融合插值点优化的多项式结构宽带波束形成器设计方法*

多项式结构设计方法是主瓣指向可调宽带波束形成器设计的一类重要方法。多项式结构的阶数是有限的，导致主瓣实际指向与期望指向之间存在偏差，因而影响了波束形成器的指向性指数。针对这一问题，该文提出了一种基于插值点优化的多项式结构宽带波束形成器设计方法。首先，引入多项式结构插值点处阵列响应的空间导数约束，以减小主瓣指向偏差；进而利用粒子群优化算法对多项式结构中的插值点进行优化，以充分利用插值点位置提供的自由度进一步提升多项式结构宽带波束形成器的性能。优化设计结果表明，与现有设计方法相比，该文提出的方法不仅降低了主瓣的指向偏差，同时也提高了指向性指数，有效改善了多项式结构宽带波束形成器的性能。

Design of polynomial broadband beamformers based on interpolation point optimization

Polynomial structure based design is one of the important methods in the design of steerable broadband beamformers. The order of polynomial structure is finite, it often leads to the deviation between the actual and the desired mainlobe orientation, thus affecting the directivity index of the beamformer. To address this problem, a polynomial broadband beamformers design method based on interpolation point optimization is proposed in this paper. First, the spatial derivative constraint of the array response at the interpolation point of the polynomial structure is introduced, and then the interpolation point in the polynomial structure is optimized using a particle swarm optimization algorithm to take full advantage of freedom provided by the interpolation point position to improve the design performance of the polynomial broadband beamformers. The optimized design results show that the proposed method not only reduces the orientation deviation of the mainlobe but also improves the directivity index compared with the existing design methods, which effectively improves the performance of the polynomial broadband beamformers.