Atalar, AbdullahKöymen, Hayrettin2016-02-082016-02-082014-09http://hdl.handle.net/11693/27857Date of Conference: 3-6 Sept. 2014Conference name: 2014 IEEE International Ultrasonics SymposiumWe determine the response of individual cells of a CMUT array immersed in water using the small-signal equivalent circuit of a single cell and radiation impedances. Using a numerically efficient technique, we are able to simulate large arrays. The results indicate the presence of resonances at low frequencies where Rayleigh-Bloch waves are excited on the surface of the array. Reflections from the edges cause standing-wave patterns. Above the cut-off frequency of Rayleigh-Bloch waves, no standing-wave pattern exists. However, there is nonuniformity among cell velocities mainly due to unequal radiation impedance seen by the cells. Rayleigh-Bloch waves and nonuniformity in cell velocities do not cause a significant degradation in the point spread function, but the oscillations extend the duration of impulse response, limiting the dynamic range. © 2014 IEEE.EnglishCellsElastic wavesHeterojunction bipolar transistorsImpulse responseOptical transfer functionDynamic rangeIndividual cellsLarge arraysNon-uniformitiesNonuniformityRadiation impedanceSmall signal equivalent circuitStanding wave patternsCytologyConference Paper10.1109/ULTSYM.2014.0073