Dissertation > Excellent graduate degree dissertation topics show

Study on the Closed Loop Self-excited Detection Circuit for Thermally Excited MEMS Resonator

Author: LiuZhen
Tutor: DongLinZuo
School: Hangzhou University of Electronic Science and Technology
Course: Microelectronics and Solid State Electronics
Keywords: Micromechanical Resonator Closed Loop Self-excited System Phase Lock Loop Zero Phase Difference
CLC: TP212.1
Type: Master's thesis
Year: 2011
Downloads: 27
Quote: 0
Read: Download Dissertation

Abstract


Micro-mechanical resonant sensor is an important micro-sensor. In addition to the advantages of the ordinary silicon micro-machined sensors with small size, light weight, low cost, power consumption and easy integration, the micro-mechanical resonant sensor has high sensitivity, quasi-digital signal output and strong anti-interference ability. The closed-loop self-excitation and detection circuit is one of the most important technologies in developing the micro-resonant sensors, which can enhance the measurement accuracy and speed of the resonant frequency, expand the measurement range and improve the system dynamic characteristics.Based on the open-loop characteristics test and employing the precise frequency selecting and accurate frequency tracking performance of the PLL, a closed-loop self-excitation and detection circuit was developed in this paper, including low-noise differential amplifier, constant delay band-pass filter, phase shifter changing the phase from 0°to 180°, waveform converter transforming the sine to square, frequency divider, PLL with precise frequency selecting and accurate frequency tracking function and amplitude adjustment circuit. The detection system achieved closed-loop self-excited and high-precision measurement of the resonant frequency.The detection circuit’s phase change caused by the frequency offset is a key factor influencing the stability and reliability of test results. In order to eliminate the phase change of the PLL caused by the frequency offset, the paper took advantage of relationship between the steady-state phase difference and the PLL loop filter transfer function and gave an optimization of the PLL circuit based on waveform generator MAX038 to realize frequency tracking function at the fixed phase difference. The PLL circuit, with simple structure and continent parameter selection, can achieve frequency and phase synchronization tracking of transmit signal.After analysis, simulation and debugging of each circuit unit, the design principles of each circuit unit were put forward, and the closed loop self-excited detection circuit for thermally excited MEMS resonator was developed. The closed-loop test result of thermally excited and piezoresistive detection double layers micro-cantilever resonator made of SiO2 and Si shows that the frequency stability of this system can achieve 0.1 Hz/h, so we can get the conclusion that the closed-loop self-excited system has high measurement precision and stability.

Related Dissertations

  1. Development of K-band phase-locked source,TN74
  2. Design and Implementation of miniature wireless video transmission system,TN919.8
  3. Software Design for 10kW Micro-grid Inverter Based on DSP,TM464
  4. Study of Frequency Stabilizing and Phase Locking for Diode Lasers,TN248
  5. Research on GPS Signal Tracking Under High Dynamic Condition,P228.4
  6. Research on Miniature Millimeter-wave Frequency Synthesis Technology,TN74
  7. SDH optical interface board design and lock-in technique,TN914.332
  8. Harmonic Analysis and Suppression Methods Study of Cycloconverter Synchronous Motor Drive System,TM341
  9. Research on Dual-loop Control and Parallel Operation Technique for High Frequency UPS,TN86
  10. L-band high purity frequency source,TN74
  11. Television carrier frequency precision offset design,TN74
  12. A Method of Harmonic Current Detection for Single-Phase Circuit,TM933.1
  13. Design and Research of CP and LPF for PLL,TN713.4
  14. Research on GPS Synchronous Time System for Power System Based on PLL Structure,TM76
  15. Design of a Spread‐Spectrum Clock Generator for DisplayPort Standard,TN79
  16. The Design and Realization of Transmitter Based on RF Communication System,TN830
  17. Research on Improving Performance of Ultrasonic Flowmeter,TH814
  18. The Study of Acoustic Resonance Phenomenon for 4KW HID Lamps,TM923.32
  19. Development of microwave Chirp source,TM935.1
  20. Research on Polarization Diversity and Combining Based on FPGA,TN851.5

CLC: > Industrial Technology > Automation technology,computer technology > Automation technology and equipment > Automation components,parts > Transmitter ( converter),the sensor > Physical sensors
© 2012 www.DissertationTopic.Net  Mobile