Weighted least-squares pulse-shaping filters with application to ultrasonic signals

The resolution of adjacent surfaces in medical ultrasonic imaging depends on the duration of a reflected echo. By shaping the excitation signal of the transducer, this duration can be decreased. The authors present a method for effective calculation of the excitation pulse by introducing a weighting function that defines the resolution. A class of filter is obtained that includes the least-mean-squares filter, the pure inverse filter, and the matched filter. The method is demonstrated in an application that increases the resolution of an ultrasonic transducer.<>