Higher Order Basis Functions Based On The Eb When Domain Finite Element Applications

This paper studies high order vector basis functions (1.5 order basis function and 2.5 order basis function) in the finite element time domain (FETD) method.In the FETD method. the traditional vector basis functions along the edge direction is constant and along the normal direction of the edge is linear interpolation, which limits interpolation accuracy of the actual electromagnetic field simulation using traditional method. Based on the problem, the paper uses high order vector basis functions and has a main research on the use of 1.5 and 2.5 basis functions in the FETD based Maxwell's equations. Then take resonance cavity, waveguide and microstrip circuit for example to simulate. The numerical simulation results show that this method using high order vector basis functions can reduce unknowns in the case of discretization by meshes of large size when accuracy is the same as lower order vector basis functions. The results also show that the solution precision can be improved in the case of the same unknowns as lower order vector basis functions.When regular tetrahedron simulates surface bend structure, the simulation precision is low. So the paper combines high order vector basis functions with irregular tetrahedron. In the case of discretization by meshes of large size, both the simulation precision and the solution precision can be improved.The paper combines high order vector basis functions with H-matrix to analyze waveguide and microstrip circuits. The results clearly show that memory complexity is O(N log N) and time complexity is O(N log2 N). This property gives it a big advantage over other direct solvers.