Circuit theory based analysis of CMUT arrays with very large number of cells

Abstract

We have recently developed a circuit theory based method to analyze large CMUT arrays and shown that mutual acoustic interactions significantly influence the transducer performance. We connect each cell in the array to a radiation impedance matrix that contains the mutual radiation impedance between every pair of cells, in addition to their self radiation impedances. However, efficient analysis of very large arrays is challenging, which may become computationally cumbersome. To partition the problem, we electrically drive a single element in the array and keep the rest undriven but biased and with their electrical ports terminated with a load. The radiation impedance matrix can be partitioned and rearranged to represent these loads in a reduced form. In this way, only the driven element can be simulated by coupling its cells through this reduced impedance matrix. This method considerably reduces the number of cells and the size of the original radiation impedance matrix at the expense of calculating the inverse of a large complex symmetric matrix. © 2013 IEEE.