Dual-mode operation micromachined ultrasonic transducer
First Claim
1. A method for operating a capacitive micromachined ultrasonic transducer (cMUT), the method comprising:
- providing the cMUT including a spring member for enabling a first electrode and a second electrode to move toward and away from each other, the cMUT having a contact point which does not connect the spring member with an opposing surface facing the spring member in a first operating condition of the cMUT, and connects the spring member with the opposing surface facing the spring member in a second operating condition, so that the cMUT has a first frequency response in the first operating condition and a second frequency response in the second operating condition, wherein;
the first frequency response and the second frequency response are substantially different from each other; and
a position of the contact point is controlled so that the first frequency response has a center frequency around a fundamental frequency of the cMUT, and the second frequency response has a center frequency around a harmonic frequency of the cMUT;
configuring the cMUT so that the cMUT operates in a first operation mode when the cMUT is in the first operating condition, and operates in a second operation mode when the cMUT is in the second operating condition; and
switching the cMUT between the first operating condition and the second operating condition.
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Accused Products
Abstract
Implementations of a cMUT have dual operation modes. The cMUT has two different switchable operating conditions depending on whether a spring member in the cMUT contacts an opposing surface at a contact point in the cMUT. The two different operating conditions have different frequency responses due to the contact. The cMUT can be configured to operate in transmission mode when the cMUT in the first operating condition and to operate in reception mode when the cMUT is in the second operating condition. The implementations of the dual operation mode cMUT are particularly suitable for ultrasonic harmonic imaging in which the reception mode receives higher harmonic frequencies.
89 Citations
24 Claims
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1. A method for operating a capacitive micromachined ultrasonic transducer (cMUT), the method comprising:
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providing the cMUT including a spring member for enabling a first electrode and a second electrode to move toward and away from each other, the cMUT having a contact point which does not connect the spring member with an opposing surface facing the spring member in a first operating condition of the cMUT, and connects the spring member with the opposing surface facing the spring member in a second operating condition, so that the cMUT has a first frequency response in the first operating condition and a second frequency response in the second operating condition, wherein; the first frequency response and the second frequency response are substantially different from each other; and a position of the contact point is controlled so that the first frequency response has a center frequency around a fundamental frequency of the cMUT, and the second frequency response has a center frequency around a harmonic frequency of the cMUT; configuring the cMUT so that the cMUT operates in a first operation mode when the cMUT is in the first operating condition, and operates in a second operation mode when the cMUT is in the second operating condition; and switching the cMUT between the first operating condition and the second operating condition. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for operating a capacitive micromachined ultrasonic transducer (cMUT), the method comprising:
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providing a cMUT including a spring member for enabling a first electrode and a second electrode to move toward and away from each other, the cMUT having a contact point which does not connect the spring member with an opposing surface facing the spring member in a first operating condition of the cMUT, and connects the spring member with the opposing surface facing the spring member in a second operating condition, so that the cMUT has a first frequency response in the first operating condition and a second frequency response in the second operating condition, wherein; the first frequency response is characterized by a first frequency band; the second frequency response is characterized by a second frequency band substantially shifted toward a higher frequency relative to the first frequency band; and a position of the contact point is controlled so that the first frequency response has a center frequency around a fundamental frequency of the cMUT, and the second frequency response has a center frequency around a harmonic frequency of the cMUT; configuring the cMUT so that the cMUT operates in a transmission mode when the cMUT is in the first operating condition, and operates in a reception mode when the cMUT is in the second operating condition; and switching the cMUT between the first operating condition and the second operating condition. - View Dependent Claims (13)
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14. A capacitive micromachined ultrasonic transducer (cMUT) comprising:
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a first electrode; a second electrode separated from the first electrode by an electrode gap so that a capacitance exists between the first electrode and the second electrode; a spring member supporting the second electrode for enabling the first electrode and the second electrode to move toward or away from each other; a contact structure disposed on the spring member or opposing surface facing the spring member, the contact structure not connecting the spring member with an opposing surface in a first operating condition of the cMUT, and connecting the spring member with the opposing surface in a second operating condition of the cMUT, so that the cMUT has a first frequency response in the first operating condition and a second frequency response in the second operating condition, wherein; the first frequency response and the second frequency response are substantially different from each other; and a position of the contact structure is controlled so that the first frequency response has a center frequency around a fundamental frequency of the cMUT, and the second frequency response has a center frequency around a harmonic frequency of the cMUT; and a switch for switching the cMUT between the first operating condition and the second operating condition, the first operating condition corresponding to a first operation mode, and the second operating condition corresponding to a second operation mode. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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Specification