MEMS BASED DOPPLER VELOCITY MEASUREMENT SYSTEM.
design, fabrication, modeling and characterization of a capacitive micromachined
ultrasonic transducer (cMUT) based in-air Doppler velocity measurement system using a 1
cm2 planar array are described. Continuous wave operation in a narrowband was chosen in
order to maximize range, as it allows for better rejection of broadband noise. The
sensor array has a 160-185 kHz resonant f... read morerequency to achieve a 10 degree beamwidth. A
model for the cMUT and the acoustic system which includes electrical, mechanical, and
acoustic components is provided. Furthermore, characterization of the cMUT sensor with a
variety of testing procedures is provided. Laser Doppler vibrometry (LDV), beampattern,
reflection, and velocity testing characterize the performance of the sensors. The sensor
is capable of measuring the velocity of a moving specular reflector with a resolution of
5 cm/s, an update rate of 0.016 second, and a range of 1.5
Thesis (Ph.D.)--Tufts University, 2012.
Submitted to the Dept. of Mechanical Engineering.
Advisor: Robert White.
Committee: Paul DeBitetto, Jason Rife, Peter Sherman, and Jeffrey Hopwood.
Keywords: Mechanical engineering, Acoustics, and Electrical engineering.read less