Ultra wide bandwidth piezoelectric transducer arrays

摘要

Piezoelectric micromachined ultrasonic transducer (pMUT) arrays and systems comprising pMUT arrays are described. In an embodiment, coupling strength within a population of transducer elements provides degenerate mode shapes that split for wide bandwidth total response while less coupling strength between adjacent element populations provides adequately low crosstalk between the element populations. In an embodiment, differing membrane sizes within a population of transducer elements provides differing frequency response for wide bandwidth total response while layout of the differing membrane sizes between adjacent element populations provides adequately low crosstalk between the element populations. In an embodiment, close packing of membranes within a population of transducer elements provides improved efficiency for the wide bandwidth embodiments. In an embodiment, elliptical piezoelectric membranes provide multiple resonant modes for wide bandwidth total response and high efficiency while orthogonality of the semi-principal axes between adjacent element populations provides adequately low crosstalk between the element populations.

主权项

1. A piezoelectric micromachined ultrasonic transducer (pMUT) array, comprising:
a plurality of drive/sense electrode rails disposed over an area of a substrate and electrically addressable independently; and a plurality of piezoelectric transducer element populations, wherein drive/sense electrodes within an element population are coupled to one of the drive/sense electrode rails, wherein electromechanical coupling between transducer elements of different transducer element populations is less than electromechanical coupling between transducer elements of a same element population, and wherein each transducer element population is to provide a plurality of separate but overlapping frequency responses; wherein the electromechanical coupling between transducer elements of a same element population is sufficient to induce at least one degenerate mode, the at least one degenerate mode having a degenerate resonant frequency split from a natural resonant frequency of an individual piezoelectric transducer element in the element population, wherein at least one of a distance, the elastic modulus of a material, or a cross-sectional coupling area of a first region between transducer elements of a same element population is different than a corresponding one of a second region between transducer elements of a different element populations, wherein two or more of the distance, the elastic modulus, or the cross-sectional coupling area are different between the first and second regions.