CCD相机的亮度色度校准装置研制

CCD相机的亮度和色度测试仪器凭借其一系列的测量优势已广泛应用于平板显示器的测量领域。本文在综合国内外相关计量标准技术优势的基础上,根据平板显示行业所特有的溯源需求进行校准装置的研制,基于积分球匀光和光谱测色原理,研制出CCD相机的亮度色度校准装置,并对校准装置的计量性能和特性进行研究以及对装置的测量结果进行验证。结果表明,该校准装置满足作为计量标准的技术要求,可用于CCD相机亮度和色度参数的校准。     

A Precision Dc Potentiometer Microwave Insertion Loss Test Set

A simple, accurate microwave test set has been devised for measuring coaxial or waveguide insertion loss. The instrument is designed primarily for highest precision with low attenuations. It is composed almost entirely of commercially available equipment and components, is portable, and can be operated in the laboratory or in the field from ac mains or batteries. The precision of the measurements depends on the connector type and value of the component measured. The precision is better than 0.0001 dB when measuring low insertion losses, discounting the error due to the connectors. Equipment nonlinearity reduces the precision in proportion to the measured attenuation in dB. The frequency range covered is 10 MHz to 40 GHz, which can be extended to 90 GHz with slight perfornance degradation.     

Millimeter-wave antireflection coating for cryogenic silicon lenses

We have developed and tested an antireflection (AR) coating method for silicon lenses used at cryogenic temperatures and millimeter wavelengths. Our particular application is a measurement of the cosmic microwave background. The coating consists of machined pieces of Cirlex glued to the silicon. The measured reflection from an AR-coated flat piece is less than 1.5% at the design wavelength. The coating has been applied to flats and lenses and has survived multiple thermal cycles from 300 to 4 K. We present the manufacturing method, the material properties, the tests performed, and estimates of the loss that can be achieved in practical lenses.     

核燃料组件运输容器应用现状概述

目的 充分了解国内外核燃料组件运输容器的主要应用现状,通过对照国外发展经验,为更好地实现国内运输容器自主化发展提出意见建议。方法 调研和分析国际上主要核大国代表性核燃料组件运输容器的技术现状,以及国内容器的研发、应用状况,梳理了自主化发展中仍需改进的方向。结果 国际上主要核大国利用核能技术较早,均已针对本国的反应堆技术开发了成熟的运输容器产品,相比之下,目前国内在引进和吸收国外先进技术的基础上,也已逐渐实现了部分核燃料组件运输容器的国产化,并针对高温气冷堆开发了新型运输容器。结论 建议注重核燃料组件运输容器的系列化发展,增加攻克关键技术的投入,继续推进容器设计评价软件开发与试验验证平台的建设。     

Analytical thermal stress model for a typical flip-chip (FC) package design

A simple analytical thermal stress model is suggested for a typical flip-chip (FC) lidded package design. The model is based on the concept of the interfacial compliance. The addressed design consists of a silicon FC bonded to an organic substrate and covered by a lid. The lid is configured in such a way that its mid-portion is bonded to the back side of the chip using a thermal interface material (a heat sink is intended to be subsequently mounted on the outer surface of the lid) and the lid’s peripheral portions are adhesively bonded to the same substrate using compliant attachments around the lid’s perimeter. A copper lid and a (hypothetical) organic lid are considered to develop a general feeling of the possible stress relief that could be expected if an organic lid is employed. The in-plane compliances of all the attachments, including the effective compliance of the encapsulated solder joint interconnections, are taken into account. A numerical example shows how the model could be used in practical computations. It shows also that the application of an organic lid, although is less attractive from the standpoint of the thermal management of the design, might result in appreciably lower thermal stresses. This is true for both the normal stresses in the chip’s cross-sections and the maximum interfacial shearing stresses at the chip’s ends. The developed model can be employed in the analysis of a FC package design of the type in question. Future work should include FEA verifications, and the suggested analytical stress model can be of help when developing a FEA preprocessing simulation model.     

基于虚拟仪器微压力真空包装气密性研究

目的利用虚拟仪器对真空包装气密性进行检测,判断食品包装是否存在泄漏。方法构建的真空包装检测系统由压力传感器测得信号,经过调理电路传至数据采集卡,并最终输送到计算机,通过Labview软件构建的虚拟仪器将变化的压力信号通过图形显示出来。结果通过实验,利用虚拟仪器对真空包装气密性密封进行检测,判断出了食品包装是否存在泄漏。加压结束后,容器内压力随时间增加会慢慢减小,则表明该包装有泄漏;加压结束后,容器内压力随时间基本保持不变,则表明包装的密封性良好。结论用虚拟仪器对真空包装气密性密封进行检测是以后重要的发展方向。     

Instrument to measure the bidirectional reflectance distribution function of surfaces

A new instrument to measure the in situ bidirectional reflectance distribution function (BRDF) of surfaces is described. This instrument measures the BRDF for eight illumination angles from 0 to 65 deg, three colors (475, 570, and 658 nm), and at over 100 selected viewing angles. The viewing zenith angles range from 5 to 65 deg, and the azimuth angles, relative to the illumination direction, range from 0 to ?180 deg. Many tests of the system have been run and show that for flat surfaces the BRDF of a sample surface can be measured with a precision of 1-5% and an accuracy of 10% of the measured reflectance. The BRDF for a dry and wet sand sample is presented as a demonstration of the instrument.     

Noncontacting low-cost instrument for film thickness measurement

A low-cost, noncontacting, nondestructive technique is presented for measuring the thickness of thin liquid or solid films and coatings in real time by utilizing the resonance properties of microstrip structures. A new measurement system in which all the microwave components are internal to the instrument, thereby eliminating the need for microwave test equipment, is described. Only a low-voltage DC source, such as a battery, is required to power the unit; the output is also a DC voltage or current. Using a linear model, sample coefficients of determination, r², greater than 0.98 have been obtained for film thickness measurements of water, enamel paint, and silicon rubber up to 0.8-1.5- and 2-mm thick, respectively. Copper sheet metal up to 0.9-mm thick has been measured with an r² greater than 0.99. The measurement range can be extended or improved even further if nonlinear circuit behavior is accounted for     

液晶电视跌落测试动态脆值分析

论述了液晶电视全瓦楞缓冲包装结构设计方案,并对跌落测试数据进行了分析,论证了缓冲衬垫在装配过紧或较松的情况下,包装件在跌落测试中会产生不同的冲击响应谱曲线。据此提出了动态脆值概念,利用反推法寻求了最适合的动态脆值,优化了产品缓冲包装设计。     

Adaptive Microwave Holography

Microwave holography differs from optical holography in three distinct ways. First, in microwave holography the reference field may be eliminated and replaced by correct phasing of the local oscillator within the microwave receiver. Second, the reference wave need not coexist in time with the signal or object field. Third, it is not necessary that the object field be measured simultaneously across the array. Aside from these fundamental differences, which give the microwave holographer additional freedom in system design, another practical difference should be noted. Because of the long wavelength used in microwave holography, the aperture must be huge to obtain images with fine resolving power. Such apertures are often mechanically unstable. By introducing adaptivity or self-cohering into the creation and measurement of the reference field, it is possible to ‘straighten out’ a distorted microwave aperture. An instrument which performs these operations is called a radio camera. A twodimensional radar map of a few blocks of a small town in Pennsylvania illustrates the process.     

A Mid-IR Pyrometer Calibrated with High-Temperature Fixed Points for Improved Scale Realization to 2,500°C

Glass surface temperature can be measured using a radiation thermometer operating at a mid-IR wavelength, typically the 3–5 μm band, where the glass is opaque. For optical fiber preforms, the temperature measurement requirement may exceed 2,200°C. Scale realization at national measurement institutes at these temperatures is usually carried out at short wavelengths, typically less than 1 μm. The mismatch in wavelength can lead to significant uncertainties when calibrating a radiation thermometer working at 3–5 μm. To overcome this, a narrow band 3.95 μm radiation thermometer has been built that is designed to be used from 1,000 to 2,500°C. It is calibrated by measurement of high-temperature metal–carbon eutectic fixed-points. The instrument is based on silicon lenses, with a liquid nitrogen (LN₂)-cooled InSb detector, and narrow-band interference filter. An anti-reflection coated objective lens/aperture stop focuses onto a field stop giving a 1 mm target, then a collimating lens, and glare stop. All parts visible to the detector, other than the target area, are either at LN₂ temperature or are part of a temperature-stabilized housing. A relay-operated shutter that blocks the field stop is used to subtract the background. The size-of-source effect of the instrument has been measured. Gold-point measurements have been made to assess the stability. The device has been calibrated using high-temperature fixed points. A three-parameter fit has been applied and the resultant scale compared to an ITS-90 realization.     

介质谐振器介电参数频响特性及频率温度系数的测量

本文讨论了微波介质谐振器介电参数频响特性和频率温度系数的测试方法、测试装置和测试系统。用Q值较高的TE0mn模作为测试介电参数的工作模式 ,取不同下标m和n的TE0mn模式进行测量 ,以获得介电参数的频响特性。为克服常规测试方法因耦合方式不当激励起杂模干扰高次TE0mn 模测试的问题 ,提出了新的耦合方式 ,研制了测试装置。同时 ,还研制了结构巧妙的频率温度系数测试装置。实测表明 ,该测试方法、测试装置和测试系统能对介电参数频响特性及频率温度系数进行快速、准确、可靠、无损伤和批量的自动测试。     

Measurement and control of current/voltage waveforms of microwavetransistors using a harmonic load-pull system for the optimum design ofhigh efficiency power amplifiers

One of the most important requirements that RF and microwave power amplifiers designed for radiocommunication systems must meet is an optimum power added efficiency (PAE) or an optimal combination of PAE and linearity. A harmonic active load-pull system which allows the control of the first three harmonic frequencies of the signal coming out of the transistor under test is a very useful tool to aid in designing optimized power amplifiers. In this paper, we present an active load-pull system coupled to a vectorial “nonlinear network” analyzer. For the first time, optimized current/voltage waveforms for maximum PAE of microwave field effect transistors (FET's) have been measured. They confirm the theory on high efficiency microwave power amplifiers. The proposed load-pull setup is based on the use of three separated active loops to synthesize load impedances at harmonics. The measurement of absolute complex power waves is performed with a broadband data acquisition unit. A specific phase calibration of the set-up allows the determination of the phase relationships between harmonic components. Therefore, voltage and current waveforms can be extracted. The measurement results of a 600 gate periphery GaAs FET (Thomson Foundry) exhibiting a PAE of 84% at 1.8 GHz are given. Such results were obtained by optimizing the load impedances at the first three harmonic components of the signal coming out of the transistor. Optimum conditions correspond to a class F operation mode of the FET (i.e., square wave output voltage and pulse shaped output current). A comparison between measured and simulated current/voltage waveforms is also presented     

行波管夹持杆微波性能的自动测量

本文讨论了行波管夹持杆微波性能的测试技术。采用模式识别技术，实现了在不同频段用一测试腔对夹持杆介电参数的测量。     

聚乙烯缓冲材料多自由度跌落包装系统优化设计

在测试基础上,依据粘弹性力学理论,建立发泡聚乙烯缓冲材料动态非线性本构模型,并成功识别了模型参数;应用此模型在一定高度跌落冲击下,建立了多自由度包装系统动力学方程;依据物品响应加速度小于许用值及材料用量最小化两个原则,进行多自由度系统缓冲包装优化设计并获得最优解;基于最优解结构尺寸,测试了发泡聚乙烯缓冲系统的加速度响应值,数值算例及试验的结果表明理论值与试验值的平均相对误差都在0.8%以内。利用此设计方法可有效地避免欠包装和过度包装,克服了最大加速度-静应力曲线不能设计多自由度缓冲包装设计的弊端     

Lateral emitter as a base element of integrated emission electronics

A field emitter is the principal element of emission electronics determining the performance of devices. We propose a lateral emitter based on carbon nanotubes for use in integrated emission electronics. The dependences of the emission current on the pulling and control fields have been studied. It is shown that the proposed lateral emitter can be used in all microelectronic analogues of vacuum tubes, from microwave devices to flat displays, the device technology being substantially integrated.     

On the flicker noise of ferrite circulators for ultra-stable oscillators

The flicker noise of the ferrite circulator is a critical element in ultra-stable microwave oscillators, in which the signal reflected from the input of the reference cavity is exploited to stabilize the frequency. This paper explains why the circulator noise must be measured in isolation mode, proposes a measurement scheme, and provides experimental results. The observed flicker spans from -162 to -170 dB[rad2]/Hz at 1 Hz off the 9.2 GHz carrier, and at +19 dBm of input power. In the same conditions, the instrument limit is below -180 dB[rad2]/Hz. Experiments also give information on the mechanical stability of the microwave assembly, which is in the range of 10(-11) m. The measurement method can be used as the phase detector of a corrected oscillator; and, in the field of solid-state physics, it can be used for the measurement of random fluctuations in magnetic materials.     

Sprint start instrumentation

A prototype instrument has been developed to measure the forces generated on the starting blocks and the speed of a sprinter at the start of a sprint event. The starting block forces can be resolved into horizontal and vertical components for each foot, or the various combinations of these four forces can be calculated and displayed along with the resultant angle. The speed of the sprinter is measured by means of a Doppler microwave technique (radar gun). Both static and dynamic tests have been used to calibrate the force transducers and to verify their functional bandwidth. The speed measurement technique has been validated by four independent procedures: measurement of a constant velocity object; measurement of an object undergoing constant acceleration; determination of distance travelled by an athlete; and comparison with high-speed cinematography. Both the force and speed profiles can be displayed immediately on the screen of a microcomputer for feedback to the coach and athlete during training sessions     

Horn antenna analysis as applied to the evaluation of thegain-transfer method

An important condition that has to be satisfied when implementing the gain-transfer method is that the fields in the test zone of the measurement facility should be as close to the plane wave as possible. In this paper, the effect of amplitude and phase deviation from a perfect plane wave, on gain measurements for microwave aperture antennas, conducted via the gain-transfer method, is determined and quantified. The pyramidal horn antenna is used as a basis for all calculations as it is the universal standard for microwave antenna gain measurements. Coupling, between the antenna being illuminated and the test zone fields, is evaluated by means of the reciprocity theorem. Test zone field variations are simulated and the effect thereof, on the predicted measured gain, is illustrated     

A Millimeter Wave Complex Reflection Coeficient Scanner

A broadband microwave measurement system has been designed to make complex reflection coefficient measurements on a swept basis at millineter wave frequencies. This instrument covers a frequency range of 50-75 GHz in WR-15 rectangular waveguide. Two appliques are being added in WR-22 and WR-10 waveguide to extend the frequency range of the system to 33-110 GHz. Measurements can be made while sweeping over bands as wide as 10 GHz. An interesting feature of the complex reflection coefficient scanner is that residuals, or baseline, of the system are automatically subtracted. The resultant output display is a real-time polar plot of the actual reflection coefficient of the network under test. Residuals of 0.03 for reflection coefficients around unity, and 0.013 for reflection coefficients around zero can be measured with a resolution of 0.01 while sweeping over a 5 GHz band. A maximum reflection coefficient range of 46 dB has been achieved using straightforward video detection techniques. For measurements of networks with very low reflection coefficients (0.01 and lower) a time averaging feature is available to reduce the effects of random noise. The complex reflection coefficient of the unknown can be displayed on an oscilioscope and photographed, or read out on an X-Y plotter.