US 12,703,003 B2Granted

Pulse shaping methods for non-linear acoustic piezoelectric transducers

AssigneeEcole De Technologie Superieure

InventorsFrederic Nabki, Mathieu Gratuze

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Abstract

Piezoelectric Micromachined Ultrasonic Transducers (PMUTs) exploiting microelectromechanical systems (MEMS) support monolithic integration with silicon based CMOS electronic thereby leveraging the cost benefits of large wafer automated silicon processing. However, nonlinear behaviour in MEMS resonators compromises their performance in some applications whilst being desired in other applications. Accordingly, the inventors have established techniques for the characterisation of the nonlinear behaviour allowing designers to tailor the design and manufacturing of the MEMS resonators to particular applications. Further, there are provided drive schemes for these MEMS resonators for improved performance with respect to the generation of pulses from such MEMS resonators.

Claims13

Dependent claims

A method of driving a non-linear acoustic resonator comprising:

providing a control circuit for controlling the non-linear resonator wherein the control circuit generates an excitation signal in dependence upon a target output from the non-linear resonator and established characteristics of the non-linear resonator;
and
applying the excitation signal to the non-linear resonator;
wherein
the excitation signal comprises:
an initial segment of a predetermined duration where the excitation signal sweeps from a first predetermined frequency to a second predetermined frequency over the length of the initial segment according to a first frequency function and from a first predetermined amplitude to a second predetermined amplitude over the length of the initial segment according to a first amplitude function;
a subsequent segment immediately following the initial segment having another predetermined duration where the frequency of the excitation signal is kept constant at a third predetermined frequency and varies from a third predetermined amplitude at the beginning of the subsequent segment to a fourth predetermined amplitude at the end of the subsequent segment according to a second amplitude function;
wherein
the first frequency function defines the frequency of the excitation signal applied as a function of time through the initial segment;
the first amplitude function defines the amplitude of the excitation signal applied as a function of time through the initial segment;
the second amplitude function defines the amplitude of the excitation signal applied as a function of time through the subsequent segment;
and
the first predetermined frequency, the second predetermined frequency and the third predetermined frequency are established in dependence upon whether the non-linear resonator is a hardening type resonator or a softening type resonator.

10 more elements

A method of driving a non-linear acoustic resonator comprising:

providing a control circuit for controlling the non-linear resonator wherein the control circuit generates an excitation signal in dependence upon a target output from the non-linear resonator and established characteristics of the non-linear resonator;
and
applying the excitation signal to the non-linear resonator;
wherein
the excitation signal comprises:
an initial segment of a predetermined duration and a predetermined amplitude where a frequency of the excitation signal sweeps from a first predetermined frequency to a second predetermined frequency over the initial segment;
a subsequent segment immediately following the initial segment having another predetermined duration and another predetermined amplitude where the frequency of the excitation signal is sweeps from the second predetermined frequency to a third predetermined frequency over the subsequent segment;
a further segment immediately following the subsequent segment having a further predetermined duration and a further predetermined amplitude where the frequency of the excitation signal is kept constant at the third predetermined frequency;
and
another segment immediately following the further segment having yet another predetermined duration and yet another predetermined amplitude where the frequency of the excitation signal is sweeps from the third predetermined frequency to a fourth predetermined frequency over the subsequent segment;
and
the first predetermined frequency, the second predetermined frequency, the third predetermined frequency, and the fourth predetermined frequency are established in dependence upon whether the non-linear resonator is a hardening type resonator or a softening type resonator.

9 more elements

A method of driving a non-linear acoustic resonator comprising:

providing a control circuit for controlling the non-linear resonator wherein the control circuit generates an excitation signal in dependence upon a target output from the non-linear resonator and established characteristics of the non-linear resonator;
and
applying the excitation signal to the non-linear resonator;
wherein
the excitation signal comprises:
an initial segment of an initial predetermined duration where the excitation signal sweeps from a first predetermined frequency and first predetermined amplitude to a second predetermined frequency and second predetermined amplitude over the initial segment;
a subsequent segment of a subsequent predetermined duration where the excitation signal sweeps from a third predetermined frequency and third predetermined amplitude to a fourth predetermined frequency and fourth predetermined amplitude over the subsequent segment;
a further segment of a further predetermined duration where the excitation signal sweeps from a fifth predetermined frequency and fifth predetermined amplitude to a sixth predetermined frequency and sixth predetermined amplitude over the further segment;
another segment of another predetermined duration where the excitation signal sweeps from a seventh predetermined frequency and seventh predetermined amplitude to an eighth predetermined frequency and an eighth predetermined amplitude over the another segment;
the first predetermined frequency, the second predetermined frequency, the third predetermined frequency, the fourth predetermined frequency, the fifth predetermined frequency, the sixth predetermined frequency, the seventh predetermined frequency and the eighth predetermined frequency are established in dependence upon whether the non-linear resonator is a hardening type resonator or a softening type resonator.

7 more elements

A method of driving a non-linear acoustic resonator comprising:

providing a control circuit for controlling the non-linear resonator wherein the control circuit generates an excitation signal in dependence upon a target output from the non-linear resonator and established characteristics of the non-linear resonator;
and
applying the excitation signal to the non-linear resonator;
wherein
the excitation signal comprises:
an initial segment of an initial predetermined duration where the excitation signal sweeps from a first predetermined frequency to a second predetermined frequency over the length of the initial segment according to a first frequency function and from a first predetermined amplitude to a second predetermined amplitude over length of the initial segment according to a first amplitude function;
a subsequent segment of a subsequent predetermined duration where the excitation signal sweeps from a third predetermined frequency to a fourth predetermined frequency over the length of the subsequent segment according to a second frequency function and from a third predetermined amplitude to a fourth predetermined amplitude over the length of the subsequent segment according to a second amplitude function;
a further segment of a further predetermined duration where the excitation signal sweeps from a fifth predetermined frequency to a sixth predetermined frequency over the length of the further segment according to a third frequency function and from fifth predetermined amplitude to a sixth predetermined amplitude over the length of further segment according to a third amplitude function;
and
another segment of another predetermined duration where the excitation signal sweeps from a seventh predetermined frequency to an eighth predetermined frequency over the length of the another segment according to a fourth frequency function and from a seventh predetermined amplitude to an eighth predetermined amplitude over the length another segment according to a fourth amplitude function;
and
the first predetermined frequency, the second predetermined frequency, the third predetermined frequency, the fourth predetermined frequency, the fifth predetermined frequency, the sixth predetermined frequency, the seventh predetermined frequency and the eighth predetermined frequency are established in dependence upon whether the non-linear resonator is a hardening type resonator or a softening type resonator.

9 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/699,392Filed 14 Oct 2022 · us provisional application
Priority: 14 Oct 2021
Published: US 2024/0416384 A119 Dec 2024
Granted: 11 Aug 2026
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

B06B 1/0215
Driving circuits: for generating pulses, e.g. bursts of oscillations, envelopes
G10K 9/122
Electrically operated: using piezoelectric driving means
B06B 1/0644
Operating with piezoelectric effect or with electrostriction: using a single piezoelectric element
B06B 2201/55
Application to a particular transducer type: piezoelectric transducer