结合傅立叶变换的差分进化算法在阵列波束展宽中的应用

Application of Differential Evolution Algorithm Combined Fourier Transform on Array Beam Broadening

提出了一种新型阵列波束展宽的方法,使用差分进化算法结合傅立叶级数变换的初值对阵列波束进行展宽设计。与普通傅立叶级数变换法展宽波束相比,该方法获得主波束范围内的平坦度更好,且能得到更低的副瓣电平。推荐的方法还能避免传统差分进化算法收敛速度慢、易陷入局部最优的问题。文中使用该方法对一个21元的一维直线阵进行波束展宽优化设计。在等幅同相情况下,直线阵的3dB波束宽度为4.02o,使用推荐方法设计后,3dB波束宽度扩展到19.6o,主波束范围内的平坦度为0.21dB,证实了该方法的可行性。

A new method of array beam broadening is presented in this paper, which uses the differential evolution algorithm combined with Fourier series transform to broaden array beam. Compared with the traditional Fourier series transform, this method can obtain better gain flatness within the range of main beam and lower side lobe level. The presented method can also avoid the problems of having slow convergence speed and easily falling into local optima. The presented method is used to broaden the main beam of a 21 element linear array in this paper. When the elements are excited with the same amplitude and the same phase, the array has a 3-dB beamwidth of 4.02. After using the presented method, the array has a 3-dB beamwidth of 19.6 and the gain flatness within the range of the main beam is 0.21 dB, which validate this method.