X波段宽带低差损功率均衡器的设计与实现

功率均衡器是改善微波系统幅度响应平坦度的一种有效的解决办法。文中研究了电阻加载谐振网络及其在宽带功率均衡器中的应用。利用ADS仿真软件对电阻加载宽带功率均衡器进行联合电磁仿真设计与优化,实现了X波段宽带低差损功率均衡器。均衡器在整个频带内均衡5 dB,输入输出驻波比均小于1.5∶1,最终测试结果与初始设计相吻合,满足了工程需要。结果表明,电阻加载均衡器适用于宽带功率均衡器的研制。     

线性均衡器的研制

均衡器是重要的微波器件之一,用来改善微波系统的平坦度。研究了加载电阻的微带谐振器及其在微带均衡器中的应用。先用微波仿真软件Serenade对由加载电阻的微带谐振器构成的均衡器进行优化,再利用三维场仿真软件(HFSS)对电路进行电磁仿真检验,设计并制做了2～12GHz微带线性均衡器。均衡器在整个频带内约均衡5dB,输入与输出驻波比均小于2:1,最终实验结果与设计相吻合,满足了工程的需要。结果表明,这种加载电阻的微带谐振器方式适合线性均衡器的设计和制作。     

超宽带微带幅度均衡器的设计

本设计采用微带电路实现6—18GHz吸收式微带幅度均衡器,应用于超宽带T／R组件中。利用微波仿真软件HFSS构建电路模型．进行仿真优化设计．最后设计出均衡模块。得到设计要求的均衡器。     

基于推挽式结构大功率放大器热分析

本文为了验证大功率功率放大器在强迫风冷散热方式下的散热效果，设计了一款基于推挽式结构的大功率放大器，通过理论分析计算散热方案，使用ICEPAK散热软件仿真验证理论计算结果。考虑到功放耗散功率较大，最终采用强迫风冷和热沉的散热方式对功放进行散热。本文设计基于LDMOS功率管型号为MRF13750H，仿真设计在单频点915 MHz，输入功率35dBm时，输出功率达615W，效率为74%，耗散功率约达290 W，理论计算所需风机的风量大小为2.54 m³/min。ICEPAK软件进行仿真在耗散功率在300 W时，功率管温度为71.25℃，风机工作点为3.86 m³/min,工作静压力为201 Pa。仿真验证满足设计要求。     

一种基于GaN的0.5-4GHz高效率宽带功率放大器设计

宽带大功率微波功率放大器在通信发射机的应用越来越多,具有高击穿场强和高功率密度的优点的第三代半导体GaN技术越来越适用于宽带功率放大器的应用。本文基于GaN功率管的大信号仿真模型,采用宽带匹配技术进行功率管的匹配电路设计。通过ADS软件仿真和优化,设计了一款工作在0.5-4GHz宽频带范围的功率放大器。仿真结果显示,在0.5-4GHz内,功率附加效率(Power added efficiency, PAE)超过60%,增益大于11dB,增益平坦度为±1.5dB,且端口驻波性能良好,满足了发射机系统的要求。     

S波段超宽带固态功率放大器的研制

本文结合一款新研制的S波段超宽带固态功率放大器,介绍了超宽带固态功率放大器的设计理论和方法,根据砷化镓场效应晶体管的小信号S参数和I-V曲线,用微波仿真软件对功率管的输入、输出阻抗匹配电路及其偏置电路进行优化仿真设计.通过制作并测试此放大器,验证了该设计方法的可行性.最后,给出了测试数据,它在2GHz～4GHz的频带范围内,输入功率为40mW时,输出功率大于20W,带内功率起伏小于1.5dB.     

频率合成器、功率合成器、均衡器、衰减器

0210847多注速调管放大器的自适应均衡器研制〔刊〕/成永东//强激光与粒子束.—2002,14(1).—107～110(K) 多注速调管放大器对激励功率有十分苛刻的要求。文章提出了采用可编程控制器研制自适应均衡器的方法,自适应均衡器根据速调管输出微波峰值功率大小自动控制电调衰减器,从而达到控制速调管激励     

S波段1OWLDMOS功率管匹配电路设计

RFLDMOSs}／率管具有高输出功率、高增益、高线性、良好的热稳定性等优点,广泛应用于移动通信基站、数字广播电视发射以及射频通信领域、微波雷达系统。阻抗匹配是LDMOS~率管应用电路设计的关键任务,LDMOS功率管匹配电路的主要任务是实现功率管的最大功率传输。文中选择中国电子科技集团公司第58研究所研制的S波段10wLDMOS功率管,利用微波仿真工具ADS设计外匹配电路。经过精心调试后,s波段LDMOSs}／率管输入回波损耗、增益、输出功率、效率、谐波等技术指标达到设计要求。完成匹配电路设计的S波段LDMOS功率管在3．1～3．4GHz频率范围内,输出功率大于13．8W,功率增益大于12．4dB,效率大于37．9％。     

微波功率管特征参数测试

由于大功率全固态电子设备在体积、性能和可靠性方面的优势,微波功率管将逐步取代行波管在雷达发射机中的核心地位。随着微波功率管的大量应用,正确的测试和评价功率管性能已经显得迫切。微波功率管的特性参数包括直流和射频两部分,直流参数包括:反向击穿电压、反向漏电流和直流增益;射频参数包括:输出功率、增益、顶降、集电极效率、反射系数、1 dB过激励输出功率和抗适配等。文中对微波功率管的特征参数先从理论上阐述,然后结合DC和RF测试平台详细描述了各个特征参数的测试,得出测试结果,并对测试结果进行分析。     

微波固态功率组件相位一致性分析

在微波功率管厂家给出的常规设计数据的基础上,建立了功率管匹配的电路模型;对微波功率组件的设计和调试步骤进行了合理的归纳;分析了微波功率管在共轭匹配以及失配情况下对模块相位的影响;通过双模块间功率合成的解析式分解,给出了模块自身功率调试（实现模块功率的最大化）和模块间相位调试（实现模块间的相住一致）的具体目标和方法,以实现组件工作的高可靠和合成效率的最大化。文中针对P波段固态功率组件实际的配相调试过程（由于其工作波长较长的特点,使得通过改变微带线长度实现大范围移相可能性不大,从而给模块间相位调试带来困难）,通过分析、对比,给出了解决实际问题的方法和相应的设计结果。文中的试验数据和设计思想可作为其他相关工程设计参考。     

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.