Designing an efficient wide bandwidth single cell CMUT for airborne applications using nonlinear effects

In this work, we propose a new approach to obtain wider bandwidth for an airborne capacitive micromachined ultrasonic transducer (CMUT) cell without sacrificing sensitivity. This is done through employing the stiffening effect created by the atmospheric pressure. We use an equivalent lumped element circuit to model both electrical and mechanical properties of an airborne CMUT cell. We determine the lowest achievable mechanical quality factor of the cell in the elastically linear region. By extending the analysis to elastically nonlinear region, a significantly lower mechanical quality factor is obtained.