阵列结构下的低频信号合成方法研究

On method of composing low frequency signals based on array structures

基于高频天线产生低频电磁波信号,实现多波段信号对目标的照射,不仅有可能减小低频天线尺寸,而且可能成为提高雷达目标探测性能的一种途径.本文将多普勒效应与阵列天线结构相结合,基于对阵列中各辐射单元的信号时序、相位和间距等参数的控制,提出了一种在目标区产生低频信号的方法.本文给出了阵列参数的选择原则,介绍了目标位于阵列方向和45°角扫描时的低频信号合成情况,对存在辐射单元间距误差、相位误差、目标偏离预定位置以及等间隔稀疏条件下的合成信号性能进行了分析,并采用峰值旁瓣比和积分旁瓣比来评价合成信号的性能.将频率1 GHz载波信号合成为频率400 MHz信号的仿真分析结果,表明了本文方法的有效性.

Generating low-frequency electromagnetic waves based on high-frequency antenna and illuminating targets with multi-band signals can be an effect way that can not only reduce the physical dimension of a low frequency antenna,but also improve the performance of radar detection.Combining the electromagnetic wave doppler effect principle and the array antenna architecture,a method of generating a low-frequency signal around the illuminated target is proposed based on the controlling of array antenna parameters,including array radiation element signal timing,phase and element spacing.The principles of array parameter design are described.Composite signals are simulated respectively under two typical geometric relationships between targets and array antenna,target located along the array direction and in the direction of 45°scanning angle.The peak sidelobe ratio(PSLR)and integral sidelobe ratio(ISLR)are used to evaluate the quality of the composite signals.Aiming at practical applications,the effects of array element spacing error,phase error and target location error on the composite signal are simulated and analyzed.Under the condition of sparse uniform array,the influence of the radiation element spacing on the composite signal is analyzed.The simulation results show that the harmonic components of the composite signal increase with the radiating element spacing error and phase error growing.