高频声表面波陷波器

报道了817MHz声表面波陷波器的设计及结果。该陷波器采用T型带陷滤波器等效电路结构,用两个SAW单端对谐振器加简单调谐元件构成,器件尺寸为3.8mm×3.8mm,陷波深度为15dB,-3dB陷波宽度为600kHz,通带宽度大于700MHz,通带损耗为-0.735dB,通带波纹0.5dB。最后讨论了影响高频陷波器指标恶化的原因。     

S波段网格型FBAR滤波器的研制

介绍了一种单端口,端口阻抗为50 Ω的S波段宽带薄膜体声波谐振器(FBAR)滤波器,该滤波器采用网格型结构的FBAR滤波器芯片级联巴伦芯片实现.对宽带FBAR滤波器芯片的设计过程、工艺实现过程进行了说明.采用0.35 μm GaAs工艺实现了3～8 GHz频率范围的巴伦芯片,在FBAR滤波器芯片的中心频率处,幅度不平衡度为0.53 dB,相位不平衡度为0.55°.制备的FBAR滤波器通带频率范围为3 100～3 400 MHz,1 dB带宽约为369 MHz,在2 660 MHz和3 840 MHz处带外抑制分别为45.6 dBc和41.3 dBc,尺寸仅为12 mm×7 mm×2.9 mm.将实测结果与仿真结果进行了对比,两者一致性很好.     

宽带FBAR滤波器的研制

采用阶梯型结构的薄膜体声波谐振器(FBAR)滤波器芯片和外匹配电路实现了一种输入输出端口阻抗均为50 Ω的宽带FBAR滤波器.FBAR滤波器芯片采用自主的FBAR滤波器工艺实现,外匹配电路采用0.35 μm GaAs工艺实现,并在该芯片上植球,采用倒装工艺将FBAR滤波器芯片与外匹配电路芯片进行异构集成.然后采用微组装工艺将异构集成芯片装配在标准陶瓷外壳中,外壳通过平行封焊工艺实现气密封装,体积仅为3.8 mm×3.8 mm×1.8 mm.测试结果显示,该滤波器通带频率范围为3 300～3 600 MHz,1 dB带宽约为300 MHz,相对带宽为8.7％,插入损耗为1.41 dB,在3 250 MHz和3 650 MHz处带外抑制分别为16.5 dBc和48.2 dBc.将实测结果与仿真结果进行了对比,两者基本吻合.     

一种高抑制电调滤波器的设计与实现

针对超外差接收机中前端预选宽频段、低损耗与高带外抑制度的需求,文中在电感耦合方式的LC电调滤波器基础上,增加了寄生通带抑制滤波器,设计了一款基于20~800 MHz调谐范围的电调滤波器。通过实际测试得到在调谐范围内,滤波器插入损耗<1.5dB,1 dB相对带宽约20%~30%,输入输出端口驻波<1.5,二倍频处抑制度>40 dBc,寄生通带抑制滤波器能将二次谐波和三次谐波寄生通带的抑制度分别提高40 dBc和30 dBc以上,从而利于滤波器在预选部分实现中频、镜频和本振反向等抑制作用。     

一款2.4GHzWiFi频段FBAR带通滤波器设计

该文设计了一款2.4 GHz WiFi频段(2 401~2 483 MHz)薄膜体声波谐振器(FBAR)滤波器。采用一维Mason电路模型,在ADS中搭建了阶梯形滤波器电路;在HFSS中建立了封装结构和测试电路有限元电磁模型,并在ADS中完成了联合仿真设计。通过微机电系统(MEMS)工艺制备与测试,滤波器在2 401~2 483 MHz频段的插入损耗≤2.2 dB。在2 520~2 900 MHz处,带外抑制≥40 dB,滤波器体积仅1.1 mm×0.9 mm×0.65 mm。     

基于LTCC技术的手机天线开关滤波器

采用LTCC工艺进行手机天线开关滤波器的设计,用于手机天线开关发射端GSM850/900MHz、GSM1800/1 900MHz。整个LTCC滤波器体积为2.5mm×3.2mm×0.75mm,其中包含两个低通滤波器,用于二次谐波和三次谐波的抑制。GSM850/900通带插损小于0.75dB,带内二次谐波抑制度大于23dBc,三次谐波抑制度大于40dBc;GSM1 800/1 900通带插损小于0.7dB,带内二次谐波抑制度大于26dBc,三次谐波抑制度大于28dBc。     

一种应用于多频接收机的宽带频率综合器

采用0.18µm 1P6M CMOS工艺实现了一种应用于多频接收机的整数分频频率综合器。该频率综合器为接收机提供频率分别为2.57GHz, 2.52GHz, 2.4GHz 和 2.25GHz的本振信号。为了覆盖要求的频点,其宽带压控振荡器同时采用了可变电容阵列和可变电感阵列。经测试,压控振荡器的频率调谐范围为1.76GHz~2.59GHz。对于频率为2.57GHz, 2.52GHz, 2.4GHz 和 2.25GHz的载波,在1MHz频偏处,相位噪声分别为-122.13dBc/Hz、-122.19dBc/Hz、-121.8dBc/Hz和-121.05dBc/Hz。其带内相位噪声分别为-80.09dBc/Hz、-80.29dBc/Hz、-83.05dBc/Hz 和-86.38dBc/Hz。包括驱动电路在内的芯片功耗约为70mW。芯片面积为1.5mm×1mm。     

层叠式LTCC低通滤波器设计

给出带有衰减极点的层叠式LTCC低通滤波器的结构模型。滤波器外形尺寸为2.0mm×1.2mm×0.9mm,采用εr=7.8、tanδ=0.0047微波陶瓷介质材料,设计出的截止频率?c=300MHz的低通滤波器,通带最大插入损耗为0.8dB,通过引入一个衰减极点,提高阻带的衰减性能,同时获得陡峭的过渡带。     

一种新型超宽带双陷波平面单极子贴片天线设计

设计一种新型双陷波超宽带单极子贴片天线,辐射贴片为酒杯型天线结构,采用对底部边缘开槽曲流的办法,实现了良好超宽带天线性能。同时对辐射贴片加载了U形和C形缝隙,分别在3.5 GHz和5.5 GHz处产生陷波。利用HFSS软件对所设计天线进行仿真验证,仿真结果与实测结果表明,该天线在超宽带范围内能有效抑制双陷波能力,并且在通带范围有良好辐射和稳定增益特性。其天线尺寸为33 mm×26 mm×0.74 mm,便于集成在电路系统中。     

低噪声整数频率合成芯片的设计

设计了一个锁相环频率合成芯片。该芯片集晶体振荡电路、鉴频鉴相器、电荷泵、分频器、低通环路滤波器和压控振荡器(VCO)等电路于一体。详细分析了频率综合器中的各个关键模块,利用MATLAB软件优化环路参数,简化了电荷泵、VCO和片内环路参数的相关设计。最后,给出了芯片照片和流片测试结果,验证了设计方法和电路设计的正确性。该芯片在0.35μm CMOS工艺下进行了流片,测试结果表明,电源电压3 V,电流25 mA,芯片面积为5.4 mm2(3 000μm×1 800μm)。输出频率0.8~1.2 GHz,步进50 MHz,单边带相位噪声优于-106 dBc/Hz@1 kHz,-106 dBc/Hz@10 kHz,-115 dBc/Hz@100 kHz,-124 dBc/Hz@1MHz,-140 dBc/Hz@10 MHz。     

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-