共查询到20条相似文献,搜索用时 15 毫秒
1.
Te-Kao Wu 《International Journal of Infrared and Millimeter Waves》1994,15(3):567-577
In this paper, a solution is developed to calculate the electric field at one point in space due to an electric dipole exciting an arbitrarily shaped dielectric body of revolution (BOR). Specifically, the electric field is determined from the solution of coupled surface integral equations (SIE) for the induced surface electric and magnetic currents on the dielectric body excited by an elementary electric current dipole source. Both the interior and exterior fields to the dielectric BOR may be accurately evaluated via this approach. For a highly lossy dielectric body, the numerical Green's function is also obtainable from an approximate integral equation (AIE) based on a surface boundary condition. If this equation is solved by the method of moments, significant numerical efficiency over SIE is realized. Numerical results obtained by both SIE and AIE approaches agree with the exact solution for the special case of a dielectric sphere. With this numerical Green's function, the complicated radiation and scattering problems in the presence of an arbitrarily shaped dielectric BOR are readily solvable by the method of moments. 相似文献
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The waveguide propagation of a monochromatic electromagnetic wave in a multilayer smoothly-irregular integrated dielectric structure has been studied under natural physical and mathematical assumptions. Approximate solution of the vector electrodynamic problem satisfying the condition of smoothly varying shape of the structure is found using the Kantorovich method of the partial separation of variables, since the conventional method of separating variables, which is usually employed for regular waveguides, in the given case is inapplicable. Using the obtained solution, it is possible to describe analytically the fields of smoothly deforming modes of a dielectric waveguide, their interrelation, and the dispersion relations between the distribution of the phase slowing coefficient and the local inclination of layers in the structure under consideration. The proposed method can also be used, in a quite broad range of wavelengths, for an analysis of analogous waveguide structures made of both dielectric and magnetic materials. 相似文献
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Hai-Long Wang Qun Wu Le-Wei Li Jian Wu 《International Journal of Infrared and Millimeter Waves》2008,29(4):373-384
The electric field properties of the electric line source radiation in the presence of a lossy metamaterial covered dielectric
cylinder are investigated. Firstly, the electromagnetic model configuration is given. The exact solution of the electromagnetic
is presented. Secondly, the near field and the far field properties are investigated according to the electromagnetic and
geometrical parameters. The different “focus” phenomenon, the directivities and the normalized radiation resistance are discussed
and important conclusions are obtained. During all the numerical computation, the lossy conventional material covered dielectric
cylinder is utilized as the reference. 相似文献
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电偶极子位于均匀介质球中时球外电场的研究 总被引:1,自引:0,他引:1
采用分离变量法求解了电偶极子位于均匀介质球中时复连通域的拉普拉斯方程和泊松方程,求出了球内外两种不同介质的电势分布和球面上的极化电荷分布;通过求解二阶非线性微分方程得到了球外的电场线函数;利用计算软件Math-ematica 5.0,作出了相应的相互正交的等势线簇图形和电场线簇图形,并且进行了必要的讨论. 相似文献
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M. B. Kanevskii 《Radiophysics and Quantum Electronics》1966,9(5):508-512
A calculation is given for the average field produced by a narrow-beam source in a tropospheric waveguide close to the sea. The source is taken to be below the inversion layer. The roughness of sea is taken into account by introducing an effective dielectric constant derived from the average reflection coefficient. Curves are given showing the variation of the average field in the waveguide as a function of height at different distances from the source.Izvestiya VUZ. Radiofizika, Vol. 9, No. 5, pp. 867–875, 1966 相似文献
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Plasmonic waveguides and conventional dielectric waveguides have favorable characteristics in photonic integrated circuits. Typically, plasmonic waveguides can provide subwavelength mode confinement, as shown by their small mode area, whereas conventional dielectric waveguides guide light with low loss, as shown by their long propagation length. However, the simultaneous achievement of subwavelength mode confinement and low-loss propagation remains limited. In this paper, we propose a novel design of an alldielectric bowtie waveguide, which simultaneously exhibits both subwavelength mode confinement and theoretically lossless propagation. Contrary to traditional dielectric waveguides, where the guidance of light is based on total internal reflection, the principle of the all-dielectric bowtie waveguide is based on the combined use of the conservation of the normal component of the electric displacement and the tangential component of the electric field, such that it can achieve a mode area comparable to its plasmonic counterparts. The mode distribution in the all-dielectric bowtie waveguide can be precisely controlled by manipulating the geometric design. Our work shows that it is possible to achieve extreme light confinement by using dielectric instead of lossy metals. 相似文献
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In this paper, we study the influence of periodic inhomogeneity of the surface impedance on the field of an electric dipole located in a waveguide. The inhomogeneity period is assumed to be close to the wavelength of the source in free space. An analytical representation for the field in the waveguide channel is obtained. We estimate the inhomogeneity period for which a mode of a given number is excited most efficiently. 相似文献
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本文提出一种基于全介电微散射体的散射阵列结构逆向设计方法,用以实现散射电场强度整形.该方法基于空域傅里叶变换与角谱变换,从给定目标区域处期望实现的散射场强分布出发,逆向求得所需的感应源,再利用电磁感应源理论,逆向设计微散射体阵列,且只需通过解析计算便能够快速地求取出微散射体阵列的电磁参数值分布.基于提出的逆向设计方法,文中提供了三维情况下的具体算例,实现了给定方形面目标区域的散射场强整形.理论计算结果与全波仿真结果符合良好,表明本文提出的逆向设计方法具有可行性与有效性. 相似文献
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This paper investigates analytically the electric field distribution of graded spherical core-shell metamaterials, whose permittivity is given by the graded Drude model. Under the illumination of a uniform incident optical field, the obtained results show that the electrical field distribution in the shell region is controllable and the electric field peak’s position inside the spherical shell can be confined in a desired position by varying the frequency of the optical field as well as the parameters of the graded dielectric profiles. It has also offered an intuitive explanation for controlling the local electric field by graded metamaterials. 相似文献
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Based on classical electromagnetic theory, characteristics of guided modes in a rectangular waveguide filled with a pair of single-negative layers are studied. The results show that only surface waves of TE mode can propagate in this peculiar waveguide, no TM mode in any forms can propagate in it. In addition, TE waveguide modes will be affected by permeability ratio μ1/μ2 and dielectric layer thickness ratio P. Finally, from the electric field distribution of TE mode, we find the amplitude and location of the electric field can be adjusted by changing the thickness ratio P. 相似文献
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O. V. Solov'ev 《Radiophysics and Quantum Electronics》1992,35(6-7):368-373
The author investigates effect on the field of a point source in a plane impedance waveguide of an irregularity in the form of spherical surface that projects from (or is embedded into) the plane of the, ionospheric wall of the waveguide. In a scalar approximation, the problem is reduced to a two-dimensional integral equation over the surface of the irregularity. A solution is constructed by successive approximations, for which the solution of the problem for a regular impedance waveguide is used as the initial approximation. Numerical results are given for estimation of the effect of a local ionospheric irregularity on the field of an electric dipole in the earth-ionosphere waveguide.St. Petersburg State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 35, No. 6/7, pp. 569–578, June–July, 1992. 相似文献
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N. K. Uzunoglu C. N. Capsalis S. E. Halios 《International Journal of Infrared and Millimeter Waves》1986,7(11):1715-1727
The diffraction of guided waves by the end face of a dielectric slab waveguide short circuited with a finite conductive strip is analyzed. An integral equation technique is employed to formulate the corresponding boundary problem. The unknown term in this integral equations is the electric field E(x) on the terminal plane of the waveguide. The homogeneous term is determined from the incident guided wave. A method of moments technique is employed to compute approximately the electric field E(x) by using Laguerre functions as describing and testing functions. The reflection coefficients of the guided waves are computed by using the approximate expression of the E(x) field. Numerical results are given for several guide and conductor plate dimensions. 相似文献
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Marian H. Rose 《International Journal of Infrared and Millimeter Waves》1986,7(2):197-235
A previously developed variational technique for finding the approximate solution to the electromagnetic field inside waveguides of varying shapes and containing non-uniform dielectric and magnetic materials is applied to the specific case of an axisymmetric waveguide containing three layers of different dielectric materials. The magnetic permeability is taken equal to unity. The method enables the problem to be reduced to a two point boundary value problem for a pair of second order, linear, ordinary differential equations. The values of the reflection and transmission coefficients obtained by this method are in good agreement with those derived from solving the partial differential equations for the field. 相似文献
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V. K. Belyaev 《Technical Physics》2005,50(6):673-679
The free charge steady-state distribution over the insulator surface that arises in a strong electric field in a vacuum can
be found by solving the boundary-value problem for the electrostatic field strength if the angle between the field vector
and vacuum-insulator interface is given. A general solution to this boundary-value problem is derived for the case of an in-plane
field and rectilinear interfaces. Laws of charge and field formation that follow from the solution obtained are considered.
Formulas for the electric field strength and charge density in terms of elementary functions are obtained for a number of
particular cases. Power-type expressions for the electric field and a critical angle between the electrode and insulator surface
that describe the field behavior and charge distribution near the vacuum-insulator-electrode contact are derived. 相似文献