导电平面上槽与缝的散射

在雷达散射截面（ＲＣＳ）和电磁脉冲（ＥＭＰ）研究中，我们常常需要考虑目标上各个部分结合处存在的槽或缝的散射。在现代，随着ＲＣＳ减缩技术的发展，这些槽和缝对目标双站散射行为的影响已经日益突出。对此，通过等效原理导出相应问题的全波公式，研究了具有不同形状和不同材料填充的槽或缝对目标散射图形的影响。     

低RCS雷达天线技术的研究和应用

设计和使用具有低ＲＣＳ性能的雷达天线是一项涉及到多项研究领域的课题，一直为国内外所关注。随着对天线散射机理的深入分析，一些创意较新的天线ＲＣＳ减缩技术被提出，如本文介绍的以抑制天线模式项散射为主的选频副反射面和馈源滤波罩等技术，这些技术不但具有较好的低ＲＣＳ性能而且具有较好的适用性，频率选择表面（ＦＳＳ）技术已被广泛地用于卫星多频段通讯，而在低ＲＣＳ雷达天线技术方面同样也具有极其重要的应用价值，ＦＳＳ方面的研究成果有效地改善了使用ＦＳＳ的低ＲＣＳ天线的性能，而低ＲＣＳ天线技术发展的需要又反过来对ＦＳＳ提出了更高的要求，本文对国内外在ＦＳＳ研究方面的成果和发展趋势也作了分析和介绍。     

复杂目标双站图形电磁计算

应用物理光学法（ＰＯ）与等效电磁流法（ＥＣＭ）分别计算了复杂目标双站散射中面元与棱边的散射场。在ＷＩＮＤＯＷＳ ＮＴ／９８微机平台上利用软件图形标准接口Ｏｐｅｎ ＧＬ和硬件图形加速卡对目标和背景像素进行实时显示和自动消隐,通过对各像素点的散射场计算和要位综合求得总散射场,从而将ＧＲＥＣＯ扩展为双站图形电磁学。数学模型和实例说明了本方法的正确性,对＊＊战斗机双站ＲＣＳ进行计算,对将来虚拟现实系统环境     

葡萄糖氧化酶结构的表面增强拉曼光谱研究

用ＣＷ－Ｎｄ：ＹＡＧ１０６４ｎｍ激光作为激发光源获得了葡萄糖氧化酶（ＧＯ）在银胶中的高质量的近红外傅里叶变换表面增强拉曼散射谱（ＮＩＲ－ＳＥＲＳ）。与以往可见区的葡萄糖氧化酶的ＳＥＲＳ（只反映ＧＯ中自由黄素的结构）的某些峰位和强度有明显不同，获得了ＧＯ分子更丰富的结构信息。另外，银胶中用于进一步提高ＳＥＲＳ灵敏度的各类添加剂（ＨＣｌ，ＫＣｌ，ＮａＯＨ等）均不能使ＧＯ的ＳＥＲＳ进一步增强。     

多雷达联网对低散射截面积(RCS)目标检测能力研究

由于采用特别的外形设计和一定的涂复材料，使有些目标的雷达散射截面积（ＲＣＳ）很小。雷达能发现一般的目标，而很难发现低ＲＣＳ的目标，但是这些目标不是所有方向都有低ＲＣＳ特性。这就给多雷达联网提供检测这目标的可能性。本文首先是研究多站联网比单站目标检测性能改善，即检测目标距离的改善（或折合信噪比），但是这种改善是和目标的位置，运动方法和姿态有关。     

天线模式项散射分析与天线RCS减缩

天线的散射场是由结构散射场和模式散射场两项组成。理论分析和实验结果表明，后者对天线的雷达散射截面（ＲＣＳ）的贡献比前者要大得多，有效地克服模式散射场将会明显地降低天线的ＲＣＳ。本文提出了一种以克服面天线模式用射场达到降低天线雷达截面的模式项消去法减缩天线ＲＣＳ技术，并在几种天线模型上进行了实验。实验结果证明，这种技术减缩天线ＲＣＳ的效果，不管在天线工作频带内还是频带外均可达到１０￣１５ｄＢ。模式项     

相干反斯托克斯喇曼散射光谱在推进剂火焰温度和浓度测量中的应用

本文介绍了相干反斯托克斯喇曼散射（ＣＡＳＲＳ）光谱测量推进剂火焰温度和浓度的原理，给出了实验原理图，表明了ＣＡＳＲＳ技术在推进剂火焰温度和浓度测量中具有明显的优越性和实际意义。     

CS_2的瑞利增强四波混频研究

ＣＳ＿２的瑞利增强四波混频研究姜谦，俞祖和，米辛，李晓峰，傅盘铭（中国科学院物理研究所北京１０００８０）相干拉曼光谱是研究分子振动和转动模的强力工具。除了常用的相干反斯托克斯拉曼散射（ＣＡＲＳ）和拉曼感生克尔效应（ＲＩＫＥＳ）外，拉曼增强非简并四波混...     

雷达图象数据的规格化及解释

校准后的雷达图象通常量化为雷达截面积（ＲＣＳ）。从严格意义上说，这一解释并不正确，会使人对测试目标的散射特性产生误解。为了避免不必要的混淆，建议采用“散射亮度”（其定义见下文）这一术语作为图象域数据的标准标记。     

IPO-MoM混合法分析开槽电大目标的电磁散射

本文利用迭代物理光学法（ＩＰＯ）与数值方法相结合的混合方法计算二维开槽民大目标的电磁散射,首先根据等效原理将散射场进行分解,分别采用ＩＰＯ法和矩量法（ＭｏＭ）计算槽缝填充的电大目标和槽缝的散射,并在口径处应用广义网络原理处理耦合问题,数据结果表明本文方法是准确和高效的。     

飞机舵面缝隙缺陷建模及电磁散射特性分析

为了研究飞机舵面缝隙在飞机头向威胁角域的散射特性,提取舵面前端缝隙设计了雷达散射截面(Radar Cross Section,RCS)数值仿真分析模型.采用混合场积分方程和多层快速多极子算法进行了RCS仿真计算,并以RCS峰值、波峰宽度、均值增量三个评价指标分析散射特点.舵面前端缝隙的垂直极化散射明显(不同频率下的均值...     

Radio-frequency leakage into missiles

Missile functions are often initiated by the detonation, upon command, from either a wire or radio circuit, of sensitive electroexplosive devices. The possibility exists of inadvertent detonation of these devices caused by the leakage of radio-frequency energy into the missile from high-power radar or communications facilities. This paper treats the idealized problem of RF energy leakage through a slot in an infinite cylinder as a perturbation on the scattering problem for the same object with no slot. It is shown that interior response depends on three factors: the exterior skin current density from the scattering problem, the transmitting admittance of the slot, and an eigenfunction expansion of the interior field when unit voltage is impressed across the slot. It is then proposed that the form of this solution may be applicable and conceptually useful in treating other problems either theoretically or experimentally.     

Using electromagnetic scattering to estimate the depth of a rectangular slot

A theory for predicting the electromagnetic scattering from a rectangular slot is developed and is used to evaluate the possibility of determining the slot depth from scattering measurements. Experimental results obtained at 100 GHz are presented and compared with theory. Practical limitations of the technique are discussed.     

Dielectric image line groove antennas for millimeter waves, Part I: Theoretical background

Dielectric image line groove antennas are very useful for the application in the millimeter-wave region. In this first part of a two-part paper, three different types of groove discontinuities under a dielectric image line for application in millimeterwave antennas are investigated: the equivalent circuits of 1) a slot discontinuity in a metallic ground plane and 2) a slot discontinuity in the metallization of a substrate material under a dielectric image line are derived theoretically using an approximation for the electromagnetic fields of the slots. 3)The equivalent circuit of cylindrical holes in a metallic ground plane under a dielectric image line is derived from measurements. The results are used to synthesize millimeterwave dielectric image line antenna arrays as described in part II of the paper.     

Full-wave analysis of broad wall slot's Characteristics in rectangular waveguides

A rigorous analysis of the resonant characteristics for a broad wall waveguide slot by using the finite-difference time-domain method is presented. Four types of slots including a radiating longitudinal shunt slot, a longitudinal/transverse coupling slot, a centered-inclined coupling slot and a compound coupling slot are analyzed. Lots of slot characteristics such as the resonant length, scattering parameters and normalized admittance in different offsets, tilt angles or slot sizes are obtained. Because the shape of slots is a rectangle with rounded ends in practical fabrication, an accurate modeling and computation for the slots with rounded ends is implemented, and the resonant lengths calculated coincide well with the Stegen's measured data and method of moments results. From these computed results, it is found that all the resonant characteristics of the slots with rounded ends are significantly different from those with normal rectangular ends.     

圆形槽波导-波纹圆形槽波导模式变换器的仿真设计

应用基于有限元方法的仿真软件HFSS,分析和设计了圆形槽波导-波纹圆形槽波导模式变换器。变换器由具有渐变波纹深度的波纹圆形槽波导构成,可实现TE11到HE11的模式转换。分析表明,变换器的长度和第一个波纹的深度是影响其性能的主要因数。在保持变换器优化长度不变的条件下,调整波纹周期、增加波纹数目和波纹宽度对改善变换器的性能效果不明显。所设计的具有5个渐变深度波纹的模式变换器,在中心频率36GHz上回损可达30dB。变换器实测的结果与仿真分析之结论吻合较好。     

一种基于PBG结构的多频微带天线的分析与设计

在C型缝隙微带天线介质基板内引入光子晶体结构,设计了一种基于PBG结构的多频微带天线,此天线采用在C型缝隙天线贴片下方挖出凹槽,将辐射板放入凹槽中,并在微带天线的介质基板中引入高度不同的周期性三角柱空气隙PBG结构的设计方案.采用基于有限元方法的电磁仿真软件Ansoft HFSS10.0对所设计的天线进行了仿真.与普通...     

Characteristics of a longitudinal/transverse coupling slot incrossed rectangular waveguides

A rigorous analysis of a broad-wall slot coupler between two crossed rectangular waveguides is presented. The slot is longitudinal and offset from the center line in the main guide and is centered transverse in the branch guide. Integral equations are developed, taking into account finite wall thickness. The integral equations are then solved for the aperture electric field. Coupling slot characteristics are obtained, including the resonant length and dominant mode scattering. Numerical results for resonant length and scattering parameters are presented over a range of offsets, waveguide dimensions, and frequencies     

Compound radiating slots in a broad wall of a rectangular waveguide

An analysis is presented of the characteristics of a broad wall radiating slot, offset from the center line and tilted with respect to the longitudinal axis of a rectangular waveguide. Pertinent integral equations are developed, taking into account finite wall thickness, and are solved for the slot aperture E-field using the method of moments. Compound slot characteristics are then deduced, including resonant length and dominant mode scattering. Numerical results for the scattering from resonant slots are presented over a range of offsets, tilt angles, frequencies and waveguide dimensions. For resonant compound slots, offset and tilt are shown to control the aperture electric-field amplitude with a phase variability of 360°. The results have significant applications in the design of compound slot arrays     

缝隙天线阵双站电磁散射的混合法

利用矩量法（ＭＯＭ）和等效边缘电磁流方法（ＥＥＣｓ）研究波导馈电的缝隙天线阵的双站散射问题。从理论和计算上分析,等效边缘电磁流方法可以计算有限尺寸的导体平板沿任意方向上的双站散射（包括边缘绕射场）,而矩量法可以考虑波导缝隙天线阵的散射与耦合问题,使它们混合便可以解决有限尺寸缝隙在线阵的散射问题。实际计算表明,方法是切实可行的。