Search

This article proposes a new kind of microstrip reflectarray antenna, of which the polarization could be reconfigured among all the polarization states instead of some fixed states in a dual-or multi-polarized antenna. The mechanism for polarized variability is so simple that only mechanical rotation is needed. Theoretical analysis shows that the reflected polarization covers all states and that the dual-or multi-layered unit structure sandwiched with air-gaps can broaden the bandwidth efficiently. Moreover, it is demonstrated that adopting more elements can enhance antenna gain. With these advantageous features, this kind of antenna has the potential significance for engineering applications in radar, communication, etc. In this article, a complete theoretical analysis as well as a specific design sample is given to verify this method.

A one-dimensional modified integral equation for electromagnetic scattering from a metallic concentric disc-ring structure is derived by using Fourier expansion and separating the contribution of charge density from conventional EFIE. In the case of normal incidence, the derived equation is very simple and easy to be solved numerically regardless of the electric dimension of the structure. The comparison between the data of RCS of a disc by using this method and analytical method shows the effectiveness of this approach. Numerical results are also given for current distributions and the scattered fields for a disc-ring structure.

In this paper, the convergence rate at matching points of collocation technique is shown to beO(h 2), that is just the same as the global convergence rate of Galerkin’s method with triangular pulses as basis and weighting functions. A numerical example to verify the conclusion is given.

Based on the second kind of Green’s identity, a boundary integral equation for arbitrary cross-section waveguide is transformed to a system of linear homogeneous algebraic equations by means of expansion of boundary bases and by using the eigen functions of a fictitious regular boundary as weighting functions, which corresponds to less algebraic equations than BEM and simpler coefficients than the modified BEM. The numerical results for some typical metallic waveguides are given by using the method of eigen-weighted boundary integral equation, and they are accurate enough with fast convergence.

A collocation method with multipoint weighting is presented in this paper. It converges as rapidly as the Galerkin method but needs less computation effort. By means of the technique with Gauss points (superconvergence points) as the collocating points, dipole and dipole array are analyzed, and the numerical results are in good agreement with those given in relative references.

The global convergence rate of the method of moments for EM boundary value problems with piecewise polynomial basis functions of degree k and piecewise polynomial weighting functions of degree n(n >