一种全集成的麦克风可编程增益放大器设计

针对麦克风应用,设计一种全集成、高精度的可编程放大器电路。该电路采用电容增益以及高通滤波器的设计方法,无须片外去耦合电容,实现可编程增益放大器的单片集成。可编程增益放大器电路采用SMIC 0.13μm 1P8M CMOS工艺实现。完成后仿真结果表明,在电源电压1 V,增益18 dB,输入信号频率2 kHz,峰峰值50 mV时,可编程增益放大器动态范围达到73 dB,总谐波失真64 dB,整体功耗206μW,满足麦克风全集成、高精度的应用需求。     

用于IRFPA ROIC的高性能缓冲器模块的设计

红外焦平面读出电路(IRFPA ROIC)主要用于焦平面阵列与后续信号处理之间的通信.文章提出了一种用于红外焦平面读出电路的缓冲器模块,包括列缓冲器、高性能的输出缓冲器以及相应的偏置电路.缓冲器均采用单位增益放大器结构,通过放大器的优化设计可实现对不同负载的有效驱动且静态功耗较低.该缓冲器模块用于一款640×512面阵、30μm中心距的中波红外焦平面读出电路,采用CSMC 0.5μm DPTM工艺进行流片加工.仿真结果表明,列缓冲器的开环增益为40.00 dB,单位增益带宽为48.17 MHz(10 pF).输出缓冲器可实现轨到轨的输入,开环增益为39.68 dB,单位增益带宽为46.08 MHz,读出速率高达20 MHz,功耗为16.02 mW(25 pF//5.1 kΩ).该模块输入端拉出的测试管脚可在焦平面读出电路的晶圆测试中帮助验证芯片功能.通过调节测试端口,测试结果与仿真结果大体一致,验证了该缓冲器模块的设计可行.     

一种用于天文望远镜的低噪声CCD读出电路

设计了一种用于天文望远镜的低噪声电荷耦合器件(Charge Coupled Devices,CCD)读出电路.该读出电路主要包括电容增益电路、单端转差分电路、双斜率积分电路以及缓冲器电路.CCD读出电路采用SMIC 0.18μm1P6M CMOS工艺实现.后仿真结果表明,在电源电压3.3V,输入信号67kHz,输出信号80mV峰值时,输出信号动态范围86dB,等效输入噪声2.523nV/Hz1/2,整体功耗1.25mW.     

一种可配置的电容-电压转换电路

提出了一种检测微小电容信号的可配置的电容-电压转换电路。该电路由电容补偿电路、电荷积分电路、采样保持电路、低通滤波和缓冲器组成。使用调制解调的电容检测方法,实现了电容-电压转换。仿真结果表明,电容分辨率为1.70aF/√Hz,输出电压信号与电容差成正比,确定系数R²为0.999 99。电路中的积分电容值、放大增益、补偿电容和带宽均可以通过编程灵活设定。该电容-电压转换电路可用于MEMS及其他电容式传感器。     

一种宽动态范围跨阻放大器的设计

针对光电探测器的光电流信号弱、变化范围大的特点,设计了一种全新的检测光电流信号的跨阻放大器(TIA)电路结构,其检测电流信号范围为1.6 μ上A～1.6 mA,动态电流检测范围达到60 dB.通过在电路内部设计出两个增益可调、增益段不同的TIA,分别处理光电流的小电流段(1.6～50 μA)和大电流段(50 μA～1.6 mA),增益可调范围为56～96 dBΩ;通过外置输出电压饱和检测信号,选择所需工作的TIA及其增益段.该电路采用0.18 μm标准CMOS工艺的PDK进行电路设计、版图设计和仿真验证等.测试结果表明:在检测电流为1.6 μA时,输出电压为95 mV;检测电流为1.6mA时,输出电压为915 mV,与仿真结果相一致.电路瞬态特性良好,上升时间为5～10 ns,3.3V电压下功耗小于2 mW,各指标满足设计要求.     

一种低电压低功耗Class-AB运算跨导放大器

提出了一种新型Class-AB全差分运算跨导放大器(OTA).该OTA基于一种结构简单的电压缓冲器,在大信号非线性工作时,能够输出不受静态偏置电流限制的瞬态电流,提高了摆率和建立速度;同时,该结构还能够增强直流增益、增益带宽积等小信号特性,适合于低功耗开关电容电路的应用.另外,该OTA结构简单,适合于低电压工作.采用0.18μm CMOS工艺进行仿真,结果表明,该OTA结构能够在1V电源电压下工作.     

一种用于红外焦平面读出电路的输出缓冲器

设计了一种应用于红外焦平面读出电路的输出缓冲器,其建立时间短、静态功耗低、线性度高,在77 K和300 K温度下均能正常工作.该输出缓冲器采用0.5 μm CMOS工艺,5.5 V单电源供电,负载为一个25 pF电容并联一个500 kΩ电阻.模拟结果表明,该输出缓冲器在室温(300 K)时,开环增益为54.2 dB,单位增益带宽20 MHz,建立精度为0.1%时,建立时间为45 ns,静态功耗仅为3.3 mW;77 K时,开环增益为63 dB,单位增益带宽123 MHz,建立精度为0.1%时,建立时间为20 ns,静态功耗仅为3.72 mW.     

一种应用于MEMS麦克风偏置电路的电荷泵设计

MEMS麦克风需要一个高于10 V的偏置电压才能工作,这个高电压一般由内部电荷泵电路产生.在传统Dickson电荷泵结构的基础上,提出一种改进的电荷泵结构.它首先将非重叠时钟的幅度加倍,然后用幅度加倍的时钟作为电荷泵的驱动时钟,取得了明显的升压效果.Hspice仿真结果表明,电源电压为1.4V时,6级二极管-电容升压单元就可以实现10.7674 V的输出电压.与传统的Dickson升压电路相比,改进型电荷泵的升压单元减少了4级,且其核心部分的面积减小了21％,功耗降低了40％(参考SMIC 0.35 μm CMOS工艺).     

基于MEMS的非制冷红外探测器读出电路的设计

基于MEMS的非制冷红外探测器广泛用于军用和民用领域,其中作为探测器核心部件的焦平面探测阵列的读出电路等关键技术的研究至为重要.设计了一块240×320的焦平面探测阵列的读出电路,此电路能够抑制MEMS工艺的波动,减小探测器环境温度的影响.采用HHNEC 0.5 μm 工艺对此设计流片,其测试结果达到预期目标.芯片输出电压为1.5～3.5 V,每帧图像输出时间为16.32 ms,可以保证每秒61帧图像输出.     

基于0.18μm SiGe BiCMOS工艺的25Gb/s宽带可变增益放大器

介绍了一种基于0.18 μm SiGe BiCMOS工艺的,可应用于高速通信的25 Gb/s可变增益放大器(VGA).该放大器由核心电路、输出缓冲器和偏置电路组成,核心电路采用改进型Gilbert结构,增大了电路的增益动态范围;同时采用电感峰化技术克服大寄生电容来实现宽带特性.后仿真结果表明,该可变增益放大器的最大增益为20.15 dB,-3 dB带宽(BW)为26.8 GHz,可支持高达25 Gb/s的数据速率,在3.3 V电源电压下的功耗为26.4 mW,芯片大小为1 120 μm×1 167 μm.     

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.     

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.     

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.     

Influence of polarization extinction ratio on distributed polarization coupling detection

Distributed polarization coupling in polarization-maintaining fibers can be detected by using a white light Michelson interferometer. This technique usually requires that only one polarization mode is excited. However, in practical measurement, the injection polarization direction could not be exactly aligned to one of the principal axes of the PMF, so the influence of the polarization extinction ratio should be considered. Based on the polarization coupling theory, the influence of the incident polarization extinction on the measurement result is evaluated and analyzed, and a method for distributed polarization coupling detection is developed when both two orthogonal eigenmodes are excited.     

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.     

High-quality single-crystal CdSe nanoribbons and their optical properties

Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method, in which two-step-thermal-evaporation is used to control CdSe sources＇ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photolumines-cence indicates that the lasing emission at 710 nm has been observed under optical pumping （266 nm） at power densities of 25-153 kW/cm^2. The full width half maximum （FWHM） of the lasing mode is 0.67 nm     

Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.     

中国建立EB级存储实验室,致力云计算应用(英文)

正With the support of 863 programs,Sugon Information Industry Co.,Ltd.,set up a dawning EB-class storage laboratory to address massive data storage requirements and largescale cloud computing demonstration applications.The Dawning EB-class cloud storage system adopts advanced fault-tolerant architecture,efficient data fault-tolerant algorithms with user authentication and data encryption policies to deal with the"lost""wrong"and"stolen"problems of data for ensuring the reliability and safety of the EB-class storage system in the public network application environments.The Dawning EB-class Storage Laboratory taking advan-