小型圆形贴片谐振器宽带带通滤波器设计

提出了一种频率在3.1~6.5GHz范围内的新型小型宽带带通滤波器。该滤波器结合圆形贴片谐振器的多模特性,通过引入输入端和输出端之间的耦合,增加了传输零点。通过三维仿真软件Ansoft HFSS中建模并优化,实现了通带内抑制在-20dB以下,低频段在1.9GHz处产生一个传输零点,高频段在7.6GHz处产生一个传输零点,带外抑制在-20dB以下。实测滤波器的结果与仿真结果基本一致,验证了设计的有效性。     

多传输零点LTCC带通滤波器的设计与实现

提出了一种阻带具有多个传输零点的带通滤波器设计方法,基于低温共烧陶瓷(LTCC)技术实现,可满足移动通信用滤波器小型化、高性能的要求。在电路设计中,通过改进滤波器谐振器结构,分别在阻带的低端近端、高端远端引入传输零点以提高带外抑制。借助三维仿真软件,进行指标、结构的仿真优化,设计并制作了一款尺寸为6 mm×3 mm×2 mm的LTCC滤波器,其中心频率f0=2.25 GHz,0.5 dB带宽不小于100 MHz,通带内损耗不大于1.8 dB,在1.33,1.78 GHz和二次谐波处均有传输零点。实测结果表明,该滤波器在阻带低端和二次谐波处有较好的抑制,因此其在移动通信系统中会有广泛应用。     

基于SRR-DGS 新型高选择性带通滤波器的设计

通过在阶梯阻抗谐振器(Stepped Impedance Resonators, SIR)上加载开口谐振环缺陷地结构(Split- Ring Resonator Defected Ground Structure, SRR-DGS),设计了一款具有高选择性和较好带外抑制性能的带通滤波器。 测试结果表明,该滤波器的3 dB 工作频带为2. 56 ~2. 77 GHz (7. 9%),带内最大插入损耗为0. 8 dB。此外,在通带 两侧各有两个传输零点,分别位于2. 17 GHz、2. 48 GHz、2. 86 GHz 和3. 81 GHz,带外抑制均大于30 dB,表明该滤波 器具有较好的带外抑制特性。同时,仿真与测试结果吻合较好,验证了该滤波器设计方法的有效性。     

一种全容性耦合直线型介质波导滤波器的设计

文中设计了一种新型的全容性耦合直线型介质波导滤波器,由两个深的容性盲孔和一个浅的调试盲 孔组成容性耦合结构,产生弱感性耦合,使得通带高端产生传输零点,从而解决了一般直线型耦合滤波器难以实现 交叉耦合传输零点的问题,并满足了工业应用对滤波器外形“直入直出”的需求。依照仿真对滤波器进行实物加工, 测试的滤波器中心频率3. 5 GHz,当频率在3. 42 ~3. 58 GHz 时,带内插入损耗小于1 dB,回波损耗小于15 dB,在带 外频率3. 8 GHz 处产生传输零点。测试结果与仿真结果高度吻合,验证了该滤波器结构简单、易于调谐、滤波性能良 好,能够满足基站通信的应用需求。     

一种高抑制小型化带通滤波器

该文提出了一种具有3个传输零点的高带外抑制小型化带通滤波器。通过耦合控制可在梳状线滤波器响应中引入3个传输零点。通过源/负载耦合和传输线上刻蚀的马刺线可降低带外抑制,使滤波器获得更好的性能。设计并制作了一款小型化带通滤波器实物,仿真结果表明,该文设计的滤波器工作中心频率和相对带宽分别为2.12 GHz和20%,该滤波器的回波损耗优于40 dB,插入损耗小于0.2 dB,带外抑制小于40 dB。此外,该滤波器还具有结构简单紧凑、易加工等特点,实物测试结果与仿真结果基本一致。     

具有高带外抑制特性的滤波器天线集成设计

利用滤波器综合设计方法设计了一款新型的具有高带外抑制性的微带滤波器天线。滤波器天线由五个开口谐振环、平行耦合线和倒L 天线组成。设计思路是使用倒L 天线代替滤波器的最后一个谐振器,然后利用平行耦合线等效为导纳变换器将谐振器与天线进行耦合,从而设计出既有滤波性能又有辐射性能的滤波器天线。滤波器天线采用交叉耦合结构,在带外有两个传输零点,大大提高了滤波器天线的带外抑制能力。滤波器天线经过仿真和测试,结果显示其反射系数S11 <-10 dB 的相对带宽为8%(2.37 ~2.57 GHz),带内增益约1.6 dBi,传输零点在带外50 MHz 处,增益下降到-25 dBi,带外整体下降到-20 dBi 以下,带外抑制特性显著。     

基于互补螺旋谐振器的SIW带通滤波器设计

在基片集成波导(SIW)结构中加载了互补螺旋谐振器(CSR),实现了具有超宽带外抑制的带通滤波器。CSR是复合左右手结构的一种,其等效电路与互补开口谐振环(CSRR)的相似,但CSR结构更加紧凑,设计更加灵活。SIW具有与传统金属波导相似的结构特点和分析方法,但它体积更小,且更容易与其它平面电路结合。将两个CSR单元加载到SIW中,会产生一个低于SIW截止频率的通带。调整两个CSR单元的位置,会在通带的两侧分别产生一个传输零点。本文设计的带通滤波器较传统的SIW滤波器体积更小,并且具有更宽的带外抑制。根据测试结果,滤波器的中心频率为7.68GHz,3dB带宽为394 MHz,带内插损最小值为1.91dB,带外抑制在9~18GHz范围内优于30dB。     

基于T型枝节加载SIR的双频微带滤波器的设计

针对当前通信系统需要滤波器支持多频段、小型化和高性能等要求,提出了一种基于T型枝节加载SIR的频率独立可控双频微带滤波器结构。针对该谐振器,利用提出的特殊电耦合结构实现滤波器的小型化,并引入零度馈电结构构造传输零点来改善阻带抑制,最终得到覆盖WLAN 2.4 GHz和WLAN 5.2 GHz两个频段且占用尺寸仅为16.5 mm×21.7 mm的双频微带带通滤波器。由仿真结果显示,两个通带的中心频率分别为2.45 GHz和5.2 GHz,带内最小插入损耗分别为0.35 dB和0.47 dB,带内最小回波损耗分别为-44 dB和-34.8 dB,3 dB相对带宽分别为28.9%和11.3%,阻带抑制也因引入三个传输零点而大大改善。该滤波器结构整体尺寸小、插损低、频带宽且带外抑制特性好,具有一定的实际应用价值。     

基于折叠双模谐振器结构的微带带通滤波器

设计了一种采用折叠双模谐振器结构的新型双模微带带通滤波器。通过在折叠双模谐振器两侧加载交叉耦合结构,使通带两端产生一对传输零点。实验结果表明,该滤波器具有结构紧凑,体积小,损耗低,带外抑制性能好等优点,且其中心频率为3.65GHz,通带为2.5~4.8GHz,最大回波损耗优于-33.5dB,最小插入损耗为-0.18dB,实测结果和仿真结果相吻合。     

基于折叠双模谐振器结构的微带带通滤波器

设计了一种采用折叠双模谐振器结构的新型双模微带带通滤波器。通过在折叠双模谐振器两侧加载交叉耦合结构,使通带两端产生一对传输零点。实验结果表明,该滤波器具有结构紧凑,体积小,损耗低,带外抑制性能好等优点,且其中心频率为3.65 GHz,通带为2.5～4.8 GHz,最大回波损耗优于-33.5 dB,最小插入损耗为-0.18 dB,实测结果和仿真结果相吻合。     

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.