摘要:

We analyze the radiation characteristics of multiple circumferential slots on a coaxial cable with a layer of dielectric or plasma. A set of simultaneous equations for the modal coefficients is obtained. Numerical computations are performed to show the radiation and reflection in terms of dielelctric constant and slot geometry.

ISSN:0920-5071    

DOI:10.1163/156939300X00888

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

By applying scattering superposition principle and the Waterman's T-Matrix approach, a vector wave function expansion representation of dyadic Green's functions (DGF) is obtained for analyzing the radiation problem of a current source in proximity to a perfect conducting body of arbitrary shape. In the case of a conducting sphere,the general representation derived in this paper reduce to the same analytical expressions as obtained by using separation of variables method. Computations are implemented in Mathematica package for a dipole radiating in the presence of conducting spheroids and superspheroids.

ISSN:0920-5071    

DOI:10.1163/156939300X00897

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

A prism coupler filled with nonlinear Kerr-like material is studied theoretically. A simple, approximate analysis is developed to predict its behavior in both linear and nonlinear optics. In a wide range of incident amplitude magnitude, optical bistability and multistability are found. As far as field map not undergo drastic change, the simpler approximate theory is able to quantitatively analyze both prism couplers and waveguide in nonlinear optics and to study such effects as nonlinear phase shift, existence of nonlinear asymmetric modes in symmetric environments, bi-and multistability. The predictions of the analytical theory are compared with the results obtained via numerical integration of Maxwell equations and they agree quite well.

ISSN:0920-5071    

DOI:10.1163/156939300X00905

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

For many years, the electromagnetic radiation and the plane wave scattering by various dielectric objects have been considered as two different subjects and theoretical formulations for analyzing the radiation and scattering problems also differ. This paper establishes a bridge between the radiation and scattering theories. Instead of an isotropic medium, chiral media have been considered as dielectric materials used for fabricating the planar, cylindrical, and spherical objects if multilayers. In the analysis, the electromagnetic plane waves of parallel and perpendicular polarizations are equivalent to radiated waves due to two differently polarized electric sources located at infinity. The volumetric current distributions of the two sources at infinity are thus obtained. Instead of considering the electromagnetic plane wave scattering, we can analyze the electromagnetic radiation due to the electric sources at infinity for the field distribution elsewhere outside of the scattering objects. To verify the transform, the method of vector wave eigenfunction expansion is utilized to derive electromagnetic scattered fields by such structures. Also, the electromagnetic

ISSN:0920-5071    

DOI:10.1163/156939300X00914

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

A recursive single source surface integral equation formulation for the problem of electromagnetic wave scattering by multiply-nested bodies yields an equivalent outer surface model that is independent of the material and the illumination in the exterior region, and therefore invariant under rotation and translation. The proposed algorithm is applicable to both far-field and near-field problems, and also gives, through a fast backward recursion, the field values at interior points. Such a reduced model may be duplicated and reused in an assortment of complex scattering problems without repeating the reduction calculation. Thus, the high computational efficiencies realized by the recursive formulation, with respect to the previous, direct, single source surface integral equation formulations, are further enhanced for problems involving some degree of repetition, as in geometry and material optimization of scattering structures under various types of illumination. Numerical examples are included in order to demonstrate the features and the efficiency of the recursive multiply-nested algorithm in comparison to direct, simultaneous solution of all unknowns by the electric field integral equation method.

ISSN:0920-5071    

DOI:10.1163/156939300X00923

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

A new kind of stripline microwave high pass filter is proposed in this paper. Striplines here used have a tapered inner conductor and are filled by inhomogeneous dielectric materials with continuous spatial variation of the refraction index. Thus, filtering properties of such components can be controlled by means of two different keys: the inner conductor taper and the refraction index spatial variation of the dielectric material filling the stripline. A design method for such a filter is carried out starting from the generalized nonuniform transmission line theory by which a novel closed analytical form for the input reflection coefficient is derived. This closed form allows to obtain straightforwardly the design formulas for the high pass filters. Finally, some applications that show the capability of the new filter here proposed and the fastness of the developed synthesis method are presented.

ISSN:0920-5071    

DOI:10.1163/156939300X00932

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

ISSN:0920-5071    

DOI:10.1163/156939300X00941

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

ISSN:0920-5071    

DOI:10.1163/156939300X00950

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor