Abstract: An apparatus includes a transducer array with a plurality of CMUT elements. Each of the plurality of CMUT elements includes a first end and a second end. The transducer array further includes a bias network that is electrically connected with the first and second ends of the plurality of CMUT elements. The bias network applies a first bias voltage to the first end of the plurality of CMUT elements and a second bias voltage to the second end of the plurality of CMUT elements. The first and second bias voltages bias the plurality of CMUT elements. A method includes biasing, with bias network, a CMUT element of an transducer array using a bipolar signal that includes a first bias voltage and a second bias voltage, transmitting, by a transmit circuit, a transmit signal to the CMUT element, receiving, by a receive circuit, a receive signal from the CMUT element.

Abstract: An apparatus (402) includes an analog beamformer (414) that receives a set of analog RF signals. The set of analog RF signals are generated by a corresponding set of transducer elements (406) receiving ultrasound echo signals. The analog beamformer includes a delay network (416) with a set of phase shifting networks (506). Each phase shifting network of the set of phase shifting networks processes a different one of the analog RF signals of the set of analog RF signals. Each phase shifting network of the set of phase shifting networks adds a delay to the corresponding analog RF signal, producing a set of delayed analog RF signals that are aligned in time. The set of phase shifting networks does not use an inductive element to determine or add the delays. The analog beamformer further includes a summer (504) that sums the delayed analog RF signals, producing an analog beam sum.

Abstract: An ultrasound imaging method includes identifying a two-level pulse coding scheme (519), which includes a positive voltage value and a negative voltage value, for harmonic imaging. The method further includes driving a pulse generator (510) with the two-level pulse coding scheme. The method further includes producing, with the pulse generator, an excitation pulse. The method further includes routing the excitation pulse through a switch (518) to an ultrasonic transducer array (504), which transmits a first ultrasound signal in response thereto. The method further includes receiving first echoes generated in response to the excitation pulse. The method further includes processing the first echoes to extract a harmonic signal. The method further includes beamforming the harmonic signal to produce an image.

Abstract: An apparatus includes a transducer array with a plurality of CMUT elements. Each of the plurality of CMUT elements includes a first end and a second end. The transducer array further includes a bias network that is electrically connected with the first and second ends of the plurality of CMUT elements. The bias network applies a first bias voltage to the first end of the plurality of CMUT elements and a second bias voltage to the second end of the plurality of CMUT elements. The first and second bias voltages bias the plurality of CMUT elements. A method includes biasing, with bias network, a CMUT element of an transducer array using a bipolar signal that includes a first bias voltage and a second bias voltage, transmitting, by a transmit circuit, a transmit signal to the CMUT element, receiving, by a receive circuit, a receive signal from the CMUT element.

Abstract: An apparatus (402) includes an analog beamformer (414) that receives a set of analog RF signals. The set of analog RF signals are generated by a corresponding set of transducer elements (406) receiving ultrasound echo signals. The analog beamformer includes a delay network (416) with a set of phase shifting networks (506). Each phase shifting network of the set of phase shifting networks processes a different one of the analog RF signals of the set of analog RF signals. Each phase shifting network of the set of phase shifting networks adds a delay to the corresponding analog RF signal, producing a set of delayed analog RF signals that are aligned in time. The set of phase shifting networks does not use an inductive element to determine or add the delays. The analog beamformer further includes a summer (504) that sums the delayed analog RF signals, producing an analog beam sum.