Methods for reducing ringing of ultrasonic transducers

• US 6,731,569 B2
• Filed: 07/30/2002
• Issued: 05/04/2004
• Est. Priority Date: 03/16/2001
• Status: Expired due to Fees

• Current Assignee: American Vehicular Sciences LLC (Acacia Research Corporation)
• Original Assignee: Automotive Technologies International Incorporated
• Inventors: Yurchenko, Oleksandr V., Johnson, Wendell C., DuVall, Wilbur E.
• Primary Examiner(s): Pihulic, Daniel T.
• Application Number:
  US10/208,522
• Publication Number:
  US 20030039173A1
• Time in Patent Office: 644 Days
• Field of Search: 367/903, 367/138, 367/135, 367/901
• US Class Current: 367/138
• CPC Class Codes: B06B 1/0215 for generating pulses, e.g. bursts of oscillations, envelopes
• CPC Class Codes: Y10S 367/903 Transmit-receive circuitry

Abstract

Methods for reducing ringing of dual-function ultrasonic air-coupled transducers in which at least one electrical passive circuit is applied to the transducer. The circuit may be either a linear circuit or a non-linear circuit. Different circuits can be applied to the transducer when the transducer is in a transmission mode than when the transducer is in a reception mode.

Claims

1. A method for reducing ringing of dual-function, air-coupled ultrasonic transducers, comprising the steps of:

applying at least one inductance in series and/or in parallel to the transducer electrical terminals to obtain a decreased dead zone of the transducer; and

applying at least one passive electrical circuit in series and/or parallel to the inductance; and

applying a different electrical passive circuit to the transducer when the transducer is in a transmission mode than when the transducer is in a reception mode.

2. The method of claim 1, wherein the at least one electrical passive circuit is a non-linear circuit.

3. The method of claim 1, wherein the at least one electrical passive circuit is a linear circuit.

4. The method of claim 3, further comprising the step of synthesizing the linear circuit using known input impedance/admittance of the transducer.

5. The method of claim 4, further comprising the step of optimizing the linear circuit on the basis of a broadband matching theory.

6. The method of claim 5, further comprising the step of optimizing the generator output impedance to obtain a predetermined ringing at a given input signal.

7. The method of claim 3, further comprising the step of constructing the linear circuit with a higher order transfer function and including at least one capacitor and at least one inductor.

8. An arrangement for reducing ringing of dual-function, air-coupled ultrasonic transducers, comprising:

a first electrical passive circuit adapted to be coupled to the transducer, said first circuit including at least one inductance adapted to be in series and/or in parallel to the transducer to obtain a decreased dead zone of the transducer;

a second electrical passive circuit adapted to be coupled to the transducer; and

switching means for switching between said first and second circuits such that one of said first and second circuits is coupled to the transducer when the transducer is in a transmission mode and the other of said first and second circuits is coupled to the transducer when the transducer is in a reception mode.

9. The arrangement of claim 8, wherein said first circuit further comprising switching means for modifying said first circuit such that a first construction of said first circuit is coupled to the transducer when the transducer is in a transmission mode and a second construction of said first circuit, different from said first construction, is coupled to the transducer when the transducer is in a reception mode.

10. The arrangement of claim 8, wherein said first circuit is a non-linear circuit.

11. The arrangement of claim 8, wherein said first circuit is a linear circuit.

12. The arrangement of claim 11, wherein said linear circuit is synthesized using known input impedance/admittance of the transducer.

13. The arrangement of claim 12, wherein said linear circuit is optimized on the basis of a broadband matching theory.

14. The arrangement of claim 13, wherein the generator output impedance is optimized to obtain a predetermined ringing at a given input signal.

15. The arrangement of claim 11, wherein said linear circuit is constructed with a higher order transfer function and includes at least one capacitor and at least one inductor.

16. A method for reducing ringing of dual-function ultrasonic, air-coupled transducers, comprising the steps of:

providing a plurality of electrical components at least one of which is capable of providing inductance;

coupling a switching device with the components to enable the construction of at least a first circuit and a second circuit depending on the status of the switching device;

selectively coupling the components to the transducer such that the inductance-providing component is in series and/or in parallel with the transducer; and

controlling the switching device in conjunction with the operation of the transducer such that the first circuit is coupled to the transducer during a transmission mode of the transducer and the second circuit is coupled to the transducer during the reception mode of the transducer to obtain a decreased dead zone of the transducer.

17. A method for reducing ringing of dual-function, air-coupled ultrasonic transducers, comprising the steps of:

applying at least one inductance in series and/or in parallel to the transducer electrical terminals to obtain a decreased dead zone of the transducer; and

applying at least one passive electrical circuit in series and/or parallel to the inductance, the at least one electrical passive circuit being a linear circuit; and

synthesizing the linear circuit using known input impedance/admittance of the transducer.

18. The method of claim 17, further comprising the step of optimizing the linear circuit on the basis of a broadband matching theory.

19. The method of claim 18, further comprising the step of optimizing the generator output impedance to obtain a predetermined ringing at a given input signal.

20. A method for reducing ringing of dual-function, air-coupled ultrasonic transducers, comprising the steps of:

applying at least one inductance in series and/or in parallel to the transducer electrical terminals to obtain a decreased dead zone of the transducer; and

applying at least one passive electrical circuit in series and/or parallel to the inductance, the at least one electrical passive circuit being a linear circuit; and

constructing the linear circuit with a higher order transfer function and including at least one capacitor and at least one inductor.

21. An arrangement for reducing ringing of dual-function, air-coupled ultrasonic transducers, comprising:

a first electrical passive circuit adapted to be coupled to the transducer, said first circuit including at least one inductance adapted to be in series and/or in parallel to the transducer to obtain a decreased dead zone of the transducer;

said first circuit further comprising switching means for modifying said first circuit such that a first construction of said first circuit is coupled to the transducer when the transducer is in a transmission mode and a second construction of said first circuit, different from said first construction, is coupled to the transducer when the transducer is in a reception mode.

22. An arrangement for reducing ringing of dual-function, air-coupled ultrasonic transducers, comprising:

a first electrical passive circuit adapted to be coupled to the transducer, said first circuit including at least one inductance adapted to be in series and/or in parallel to the transducer to obtain a decreased dead zone of the transducer, said first circuit being a linear circuit,

said linear circuit being synthesized using known input impedance/admittance of the transducer.

23. The arrangement of claim 22, wherein said linear circuit is optimized on the basis of a broadband matching theory.

24. The arrangement of claim 23, wherein the generator output impedance is optimized to obtain a predetermined ringing at a given input signal.

25. An arrangement for reducing ringing of dual-function, air-coupled ultrasonic transducers, comprising:

a first electrical passive circuit adapted to be coupled to the transducer, said first circuit including at least one inductance adapted to be in series and/or in parallel to the transducer to obtain a decreased dead zone of the transducer, said first circuit being a linear circuit,

said linear circuit being constructed with a higher order transfer function and includes at least one capacitor and at least one inductor.

26. A dampening circuit for reducing ringing of dual-function, air-coupled ultrasonic transducers having a ring down time and an echo time, comprising:

a resistor;

an inductor connected in series with said resistor; and

a switching device arranged to switch said resistor and said inductor into a circuit with the transducer during the ring down time and out of circuit with the transducer during the echo time.

27. A method for reducing ringing of dual-function ultrasonic, air-coupled transducers, comprising the steps of:

providing a plurality of electrical components having variable characteristics, the electrical components including an inductor and a resistor;

coupling the components to the transducer such that the inductor and resistor are in series and/or in parallel with the transducer; and

controlling the characteristics of the electrical components in conjunction with the operation of the transducer such that a first circuit having specific characteristics is coupled to the transducer during a transmission mode of the transducer and a second circuit having different characteristics than the first circuit is coupled to the transducer during the reception mode of the transducer to obtain a decreased dead zone of the transducer.