Abstract — Experimental and theoretical evidence of
silicon substrate ringing in microfabricated ultrasonic
transducers is presented. This ringing is clearly observed
in immersion transducers with a 650 μm thick substrate at
7 MHz and harmonics. An analytical model of the ringing
is introduced, and simulations based on the model are
shown to agree with experimental observation.
Experimental results are further compared to simulations
carried out in time-domain, large-scale PZFlex models and
qualitative agreement is demonstrated. The insights gained
from the simulations and experiments are used to design
and fabricate a device whose ringing mode is eliminated
with a backing layer.