Delay interpolator for digital phased array ultrasound beamformers

摘要

A delay interpolator for use in each channel of a digital ultrasound beamformer includes an FIR digital filter that is responsive to delay control information for delaying digital samples of the received beam by different delays that are quantized in increments less than the sampling period and a control unit for supplying the delay control information to the FIR digital filter. In a preferred embodiment, all but one of the filter coefficients are of the form 1/2.sup.m, where m is an integer, and multiplication is implemented in the FIR digital filter by shifting bits of the data samples by m bit positions. The FIR digital filter preferably includes a gain correction multiplier for correcting the gain of the delayed digital samples. The FIR digital filter delay interpolator can utilize a pipeline structure for high speed operation. In addition, the FIR digital filter delay interpolator can be used in a time multiplexed beamformer to process several beams simultaneously.