一种用于Bluetooth发接器的倍频式VCO

介绍了一种适用于 Bluetooth发接器的 ,可以单片集成的倍频式压控振荡器 ( VCO)。这种 VCO由两部分组成 ,主 VCO的振荡频率是所需本振频率的一半 ,然后采用“注入锁频”原理对主 VCO的振荡频率进行倍频以产生本振信号。主 VCO和倍频电路都使用了片上集成螺旋电感 ,调谐用的变容元件使用 PMOS晶体管实现。经过版图设计和后仿真 ,在 TSMC0 .35 μm数字 COMS工艺 ,3.3V电源电压下 ,该 VCO在 2 .4GHz中心频率附近可以达到的相位噪声指标为 -1 2 5 d Bc/Hz( 60 0 k Hz) ,在输出摆幅为 60 0 m Vp- p时 ,功耗为 2 2 m W。     

用于以太网物理层时钟同步PLL的VCO设计

研究了一种基于以太网物理层时钟同步的高带宽低噪声压控振荡器（VCO）,该VCO采用交叉耦合的电流饥饿型环形振荡器,通过级联11级环路电路和改善其控制电压变换电路,优化了VCO的输出频率范围以及降低了输出时钟的相位噪声,完全满足以太网物理层芯片时钟电路的性能指标。基于TSMC3．3V0．25μmCMOS工艺的仿真结果表明,中心频率为250MHz时,压控增益为300MHz／V,其线性区覆盖范围是60～480MHz,在偏离中心频率600kHz处的相位噪声为-108dBc。     

数字可编程的VCO

图1的电路是一种窄频带的VCO(压控振荡器),它具有设定数字以决定中心频率的可编程功能,其中心频率比(高频/低频)大于2:1。若对VCO再二分频,就可获得多种的振荡频率。该VCO的工作频率可大于230MHz(采用ECL器件),所以该电路可为用户提供高速的选通和禁止功能。     

新型无绳电话机频率合成器介绍及检修

频率合成器在无绳电话机中,主要为接收电路中的第一混频器提供第一本振频率;为发射电路中的调制器提供调制基准频率,同时发射机的调制信号又加入到频率合成器电路中的VCO部分,与VCO共同组成调频振荡器。     

一种高性能全差分双环路VCO的设计

设计了一种基于SMIC 0.18μm RF 1P6MCMOS工艺的高性能全差分环形压控振荡器(ring-VCO),采用双环连接方式,并运用交叉耦合正反馈来提高性能。在1.8V电源电压下对电路进行仿真,结果表明:1)中心频率为500MHz的环形VCO频率调谐范围为341～658MHz,增益最大值Kvco为-278.8MHz/V,谐振在500MHz下VCO的相位噪声为-104dBc/Hz@1MHz,功耗为22mW;2)中心频率为2.5GHz的环形VCO频率调谐范围为2.27～2.79GHz,增益最大值Kvco为-514.6MHz/V,谐振在2.5GHz下VCO的相位噪声为-98dBc/Hz@1MHz,功耗为32mW。该VCO适用于低压电路、高精度锁相环等。     

具有数字化可编程中心频率的VCO

图1所示的电路为窄带电压控制振荡器(VCO),其数字化可编程中心频率比率大于2:1。利用这种中心频率比率(F_(HIGH)/F_(LOW))大于2:1的VCO,通过简单的二进制除法,就能得到任何输出频率。VCO具有极高的频谱纯度,当使用高性能ECL时,典型的性能可大于230MHz。并且几乎能够瞬时启动和瞬时停止振荡。     

面向配网运行状态在线监测的VCO设计

文中提出了一种新型的5.17GHz CMOS压控振荡器(VCO),该VCO采用提高品质因子Q的电容反馈技术。该VCO能够在不需要额外衬底偏置电压的前提下,在高频段降低电路的寄生效应,并且电容反馈技术改善了电路的相位噪声,同时采用不需要衬底偏置电压的自衬底偏置技术降低了电路的功耗。测试结果表明,该VCO振荡频率带宽为4.66GHz~5.87GHz,具有22.98%的调谐率;在0.8V电压供电下,电路消耗了3m W的功耗;在1MHz偏移频率处取得了-127.8d Bc/Hz的相位噪声。该VCO的品质因数Fo M达到-197.3d Bc/Hz。     

低功耗自适应跨导-电容带通滤波器电路实现

采用单层多晶硅3.3V,0.35μm CMOS数字工艺,实现了用于蓝牙系统的自适应带通滤波器,其中心频率为2MHz,带宽为1.2MHz,功耗为12mW.并对滤波器PLL自适应电路中压控振荡器(VCO)的谐振条件进行了研究,分析了VCO中运放寄生参数对谐振频率的影响.同时,用一种简单的跨导运放结构作为VCO中的负阻抗,解决了VCO振荡幅度限幅问题.     

GPS接收机中1.57GHz CMOS锁相环的设计

设计了一种用于GPS接收机中采用CMOS工艺实现的1.57GHz锁相环.其中,预分频器采用高速钟控锁存器(LATCH)的结构,工作频率超过2GHz.VCO中采用LC谐振回路,具有4段连续的调节范围,输出频率范围可以达到中心频率的20%.电荷泵采用一种改进型宽摆幅自校准电路,可以进一步降低环路噪声.锁相环采用0.25μmRFCOMS工艺实现.测量表明VCO输出在偏移中心频率1MHz处的相位噪声为-110dBc/Hz,锁相环输出在偏移中心频率10kHz处的相位噪声小于-90dBc/Hz.供电电压为2.5V时,功耗小于15mW.     

PLL调频立体声接收机制作

锁相环(PLL)电路PLL(锁相环)电路的基本组成如图1。压控振荡器(VCO)是一种用电压控制振荡频率的电路。假定基准振荡器的频率为100kHz,若要构成一个700MHz 的PLL 路,VCO 的输出需经过分频系数 N=700的分频器。也得到一个100kHz 的信号,若两者完全相同,比较器输出的 VCO 的控制电压不变,就能得到稳定的70MHz 的输出。由于某种原因使频率发生变化,经比较器和 LPF 输出的电压产生高低变化,对 VCO 的振荡频率起到补偿作用,使振荡稳定。若频率增高,加在 VCO 上的电     

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.