MUT circuit with an electrically controllable membrane

Patent metadata

Field	Value
Publication number	US-9333535-B2
Application number	US-201213356993-A
Country	US
Kind code	B2
Filing date	Jan 24, 2012
Priority date	Jan 24, 2012
Publication date	May 10, 2016
Grant date	May 10, 2016

Abstract

A micromachined ultrasonic transducer (MUT) circuit, which has a MUT with a MUT membrane that can vibrate back and forth to transmit an ultrasonic wave, electrically controls the movement of the MUT membrane by controllably transferring energy to the MUT membrane, thereby allowing the MUT membrane to transmit substantially any desired ultrasonic wave.

First claim

What is claimed is:

1. A micromachined ultrasonic transducer (MUT) circuit comprising:
a membrane; and
a transmit circuit connected to the membrane, the transmit circuit configured to output a transmit signal to the membrane to transfer energy to the membrane, the transmit signal having an initial waveform that transfers an initial amount of energy that causes the membrane to first move in a first direction to a first position, and then move in a second direction opposite the first direction from the first position to a second position, the transmit signal having, after the initial waveform, an additional waveform that transfers an additional amount of energy to the membrane, the initial and additional amounts of energy being different, and the transmit signal having, after the additional waveform, a cancellation waveform that transfers a cancellation amount of energy to the membrane, wherein said initial waveform and said additional waveform and said cancellation waveform are voltage waveforms that each begins at a common reference voltage level, and then moves from said common reference voltage level to a another voltage level, and then returns to end at said common reference voltage level.

2. The MUT circuit of claim 1 wherein: the membrane moves in the first direction a number of times after receiving the initial amount of energy; and the additional amount of energy is transferred to the membrane before the membrane has moved the number of times in the first direction.

3. The MUT circuit of claim 1 wherein the additional amount of energy is less than the initial amount of energy.

4. The MUT circuit of claim 1 wherein the additional amount of energy is transferred to the membrane while the membrane is moving in the first direction.

5. The MUT circuit of claim 1 wherein the membrane moves in the first direction from the second position to substantially the first position in response to the additional amount of energy.

6. The MUT circuit of claim 1 wherein an additional amount of energy and the cancellation amount of energy are different.

7. The MUT circuit of claim 1 wherein the cancellation amount of energy is greater than the additional amount of energy.

8. The MUT circuit of claim 1 wherein the cancellation waveform transfers the cancellation amount of energy when the membrane moves in the second direction.

9. The MUT circuit of claim 1 wherein the cancellation amount of energy substantially stops a movement of the membrane.

10. The MUT circuit of claim 1 and further comprising a receive circuit electrically connected to receive an output signal that is generated by a movement of the membrane, and generate a digitized signal that represents the output signal.

11. The MUT circuit of claim 10 wherein the digitized signal corresponds with the transmit signal.

12. The MUT circuit of claim 10 and further comprising a processing circuit that is electrically connected to the transmit circuit and the receive circuit, the processing circuit to compare the digitized signal to a digitized golden signal.

13. The MUT circuit of claim 12 wherein the transmit circuit includes a memory, the processor to store a series of digital values in the memory that represent the transmit signal when the digitized signal matches the digitized golden signal within an error tolerance.

14. The MUT circuit of claim 12 wherein when the digitized signal fails to match the digitized golden signal within the error tolerance, the processor changes the series of digital values output by the processor to generate a different transmit signal, and continues generating different transmit signals until a digitized signal matches the digitized golden signal within the error tolerance.

15. The MUT circuit of claim 14 wherein the transmit circuit includes a memory, the processor to store a series of digital values in the memory that represent a matching transmit signal when a digitized signal matches the digitized golden signal within an error tolerance.

16. The MUT circuit of claim 14 wherein when the processor compares every digitized signal to the digitized golden signal.

17. A method of transducing comprising:
transferring an initial amount of energy with an electrical signal to a membrane of a micromachined ultrasonic transducer to cause the membrane to move initially in a first direction to a first position, and then move in a second direction opposite the first direction from the first position to a second position;
transferring an additional amount of energy to the membrane with the electrical signal after said transferring the initial amount of energy, the initial and additional amounts of energy being different, and
transferring a cancellation amount of energy to the membrane with the electrical signal after said transferring the additional amount of energy;
wherein said initial amount of energy and said additional amount of energy and said cancellation amount of energy are transferred by respectively associated voltage waveforms of the electrical signal that each begins at a common reference voltage level, and then moves from said common reference voltage level to a another voltage level, and then returns to end at said common reference voltage level.

18. The method of claim 17 wherein: the membrane moves in the first direction a number of times after receiving the initial amount of energy; and the additional amount of energy is transferred to the membrane before the membrane has moved the number of times in the first direction.

19. The method of claim 17 wherein the additional amount of energy is less than the initial amount of energy.

20. A transducing system, comprising:
means for transferring an initial amount of energy with an electrical signal to a membrane of a micromachined ultrasonic transducer to cause the membrane to move initially in a first direction to a first position, and then move in a second direction opposite the first direction from the first position to a second position;
means for transferring an additional amount of energy to the membrane with the electrical signal after said transferring the initial amount of energy, the initial and additional amounts of energy being different, and
means for transferring a cancellation amount of energy to the membrane with the electrical signal after said transferring the additional amount of energy;
wherein said initial amount of energy and said additional amount of energy and said cancellation amount of energy are transferred by respectively associated voltage waveforms of the electrical signal that each begins at a common reference voltage level, and then moves from said common reference voltage level to a another voltage level, and then returns to end at said common reference voltage level.

Assignees

• Barkin David Brian
• Posamentier Joshua
• Wygant Ira Oaktree
• Texas Instruments Inc

Inventors

• Barkin David Brian
• Posamentier Joshua
• Wygant Ira Oaktree

Classifications

• B06B2201/30

  with electronic damping · CPC title

• B06B1/0207 Primary

  Driving circuits (specially adapted for particular applications, see the relevant subclass, e.g. G01; circuits for steering transducer arrays G10K11/34; basic circuits H03) · CPC title

• B06B2201/51

  Electrostatic transducer · CPC title

• B06B2201/55

  Piezoelectric transducer · CPC title