Dual-band high-directivity topological acoustic wave receiving antenna

Abstract

The application belongs to the technical field of acoustic antennas, and particularly relates to a dual-band high-directivity topological acoustic receiving antenna. The left side surface, the upper side surface, the lower side surface and the rear end surface are mutually spliced to form a single-port acoustic waveguide, so that the right side of the single-port acoustic waveguide is an open port, the single-port acoustic waveguide is a parallelogram structure, and a topological phononic crystal and a sound-absorbing sponge are arranged in the single-port acoustic waveguide. Through the structure, high-directivity reception of two different voice frequency band acoustic waves can be realized, and an anti-interference high-security acoustic communication function is realized. Meanwhile, the acoustic receiving antenna has the characteristics of dual working frequency bands, small size, light weight and convenience in carrying, has high-directivity receiving effect on two independent wide frequency band acoustic signals, provides a feasible solution for voice frequency band acoustic signal directivity anti-interference and security transmission, and can be applied to the field of artificial intelligence robots.

Description

Technical Field

[0001] This invention belongs to the field of acoustic antenna technology, specifically relating to a dual-band high-directivity topological acoustic wave receiving antenna. Background Technology

[0002] In real-world acoustic environments, the presence of harmful interference echoes and noise sources makes accurately and clearly capturing acoustic signals from target sound sources and achieving high signal-to-noise ratio communication a significant scientific challenge. For example, novel AI robots require directional sound wave reception capabilities to ensure accurate signal reception in noisy environments, enabling their application in various complex scenarios. Furthermore, when multiple novel robots operate in the same environment, directional sound wave reception ensures that each robot can receive its corresponding target acoustic signal independently, allowing them to work without interfering with each other. Therefore, achieving highly directional reception of multi-speech audio bands is not only a crucial scientific problem but also holds significant application potential in fields such as artificial intelligence and robotics.

[0003] To address this scientific challenge, the large active arrays and complex processing systems in traditional phased array microphone array technology are highly detrimental to the miniaturization and integration of acoustic devices, significantly limiting their application scenarios. Furthermore, receiving antennas based on acoustic metamaterials often operate at a single frequency, limiting their application potential. Therefore, there is an urgent need to develop highly directional acoustic wave receiving antennas with anti-interference capabilities, high signal-to-noise ratios, and multiple operating frequency bands.

[0004] In view of this, in order to solve the above problems, the present invention designs a dual-band high-directivity topological acoustic wave receiving antenna. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to address the shortcomings of current technology by providing a dual-band highly directional topological acoustic wave receiving antenna with anti-interference capability, high signal-to-noise ratio, and multiple operating frequency bands.

[0006] Technical solution: To achieve the above objectives, the present invention provides a dual-band high-directivity topological acoustic wave receiving antenna, comprising a single-port acoustic waveguide, a topological phononic crystal, and sound-absorbing sponge;

[0007] The single-port acoustic waveguide has a parallelogram structure and includes a left side, a top side, a bottom side, and a rear end face. The left side, top side, and bottom side are respectively vertically mounted on the left, top, and bottom ends of the rear end face. The top and bottom ends of the left side are respectively connected to the top and bottom sides. The top, bottom, and left sides are all rectangular plates. The right side of the single-port acoustic waveguide is an open port.

[0008] The topological phononic crystal includes a resonant unit, which is labyrinth-shaped and comprises three 120° fan-shaped acoustic waveguides. The resonant unit is fixedly mounted on the rear end face. The topological phononic crystal is divided into an upper half-region topological phononic crystal and a lower half-region topological phononic crystal in the single-port acoustic waveguide. The two-dimensional plane rotation angle of the resonant unit of the upper half-region topological phononic crystal is 21˚, and the two-dimensional plane rotation angle of the resonant unit of the lower half-region topological phononic crystal is -39˚.

[0009] The sound-absorbing sponge is installed on the rear end face.

[0010] Furthermore, the single-port acoustic waveguide is made of epoxy resin or nylon; the single-port acoustic waveguide is manufactured using 3D printing or injection molding processes.

[0011] Furthermore, the resonant unit is made of epoxy resin or nylon; the resonant unit is manufactured using 3D printing or injection molding processes.

[0012] Furthermore, the sound-absorbing sponge is made of polyurethane foam.

[0013] Furthermore, the number of resonant units is 40.

[0014] Beneficial effects: This invention utilizes the characteristics of acoustic valley projection topological boundary states without backscattering and the physical nature of valley projection to achieve dual-band high directivity reception of speech frequency band sound waves. It can be applied to intelligent robots to achieve anti-interference and high-security acoustic communication functions.

[0015] The acoustic receiving antenna proposed in this invention features dual operating frequency bands, small size, light weight, and portability. It has high directivity reception for acoustic signals in two independent widebands, providing a feasible solution for directional anti-interference and secure transmission of audio signals in the speech band. It can be applied to fields such as artificial intelligence robots. Attached Figure Description

[0016] Figure 1 This is a structural diagram of the topological acoustic wave receiving antenna of the present invention.

[0017] Figure 2 (a) is a schematic diagram of the primitive cell structure when the two-dimensional plane of the resonant unit is rotated by an angle of -9˚;

[0018] Figure 2(b) shows the dispersion curve obtained along the path of the high symmetry point of the first Brillouin zone, as shown in the inset.

[0019] Figure 3 (a) is a schematic diagram of the primitive cell structure when the two-dimensional plane rotation angle of the resonant unit is 21˚;

[0020] Figure 3(b) shows the dispersion curve corresponding to the structure in Figure 3(a);

[0021] Figure 3(c) is a schematic diagram of the primitive cell structure when the two-dimensional plane rotation angle of the resonant unit is -39˚;

[0022] Figure 3(d) shows the dispersion curves corresponding to the structure in Figure 3(c); the two topological phononic crystals have opposite valley Chern numbers in each band gap and are marked in Figure 3(b) and Figure 3(d) respectively.

[0023] Figure 4(a) is a schematic diagram of the structure of the banded topological phononic crystal and its boundary;

[0024] Figure 4(b) shows the corresponding dispersion curve.

[0025] Figure 5(a) shows the field distribution of acoustic energy captured by the antenna from a signal source at a specified angle when the operating frequency is 1.7 kHz. The white dashed arrows represent the theoretical receiving angle.

[0026] Figure 5(b) shows the field distribution when the signal source is located at a non-specified angle but at the same operating frequency;

[0027] Figure 5(c) is a momentum space schematic diagram of acoustic energy directivity reception at an operating frequency of 1.7 kHz.

[0028] Figure 5(d) shows the field distribution of acoustic energy captured by the antenna from a signal source at a specified angle when the operating frequency is 2.4 kHz. The white dashed arrows represent the theoretical receiving angle.

[0029] Figure 5(e) shows the field distribution when the signal source is located in a non-specified direction but at the same operating frequency;

[0030] Figure 5(f) is a momentum space schematic diagram of acoustic energy directivity reception at an operating frequency of 2.4 kHz.

[0031] The operating frequency band corresponding to Figure 6(a) is 1.6 ~ 1.85 kHz;

[0032] The operating frequency band corresponding to Figure 6(b) is 2.2 ~ 2.5 kHz, and the white dashed line represents the theoretical receiving angle.

[0033] List of reference numerals in the attached diagram: 1. Single-port acoustic waveguide; 101. Left side face; 102. Upper side face; 103. Lower side face; 104. Rear end face; 2. Topological phononic crystal; 3. Sound-absorbing sponge; 4. Resonant unit; 5. Topological phononic crystal in the upper half region; 6. Topological phononic crystal in the lower half region. Detailed Implementation

[0034] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. It should be noted that the terms "front," "rear," "left," "right," "up," and "down" used in the following description refer to directions in the accompanying drawings, and the terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0035] Example 1, according to Figure 1 Figure 6(b) provides further explanation.

[0036] This invention provides a dual-band high-directivity topological acoustic wave receiving antenna, comprising a single-port acoustic waveguide 1, a topological phononic crystal 2, and a sound-absorbing sponge 3;

[0037] The single-port acoustic waveguide 1 has a parallelogram structure and includes a left side face 101, an upper side face 102, a lower side face 103, and a rear end face 104. The left side face 101, upper side face 102, and lower side face 103 are respectively vertically mounted on the left, upper, and lower ends of the rear end face 104. The upper and lower ends of the left side face 101 are connected to the upper side face 102 and the lower side face 103, respectively. The upper side face 102, lower side face 103, and left side face 101 are all rectangular plates. The right side face of the single-port acoustic waveguide 1 is an open port. The lengths of the upper side face 102, lower side face 103, and rear end face 104 are 36 cm, 36 cm, and 82.3 cm, respectively. The wall thickness of the single-port acoustic waveguide 1 is 1 cm, and the height is 7 cm, that is, the wall thickness of the left side face 101, upper side face 102, and lower side face 103 is 1 cm, and the height is 7 cm.

[0038] The topological phononic crystal 2 includes at least two resonant units 4, and the number of topological phononic crystals 2 is 20. The resonant units 4 are labyrinth-shaped, with a height of 7 cm and a lattice constant of 8 cm. Each resonant unit 4 includes three 120° fan-shaped acoustic waveguides, wherein the wall thickness of the acoustic waveguide is 0.304 cm, the width is 0.608 cm, the inner diameter is 0.304 cm, and the outer diameter is 3.04 cm. The resonant units 4 are fixedly mounted on the rear end face 104. The topological phononic crystal 2 is divided into an upper half-region topological phononic crystal 5 and a lower half-region topological phononic crystal 6 in the single-port acoustic waveguide 1. The two-dimensional plane rotation angle of the resonant unit 4 of the upper half-region topological phononic crystal 5 is 21˚, and the two-dimensional plane rotation angle of the resonant unit 4 of the lower half-region topological phononic crystal 6 is -39˚. An acoustic topological boundary is formed between these two structures that have opposite valley Hall topological phases in any band gap.

[0039] The sound-absorbing sponge 3 is installed on the rear end face 104.

[0040] The single-port acoustic waveguide 1 is made of epoxy resin or nylon and is manufactured using 3D printing or injection molding. The resonant unit 4 is made of epoxy resin or nylon and is manufactured using 3D printing or injection molding. The sound-absorbing sponge 33 is made of polyurethane foam and has a thickness of 4 cm.

[0041] See Figure 1 The single-port acoustic waveguide 1, in its top view, is a parallelogram, with top, bottom, and rear end lengths of 36 cm, 36 cm, and 82.3 cm, respectively. It is open at the front end, has a wall thickness of 1 cm, and a height of 7 cm. Next, 20 resonant units 4 from the topological phononic crystal 2 are arranged in the single-port acoustic waveguide 1 according to their respective positions and rotation angles. Each resonant unit 4 has a height of 7 cm and a lattice constant of 8 cm. Each resonant unit 4 consists of three 120˚ fan-shaped zigzag acoustic waveguides, with a wall thickness of 0.304 cm, a width of 0.608 cm, an inner diameter of 0.304 cm, and an outer diameter of 3.04 cm. The upper half of the single-port acoustic waveguide 1 is arranged with resonant units 4 at a two-dimensional plane rotation angle of 21˚, and the lower half is arranged with resonant units 4 at a two-dimensional plane rotation angle of -39˚. These two structures, which possess opposite valley Hall topological phases in any bandgap, form a dual-band acoustic wave topological interface. The distance from the center of the bottommost resonant unit 4 to the left boundary of the single-port acoustic waveguide 1 is 6.93 cm, and the vertical distance to the bottom boundary of the single-port acoustic waveguide 1 is 3.46 cm. (The distance is along the triangular lattice basis vectors.) a 1. a 2. By performing translation, the specific positions of the remaining nineteen topological phonon crystals 2 can be obtained. Finally, three layers of acoustic sound-absorbing sponge with a thickness of 4 cm are wrapped around the rear end of the single-port acoustic waveguide 1.

[0042] Referring to Figures 2(a)-2(b), for the topological phononic crystal 2 composed of resonant units 4 with a rotation angle of 9˚, two band-degenerate Dirac cones are obtained at different frequencies of the high symmetry point in its first Brillouin zone, with frequencies of 1.745 kHz and 2.385 kHz, respectively. Next, by rotating the resonant units 4 clockwise and counterclockwise, two types of topological phononic crystals 2 with different valley Chern numbers in any band gap are generated.

[0043] Referring to Figures 3(a)-3(d), a resonant unit 4 with a rotation angle of 21˚ is obtained by rotating the resonant unit 4 clockwise, as shown in Figure 3(a). The dispersion curve of the topological phononic crystal 2 formed by this resonant unit 4 is shown in Figure 3(b). At this time, the original two Dirac cones of different frequencies are broken, forming bulk band gaps in different frequency ranges. The valley Chern number corresponding to the low-frequency band gap of this topological phononic crystal 2 is... , The valley number corresponding to the high-frequency bandgap is , The topological phonon crystal 2 corresponding to the resonant unit 4 with a rotation angle of -39˚ in Figure 3(c) has the same bandgap as the topological phonon crystal 2 in Figure 3(a), but its valley Chern number is opposite. The valley Chern number corresponding to the low-frequency bandgap is... , The valley number corresponding to the high-frequency bandgap is , .

[0044] Referring to Figures 4(a)-4(b), a phononic crystal is constructed using the two types of resonant units 4 described in Figures 3(a)-3(d). The upper half consists of resonant units 4 with a rotation angle of 21˚, and the lower half consists of resonant units 4 with a rotation angle of -39˚. x Figure 4(a) shows a band-shaped topological phononic crystal with a periodic boundary, and Figure 4(b) shows the calculated dispersion curve. The dispersion curve reveals the existence of topological boundary states that traverse the entire bandgap. These boundary states arise from the different valley Chern numbers at the two ends of the boundary. For the low-frequency band, the valley Chern number at point K varies... Therefore, the topological boundary states of the K-valley projection will propagate in the negative direction; while... The number of points and valleys changes as follows ,so The topological boundary states of the valley projection will propagate in the positive direction; for the high-frequency band, the situation is completely reversed, and the valley Chern number at point K changes as follows: , The changes in the number of points and valleys are as follows: Therefore, the topological boundary states of the K-valley projection will propagate in the positive direction. The topological boundary states of the valley projection will propagate in the negative direction.

[0045] The invention will now be further illustrated with examples.

[0046] Referring to Figures 5(a)-5(f), the dual-band high-directivity topological acoustic wave receiving antenna of the present invention is placed in a semi-circular free space. Finite element method software is used to simulate and calculate the field distribution after acoustic waves with frequencies of 1.7 kHz and 2.4 kHz are coupled from the free space to the topological boundary along a specified receiving angle. The acoustic wave input port surface of the acoustic wave receiving antenna is horizontal. Simulation results show that the topological antenna of the present invention can couple along the angle... β L and β HThis achieves highly directional reception of sound waves in both low and high frequency bands, while signals from other incident angles are not captured by the antenna. This reception capability originates from the boundary states of valley projection. Specifically, for the low-frequency band, since sound waves propagate negatively when entering the topological boundary, the low-frequency topological boundary states in this example are obtained by K-valley projection; for the high-frequency band, the corresponding topological boundary states are obtained by... The angle of reception of the incident sound wave is obtained by valley projection. To obtain the reception angle, the first Brillouin zone (hexagonal wireframe) of the topological phonon crystal 2 and the isofrequency lines (circles) of the sound wave propagating in free space are drawn to scale in Figures 5(c) and 5(f). The reception angle can be obtained from the transverse wave vector matching relationship of the sound wave at different medium interfaces, i.e. ,in K Indicates the incident wave vector. k Denotes the wave vector in free space. e term This is the unit direction vector at the incident end boundary, with the direction of the incident port surface represented by a dotted line. The low-frequency (high-frequency) receiving angle is theoretically calculated. β L = 32.8° β H = 129.4°), and marked with white dashed arrows and black solid arrows in Figures 5(a), 5(d) and 5(c) (5(f)), respectively.

[0047] Referring to Figures 6(a)-6(b), the broadband function of the dual-band high directivity topology acoustic wave receiving antenna of the present invention is further explained. It can be seen that within the operating frequency range of 1.6 ~ 1.85 kHz and 2.2 ~ 2.5 kHz, the acoustic waves received by the designed acoustic wave receiving antenna have good directivity. The white dashed line represents the theoretically calculated reception angle, which is consistent with the simulation results.

[0048] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A dual-band high-directivity topological acoustic wave receiving antenna, characterized in that: It includes a single-port acoustic waveguide (1), a topological phononic crystal (2), and a sound-absorbing sponge (3); The single-port acoustic waveguide (1) has a parallelogram structure. The single-port acoustic waveguide (1) includes a left side (101), an upper side (102), a lower side (103), and a rear end (104). The left side (101), the upper side (102), and the lower side (103) are respectively vertically installed on the left end, the upper end, and the lower end of the rear end (104). The upper end and the lower end of the left side (101) are respectively connected to the upper side (102) and the lower side (103). The upper side (102), the lower side (103), and the left side (101) are all rectangular plates. The right side of the single-port acoustic waveguide (1) is an open port. The topological phononic crystal (2) includes a resonant unit (4), which is labyrinthine in shape. The resonant unit (4) includes three 120° fan-shaped waveguides. The resonant unit (4) is fixedly mounted on the rear end face (104). The topological phononic crystal (2) is divided into an upper half-region topological phononic crystal (5) and a lower half-region topological phononic crystal (6) in the single-port waveguide (1). The two-dimensional plane rotation angle of the resonant unit (4) of the upper half-region topological phononic crystal (5) is 21˚, and the two-dimensional plane rotation angle of the resonant unit (4) of the lower half-region topological phononic crystal (6) is -39˚. The sound-absorbing sponge (3) is installed on the rear end face (104).

2. The dual-band high-directivity topological acoustic wave receiving antenna according to claim 1, characterized in that: The single-port acoustic waveguide (1) is made of epoxy resin or nylon; the single-port acoustic waveguide (1) is made by 3D printing or injection molding.

3. The dual-band high-directivity topological acoustic wave receiving antenna according to claim 1, characterized in that: The resonant unit (4) is made of epoxy resin or nylon; the resonant unit (4) is made by 3D printing or injection molding.

4. The dual-band high-directivity topological acoustic wave receiving antenna according to claim 1, characterized in that: The sound-absorbing sponge (3) is made of polyurethane foam.

5. A dual-band high-directivity topological acoustic wave receiving antenna according to claim 1, characterized in that: The number of resonant units (4) is 40.

Images