基于虚拟成阵技术的线列阵恒定束宽的波束形成

Constant beamwidth beamforming for linear array based on virtual array technique

为了使基阵对不同的入射频率信号具有相同的空间响应,提出一种均匀线列阵宽带恒定束宽的波束形成新方法.该方法将宽带信号划分为多个子频带,每个频带可以近似为窄带信号.对于不同子频带信号,根据虚拟成阵技术,虚拟出一个新的线列阵,使虚拟阵的阵元间距为此频带信号的半波长,此时,输出的波束宽度为一个只与阵元个数有关、而与频率无关的恒定常数,从而达到恒定束宽的目的.计算机仿真和水池试验验证了此方法的正确性与有效性.

In order to make the array exhibit the same spatial response for different incident frequency signals, a new method for constant broadband beamwidth beamforming for uniform linear array （ULA） was proposed. The broadband signal was divided into multiple sub frequency bands with the proposed method, and each frequency band could be approximated to a narrow band signal. For the different sub frequency band signals, a new ULA was virtualized based on the virtual array technique, and thus, the array element space of virtual array would be half wavelength of corresponding frequency signal. At this point, the output beamwidth was a constant only related to the number of array elements rather than the frequency. There-fore, the constant beamwidth was achieved. The computer simulation and pool experiments verify the correctness and effectiveness of the proposed method.