The Surface Basis Functions Combined With The Fast Multipole Method

To realize efficient solution of electromagnetic (EM) scattering from complex target has very practical value for the design of radar system and identify of radar targets. The efficient solver for EM scattering from complex target is more and more important. Hence, it is the important goal of scattering research that finds some efficient and accurate methods.The present paper applies fast multipole method and multilevel fast multipole algorithm based on the curve RWG moment of method to solve scattering from complex target. The present methods can attain less unknowns, less computer memory requirement compared with plane RWG moment of method. The backscattering results of benchmark targets such as big-sphere, NASA almond, ogive ,double ogive and cone-sphere, are given in this paper, they agree very well with the measurement. These numerical results prove the validity and high accuracy of the present methodsAt first, the pivotal techniques of the basic method for solving the integral equation -MOM have been studied. They are: geometrical modeling of the object, plane RWG basis functions.Next, detailed discussion about two aspects of curve RWG basic method: curve RWG basis functions and Singularity, Near Singularity , The research work in the present paper provides a strong means of accurate modeling and efficient analysis of scattering from complex 3-D target especially for complex object with large electrical size. All result compared with measure result is well. The validity of the method and the program has been proved.At last, based on the above research foundation and aimed at resolving the scattering by the complex target with high efficient solution, extensive study of the FMM and MLFMA has been carried out. At first, the principles of FMM and MLFMA have been described. Subsequently, the combination of curve RWG MOM with FMM has been implemented. And modified Lagrange Interpolation Technique has been used.