摘要:

An accurate numerical solution for the electromagnetic scattering from a periodic array of a finite number of conducting strips is presented, where the incident plane wave propagates in an arbitrary direction. Both TM and TE polarizations are treated. First, the boundary value problem is formulated into the solution of a set of Fredholm integral equations of the first kind with singular kernels. Then it is regularized to a set of the second kind equations which is numerically solved by the moment method. The present method is much more effective than the moment solution of the first kind equations. This is because the kernel functions of the resulting second kind equations are bounded and smooth, and because the edge condition is automatically taken into account in the course of the regularization. Some numerical examples are shown for the total scattering cross-sections, surface current distributions, and the far-zone scattered fields. The near zone fields are compared with the experimental data.

ISSN:0920-5071    

DOI:10.1163/156939391X00680

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The scattering coefficients of a T-junction between rectangular and circular waveguides, coupled through a longitudinal slot in the narrow wall of the rectangular waveguide, are determined using moment method formulation, for excitation applied to the rectangular guide. The amplitude coefficients of the slot field distribution, computed in the process of determining the scattering coefficients, are used for the evaluation of the field distribution in the aperture plane of the coupling slot. The reflection and transmission coefficients, coupling as well as the equivalent network parameters are evaluated from the scattering coefficients, taking the effect of wall thickness into account. Comparison between the theoretical and experimental results on coupling and VSWR are presented.

ISSN:0920-5071    

DOI:10.1163/156939391X00699

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Electromagnetic field plots are provided for isotropic and anisotropic layeredclosed microstrip and suspended planar structures. These are hybrid mode generated field plots and include the effect of frequency dispersion. The problem of determining the fields where poor convergence may occur is covered in terms of a Mellin transform method.

ISSN:0920-5071    

DOI:10.1163/156939391X00707

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Reflection from a rotating optical fiber is analyzed. It is shown that there are angles where the variation in the reflected power due to rotation is significant and it may be measurable even for relatively low angular velocities as 30 m/sec. The total variation in the reflected power is zero. We also determine the relation between the field (average) angular momentum and the (average) power carried away by each angular harmonic.

ISSN:0920-5071    

DOI:10.1163/156939391X00716

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

We revisit here an old but neglected approximate analytic solution to the electromagnetic wave equation. Our method of derivation is reminiscent of the WKB methodology but the solution, although approximate, is much more accurate than the traditional WKB solution and can be used with almost as much ease. The method is extremely powerful but, to our knowledge, has never been used by the optics community, where its use in analyzing optical fibers and integrated optical waveguides would be beneficial.

ISSN:0920-5071    

DOI:10.1163/156939391X00725

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

An iterative technique based on the method of least squares and utilizing variational trial functions is presented. It is applied in the solution of scattering problems involving arbitrarily shaped homogeneous or inhomogeneous penetrable obstacles, utilizing a volume formulation and the k-space approach. The method minimizes a squared error over subspaces of the range of the operator, and is guaranteed to converge under certain conditions. For the class of problems for which it was designed, namely scattering problems for dielectrics using a volume formulation, the method performs better than other iterative techniques. Numerical results are presented for infinitely long homogeneous circular cylinders with TE plane wave excitation. A comparison of the performance of the iterative technique with the conjugate gradient method is made. Modifications of the iterative method which involve increasing the number of trial functions are discussed and numerical results are presented which demonstrate the effects of the modifications.

ISSN:0920-5071    

DOI:10.1163/156939391X00734

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

In this paper, the concept of analytical continuation is utilized to generate the electric field over a wide frequency band. The problem of interest is TM scattering from a conducting cylinder. A method of moments formulation is utilized to generate information about the current and its derivatives at a specific frequency. This information is utilized to extrapolate the current at other frequencies. The numerical results presented are in good agreement with exact data.

ISSN:0920-5071    

DOI:10.1163/156939391X00743

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:0920-5071    

DOI:10.1163/156939391X00752

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:0920-5071    

DOI:10.1163/156939391X00761

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor