反隐身是现代雷达防御系统的重要技术指标，当前微波波段的反隐身雷达系统都以平面波为基础，大多在算法层面上提高检测前信噪比，效果有限。近年来，轨道角动量（OAM）涡旋电磁波因具有不同于传统平面波的空间相位特性，受到了研究人员的关注，但是微波波段OAM波的目标散射特性未知，是否能够通过OAM电磁波提高隐身目标的检测前信噪比成为重要疑问。本文研究了OAM波对复杂目标的散射特性，提出了旋转天线OAM波产生算法，并应用于雷达探测与方位成像中，提出了多基地OAM波的雷达通信一体化方法和二次雷达（SSR）方案。首先，基于理论分析和微波暗室实验，提出了利用OAM电磁波空间相位梯度特性的雷达截面积（RCS）分集方法。进一步给出了在OAM电磁波照射下的RCS定义，并计算了几种“简单”复杂目标的RCS值；在微波暗室中对目标RCS值进行测量，与单独采用平面波相对比，实验中可获得7dB以上的RCS分集增益，说明可以通过分集合并方法提高对弱RCS值目标的检测概率。其次，针对隐身目标RCS分集所需高阶OAM模式数产生困难的问题，提出旋转天线OAM波的产生方法。受四维天线系统中将时间维度引入天线设计的启发，提出基于旋转天线的等效OAM信号合成算法，在接收端产生高阶等效OAM信号。仿真结果表明，与传统方法相比，旋转天线OAM波的模式数可以获得大幅提升，通过分集技术可以获得RCS增益。进一步，提出旋转天线OAM波的方位成像算法，用等效的高阶模式数来提高OAM成像的方位分辨率。实验中，在模式数为90时获得了2°方位分辨率，达到OAM成像分辨率的理论界。其三，为了在多基地雷达探测系统中进一步提高隐身目标的检测前信噪比，研究了OAM波在多基地下RCS分集特性，提出雷达通信一体化系统架构和基于线性调频最小频移键控信号的脉冲对处理方法，通过多信号源获得RCS分集增益，并进一步明确了基于旋转天线OAM的多基地系统设计方法；对空中合作目标，利用OAM波全向波束特性，提出了基于OAM波的二次雷达系统以取代传统定向波束和机械旋转结构，使其方位测量能力不依赖于机械转动。最后，搭建了旋转天线OAM雷达硬件演示验证系统，验证了旋转天线OAM波方法的正确性和有效性。

Anti-stealth capbility is essential to modern radar defense system. Currently, anti-stealth radar system in the microwave band is based on plane wave, and most methods are based on signal processing algorithms. Recently, the progress on physical level of electromagnetic wave provides new theory for the anti-stealth technology. The vortex electromagnetic wave with orbital angular momentum (OAM) has spatial phase gradient different from that of conventional plane waves, thus it attracts attention from many researchers. However, the target scattering characteristic of the OAM wave in microwave band is unknown, and the generation method of the high-order OAM mode number that ensures the adequate spatial phase gradient is unknown. To solve the above problems, this dissertation studies the scattering characteristics of OAM waves for complex targets, proposes an equivalent high-order OAM wave generation method, and studies the application of OAM in multistatic radar system.Firstly, based on theoretical analysis and microwave chamber experiments, a radar cross section (RCS) diversity method using OAM wave spatial phase gradient is proposed. This specific research work gives the RCS definition under the OAM wave illumination, and calculates the corresponding RCS values of several typical complex targets. The target RCS values are measured in the microwavechamber. By RCS diversity and combining method, the target RCS value can be improved under different OAM waves compared with the only plane wave. The RCS value of the target is measured in the microwave anechoic chamber, and more than 7dB RCS diversity gain can be obtained in the experiment compared with the plane wave, indicating that the OAM wave can improve the detection capbility towards the weak target through diversity combination.Secondly, for the problem of generating high-order OAM modes, an equivalent OAM signal generation method based on rotating antenna is proposed. Using the linear superposition of electromagnetic waves, the dimension of time is introduced into the OAM signal synthesis to form a four-dimensional antenna. Based on the system, an equivalent OAM signal synthesis algorithm is proposed to generate high-order equivalent OAM signals at the receiving end. Simulation results show that the mode number of the OAM wave of the rotating antenna can be significantly improved compared with traditional OAM wave generation methods, and the RCS gain can be obtained through combining method. Furthermore, the azimuth imaging algorithm for OAM wave of rotating antenna is proposed, and the equivalent high order mode number is used to improve the azimuth resolution of OAM imaging. Through the experiment, when the mode number reaches 90, a 2° azimuth resolution can be obtained, reaching the OAM imaging resolution limit.Thirdly, the OAM wave application in multistatic radar system is studied. In order to improve the signal to noise ratio (SNR) before detection, the OAM wave RCS diversity characteristics under multistatic is studied. Moreover, a pulse pair processing scheme based on linear frequency modulation (LFM) with minimum shift-keying modulation (MSK) for multistatic radar-communication integration system is proposed, and the detection cabability of multistatic system is improved. For airborne cooperation targets, the OAM wave based second surveilance radar (SSR) system is proposed to replace the traditional SSR directional beam and mechanical rotation structure by taking advantage of the OAM omnidirectional beam, so that the SSR azimuth measurement capability does not depend on mechanical rotation.Finally, the demonstration system is designed and implemented to further verify the validity and efficiency of the proposed method.