A full directional hydrophone

Abstract

The application discloses a full-directional hydrophone, which comprises a hydrophone sensitive probe, a data acquisition module, a data storage module and a power management module, wherein the hydrophone sensitive probe comprises a spherical packaging shell, a ring-shaped PCB board, a front-stage signal processing circuit and a bidirectional micro-mechanical ultrasonic transducer; the bidirectional micro-mechanical ultrasonic transducer comprises a substrate, and the top surface and the bottom surface of the substrate are provided with symmetrically arranged insulating layers, lower electrode layers, device layers, vacuum cavities and upper electrode layers. The full-directional hydrophone has the advantages of scientific design, reasonable structure and good use effect, and achieves the purpose of having the same sensitivity to sound pressure signals within the 360-degree range of the plane where the hydrophone is located.

Description

Technical Field

[0001] This invention relates to the field of MEMS hydrophone technology, specifically an omnidirectional hydrophone. Background Technology

[0002] Hydrophones based on large-volume piezoelectric ceramics were first proposed as early as 1910, and since then, they have dominated the hydrophone market. Even now, the most advanced hydrophones on the market are manufactured using traditional, proprietary techniques on massive piezoelectric ceramics. However, piezoelectric ceramic-based hydrophones suffer from high cost and large size, hindering their development in various practical applications.

[0003] Hydrophones designed based on MEMS technology are characterized by their small size, low power consumption, and compatibility with CMOS standard manufacturing processes. In addition, hydrophones designed based on capacitive micromachined ultrasonic transducers (CMUTs) have attracted considerable attention due to their high performance, compact structure, and good compatibility with semiconductor mass production processes.

[0004] Directivity is an important indicator for measuring the sensitivity of a hydrophone to external sound pressure at different angles. Traditional hydrophones are only sensitive to sound pressure signals within a certain angular range, so it is particularly important to design a hydrophone that can achieve the same sensitivity to sound pressure signals across a 360-degree range in the plane in which the hydrophone is located. Summary of the Invention

[0005] The purpose of this invention is to solve the problems existing in the prior art and to provide an omnidirectional hydrophone based on CMUT.

[0006] This invention is achieved through the following technical solution:

[0007] An omnidirectional hydrophone includes a hydrophone sensitive probe, a data acquisition module, a data storage module, and a power management module; wherein, the output terminal of the hydrophone sensitive probe is connected to the input terminal of the data acquisition module, the output terminal of the data acquisition module is connected to the input terminal of the data storage module, and the power management module is connected to the hydrophone sensitive probe, the data acquisition module, and the data storage module respectively.

[0008] The hydrophone's sensitive probe comprises a spherical package, a ring-shaped PCB board, a pre-processing circuit, and a bidirectional micro-mechanical ultrasonic transducer. The ring-shaped PCB board is mounted in the center of the spherical package. The pre-processing circuit is integrated onto the ring-shaped PCB board. The bidirectional micro-mechanical ultrasonic transducer is mounted in a mounting slot in the center of the ring-shaped PCB board. The output of the bidirectional micro-mechanical ultrasonic transducer is connected to the input of the pre-processing circuit, and the output of the pre-processing circuit is connected to the input of the data acquisition module. The bidirectional micro-mechanical ultrasonic transducer and the ring-shaped PCB board are integrated to divide the spherical package cavity into an upper cavity and a lower cavity. Both the upper and lower cavities are filled with encapsulating adhesive for acoustic encapsulation.

[0009] Furthermore, the bidirectional micromechanical ultrasonic transducer includes a substrate. An upper insulating layer is disposed at the center of the top surface of the substrate. An annular upper lower electrode layer is disposed around the upper insulating layer. A groove is provided at the center of the surface of the upper insulating layer. An upper device layer is disposed on the upper insulating layer, enclosing the groove to form an upper vacuum cavity. An upper upper electrode layer is disposed on the upper device layer. A lower insulating layer is disposed at the center of the bottom surface of the substrate. An annular lower lower electrode layer is disposed around the lower insulating layer. A groove is provided at the center of the surface of the lower insulating layer. A lower device layer is disposed on the lower insulating layer, enclosing the groove to form a lower vacuum cavity. A lower upper electrode layer is disposed on the lower device layer. The upper insulating layer, upper lower electrode layer, upper device layer, upper vacuum cavity, and upper upper electrode layer are arranged symmetrically with respect to the substrate.

[0010] Furthermore, the upper vacuum cavity and the lower vacuum cavity are circular, square, or regular hexagonal cavities.

[0011] Furthermore, the bidirectional micromechanical ultrasonic transducer employs either a capacitive transducer or a piezoelectric transducer.

[0012] Furthermore, the pre-amplifier circuit consists of a pre-amplifier circuit, a bandpass filter circuit, and a second-stage amplifier circuit connected in sequence.

[0013] Furthermore, the encapsulating adhesive uses a material that matches the acoustic impedance of the water.

[0014] Furthermore, the encapsulating adhesive is made of polyethylene, polyurethane, or silicone.

[0015] This invention presents an omnidirectional hydrophone with a scientifically designed and rationally structured architecture, resulting in excellent performance. It achieves the goal of maintaining uniform sensitivity to sound pressure signals across a 360-degree range within the hydrophone's plane. Utilizing MEMS technology, this omnidirectional hydrophone integrates the sensitive detection component with the signal processing circuitry. All of these components can be implemented on a chip-scale, integrating the sensor, signal processing circuitry, and actuator onto a single substrate. This results in a small size, simple structure, high sensitivity, and adjustable sensitivity. The simple structure facilitates manufacturing and operation, while the high sensitivity provides sonar detection capabilities. Attached Figure Description

[0016] The accompanying drawings, which are provided to further illustrate the invention and form part of this application, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention.

[0017] Figure 1 This is a block diagram showing the connection of the various components in the omnidirectional hydrophone of the present invention.

[0018] Figure 2 This is a schematic diagram of the structure of the hydrophone sensitive probe in the omnidirectional hydrophone of the present invention.

[0019] Figure 3 This is a front view of the bidirectional micromechanical ultrasonic transducer in the sensitive probe of a hydrophone.

[0020] Figure 4 This is a top view of the bidirectional micromechanical ultrasonic transducer in the sensitive probe of a hydrophone.

[0021] In the diagram: 1-Hydrophone sensitive probe, 2-Data acquisition module, 3-Data storage module, 4-Power management module, 5-Spherical package shell, 6-Ring PCB board, 7-Bidirectional micro-mechanical ultrasonic transducer, 8-Encapsulating adhesive, 9-Substrate, 10-Upper insulating layer, 11-Upper lower electrode layer, 12-Upper device layer, 13-Upper vacuum cavity, 14-Upper upper electrode layer, 15-Lower insulating layer, 16-Lower lower electrode layer, 17-Lower device layer, 18-Lower vacuum cavity, 19-Lower upper electrode layer. Implementation

[0022] To enable those skilled in the art to better understand the present invention, the present invention will be further described clearly and completely below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0023] In the description of this invention, it should be understood that the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0024] An omnidirectional hydrophone, such as Figure 1 As shown, the system includes a hydrophone sensor 1, a data acquisition module 2, a data storage module 3, and a power management module 4. The output of the hydrophone sensor 1 is connected to the input of the data acquisition module 2, and the output of the data acquisition module 2 is connected to the input of the data storage module. The power management module 4 is connected to the hydrophone sensor 1, the data acquisition module 2, and the data storage module 3. The hydrophone sensor 1 converts underwater acoustic signals into analog voltage signals. The data acquisition module 2 transmits the acquired underwater acoustic signals to a host computer for calculation and display. The data storage module 3 stores the processed underwater acoustic signals or transmits them via a wired or wireless interface. The power management module 4 supplies power to the entire hydrophone system.

[0025] like Figure 2 As shown, the hydrophone sensitive probe 1 includes a spherical encapsulation shell 5, a ring-shaped PCB board 6, a pre-amplifier signal processing circuit, and a bidirectional micro-mechanical ultrasonic transducer 7. The ring-shaped PCB board 6 is installed in the middle of the spherical encapsulation shell 5. The pre-amplifier signal processing circuit is integrated on the ring-shaped PCB board 6 and consists of a pre-amplifier circuit, a band-pass filter circuit, and a secondary amplifier circuit connected in sequence. The bidirectional micro-mechanical ultrasonic transducer 7 is installed in a mounting slot in the middle of the ring-shaped PCB board 6. The output terminal of the bidirectional micro-mechanical ultrasonic transducer 7 is connected to the input terminal of the pre-amplifier signal processing circuit, and the output terminal of the pre-amplifier signal processing circuit is connected to the input terminal of the data acquisition module 2. The bidirectional micro-mechanical ultrasonic transducer 7 and the ring-shaped PCB board 6 are integrated to divide the cavity of the spherical encapsulation shell 5 into an upper cavity and a lower cavity. Both the upper and lower cavities are filled with encapsulating adhesive 8 for acoustic encapsulation. The encapsulating adhesive 8 uses a material that matches the acoustic impedance of water, such as polyethylene, polyurethane, or silicone. The encapsulating adhesive 8 completely isolates the bidirectional micro-mechanical ultrasonic transducer 7 from the underwater environment and enhances the received sound pressure signal.

[0026] like Figure 3 and Figure 4As shown, the bidirectional micromechanical ultrasonic transducer 7 includes a circular substrate 9. A circular upper insulating layer 10 is disposed at the center of the top surface of the substrate 9. A circular upper lower electrode layer 11 is disposed around the upper insulating layer 10. A groove is provided at the center of the surface of the upper insulating layer 10. A circular upper device layer 12 is disposed on the upper insulating layer 10, and the groove is closed to form an upper vacuum cavity 13. A circular upper upper electrode layer 14 is disposed on the upper device layer 12. A circular lower insulating layer 15 is disposed at the center of the bottom surface of the substrate 9. A circular lower electrode layer 16 is disposed around the lower insulating layer 15. A groove is provided at the center of the surface of the lower insulating layer 15. A circular lower device layer 17 is provided on the lower insulating layer 15, which closes the groove to form a lower vacuum cavity 18. A circular lower upper electrode layer 19 is provided on the lower device layer 17. The upper insulating layer 10, upper lower electrode layer 11, upper device layer 12, upper vacuum cavity 13, and upper upper electrode layer 14 are arranged symmetrically with the lower insulating layer 15, lower lower electrode layer 16, lower device layer 17, lower vacuum cavity 18, and lower upper electrode layer 19 on the substrate 9. The upper vacuum cavity 13 and lower vacuum cavity 18 can be circular, square, or hexagonal. The bidirectional micromechanical ultrasonic transducer 7 adopts a capacitive transducer or a piezoelectric transducer.

[0027] This invention relates to an omnidirectional hydrophone, a transducer that converts underwater acoustic signals into electrical signals. It is used to receive underwater acoustic signals and is widely applied in underwater communication, detection, identification, marine environmental monitoring, and the development and utilization of marine resources. This omnidirectional hydrophone amplifies the signal and converts it into a voltage output. It features small size, simple structure, high sensitivity, and adjustable sensitivity. Its simple structure facilitates manufacturing and operation, while its high sensitivity provides sonar detection capabilities.

[0028] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. An omnidirectional hydrophone, characterized in that: It includes a hydrophone sensitive probe, a data acquisition module, a data storage module, and a power management module; wherein, the output terminal of the hydrophone sensitive probe is connected to the input terminal of the data acquisition module, the output terminal of the data acquisition module is connected to the input terminal of the data storage module, and the power management module is connected to the hydrophone sensitive probe, the data acquisition module, and the data storage module respectively. The hydrophone's sensitive probe comprises a spherical package, a ring-shaped PCB board, a pre-processing circuit, and a bidirectional micro-mechanical ultrasonic transducer. The ring-shaped PCB board is mounted in the center of the spherical package. The pre-processing circuit is integrated on the ring-shaped PCB board. The bidirectional micro-mechanical ultrasonic transducer is mounted in a mounting slot in the center of the ring-shaped PCB board. The output of the bidirectional micro-mechanical ultrasonic transducer is connected to the input of the pre-processing circuit, and the output of the pre-processing circuit is connected to the input of the data acquisition module. The bidirectional micro-mechanical ultrasonic transducer and the ring-shaped PCB board are integrated to divide the cavity of the spherical package into an upper cavity and a lower cavity, both filled with encapsulating adhesive. A bidirectional micromechanical ultrasonic transducer includes a substrate. An upper insulating layer is located at the center of the top surface of the substrate. An annular upper lower electrode layer surrounds the upper insulating layer. A groove is located at the center of the surface of the upper insulating layer. An upper device layer is located on the upper insulating layer, enclosing the groove to form an upper vacuum cavity. An upper upper electrode layer is located on the upper device layer. A lower insulating layer is located at the center of the bottom surface of the substrate. An annular lower lower electrode layer surrounds the lower insulating layer. A groove is located at the center of the surface of the lower insulating layer. A lower device layer is located on the lower insulating layer, enclosing the groove to form a lower vacuum cavity. A lower upper electrode layer is located on the lower device layer. The upper insulating layer, upper lower electrode layer, upper device layer, upper vacuum cavity, and upper upper electrode layer are arranged symmetrically with respect to the substrate.

2. The omnidirectional hydrophone according to claim 1, characterized in that: The upper and lower vacuum cavities are circular, square, or hexagonal.

3. The omnidirectional hydrophone according to claim 2, characterized in that: The bidirectional micromechanical ultrasonic transducer uses either a capacitive transducer or a piezoelectric transducer.

4. An omnidirectional hydrophone according to any one of claims 1-3, characterized in that: The preamplifier circuit consists of a preamplifier circuit, a bandpass filter circuit, and a secondary amplifier circuit connected in sequence.

5. An omnidirectional hydrophone according to claim 4, characterized in that: The encapsulating adhesive uses a material that matches the acoustic impedance of the water.

6. An omnidirectional hydrophone according to claim 5, characterized in that: The encapsulating adhesive is made of polyethylene, polyurethane, or silicone.

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