摘要
调频步进信号是高空间分辨率雷达常用的宽带雷达信号,该信号综合了线性调频信号和频率步进信号的特点,其步进值Δf和脉冲宽度Tp的乘积可以远远大于1。但该信号进行压缩后具有大的副瓣(包括旁瓣和栅瓣)。有可能导致掩盖小的目标或者被误认为目标,因此必须对其减小。文中对线性加窗、非线性加窗以及非线性步进频率等多种降低调频步进信号副瓣的方法进行了研究;并还提出了按正切函数步进的非线性步进调频信号模型,相比于线性步进调频信号具有更低的副瓣。
Stepped-frequency chirp signal is a wideband radar signal often used in high spatial resolution radar. This signal integrates the characteristics of linear frequency modulated signal （ Chirp） and stepped-frequency rectangle waveform （ SFWF）. The product of the frequency step （△f） and the pulse-duration （ Tp ） can be much larger than one. But this signal has big sidelobes and grating lobes after compression. These lobes may mask small targets or be mistaken as targets, so we must reduce them. This paper studies several methods for reducing both sidelobes and grating lobes of the signal by using linear windowing, nonlinear windowing, and nonlinear stepping. At last, we propose a tangent-shape nonlinear stepped-frequency chirp signal to achieve much lower grating lobes than those of conventional linear stepped-frequcny chirp signal.
出处
《现代雷达》
CSCD
北大核心
2006年第4期45-49,共5页
Modern Radar
