采用倒相换能器结构的宽带SAW延迟线

报道了两种采用倒相换能器（ＰＲＴ）结构设计的声表面波宽带延迟线，一种制作于石英材料之上，另一种制作于ＬｉＴａＯ＿３基片之上，其相对带宽均大于２２％。     

声表面波延迟线

声表面波延迟线是在雷达和通信系统中应用非常广泛的器件.文中结合实用声表面波延迟线器件的设计实例,介绍了折叠式固定延迟线结构原理和设计计算,克服了传统延迟线受基片材料长度和器件尺寸的限制,满足了雷达、通信等电子设备中对电信号的长延迟需求;同时还讨论了为满足超高频的应用需求和增加相对带宽,所采用的谐波和倒相换能器的设计方法.     

大功率反射式体声波微波延迟线

本报告介绍了采用Au/Cr/ZnO/Au/Cr/Z-Al_2O_q一维纵向薄膜换能器结构,研制成大功率反射式体声波单端口网络的微波延迟线.在中心频率f_0=2780MHz,带宽△f=200MHz,延时t_1≥8μs,t_2≥16μs,电压驻渡比VSWR≤2.0,匹配状态下承受脉冲功率20W.     

西安电子工程研究所微电子中心

声表面波部 从事声表面波技术的研究工作已有四十多年，开发了几百个品种的声表面波滤波器，脉冲压缩延迟线等。主要产品有CCTV的频道滤波器，中频滤波器，传感器用延迟线，谐振器，相位编码匹配滤波器，抽头延迟线，GSM、CDMA基站中频滤波器，通讯用70MHz、140MHz滤波器等，可供用户随意选用。     

高可靠性声体波微波延迟线研究

通过优化换能器设计和采用双面光刻、超声键合和密封封装等技术,研制出中心频率f0=4 300 MHz,-3 dB带宽Δf-3 dB≥200 MHz,延迟时间Δt=0.358μs的声体微波延迟线。通过试验验证,该产品具有高可靠性和良好的环境适应性,取得了满意的实用效果。     

40微秒声表面波色散延迟线

声表面波色散延迟线可用于脉冲压缩雷达,解决雷达作用距离和距离分辨力之间的矛盾,还可用于脉冲多卜勒雷达,测量多卜勒频移,因此,在雷达信号处理中受到重视.声表面波色散延迟线充分体现了声表面波器件设计灵活的优越性,因此都乐于研制.声表面波色散延迟线的性能主要由叉指换能器决定.分析叉指换能器的方法通常有δ模型、等效电路模型和连续集模型,其中连续集模型简单易行.有人运用连续集模型,提出了用声脉冲与叉指换能器相互作用的     

声表面波短延迟线中的直通信号抑制问题

延迟线是基本的声表面波器件之一,在雷达、通讯、电子对抗、声纳和电视等方面有很广泛的应用.在声表面波延迟线中,一般把延迟时间在1微秒以内的延迟线称为短延迟线.有的延迟时间甚至低至0.1微秒.延迟时间愈短,必然是输入叉指换能器和输出叉指换能器靠得愈近.我们以中心频率20的赫延时0.488微秒的延迟线来说明.假定输入和输出换能器都是4对指的话,那么换能器的空间周期λ与两换能器的内边缘距1′之比约是1/5.5.可见两个换能器是靠得近的(图1).这就是短延迟线结构上的特点.     

一种新型大带宽高通带平坦度延迟线的设计技术

采用倾斜换能器结构,通过优化设计,研制出中心频率800MHz,带宽200MHz,延迟时间为100ns～3μs且精确可控的声表面波延迟线。该系列产品的插入损耗约为-25dB,直通抑制大于35dB,三次渡越抑制大于50dB,200MHz通带内波纹小于1dB,产品综合性能指标优异。     

表面波抽头延迟线非相干扩频调制解调器

表面波抽头延迟线非相干扩频调制解调器使用m序列相位编码表面波抽头延迟线作为相位编码波形发生器和匹配滤波器。它具有4MHz带宽和32kbit/s的数据率。表面波抽头延迟线中心频率为32MHz。在解调器中,匹配滤波器的输出经包铬检波和幅度判别,以实现对扩频信号的非相干解调。该系统具有简单和快速同步的特点。     

基片开槽抑制SAW滤波器体声波的工艺研究

当叉指换能器在基片上激励声表面波模式时，同时伴随着体声波的激励。文章根据叉指换能器的激励原理，采取对压电基片背面开槽抑制叉指换能器体声波进行了实验研究。分别在ST、LT、LN压电基片上背面开槽并制作了中心频率为28MHz、70MHz、71MHz、120MHz声表面波滤波器。实验观察了体声波的抑制情况，并得出了具体实验数据。     

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.     

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.     

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.     

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.     

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.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.