Dynamic real-time focusing of ultrasonic transducer arrays in sequential mode

A technique for dynamic real time focusing of ultrasonic transducer arrays is introduced. This paper assumes a linear transducer array operating in the sequential mode. In this case, the elements are fired sequentially, one at a time, all elements receive in parallel. The returns are integrated coherently on the basis of equal geometric phase to synthesize the echoes of an array twice as large. Dynamic focusing is accomplished at any depth through electronic correction of the dominant quadratic phase terms. For this purpose a second order Taylor series expansion of the phase is used