小型化UHF弯折偶极子抗金属RFID标签天线的设计

设计了一款可用于金属物体的超高频(UHF)射频识别(RFID)标签天线,该天线采用弯折偶极子的形式,辐射单元位于厚度仅0.508mm的Rogers 5880基片上,并且在馈电点两边使用两个对称的短路探针来达到小型化的目的。通过调整短路探针的位置和半径可以获得不同的频率响应。通过加工测试获得的该天线的数据与设计仿真结果比较符合,并且对该天线的用于非金属物体和金属物体时的阅读距离等参数作了实际测试。     

超低功耗RFID标签基带处理器

针对集成片上天线(OCA)的超高频射频识别(RFID)标签设计了一款RFID专用协议的基带处理器,以满足RFID标签嵌入纸张及微小物体的防伪功能.由于OCA与读写器天线近场耦合获取能量有限,集成OCA的无源标签对功耗要求更加苛刻.针对微小OCA标签的应用需求,采用异步电路、门控时钟、低压库、多时钟域等低功耗设计方法,设计了专用协议标签基带处理器,其CMOS低压库的设计可以使基带处理器在0.5V的电源电压下工作,综合布局布线后,其电路仿真结果表明,峰值功耗仅为0.32 μW.标签芯片在UMC 0.18 μm标准工艺下流片,测试结果显示,在读写器输出20 dBm能量的情况下,带OCA标签的读距离可达2 mm.     

用于手术剪的超高频无源小型化RFID标签天线设计

为了加强对医疗器械的跟踪管理,尤其是对手术前后手术剪数量的有效监测,设计了一款可应用于手术剪的超高频(UHF)无源小型化射频识别(RFID)标签天线。该标签天线采用集总元件加载技术以及短路技术方法实现了天线的小型化设计。通过对电容容值以及天线结构尺寸的调整,可实现对标签天线谐振频率以及标签天线特性阻抗的调节。标签天线结构参数经仿真优化,最终设计尺寸为6 mm×3 mm×1 mm。标签嵌入手术剪中的最大读取距离为1.2 m。根据仿真结果对天线加工并对实物进行测试,测试结果与仿真结果吻合较好。     

应用于RFID 的小型化双频微带天线的设计与分析

提出了一种适用于射频识别手持读写器的双频单层微带天线新颖设计,适用于超高频频段(920～925MHz)和ISM频段(2.4 ～2.5GHz)的射频识别系统.切四角和中心方形结合缝隙结构,实现了天线的小型化设计,满足了天线设计要求,选用廉价FR4板材尺寸为75mm×75mm×3mm.给出了天线设计思路,并利用电磁仿真软件分析了天线性能,仿真与测试结果吻合良好.天线测试结果表明:在917.1 ～936.5MHz频带范围内回波损耗小于15dB,在2.43～2.47GHz频段内小于-15dB;在UHF频段与ISM频段内,读写器天线的最大增益为0.02dBi和1.66dBi,所以本天线能满足我国射频识别读写器的应用要求,具有良好的应用前景.     

一种新型圆极化UHF通用型RFID读写器天线

面向超高频(UHF)通用型射频识别(RFID)读写器天线的应用需求,设计了一款完全覆盖全球UHF(840-960MHz)频段的RFID圆极化读写器天线。天线采用平面缝隙贴片结构,以共面波导(CPW)馈电方式实现宽频带圆极化特性。测试结果表明,天线的阻抗带宽为735-1014MHz(S11<-10dB),相对带宽31.9%,并且在840-960MHz频段内S11<-20dB,3dB轴比带宽为838-1134MHz,相对带宽30.0%,工作频带内有大于3.5dBi的平坦增益。仿真结果与测试结果基本吻合,天线结构精简,易于加工,满足全球UHF RFID读写器天线的应用需求。     

低压低功耗无源UHF RFID标签芯片模拟前端电路的设计

本文从设计符合EPCTM C1G2协议的超高频无源射频识别标签芯片的角度出发,对RFID标签芯片模拟前端电路进行设计.通过对各个关键电路的功耗与电源进行优化,实现了一个符合协议要求的低电压、低功耗的超高频无源RFID标签芯片的模拟前端.该UHF RFID标签模拟前端设计采用SMIC 0.18 μm EEPROM CMOS工艺库.仿真结果表明,标签芯片模拟前端的整体功耗控制在2.5 μW以下,工作电源可低至1 V,更好地满足了超高频无源射频识别标签芯片应用需求.     

小型化低剖面UHF RFID抗金属标签天线设计

针对超高频抗金属射频识别(RFID)标签的小型化和低剖面需求,提出了一种可用于金属表面的超高频RFID标签天线,其尺寸为50 mm×20 mm×0.9 mm。该设计采用CST MWS软件进行建模仿真,分析了嵌入式馈电结构尺寸变化和矩形开槽尺寸变化对标签天线输入阻抗的影响,并调整相应参数以达到标签天线输入阻抗与芯片阻抗的共轭匹配。实测结果表明,标签天线输入阻抗与芯片阻抗匹配良好,在910 MHz处有最大实测阅读距离为4.3 m,且具有小尺寸和低剖面,可应用于物流、医疗、零售等多种领域的金属场景。     

电容耦合馈电方式的宽带抗金属标签天线设计

本研究提出一种新型的超高频抗金属无线射频识别技术(Radio Frequency Identification,RFID)标签天线,该天线集成在厚度仅为0.8mm的介质板上,通过电容耦合馈电技术扩展带宽,将贴片弯曲成4个半波长的辐射单元,使得所有辐射单元的表面电流同相,由此可以增强天线增益并提高天线读取距离。最后利用HFSS软件对天线进行仿真分析,天线的回波损耗(小于-10dB)能够覆盖902~928MHz的北美超高频射频识别系统。     

用于UHF频段的RFID波束扫描阵列天线设计

为了扩大射频识别系统阅读范围和提高识别效率,设计了一款应用于多标签高效读取的射频识别( RFID)波束扫描阵列天线。采用空气层结构设计出增益值为6 dBi的圆极化天线阵元并组成2×2平面天线阵,使用开关线型移相器与威尔金森(Wilkinson)功分器设计出天线馈电网络,并使用现场可编程门阵列(FPGA)模块控制阵元间相位变化,实现波束30°偏转。整体模型尺寸为350.0 mm×350.0 mm×5.7 mm,分别使用微波暗室、射频网络分析仪以及连接RFID阅读器测试,表明天线实现了4个方向波束偏转以及识别多个标签。     

一种全球通用的小型超高频标签天线设计

为解决小型超高频电子标签的全球通用性问题,基于耦合开口谐振环对提出了一种用于超高频射频识别的新型小标签天线。经优化设计后的标签天线在电压驻波比(VSWR)<1.22时的工作频带范围可以达到790～960MHz,覆盖了全球所有超高频射频识别工作频段。采用该天线和商业标签芯片实际制作了超高频射频识别标签。通过射频识别阅读器实测表明:所设计标签天线和设计结果一致,具有较好的工作性能,能够适用于多种工作环境。该标签天线具有体积小、结构简单、易于实现和成本低等优点。     

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.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Technology innovation and process integrations for sub-100nm gate patterning

This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration.     

White organic light-emitting devices based on fac tris（2- phenylpyridine） iridium sensitized 5,6,11,12-tetraphenylnap -hthacene

We have fabricated the white organic light-emitting devices （WOLEDs） based on 4,4＇ -bis（2,2 -diphenyl vinyl）-1,1＇ - biphenyl （DPVBi） and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene （rubrene）. The device structure is ITO/2T-NATA （20 nm）/NPBX （20 nm）/CBP： x%Ir（ppy）3：0.5% rubrene （8 nm）/NPBX （5 nm）/DPVBi （30 nm）/Alq（30 nm）/LiF（0.5 nm）/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris （2-phenylpyridine） iridium [Ir（ppy）3], acts as a yellow light-emitting layer, and N,N＇ -bis- （1-naphthyl）- N,N＇ -diphenyl -1, 1＇ -biphenyl-4,4＇ -diamine （NPBX） acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir （PPY）3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.     

Complete approach to automatic identification and subpixel center location for ellipse feature

To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction.     

小角度扩展相关性近似算法分析

本论文提出一种在多天线MIMO信道相关性建模中小角度扩展近似理论算法,并应用于分析MIMO系统性能。分析中分别对三种不同角能量分布情况下的空间相关性研发快速近似计算法,并同时提出双模(Bi-Modal)角能量分布情况下的近似运算。通过分析这些新方法的近似效率,可以得到计算简单、复杂度低、而且符合实际的MIMO相关信道矩阵,对系统级的快速高效计算法的研究和系统级的评估以及误差分析具有重要的意义。     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.