Solution and Design Technique for Beam Waveguide Antenna System by Using a Parallel Hybrid-Dimensional FDTD Method

This letter presents a novel technique to accurately solve the radiation problems of a beam waveguide (BWG) antenna system aiming to achieve high gain and low sidelobe level (SLL). In order to rapidly obtain the radiation field of the antenna system, a hybrid method using three-dimensional (3-D) nonuniform meshing finite-difference time domain (FDTD) with symmetric boundary condition and body-of-revolution FDTD has been employed. In this method, a parallel algorithm with MPI is applied to enhance computational efficiency, and several approaches are adopted to reduce the errors of simulation. Numerical examinations demonstrate that both the computer memory and run time can be greatly saved by performing this 3-D–2-D hybrid FDTD simulation instead of a complete 3-D one. Furthermore, the accuracy of this method has been validated with a scaled model. Finally, the hybrid method combined with an optimization algorithm has been applied to design an X-band BWG antenna system. Numerical results show a 2.02-dB gain improvement and a 3.46-dB SLL reduction after optimization.