Ultrasound signal processor

摘要

In an ultrasound signal processor, respective received signals received at received signal processing units are sampled by a sampling clock of a frequency which is sufficiently higher than a Nyquist sampling frequency of an upper limit of a frequency band width for each of the received signals received at the received signal processing units so as to be digitized. Each of the digitized received signals is multiplied by a reference signal of a predetermined frequency to produce converted received signals in which the frequency of the digital received signal waveform is shifted, and converted signals are cumulated for a time which is longer than the sampling period. Each of the cumulated signals is processed by a clock frequency lower than the sampling clock in connection with an ultrasound beam in one direction, so that after one transmission operation of ultrasound, a plurality of ultrasound received beams are formed from the received signals received at the respective transducers.