Acoustic wave differential signal enhancement method and related system

Abstract

The invention relates to the technical field of sound wave signal detection and processing, and discloses a sound wave differential signal enhancement method and a related system, which utilize a pair of piezoelectric elements with opposite polarization directions to synchronously receive the same sound wave signal, and directly and naturally generate a pair of electric signals with opposite phases at a receiving end based on the physical principle of piezoelectric effect. The pair of signals form an ideal differential pair, and effective multiplication of signal amplitude and remarkable suppression of environment common-mode noise can be realized through subsequent simple subtraction operation due to the essential characteristics of the pair of signals. The method provides a brand-new and fundamental technical path for improving the signal-to-noise ratio and the anti-interference capability of the sound wave system.

Description

Technical Field

[0001] This invention belongs to the field of acoustic signal detection and processing technology, specifically an acoustic differential signal enhancement method and related system. Background Technology

[0002] Currently, most acoustic wave receiving systems rely on a single piezoelectric transducer as the signal receiving unit. This piezoelectric element converts the received acoustic wave vibrations into a corresponding electrical signal through the piezoelectric effect. However, this traditional "single-ended" receiving scheme has two inherent and insurmountable technical drawbacks: First, the output signal amplitude is limited. The output signal amplitude of a single piezoelectric element directly depends on the received sound pressure level. In scenarios with high sound wave attenuation or long transmission distances, the received sound wave energy is weak, resulting in a very low amplitude of the converted electrical signal. This not only requires the subsequent amplifier to have extremely high gain and extremely low noise, but also makes the signal more susceptible to degradation by internal noise in the subsequent circuit system during transmission and processing. Second, and more critically, it is susceptible to interference from environmental common-mode noise. As a "single-ended" sensor, the output signal of a single piezoelectric element is referenced to ground. In actual working environments, the receiver will not only receive the target acoustic wave, but will also inevitably be affected by various noises from spatial electromagnetic interference, circuit ground fluctuations, and non-target sound sources (such as environmental vibrations). These noises typically act as "common-mode," meaning their amplitude and phase are essentially the same, affecting the entire receiving system. Because single-ended receivers lack an inherent noise discrimination mechanism, they indiscriminately convert valid signals and various types of environmental noise into electrical signals for output. While subsequent circuits can employ filtering and other methods, they struggle to distinguish noise overlapping with the valid signal's frequency band, leading to a decrease in the system's signal-to-noise ratio, reduced measurement accuracy, or increased communication error rate.

[0003] To improve the signal-to-noise ratio, existing technologies typically resort to complex signal processing algorithms, adding shielding structures, or using multiple sensors for spatial filtering. While these methods are effective to some extent, they often come at the cost of increased system complexity, power consumption, and cost, and are essentially "post-hoc remedies" performed after the signal is generated, failing to address the problem at its physical source.

[0004] Therefore, there is a lack of a fundamental solution in the existing technology that can actively enhance the signal and suppress noise at the very moment when the sound wave signal is converted into an electrical signal from a physical level. Summary of the Invention

[0005] This invention provides a method and system for enhancing differential acoustic signals, which solves the problem that acoustic signals are susceptible to environmental common-mode noise when converted into electrical signals.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for enhancing differential acoustic signals includes: Send acoustic signals to the differential receiving unit; The differential receiving unit receives the acoustic wave signal and outputs two electrical signals with opposite phases: a first electrical signal and a second electrical signal. The differential signal is calculated based on the first and second electrical signals.

[0007] Preferably, the differential signal is calculated based on the first electrical signal and the second electrical signal as follows: V diff (t) = V1(t) - V2(t), Where V1(t) represents the first electrical signal, V2(t) represents the second electrical signal, and V diff (t) represents the output differential signal.

[0008] A differential acoustic signal enhancement system, comprising: Sound wave transmitting device: used to transmit sound wave signals to the differential receiving unit; Differential receiver unit: used to receive acoustic wave signals and output two electrical signals with opposite phases, namely a first electrical signal and a second electrical signal; The differential receiving unit includes a first piezoelectric element and a second piezoelectric element arranged in parallel, wherein the polarization directions of the first piezoelectric element and the second piezoelectric element are opposite to each other; Signal processing unit: used to calculate the differential signal based on the first electrical signal and the second electrical signal.

[0009] Preferably, the first piezoelectric element and the second piezoelectric element arranged in parallel are specifically configured as follows: The first piezoelectric element and the second piezoelectric element are fixed on the same support in parallel, and the line connecting the centers of the first piezoelectric element and the second piezoelectric element forms an angle of 85° to 95° with the direction of propagation of the sound wave signal.

[0010] Preferably, the support is a printed circuit board, and the first piezoelectric element and the second piezoelectric element are fixed to the electrode pads on the surface of the printed circuit board by conductive adhesive material, and are electrically connected and signal output through the printed circuit.

[0011] Preferably, the signal processing unit is electrically connected to the differential receiving unit and is configured to receive the two electrical signals with opposite phases, and perform a subtraction operation on the two signals to output an enhanced differential signal.

[0012] Preferably, the first piezoelectric element and the second piezoelectric element are made of any one of lead zirconate titanate piezoelectric ceramic material, single crystal piezoelectric material, piezoelectric composite material or organic polymer piezoelectric material.

[0013] Preferably, the first piezoelectric element and the second piezoelectric element have the same geometry and size, and the resonant frequencies of the first piezoelectric element and the second piezoelectric element are matched.

[0014] Preferably, it further includes a housing, in which the differential receiving unit is encapsulated, the housing being made of an acoustically transmissive material.

[0015] An acoustic communication system, the system comprising: The aforementioned differential acoustic signal enhancement system is used as the receiver of the system. A sound wave signal transmitting device used to generate and transmit modulated sound wave signals; The differential signal output by the acoustic differential signal enhancement system is used for demodulation to recover the transmitted information.

[0016] Compared with existing technologies, the present invention has the following advantages: The present invention provides a method for enhancing acoustic differential signals. By outputting first and second electrical signals with opposite phases through a differential receiving unit and calculating the differential signal, the signal amplitude can be enhanced from the physical source. Simultaneously, the differential characteristics are used to effectively suppress common-mode noise, improving the signal-to-noise ratio and fidelity of the acoustic signal. It eliminates the need for complex signal processing algorithms, additional shielding structures, or multi-sensor spatial filtering and other post-processing remedial measures, simplifying system design, reducing system complexity, power consumption, and cost, and ensuring the reliability and effectiveness of subsequent signal processing.

[0017] This invention also provides a differential acoustic signal enhancement system. Through the coordinated configuration of an acoustic wave transmitting device, a differential receiving unit, and a signal processing unit, and with the help of first and second piezoelectric elements arranged in parallel with opposite polarization directions in the differential receiving unit, the system can actively enhance the signal and suppress common-mode noise at the physical level in the initial stage of converting the acoustic wave signal into an electrical signal, thereby improving the signal quality from the source. This eliminates the need for complex subsequent remedial measures, simplifies the system architecture, reduces power consumption and cost, and the differential receiving unit structure makes the enhanced signal more stable and reliable, adapting to the performance requirements of various acoustic wave application scenarios. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram illustrating the principle of a differential acoustic signal enhancement method provided in an embodiment of the present invention. Figure 2 This is an abstract structural block diagram of the acoustic differential signal enhancement system provided in an embodiment of the present invention; Figure 3 The waveform diagrams showing the performance comparison between differential signals and single-ended signals provided in the embodiments of the present invention are shown above, with the single-ended signal at the top and the differential signal at the bottom. Figure 4 The measured waveform diagram of the method provided in the embodiment of the present invention in 50kb / s digital communication; Figure 5 The measured waveform diagram of the method provided in the embodiment of the present invention in 100kb / s digital communication; Figure 6 The measured waveform diagram of the method provided in the embodiment of the present invention in 200kb / s digital communication; Figure 7 This is a schematic diagram illustrating the application of the method and apparatus provided in embodiments of the present invention in various acoustic systems. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0022] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0023] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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 limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this invention, it should be noted that unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," and "set up" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components.

[0024] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0025] like Figure 1 As shown, this embodiment of the invention provides a method for enhancing differential acoustic signals, including: Send acoustic signals to the differential receiving unit; The differential receiving unit receives the acoustic wave signal and outputs two electrical signals with opposite phases: a first electrical signal and a second electrical signal. The differential signal is calculated based on the first and second electrical signals.

[0026] The differential signal is specifically obtained by calculating based on the first and second electrical signals as follows: V diff (t) = V1(t) - V2(t), Where V1(t) represents the first electrical signal, V2(t) represents the second electrical signal, and V diff (t) represents the output differential signal.

[0027] The core innovation of this method lies in its unique physical structure design, which directly generates the original differential electrical signal at the initial stage of acoustic signal reception. This fundamentally solves the technical problems of limited signal amplitude and susceptibility to common-mode noise interference inherent in traditional single-ended reception methods. By outputting first and second electrical signals with opposite phases through the differential receiving unit and calculating the differential signal, the signal amplitude can be enhanced from the physical source. At the same time, the differential characteristics are used to effectively suppress common-mode noise, improving the signal-to-noise ratio and fidelity of the acoustic signal. It eliminates the need for complex signal processing algorithms, additional shielding structures, or multi-sensor spatial filtering, simplifying system design, reducing system complexity, power consumption, and cost, and ensuring the reliability and effectiveness of subsequent signal processing.

[0028] The specific implementation of this method is as follows: First, two functional elements with piezoelectric properties need to be prepared: a first piezoelectric element and a second piezoelectric element. These two elements have a fundamental difference in material properties: their polarization directions are intentionally set to be completely opposite. These two elements can be made of lead zirconate titanate (PZT) piezoelectric ceramic material, or other types of piezoelectric materials such as single-crystal piezoelectric materials, piezoelectric composite materials, or organic polymer piezoelectric materials are also suitable.

[0029] In terms of structural arrangement, the first and second piezoelectric elements are arranged closely side-by-side to ensure that they are in the same or similar positions in physical space. This strict arrangement is designed to ensure that when an acoustic signal is emitted from the same source and propagates to the receiver, both piezoelectric elements can simultaneously receive essentially the same acoustic signal. To achieve optimal signal reception, the center line connecting the two elements should be set perpendicular to or approximately perpendicular to the main propagation direction of the acoustic signal, with an approximately perpendicular angle of 85° to 95°.

[0030] When an acoustic signal acts simultaneously on two piezoelectric elements with opposite polarization directions, based on the physical principle of the piezoelectric effect, each element converts the received mechanical vibration energy into a corresponding electrical signal. Because the two elements have opposite polarization directions, the electrical signals excited by the same mechanical vibration in the two elements exhibit completely opposite phase characteristics. Specifically, the first piezoelectric element outputs a first electrical signal, while the second piezoelectric element outputs a second electrical signal. These two signals are similar in amplitude but differ in phase by 180 degrees, thus naturally forming an ideal differential signal pair.

[0031] This method of generating differential signals directly at the physical level has significant technical advantages: on the one hand, it avoids the complex process of generating differential signals through subsequent circuits in traditional designs; on the other hand, it provides high-quality raw differential signals for subsequent signal processing, laying a solid foundation for improving the overall system performance.

[0032] like Figure 2 As shown, the present invention also provides a structural block diagram of an acoustic differential signal enhancement system for implementing the above-described method. The core component of this device is a differential receiving unit, which consists of the aforementioned first and second piezoelectric elements with opposite polarization directions. These two elements are physically adjacent, and their electrical connections are carefully designed to ensure independent output of the converted electrical signal.

[0033] In practical applications, to optimize the overall system performance, the device may optionally include a signal processing unit. This unit is electrically connected to the differential receiving unit and is specifically designed to process two out-of-phase electrical signals output from the differential receiving unit. The core function of the signal processing unit is to perform a subtraction operation on these two signals, the mathematical expression of which is V. diff (t) = V1(t) - V2(t), where V1(t) represents the first electrical signal, V2(t) represents the second electrical signal, and V diff (t) represents the final differential output signal after processing.

[0034] From a physical perspective, since V1(t) and V2(t) are out of phase and have similar amplitudes, the amplitude of the effective signal can theoretically be doubled after the subtraction operation, while noise in the environment in common-mode form will be significantly suppressed. In practical implementation, the signal processing unit can be implemented in various forms, including but not limited to differential amplifiers, instrumentation amplifiers, or other integrated circuits with subtraction functions. This design flexibility allows the invention to adapt to the specific needs of different application scenarios.

[0035] In another embodiment, a housing is also included, in which the differential receiving unit is encapsulated, the housing being made of an acoustically transmissive material.

[0036] like Figure 3 As shown in the figure, in order to verify the actual effect of the technical solution described in this invention, we conducted a detailed experimental study. The accompanying figure, through waveform comparison, visually demonstrates the significant performance difference between the differential reception scheme provided by this invention and the traditional single-ended reception scheme.

[0037] Experimental data shows that the peak-to-peak voltage (Vpp) of the two original electrical signal waveforms output from the positive and negative polarization elements is approximately 275 millivolts, and it can be clearly observed that the two signals are completely opposite in phase. This phenomenon is in perfect agreement with theoretical predictions, verifying the correctness of the positive and negative polarization design in naturally generating electrical signals with opposite phases.

[0038] More importantly, after subtracting these two signals with opposite phases, the resulting differential signal waveform exhibits a peak-to-peak voltage of approximately 541 millivolts. This value is very close to twice that of the single-ended signal (the theoretical calculated value is 550 millivolts), fully demonstrating that the technical solution of this invention can effectively double the signal amplitude. Simultaneously, a comparison of the waveforms before and after processing clearly shows that background noise fluctuations in the differential signal waveform are significantly suppressed, demonstrating the superior common-mode noise suppression capability of this invention.

[0039] like Figure 4 , 5 As shown in Figure 6, to further evaluate the performance of this invention in practical application scenarios, we specifically designed a digital communication test experiment. The attached figure illustrates the measured waveform results of OOK (on-off keying) modulation communication using the method of this invention under different data transmission rates.

[0040] The tests covered three different data transmission rates: 50kb / s, 100kb / s, and 200kb / s. For each rate, the graph provides a two-tiered waveform display: the upper waveform shows the original inverted signals output by the two receiving elements, and the lower waveform shows the differential signal after subtraction. Detailed analysis of the waveforms clearly shows that at all test rates, the differential signal waveform can clearly and without distortion reproduce the OOK on / off mode modulated by the binary sequence "01011000".

[0041] This experimental result has significant practical implications. It not only verifies the feasibility of the method of this invention in digital communication, but more importantly, it demonstrates that the method can maintain stable high performance at different communication rates. In particular, at a higher transmission rate of 200kb / s, the system still maintains good signal integrity, indicating that the technical solution of this invention has the potential to meet the needs of high-speed communication.

[0042] In terms of specific physical implementation, this invention provides several feasible embodiments. In a preferred embodiment, the first and second piezoelectric elements are fixed in parallel to a unified support structure using a conductive adhesive material (such as conductive silver paste). This support structure can be a printed circuit board (PCB) or other suitable substrate material. This design not only provides stable mechanical support but also facilitates reliable electrical connections.

[0043] To achieve optimal signal conversion efficiency, the two piezoelectric elements should have identical geometry and dimensions, and their resonant frequencies need to be carefully matched. Regarding material selection, in addition to the aforementioned PZT piezoelectric ceramics, single-crystal piezoelectric materials, piezoelectric composite materials, or organic polymer piezoelectric materials can be selected based on specific application requirements. To protect these precision components from environmental factors, the entire differential receiving unit can be encapsulated in a housing made of an acoustically transmissive material (such as a specific type of plastic or epoxy resin), which provides necessary protection while ensuring effective transmission of the acoustic signal.

[0044] like Figure 7 As shown, the present invention also illustrates the application of the method and apparatus in various acoustic wave systems, demonstrating the wide applicability and significant value of this technical solution.

[0045] In acoustic communication systems, the acoustic differential signal enhancement system described in this invention serves as the receiver, working in conjunction with an acoustic signal transmitter. The transmitter generates and transmits a modulated acoustic signal, which can be modulated using amplitude shift keying (ASK), frequency shift keying (FSK), or phase shift keying (PSK). The high signal-to-noise ratio differential signal output from the receiver is used in the demodulation process, significantly reducing the communication error rate, improving the reliability of the communication link, and effectively extending the maximum communication distance at the same transmit power.

[0046] In acoustic imaging systems, the device of this invention can be used as an echo receiving probe. Its output differential signal, enhanced with improved signal-to-noise ratio, is transmitted to a dedicated image processing unit to construct high-quality acoustic images. This method significantly reduces background noise in the images, making tissue details and boundaries more clearly discernible, thus providing more reliable image data for medical diagnosis and industrial inspection.

[0047] In acoustic energy harvesting systems, the device of this invention can efficiently receive acoustic energy from the environment or specially emitted sound waves. Because the differential output mechanism effectively multiplies the signal amplitude, subsequent energy conversion and management circuits (including rectifier circuits, voltage regulator circuits, etc.) can process the electrical signal with higher efficiency, thereby significantly improving the overall efficiency of capturing and converting acoustic energy from the environment and providing a more stable energy supply for various low-power electronic devices.

[0048] In acoustic wave sensing system applications, the device of this invention is used to detect changes in the physical parameters of acoustic waves with high precision, such as transit time, Doppler frequency shift, and sound attenuation. A dedicated computing unit, based on the characteristics of the enhanced differential signal, can achieve higher precision, greater robustness, and higher sensitivity in physical quantity measurements. Specific applications include, but are not limited to, distance measurement, flow velocity monitoring, medium density analysis, or material defect detection.

[0049] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or basic characteristics. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0050] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for enhancing differential acoustic signals, characterized in that, include: Send acoustic signals to the differential receiving unit; The differential receiving unit receives the acoustic wave signal and outputs two electrical signals with opposite phases: a first electrical signal and a second electrical signal. The differential signal is calculated based on the first and second electrical signals.

2. The method for enhancing differential acoustic signals according to claim 1, characterized in that, The differential signal is specifically obtained by calculating based on the first and second electrical signals as follows: V diff (t)=V1(t)-V2(t), Where V1(t) represents the first electrical signal, V2(t) represents the second electrical signal, and V diff (t) represents the output differential signal.

3. A differential acoustic signal enhancement system, characterized in that, The apparatus is configured to implement a differential acoustic signal enhancement method as described in any one of claims 1 to 2, comprising: Sound wave transmitting device: used to transmit sound wave signals to the differential receiving unit; Differential receiver unit: used to receive acoustic wave signals and output two electrical signals with opposite phases, namely a first electrical signal and a second electrical signal; The differential receiving unit includes a first piezoelectric element and a second piezoelectric element arranged in parallel, wherein the polarization directions of the first piezoelectric element and the second piezoelectric element are opposite to each other; Signal processing unit: used to calculate the differential signal based on the first electrical signal and the second electrical signal.

4. The acoustic differential signal enhancement system according to claim 3, characterized in that, The first and second piezoelectric elements arranged side by side are specifically configured as follows: The first piezoelectric element and the second piezoelectric element are fixed on the same support in parallel, and the line connecting the centers of the first piezoelectric element and the second piezoelectric element forms an angle of 85° to 95° with the direction of propagation of the sound wave signal.

5. The acoustic differential signal enhancement system according to claim 4, characterized in that, The support is a printed circuit board. The first piezoelectric element and the second piezoelectric element are fixed to the electrode pads on the surface of the printed circuit board by conductive adhesive material, and are electrically connected and signal output through the printed circuit.

6. The acoustic differential signal enhancement system according to claim 3, characterized in that, The signal processing unit is electrically connected to the differential receiving unit and is configured to receive the two electrical signals with opposite phases, and perform a subtraction operation on the two signals to output an enhanced differential signal.

7. The acoustic differential signal enhancement system according to claim 3, characterized in that, The first piezoelectric element and the second piezoelectric element are made of any one of lead zirconate titanate piezoelectric ceramic material, single crystal piezoelectric material, piezoelectric composite material or organic polymer piezoelectric material.

8. The acoustic differential signal enhancement system according to claim 3, characterized in that, The first piezoelectric element and the second piezoelectric element have the same geometry and size, and the resonant frequencies of the first piezoelectric element and the second piezoelectric element are matched.

9. The acoustic differential signal enhancement system according to claim 3, characterized in that, It also includes a housing, in which the differential receiving unit is encapsulated, the housing being made of an acoustically transmissive material.

10. An acoustic communication system, characterized in that, The system includes: The acoustic differential signal enhancement system as described in any one of claims 3 to 9 serves as the receiving end of the system; A sound wave signal transmitting device used to generate and transmit modulated sound wave signals; The differential signal output by the acoustic differential signal enhancement system is used for demodulation to recover the transmitted information.

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