用于GaAs射频集成电路的不同厚度氧化铝MIM 电容的研究

本文研究了不同厚度的氧化铝对MIM电容直流和射频特性的影响。在1MHz下,对于20nm氧化铝MIM电容,其拥有3850 pF/mm₂的高电容密度和可接受的681 ppm/V₂的VCC-α电压系数。1MHz时突出的74 ppm/V₂VCC-α电压系数,8.2GHz谐振频率以及2GHz时41的Q值可以从100nm氧化铝MIM电容获得。采用GaAs工艺以及原子层淀积制造的高性能ALD氧化铝MIM电容很有可能成为GaAs射频集成电路很有前景的候选器件。     

有效跨导为1052 mS/mm的高性能InP基In0.52Al0.48As/In0.53Ga0.47As HEMTs

我们成功研制了栅长为0.15 μm、栅宽为2?50 μm、源漏间距为2 μm 的InP 基In_0.52Al_0.48As/In_0.53Ga_0.47As高电子迁移率器件。室温下,当器件V_DS为1.7 V,V_GS为0.1 V时,其有效跨导达到了1052 mS/mm。传输线方法(TLM)测试显示器件的接触电阻为0.032 Ω.mm,器件欧姆接触电阻率为1.03?10_-7Ω.cm_-2. 正是良好的欧姆接触及其短的源漏间距减小了源电阻,进而使得有效跨导比较大。器件还有比较好的射频特性：当V_DS＝1.5 V, V_GS ＝0.1 V 时,f_T和f_max分别为151 GHz,303 GHz。文章报道的HEMT器件非常适合毫米波段集成电路的研制。     

基于非线性标准差模型的差分光学吸收光谱技术烟气浓度测量

采用差分光学吸收光 谱(DOAS)技术测量烟气时,需采用非线性补偿方法来提高测量精度。本文基于自行研制的DO AS技术烟气测量系统,对SO₂和NO标准气体进行了单一气体的建模实验,提出了利用 差分光学密度标准差和气体浓度之间关系的非线性模型预测烟气浓度的方法,并以此测量 了SO₂和NO单一组分及混合气体的浓度,将实验结果与传统最小二乘法的反演浓度进行 了对比。结果显示,测量单一气体时,得到的两种气体非线性模型的判定系数 R²分别为 0.999和0.999,SO₂的满量程误差为±0.7％,最大误差为 2.6%和2.8%,明显优于最小 二乘法反演最大误差－16.1%和－19.9%;测量混合气体时,最大误差 由传统方法的－24.6%和－28.1%减小至－4.8%和5.2%。结果表明,本文方法可提高烟气测量的准确度。     

一种使用|VGS|和ΔVBE的CMOS电压基准的曲率补偿方法

本文为CMOS电压基准源提出一种新型的混合曲率补偿方法。该方法使用了曲率互补的两种亚基准。第一种亚基准是工作于饱和区的PMOS晶体管的源栅电压|V_GS|_p,另一种亚基准是由工作于亚阈值区的NMOS晶体管的栅源电压|V_GS|_n 以及两个三极管的基级-发射极电压之差ΔV_BE组成。由该方法生成的电压基准源温漂系数低、占用面积小。该方法经0.18 um CMOS工艺验证。测试结果显示,从-40°C 到 120°C,未经校正的基准源温漂系数低至12.7 ppm/°C,而仿真结果则低至2.9 ppm/°C;室温下该电路消耗50 uA的电流;电源抑制比是-31.2 dB@100kHz ;芯片面积为0.045mm₂。     

非对称In0.53Ga0.47As/In0.52Al0.48As量子阱的零场自旋分裂能与高场g因子

我们研究了非对称In_0.53Ga_0.47As/In_0.52Al_0.48As量子阱中二维电子气的磁输运性质,所测量的样品的径向磁阻Rxx的Shubinikov-de Haas振荡没有呈现出拍频的特征。通过测量样品的弱局域效应提取了其零场自旋分裂能并通过对自旋分裂的Rxx双峰间距随倾斜角度theta的依赖关系的拟合提取了高场下的有效g因子。样品的Dingle plot图呈现非线性和特征,这可以归因于来自样品衬底附近的掺杂Be原子的长程势散射效应。     

BaSm0.2Ti(4+x)O(9.3+2x)微波介质陶瓷的研究

该文采用固相法制备了BaSm_0.2Ti_(4+x)O_(9.3+2x)(x=0~0.6为摩尔分数)陶瓷,研究了不同x值对陶瓷相组成、显微结构和微波介电性能的影响。结果表明,在0≤x≤0.6时,随着x的增大,介电常数εr变化较小,品质因数与频率之积(Q×f)和频率温度系数τf均随x的增大而减小。当x=0.5时,可获得介电性能优异的BaSm_0.2Ti_(4+x)O_(9.3+2x)陶瓷:ε_r=46.9,Q×f≈18 237 GHz,τf≈2.2×10^-6/℃。     

WO3对Rubrene/C70有机太阳能电池性能的改善

研究了WO₃对Rubrene/C₇₀有机太阳能电池 (OSCs)性能的 改善,制备了结构为ITO/WO₃/Rubrene/C₇₀/BCP/Al的OSCs,其中WO₃插入在I TO和Rubrene中间作为阳极修饰层。通过优化WO₃的厚度,研究了WO₃对OSCs性能的改善及其作用机理。实验发现,器件的短路电流Jsc、开路电压V_oc、 填充因子(FF)、光电转换效率(PCE)和串联电阻Rs等性能参数随WO₃厚度的变化呈规律性变化;当 WO₃厚度小于80 nm时,器件PCE随着厚度的增加不断增大;当W O ₃厚大于80 nm时,器件PCE随着厚度的 增加不断减小;当WO₃厚度为80 nm 时,器件PCE达到最高为1.03%, 相应的J sc、V_oc、FF分别为2.81mA·cm－2、 0.83V、43.85%,Rs为45.3Ω·cm²,对比没有WO₃修饰层, 器件的J_sc、V_oc、FF和PCE分别提高了31%、137%、17%,Rs降低了33%。     

双光场作用下里德堡原子吸收特性的研究

光和物质相互作用的过程可通过密度矩阵方程理 论描述。本文基于光和物质相互作用的密度矩阵方程 理论,模拟研究了双光场作用下梯形三能级里德堡原子系统的吸收特性,发现只有耦合、探 测场强度小于 临界值时,探测吸收呈现共振增强的特性,吸收峰值随着耦合、探测场的增强而增大,当场 强度等于临界 值时,共振吸收达到最大;吸收线宽随探测场增强而增大。场强大于临界值时,吸收峰值减 小,之后随着 场强的进一步增大,探测吸收峰分裂为相对于共振频率对称的双峰结构,双峰间隔随场的增 强而增大,这 归因于强场导致的能级分裂,场强越大,能级分裂间隔越大。双峰位置与EIT系统不同,不 再满足Δ_p＝Ω_c/2。 耦合场越大,双峰位置越接近Δ_p＝Ω_c/2。随着耦合场 的增强,弱探测场时双峰峰值缓慢增大,而强探测场时,双峰峰值缓慢减小。     

一种全速率线性25Gb/s时钟数据恢复电路

面向高速光通信系统的应用,提出了一种全速率线性25Gb/s时钟数据恢复电路(Clock and Data Recovery Circuit,CDRC)。CDRC采用了混频器型线性鉴相器和自动锁频技术来实现全速率时钟提取和数据恢复。在设计中没有使用外部参考时钟。基于45nm CMOS工艺,该CDR电路从版图后仿真结果得到:恢复25Gb/s数据眼图的差分电压峰峰值V_pp和抖动峰峰值分别为1.3V和2.93ps;输出25GHz时钟的差分电压峰峰值V_pp和抖动峰峰值分别为1V和2.51ps,相位噪声为-93.6dBc/Hz@1MHz。该芯片面积为1.18×1.07mm²,在1V的电源电压下功耗为51.36mW。     

基于多模激光关联光谱的甲烷气体检测技术

为提高多模激光吸收光谱的灵敏度,将多模二极 管激光关联光谱、长程吸收技术和波长调制光谱结合,建立了一 套具有高检测灵敏度和高稳定性的气体检测系统。采用1675nm多模激光器作为光源,以光程为100 m的离散镜片型 多通 池作为气体吸收池,利用甲烷的2ν₃泛频带吸收谱线,通过计 算待测气体和参考气体的二次谐波信号峰值之间的关系,实 现了对CH₄气体的测量。实验在室温和20.265 kPa(即0.2个标准大气压)条件下进行 ,CH₄浓度范围为1.00×10－5－1.10×10－2。实验结果表明,CH₄浓度测量值与真实值之间具有良好的线性关系, 其线性度为0.997,系统的测量准确度为 3.50%,对浓度为2.60×10－6的气体样 品在30 min内的连续测 量表明系统稳定度优于2.53%。本方法具有操作简单、稳定性 好、灵敏度高和环境适应性强等优点,在工业过程控制和环境监测中具有广阔的应用前景。     

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.     

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.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks     

Call for Papers—Feature Topic,Vol.12,No.7,2015

正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first     

JOURNAL OF ELECTRONICS(CHINA)

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NEXT GENERATION WIRELESS NETWORKS–ESPECIALLY THE USE OF MILLI-MICROWAVE BANDS

The global bandwidth shortage of wireless communications has motivated the exploration of the naillimeter wave （ram-wave） frequency spectrum for the next generation wireless communications. Recent advances in RF CMOS technology and high speed baseband signal processing technologies have enabled tile extensive research and development of turn-wave wireless communications. The multi gigabit per second data rate of ram-wave system will lead to applications in many important scenarios, such as WPAN, WLAN,back-haul for cellular system. And the frequency bands include 28 GHz, 38 GHz, 45GHz, 60GHz, E-BAND and even beyond 100 GHz. The propagation and the imitation of the RF circuits design in these frequency bands make the directional antennas be inevitable for mm-wave communications.