New boundary integral equations are proposed for two-port slab waveguides which satisfy single mode condition. The boundary integral equations are combined with the orthogonality of guided mode and non-guided field. They are solved by the standard boundary element method with no use of mode expansion technique. Reflection and transmission coefficients of guided mode are directly determined by the boundary element method. To validate the proposed method, step waveguides for TE wave incidence and triangular rib waveguides for TM wave incidence are investigated by numerical calculations.

The main purpose of this paper is to apply the boundary integral equation (BIE) method to the analysis of spoof localized surface plasmons (spoof LSPs) excited in a perfectly conducting cylinder with longitudinal corrugations. Frequency domain BIE schemes based on electric field integral equation (EFIE), magnetic field integral equation (MFIE) and combined field integral equation (CFIE) formulations are used to solve two-dimensional electromagnetic (EM) problems of scattering from the cylinder illuminated by a transverse electric plane wave. In this approach effects of spoof LSPs are included in the secondary surface current and charge densities resulting from the interaction between the plane wave and the cylinder. Numerical results obtained with the BIE schemes are validated by comparison with that of a recently proposed modal solution based on the metamaterial approximation.

We show examples of accurate computer-aided design of power coupling between two dielectric slab waveguides of finite length by using the boundary-element method (BEM) based on guided-mode extracted integral equations (GMEIE's). The integral equations derived in this paper can be solved by the conventional BEM. Various properties in numerical calculations of GMEIE's are examined. The reflection and coupling coefficients of the guided wave as well as the scattering power are calculated numerically for the case of incidence TM guided-mode. The presented results are checked by the energy conservation law and reciprocity theorem. The results show that it is possible to design an optimum coupling between two dielectric slab waveguides by using the BEM based on GMEIE's.

In this paper, we present an analysis of the microstrip lines whose strip conductors are of various cross-sections, such as rectangular cross-section, triangle cross-section, and half-cycle cross-section. The method employed is the boundary integral equation method (BIEM). Numerical results for these microstrip lines demonstrate various shape effects of the strip conductor on the characteristics of lines. The processing technique on the convergence of the Green's function is also described.

In this paper, we present an analysis of microstrip line with a trapezoidal dielectric ridge in multilayered media. The method employed in this characterization is called partial-boundary element method (p-BEM) which provides an efficient technique to the analysis of the structures with multilayered media. To improve the convergence of the Green's function used in the analysis with the P-BEM, we employ a technique based on a combination of the Fourier series expansion and the method of images. Treatment on convergence for the boundary integrals is also described. After this treatment, it requires typically one tenth or one hundredth of Fourier terms to obtain the same accuracy compared with the original Green's function. Numerical results are presented for two microstrip lines that have a trapezoidal dielectric ridge placed on a one-layered substrate and a two-layered substrate. These numerical results demonstrate the effects on the characteristics of the microstrip line due to the existence of the dielectric ridge as well as the second layer between the ridge and the fundamental substrate.

In the paper a problem of wave scattering from a local penetrable inhomogeneity inside a planar dielectric waveguide is studied. The surface potentials method is applied for the problem and the set of systems of BIE is obtained and analyzed from the view-point of their numerical solution. The effective numerical algorithm based on the Nyström method is proposed. The equations for a scattering diagram and mode conversion coefficients are derived.

Numerical analysis of the electromagnetic radiation from conducting surface structures is concerned. The method of moments is discussed with the surface-patch modeling in which the surface quantities, i.e. the current, charge and impedance are directly introduced and with the wire-grid modeling in which the surface quantities are approximated by the filamentary traces. The crucial element to a numerical advantage of the wire-grid modeling lies in the simplicity of its mathematical involvements that should be traded for the uncertainties in the construction of the model. The surface-patch techniques are generally not only clear and straightforward but also more reliable than the wire-grid modeling for the computation of the surface quantities. In this work, we bring about a comparative discussion of the two approaches while the analysis of a built-in planar antenna is reported. For the purpose of the comparison, the same electric field integral equation and the Galerkin's procedure with the linear expansion/testing functions are used for both the wire-grid and surface-patch modeling.