A new set of travelling-standing-wave (TSW) basis functions are proposed for curved triangular patch in this paper. This kind of bases is not only able to describe the standing component of induced surface current but also able to simulate the phase variation of induced current accurately. The authors used these basis functions to discrete surface integral equation (SIE) with a series of coarse meshes (even larger than 2λ) to calculate the electromagnetic (EM) scattering from the perfect electric conductor (PEC) targets with method of moment (MoM). Numerical experiments indicate that the MoM-TSW scheme even has more advantages than the MLFMA-CRWG scheme in the aspects of computational efficiency and memory storage.

In this article, a new set of high-order vector basis functions with phase descriptions, which are named traveling-standing-wave basis functions, is proposed for electromagnetic simulation with triangular patches. Such bases have an excellent capacity of describing the complicated standing-wave distribution and the rapid phase variation of the induced surface current. These basis functions were defined on electrically large patches so that the number of unknowns is lowered tremendously. A fast algorithm, such as the multilevel fast multiple algorithm, can easily be combined with the proposed basis functions to further reduce the computational complexity of numerical calculation. More importantly, the targets can be any convex, concave structures with any shape. Numerical experiments have demonstrated that reliable accuracy with the multilevel fast multiple algorithm-traveling-standing-wave scheme can be obtained even though the number of unknowns is reduced dramatically. Another benefit is that a fast convergence rate can be commonly achieved.

No abstract

The integral equation method have been used to set up the physical model of the wave transmission in the beam waveguide. The Mode Matching method has been used to describe the matching situation at the exciting aperture. The Multilevel Fast Multipole Algorithm (MLFMA) has been used to accelerate the calculation. The Phase Extraction (PE) basis function is used to discrete the electric current. It has been demonstrated that the method proposed by this paper is able to provide the accurate solution for the excitation, propagation and radiation problems of the beam waveguide with arbitrary shape and electrically large size efficiently. Index Terms -Beam waveguide, integral equations, Multilevel Fast Multipole Algorithm, PE basis function.

No abstract