Delay generator for phased array ultrasound beamformer

Abstract

A delay generator for a beamformer in a phased array ultrasound imaging system is provided. The beamformer processes received signals from an array of transducer elements to form a receive beam. The beamformer includes a delay generator corresponding to each transducer element for delaying the received signal. The delay generator includes a delay unit and a delay controller. The delay is variable in response to a change delay signal supplied by the delay controller at discrete times during reception of ultrasound energy. According to one feature of the invention, the delay represents an exact solution, within the quantization error of the delay unit, to the delay equation for the delay at a given steering angle, transducer element and focal depth. According to another feature of the invention, the delay controller generates a change delay signal that steers the receive beam to a dynamically variable steering angle and dynamically focuses the receive beam during reception of ultrasound energy.