声表面波VCO的研制

介绍了１５５．５２ＭＨｚ、６２２．０８ＭＨｚ声表面波（ＳＡＷ）、１２４４．１６ＭＨｚ浅体波（ＳＴＷ）压控振荡器（ＶＣＯ）的原理、设计和性能。采用低插损、高Ｑ值的ＳＡＷ延迟线和ＳＴＷ谐振器，高性能微波放大器，变容二极管电移相器，使振荡器具有非常低的相位噪声（＜－１４０ｄＢｃ／Ｈｚａｔ１００ｋＨｚ）、高输出功率（＞９ｄＢｍ）、低温度－频率漂移（＜±３５ｐｐｍ，温度范围：－５～６０℃）、大频率调谐范围（＞４００ｐｐｍ）。     

声表面波脉的冲编码调制振荡器

论述了一种直接式声表面波脉冲编码调制振荡器的工作原理及设计方法。实际制作了工作频率为３９４ＭＨｚ、调制频偏大于２００ｋＨｚ、调制信号码速率大于４００ｋｂｉｔ／ｓ输出率大于５０ｍＷ、温度稳定性优于±５０×１０＾－６（－２０－＋６０℃）的性能优良的声表面波脉冲编码调振振荡器。     

宽频偏声表面波压控振荡器研究

介绍宽频偏声表面波压控振荡器的实验研究。这种声表面波压控振荡器的工作频率为１８．３～１９．２ＭＨｚ，分四个频段进行数字信号控制，每一频段的压控频偏均大于３００ｋＨｚ，单边带相位噪声优于－１００ｄＢｃ／Ｈｚ／１ｋＨｚ，平均压控灵敏度大于５０ｋＨｚ／Ｖ。     

一种新型毫米波频率调制器研究

本文给出一种新型毫米波频率调制电路，是将腔稳Ｇｕｎｎ振荡器与变容管调制电路通过反馈调节电路耦合起来形成的，在确需调制频偏的情况下，通过调整环路反馈系数可减少小变容客调制电路对Ｇｕｎｎ振荡器中心频率稳定度的影响，Ｇｕｎｎ振荡器中加一高Ｑ稳频腔，从而可以获得较高的频率稳定度。调制器调制灵敏度为３．５ＭＨｚ／Ｖ，调频线性度估于２％，中心频率稳定度６．５ｐｐｍ／℃（－２０－５０℃），输出功率大于１７ｄＢｍ     

声表面波脉冲编码调制振荡器

论述了一种直接式声表面波脉冲编码调制振荡器的工作原理及设计方法。实际制作了工作频率为３９４ＭＨｚ、调制频偏大于２００ｋＨｚ、调制信号码速率大于４００ｋｂｉｔ／ｓ、输出功率大于５０ｍＷ、温度稳定性优于±５０×１０－６（－２０°Ｃ～＋６０°Ｃ）的性能优良的声表面波脉冲编码调制振荡器     

一种声表面波声纳浮标

过去有人阐明了利用声表面波(SAW)器件制作压力敏感器的可能性.SAW压力敏感器可以在振荡器的反馈电路上设置一个延迟线或谐振器构成.当一个负载作为弯曲力矩加到压电基片上时,则产生如图1所示的现象,它改变了表面波速度,进而改变了振荡器的中心频率.因此,当加上一个变化的负载时,则在振荡器的输出端产生一个调频信号,该调频信号含有压力信号的信息.同时,SAW压力换能器     

高频调制射频激励紧凑型波导CO_2激光器的实验研究

采用增益调制技术．获得最高达２００ｋＨｚ高重复频率的激光调制方脉冲输出，当重复频率小于２０ｋＨｚ时，获得尖峰前沿方脉冲输出，其尖峰峰值功率大于方脉冲功率的３倍。     

一种新型声表面波振荡器系统的设计研究

针对振荡器中声表面波器件存在的体声波干扰、电极反射及旁瓣过大问题,提出了一种新型声表面波振荡器系统的设计方案。该方案将多条耦合器用于分离体声波,分裂电极用于减弱电极反射问题,并采用了输入、输出换能器双加权的措施来降低旁瓣信号。通过对一个中心频率为50.8MHz声表面波振荡器的实现和测试,得到该新型声表面波振荡器系统的振荡频率为50.613 MHz,与系统的设计值误差仅为3.6‰,并且具有良好的周期性和稳定性。     

一种实用的压控振荡器

介绍一种电压控制振荡器的电路特点及工作原理。实验结果表明：该振荡器性能稳定，频率可控范围宽，连续均匀压控线性区为１１００ｋＨｚ，压控灵敏度为２．５ＭＨｚ／Ｖ。文章最后对研制中的有关问题进行了讨论。     

高频声表面波压控（调频）振荡器的研制

本文讨论了声表面波压控(调频)振荡器的原理及设计方法,并实际制作了振荡器,中心频率为657MHz,频偏约为1.5×10~(-3),平均压控灵敏度为98kHz/V,线性度±2%,温度稳定度为±3.7×10~(-5)(-20—+60℃)。     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

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.