Method and apparatus for transmit beamformer

A method for producing an ultrasonic waveform, comprising the steps of:

• providing to a signal path waveform samples for said ultrasonic waveform;
• and
• applying to an ultrasonic transducer an output waveform responsive to said initial waveform samples, said method further comprising, prior to said step of applying, at least one of:
• the step of modulating by a desired frequency samples in said signal path,
• the step of upsampling samples in said signal path,
• the step of interpolating samples in said signal path,
• the step of time delaying by a time delay samples in said signal path,
• the step of focus filtering by a filter samples in said signal path, and
• the step of phase rotating by a phase samples in said signal path.

An ultrasonic transmit beamformer apparatus for use with a plurality of ultrasonic transducers arranged in an array, comprising:

• a source of quantized initial waveform samples of at least two bits;
• output waveforms responsive to said source of samples, said output waveforms to be applied to each of said transducers to produce an ultrasonic beam;
• a respective signal path coupled between said source and each of said transducers;
• means for time delaying in said signal path to apply a time-delay component according to a delay profile across the array, to which each output waveform is responsive in forming said beam.

A method for transmitting an ultrasonic beam from a plurality of ultrasonic transducers arranged in an array, comprising the steps of:

• providing quantized initial waveform samples of at least two bits in a signal path for output waveforms to be applied to each of said transducers to produce said ultrasonic beam;
• time delaying in said signal path according to a time-delay component of a delay profile across the array for said beam;
• and
• adjusting phase in said signal path according to a phase component of said delay profile across the array for said beam.

Art ultrasonic transmit apparatus comprising:

• a source of initial waveform samples;
• an ultrasonic transducer;
• and
• a signal path coupled between said source and said transducer,
• wherein said signal path comprises a digital signal path coupled to a digital-to-analog converter (DAC) coupled to an analog signal path, at least a portion of said source of initial waveform samples and said digital signal path, and at least a portion of said DAC, being combined on an integrated circuit.

Art ultrasonic transmit apparatus comprising:

• a source of initial waveform samples;
• an ultrasonic transducer;
• and
• a signal path coupled between said source and said transducer,
• wherein said signal path comprises a digital signal path coupled to a DAC coupled to an analog signal path,
• and wherein said DAC has a differential output.

A method for producing an ultrasonic transmit beam, in a system including a plurality of ultrasonic transducers arranged in an array, said system further including a transmitter for each of said transducers, each of said transmitters including a source of initial waveform samples and a signal path coupled between the source of initial waveform samples for the transmitter and the transducer for the transmitter, comprising the steps of:

• obtaining for each of said transmitters, an error value for a first parameter which the transmitter uses in its signal path;
• downloading to each of said transmitters, a calibration value responsive to the error value obtained for the respective transmitter;
• and
• causing each of said transmitters to provide to its transducer a respective output waveform which is responsive to the calibration value downloaded to the respective transmitter.

A method for producing an ultrasonic transmit beam, in a system including a plurality of ultrasonic transducers arranged in an array, said system further including a transmitter for each of said transducers, each of said transmitters including a source of initial waveform samples and a signal path coupled between the source of initial waveform samples for the transmitter and the transducer for the transmitter, said signal path including a digital signal path coupled to the source of initial waveform samples, a DAC coupled to the digital signal path, and an analog signal path coupled between the DAC and the transducer for the transmitter, comprising the steps of:

• obtaining, for each of said transmitters, a characterization of the frequency response of a member of the group consisting of the analog signal path of the transmitter, the transducer for the transmitter, and the analog signal path of the transmitter in combination with the transducer for the transmitter;
• downloading to the source of initial waveform samples for each of said transmitters, a respective set of initial waveform samples which are responsive to said characterization obtained for the transmitter;
• and
• causing each of said transmitters to provide to its transducer a respective output waveform which is responsive to the initial waveform samples downloaded to the respective transmitter.

An ultrasonic transmit beamformer comprising:

• a plurality of independent transmitters each having a source of waveform samples coupled to a signal processing path for processing a signal which is representative of at least one beam;
• and
• wherein each of said independent transmitters performs beamforming operations;
• and
• further wherein said independent transmitters are separate from a control that programs each transmitter with different programmable parameters.

Art ultrasonic transmit beamformer apparatus, comprising:

• a source of initial waveform samples for a first output signal;
• a digital signal processing path coupled to said source of initial waveform samples;
• a DAC coupled to said digital signal processing path;
• an output signal path coupled to said DAC;
• and
• an ultrasonic transducer coupled to said output signal path.

An ultrasonic transmit beamformer apparatus, comprising:

• a source of initial waveform samples for a first output waveform;
• a signal path coupled to said source of initial waveform samples;
• and
• an ultrasonic transducer coupled to said signal path,
• wherein said signal path includes at least two of the following:
• an upsampler, an interpolator, a modulator, a time delay element, a phase rotation element, a focusing filter, and an apodization weighting element.

An ultrasonic transmit beamformer apparatus, comprising:

• a source of initial waveform samples for a first output signal;
• a digital signal processing path coupled to said source of initial waveform samples;
• a DAC coupled to said digital signal processing path;
• an output signal path coupled to said DAC;
• and
• an ultrasonic transducer coupled to said output signal path,
• said apparatus further comprising a delay register receiving first and second delay values and a summer for summing said first and second delay values,
• wherein said digital signal processing path delays samples in said digital signal processing path by a time delay responsive to said delay value of said summer.

Art ultrasonic transmit beamformer apparatus, comprising:

• a source of initial waveform samples for a first output signal;
• a digital signal processing path coupled to said source of initial waveform samples;
• a DAC coupled to said digital signal processing path;
• an output signal path coupled to said DAC;
• and
• an ultrasonic transducer coupled to said output signal path,
• said apparatus further comprising a delay register receiving first and second delay values and a summer for summing said first and second delay values,
• wherein said digital signal processing path modifies the phase of samples in said digital signal processing path by a phase rotation amount responsive to a component of said delay value of said summer.

An ultrasonic transmit beamformer comprising:

• a plurality of independent transmitters each having a source of waveform samples coupled to a signal processing path for processing a signal which is representative of at least one beam;
• and
• wherein each of said independent transmitters performs beamforming operations;
• and
• further wherein each of said transmitters is independently responsive to a control that programs each transmitter with programmable parameters.

In an ultrasonic transmit beamformer having a signal path, the signal path comprising:

• a source of waveform samples;
• a digital-to-analog converter (DAC) coupled to said source of waveform samples;
• an ultrasonic transducer coupled to said DAC;
• and
• an upsampler to increase a sample rate associated with said waveform samples.

An ultrasonic transmit beamformer comprising:

• a plurality of transmitters;
• initial waveform samples in a waveform processing path per transmitter;
• and
• a control processor per transmitter to adjust the processing of said waveform processing path.