Improving CMUT receiving sensitivity using parametric amplification

摘要

This paper presents a signal controlling method for improving the receiving sensitivity of CMUTs using the concept of parametric amplification. An extra AC pumping voltage at twice the frequency of the incoming acoustic signal is superimposed on the conventional DC receiving bias. Finite element analysis and numerical simulation show at least a 7dB improvement for a single CMUT in an infinite medium in response to a sinusoidal acoustic source. The level of amplification is sensitive to the phase angle and the amplitude of the pumping voltage. Improvement is also shown for a pulsed acoustic source and low Q factor CMUTs.