光控相控阵波束接收网络

文中提出了一种基于光纤色散真时延技术的光控相控阵雷达多波束接收网络。该网络制作原理是根据光纤的色散特性,主要由密集波分复用器(DWDM)和光纤延时模块构成。DWDM 实现对多通道光合成,多个光开关和光纤延时环组成的光纤延时模块实现对合成的多路光载波进行延时量调节,从而实现波束扫描。依据原理方案,研制了一套16通道光接收、双波束形成网络,实现从-40°到+45°的16个不同波束指向扫描,切换速度≤30us。暗室测试证明了其波束形成能力。     

超宽带延时幅相控制多功能芯片的设计

针对航空航天和卫星通信等设备的需求,介绍了一款超宽带延时幅相控制多功能芯片。该芯片集成了数字和微波电路,有T/R 开关、5 位数控延时器(10 ps 步进TTD)、5位数控衰减器(1 dB 步进ATT)、2 个行波放大器、均衡器及数字电路。基于GaAs E/D PHEMT 工艺研制出了芯片实物,芯片尺寸为4.5 mm*5.0 mm*0.07 mm。采用微波在片测试系统对该幅相控制多功能芯片进行了实际测试,在3 ~ 17 GHz 频段内实现了10~310 ps 延时范围,1~31 dB 衰减范围。测试结果显示,发射/接收增益大于2 dB,发射1 dB 压缩输出功率P1 dB_Tx大于12 dBm,接收1 dB 压缩输出功率P1 dB_Rx大于10 dBm,全态输入输出驻波均小于1.7,+5 V 下工作电流130 mA,-5 V 下工作电流12 mA。衰减器全态RMS 精度小于1.4 dB,全态附加调相小于±8°。延时器全态RMS 精度小于3 ps,全态附加调幅小于±1 dB。     

GaAs PHEMT超宽带六位数控延时器芯片

研究了数控延时器(TTD)芯片的基础原理,基于GaAs PHEMT工艺,设计了一款超宽带数控延时器芯片,该芯片具有超宽带、大延时量和小尺寸等优点,主要用于有源相控阵雷达中。微波在片测试系统对该6位延时器芯片实际测试结果显示,在3~17 GHz范围内,延时调节范围为10~630 ps,64态延时均方根(RMS)误差小于8 ps,全态插入损耗小于22 dB,插损波动小于±1 dB,全频带输入输出电压驻波比(VSWR)小于1.7,整个芯片尺寸仅为4.0 mm×2.6 mm×0.07 mm。实测结果与理论仿真结果吻合良好。     

基于微机械工艺的60 GHz波束扫描天线阵

提出了一种应用于高速率无线通信的基于微机械工艺的波束扫描天线阵.基于微机械工艺的空气填充的同轴线结构能提供低损耗的矩形微同轴传输线和馈电网络设计.设计的传输线仿真和测试插入损耗均小于0.18 dB.仿真和测试结果吻合良好.波束扫描天线阵的尺寸为17.5×14.5×0.42 mm3, -10 dB带宽为10 GHz(55~65 GHz), 其带宽覆盖60 GHz标准的全频段.波束扫描角度分别为±35°和±11°.在60 GHz中心频点, 增益分别为11.8 dBi和12.1 dBi.     

一种45°极化的毫米波二维宽带宽角扫描相控阵

设计了一款工作于Ka波段的+45°极化宽带宽角扫描相控阵。基于电磁镜像原理,通过嵌入人工磁导体,提出了一款具备宽波束辐射能力的+45°极化天线单元,其相对带宽达18.2%,水平方位面的3 dB 波束宽度达114°,展示出宽角扫描潜能。将上述单元组成4×16 均匀面阵并研究相控阵宽角扫描特性。计算结果表明,该面阵能在水平方位面实现±80°宽角扫描,在垂直方位面实现-20°~+30°扫描。     

一种高精度幅相调理机制

该文阐述了一种高精度幅相调理机制(APMM),具有高可靠、高线性幅相特性及快速设计等优点。通过逐级联试,可使任意多通道模组的通道间相位差一致性≤±1°,任意功能单元间幅度一致性≤±1 dB,相位一致性≤±1.5°,任意功能单元的绝对延时精度≤±1.5 ps,多倍频相对带宽的幅度平坦度≤±1 dB。该调理机制可应用于任意电子系统、任意信道化设计、任意功能电路或芯片设计等。通过大量工程应用,并得以证实,该方案切实可靠地改善了目前各类射频系统或模块单元的幅相特性。     

带数字驱动的高集成2～18GHz时延放大多功能MMIC

基于E/D15PHEMT工艺研制了一款2~18GHz用于相控阵雷达的时延放大多功能MMIC芯片。本芯片是一款集成了放大器、单刀双置开关、六位大波长时延器、数字驱动器等功能的多功能芯片,芯片尺寸为5mm×5mm。测试结果表明:发射接收增益皆大于-2dB,P-1在整个频带内达到12dBm。时延最小步进为10ps,最大时延量630ps,时延精度在发射和接收模式下为标称值的±4%,寄生调幅小于2dB。该芯片能够抗基于HBM的250V静电电压。     

Ka波段4位大波长数控时延器

基于0.15μm E/D PHEMT工艺研制了一款28~32GHz用于相控阵雷达的时延器芯片,该芯片是由4位大波长数控时延器及数字驱动器电路组成。为了增强芯片在组件中使用的灵活性,计划分成两块芯片来实现。芯片尺寸分别为1.9mm×2.2mm和2.9mm×2.2mm。实测结果:芯片总插入损耗小于24dB,在28~32GHz带宽内时延步进为33.3ps,最大时延量为500ps,时延精度小于标称值的±3%,寄生调幅小于±0.4dB。该芯片能够抗基于HBM的250V静电电压。     

基于90°电桥芯片的小型化和差器设计

介绍了一种基于90°电桥芯片的和差器的设计原理、封装测试方法以及实测结果。针对小型化设计、测试的难点进行攻关,在低温共烧陶瓷(LTCC)基板表贴电桥芯片,并在基板内部引出走线至基板表面,形成测试端口;利用微组装技术实现小型化高集成设计方案。在此基础上设计封装壳体,实现芯片气密封装,提高工程应用可靠性。根据组件实测结果,驻波比小于1.8,幅度一致性优于±0.8 dB,相位一致性优于10°,质量为35 g。     

一款宽带实时延迟线芯片的设计和实现

为降低电子系统在宽带运用中波束倾斜效应的影响,开展了相关的技术研究。简要介绍了实时延迟线电路的基本概念,对电路设计流程进行了阐述。最终成功开发出一款具有小尺寸和优异微波性能的GaAs微波单片集成数控实时延迟线电路。其性能指标为:工作频率2～8GHz,插入损耗≤23dB,总延时量为637.5ps,驻波比≤1.5∶1。同时指出,要获得高精度的实时延迟线芯片,正确选择控制器件的连接方式和分析延时网络的寄生效应是必要的。     

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-