基于LTCC 的北斗接收机开关电路小型化设计

基于LTCC（Low Temperature Co-fired Ceramic）技术将多工器、扼流器、微波传输线等内置于LTCC 基板内, 开关电路和隔直电容等表贴器件通过台阶腔形式内置或放置顶层,从而实现北斗单兵接收机开关电路小型化设计。该 电路具有插损低、抑制高、体积小（实际尺寸为10mm×9mm×4mm）等特点。     

In-situ characterization of interface delamination by a new miniature mixed mode bending setup

A new miniature mixed mode bending (MMMB) setup for in-situ characterization of interface delamination in miniature multi-layer structures was designed and realized. This setup consists of a novel test configuration to accomplish the full range of mode mixities and was specially designed with sufficiently small dimensions to fit in the chamber of a scanning electron microscope (SEM) or under an optical microscope for detailed real-time fracture analysis during delamination. Special care was taken to minimize the effects of friction, the influence of gravity, and non-linearities due to the geometry of the setup. The performance of the setup was assessed using specially-designed test samples supported by finite element analyses. Delamination experiments conducted on homogeneous bilayer samples in mode I and mixed mode loading were visualized with a scanning electron microscope and showed the formation of small micro cracks ahead of the crack tip followed by crack bridging and a full crack, thereby demonstrating the advantages of in-situ testing to reveal the microscopic delamination mechanism.     

小型UPS电源的嵌入式系统设计与实现

针对直流不间断电源纹波小、输出稳定的特点,提出了一种小型智能化UPS系统的嵌入式设计方案。系统结合高效AC-DC模块、LTC1512稳压充电模块、LTC3780高性能降压-升压型放电模块和LTC4256热插拔保护模块,以获得纯净、稳定的直流输出。嵌入式系统采用C8051F320为主控芯片,通过ADC监测、智能判断、实时...     

一种U型开槽的平面倒置F型双频微带天线

提出一种新型U型开槽的平面倒置F型双频微带天线(PIFA)，该天线利用单馈点同轴线馈电，辐射贴片尾端折叠的设计方式，其结构实现了微带天线在无线通信中小型化双频段工作的要求。利用著名的ANSOFF公司的仿真软件HFSS8．0(High Frequency Structure Simulator)进行仿真设计和优化，最终仿真设计了一副适用于GSM900MHz／DCS1800MHz通信系统的微带天线。     

曲折臂形式的阿基米德螺旋天线小型化研究

把阿基米德螺旋天线的天线臂设计成曲折线的形式,以延长天线臂的电长度,从而达到小型化的目的.对几种不同折线方式的天线进行了仿真,选取一种最佳形式,对其进行了优化,并给出了一种宽频带双面微带线巴伦的设计方法.仿真与实验结果表明:在0.8～4.0GHz频段,与经典阿基米德螺旋天线的结果相比,天线的口面面积减小27%时,仍具有良好的阻抗特性、轴比特性和增益特性.     

一种基于双场效应管S1_S2620的一键多功能控制

随着电子技术的迅猛发展，产品体积微型化，在仪器仪表及各种设备端口的智能化控制中应用越来越广泛。针对这一需求，本文利用一个双场效应管STS2620、一个MCU的两个I／O口、一个微动开关、一个双二极管和两个电阻，设计了一种基于双场效应管STS2620的一键多功能控制电路，能够轻松实现一键开关机等控制功能。     

集成pH－ISFET／压力传感器的研究

基于ＳＤＢ／ＳＯＩ材料和硅微机械加工技术，提出了一种含微参比电极和择优差分补偿单元的背面引线ＰＨ－ＩＳＦＥＴ／压力传感器的新结构。并且设计了高稳定的可调芯片自恒温系统，以减少硅材料对温度敏感的效应。这种结构既方便地实现敏感元和信号处理电路的完全隔离，又有效地改善了敏感特性和稳定性。初步实验结果证实了新结构设计是成功的。     

氨制冷新技术及其进展

氨具有良好的热物性和传输特性,是CFCs与HCFCs理想的替代工质。本文介绍了当今氨在制冷空调领域应用的新技术,NH3/CO2复叠制冷技术、氨用CO2载冷技术、NH3冷水机组等,另外,本文还从安全可靠、高效、小型化和自动化等方面阐述了氨制冷技术的发展趋势。我国的氨制冷技术的发展较为缓慢,可靠性和先进性与国外差距较大,必须加强氨制冷技术的研发力度,促进我国氨制冷技术的发展。     

基于分形的小型化宽频带微带天线设计

结合分形理论的优点,仿真设计了2种基于分形技术的微带天线。这2种天线均采用正六边形分形迭代结构,分别使用微带线和共面波导馈电。通过数值仿真,对天线的阻抗特性和方向图进行了研究,结果表明这2种分形天线的阻抗带宽均达到了90％左右,并且在整个工作频段内具有良好的辐射方向性。同时分形结构的引入,实现了天线的小型化。     

Minimizing manufacturing costs for thin injection molded plastic components

Minimizing the cost of manufacturing a plastic component is very important in the highly competitive plastic injection molding industry. The current approach of R&D work focuses on optimizing the dimensions of the plastic component, particularly in reducing the thickness of the component during product design, the first phase of manufacturing, in order to minimize the manufacturing cost. This approach treats the component dimensions established in the product design phase as the given input, and uses optimization techniques to reduce the manufacturing cost of mold design and molding for producing the component. In most cases, the current approach provides the correct solution for minimizing the manufacturing cost. However, when the approach is applied to a thin component, typically when miniaturizing products, it has problems finding the true minimum manufacturing cost. This paper analyses the shortcomings of the current approach for handling thin plastic components and proposes a method to overcome them. A worked example is used to illustrate the problems and compare the differences when using the current approach and the new method proposed in the paper.