用于回旋速调管的新型开放式球形谐振腔

作为毫米波、亚毫米波源的回旋速调管工作于W波段及以上波段时,如何提高输出功率和工作效率是回旋管研究的重点.对开放式球形腔TE谐振模式的特点进行了理论分析,并与圆柱谐振腔TE模式进行了比较,通过计算模拟对比了二者谐振腔的电场能量分布特点.与圆柱谐振腔TE021模式相比,在电子通过区域,开放式球形腔内TE102谐振模的高频...     

94 GHz TE_（02）-TE_（11）模式变换链的设计与模拟

本文在电磁场耦合模理论的基础上利用MATLAB优化工具对W波段回旋管用TE02-TE01-TE11模式变换链进行了详细研究与分析。应用编制的仿真程序对W波段TE02-TE01-TE11模式变换链进行了设计和数值模拟,通过结构参数优化,获得了性能良好的模式变换链。TE02-TE01和TE01-TE11模式变换器在中心频率94 GHz处的转换效率分别为96.3%和94.1%,对应带宽分别为4 GHz（转换率95%以上）和2 GHz（转换率90%以上）。为了进一步验证设计的模式变换链的性能,利用高频模拟仿真软件HFSS对优化的模式变换链进行了模拟仿真,模拟结果与利用计算程序得到的结果基本吻合。     

模式抑制器在Ku波段在线测量系统中的应用

在Ku波段低磁场相对论返波管中,由于阴极发射的角向不均匀性,产生的微波除了TM01模,还有主模TE11等其他微波模式。由于目前设计的圆波导耦合器只能测量TM01模式功率,其他微波模式存在会导致在线微波波形异常,给在线测量带来困难。本文设计了一种模式抑制器,其结构由5个腔组成。通过数值模拟和实测结果得出：TM01模在频率14.8~15 GHz衰减小于0.1 dB,而对其他模式,如主模TE11模式微波能够全反射。模式抑制器置于相对论返波振荡器(RBWO)与圆波导耦合器之间,实验观察在线输出微波与辐射场波形一致,微波功率符合较好。     

Ka波段TE_（01）模回旋速调管带新型渐变段输出腔设计

利用正余弦拟合的方法和半径渐变波导的耦合波理论,设计出一种Ka波段TE01模回旋速调管带该新型渐变段输出腔。通过Matlab数值计算和HFSS仿真优化,研究了该新型渐变段的传输参数、反射参数、对杂模的抑制等性能指标。仿真结果表明：在渐变段长度为80mm、口径由14mm变化到32mm的情况下,在33～35GHz的范围内该新型渐变的传输参数大于-0.016dB,反射参数小于-55dB,对TE02模的耦合为-25dB和对TE03模抑制在-55dB以下;而该输出腔的中心频率为34.075GHz,Q值为109.6,工作模式TE01模式的模式纯度大于0.94。     

一种X波段GW级TE21模耦合器的设计

针对目前高功率微波(HPM)传输与发射系统无法实现自跟踪的问题,引入TE21模耦合器,使HPM系统具备自跟踪能力。由于现有的TE21模耦合器应用到HPM中会面临功率容量的问题,为此设计一种X波段GW级TE21模耦合器,以探索其在HPM系统中的应用。仿真结果表明：设计的TE21模耦合器在9.0~10.0 GHz频率范围内,对TE21模的耦合度大于-0.5 dB,对TE11模的耦合度小于-40 dB,功率容量可达到GW量级。     

Ka波段高功率基波回旋速调管高频系统研究

对Ka波段、工作模式为TE021,模的基波高功率回旋速调管的高频结构进行了研究.讨论了群聚腔两端突变对TE02模反射相位和幅值,以及绕射产生的TE01模的相位和幅值的影响;TE01模相干迭加效应和对TE02模场分布形式的影响,通过粒子模拟计算研究了最具破坏性的杂模.优化设计了腔体的尺寸,使得既降低了TE01模对工作模TE02模的影响又有效抑制了最具破坏性的杂模,并得到了34GHz的TE021模四腔回旋速调管放大器设计方案.PIC计算表明:在工作电压70kV,注电流20A,电子横纵向速度比为1.5时,中心频率33.97GHz,输出功率720kW,相对带宽1.5%,电子效率51.4%,饱和增益大干49.7dB.     

W波段低损耗径向功率合成器设计

介绍了一种采用圆波导TE01模式转换实现的W波段低损耗径向功率合成器。设计出了16路圆波导TE01模径向合成器和圆波导TE01模转换器,整体结构简洁紧凑,利于加工制造。对合成器在85～105 GHz的频带内进行了背靠背测试,驻波低于1.35。扣除模式转换器的损耗,单个径向合成器损耗小于0.35 dB,合成效率大于92%。     

W 波段全带宽TE10-TE20模式转换器的研制

新一代W波段慢波结构行波管对波导TE10-TEn0 模式转换器的低损耗、宽带、转换效率等高性能方面提出了要求。 文中重点研究一款全W波段波导模式转换器的设计,实现E 面TE10 输入到H 面TE20 输出的模式转换,并结合高效率转换 结构,给出实际性能验证。首先,分析了波导TEn0 模分布特点,提出E 面功分结构、集成扭波导结构及H 面反相合成等单元 结构;其次,给出TE10-TE20 模式转换整体方案设计与电路优化;最后,结合H 面异相功分结构集成,基于计算机数控技术,实 现该W波段模式转换模块的制备,并完成三端口性能测试。实测结果表明,W 波段全带宽内(75 GHz~110 GHz),该TE10-TE20 模式转换模块输出端口功率分配比为-3.2 dB±0.2 dB,相位差为180°±2°,输入端口回波损耗优于-20 dB,且实测性能 均与仿真结果高度一致,验证了W波段宽带TE10-TE20模式转换器的高效率、低损耗、可行性及鲁棒性。     

一种同轴波导TE01模到圆波导TE02模变换器的数值模拟

该文对一种同轴波导TE01(°)模到圆波导TE02(°)模变换器进行数值模拟研究.通过分析同轴波导与圆波导对接产生的模式转换效果,探讨尖劈模式变换段改善工作模式转换系数和工作频带以及抑制寄生模式的作用.利用Ansoft HFSS对模型进行的数值模拟计算结果表明,这种结构能够实现最大将89.3%输入信号能量转换到TE02(°)模,-3dB带宽约820MHz,带内对主要干扰模式TE01(°)的抑制在10dB以上.     

采用矩形到同轴扇形渐变TE□10→TE☉01模式变换器带宽特性的研究

该文对一种矩形到同轴扇形渐变TE□10→TE☉01模式变换器的带宽特性进行了研究.分析了工作频带内竞争模式对工作模式的影响,探讨了滤模加载对改善模式转换性能的作用.模拟结果表明,滤模加载可以削弱竞争模式对工作模式的影响.加滤模结构后,模式变换器工作在Ku波段时,在模式转换效率大于70%的情况下,带宽可以大于700MHz.     

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.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

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.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

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.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

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.     

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.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.