Analytical design of circular CMUT cells in immersion

Abstract

Analytical design of Capacitive Micromachined Ultrasound Transducers givesinsight on the effect of geometrical parameters and material properties of CMUTon its performance. I. Wygant et al. presented at IEEE IUS 2009 equations fordesign of circular CMUT cell based on desired resonance frequency, qualityfactor and pull-in voltage. In this paper, we extend their work by capturing theimpact of spring softening on resonance frequency. We propose a simple methodto calculate CMUT 3-dB bandwidth in immersion utilizing equivalent circuit.Finally, A design flow is presented based on optimizing CMUT performance inimmersion. Design of 50 MHz CMUT is illustrated using analytical approach. FEMresults supports the validity of proposed design equations and designmethodology in shown cases. © 2010 IEEE.