摘要:

In this paper, some improvements of the Discretized Mie-Formalism will be given. The main objective is to derive an iteration procedure which results in less computational effort and a more stable numerical algorithm. In this way, a treatment of higher size parameters and larger aspect ratios become possible. As a side effect, we will be able to discuss the range of validity of the Rayleigh hypothesis from the point of view of the DMF. These improvements are achieved by a reformulation of the transformation process within the Method of Lines for non-separable boundary value problems.

ISSN:0920-5071    

DOI:10.1163/156939397X00990

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

We present and compare two integral-equation formulations of the TE eigenvalue problem of a ridged circular waveguide. In the E-formulation, an integral equation for the tangential electric field Eø. is derived and solved by the moment method using basis functions which include the edge conditions. The H-formulation relies on an integral equation for the axial magnetic field Hz, which is also solved by the moment method and basis functions with edge conditions. Spurious roots are encountered in the E-formulation whereas the H-Formulation is free from spurious roots but requires larger matrices. Results from both formulations are compared with previously published data and analytic results for limiting cases, excellent agreement is demonstrated.

ISSN:0920-5071    

DOI:10.1163/156939397X01007

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

We consider the following scattering problem: An arbitrarily polarized plane wave, propagating in an unbounded bianisotropic space, is obliquely incident on an array of parallel bianisotropic cylinders which are enclosed by another bianisotropic cylinder. The boundary value problem is formulated in terms of a set of two coupled second order differential equations. The solution technique combines the method of separation of variables with the translational addition theorem. The matrix elements of the resulting linear algebraic system are given by single-term analytical expressions. Numerical examples are presented for several cases along with comparisons with previously published results.

ISSN:0920-5071    

DOI:10.1163/156939397X01016

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

This article considers the problem of ultra-wideband signal scattering on a half-space representing layered-uniform environment with arbitrary complex permeability of layers. The method developed in the article permits to calculate the ultra-wideband response in any point of the mentioned half-space, as well as signal reflected from its boundary.

ISSN:0920-5071    

DOI:10.1163/156939397X01025

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

An accurate determination of the series resistances with physical meaning is extremely important for the characterization and modeling of FET's. In this paper, we discussed the bias-dependent behavior of the source and gate resistance of GaAs MESFETs. A new analytical method is presented to extract these resistance at all bias conditions from measured S-parameters. This method enables the calculation of the equivalent circuit elements quickly. An application of this new technique to extract the source and gate resistance of GaAs MESFET reveals a bias-dependent behavior for both resistance. The influence of bias on these resistance is significant under all bias conditions and must be carefully estimated if an accurate modelling of the MESFET behavior is required.

ISSN:0920-5071    

DOI:10.1163/156939397X01034

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The general expressions of the spectral-domain dyadic Green's functions for an inhomogeneous cylindrical waveguide and an inhomogeneous cylindrical cavity are formulated by the method of eigenfunction expansion and scattering superposition. The excitation current source can be in an arbitrary region. The dyadic Green's functions are used to calculate the phase constants and the cut-off characteristics of a dielectric-loaded cylindrical waveguide and the resonant frequencies of a dielectric-loaded cylindrical cavity. Complete agreement with published data is obtained.

ISSN:0920-5071    

DOI:10.1163/156939397X01043

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

An alternative formulation for guided electromagnetic fields in grounded chiral slabs is presented. This formulation is formally equivalent to the double Fourier transform method used by the authors to calculate the spectral fields in open chirostrip structures. In this paper, we have addressed the behavior of the electromagnetic fields in the vicinity of the ground plane and at the interface between the chiral substrate and the free space region. It was found that the boundary conditions for the magnetic field, valid for achiral media, are not completely satisfied when we deal with chiral material. Effects of chirality on electromagnetic field distributions and on surface wave dispersion curves were also analyzed.

ISSN:0920-5071    

DOI:10.1163/156939397X01052

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The dyadic Green function for an anisotropic, inhomogenous medium is reformulated as a double differential form by embedding material properties in the Hodge star operator. This formalism simplifies the manipulation of differential operators in the anisotropic case. An integral equation is obtained which relates the Green form for the electric field to a generalization of the usual free space scalar Green function.

ISSN:0920-5071    

DOI:10.1163/156939397X01061

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

This paper describes the application of a finite volume method in the time domain, for studying the scattering of a "complex" object. The principle of the finite volume scheme is explained. A finite volume code allows a conformal meshing and composite materials can be considered with no particular problem. Different comparisons are made with other numerical methods, in order to validate the introduction of imperfectly conducting materials in our model, and the possibility of applying a dielectric constant to some parts of the computational space. A thin-wire formalism has been introduced in the code and the results are compared with those of other numerical codes. The experiment simulated by the code is described, and the experimental and numerical results are compared.

ISSN:0920-5071    

DOI:10.1163/156939397X01070

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

ISSN:0920-5071    

DOI:10.1163/156939397X01089

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor