0.35μm CMOS 8.5GHz 1∶8分频器的设计

实现了一个基于触发器结构用0.35μm CMOS工艺实现的1∶8分频器.它由3级1∶2 分频器单元组成,其中第一级为动态分频器,决定了整个芯片的性能,第二、三级为静态分频器,在低频下能稳定工作.分频器采用源极耦合逻辑电路,并在传统的电路结构上进行改进,提高了电路的性能.测试的结果表明,芯片工作速率超过8.5GHz,工作带宽大于2GHz.电路在3.3V电源电压下工作,每个1∶2分频器单元的功耗约为11mW,面积为35μm×50μm.该芯片可应用于高速射频或光电收发机系统中.     

8~25 GHz 1∶8高速分频器的设计

采用IBM 0.13 μm CMOS工艺,在锁相环系统电源电压2.5 V的条件下,以三级分频器级联的方式实现了一款8~25 GHz 1∶8高速分频器电路。为了获得更高的工作速度和灵敏度,设计中对传统的伪差分结构锁存器进行了拓扑和版图优化,基本的二分频单元由锁存器和输出缓冲级电路构成,以保证版图布线后信号传输的衰减最低。后仿真结果表明:在电源电压2.5 V时,分频器的核心电路(第一级)功耗为21.75 mW,对应的版图尺寸为70 μm×35 μm;在输入信号峰峰值900 mV的条件下,分频范围达到8~25 GHz,并通过了所有工艺角和温度仿真。     

一种可编程的2.4GHz CMOS多模分频器

采用0.35μm CMOS工艺设计并实现了一种多模分频器.该多模分频器由一个除4或5的预分频器和一个除128～255多模分频器在同一芯片上连接而成;在电路设计中,分析了预分频器功耗和速度之间的折中关系,根据每级单元电路的输入频率不同对128～255多模分频器采用了功耗优化技术;对整个芯片的输入输出PAD进行了ESD保护设计;该分频器在单端信号输入情况下可以工作到2.4GHz,在差分信号输入下可以工作到2.6GHz以上;在3.3V电源电压下,双模预分频器的工作电流为11mA,多模分频器的工作电流为17mA;不包括PAD的芯片核心区域面积为0.65mm×0.3mm.该可编程多模分频器可以用于2.4GHz ISM频段锁相环式频率综合器.     

一种可编程的2.4GHz CMOS多模分频器

采用0.35μm CMOS工艺设计并实现了一种多模分频器.该多模分频器由一个除4或5的预分频器和一个除128～255多模分频器在同一芯片上连接而成;在电路设计中,分析了预分频器功耗和速度之间的折中关系,根据每级单元电路的输入频率不同对128～255多模分频器采用了功耗优化技术;对整个芯片的输入输出PAD进行了ESD保护设计;该分频器在单端信号输入情况下可以工作到2.4GHz,在差分信号输入下可以工作到2.6GHz以上;在3.3V电源电压下,双模预分频器的工作电流为11mA,多模分频器的工作电流为17mA;不包括PAD的芯片核心区域面积为0.65mm×0.3mm.该可编程多模分频器可以用于2.4GHz ISM频段锁相环式频率综合器.     

基于0.13 μm CMOS工艺的低电压高速1:2分频器设计

在光纤传输系统中,分频器是工作在最高频率的电路之一,起着至关重要的作用,本文就采用了由锁存器构成的数字1:2分频器.采用UMC 0.13μm CMOS工艺,设计了电源电压为1V,工作频率范围为5～20GHz的1:2分频器电路.该电路由基本分频器单元以及输入输出缓冲组成.基本分频器单元采用单端动态负载锁存器.整体电路功耗...     

一种新的相位开关实现技术及其在射频双模预分频器中的应用

提出了一种新的相位开关实现技术 .基于这种技术设计了一个 2 / 3分频器单元 ,该单元结构简单 ,工作频率高 ,功耗低 .为了验证该技术 ,采用 0 .2 5μm CMOS数字工艺实现了一个 12 8/ 12 9双模预分频器 .对该芯片的测试结果表明其能正确工作于 GHz频率范围 .当工作频率为 2 .3GHz时 ,它消耗的电流仅为 13.5 m A(2 .5 V电源电压 ) ,芯片面积为 0 .4 7mm× 0 .4 7m m.     

10～37 GHz CMOS四分频器的设计

给出基于0.13μm CMOS工艺、采用单时钟动态负载锁存器设计的四分频器.该四分频器由两级二分频器级联而成,级间采用缓冲电路实现隔离和电平匹配.后仿真结果表明其最高工作频率达37 GHz,分频范围为27 GHz.当电源电压为1.2 V、工作频率为37 GHz时,其功耗小于30 mW,芯片面积为0.33×0.28 mm2.     

低功耗0.35μm 3.125Gbit/s CMOS4∶1复接器

采用CSM0.35μm CMOS工艺,设计了3.125Gbit/s4∶1复接器.系统采用树型结构,由两个并行的低速2∶1复接单元和一个高速2:1复接单元级联而成.低速单元采用带有电平恢复的传输管逻辑实现,高速单元采用动态传输门逻辑实现.具体电路由锁存器、选择器、分频器以及输入输出缓冲组成.复接器芯片面积为0.675mm×0.6mm.3.3V电源电压下,芯片整体功耗小于130mW,核心功耗是25mW.最高工作速率可达4Gbit/s.     

10～37GHzCMoS四分频器的设计

给出基于0．13μmCMOS工艺、采用单时钟动态负载锁存器设计的四分频器。该四分频器由两级二分频器级联而成。级间采用缓冲电路实现隔离和电平匹配。后仿真结果表明其最高工作频率达37GHz，分频范围为27GHz。当电源电压为1．2V、工作频率为37GHz时，其功耗小于30mW，芯片面积为0．33-0．28mm2。     

一种基于新的优化结构和动态电路技术CMOS双模预分频器

提出了一种应用新的电路结构和动态电路技术的双模预分频器,它已用0.25μm CMOS数字工艺实现.新的优化结构减少了电路的传输延迟,提高了电路速度.基于这种优化结构和动态电路技术,提出了改进的D型触发器.为了验证其功能,制作了一个试验型芯片.经测试,该分频器在可以工作于GHz频率范围;在电源电压为2.5V,输入频率为2.5GHz时,其功耗仅为35mW(包括三个功耗很大的输出缓冲器的功耗).由于其具有良好的性能,该分频器可应用于许多射频系统中.     

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.     

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.     

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.     

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.     

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.     

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     

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正Communications—VLSI Researches and industries of telecommunications have been growing rapidly in the last 20 years and will keep their high growing pace in the next decade.The involved researches and developments cover mobile communications,highway and last-mile broadband communication,domain specific communications,and emerging D2D M2M communications.Radio communication steps into its