应用于能量收集的自启动DC-DC升压转换器

基于SMIC 0.18 μm CMOS工艺,设计了一种应用于能量收集的自启动DC-DC升压转换器。系统包括两级升压结构,第一级自启动模块实现亚阈值电压输入,将电压升至可供第二级主升压结构使用的电压。两级升压结构中,均采用了基于栅交叉耦合的电荷泵,对其中的电荷传输开关进行改进,克服了传统Dickson电荷泵的体效应问题,提高了电压增益和转换效率。仿真结果表明,DC-DC升压转换器能在300 mV输入下实现自启动,输出电压为1.8 V,纹波电压约为4 mV,效率达到69%。     

应用于微弱能量收集系统的超低压自启动电路

采用0.18 μm 1.8 V/3.3 V CMOS工艺,设计了一种应用于微弱能量收集系统的超低压自启动电路。采用LC振荡电路产生2个高频高幅度的时钟信号,将4级交叉耦合电荷泵串联在一起作为升压主电路,避免了器件栅极氧化层不稳定以及器件导通、关断不彻底的问题。仿真结果表明,该低压自启动电路能够在约150 μs的时间内将80 mV的直流电压升压到579 mV,转换效率达80%。相比其他低压启动电路,该低压自启动电路能在不借助外部辅助的条件下实现低压自启动,具有更快的启动速度和更高的效率。     

基于环境微弱能量收集的低阈值CMOS电路设计

环境中存在着丰富的电磁波能量,而人体运动产生的机械能则是一种不受外界干扰非常稳定的能源,这些能源的存在使设备为自身供电成为可能.由于射频电磁波能量和振动能量密度低的特性,设计了一种能够匹配低功耗低电压的复合能量收集与管理电路.该电路采用0.18 μm标准CMOS工艺,对电源转化模块、电源调节模块(整流电路、滤波电路、升压电路,以及为升压电路提供时钟信号的振荡电路)和储能模块进行了分析与设计.整流电路的最低输入电压为200 mV,整流效率达到75％.升压电路采用新型电荷泵电路,具有4.8倍升压效果,输出电压最高达到970 mV,电压纹波率为0.5％.当输入电流为50 μA时,该电路转换率为10％,输出平均功率为1.14μW.     

应用于弱能量收集的低功耗DC-DC升压转换器

设计了一种应用于能量收集领域的低功耗、超低电压DC-DC升压转换器。研究了转换器工作频率与功率和效率的关系,通过选择合适的脉冲宽度调制(PWM)频率来提高输出功率。通过适当提升转换器开关功率管的栅极电压,减小了晶体管的泄露电流,从而提高了输出电压。基于CMOS 65 nm工艺进行设计。仿真结果表明,提出的方案能提高弱能量转换效率。当输入电压为100 mV时,最大输出电压为1 000 mV。DC-DC升压转换器的输出功率为3.08 μW,转换器控制单元的功耗为697 nW,转换效率达到57.3%。     

应用于能量收集中的接口电路的设计

针对从周围环境中收集能量的微型发电机输出功率和电压非常小,无法直接应用的问题。文中设计了一种超低输入电压、低功耗且高效的接口电路。该接口电路包含两级,第一级是无源级和仅由一个有源二极管组成的第二级。为降低有源二极管的功耗,采用一个工作在亚阈值区的衬底输入比较器用来驱动MOS开关。设计采用TSMC 018 μm 标准CMOS工艺,使用Cadence Spectre在室温的条件下进行仿真。结果表明,在输入电压为500 mV（100 Hz）,负载电阻为50 kΩ时整流器的电压转换率为977%,能量转换率为913%。整流器能够在输入电压振幅为320 mV以上实现高效整流。     

适用于能量收集系统的低功耗迟滞比较器

根据微弱能量收集系统的应用需要,设计了一种宽电压范围的折叠式低电压、低功耗迟滞比较器。在比较器输入级、输出级分别利用偏置电路和内部节点对尾电流管进行偏置,实现了根据现场工作电压的变化自动调节尾电流,达到降低功耗、加快输出响应速度的目的。基于0.18 μm CMOS工艺进行设计。仿真结果表明,该比较器在0.8~1.2 V电源电压范围内正常工作,迟滞电压在15~70 mV范围内可调,最低功耗为0.15 μW。     

一种基于自适应电荷泵的多源能量收集芯片

采用标准0.18 μm CMOS工艺,设计了一种可以同时高效收集压电、光电、热电、射频能量的多源能量收集芯片。该收集芯片由多种能源接口电路、可重构电荷泵和自适应控制电路等单元构成。可重构电荷泵中,通过调节电压转换倍率和开关工作频率来降低电荷再分配损耗,提高了转换效率,扩大了输入电压范围。自适应控制电路中,采用固定导通时间法控制系统的输出电压,所产生的峰值电压被复用,并用来控制电荷泵的工作状态,降低了电路的复杂度和功耗。仿真结果表明,该收集芯片的整体动态功耗为33 μW,能量转换效率最高为60.3%。版图尺寸为1 672 μm×1 990 μm。     

一种低压快速瞬态响应的片上LDO

提出了一种低输入电压的快速瞬态响应片上低压差线性稳压器(LDO)。采用基于反相器的轨-轨输入运放作为误差放大器(EA)的输入级。EA后级采用大抽灌电流能力的STCB结构。LDO加入了高通耦合结构,实现了低输入电压和全负载范围下的快速瞬态响应。该LDO无需外加偏置网络就能实现自启动。在Dongbu 0.5 μm CMOS工艺下,LDO的输入电压为2.2~2.7 V,输出电压为2 V。仿真结果表明,在负载电容为100 pF、压差为200 mV的条件下,该LDO可稳定输出0.1~100 mA的负载电流,负载在0.5 μs范围内切换时的电压尖峰在310 mV以内。     

用于射频能量收集的低阈值CMOS整流电路设计

基于TSMC 180 nm工艺,设计了一款高效率低阈值整流电路。在传统差分输入交叉耦合整流电路的基础上,提出源极与衬底之间增加双PMOS对称辅助晶体管配合缓冲电容的改进结构,对整流晶体管进行阈值补偿。有效缓解了MOS管的衬底偏置效应,降低了整流电路的开启阈值电压,针对较低输入信号功率,提高了整流电路的功率转换效率(PCE)。同时将低阈值整流电路三级级联以提高输出电压。测试结果显示,在输入信号功率为-14 dBm@915 MHz时,三级级联低阈值整流电路实现了升压功能,能稳定输出1.2 V电压,峰值PCE约为71.32%。相较于传统结构,该低阈值整流电路更适合用于射频能量收集。     

一种用于极性反转热电能量收集的升降压转换器

针对传统TEG能量收集系统输入电压单一化与可用功率范围较窄的问题,提出了一种适用于极性反转热电能量收集的升降压DC-DC转换器。采用双极性输入升降压拓扑结构,能够自适应收集双极性输入热电能量,并增加储能升降压回路,有效拓宽了重载下可用功率范围,保证输出电压稳定性,并在轻负载时收集多余能量,显著提高轻载转换效率,保证系统续航能力。最大功率追踪方法采用结构简单、追踪效率较高的开路电压法。180 nm CMOS工艺仿真验证表明,所提出的能量收集系统轻重负载条件下转换效率均高于85％,最高转换效率为93.26%(VTEG=500 mV,RS=210 Ω),最大功率追踪效率达到99.52％(VTEG=-600 mV),电路最低工作输入电压为±25 mV,且重负载下1.8 V输出电压纹波小于30 mV。     

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.     

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.