Micro-oven Based Temperature Compensation Systems for MEMS Oscillators - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Micro-oven Based Temperature Compensation Systems for MEMS Oscillators write by James Christian Salvia. This book was released on 2010. Micro-oven Based Temperature Compensation Systems for MEMS Oscillators available in PDF, EPUB and Kindle. Almost all imaginable electronic devices in common use today, including cell phones, laptops, music players, cameras, televisions, automobiles, appliances, and wristwatches, rely upon timing references of some kind. Traditionally, the timing references used in all of these applications have relied upon the same technology: quartz crystal oscillators. However, Microelectromechanical Systems (MEMS) oscillators have become a viable option and are replacing quartz in segments of the timing reference market. In part, this paradigm shift is based upon the improved size, cost, and reliability of MEMS solutions. Unfortunately, the temperature stability of MEMS oscillators is inferior to that of compensated quartz oscillators, and this is one of several shortcomings that have precluded the use of MEMS references in some high precision applications like wireless communication and navigation. This thesis presents the fundamental concepts behind MEMS resonator and oscillator operation as well as an overview of previously established temperature compensation schemes for MEMS devices. Details are provided on the MEMS technology used throughout this work, including Double Ended Tuning Fork (DETF) resonators, "epi-seal" encapsulation, and a variety of associated nonideal behaviors. Measurement data from several MEMS prototypes is also provided along with an overview of the concepts of phase noise and Allan variance. Two MEMS interface circuits are demonstrated. The first is an integrated transimpedance amplifier (TIA) designed specifically to interface with MEMS devices that exhibit very large motional impedance. The TIA consists of a capacitive-feedback current amplifier that drives current into an active load to obtain a 56 M[omega] transimpedance gain, 1.8 MHz bandwidth, phase response near 0 degrees, and 65 fA/[square root]Hz input-referred noise. The TIA was fabricated in 0.18 [mu]m CMOS technology and dissipates 436 [mu]W from a 1.8 V supply. The second circuit is a printed circuit board (PCB) implementation of a fully functional 1.2 MHz MEMS oscillator, including automatic level control. This PCB-based oscillator was used to flexibly test the MEMS prototypes used throughout the remainder of the thesis. Two active temperature compensation schemes that significantly improve the temperature stability of silicon MEMS oscillators are also demonstrated. Both schemes rely on micro-oven based compensation, using micro-scale thermal isolation and heating to maintain a MEMS resonator at a constant elevated temperature. The power consumption for the micro-ovens used in this work was in the range of 9 to 15 mW for a 100 degrees C operation range. The first temperature compensation scheme, called "Q(T)-based temperature compensation, " uses resonator quality factor as a proxy for temperature in a closed loop feedback system. This system achieved frequency stability of +/-25 ppm over a temperature range of 0 to 70 degrees C with a single-point calibration or +/-1 ppm with a multi-point calibration, but suffered from the limitations of considerable calibration overhead and poor long term stability. In particular, the Q(T) system's sensitivity to the analog gain of the components in the temperature sensing feedback path proved to be a major hindrance to this system's performance. The second scheme, called "[delta]f-based temperature compensation, " uses a phase lock loop and an integrated micro-oven to achieve temperature compensation. The phase lock loop monitors the difference frequency between two resonators with different temperature coefficients. This difference frequency provides a high resolution measurement of the resonators' temperature and is compared to a reference frequency derived from one of the resonators. Negative feedback is then used to drive the difference between the difference frequency and the reference frequency to zero by applying heat to the micro-oven. This procedure ensures that the micro-oven is held at a constant temperature despite variations in ambient temperature, thereby allowing the [delta]f system to maintain sub-ppm frequency stability under transient temperature conditions from -20 to 80 degrees C and part-per-billion level Allan deviation in an uncontrolled environment. Additional calibration is shown to reduce the steady-state temperature stability to the range of +/-60 ppb. It is hoped that this novel temperature scheme may facilitate the use of low power, low cost, space saving MEMS oscillators in a new arena of high precision timing reference applications.
Issues in Nanotechnology and Micotechnology: Engineering, Fabrication, and Structural Research: 2011 Edition
Issues in Nanotechnology and Micotechnology: Engineering, Fabrication, and Structural Research: 2011 Edition - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Issues in Nanotechnology and Micotechnology: Engineering, Fabrication, and Structural Research: 2011 Edition write by . This book was released on 2012-01-09. Issues in Nanotechnology and Micotechnology: Engineering, Fabrication, and Structural Research: 2011 Edition available in PDF, EPUB and Kindle. Issues in Nanotechnology and Micotechnology: Engineering, Fabrication, and Structural Research: 2011 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Nanotechnology and Micotechnology—Engineering, Fabrication, and Structural Research. The editors have built Issues in Nanotechnology and Micotechnology: Engineering, Fabrication, and Structural Research: 2011 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Nanotechnology and Micotechnology—Engineering, Fabrication, and Structural Research in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Nanotechnology and Micotechnology: Engineering, Fabrication, and Structural Research: 2011 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.
Micromachined Circuits and Devices
Micromachined Circuits and Devices - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Micromachined Circuits and Devices write by Shiban Kishen Koul. This book was released on 2022-02-07. Micromachined Circuits and Devices available in PDF, EPUB and Kindle. This book presents the design of different switching and resonant devices using the present state-of-the-art radio frequency (RF) micromachining (MEMS) technology. Different topologies of MEMS switches have been discussed considering optimum performances over microwave to millimeter wave frequency range. Wide varieties of micromachined switching networks starting from single-pole-double-throw (SPDT) to single-pole-fourteen-throw (SP14T) are discussed utilizing vertical and lateral actuation movements of the switch. Different transduction mechanisms of micromachined resonators are highlighted that includes capacitive, piezoelectric, and piezoresistive types. The book provides major design guidelines for the development of MEMS-based digital phase shifters, tunable filters, and antennas with extensive measurement data. Apart from the radio frequency (RF) requirements, an extensive guideline is given for the improvement of the reliability of micromachined switches and digital phase shifters where multiple switches are operating simultaneously. It takes multiple iterations and extensive characterizations to conclude with a reliable MEMS digital phase shifter, and these aspects are given one of the prime attentions in this book. Detailed performance analysis of metamaterial inspired MEMS switches is then discussed for application in millimeter wave frequency bands up to about 170 GHz. The book concludes with future research activities of RF MEMS technology and its potential in space, defense, sensors, and biomedical applications.
Development of CMOS-MEMS/NEMS Devices
Development of CMOS-MEMS/NEMS Devices - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Development of CMOS-MEMS/NEMS Devices write by Jaume Verd. This book was released on 2019-06-25. Development of CMOS-MEMS/NEMS Devices available in PDF, EPUB and Kindle. Micro and nano-electro-mechanical system (M/NEMS) devices constitute key technological building blocks to enable increased additional functionalities within Integrated Circuits (ICs) in the More-Than-Moore era, as described in the International Technology Roadmap for Semiconductors. The CMOS ICs and M/NEMS dies can be combined in the same package (SiP), or integrated within a single chip (SoC). In the SoC approach the M/NEMS devices are monolithically integrated together with CMOS circuitry allowing the development of compact and low-cost CMOS-M/NEMS devices for multiple applications (physical sensors, chemical sensors, biosensors, actuators, energy actuators, filters, mechanical relays, and others). On-chip CMOS electronics integration can overcome limitations related to the extremely low-level signals in sub-micrometer and nanometer scale electromechanical transducers enabling novel breakthrough applications. This Special Issue aims to gather high quality research contributions dealing with MEMS and NEMS devices monolithically integrated with CMOS, independently of the final application and fabrication approach adopted (MEMS-first, interleaved MEMS, MEMS-last or others).]
Temperature Compensated CMOS and MEMS-CMOS Oscillators for Clock Generators and Frequency References
Temperature Compensated CMOS and MEMS-CMOS Oscillators for Clock Generators and Frequency References - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Temperature Compensated CMOS and MEMS-CMOS Oscillators for Clock Generators and Frequency References write by Krishnakumar Sundaresan. This book was released on 2006. Temperature Compensated CMOS and MEMS-CMOS Oscillators for Clock Generators and Frequency References available in PDF, EPUB and Kindle. The purpose of this dissertation is to explore alternatives to quartz crystal based solutions to system clocking. While quartz has inherent advantages in terms of stability and cost, the inability to manufacture quartz in a standard silicon process impedes goals of miniaturization and system integration. A closer look at clocking requirements reveals widely different specifications for various applications. In addition to traditional CMOS oscillators such as ring and LC oscillators, the recent advent of micromachining technologies and MEMS resonators has provided a miniaturized, silicon alternative to quartz with potentially comparable performance levels. This provides the system designer with an option to make a clocking solution that most suits the system needs.
