线性调频信号主瓣不展宽旁瓣抑制方法

摘要

Weighting methods, such as Hamming window, can suppress the peak sidelobe level of matching filter output of Linear Frequency Modulated (LFM) signal, but they also cause obviously mainlobe widening which results in range resolution worsening. Considering requirements of both sidelobe suppression and range resolution, a novel sidelobe suppression method without mainlobe widening is proposed. The amplitude outputs of matching filter and weighting window are firstly normalized, and then compared point by point, finally the minimum value of each point is chosen as the output data. This method fuses both merits of matching filter and weighting processing. The -3 dB mainlobe widening coefficient of the proposed method is only 1 compared with matching filter, and sidelobe suppressing performance is equivalent with the employed weighting window. Simulation results and lake experiment demonstrate the validity of the proposed method.%以汉明窗为代表的加权方法在抑制线性调频信号的匹配滤波输出峰值旁瓣的同时展宽主瓣，致使距离分辨力下降。为兼顾旁瓣抑制和高距离分辨力的需求，该文提出一种新的主瓣不展宽旁瓣抑制方法。该方法首先将匹配滤波和加权处理的输出幅度进行归一化处理，然后逐点进行比较，再取各点对应的最小值作为最终的输出数据。该方法兼取了匹配滤波和加权处理的优点，其-3 dB主瓣展宽系数与匹配滤波相比仅为1，而旁瓣抑制性能和对应的加权处理相当。仿真结果和湖上试验验证了该方法的有效性。