基于子阵处理的宽带波束形成的单脉冲测向

Monopulse angle estimation with broadband beamforming based on sub-array processing

现有宽带单脉冲测向方法适用的波束指向角偏差范围小,且基本未考虑分子阵情况,并忽略了匹配滤波对信号的影响。针对这些问题,对宽带线性调频(linear frequency modulation,LFM)信号,提出一种基于子阵内部补相、子阵之间补时延的宽带波束形成的单脉冲测向方法。所提方法通过子阵级处理减少计算复杂度,降低成本,并且分析了匹配滤波对和/差波束的影响,由此推导与实际和/差波束比更为吻合的单脉冲比鉴角曲线表达式,接着提出一种适用波束指向角偏差范围更宽的角度估计方法。与常规单脉冲角度测量方法相比,所提方法具有在低信噪比条件下可测角、测角精确度高,对指向偏差角不敏感,且对大/小型阵列均适用等特点。

The existing wideband monopulse angle estimation methods are applicable for a small range of beam steering angle deviation,and basically do not consider the sub-array situation.The impact of matched filtering on the signal is ignored.To solve these problems,monopulse angle estimation method of wideband beamforming based on the time delay compensation between the phase difference compensation sub-arrays in the sub-array is proposed for linear frequency modulation(LFM)signal.The proposed method reduces computational complexity and costs by performing sub-array level processing,and analyzes the impact of matched filtering on the sum and difference beams.Based on this,a discrimination curve expression that is more consistent with the actual sum and difference beam is derived.Then,an angle estimation method which is suitable for a wider range of beam steering angle deviation is proposed.Compared with the conventional monopulse angle measurement methods,the proposed method stands out due to its high accuracy of goniometric measurement and angle estimation,insensitivity to beam steering angle deviation,and compatibility with both large and small arrays in low signal-to-noise ratio conditions.