关键词： coupling integrals entire domain basis functions frequency-selective surfaces numerical methods quasi-optical filters

来源：评论

学校读者我要写书评

暂无评论

Efficient representation of induced currents on large scatterers using the generalized pencil of function method

引用

IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 1996年第1期44卷 51-57页

作者： Altman, Z Mittra, R Hashimoto, O Michielssen, E Electromagnetic Communication Laboratory University of Illinois Urbana-Champaign IL USA

It is shown in this paper that the currents induced over large and smooth scatterers can often be represented by a series of complex exponentials with only a few terms. The generalized pencil of function method is employed to extract these exponentials from the numerical solution of the scattering problem derived by using the Method of Moments. Illustrative examples include a partially-coated two-dimensional scatterer modeling a helicopter blade and the three-dimensional problem of scattering by a thin plate. The ultimate objective of this effort is to solve a class of large-body scattering problems, for arbitrary angles of incidence including the grazing angle, by utilizing the numerically-derived, complex exponential type of basis functions extrapolated to higher frequencies. It is well known that the physical optics approximation for the induced current becomes inaccurate when the angle of incidence is close to grazing, and the asymptotic methods, e.g., the GTD can become unwieldy for scatterers with edge treatments and those with complex geometrical shapes, The approach based upon the use of numerically derived entire domain basis functions on a portion of the body is proposed herein as a means to circumventing this difficulty.

关键词： current distribution electromagnetic induction electromagnetic wave scattering extrapolation helicopters method of moments GTD angles of incidence asymptotic methods complex exponential complex exponentials entire domain basis functions gen METHOD OF MOMENTS Scattering GEN1 gene Electric current distribution Induced currents Electromagnetic wave scattering Electromagnetic induction asymptotic methods extrapolation method geometrical theory of diffraction angle of incidence pencil Helicopters HELICOPTER BLADES

来源：评论

学校读者我要写书评

暂无评论

Design, fabrication, and measurement of frequency-selective surfaces

引用

OPTICAL ENGINEERING 2000年第8期39卷 2263-2269页

作者： Bozzi, M Perregrini, L Weinzierl, J Winnewisser, C Univ Pavia Dept Elect I-27100 Pavia Italy Univ Erlangen Nurnberg Lab High Frequency Technol D-91058 Erlangen Germany Univ Freiburg Freiburg Mat Res Ctr D-79104 Freiburg Germany

This paper describes theoretical analysis, fabrication techniques, and measurement results for frequency-selective surfaces operating in the millimeter and submillimeter wave region. The analysis is based on the method of moments with entire domain basis functions, obtained by the boundary-integral-resonant-mode-expansion method. This method is particularly efficient and applies to the analysis of thick metal screens perforated periodically with arbitrarily shaped apertures. Three fabrication techniques are discussed and applied: photolithographic etching, galvanizing growth, and milling. Prototypes obtained with the different fabrication techniques are presented. Finally, measurements of the frequency response of the prototypes are presented, based on a new spectroscopic tool called terahertz time-domain spectroscopy. In all cases, the measurement data fit very well with the simulations. (C) 2000 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(00)03308-0].

关键词： frequency-selective surfaces method of moments entire domain basis functions photolithographic etching galvanizing growth milling technique terahertz time-domain spectroscopy (THz-TDS)

来源：评论

学校读者我要写书评

暂无评论

A Novel Periodic Characteristic Mode Analysis Method for Large-Scale Finite Arrays

引用

IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 2019年第12期67卷 7637-7642页

作者： Cheng, G. S. Wang, Chao-Fu Anhui Univ Key Lab Intelligent Comp & Signal Proc Minist Educ Hefei 230601 Anhui Peoples R China Natl Univ Singapore Temasek Labs Singapore 117411 Singapore

A novel technique, namely periodic characteristic mode (CM) analysis (PCMA) method, is proposed for the solution of CMs of large-scale finite periodic arrays. This technique first adopts a small set of CMs of the reference element of the array with larger modal significance (MS) to construct the entire-domain basis functions defined on each array element and then applies them to expand the characteristic currents of the entire array. By using these newly constructed CM-based entire-domain basis functions, the proposed PCMA method can achieve great reduction in the matrix dimension of the resultant generalized eigenvalue problem governed by the entire array structure, thereby significantly reducing the computational time and memory requirement for solving CMs of the entire large-scale finite periodic array. Several typical examples are presented to demonstrate the efficiency and accuracy of the proposed method.

关键词： Finite element analysis Microwave antenna arrays Eigenvalues and eigenfunctions Laboratories Method of moments Manganese entire domain basis functions finite periodic arrays periodic characteristic mode (CM) analysis (PCMA) method

来源：评论

学校读者我要写书评

暂无评论

Analysis of multilayered printed frequency selective surfaces by the MoM/BI-RME method

引用

IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 2003年第10期51卷 2830-2836页

作者： Bozzi, M Perregrini, L Univ Pavia Dept Elect I-27100 Pavia Italy

This paper presents an efficient method for the analysis of printed periodic structures, consisting of a multilayered array of metal patches in a stratified dielectric medium, illuminated by a uniform plane-wave. These structures are widely used as frequency selective surfaces and mirrors. The analysis is based on the solution of an integral equation by the method of moments (MoM) with entire-domain basis functions. The basis functions are calculated numerically by the boundary integral-resonant mode expansion (BI-RME) method. The patches may have an arbitrary shape, and both metal conductivity and dielectric losses are considered Some examples are reported to show the accuracy and rapidity of the proposed method.

关键词： coupling integrals entire domain basis functions frequency selective surfaces integral equation

来源：评论

学校读者我要写书评

暂无评论

Problem-matched basis functions for microstrip coupled slot arrays based on transmission line Green's functions (TLGF)

引用

IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 2005年第11期53卷 3556-3567页

作者： Bruni, S Llombart, N Neto, A Gerini, G Maci, S TNO Def Safety & Secur NL-2597 AK The Hague Netherlands Univ Siena Dept Informat Engn I-53100 Siena Italy Univ Politecn Valencia Dept Commun E-46022 Valencia Spain

Problem matched basis functions are proposed for the method of moments analysis of printed slot coupled microstrips. The appropriate equivalent currents of the integral equation kernel are represented in terms of two sets of entire domain basis functions. These functions synthesize on one hand the resonant behavior of slots, microstrips or dipoles and on the other hand the field in proximity of the feeding source and of the discontinuities. In order to define these basis functions, canonical geometries are identified, whose Green's functions have been found in semi-analytical form. The accuracy and the effectiveness of the method in terms of convergence rate and number of unknowns is demonstrated by comparison with a standard fine meshing full-wave analysis. The method is extremely convenient for large arrays, where the subwavelength details should be treated together with large global dimensions. Since the proposed solution is independent of the dimensions of these details, it provides dramatic reduction of the number of unknowns and improvement of condition number.

关键词： entire domain basis functions Green's functions method of moments (MoM)

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：