Study Of The Higher-Order Moment Method

Although lower-order moment method as RWG is widely used in the computational electromagnetics, its application in electrically large problems is restricted by its small element or patch. The higher-order moment method established by foreign specialists could overcome this shortcoming. However few Chinese have paid attention to it.This paper not only presents the elementary theory of the higher-order moment method, but also makes us familiar with its merits and drawbacks by solving a simple differential equation, the radiation of a half-wave dipole and the scattering of a PEC square plate., thus laying a solid foundation for further research.Firstly, this paper presents the elementary theories of the lower-order moment method, involving the wire antenna and RWG. Then the solution of a typical differential equation proves that the higher-order moment method has a much better convergence rate. Finally, the higher-order moment method is applied to analyze a half-wave dipole and a PEC square plate, where a formula for calculating the integration with singularities is presented. And the results indicate that higher-order moment method may have a much higher degree of accuracy though the patch is larger in electrical scale.As an effective technique for dealing with the problems where patches must be very small in the general moment methods, the higher-order moment method is of much significance in practical application.