US Patent 10251624 Delta-sigma beamformer and method for beamforming

A delta-sigma beamformer includes a beamsummer and a plurality of delta-sigma modules. Each of the delta sigma modules includes a delta-sigma modulator configured to receive analog ultrasound signals from one or more transducer elements and output a delay line including a plurality of samples based on the analog ultrasound signals. Each delta-sigma modulator includes a comb filter connected to the delta-sigma modulator and configured to output a difference between two of the plurality of samples in the delay line. Each delta-sigma modulator includes an accumulator module. Each accumulator module includes an accumulator connected to the comb filter. Each accumulator module is configured to integrate signals received from the comb filter during a non-delay-expansion period and transmit the integrated signals to the beamsummer during the non-delay-expansion period. Each accumulator module is configured to output a zero to the beamsummer during a delay-expansion period.