有线无源PDC-SiCN陶瓷基温度传感器的设计与制备

针对航空发动机高温恶劣环境监测对耐高温传感器的需求,提出采用新型耐高温聚合物先驱体陶瓷(PDC-SiCN陶瓷)为温敏介质材料,制备被动式有线无源微波温度传感器,实现温度信息的有线无源传输。以PDC-SiCN陶瓷为填充介质,金属银作为表面层,形成谐振器;以共面波导线和共面天线为传输线,实现微波信号的传输;在谐振器的侧面开槽,实现宽频激励信号和谐振信号在传输线和谐振器之间的传输。采用HFSS软件进行结构尺寸的仿真和优化,设计出了满足最大传输效率的被动式有线无源PDC-SiCN耐高温温度传感器结构。通过以上结构设计,制备出了有线无源温度传感器。结果表明,所设计传感器的工作频率为10.16GHz,依据材料的变化特性该传感器可实现频率在500 MHz变化范围内的测量。     

基于极化变换谐振器的远距无芯片RFID湿度传感器设计

提出了一种用于远距离传感的无芯片RFID湿度传感器的设计.设计采用极化变换谐振器,用于减小周围环境对标签响应的影响,提高了传感器的可靠性.传感器标签集成了可实现极化变换的双螺旋条带和四组弯曲哑铃形条带,分别作为湿度传感谐振器和编码谐振器,能够在3.1 GHz~10.6 GHz的超宽带频率范围内产生5个谐振峰.传感谐振器表面涂覆的PVA材料层在湿度变化时影响谐振频率,实现湿度传感.谐振器标签布局紧凑,便于组成阵列形式以提高其雷达散射截面(RCS),实现远距离传感.仿真和实测结果表明,该传感器在1.4 m的阅读距离时可实现较为灵敏的湿度传感功能.传感器整体性能良好,具有较广的应用前景.     

新型微波介质陶瓷材料与元件的研制

报告本课题组承担的863计划项目“新型微波介质陶瓷材料与元件的研制”，在实验工作中不仅采用传统的固相反应法而且利用共沉淀和水热合成等溶液反应技术，还采用凝胶浇注成型复杂形状的微波陶瓷元件，并利用流延成型技术制备大尺寸微波集成陶瓷基板等；研制成功具有高电容率和品质因子并接近于零的谐振频率温度系数的系列化微波介质陶瓷；开发成功多种微波介质元器件，包括：介质谐振器、介质滤波器、GPS片式天线、微波电容器、通信电缆滤波接头和微波集成基板等。     

用于挥发性有机化合物探测的微悬臂梁传感器

在研制成功的用于化学气体探测的热驱动微悬臂梁谐振器的基础上,提出了基于这种微悬臂梁谐振器,并以聚合物涂层作为挥发性有机化合物吸附敏感层的谐振式气体传感器.利用3种聚合物材料：聚氧化乙烯（PEO）、聚乙烯醇（PVA）和聚乙二醇乙醚醋酸酯（PEVA）,在微悬臂梁谐振器上制备气体敏感层,探测6种挥发性有机化合物：甲苯、苯、乙醇、丙酮、己烷和辛烷.通过有限元分析估计了聚合物涂层的工作温度.用喷射法制备了PVA和PE-VA涂层,用点滴法制备了PEO涂层.测试了传感器的开环幅频特性,实验检测了气体传感器的谐振频率变化与分析物蒸气浓度的关系以及传感器对相对湿度的响应,分析了传感器的灵敏度和线性度.实验结果表明,这种涂覆聚合物敏感层的热驱动微悬臂梁谐振器为探测挥发性有机化合物提供了良好的平台.根据实验结果,可开发几种基于不同聚合物敏感层的高灵敏度微型气体传感器.     

碳纳米管电导率的介质谐振器法测量研究

采用介质谐振器法测量碳纳米管在微波频段下的电导率.本文介绍了利用介质谐振器法测量碳纳米管电导率的理论模型和测量装置,给出了利用该装置测得的一系列测量结果,并对其不确定度进行了分析.     

微波陶瓷介电性能自动测试系统

介绍了平行板介质谐振器法测试微波介质陶瓷的基本原理,建立一套基于该方法的自动测试系统并对测试结果进行分析.使用表明该自动测试系统稳定、重复性好、测试效率高.测试系统的建立为微波介质陶瓷的研究提供了有效测试手段.     

通信用微波介质谐振器陶瓷的系列化开发与研究进展

微波通信系统离不开滤波器和振荡器。前者是这种系统的肾,起频率过滤器的作用,而后者则是心脏,它发出振荡信号。如果这两个器件不能小型化,整个微波电路的集成化、小型化也就不可能实现。它们都是由介质谐振器制成的,因此,归根到底,微波电路的全集成化,极大地依赖于微波介质谐振器材料的开发。 微波是指从300MHz到3OGHz之间的频段。划分为UHF,L,S,X,Ku等波段,相应于0.3～1、1～2、3～4、4～8、8～12GHz直到毫米波。微波介质谐振器首先在70年代末期被用于空间技术,然后被推广到民用通信。任何微波频段都是军民两用的,因     

低定量水份测量装置

针对造纸行业定量较轻的薄纸,用微波法测量,研制成用单面开槽波导作为传感元件的传感器及其测量电路用微波衰减法测定水份,可以在线测量（定量200g--600g／m2纸的水份瞬时平均值,但遇到纸的定量在100g／m2以下,单面开槽波导传感器就不适合纸页通过波导管测量面上,故吸收微波功率小,灵活度低,而信号处理电路需要放大倍数高,易产生电路不稳定,因此我们采用了一种非接触式薄纸测量水份装置,本文着重介绍一种专门适用于低定量薄纸水份测量的非接触式波导传感器     

微波介质谐振器介电参数的测量

本文讨论了微波介质谐振器介电参数测试技术。用研制的测试装置对多个介质样品进行了实测，结果表明，本文的分析与实际值是吻合的。该测试技术可对微波介质谐振器的复介电常数进行迅速、准确、可靠、宽频带、无损伤、自动化和批量检测，具有较强的实用性。     

磁电层状复合结构及其器件应用

磁电层状复合结构是层状铁电相与铁磁相的复合,该层状结构同时具有铁电性和铁磁性,呈现出磁电耦合效应.可以利用此复合结构制作具有磁电调、电可调双重可调特性的微波器件,拥有潜在而广阔的应用前景.主要介绍了磁电层状复合结构在微波延迟线、谐振器及移相器等方面的应用.     

常用航空航天传感器成像特点探讨

本文先从摄影型、线阵式和光机式分析了星载光学传感器成像特点,接着以DMC、UCD、ADS40和LIDAR为例讨论了机载光学传感器的特点,然后介绍了微波传感器的特点,最后对一种特殊的光学传感器——成像光谱仪进行了介绍.     

Continuous Terrestrial Positioning Based on Microwave Displacement Sensors

Measurement Techniques - An autonomous positioning system is proposed for navigation of terrestrial transport based on microwave radar displacement sensors. An algorithm for direct and continuous...     

Embedded Sensors in Rubber and Other Polymer Components

Abstract: Many polymer components are susceptible to catastrophic failure or are critical to the performance of the products they comprise. Because of this, the capability to monitor structural failures or performance reduction in these components is beneficial. It is difficult to fabricate sensors for polymer components because they often have complex shapes or are assembled in isolated locations. To solve this problem, micro‐scale electronic sensors, embedded within polymer components, were developed at Purdue University. Conductive polymer materials were used as the primary sensing element in the sensors. Testing results reveal that embedded sensors in polymer components can successfully indicate significant signal changes more than 100 loading cycles prior to catastrophic failure. Multiple sensing methods and applications have been tested and more are being researched. These findings may open doors for future polymer sensors that can improve safety and provide useful measurements for polymer components.     

Recent developments in lightwave network analysis

The widespread use of photonic systems having microwave modulation bandwidths, coupled with the inclusion of photonic components in microwave and millimetre-wave systems, is creating a demand for efficient characterization techniques. In particular, new tools will be required for the measurement of fundamental quantities such as the microwave frequency response, bandwidth, gain and return loss of microwave photonic components. However, existing lightwave measurement techniques are primitive when compared with conventional RF and microwave network analysis. This paper provides a review of the theory and techniques used for the small-signal characterization of microwave photonic components. State-of-the-art architectures for lightwave network analysers and the two-port calibration techniques are described     

Passive microwave remote sensing of the atmosphere and ocean

The microwave remote sensing experiments conducted during the last decade using airborne and spaceborne sensors are now evolving as operational spacecraft observation systems. Microwave sounding unit (MUS) onboard TIROS-N regularly provides global atmospheric temperature profile required for numerical weather prediction. The monitoring of composition profile and geophysical parameters from space platform is now a reality and holds a great promise for future meteorological and oceanographic research. This review paper summarises the recent advances and future opportunities in passive microwave radiometry. Indian microwave remote sensing programme and achievements to date are also described.     

Optical infrared remote sensors

Various kinds of remote sensors, active and passive, covering a significant part of the electromagnetic spectrum from ultraviolet to microwave regions have been developed for observation of earth for the purpose of resource survey. Several of the widely used remote sensors (in the visible and infrared region) beginning from photographic cameras to the modern-day linear imaging self-scanning sensors have been described with reference to the state-of-the-art, critical parameters, performance limitations etc. User requirements with regard to various system parameters of the remote sensors have been analysed. Some future trends in the development of remote sensors for spaceborne applications have been touched upon.     

气液两相低温流体空泡率测量技术及其进展

对目前几种用于测量低温气液两相流空泡率方法的基本原理、传感器结构及国内外研究情况进行了综述,包括辐射法(射线吸收法)、微波法、射频法、电容法,分析了4种方法的优缺点,在比较4种方法的基础上,提出了目前采用电容传感器测量气液两相低温液体空泡率的优势及设计准则.     

Vibration-induced PM and AM noise in microwave components

The performance of microwave components is sensitive to vibrations to some extent. Aside from the resonator, microwave cables, and connectors, bandpass filters, mechanical phase shifters, and some nonlinear components are the most sensitive. The local oscillator is one of the prime performance-limiting components in microwave systems ranging from simple RF receivers to advanced radars. The increasing present and future demand for low acceleration sensitive oscillators, approaching 10?13/g, requires a reexamination of sensitivities of basic nonoscillatory building-block components under vibration. The purpose of this paper is to study the phase-modulation (PM) noise performance of an assortment of oscillatory and nonoscillatory microwave components under vibration at 10 GHz. We point out some challenges and provide suggestions for the accurate measurement of vibration sensitivity of these components. We also study the effect of vibration on the amplitude-modulation (AM) noise.     

微波间隙测量系统研究

针对航空发动机恶劣的现场测试环境,分析了基于微波法进行间隙测量的优点,并描述了微波间隙测试系统的组成和采用微波相位法进行间隙测量的原理,最后,通过对微波叶尖间隙测量系统进行的实验验证,证实了测量系统的有效性,同时分析了测量中的主要影响因素,有助于航空发动机实际测试的应用。     

Radiometric sensor for temperature control of food processing

This paper describes a novel planar antenna sensor created for the purpose of noninvasive temperature measurements using microwave radiometry. In order to improve radiometric measurements in industrial applications, a new generation of sensors is introduced, composed of a metallic sheet. Simulations based upon the method of moments is used both to design and to determine their electromagnetic performances. This paper also describes a radiometric device using these sensors to measure and control the temperature of food products during deep freezing processes. The results and discussions are presented.