Leaky-wave antenna unit and leaky-wave antenna array

Abstract

The invention discloses a leaky-wave antenna unit and a leaky-wave antenna array. The leaky-wave antenna unit comprises a driving patch, a microstrip feeder, a plurality of low-frequency leaky-wave patches, a plurality of high-frequency leaky-wave patches, a first dielectric plate, a second dielectric plate, a third dielectric plate, a metal reflection floor and a fourth dielectric plate, the multiple low-frequency leaky-wave patches and the multiple high-frequency leaky-wave patches are arranged on the upper surface of the first dielectric plate, the multiple high-frequency leaky-wave patches surround the outer sides of the multiple low-frequency leaky-wave patches, and the distance between every two adjacent high-frequency leaky-wave patches is equal; the driving patch is located between the first dielectric plate and the second dielectric plate, a through hole is formed in the metal reflection floor, the microstrip feeder line is arranged below the fourth dielectric plate, the connecting end of the microstrip feeder line is connected with the feed interface, and the projection of the through hole in the direction perpendicular to the metal reflection floor intersects with the microstrip feeder line. According to the scheme, the use efficiency of the leaky-wave antenna can be improved.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technologies, and more particularly to a leaky wave antenna unit and a leaky wave antenna array. Background Art

[0002] Antenna-in-Package (AiP) technology has become a popular millimeter-wave wireless communication solution in system-in-package applications. It is widely used in 5G millimeter-wave wireless communication systems. In actual usage scenarios, a leaky wave antenna can be used as the Antenna-in-Package for wireless signal transmission and reception.

[0003] Currently, different communication scenarios have different requirements for the antenna bandwidth of the leaky wave antenna. Before installing the leaky wave antenna in the corresponding wireless communication device, it is necessary to estimate the antenna bandwidth of the leaky wave antenna to determine whether the antenna bandwidth of the leaky wave antenna can meet the requirements of the communication scenario. Only when the antenna bandwidth of the leaky wave antenna can meet the requirements of the communication scenario, the leaky wave antenna is installed in the wireless communication device under this communication scenario for use.

[0004] However, the phase shift constants of current leaky wave antennas are not consistent, so it is impossible to quickly estimate the antenna bandwidth of the leaky wave antenna, resulting in a large amount of time being consumed to calculate the antenna bandwidth of the leaky wave antenna before using the leaky wave antenna, reducing the usage efficiency of the leaky wave antenna. Summary of the Invention

[0005] In view of this, the present application provides a leaky wave antenna unit and a leaky wave antenna array, mainly aiming to solve the technical problem of too low usage efficiency of the leaky wave antenna.

[0006] According to a first aspect of the present invention, a leaky wave antenna unit is provided. The leaky wave antenna unit includes a driving patch, a microstrip feeder, a plurality of low-frequency leaky wave patches, a plurality of high-frequency leaky wave patches, and a first dielectric plate, a second dielectric plate, a third dielectric plate, a metal reflection floor, and a fourth dielectric plate stacked in sequence from top to bottom;

[0007] The plurality of low-frequency leaky wave patches and the plurality of high-frequency leaky wave patches are disposed on the upper surface of the first dielectric plate, wherein the plurality of high-frequency leaky wave patches surround the plurality of low-frequency leaky wave patches, and the distance between every two adjacent high-frequency leaky wave patches is equal;

[0008] The driving patch is disposed between the first dielectric plate and the second dielectric plate. The metal reflection floor has a through hole penetrating the metal reflection floor, and the projection of the driving patch in the direction perpendicular to the metal reflection floor intersects with the through hole;

[0009] The microstrip feeder is disposed below the fourth dielectric plate. The connection end of the microstrip feeder is connected to the power feeding interface of the host computer. The projection of the through hole along the direction perpendicular to the metal reflection floor intersects with the microstrip feeder.

[0010] In an optional embodiment, the shape of the low-frequency leaky wave patch is rectangular; a plurality of the low-frequency leaky wave patches form a low-frequency leaky wave metamaterial array on the upper surface of the first dielectric plate. The low-frequency leaky wave metamaterial array includes a first number of low-frequency array rows, and each of the low-frequency array rows includes the first number of low-frequency leaky wave patches; the short sides of each low-frequency leaky wave patch in the low-frequency array row are parallel to each other, and the straight line where the geometric center of each low-frequency leaky wave patch in the low-frequency array row is located is parallel to the long side of each low-frequency leaky wave patch.

[0011] In an optional embodiment, the shape of the high-frequency leaky wave patch is square, and a plurality of the high-frequency leaky wave patches form a high-frequency leaky wave metamaterial array on the upper surface of the first dielectric plate; along the long side direction of the low-frequency leaky wave patch, a second number of the high-frequency leaky wave patches are distributed on each side of the low-frequency leaky wave metamaterial array; along the short side direction of the low-frequency leaky wave patch, a third number of the high-frequency leaky wave patches are distributed on each side of the low-frequency leaky wave metamaterial array.

[0012] In an optional embodiment, the geometric centers of the low-frequency leaky wave metamaterial array, the high-frequency leaky wave metamaterial array, the metal reflection floor, the driving patch, and the through hole coincide with each other in the projection along the direction perpendicular to the metal reflection floor.

[0013] In an optional embodiment, the shapes of the through hole and the driving patch are rectangular respectively; the long side of the through hole is perpendicular to the long side of the driving patch, and the length of the short side of the driving patch is less than the length of the long side of the through hole.

[0014] In an optional embodiment, the long side of the through hole is perpendicular to the microstrip feeder.

[0015] In an optional embodiment, the thicknesses of the first dielectric plate and the third dielectric plate are the same, and the thicknesses of the second dielectric plate and the fourth dielectric plate are the same; the thicknesses of the first dielectric plate and the third dielectric plate are greater than the thicknesses of the second dielectric plate and the fourth dielectric plate.

[0016] In an optional embodiment, there is no electrical connection between any two of the low-frequency leaky wave patches, and the projections of the plurality of low-frequency leaky wave patches on the second dielectric plate along the direction perpendicular to the metal reflection floor surround the driving patch.

[0017] In an optional embodiment, there is no electrical connection between the low-frequency leaky-wave patch and the high-frequency leaky-wave patch.

[0018] According to a second aspect of the present invention, there is provided a leaky-wave antenna array, which includes the leaky-wave antenna unit as described above.

[0019] For the leaky-wave antenna unit and the leaky-wave antenna array provided by the present invention, the low-frequency leaky-wave patch in the leaky-wave antenna unit is surrounded by a plurality of high-frequency leaky-wave patches, and the distance between every two adjacent high-frequency leaky-wave patches is equal, so that the plurality of high-frequency leaky-wave patches uniformly surround the low-frequency leaky-wave patch, making the phase shift constant of the leaky-wave antenna unit the same in the transverse direction, where the transverse direction is the electric field direction of the leaky-wave antenna unit. Therefore, the antenna bandwidth of the leaky-wave antenna unit can be quickly estimated, the bandwidth estimation time required before using the leaky-wave antenna unit is reduced, and the usage efficiency of the leaky-wave antenna is improved.

[0020] The above description is only an overview of the technical solution of this application. In order to be able to understand the technical means of this application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of this application more obvious and understandable, the specific embodiments of this application are specifically given below. Description of the Drawings

[0021] The drawings described herein are used to provide a further understanding of the present invention, and constitute a part of this application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0022] Figure 1 A top view of a current leaky-wave antenna provided by an embodiment of the present invention is shown;

[0023] Figure 2 A cross-sectional view of a leaky-wave antenna unit provided by an embodiment of the present invention is shown;

[0024] Figure 3 A top perspective view of a leaky-wave antenna unit provided by an embodiment of the present invention is shown;

[0025] Figure 4 A diagram showing the gain, reflection coefficient, and frequency of a leaky-wave antenna unit provided by an embodiment of the present invention is shown;

[0026] Figure 5 A phase shift and frequency coordinate diagram based on the dispersion diagram mechanism provided by an embodiment of the present invention is shown;

[0027] Figure 6 A structural diagram of a leaky-wave antenna array provided by an embodiment of the present invention is shown. Detailed Embodiments

[0028] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0029] In order to more clearly and comprehensively elaborate on the technical problems to be solved, the technical solutions, and the beneficial effects of the present application, the following further detailed description of the present application is provided in conjunction with the accompanying drawings and embodiments. It should be emphasized that the specific embodiments mentioned are only for explaining the present application and not for limiting the present application.

[0030] When an element is referred to as being "fixed to" or "disposed on" another element, it means that the element can be directly located on the other element or indirectly connected to the other element. Similarly, when an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element through an intermediate medium. In addition, the terms "first" and "second" are only used for descriptive purposes and do not indicate relative importance or imply the number of the technical features referred to. Therefore, the features with "first" and "second" may include one or more of such features. In the description of the present application, "a plurality" means two or more, and "several" means one or more, and the specific meaning depends on the specific definition. In the description, the orientation indicators such as "above", "below", "front", "rear", "left", and "right" are based on the orientation relationship shown in the accompanying drawings, and are only for the convenience of description and simplification of expression, and do not mean that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, these orientation indicators should not be construed as limitations on the present application. For the terms "installed", "connected", and "coupled", unless otherwise clearly defined and limited, should be understood in a broad sense. This includes, but is not limited to, fixed connection, detachable connection, integral connection, mechanical connection, electrical connection, direct connection, indirect connection through an intermediate medium, and the connection or interaction relationship inside the element. In the present application, the specific meaning of these terms can be understood by those of ordinary skill in the art according to the specific situation.

[0031] Currently, different communication scenarios have different requirements for the antenna bandwidth of leaky wave antennas. Before installing a leaky wave antenna in a corresponding wireless communication device, it is necessary to estimate the antenna bandwidth of the leaky wave antenna to determine whether the antenna bandwidth of the leaky wave antenna can meet the requirements of the communication scenario. When the antenna bandwidth of the leaky wave antenna can meet the requirements of the communication scenario, the leaky wave antenna is set in the wireless communication device for use.

[0032] However, the structural schematic diagram of the existing leaky wave antenna is as Figure 1As shown in the figure, a plurality of low-frequency leaky wave patch units 11 and a plurality of high-frequency leaky wave patch units 12 are provided on the upper surface of the dielectric plate 13 of the leaky wave antenna 10. Among them, all the low-frequency leaky wave patch units 11 form a low-frequency leaky wave array, and the plurality of high-frequency leaky wave patch units 12 are respectively arranged on both sides of the low-frequency leaky wave array along the long side direction of the low-frequency leaky wave patch unit 11. Among them, the long side direction of the low-frequency leaky wave patch unit 11 is the electric field direction of the leaky wave antenna 10, and this electric field direction is the length direction of the microstrip feeder (not shown in the figure) in the leaky wave antenna 10.

[0033] However, in the existing leaky wave antenna 10, high-frequency leaky wave patch units 12 are not provided on both sides of the low-frequency leaky wave array along the short side direction of the low-frequency leaky wave patch unit 11, resulting in vacancies of the high-frequency leaky wave patch units 12 on both sides of the low-frequency leaky wave array along the short side direction of the low-frequency leaky wave patch unit 11. Furthermore, the phase shift constants of the leaky wave antenna 10 in the transverse direction are different, so that the antenna bandwidth of the leaky wave antenna cannot be quickly estimated through the simulation resonance material model and the antenna resonance cavity theory formula. Therefore, a large amount of time is required to calculate the antenna bandwidth of the leaky wave antenna before using the leaky wave antenna, reducing the usage efficiency of the leaky wave antenna.

[0034] In view of the above problems, in one embodiment, as Figure 2 shown, a leaky wave antenna unit is provided. The leaky wave antenna unit includes a driving patch 100, a microstrip feeder 200, a plurality of low-frequency leaky wave patches 300, a plurality of high-frequency leaky wave patches 400, and a first dielectric plate 500, a second dielectric plate 600, a third dielectric plate 700, a metal reflection floor 800, and a fourth dielectric plate 900 stacked in sequence from top to bottom. Among them, the microstrip feeder 200 can be a wire with an open terminal and a resistance value of 50 ohms. Further, as Figure 2 shown, the first dielectric plate 500 makes there be no electrical connection between the driving patch 100 and the low-frequency leaky wave patch 300 and the high-frequency leaky wave patch 400; at the same time, the second dielectric plate 600 and the third dielectric plate 700 make there be no electrical connection between the driving patch 100 and the metal reflection floor 800, and the fourth dielectric plate 900 makes there be no electrical connection between the metal reflection floor 800 and the microstrip feeder 200. The driving patch 100, the low-frequency leaky wave patch 300, and the high-frequency leaky wave patch 400 all use the metal reflection floor 800 as the reflection plane.

[0035] Here, the length and width dimensions of the low-frequency leaky-wave patch 300 can be 0.6 mm × 1.5 mm, the length and width dimensions of the high-frequency leaky-wave patch 400 can be 1 mm × 1 mm, and the length and width dimensions of the driving patch 100 can be 0.15 mm × 1.6 mm. Further, the first dielectric plate 500, the second dielectric plate 600, the third dielectric plate 700, and the fourth dielectric plate 900 can all be high-frequency dielectric plates. By utilizing the performance of the high-frequency dielectric plates, the antenna bandwidth can be increased while reducing the profile. For example, the first dielectric plate 500 and the third dielectric plate 700 can both adopt the HL972 high-frequency dielectric plate, and the second dielectric plate 600 and the fourth dielectric plate 900 can both adopt the GHPL-970 high-frequency dielectric plate.

[0036] Further, as Figure 2 shown, the driving patch 100 is disposed between the first dielectric plate 500 and the second dielectric plate 600, and a through hole 810 extending in the up and down direction and penetrating the metal reflection floor 800 is provided at the metal reflection floor 800. Further, as Figure 3 shown, the projection of the driving patch 100 in the direction perpendicular to the metal reflection floor 800 intersects with the through hole 810, that is, the projection of the driving patch 100 on the metal reflection floor 800 intersects with the through hole 810.

[0037] Further, the microstrip feeder 200 is disposed below the fourth dielectric plate 900, and the connection end of the microstrip feeder 200 is connected to the feeding interface of a host computer (not shown in the figure). Among them, the host computer can be a device such as a wireless communication device. Further, the projection of the through hole 810 in the direction perpendicular to the metal reflection floor 800 intersects with the microstrip feeder 200; specifically, in the direction perpendicular to the plane where the metal reflection floor 800 is located, the through hole 810 is projected onto the microstrip feeder 200, and the projection of the through hole 810 intersects with the microstrip feeder 200.

[0038] Specifically, as Figure 3 shown, a plurality of the low-frequency leaky-wave patches 300 and a plurality of the high-frequency leaky-wave patches 400 are disposed on the upper surface of the first dielectric plate 500. Among them, the upper surface of the first dielectric plate 500 is the first surface of the first dielectric plate 500, the surface of the first dielectric plate 500 opposite to the first surface is the second surface, and the second surface of the first dielectric plate 500 is in contact with the second dielectric plate 600. Further, the low-frequency leaky-wave patches 300 and the high-frequency leaky-wave patches 400 are distributed at intervals, and there is no electrical connection between them. Each low-frequency leaky-wave patch 300 can play an exciting role in each high-frequency leaky-wave patch 400; further, there is no electrical connection between any two low-frequency leaky-wave patches 300.

[0039] Further, a plurality of the high-frequency leaky wave patches 400 surround the outside of the plurality of the low-frequency leaky wave patches 300, and the distance between every two adjacent high-frequency leaky wave patches 400 is equal. Among them, on any side of the low-frequency leaky wave patch 300, the distance between two adjacent high-frequency leaky wave patches 400 can be 0.1 mm. Here, Figure 3 The numbers of the low-frequency leaky wave patches 300 and the high-frequency leaky wave patches 400 shown in

[0040] Here, as Figure 3 shown, because a plurality of high-frequency leaky wave patches 400 evenly surround the low-frequency leaky wave patches 300, high-frequency leaky wave patches 400 are evenly arranged around the low-frequency leaky wave metamaterial array 310 composed of all the low-frequency leaky wave patches 300, so that the phase shift constant of the leaky wave antenna unit in the transverse direction is the same, where the transverse direction is the electric field direction of the leaky wave antenna unit. Therefore, the side lengths of the high-frequency leaky wave patches 400 and the low-frequency leaky wave patches 300 can be obtained, and the resonant points corresponding to the phase shift can be calculated through the simulation resonant material model and the antenna resonant cavity theoretical formula, so as to determine the bandwidth of the leaky wave antenna unit.

[0041] Further, as Figure 3 shown, the shape of the low-frequency leaky wave patch 300 is rectangular, and the shape of the driving patch 100 is rectangular. Further, all the low-frequency leaky wave patches 300 form a low-frequency leaky wave metamaterial array 310 on the upper surface of the first dielectric plate 500, and the low-frequency leaky wave metamaterial array 310 is a rectangular array. Specifically, the low-frequency leaky wave metamaterial array 310 includes a first number of low-frequency array rows, and each of the low-frequency array rows includes the first number of low-frequency leaky wave patches 300; the number of low-frequency array rows in the low-frequency leaky wave metamaterial array 310 is equal to the number of low-frequency leaky wave patches 300 in the low-frequency array rows. Further, the short sides of all the low-frequency leaky wave patches 300 in the low-frequency array rows are parallel to each other. Further, the straight line where the geometric centers of all the low-frequency leaky wave patches 300 in any one low-frequency array row are located is parallel to the long side of each of the low-frequency leaky wave patches 300 in this low-frequency array row, so that a plurality of low-frequency leaky wave patches 300 can form a regular rectangular array. Among them, the value of the first number can be determined according to the actual situation.

[0042] Further, as Figure 3As shown, the shape of the high-frequency leaky-wave patch 400 is square, and all the high-frequency leaky-wave patches 400 form a high-frequency leaky-wave metamaterial array on the upper surface of the first dielectric plate 500, and the shape of the high-frequency leaky-wave metamaterial array is rectangular. Further, along the long side direction of the low-frequency leaky-wave patch 300, the second number of the high-frequency leaky-wave patches 400 are distributed on each side of the low-frequency leaky-wave metamaterial array 310; as an example, if the left side in the long side direction of the low-frequency leaky-wave patch 300 is the left side of the low-frequency leaky-wave metamaterial array 310, and the right side in the long side direction of the low-frequency leaky-wave patch 300 is the right side of the low-frequency leaky-wave metamaterial array 310, then the second number of high-frequency leaky-wave patches 400 are provided on both the left and right sides of the low-frequency leaky-wave metamaterial array 310.

[0043] Further, along the short side direction of the low-frequency leaky-wave patch 300, the third number of the high-frequency leaky-wave patches 400 are distributed on each side of the low-frequency leaky-wave metamaterial array 310. As an example, if the left side in the short side direction of the low-frequency leaky-wave patch 300 is the left side of the low-frequency leaky-wave metamaterial array 310, and the right side in the short side direction of the low-frequency leaky-wave patch 300 is the right side of the low-frequency leaky-wave metamaterial array 310, then the third number of high-frequency leaky-wave patches 400 are provided on both the left and right sides of the low-frequency leaky-wave metamaterial array 310. Among them, the second number is greater than the third number, and the values of the second number and the third number can be determined according to the actual situation.

[0044] As an example, the low-frequency leaky-wave metamaterial array 310 includes N×N low-frequency leaky-wave patches 300. Along the long side direction of the low-frequency leaky-wave patch 300, 2×P + Q high-frequency leaky-wave patches 400 are distributed around the four sides of the low-frequency leaky-wave metamaterial array 310, where P > Q > N ≥ 2. In the case of adopting this technical solution, the 2×P + Q high-frequency leaky-wave patches 400 distributed on both sides of the low-frequency leaky-wave metamaterial array 310 can obtain the same degree of excitation. And, along the long side direction of the low-frequency leaky-wave patch 300, by distributing more high-frequency leaky-wave patches 400, the radiation aperture in this direction can be increased, thereby improving the gain. Among them, the 2×P + Q high-frequency leaky-wave patches 400 on each side of the low-frequency leaky-wave metamaterial array 310 can be evenly distributed in a circular symmetry, and such a symmetric structure is beneficial to reducing the cross-polarization performance.

[0045] Here, if N is 2, P is 5, and Q is 4. Four low-frequency leaky-wave patches 300 surround the driving patch 100. After the low-frequency leaky-wave patches 300 are excited by the driving patch 100, a total of 14 high-frequency leaky-wave patches 400 on both sides can be excited, four resonant frequencies can be obtained, and while increasing the radiation aperture of the leaky-wave antenna unit to improve the antenna gain, the area of the leaky-wave antenna unit can be minimized as much as possible.

[0046] Further, based on the simulation material model, the theoretical formula of the antenna resonator, and the side length of the low-frequency leaky wave patch 300, the first frequency point f of the leaky wave antenna unit can be calculated. 1 And the second frequency point f 2 , meanwhile, based on the simulation material model, the theoretical formula of the antenna resonator, and the side length of the high-frequency leaky wave patch 400, the third frequency point f of the leaky wave antenna unit can be calculated. 3 And the fourth frequency point f 4 . Among them, the first frequency point f 1 , the second frequency point f 2 , the third frequency point f 3 , and the fourth frequency point f 4 are the resonance frequency points of the leaky wave antenna unit respectively. Here, the side length of the high-frequency leaky wave patch 400 and the side length of the low-frequency leaky wave patch 300 can be obtained by measurement. Here, the shape of the low-frequency leaky wave patch 300 can be rectangular, and the shape of the high-frequency leaky wave patch 400 can be square; the side length of the low-frequency leaky wave patch 300 is the length of the long side of the low-frequency leaky wave patch 300. The longer the side length of the low-frequency leaky wave patch 300, the lower the frequencies of the first frequency point f 1 and the second frequency point f 2 . The longer the side length of the high-frequency leaky wave patch 400, the lower the frequencies of the third frequency point f 3 and the fourth frequency point f 4 .

[0047] As an example, Figure 4 a schematic diagram of the gain, reflection coefficient, and frequency of the leaky wave antenna unit obtained by simulating the leaky wave antenna unit is given. As shown in Figure 4 , through calculation, the first frequency point f 1 and the second frequency point f 2 are 29.6 GHz and 34.8 GHz respectively, and the third frequency point f 3 and the fourth frequency point f 4 are 43.0 GHz and 48.4 GHz respectively. Further, Figure 5 a dispersion diagram mechanism explanation diagram is given, which shows a coordinate diagram corresponding to the phase shift and frequency. The intersection points of the first frequency point f 1 and the frequency-phase shift curve corresponding to the low-frequency leaky wave patch, and the second frequency point f 2 and the frequency-phase shift curve corresponding to the low-frequency leaky wave patch respectively correspond to the resonance frequency points in the TM10 mode and the TM20 mode. The intersection points of the third frequency point f 3 and the frequency-phase shift curve corresponding to the high-frequency leaky wave patch, and the fourth frequency point f 4The intersection points of the frequency-phase shift curves corresponding to the high-frequency leaky patches respectively correspond to the resonant frequencies in the TM30 mode and the TM40 mode. Among them, the TM10 mode and the TM20 mode in which the leaky antenna element operates are excited by the low-frequency leaky patch, and the TM30 mode and the TM40 mode in which the leaky antenna element operates are excited by the high-frequency leaky patch.

[0048] Further, it is possible to determine the impedance bandwidth limit of the leaky antenna element based on the first frequency point f 1 and the fourth frequency point f 4 Here, the bandwidth of the leaky antenna element can be determined through the resonant points corresponding to the phase shifts of the first frequency point f 1 and the fourth frequency point f 4 Further, as Figure 4 shown, it is possible to perform in-band impedance matching on the leaky antenna element based on the second frequency point f 2 and the third frequency point f 3 to ensure impedance matching between the antenna and the feeder, obtain a low and uniform in-band reflection coefficient level, and maximize the power transfer efficiency; here, by making the reflection coefficients corresponding to the second frequency point f 2 and the third frequency point f 3 lower than -10 dB, in-band impedance matching of the leaky antenna element can be achieved.

[0049] In addition, the technical solution of the present application can also increase the impedance bandwidth of the leaky antenna element; specifically, the low-frequency leaky metamaterial array can generate a double-resonant mode with two low-frequency resonant frequencies, the high-frequency leaky metamaterial array can generate a double-resonant mode with two high-frequency resonant frequencies, and the combination of the low-frequency leaky metamaterial array and the high-frequency leaky metamaterial array can generate four resonant frequencies that are close to each other and distinguish between high and low frequencies. The impedance bandwidth of the antenna can be broadened through the four resonant frequencies. Exemplarily, as Figure 4 shown, the resonant frequencies generated by the low-frequency leaky metamaterial array include the first frequency point f 1 and the second frequency point f 2 , the first frequency point f 1 is 29.6 GHz, the second frequency point f 2 is 34.8 GHz, and the low-frequency leaky metamaterial array generates a double-resonant mode with resonant frequencies of f 1 = 29.6 GHz and f 2 = 34.8 GHz. At the same time, the resonant frequencies generated by the high-frequency leaky metamaterial array include the third frequency point f 3 and the fourth frequency point f 4 , the third frequency point f 3 is 43.0 GHz, the fourth frequency point f 4 is 48.4 GHz, and the high-frequency leaky metamaterial array generates resonant frequencies of f3 = 43.0 GHz and f 4 = 48.4 GHz dual-resonant mode. Based on this, four close resonant frequencies expand the impedance bandwidth of the leaky-wave antenna element.

[0050] Furthermore, arranging the high-frequency leaky-wave metamaterial array around the low-frequency leaky-wave metamaterial array can increase the physical aperture of the leaky-wave antenna element, which is beneficial to improving the gain; and both are located on the upper surface of the first dielectric plate 500, which can reduce the number of dielectric plates and lower the profile while achieving resonance. For example, as Figure 4 shown, within the operating frequency band (i.e., within the range of 28.3 GHz - 49.8 GHz), the leaky-wave antenna element achieves a maximum gain of 10.78 dBi at 45 GHz, and the average gain of the leaky-wave antenna element within the operating frequency band is 8.6 dBi.

[0051] For the leaky-wave antenna element provided in this application, all the low-frequency leaky-wave patches are surrounded by multiple high-frequency leaky-wave patches, and the distance between every two adjacent high-frequency leaky-wave patches is equal, so that the multiple high-frequency leaky-wave patches evenly surround the low-frequency leaky-wave patches, making the phase shift constant of the leaky-wave antenna element the same in the electric field direction. Therefore, the antenna bandwidth of the leaky-wave antenna element can be quickly estimated, reducing the bandwidth estimation time required before using the leaky-wave antenna element and improving the usage efficiency of the leaky-wave antenna. At the same time, multiple high-frequency leaky-wave patches are annularly distributed around the periphery of multiple low-frequency leaky-wave patches. In the case of adopting this technical solution, the high-frequency leaky-wave patches can be excited by a rectangular array; moreover, the rectangular patches have regular shapes, which are convenient for processing and design, and are more convenient for obtaining radiators with similar resonant frequencies by controlling the dimensions, thereby obtaining the above four required resonant frequencies, achieving a large impedance bandwidth while ensuring the low profile of the leaky-wave antenna element, and endowing the leaky-wave antenna element with beneficial effects such as low profile, large bandwidth, and high gain. The leaky-wave antenna element can be applied to the 5G communication technology field, improving the applicability of the leaky-wave antenna element.

[0052] In an alternative embodiment, the projections of the geometric centers of the low-frequency leaky-wave metamaterial array, the high-frequency leaky-wave metamaterial array, the metal reflection floor, the driving patch, and the through hole in the direction perpendicular to the metal reflection floor coincide with each other. Specifically, the geometric centers of the low-frequency leaky-wave metamaterial array and the high-frequency leaky-wave metamaterial array coincide. The projection of the geometric center of the low-frequency leaky-wave metamaterial array in the direction perpendicular to the metal reflection floor covers the geometric centers of the metal reflection floor, the driving patch, and the through hole, so that the geometric centers of the low-frequency leaky-wave metamaterial array, the high-frequency leaky-wave metamaterial array, the metal reflection floor, the driving patch, and the through hole are collinear in the up-down direction. The embodiment provided in the present application makes the leaky-wave antenna unit a centrosymmetric structure, which is beneficial to reducing the cross-polarization performance of the leaky-wave antenna unit and improving the signal transmission and reception quality of the leaky-wave antenna unit.

[0053] In an alternative embodiment, as Figure 2 shown, the thicknesses of the first dielectric plate 500 and the third dielectric plate 700 are the same, and the thicknesses of the second dielectric plate 600 and the fourth dielectric plate 900 are the same; wherein, the thicknesses of the first dielectric plate 500 and the third dielectric plate 700 are greater than the thicknesses of the second dielectric plate 600 and the fourth dielectric plate 900. Here, the thicknesses of the first dielectric plate 500 and the third dielectric plate 700 can both be 0.25 mm, and the thicknesses of the second dielectric plate 600 and the fourth dielectric plate 900 can both be 0.04 mm.

[0054] In addition, the first dielectric plate 500 and the third dielectric plate 700 can also be HL972 high-frequency dielectric plates with a thickness of 250 μm, and the second dielectric plate 600 and the fourth dielectric plate 900 can also be GHPL-970 high-frequency dielectric plates with a thickness of 40 μm. In the embodiment provided in the present application, the larger thicknesses of the first dielectric plate and the third dielectric plate are beneficial to improving the impedance bandwidth of the leaky-wave antenna unit, while the smaller thicknesses of the second dielectric plate and the fourth dielectric plate can minimize the profile of the leaky-wave antenna unit and improve the compactness of the leaky-wave antenna unit on the premise of isolating the metal reflection floor and the microstrip feeder.

[0055] In an alternative embodiment, as Figure 3As shown, the shapes of the through hole 810 and the driving patch 100 are respectively rectangular, that is, the shapes of the projections of the through hole 810 and the driving patch 100 along the direction perpendicular to the first dielectric plate 500 are rectangular. Further, the long side of the through hole 810 is perpendicular to the long side of the driving patch 100, and the length of the short side of the driving patch 100 is less than the length of the long side of the through hole 810. Further, the projections of the multiple low-frequency leaky wave patches 300 onto the metal reflection floor along the direction perpendicular to the metal reflection floor can be distributed around the through hole 810, so that the low-frequency leaky wave patches 300 radiate around the through hole 810 as the center. In the embodiment provided by the present application, the width of the driving patch is less than the length of the through hole, so that the projection of the driving patch onto the metal reflection floor along the direction perpendicular to the metal reflection floor intersects and is perpendicular to the through hole, and further the driving patch can fall within the range defined by the through hole. Based on this, the microstrip feeder can couple and feed power to the driving patch through the through hole, improving the signal quality of the wireless signal emitted by the leaky wave antenna unit.

[0056] In an alternative embodiment, as Figure 3 shown, the long side of the through hole 810 is perpendicular to the microstrip feeder 200; specifically, the projection of the microstrip feeder 200 onto the metal reflection floor along the direction perpendicular to the metal reflection floor is perpendicular to the long side of the through hole 810. Further, the open end of the microstrip feeder 200 extends out of the area covered by the through hole 810 on the microstrip feeder 200. Specifically, if the through hole 810 is projected onto the microstrip feeder 200 along the direction perpendicular to the metal reflection floor, the open end of the microstrip feeder 200 extends beyond the area covered by the projection, and the length of the extension beyond the area covered by the projection can be one-quarter wavelength, and this wavelength is the wavelength in free space at a frequency of 39 GHz. In the embodiment provided by the present application, the open end of the microstrip feeder extends out of the left side of the through hole, so as to facilitate the coupling and feeding of the microstrip feeder and the driving patch, enabling the driving patch to obtain greater energy, and further improving the gain of the leaky wave antenna unit.

[0057] Further, the low-frequency leaky wave metamaterial array 310 may include 2×2 low-frequency leaky wave patches 300 with length and width dimensions of 0.6 mm×1.5 mm. The length and width dimensions of the high-frequency leaky wave patches 400 may be 1 mm×1 mm. The distance between two adjacent high-frequency leaky wave patches 400 may be 0.1 mm. The length and width dimensions of the driving patch 100 may be 0.15 mm×1.6 mm; further, the length, width, and height dimensions of the leaky wave antenna unit may be 10 mm×10 mm×0.6 mm, approximately 1.3λ 39GHz ×1.3λ 39GHz ×0.078λ 39GHz where λ 39GHz is the wavelength in free space at a frequency of 39 GHz.

[0058] The leaky-wave antenna unit provided by this application can quickly estimate the antenna bandwidth of the leaky-wave antenna unit, reducing the bandwidth estimation time required before using the leaky-wave antenna unit. At the same time, the driving patch, the low-frequency leaky-wave metamaterial array, and the high-frequency leaky-wave metamaterial array all use the metal reflection floor as the reflection plane. The low-frequency leaky-wave metamaterial array can generate a double-resonance mode with two low-frequency resonance frequencies, and the high-frequency leaky-wave metamaterial array can generate a double-resonance mode with two high-frequency resonance frequencies. By combining the low-frequency leaky-wave metamaterial array and the high-frequency leaky-wave metamaterial array, four resonance frequencies with similar values and distinguishable high and low frequencies are generated, thereby broadening the impedance bandwidth of the leaky-wave antenna unit. In addition, placing the high-frequency leaky-wave metamaterial array around the low-frequency leaky-wave metamaterial array can increase the physical aperture of the leaky-wave antenna unit, which is beneficial to improving the gain of the leaky-wave antenna unit. Moreover, both the low-frequency leaky-wave metamaterial array and the high-frequency leaky-wave metamaterial array are located on the upper surface of the first dielectric plate, which can reduce the number of dielectric plates while achieving resonance, lower the profile of the leaky-wave antenna unit, and enhance the compactness of the leaky-wave antenna unit.

[0059] On the other hand, an embodiment of this application also provides a leaky-wave antenna array, and the leaky-wave antenna array includes the leaky-wave antenna unit as described above. Specifically, as Figure 6 shown, each leaky-wave antenna unit in the leaky-wave antenna array is arranged at intervals to improve the communication effect of the leaky-wave antenna array. Based on the beneficial effects of the above-mentioned leaky-wave antenna unit, the leaky-wave antenna array provided by this application has the beneficial effects of low profile, large bandwidth, and high gain, and can improve the quality of 5G millimeter-wave communication.

[0060] The above serial numbers of this application are only for description and do not represent the advantages or disadvantages of the implementation scenarios. The above disclosure is only several specific implementation scenarios of this application. However, this application is not limited thereto, and any changes that can be thought of by those skilled in the art should fall within the protection scope of this application.

Claims

1. A leaky wave antenna unit, characterized in that: The leaky wave antenna unit includes a driving patch, a microstrip feed line, a plurality of low-frequency leaky wave patches, a plurality of high-frequency leaky wave patches, and a first dielectric plate, a second dielectric plate, a third dielectric plate, a metal reflective floor, and a fourth dielectric plate stacked in sequence from top to bottom; A plurality of the low-frequency leaky wave patches and a plurality of the high-frequency leaky wave patches are arranged on the upper surface of the first dielectric plate, wherein the plurality of the high-frequency leaky wave patches surround the outer sides of the plurality of the low-frequency leaky wave patches, and the distance between each two adjacent high-frequency leaky wave patches is equal; The driving patch is arranged between the first dielectric plate and the second dielectric plate, the metal reflective floor has a through hole penetrating the metal reflective floor, and the projection of the driving patch in a direction perpendicular to the metal reflective floor intersects with the through hole; The microstrip feeder is arranged below the fourth dielectric plate, the connection end of the microstrip feeder is connected to the feeding interface of the host computer, and the projection of the through hole in a direction perpendicular to the metal reflective floor intersects with the microstrip feeder.

2. The leaky wave antenna unit according to claim 1, characterized in that The shape of the low-frequency leaky wave patch is rectangular; A plurality of the low-frequency leaky wave patches form a low-frequency leaky wave metamaterial array on the upper surface of the first dielectric plate, the low-frequency leaky wave metamaterial array includes a first number of low-frequency array rows, and each of the low-frequency array rows includes the first number of low-frequency leaky wave patches; The short sides of each low-frequency leaky wave patch in the low-frequency array row are parallel to each other, and the straight line where the geometric center of each low-frequency leaky wave patch in the low-frequency array row is located is parallel to the long side of each low-frequency leaky wave patch.

3. The leaky wave antenna unit according to claim 2, characterized in that The high-frequency leaky wave patch is in a square shape, and a plurality of the high-frequency leaky wave patches form a high-frequency leaky wave metamaterial array on the upper surface of the first dielectric plate; A second number of the high-frequency leaky wave patches are distributed on each side of the low-frequency leaky wave metamaterial array along the long side direction of the low-frequency leaky wave patches; Along the short side direction of the low-frequency leaky wave patch, a third number of the high-frequency leaky wave patches are distributed on each side of the low-frequency leaky wave metamaterial array.

4. The leaky wave antenna unit according to claim 3, characterized in that The projections of the geometric center of the low-frequency leaky wave metamaterial array, the geometric center of the high-frequency leaky wave metamaterial array, the geometric center of the metal reflective floor, the geometric center of the driving patch, and the geometric center of the through hole in a direction perpendicular to the metal reflective floor coincide with each other.

5. The leaky wave antenna unit according to claim 1, characterized in that The through hole and the driving patch are respectively in the shape of a rectangle; The long side of the through hole is perpendicular to the long side of the driving patch, and the short side of the driving patch is shorter than the long side of the through hole.

6. The leaky wave antenna unit according to claim 5, characterized in that The long side of the through hole is perpendicular to the microstrip feed line.

7. The leaky wave antenna unit according to claim 1, characterized in that The first dielectric plate has the same thickness as the third dielectric plate, and the second dielectric plate has the same thickness as the fourth dielectric plate; The thickness of the first dielectric plate and the third dielectric plate is greater than the thickness of the second dielectric plate and the fourth dielectric plate.

8. The leaky wave antenna unit according to claim 1, characterized in that There is no electrical connection between any two of the low-frequency leaky wave patches, and projections of a plurality of the low-frequency leaky wave patches projected onto the second dielectric plate in a direction perpendicular to the metal reflective floor surround the driving patch.

9. A leaky wave antenna unit according to claim 1, characterized in that: There is no electrical connection between the low-frequency leaky-wave patch and the high-frequency leaky-wave patch.

10. A leaky wave antenna array, characterized in that: The leaky wave antenna array comprises the leaky wave antenna unit according to any one of claims 1 to 9.

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