溶胶-凝胶K_(0.5)Bi_(0.5)TiO_3陶瓷的高温XRD研究

采用溶胶-凝胶法成功制备出K0.5Bi0.5TiO3(KBT)纳米微粉,并利用此微粉烧结出成瓷良好的KBT陶瓷。用XRD法测定了KBT陶瓷粉末室温和高温(600°C)时的点阵常数,确定KBT的高温相为立方结构(点群为m3m)并指标化其衍射线,给出了KBT陶瓷粉末的多晶XRD数据。     

Design of TE01δ Test Probe for Measuring the Microwave Surface Resistance of HTS Thin Film

A new TE01δ test probe with proper transmission factor is fabricated for the measurement of surface resistance of high temperature superconductor (HTS) thin film. Coupling holes instead of coupling loops are used in the probe for its easier machining and relatively low loss. Two 6 mm × 3 mm × 8 mm dielectric waveguides, one side of them is coated by silver, are used for coupling. The measurement result of S21 agrees well with the simulation because the size of the probe can be rigidly controlled by machine. The microwave surface resistance of four YBCO/MgO films are measured at 77 K and 12 GHz and scaled to 10 GHz according to the f 2 rule. The average surface resistance of four HTS thin films is 0.38 mΩ, the standard deviation and relative standard deviation of one single HTS thin film are 0.009 mΩ and 2.4%, respectively.     

改进蚁群算法在空调冷冻水系统中的应用研究

针对空调冷冻水系统存在的时间滞后、多干扰等特点和传统PID控制器控制效果不佳等问题进行了控制策略的优化。将改进蚁群PID控制器应用于冷冻水系统中,并对蚁群算法在寻优时易出现的停滞现象进行改进。最后,通过Matlab软件进行仿真实验,表明了基于改进蚁群算法PID控制的冷冻水系统有效地改善了控制环节的惯性大、时间滞后等问题,提高了系统的准确性与稳定性。     

PIN二极管变温度高频动态建模方法

The PIN diode model for high frequency dynamic transient characteristic simulation is important in conducted EMI analysis. The model should take junction temperature into consideration since equipment usually works at a wide range of temperature. In this paper, a temperature-variable high frequency dynamic model for the PIN diode is built, which is based on the Laplace-transform analytical model at constant temperature. The relationship between model parameters and temperature is expressed as temperature functions by analyzing the physical principle of these parameters. A fast recovery power diode MUR1560 is chosen as the test sample and its dynamic performance is tested under inductive load by a temperature chamber experiment, which is used for model parameter extraction and model verification. Results show that the model proposed in this paper is accurate for reverse recovery simulation with relatively small errors at the temperature range from 25 to 120 ℃.     

Interconnection Technology Based on InSn Solder for Flexible Display Applications

A novel interconnection technology based on a 52InSn solder was developed for flexible display applications. The display industry is currently trying to develop a flexible display, and one of the crucial technologies for the implementation of a flexible display is to reduce the bonding process temperature to less than 150°C. InSn solder interconnection technology is proposed herein to reduce the electrical contact resistance and concurrently achieve a process temperature of less than 150°C. A solder bump maker (SBM) and fluxing underfill were developed for these purposes. SBM is a novel bumping material, and it is a mixture of a resin system and InSn solder powder. A maskless screen printing process was also developed using an SBM to reduce the cost of the bumping process. Fluxing underfill plays the role of a flux and an underfill concurrently to simplify the bonding process compared to a conventional flip‐chip bonding using a capillary underfill material. Using an SBM and fluxing underfill, a 20 μm pitch InSn solder SoP array on a glass substrate was successfully formed using a maskless screen printing process, and two glass substrates were bonded at 130°C.     

FBG位移和温度双参量传感实验研究

采用一种新颖的等强度梁FBG传感结构，将光纤光栅沿梁的轴向粘贴在传感梁上，并确保光栅的一半粘贴在梁上，另一半则沿梁的轴向呈自由状态。通过两部分光栅对梁自由端位移和环境温度的不同响应，实现温度和位移的同时测量，测量误差不大于4％。通过多次实验验证，所得实验结果与理论分析相符合。     

基于翼表温度测量的光纤Bragg光栅传感器研究

根据可变体机翼翼表温度检测范围-60～+80℃的要求,提出了一种基于铝板片封装的光纤Bragg光栅(FBG)温度增敏传感装置.该装置采用耐高温环氧树脂胶将FBG粘贴在铝板片U槽中,并预热60℃、保持30 min以保证FBG温度传感增敏装置线性和重复性.研究及试验结果表明,在翼表工作环境温度范围内,该模型理论与实测温度灵敏度分别为28.16 pm/℃和29.03 pm/℃.与裸光栅相比,其增敏倍数分别为2.540倍和2.636倍,增敏倍数误差为3.78％,反射波长与温度的线性度达到0.999 3.因此,在翼体工作环境温度范围内尤其低温环境-60～0℃间,该温度增敏传感装置能满足检测所需精度.     

基于TSIC506的高精度温度检测系统的设计

以ATmega16单片机为控制核心,利用数字化温度传感器TSIC506实现高精度温度检测系统。论述了该系统的硬件组成和软件设计,给出了系统总体结构及相应的ATmega16单片机温度测量程序。实际应用表明,该温度检测系统具有结构简单、成本低、稳定实用等特点,可根据不同需要应用于多种工农业温度检测领域。     

基于Labview的光纤光栅温度传感器实验研究

提出了一种基于Labview语言的实时数据采集及处理系统设计方案,介绍了光纤光栅温度传感波长解调原理,应用Labview语言编写了程序,实现对数据的处理和显示,试验结果表明:该系统能够有效利用计算机实现信号的处理,满足FBG传感器实时数据采集和处理的要求,获得了0.3℃温度测量精度和0.1 ℃分辨率.     

一种温度不敏感的高线性功率放大器

设计了一种温度不灵敏的高线性度的射频功率放大器芯片,采用新颖的带温度反馈环路的有源片上自适应偏置电路,该电路降低了温度引起的放大器集电极直流电流分量的变化量,补偿了由温度变化而引起的性能偏差,进而有效提高了放大器的线性度。基于这个温度不灵敏的偏置结构采用InGaP/GaAs HBT工艺设计了一个工作在2110~2170 MHz频段的功率放大器。测试结果表明,该功放在工作频段内的增益大于等于35.3 dB;在中心频率2140 MHz处,1 dB功率压缩点大于33 dBm,功率附加效率在输出功率24.5 dBm时为18%;使用LTE_FDD调制信号,获得邻信道功率比为-47 dBc。在环境温度为-40℃、+25℃和+80℃条件下,功放的增益平坦度较好,增益变化量小于1.5 dB,输出级集电极电流基本不变,有效降低了功放对温度的敏感性。