The Fast And Accurate RCS Computation Of Antenna Array

In this thesis, periodic boundary condition is applied to total-and scattered-field decomposition finite element method (TSFD-FEM) for the scattering analysis of antenna array. Firstly, with Mur absorbing boundary condition, the equivenlent functional is presented. Volumetric excitation method is employed to impress the incident field which can improve the precision greatly. To verify the accuracy of TSFD-FEM, the radar cross sections (RCS) of microstrip antenna and other complex dielectric objects are calculated. And then, the input channel of antenna is modeled in TSFD-FEM. For further accurate analysis of the antenna array, according to the Floquet theory, periodic boundary condition is applied, so that the mutual coupling is reasonably simulated. The computational area is discreted with Hypermesh softwear to obtain the symmetrical grids on the periodic boundarys.The combination of Sub-Entire Domain (SED) method and FEM (SED-MoM/FEM) is modified with the periodic TSFD-FEM mentioned above, and PSED/FEM hybrid method is proposed for the electromagnetic scattering analysis of antenna arrays. The RCSs of one-dimensional antenna arrays and other object arrays are calculated, which verify the accuracy of PSED/FEM hybrid method. The closed face of ouput boundary can be set either in total-field area or scattered-field, but the RCS obtained from scattered field is more accurate, which is verified with numerical results presented in the dissertation.To achieve higher efficiency, PSED/FEM algorithm is accelerated by parallel technology based on OpenMP. The blocks of matrix solution in TSFD-FEM and impedance matrix filling in SED-MoM are accelerated with OpenMP on multi-CPU computers. Numerical results indicate that the maximum speed-up ratios of TSFD-FEM and SED-MoM can achieve 4.51 and 6.72 respectively on 8CPU work station, and the computational time is reduced significantly.