宽带恒定束宽波束形成器的设计与实现

本文提出了一种设计宽带恒定束宽波束形成器的方法，这对应用于海底探测和分类问题的声纳系统来说十分重要，对于给定频带宽度的信号，选择一定数量的频率点来表达其频率响应，对于一个给定的频点，可以通过现有方法导出满足恒定宽要求的加权矢量，例如对于一个线阵列，可用切比雪夫多项多得到其加权矢量，因此对于一个具有Ｎ个阵元的宽带阵，如果选择Ｍ个频率点，可以得到一个ＮＭ的加权矩阵，这个矩阵的每一行代表一个阵元的频率响

Beamformer for broadband constant beamwidth through FIR and DSP implementation

The paper presents a method to design a beamformer for broadband constant beamwidth. Such a beamformer is important in sonar systems for sea bottom observa- tion and classification applications. For a given frequency band, a number of frequency points are chosen to represent the response. For each frequency point a beamforming weighting vector can be deduced to satisfy a given beamwidth requirement by existing methods, for example the Chebyshev shielding coefficients can be deduced for a linear array. Therefore, for a broadband array of N elements and for M chosen frequency points, a N'M weighting matrix in which each row represents a frequency response of an array element, which can be satisfied by a FIR filter designed by the model-reference adaptive technique. The sum of outputs from a bank of N FIR filters provides a beamformed output and so it is very handy to be implemented by DSP hardware. A design example shows that the results are satisfactory.