基于氮化铝技术的X波段瓦片式T/R组件的研制

有源相控雷达阵的发展对关键部件T/R组件的体积和重量提供了更高的要求。为满足这一要求,设计了一种基于氮化铝(Al N)技术的X波段瓦片式T/R组件,该组件突破传统的瓦片式T/R组件设计理念和实现方式,封装形式为表贴型,仅由一块基板组成,且功能齐全。组件重量为6 g,很好地满足了有源相控雷达阵对T/R组件小型化、轻量化的要求。     

一种调频连续波阵列雷达的软件校准方法

提出了一种应用于调频连续波阵列雷达的软件校准方法,首先建立了非线性VCO特性和空间误差的雷达模型,通过时间域对发射机VCO的非线性进行快速补偿校准以及空间域对天线线阵间通道相位、幅度和时延的校准,最终使得雷达线性调频信号和阵面方向图满足设计要求.通过基于宽带X波段调频连续波雷达的仿真与实验分析,表明通过该软件校准方法可...     

基于模拟退火的雷达-通信共享孔径研究

针对机动作战平台天线共享需求,提出了一种面向雷达通信一体化的线阵共享孔径分配方法.首先,建立了共享孔径的模型,根据雷达和通信工作频率差异设计了非均匀线型共享阵列;其次,将阵元位置的分配转化为多目标优化问题,选择雷达阵列方向图的最高旁瓣电平和通信阵元的信道容量作为优化目标;最后,用改进的模拟退火算法进行优化计算,并完成了相关的仿真实验,结果证明,雷达最高峰值旁瓣电平和通信信道容量能同时达到工作要求,实现了天线孔径的共享.     

基于L形嵌套的混合MIMO相控阵雷达阵列设计

混合MIMO相控阵雷达发射端的子阵分割会导致自由度损失,为了解决这一问题,提出了一种基于嵌套阵结构的L形收发阵列设计方法。首先将发射端的混合MIMO相控阵雷达线阵纵向放置,然后接收阵列设计为横向布置的嵌套阵结构,最后通过在虚拟阵列中构造差异阵列,以L形的线阵结构实现了二维混合MIMO相控阵雷达的功能。通过形成虚拟阵元数目扩展,在保留混合MIMO相控阵雷达优势的同时增大了阵列自由度。且本文给出了这种结构下阵列流形的闭合表达式。仿真结果表明,与传统的混合MIMO相控阵雷达相比,这种方法能够提高自由度和波达方向估计精度。      

光纤传输在数字阵雷达中的应用

分析了数字阵雷达的信号特点和传输要求,采用光纤传输技术设计了阵面上下之间的信号传输链路.设计运用数字复接和光波分复用的方法大幅度提高了单纤信道的传输容量,有效解决了数字阵雷达阵面大赶L/Q数据的回传问题;运用电中继与光功率分配相结合的方法实现了上行光信号的传输和广播式发送.设计综合分析了信道数量、带宽、传输距离、延时、抖动等因素对系统性能和扩展的影响.工程实践表明,光传输系统能够有效解决数字阵雷达的信号传输要求.     

机动型雷达平面阵列天线的结构设计

天线作为辐射和接收雷达电磁波的主体,要求有相当高的阵面精度、刚度和强度。本文分析了机动型雷达平面阵列天线结构设计的特点,结合某机动雷达天线系统的设计,着重介绍了在该类天线设计中如何解决机动性与有限空间尺寸,空间与刚度,刚度与重量,高精度与可分解性等诸多矛盾,指出恰当处理这些问题是该类天线设计成功的关键所在。     

雷达阵面系统小型化研究

雷达阵面系统的小型化研究在机载、弹载、星载等雷达领域有重要应用价值.文中从三方面提出了小型化设计思路:1)多功能线阵设计.从系统的角度优化天馈线形式,通过一种新型耦合器的设计,将天线与馈线多功能、一体化设计,使辐射线阵不仅具备监测功能,同时结构比常规线阵缩小25％;2)三维微波-数字混合电路设计,通过对三维垂直互联机构的建模分析,提高三维微波电路设计的准确性,同时从电路布局、屏蔽、端接匹配电路等方面提出了三维微波-数字混合电路设计规则;3)微波-数字协同仿真.通过三维微波-数字电路的仿真,解决了Ku波段三维微波电路易谐振,性能不佳的问题和复杂信号传输易串扰、数字信号传输信号完整特性欠佳的问题.实验验证了上述措施的有效性,一定程度上实现了阵面电讯、结构等系统整体资源的优化配置,使雷达阵面系统实现高集成、小型化设计.     

天线线阵自动测试系统工程设计

相控阵天线的蓬勃发展,对天线线阵测试效率提出了迫切需求。文中提出了一种相控阵天线线阵自动测试系统的工程设计方法,该方法通过增加对天线线阵、微波矩阵开关以及测试仪表的控制,实现传统天线线阵手动测试系统的升级,使其具备对相控阵雷达天线线阵自动测试和故障隔离的功能。该测试系统用于多型线阵的测试,大幅提高了测试的效率,完善了雷达线阵的测试技术。     

机动型雷达平面阵列天线的结构设计

天线作为辐射和接收雷达电磁波的主体,要求有相当高的阵面精度、刚度和强度。本文分析了机动型雷达平面阵列天线结构设计的特点,结合某机动雷达天线系统的设计,着重介绍了在该类天线设计中如何解决机动性与有限空间尺寸,空间与刚度,刚度与重量,高精度与可分解性等诸多矛盾,指出恰当处理这些问题是该类天线设计成功的关键所在。     

考虑互耦的切比雪夫线阵天线波束形成

低副瓣是当今电子对抗时代中对雷达天线的必然要求,但由于阵列天线单元间有互耦的影响,实际的天线单元电流分布往往达不到我们设计的要求。本文在介绍切比雪夫线阵的设计公式和互耦的矩量法分析方法的基础上,首先用矩量法精确分析了考虑互耦影响时切比雪夫线阵天线阵元的电流分布,仿真实现了阵元互耦对切比雪夫线阵各阵元电流幅度及相位的影响效果以及互耦对切比雪夫线阵天线波束形成的影响效果,接下来用软件的方式补偿互耦所造成的影响,从而完成了切比雪夫线阵天线波束形成的综合。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.