在噪声雷达中,传统相关处理方法的距离旁瓣受到时宽带宽积的限制,在有限相关处理时间内得到的距离旁瓣较高,会造成微弱目标被强目标、杂波旁瓣淹没的现象。提出一种基于抽取最小均方(Least Mean Square,LMS)滤波的噪声雷达旁瓣抑制方法,将LMS滤波器的系数作为距离压缩结果,从而获取较低的距离旁瓣。对该方法的性能进行了理论分析,并通过数字仿真验证了算法的有效性和理论分析的正确性。 相似文献
The effect of Co, Pd and Pt ultrathin films on the kinetics of the formation of Ni-silicide by reactive diffusion is investigated. 50 nm Ni/1 nm X/ 50 nm Ni (X?=?Co, Pd, Pt) deposited on Si(100) substrates are studied using in-situ and ex-situ measurements by X-ray diffraction (XRD). The presence of Co, Pd or Pt thin films in between the Ni layers delays the formation of the metal rich phase compared to the pure Ni/Si system and thus these films act as diffusion barriers. A simultaneous silicide formation (δ-Ni2Si and NiSi phases) different from the classic sequential formation is found during the consumption of the top Ni layer for which Ni has to diffuse through the barrier. A model for the simultaneous growth in the presence of a barrier is developed, and simulation of the kinetics measured by XRD is used to determine the permeability of the different barriers. Atom probe tomography (APT) of the Ni/Pd/Ni system shows that the Pd layer is located between the Ni top layer and δ-Ni2Si during the silicide growth, in accordance with a silicide formation controlled by Ni diffusion through the Pd layer. The effect of the barrier on the silicide formation and properties is discussed.