Analysis of Large Slotted-Waveguide Antenna Arrays Using the Parallel DDA-FE-BI-MLFMA

An efficient analyzing approach is presented for large slotted-waveguide antenna arrays by using hybrid finite element-boundary integral-multilevel fast multipole algorithm (FE-BI-MLFMA) in this paper. A simple computation model for slotted-waveguide antenna is presented by using thin current probe excitation and perfectly matched layer (PML) absorber. Since each slotted-waveguide antenna can be considered as a single sub-domain, the domain decomposition algorithm (DDA) can be applied to FE-BI-MLFMA to greatly reduce the computation resources and achieve high efficiency. This DDA-FE-BI-MLMFA is parallelized to further strength its capability. The comparisons of the computed radiation patterns with measured data and results from the commercial software show that our method has good accuracy for slotted-waveguide array. Then the influence of mutual coupling between adjacent slotted-waveguides is studied. To demonstrate capability of the presented method, a carefully designed large X-band slotted-waveguide antenna array containing eighteen waveguides with Taylor amplitude and inverse phase excitation distribution are analyzed in the paper.