一种可植于软件无线电的低功耗可编程增益放大器

本文提出了一种新的技术,用于优化可编程增益放大器的带宽和功耗的关系。这个可编程增益放大器由三级级联的放大器组成,每一级放大器包括可变增益放大器和直流失调电压消除电路。在消除直流失调的电路中,高通的截止频率可从4 kHz到80 kHz变化。可编程增益放大器芯片使用0.13微米的工艺加工,测试结果表明增益可以从-5dB到60dB连续可调。在 60dB增益模式下,当带宽可从1MHz到10MHz变换,电路消耗的功耗为0.85mA到3.2mA,电源电压为1.2V。它的带内OIP3值为14dBm。     

一种带新型直流失调补偿电路的模拟数字控制可配置的自动增益控制器

本文提出一种可用于零中频接收机的模拟/数字控制可配置的自动增益控制环路的设计,应用一种新型的直流失调消除电路。这种自动增益控制环路可配置于模拟或者数字控制,以便与不同的基带芯片兼容。本文更进一步提出了一种新型的直流失调消除电路,这种直流失调消除电路实现了低于10KHz的下限截止频率（HPCF,high pass cutoff frequency）。自动增益控制环路电路采用0.18um CMOS工艺。当配置于模拟控制模式下,这种自动增益控制环路的增益动态范围为70dB,3dB带宽大于60M。当配置于数字控制模式下,通过5比特的数字控制码控制,这种自动增益控制环路的增益动态范围为64dB,步进精度2dB,步进误差小于0.3dB。当输入引入40mV直流失调,电路输出直流失调电压小于1.5mV。电路整体功耗小于3.5mA,面积800um*300um。     

一种应用于IEEE 802.11 b/g/n无线局域网收发机的CMOS模拟基带电路

本文提出了一种应用于直接变频无线局域网收发机的模拟基带电路,该电路采用标准的0.13微米CMOS工艺实现,包括了采用有源RC方式实现的接收4阶椭圆低通滤波器、发射3阶切比雪夫低通滤波器、包含直流失调消除伺服环路的接收可变增益放大器及片上输出缓冲器。芯片面积共1.26平方毫米。接收基带链路增益可在-11dB至49dB间以2dB步长调节。相应地,基带接收输入等效噪声电压（IRN）在50 nV/sqrt(Hz) 至30.2 nV/ sqrt(Hz)间变化而带内输入三阶交调（IIP3）在21dBm至-41dBm间变化。接收及发射低通滤波器的转折频率可在5MHz、10MHz及20MHz之间选择以符合包含802.11b/g/n的多种标准的要求。接收基带I、Q两路的增益可在-1.6dB至0.9dB之间以0.1dB的步长分别调节以实现发射IQ增益失调校正。通过采用基于相同积分器的椭圆滤波器综合技术及作用于电容阵列的全局补偿技术,接收滤波器的功耗显著降低。工作于1.2V电源电压时,整个芯片的基带接收及发射链路分别消耗26.8mA及8mA电流。     

带有DCOC结构的中频可编程增益放大器

介绍了一种用于射频识别接收机、能有效消除直流失调的中频可编程增益放大器.单级放大器的仿真结果可提供.10～20 dB的增益控制范围,增益步长为2 dB,增益误差小于0.3 dB.通过在直流失调消除环路中增加一级滤波器的方法,有效地降低了直流失调和低频噪声,在40 kHz工作频率下等效输入噪声电压38.04 nV/ Hz,直流失调消除电路可将输出直流失调量抑制在输入失调量的2%范围以内.电路采用0.18μm IP6M CMOS工艺实现.     

一种应用于直接变频WLAN接收机带数字辅助直流失调消除功能的可变增益放大器

本文提出了一种包含数字辅助直流失调消除(DCOC)功能,应用于直接变频无线局域网接收机的可变增益放大器(PGA)电路。该PGA采用0.13微米标准CMOS工艺实现,芯片面积0.39平方毫米,在1.2伏电源电压下的功耗为6.5毫瓦。通过采用单环路单数模转换器(DAC)混合信号直流失调消除结构,直流失调消除的最小建立时间减小至1.6微秒,同时可变增益放大器的增益能够在-8分贝到54分贝间以2分贝的步长变化。该直流失调消除环路采用了一种分段式数模转换器以在不牺牲精度的前提下降低设计复杂度,并采用了特定的数字控制算法使得环路的直流失调消除响应时间能够在快慢两种模式间动态切换,以使可变增益放大器符合无线局域网应用的要求。     

一种新颖的可应用于多模多频接收机可配置的可变增益放大器

本文阐述了一种新颖的可应用于多模多频接收机射频前端可配置的可变增益放大器的设计方法。可变增益放大器包括增益放大电路,控制电路,直流失调消除电路和模式转换电路四个部分。这种结构可以在保证多模多频应用的前提下通过硬件复用最大化来节省芯片面积和功耗。电路采用0.18 um CMOS 工艺,在1.8V的供电电压下可实现5dB 至87dB的动态范围,电路的带宽（所有增益下）大于80 MHz。此外,直流失调消除电路有效抑制了直流失调成分至小于40mV。整个电路的功耗小于3mA,面积为705um*100um。     

一种低功耗混合信号直流失调消除电路

设计了一种应用于直接变频接收机的低功耗混合信号直流失调消除(DCOC)电路。该电路采用混合信号的方式消除直流失调电压,避免了传统模拟域直流失调消除系统环路响应速度与高通带宽之间的折中,具有功耗低、建立时间快、面积小等优点。采用该DCOC后,直接变频接收机的输出剩余直流失调电压小于37mV,直流失调消除环路的建立时间小于200μs。电路采用0.13μm CMOS工艺实现,芯片尺寸为0.372mm×0.419mm,工作于1.2V电源电压时,消耗电流仅为196μA。     

两个重要改进提高了RFID读写器的性能

基于无源电子标签的RFID读写器系统通常采用所谓“零中频”接收方案,采用该方案会造成射频信号发射端和接收端之间的载波泄漏,其结果是一方面接收机前端容易饱和因而减少了系统通信距离;另一方面会带来所谓的“直流偏移”问题从而增加了系统误码率．本文提出了两个措施来解决或改善这一问题．首先,将载波抵消技术应用到2.45 GHz频段的RFID读写器中,采用微带电路进行载波泄漏抵消电路的设计,通过ADS软件仿真、制作并测试样机,文中给出了改进后环行器泄漏功率的抵消结果．其次,提出一种带有直流反馈环路的宽带高增益直流放大器,用于放大基带信号并自动补偿混频器带来的直流分量,输出波形无明显失真,从而降低了读写器读取电子标签数据的误码率．     

用于UHF RFID阅读器的自动频率校准模拟基带

基于0.18μm标准CMOS工艺,提出了一种适用于超高频射频识别阅读器的自动频率校准模拟接收基带。该模拟基带包含直流偏移消除电路和信道选择滤波器,直流偏移消除电路有6dB的预增益,信道选择滤波器采用8阶巴特沃斯结构。在频率校准电路的作用下,滤波器能够分别对250kHz和1.35MHz截止频率进行校准,校准时间小于3μs。后仿真结果表明,在3.3V电源电压下,整个模拟基带消耗12mA电流,截止频率为1.35MHz,10dB增益条件下带内输入3阶交调达到12dBm,在30dB增益时,带内噪声系数为26dB。     

用于77GHz毫米波雷达的模拟基带电路设计

实现了一个带宽和增益可配置、高线性度、低噪声的模拟基带电路,可应用于77 GHzCMOS毫米波雷达接收机.电路包括一个带宽可配置的5阶巴特沃斯低通滤波器模块、三个可编程增益放大器模块以及三个直流失调消除环路.增益范围为18～70 dB,增益步进为6 dB;带宽为200 kHz～2 MHz;噪声系数最小为24 dB;输出1-dB压缩点为5.1 dBm,在最高增益时,IIP3为-52dBm;功耗为14.6 mA@1 V.电路采用65 nm CMOS工艺实现,芯片面积为1.2×0.93 (mm2).     

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.