应用于超高速流场电子密度分布测量的七通道微波干涉仪测量系统  

A seven-channels microwave interferometer measurement system for measuring electron density distribution in hypervelocity transient plasma flow

作　　者：马平[1] 田径 田得阳 张宁 吴明兴 唐璞[2] Ma Ping;Tian Jing;Tian De-Yang;Zhang Ning;Wu Ming-Xing;Tang Pu(Hypervelocity Aerodynamics Institute,China Aerodynamics Reasearch and Development Center,Mianyang 651000,China;School of Electronic Science and Engineering,University of Electronic Science and Technology of China,Chengdu 611731,China;School of Aerospace Science and Technology,Xidian University,Xi’an 710126,China)

机构地区：[1]中国空气动力研究与发展中心超高速空气动力研究所,绵阳651000 [2]电子科技大学电子科学与工程学院,成都611731 [3]西安电子科技大学空间科学与技术学院,西安710126

出　　处：《物理学报》2024年第17期138-150,共13页Acta Physica Sinica

基　　金：国家重点研发计划(批准号:SQ2019YFA0405200);国家自然科学基金(批准号:12202479)资助的课题.

摘　　要：高超声速飞行器在临近空间飞行时,由于飞行器与空气剧烈的相互作用,形成包含等离子体鞘套和尾迹的等离子体流场,研究其电子密度分布特性对高超声速飞行器的目标识别、测控通信等具有重要意义.地面模拟实验测量是研究等离子体包覆高超声速飞行器电磁散射特性的有效方法之一,为满足地面模拟实验瞬态等离子体流场电子密度分布的测量需求,本文提出了一种Ka波段七通道微波干涉仪测量系统研制方案.该系统采用单发七收的方式,利用单曲面透镜将波导开口天线辐射的电磁波转化为近似平面波,将7个平行且非对称排列的开口波导作为接收通道天线,缩减了接收天线的尺寸以及天线之间的距离,提高了测量的空间分辨率.基于七通道微波干涉仪测量系统在弹道靶和激波管设备开展了动态实验,测量了超高速流场电子密度二维分布,结果表明该系统具备瞬时大动态范围信号的接收能力,幅度线性动态范围优于65 dB,相位动态范围180°,响应时间优于1μs;所测量的超高速流场等离子体电子密度二维分布,能够较好地反映弹道靶设备与激波管设备产生的瞬态等离子体细节变化,电子密度测量动态范围为(10^(10)-10^(13))cm^(-3)量级,电子密度测量误差不超过0.5个数量级,径向空间分辨率优于15 mm.When a hypersonic vehicle is flying in the near space region,the strong friction between the vehicle and the air can cause the air to ionize.As a result,the plasma sheath around the vehicle and the wake flow field behind it are formed,significantly affecting the electromagnetic(EM)scattering characteristics of the vehicle and resulting in the communication blackout.Therefore,the investigation of electron density distribution of the plasma sheath and wake flow field is of the great significance in the detection,communication,etc.of the hypersonic target.In order to meet the requirements for on-ground electron density distribution measurement of the transient plasma flow fields,the feasibility of measuring electron density profile with seven-channel microwave interferometer measurement system is demonstrated in this work.The wake plasma is modeled as a non-uniform multilayer medium,and the full-wave simulation software FEKO is used to calculate the phaseshift information of EM wave transmitting through non-uniform single-layered dielectric plate,uniform and non-uniform multi-layered dielectric plates.According to the simulation results,the dielectric constant of the substrate is retrieved and compared with the preset result.The retrieved results show that it is feasible that the dielectric constant distribution of non-uniform multi-layered dielectric plate is measured by utilizing the proposed microwave interferometer system with one transmission port and seven receptions.The amplitudephase dynamic range analysis of the proposed Ka-band microwave measurement system is also carried out.The key technologies including large instantaneous amplitude-phase dynamic range and ray tracking inversion algorithm for two-dimensional(2-D)electron density distribution are also developed.Finally,the complete scheme of Ka-band seven-channel microwave interferometer measurement system is introduced.The system includes one lens antenna to generate the required plane wave and seven open-ended waveguide receiving antennas which are asy

关 键 词：超高速流场 等离子体 微波干涉仪 电子密度 分布测量 

分 类 号：TH744.3[机械工程—光学工程]