Systematic Theoretical Analysis of Dual-Parameters R

This paper systematically studied the simultaneous measurement of two parameters by a LC-type passive sensor from the theoretical perspective. Based on the lumped circuit model of the typical LC-type passive dual-parameter sensor system, the influencing factors of the signal strength of the sensor as well as the influencing factors of signal crosstalk were both analyzed. It is found that the influencing factors of the RF readout signal strength of the sensor are mainly quality factors (Q factors) of the LC tanks, coupling coefficients, and the resonant frequency interval of the two LC tanks. And the influencing factors of the signal crosstalk are mainly coupling coefficient between the sensor inductance coils and the resonant frequency interval of the two LC tanks. The specific influence behavior of corresponding influencing factors on the signal strength and crosstalk is illustrated by a series of curves from numerical results simulated by using MATLAB software. Additionally, a decoupling scheme for solving the crosstalk problem algorithmically was proposed and a corresponding function was derived out. Overall, the theoretical analysis conducted in this work can provide design guidelines for making the dual-parameter LC-type passive sensor useful in practical applications

Development of SiC-LC Resonant Wireless High Temperature Pressure Sensor

高温压力传感器在航天、航空、国防建设、能源开发等领域有广阔应用需求。传统硅材料在高于200℃后机械/电学性能均受到较大影响，无法满足高温应用要求。另一方面，传统高温传感器引线会导致电源、信号电路的温度升高问题，基于LC谐振的无线传感器能实现非接触式测量，达到电性连接、调理电路与高温热源之间物理隔离，提高传感器工作温度和稳定工作时间。因此，本论文提出一种SiC-LC谐振式无线高温压力传感器，主要研究工作如下： (1)根据LC谐振测量原理设计电感内置及电感外置两种敏感元件的结构方案，采用Silvaco软件对本体电容进行对比分析，得出电感内置结构具有本体电容小、谐振信号易于检测、制备工艺难度更低等...High temperature pressure sensor has broad application requirements in aerospace, aviation, national defense construction, energy development and other fields. Silicon material performance is greatly affected in the higher than 200℃ performance, can not meet the requirements of high temperature applications. At present, high temperature sensor will lead to power supply, signal circuit temperature...学位：工学硕士院系专业：航空航天学院_电气检测技术及仪器学号：1992014115289

The design and development of a planar coil sensor for angular displacements

The increased prevalence of wearable sensing devices is accelerating the development of personalised medical devices for monitoring the human condition. The measurement of joint posture and kinematics is particularly relevant in areas of physiotherapy and in the management of diseases. Existing sensors for performing these tasks are however, either inaccurate or too technically complex and obtrusive. A novel approach has been taken to develop a new type of sensor for angular displacement sensing. This thesis describes the development of a series of novel inductive planar coil sensors for measuring angular displacement. The small profile of these sensors makes them ideal for integration into garments as part of wearable devices. The main objective of this work was to design a planar coil topology, based on an inductive methodology, suitable for measuring angular displacements typically observed in finger articulation. Finite Element Method software was initially employed to determine the feasibility of various coil topologies. The planar coils were subsequently manufactured on several types of substrate including rigid printed circuit boards and flexible polyester films incorporating an iron-based amorphous ribbon as the inductive element. A series of experimental investigations involving inductance and stray field measurements, were performed on a range of coil topologies and layered configurations. The resulting data provided information relating sensor performance to positioning of the amorphous element and its overall angular displacement. The main findings showed that inductance change was not frequency dependent in the range (20 – 100) kHz but decreased by up to 15% for large angular displacements when utilising a figure-of-eight coil design. The sensors developed in this work provide significantly better accuracy than current resistive-based flexible sensors. Further refinements to coil design and optimisation of the inductive element’s magnetic properties is expected to yield further improvements in sensor performance providing an excellent platform for future wearable technologies

A High-Yield Microfabrication Process for Sapphire Substrate Pressure Sensors with Low Parasitic Capacitances and 200 C Tolerance

Microelectromechanical systems (MEMS) can offer many benefits over conventional sensor assembly, especially as the desire for smaller and more effective instrumentation escalates in demand. While many industries continually strive for improved sensing capabilities, those invested in natural gas and oil extraction have a particular interest in miniaturized pressure sensing systems. These sensors need to operate autonomously in harsh environment (50 MPa, 125°C) fissures (≤1 cm) with at least 10 bit pressure resolution (≤0.05 MPa). The primary focus of this report is the development of a surface micromachining process to fabricate high performance capacitive pressures sensors, utilizing dielectric substrates to enable extremely low offset and parasitic capacitances and temperature coefficients. In contrast to conventional bulk silicon micromachining methods that use various kinds of etch stops such as electrochemical or dopant selective, dry additive processes are utilized to reduce manufacturing complexity, cost, and material consumption and have gained favor in recent years as the tools have matured. The fabricated devices must meet both pressure sensing and dimensional scaling requirements with a full scale range of ≥50 MPa, resolution of ≤50 kPa (>20 fF/MPa with a system resolution of 1 fF/code), and size of ≤2×1×0.5 mm3. In order to meet these goals while maximizing yield, particular attention has been given to the interplay between equipment limitations and device design. Process and design features have been refined over four process generations that together lead to a capacitance response of >450 fF/MPa over 50 MPa, provide a yield of >80%, permit an extreme span (>1000×) of full scale range designs, and allow automated system assembly. Devices have been tested at pressures and temperatures of up to ≥50 MPa and 200°C, representing downhole environments, demonstrating < 7.0 kPa (< 1 psi) resolution. Devices designed to operate over a much lower full scale range of < 50 kPa (≤350 Torr), representing biomedical applications, have been tested and demonstrate a resolution of < 80 Pa (< 0.6 Torr). Sensor response and design have been validated in the primary use case of autonomous microsystem integration. The system circuity includes a microcontroller, capacitance-to-digital converter, temperature sensor, photodiode, and battery. The readout electronics and sensor are mounted onto a flexible PCB, packaged into stainless steel or ceramic shells, sealed with silicone epoxy to permit pressure transmission while providing environmental protection, and measure < 9×9×7 mm3 in size. The systems have been successfully field tested in a brine well. While the capacitive pressure sensors have been developed primarily for active microsystems, there may be situations where a wired connection to the readout circuitry is not possible. A passive wireless pressure monitoring system utilizing short range inductive coupling has been developed to evaluate the performance of the sapphire substrate sensors for this use case. The passive sensing element consists of the capacitive pressure sensor and an inductor, packaged in a 3D printed biocompatible housing measuring ø12 x 24 mm3. Pressure monitoring within the GI tract has been targeted; an in situ resolution of 1.6 kPa (12 Torr) at 6 cm has been achieved through conductive saline. A practical application of the sensor has been demonstrated in vivo, having been ingested and successfully interrogated in a canine model to monitor stomach pressure for over two days.PHDElectrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/149856/1/acbenken_1.pd

Abstracts on Radio Direction Finding (1899 - 1995)

The files on this record represent the various databases that originally composed the CD-ROM issue of "Abstracts on Radio Direction Finding" database, which is now part of the Dudley Knox Library's Abstracts and Selected Full Text Documents on Radio Direction Finding (1899 - 1995) Collection. (See Calhoun record https://calhoun.nps.edu/handle/10945/57364 for further information on this collection and the bibliography). Due to issues of technological obsolescence preventing current and future audiences from accessing the bibliography, DKL exported and converted into the three files on this record the various databases contained in the CD-ROM. The contents of these files are: 1) RDFA_CompleteBibliography_xls.zip [RDFA_CompleteBibliography.xls: Metadata for the complete bibliography, in Excel 97-2003 Workbook format; RDFA_Glossary.xls: Glossary of terms, in Excel 97-2003 Workbookformat; RDFA_Biographies.xls: Biographies of leading figures, in Excel 97-2003 Workbook format]; 2) RDFA_CompleteBibliography_csv.zip [RDFA_CompleteBibliography.TXT: Metadata for the complete bibliography, in CSV format; RDFA_Glossary.TXT: Glossary of terms, in CSV format; RDFA_Biographies.TXT: Biographies of leading figures, in CSV format]; 3) RDFA_CompleteBibliography.pdf: A human readable display of the bibliographic data, as a means of double-checking any possible deviations due to conversion

Magnetic Hybrid-Materials

Externally tunable properties allow for new applications of suspensions of micro- and nanoparticles in sensors and actuators in technical and medical applications. By means of easy to generate and control magnetic fields, fluids inside of matrices are studied. This monnograph delivers the latest insigths into multi-scale modelling, manufacturing and application of those magnetic hybrid materials

Magnetic Hybrid-Materials

Externally tunable properties allow for new applications of suspensions of micro- and nanoparticles in sensors and actuators in technical and medical applications. By means of easy to generate and control magnetic fields, fluids inside of matrices are studied. This monnograph delivers the latest insigths into multi-scale modelling, manufacturing and application of those magnetic hybrid materials