一种新型双频宽负载整流电路

提出一种新型双频宽负载整流电路,它能有效回收环境中的微波电磁能量。该整流电路主要由阻抗压缩匹配网络、肖特基二极管和低通滤波器构成。其中,阻抗压缩匹配网络由一个L型阻抗调节器和一个Π型阻抗匹配器组成,该网络能够在200~4000Ω的负载区间内减小输入阻抗的变化范围,从而提高整流电路的匹配性能。ADS 2017软件仿真结果显示,该整流电路在0.8 GHz和2.4 GHz的RF-DC转换效率最高,分别能达到81.2%和77.8%,转换效率大于50%的输入功率范围在两个频点处分别为17.8 dBm和14.2 dBm,且都可在宽负载(200~4000Ω)范围内实现较高的转换效率,实测结果与仿真结果基本吻合,进一步验证了本文设计的可行性。该整流电路具有结构简单、双频、宽负载、宽输入功率等特性,对物联网、无线传感器网络和射频标签等领域的无线能量传输有一定的实用价值。     

一种基于平衡微带耦合器的宽功率整流电路

在无线功率传输系统中,接收天线整流电路的传输效率受输入功率、频率及负载变化的影响,为此设计了一种带有平衡微带耦合器的整流电路。仿真结果表明,当输入功率在8~15 dBm范围内时,该电路转换效率超过70%,最高效率为80%;转换效率在频率为2.25~2.61 GHz范围内超过70%;在负载为150~1 600 Ω范围内超过60%。与普通整流电路相比,本文提出的整流电路能够在更宽的输入功率、频带及负载范围实现高效率传输。     

基于GaAs晶体管2.45 GHz大功率微波整流电路

针对基于 GaAs晶体管的大功率微波整流电路,设计了一种应用于大功率微波无线输能系统的整流电路。该大功率微波整流电路基于微带结构,工作频率为2.45 GHz,具有质量轻,整流输出功率大的特点。在不同微波输入功率和负载下进行测量,发现当输入微波功率为30 dBm,负载为38Ω时,整流电路获得了测量过程中最大整流效率的41%;当输入微波功率为34 dBm,负载为23Ω时整流电路得到测量过程中获得的最高直流功率输出28.7 dBm。通过完善和改进电路,可以进一步提高整流的效率,并应用于高功质比的微波整流天线。     

一种紧凑型宽带高效微波整流电路

运用终端短路微带线实现无输入低通滤波器的微波整流电路。该结构串联于整流二极管与地之间,抵消了整流二极管在基频时的容性阻抗,并抑制了谐波电流,因此该整流电路移除了输入低通滤波器和匹配电路,结构和尺寸更加紧凑。理论分析和实验测试表明,本设计在较大输入功率、频率范围内实现了高效整流。实验结果表明,在输入功率12~24 dBm和频率1.48~ 2.02 GHz范围内,整流效率超过70%。当输入功率为21.8 dBm,频率为1.8 GHz时,最高整流效率为83.3%。电路尺寸优于15 mm×20 mm。     

基于ADS 获取肖特基二极管阻抗的迭代方法

在基于电磁辐射的无线能量传输与获取技术中,如何准确获取肖特基二极管的最优工作状态一直是国内外的研究热点。本文针对已有相关研究的不足,提出了一种基于Advanced Design System(ADS)电路仿真软件获取微波整流电路中整流二极管阻抗的方法。该方法基于单管并联整流电路的理想模型,通过“阻抗获取-阻抗匹配”的迭代过程,得到该电路结构下对应于最优整流性能时的二极管阻抗收敛值。该方法操作流程简明,计算量较小,结果较准确。根据该收敛阻抗,本文设计了一种单管并联验证电路,把输入滤波器和直流滤波器共有的高次谐波抑制部分整合到二极管支路,使得整体结构更为紧凑,总体插入损耗更小。实测结果与仿真结果较为吻合,在输入功率为8. 3 dBm,直流负载为1300 Ω时,电路实测输出电压为2. 469 V,整流效率可达69. 36%,在输入功率为-1. 6 ~11. 4 dBm 的范围内,整流效率均在50%以上。     

高效平面印刷毫米波段整流电路设计与实验

利用微带线设计了一种Ka波段毫米波整流电路.整流电路由输入阻抗匹配网络、整流二极管及输出直通滤波器构成,输入端口为50 Ω微带线,便于实验及与天线集成.利用等效电路模型理论分析了肖特基二极管在Ka波段的整流特性,设计并加工电路.实验测得,在32.5 GHz工作频率和20 dBm输入功率下,整流电路在350 Ω负载上获得57％的毫米波直流(MMW-DC)转换效率;在输入功率大于8 dBm时,整流效率均大于30％.该整流电路采用传统的印制电路板(Printed Cireuit Board,PCB)制作工艺,具有造价低和易集成等优点,且整流效率高,可应用到毫米波无线输能系统中.     

一种高效的大功率宽带整流电路

提出了一种由π型匹配枝节、整流二极管、直通滤波器组成的高效大功率宽带整流电路。采用2只HSMS-282P肖特基二极管桥设计单级倍压整流电路,使电路在整流效率不下降的情况下提升输入的功率容量;采用π型匹配枝节实现阻抗匹配,使电路具有宽频特性,同时其并联短路枝节可以作为输入滤波器,实现小型化和整流效率的提高。直通滤波器用于抑制基频和二极管非线性产生的高次谐波,以提高整流效率。实测结果表示：在2.05~2.6 GHz带宽内整流效率大于60%;在2.45 GHz工作频率和35 dBm输入功率下,整流电路在330 Ω负载上获得70%的整流效率。该整流电路具有整流效率高、功率容量大、频带宽的特性,可为工程人员设计大功率微波整流电路提供设计指导。     

一种915MHz紧凑型肖特基二极管微波整流电路

为了提高射频标签(RFID)中基于肖特基二极管微波整流电路的效率,采用微带结构实现了一种915 MHz紧凑型的整流电路。该微波整流电路具有质量轻、尺寸小、整流输入功率动态范围大等特点,设计的仿真和实验结果显示:输入微波功率在13 dBm~22 dBm的情况下,均获得了高于60%的整流效率。通过完善改进电路,可以进一步提高整流的效率,并应用于微波无线能量传输或大型RFID的微波整流天线。     

一种2.45 GHz微波二极管整流电路

为了提高用于微波无线功率传输的微波整流效率,本文采用微带结构实现了一个2.45 GHz的微波二极管整流电路.仿真实验结果证明在输入功率约为20 dBm的情况下,获得了大于50%的整流效率.通过完善和改进电路,可以进一步提高整流的效率,并应用于微波整流天线.     

一种用于无线输能的2.45 GHz微带贴片整流天线

为了提高大信号输入下整流天线的整流效率,利用Ansoft Designer仿真软件,设计制作了一种工作在2.45 GHz的微带整流天线,接收天线采用二元串联微带矩形贴片阵列,单元贴片之间引入两个短枝节以调节方向图指向;整流电路采用二极管串联双管倍压电路。实验结果与仿真结果二者吻合良好,实测得到输入功率为100 mW时,微波-直流转换效率达到64%,同单管并联电路相比,大大提高了整流电路的输入功率,使整流天线的实际转换效率更高。     

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.     

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.     

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.     

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.     

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.     

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.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.