宽带数字波束形成雷达的高精度延时补偿新方法

A New Method of High Precision Delay Compensation for Wideband Digital Beamforming Radar

采用宽带信号的相控阵雷达可获得很高的距离分辨率,将广泛用于下一代多功能雷达系统中。传统窄带相控阵体制很难解决宽带相控阵雷达的空间色散和孔径渡越问题,尤其在宽带相控阵雷达做宽角扫描时,必须在阵元或子阵间使用精确的时延补偿。文中提出了一种实现高精度宽带相控阵延时补偿的新方法。该方法采用一种有效的可变分数延时滤波器新结构,即泰勒结构。该结构相对于传统的Farrow结构的主要优点是减少了乘法器和加法器的数量,降低了可变延时滤波器系数的计算难度。试验证明,新的方法能实现精确的宽带波束扫描,可应用于接收和发射数字波束形成的工程实现。

Wideband phased array radar has high range resolution and it will be widely used in the next generation of multi-function radar system. The narrowband phased array radar uses phase shifting to steer the beam,which is difficult to solve the problem of the spatial dispersion and the transition time of a large aperture. Thus in order to scan the beam off bore-sight precisely in a wideband phased array radar system,time delay compensation must be applied. This paper proposes a novel technique for wideband time delay compensation implementation,which makes use of an effective variable fractional delay filter based on Taylor structure. Compared with the traditional Farrow structure,the number of multipliers and adders as well as the computational complexity has been highly reduced whereas the compensation accuracy has been maintained. Simulation results validate the effectiveness of the presented method and good performance has been shown in terms of accurate beam scanning over wideband.