Ultrasound probe with digital microbeamformer using fir filters with no multipliers

An ultrasound probe for digital microbeamforming, comprising:

• an array of transducer elements configured to generate analog echo signals;
• a digital microbeamformer comprising:
• a digital integrated circuit coupled to an analog integrated circuit and comprising:
• a plurality of low power analog to digital converters (ADCs) configured to convert a plurality of partially-beamformed analog echo signals from the analog integrated circuit to a plurality of digital echo signal samples;
• and
• digital beamforming circuitry that is coupled to the plurality of low power ADCs and configured to receive the plurality of digital echo signal samples,
• wherein the digital beamforming circuitry comprises a digital delay circuit,
• wherein the digital delay circuit comprises a finite impulse response (FIR) filter,
• wherein the FIR filter comprises:
• a first shift and add weighting circuit comprising:
• an input configured to receive a digital echo signal sample of the plurality of digital echo signal samples;
• and
• an output configured to provide a first weighted and delayed digital echo signal sample generated from the digital echo signal sample without the use of multipliers;
• and
• a multiplexer comprising:
• a first input configured to receive the first weighted and delayed digital echo signal sample such that the output of the first shift and add weighting circuit is coupled only to the first input;
• a second input configured to receive the digital echo signal sample;
• and
• an output configured to provide the digital echo signal sample or the first weighted and delayed digital echo signal sample.