The Research On FDTD-based Non-uniform And Conformal Grid

With the progress of modern science and technology, the applicative range of electromagnetic field is becoming wider and wider, and the development of the electromagnetism theory is more and more quickly. Meanwhile, the rapid development of computer technology contributes greatly to the development of computational electromagnetics. The finite difference time domain(FDTD) method, with its unique advantages and performances, is catching attention and being applied in more and more fields, and the electromagnetic simulation software based on FDTD algorithm is developing effectively.The main work of this paper is to study the FDTD-based non-uniform as well as conformal grid technology. The specific formula of non-uniform algorithm are derived, and the conformal grid is studied. The simulation module data structure is constructed via MATLB GUI so as to achieve the function of visualization for both the data input interface and the simulation results. By MATLAB GUI development system, the function modules of the electromagnetic simulation are designed which can be seen as a simple electromagnetic simulation software.This paper firstly reviews the FDTD algorithm, including the general difference equations of FDTD method, the numerical dispersion, the stability conditions and absorbing boundary conditions, etc. This is followed by the deduction of the differential equations for non-uniform grid, and a study on the stability, numerical dispersion and absorbing boundary conditions of non-uniform grid. And then the ideal conductor conformal grid technology and medium surface conformal grid technology are introduced. Finally, this paper introduces the GUI function of MATLAB, and develops electromagnetic simulation software by GUI programming. The feasibility and reliability of the software are illustrated by the near-field simulation analysis of the target objects as well as the subdivision of objects with different shapes on the grid.