Dissertation > Excellent graduate degree dissertation topics show

Micro audio directional electrical characteristics of the transducer and drive circuit design

Author: ZhangYing
Tutor: XuLiMei
School: University of Electronic Science and Technology
Course: Mechanical and Electronic Engineering
Keywords: audio beam transducer equivalent circuit power amplifier impedance matching
CLC: TB552
Type: Master's thesis
Year: 2010
Downloads: 62
Quote: 0
Read: Download Dissertation

Abstract


Audio beam system can emit high directional audible sound due to the nonlinear interaction of ultrasound in air. The main target of this thesis is to produce a micro audio beam system used in mobile multimedia for portable communication equipments. As piezoelectric Micromachined Ultrasonic Transducer (pMUT) is the key part of audio beam system, it is necessary to analyze its equivalent circuit and to calculate its electrical parameters. Meanwhile, based on the electrical analysis of transducer array, the driving circuit of system was devised.The theoretical basis of audio beam technology originates from directivity principle and ultrasound nonlinear theory. According to these, the scheme of micro audio beam system is proposed. Then, based on energy equivalent theory, the electromechanical equivalent model of pMUT could be built and the value of elements in this model may be calculated by introducing effective electro-mechanical coupling coefficient, electro-elastic constants and structure size of pMUT. In this case, the relationship between frequency and admittance is easy to established, whose accuracy would be verified by experiment. In order to actuating the transducer to vibration and sound production, a driving circuit with functions of power amplifier, filter and impedance matching is designed. In addition, considered that the transducer appears capacitance in working, the driving circuit should be able to drive big capacitance load.With the purpose of testing the performance of driving circuit and the directivity of system, a series of experiments are performed. Based on the analysis of testing results, it is concluded that the circuit is capable of driving load with high efficiency and low distortion, and the directivity of micro audio beam system is ideal with no obvious side lobes.

Related Dissertations

  1. The Equivalent Circuit Model of Radial Vibration Mode Piezoelectric Transformer and Its Application,TM406
  2. Research and Improvement of Multi-Level Modulation Self-Adaptive Digital Predistortion Algorithm,TN722.75
  3. Design of Digital Predistorter for RF Power Amplifier Based on FPGA,TN722.75
  4. A Study of PAPR Reducing in the OFDM Underwater Acoustic Communication Systems,TN919.3
  5. The Research of Single Patchand Compact Dual-Band Microstrip RFID Antenna,TN822
  6. Study on Ultrasonic Testing Technology for Motor Bolt in Service,TM31
  7. Study on a New Novel Avalanche Photodiode for Suppression of Edge Pre-breakdown,TN364.2
  8. High-frequency surface acoustic wave filters Preparation of nano-imprint technology,TN713
  9. 100-400MHz broadband power amplifier design and implementation,TN722.75
  10. Medical ultrasound imaging Piezoelectric transducer probe studies,TN384
  11. Metal plate surface electromagnetic ultrasonic flaw detection technology research,TG115.284
  12. Composite cage rotor induction motor starting performance of the design and research,TM343
  13. RFID antenna research and design,TN820
  14. Ultrasonic borehole Imager Research,TP274
  15. Acoustic levitation and abrasive polishing apparatus developed flow field,TG580.692
  16. Research of Power and Data Wireless Transmission System for Visual Prosthesis,R318.1
  17. Research on Miniaturized Folded Waveguide Power Dividers,TN626
  18. Research on Traveling Wave Usm Using Cantilevel Type Bending Mode Sandwich-Transducer,TM359.9
  19. Research on Ultrasonic Driver with Four Driving Feet Using Longitudinal Compound Transducer,TM359.9
  20. Research on Data Acquisition System of Digital Substation and the Protection Theory for Transformer Based on It,TM76;TM63
  21. Research on Calibration Technology of Electronic Transformers,TM45

CLC: > Industrial Technology > General industrial technology > Acoustic engineering > Ultrasonic Engineering > Ultrasonic transducer
© 2012 www.DissertationTopic.Net  Mobile