步进频信号波束形成指向偏差与通道误差影响分析

Analysis of Pointing Bias and Channel Error in Digital Beamforming of Stepped Frequency Signal

步进频信号波束形成时存在着波束指向偏差和通道间幅相误差,并且对各个步进频脉冲是不同的,即对各步进频脉冲进行了不同的幅相调制。文中首先从理论上分析了这种调制对距离高分辨处理的影响,指出波束指向偏差会使目标距离像发生偏移,但是偏移量很小,通常可以忽略,而通道误差的影响主要是抬高了距离高分辨处理的副瓣电平。然后,对波束指向偏差和通道误差的影响进行了仿真,验证了上述结论。

The pointing bias of beam and the amplitude&phase errors between channels exist when digital beamforming is performed for the stepped frequency signal.The bias and error are different for each stepped frequency pulse,because each pulse is modulated by different amplitude&phase error.Firstly,the effect of the modulation error on the following range high resolution processing is theoretically analyzed in this paper.It is found that the pointing bias of beam can move range image of target,but the movement is small and can be neglected,and the main effect of channel error is to raise the sidelobes of the range high resolution processing.Finally,the effect of the pointing bias and the amplitude&phase errors is simulated separately and demonstrates the above conclusions.