A high-degree-of-freedom multi-antenna structure with decoupling function

Abstract

This invention discloses a high-degree-of-freedom multi-antenna structure with decoupling function, including a rectangular metal patch array. The rectangular metal patch array is formed by m*n rectangular metal patches of the same size, evenly distributed in m rows and n columns. Each row and each column is connected by a switch between every two adjacent rectangular metal patches. In the initial state, all switches are in the off state. The number of antennas included in the high-degree-of-freedom multi-antenna structure is denoted as N. The N antennas are formed by selecting N columns of rectangular metal patches from the rectangular metal patch array as N antenna columns. The decoupling structure is formed from the other columns of rectangular metal patches in the rectangular metal patch array besides the N antenna columns. The advantage is that it has a high degree of freedom in design and optimization, and can be flexibly expanded.

Description

Technical Field

[0001] This invention relates to multi-antenna structures, and more particularly to a high-degree-of-freedom multi-antenna structure with decoupling functionality. Background Technology

[0002] With increasingly scarce spectrum resources and ever-growing communication demands, traditional fixed-structure antennas, while performing well in specific applications, have significant limitations in adapting to changing communication environments and frequency diversity, thus necessitating greater antenna flexibility. Meanwhile, with the proliferation of mobile communication standards and technological evolution, the importance of MIMO (Multi-Input Multiple-Output) systems in the communications field is becoming increasingly prominent. However, the application of MIMO systems faces coupling problems caused by the close-range arrangement of their internal antennas. Currently, MIMO systems need to meet the requirements of different application frequency bands, including 2G / 3G / 4G, 5G, Wi-Fi, and Bluetooth. Therefore, MIMO systems require not only high flexibility but also effective decoupling structures to reduce the coupling effects between their internal antennas across multiple frequency bands.

[0003] The paper "Fatima Amin, Rashid Saleem, Tayyab Shabbir, et al. A Compact Quad-Element UWB-MIMO Antenna System with Parasitic Decoupling Mechanism[J]. Applied Sciences, 2019, 9(11): 2371" introduces a MIMO multi-antenna system, which consists of multiple antenna structures and multiple decoupling structures. Each antenna structure is a semi-elliptical quad-element ultra-wideband multiple-input multiple-output structure, and each decoupling structure is implemented using horizontal parasitic decoupling strips and dumbbell-shaped stub structures. In this MIMO multi-antenna system, the antenna structure is fixed. When it is necessary to add or change the operating frequency band, the antenna structure cannot be reconstructed; it must be redesigned. Furthermore, its decoupling structure is also fixed and immutable. Once the antenna structure changes, its decoupling structure also fails and needs to be redesigned. Therefore, the design and optimization freedom of the above MIMO multi-antenna system is very low, and it cannot achieve flexible expansion. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a high degree of freedom multi-antenna structure with decoupling function that has a high degree of design and optimization freedom and can be flexibly expanded.

[0005] The technical solution adopted by this invention to solve the above-mentioned technical problems is as follows: a high-degree-of-freedom multi-antenna structure with decoupling function, comprising a rectangular metal patch array, wherein the rectangular metal patch array is formed by m*n rectangular metal patches of the same size evenly distributed in m rows and n columns, where * represents the multiplication operator, m and n are both integers, and m>5, n>4. Each row and each column of adjacent rectangular metal patches are connected by a switch. In the initial state, all switches are in the open state. The number of antennas included in the high-degree-of-freedom multi-antenna structure is denoted as . N, where N is an integer greater than or equal to 2, is selected from the rectangular metal patch array as N antenna building columns. From each antenna building column, the required number of rectangular metal patches are selected, and the switches between any two adjacent rectangular metal patches in the selected required number of rectangular metal patches are closed to build an antenna, thereby forming N antennas. After forming N antennas, a decoupling structure is built from the other columns of rectangular metal patches in the rectangular metal patch array besides the N antenna building columns. This decoupling structure ensures that the mutual admittance of any two antennas at each operating frequency meets the design requirements.

[0006] The high-degree-of-freedom multi-antenna structure with decoupling function further includes a dielectric substrate, a first metal ground, a second metal ground, and multiple metallized vias. The dielectric substrate has a cuboid structure, with its length direction defined as the front-back direction, its width direction as the left-right direction, and its height direction as the up-down direction. The first metal ground has a rectangular structure, with its length direction along the left-right direction and its width direction along the front-back direction. The first metal ground is attached to the upper surface of the dielectric substrate, with its front end flush with the front face of the dielectric substrate, its left end flush with the left end face of the dielectric substrate, and its right end flush with the right end face of the dielectric substrate. The first metal ground plane is flush with the surface of the dielectric substrate. Its width is less than the length of the dielectric substrate. The second metal ground plane has a rectangular structure, with its length along the left-right direction and its width along the front-back direction. The second metal ground plane is attached to the lower surface of the dielectric substrate. Its front end, left end, and right end are flush with the left and right ends of the dielectric substrate. The width of the second metal ground plane is greater than the width of the first metal ground plane. Multiple metallized vias penetrate from top to bottom through the first metal ground plane, the dielectric substrate, and the second metal ground plane, connecting the first metal ground plane and the dielectric substrate. The second metal ground connection makes the first metal ground and the second metal ground an equipotential body; the plane that makes the dielectric substrate symmetrical from left to right is called the first symmetry plane; m*n rectangular metal patches are attached to the upper surface of the dielectric substrate, the length direction of each rectangular metal patch is along the left-right direction, and the width direction is along the front-back direction; the spacing between two adjacent rectangular metal patches in each row and the spacing between two rectangular metal patches in each column are equal, denoted as d; the front ends of each row of rectangular metal patches are located on the same straight line, and this straight line is parallel to the front end face of the dielectric substrate; the left ends of each column of rectangular metal patches are located on the same straight line, and this straight line is parallel to the left end face of the dielectric substrate; the m rows of rectangular metal patches are... The rectangular metal patches, from back to front, are designated as the first row to the m-th row. Similarly, the n columns of rectangular metal patches, from left to right, are designated as the first column to the n-th column. The straight line containing the rear end of the first row of rectangular metal patches is located in front of the rear end of the dielectric substrate. The straight line containing the front end of the m-th row of rectangular metal patches is located behind the rear end of the first metal ground plane, with a distance d between them. The straight line containing the left end of the first column of rectangular metal patches is located to the right of the plane containing the left end face of the dielectric substrate; the straight line containing the right end of the n-th column of rectangular metal patches is located to the left of the plane containing the right end face of the dielectric substrate. The array of rectangular metal patches is symmetrical about the first symmetry plane.

[0007] Each antenna is constructed as follows: First, select a column of rectangular metal patches from the rectangular metal patch array. Starting from the m-th row of the rectangular metal patches in that column, select the corresponding number of rectangular metal patches. Then, close the switches between any two adjacent rectangular metal patches in all the selected rectangular metal patches. At this point, one antenna is constructed. Any two antennas can be constructed from different columns of rectangular metal patches. The N antennas are evenly spaced, and there are at least 3 columns of rectangular metal patches between any two adjacent antennas. If an antenna is to operate at a single frequency, and the distance between the front end of the first row of rectangular metal patches and the rear end of the m-th row of rectangular metal patches is greater than half the wavelength of its operating frequency, then the distance between the front end of the first row of rectangular metal patches and the rear end of the last row of rectangular metal patches in that antenna is... If an antenna is to operate at multiple frequencies, and the distance between the front end of the first row of rectangular metal patches and the rear end of the m-th row of rectangular metal patches is less than or equal to half the wavelength of its operating frequency, then the antenna selects an entire column of rectangular metal patches. If the distance between the front end of the first row of rectangular metal patches and the rear end of the m-th row of rectangular metal patches is greater than the average of half the wavelength of its multiple operating frequencies, then the distance between the front end of the first row of rectangular metal patches and the rear end of the last row of rectangular metal patches is closest to the average of half the wavelength of its multiple operating frequencies. If the distance between the front end of the first row of rectangular metal patches and the rear end of the m-th row of rectangular metal patches is less than or equal to the average of half the wavelength of its multiple operating frequencies, then the antenna selects an entire column of rectangular metal patches.

[0008] Let M be the number of operating frequencies of the N antennas. The N antennas are named from left to right as antenna 1 to antenna N. The j-th antenna needs to be constructed including K... j The decoupling unit of each decoupling branch, K jLet j be an integer greater than or equal to M(N-1), where j = 1, 2, 3, ..., N; the decoupling units of N antennas constitute the decoupling structure, and the number of decoupling branches included in the decoupling structure is denoted as S, where S is an integer greater than or equal to MN(N-1); for the i-th antenna, i = 2, 3, ..., N-1, the construction area of ​​its decoupling branch is between the leftmost decoupling branches of this antenna and the (i+1)-th antenna, or between the rightmost decoupling branches of this antenna and the (i-1)-th antenna; for the 1st antenna, if the antenna is constructed at the first column of rectangular metal patches, The decoupling branch's construction area is located between the leftmost decoupling branches among all decoupling branches of this antenna and the second antenna. If this antenna is not constructed at the first column of rectangular metal patches, then the decoupling branch's construction area is located between the leftmost decoupling branches among all decoupling branches of this antenna and the second antenna, or to the left of this antenna. For the Nth antenna, if this antenna is constructed at the nth column of rectangular metal patches, then the decoupling branch's construction area is located between the rightmost decoupling branches among all decoupling branches of this antenna and the (N-1)th antenna. If this antenna is not constructed at the nth column of rectangular metal patches, then the decoupling branch's construction area is located between the rightmost decoupling branches among all decoupling branches of this antenna and the (N-1)th antenna. The construction area is located between the rightmost decoupling branches of the antenna and the (N-1)th antenna, or to the right of the antenna. The decoupling unit of any one of the N antennas is constructed as follows: Let 'a' be the number of rectangular metal patches used to construct the antenna. Within the construction area of ​​the antenna, select any column of rectangular metal patches that has no other decoupling branches. Starting from the rectangular metal patch in row b of that column, select at least 3 rectangular metal patches forward. Then, or select all the selected rectangular metal patches except for those in row b and row b+1. Except for the switches between any two adjacent rectangular metal patches, all other switches between any two adjacent rectangular metal patches are closed, thus completing the construction of a decoupling branch. This decoupling branch is called a parasitic decoupling branch. Alternatively, if all the selected rectangular metal patches are closed, all the switches between any two adjacent rectangular metal patches are closed, thus completing the construction of a decoupling branch. This decoupling branch is called a self-decoupling branch. Where a is odd, then either b = ma / 2 + 1 / 2, or b = ma / 2 - 1 / 2, or b = ma / 2 + 3 / 2. If a is even, then either b = ma / 2 + 1, or b = ma / 2, or b = ma / 2 + 2.After all decoupling branches of the antenna are built, connect them as follows: Let g be the column number of the antenna in the rectangular metal patch array, meaning the antenna is built at the g-th column of the rectangular metal patch array. Let k be the column number of the leftmost decoupling branch of the antenna in the rectangular metal patch array, meaning the leftmost decoupling branch is built at the k-th column of the rectangular metal patch array. Let h be the column number of the rightmost decoupling branch of the antenna in the rectangular metal patch array. The antenna is constructed at the rectangular metal patch. If the decoupling branches of the antenna are distributed on its left and right sides, then in the b-th row of the rectangular metal patch array, the switches between every two adjacent rectangular metal patches in the h-k+1 rectangular metal patches located in the k-th to h-th columns are closed. If the decoupling branches of the antenna are only distributed on its left side, then in the b-th row of the rectangular metal patch array, the switches between every two adjacent rectangular metal patches in the g-k+1 rectangular metal patches located in the k-th to h-th columns are closed. If the decoupling branches of the antenna are only distributed on its right side, then in the b-th row of the rectangular metal patch array, the switches between every two adjacent rectangular metal patches in the g-k+1 rectangular metal patches located in the g-th to h-th columns are closed. In the h-g+1 rectangular metal patches, the switches between every two adjacent rectangular metal patches are closed, at which point the connection of all decoupling branches of the antenna is completed. After the connection of all decoupling branches of the antenna is completed, in the antenna construction area, at least one rectangular metal patch not used to construct its decoupling branch is selected from the rectangular metal patches in the m-th row to the (m-2)-th row of the rectangular metal patch array as the grounding metal patch of the antenna. Each grounding metal patch of the antenna is provided with a metallized via that runs from top to bottom through the grounding metal patch, the dielectric substrate, and the second metal ground. The rectangular metal patch in the first row of each decoupling branch of the antenna is selected as the grounding metal patch. Choose a connection path that connects the antenna to the grounding metal patch that is closest to it in a straight line. Close the switch between any two adjacent rectangular metal patches on the connection path to connect each decoupling branch of the antenna to the second metal ground. When there are multiple grounding metal patches that are closest in a straight line, arbitrarily select one of them. The connection path is selected based on the number of rectangular metal patches used, and no rectangular metal patch on this connection path can appear on the connection path between other decoupling branches of the antenna and the grounding metal patch. When there are multiple connection paths that meet the condition of using the fewest rectangular metal patches, arbitrarily select one of them.Determine whether the switches between each grounding metal patch and its adjacent rectangular metal patches (front, back, left, and right) are closed. If a switch is closed, connect a load in parallel across the two ends of that switch. At this point, the decoupling unit of the antenna is complete. When the decoupling units of N antennas are all completed, the decoupling structure is formed. Since each decoupling branch is connected to a grounding metal patch via a connection path, and the rectangular metal patches in the connection path between any decoupling branch and the grounding metal patch are not repeated, there are a total of S decoupling branches. Each decoupling branch has a different connection path to the grounding metal patch and includes a load, so there are a total of S loads. The selection of S loads and their parameters ensures that the mutual admittance of any two antennas at each operating frequency meets the design requirements.

[0009] Each load is selected from either a capacitor or an inductor. When the load is a capacitor, the load parameter is the capacitance value; when the load is an inductor, the load parameter is the inductance value. Any two loads and their selected load parameters can be the same or different.

[0010] Compared with the prior art, the advantage of this invention lies in setting up a rectangular metal patch array formed by m*n rectangular metal patches of the same size, evenly distributed in m rows and n columns, where * represents the multiplication operator, m and n are both integers, and m>5, n>4. Each row and each column of adjacent rectangular metal patches is connected by a switch. Initially, all switches are in the off state. The number of antennas included in the high-degree-of-freedom multi-antenna structure is denoted as N, where N is an integer greater than or equal to 2. That is, the high-degree-of-freedom multi-antenna structure needs to include N antennas. At this time, N columns of rectangular metal patches are selected from the rectangular metal patch array as N antennas. The antenna array is constructed by selecting a required number of rectangular metal patches from each array and closing the switch between any two adjacent rectangular metal patches to construct an antenna, thereby forming N antennas. After forming N antennas, a decoupling structure is constructed from the rectangular metal patches in the array other than the N antenna arrays. This decoupling structure ensures that the mutual admittance of any two antennas at each operating frequency meets the design requirements, thus achieving decoupling of the N antennas. Therefore, the design and optimization of this invention can be achieved through the rectangular metal patch array, with a high degree of freedom in design and optimization, and the ability to be flexibly expanded. Attached Figure Description

[0011] Figure 1 This is a verification example of the original antenna structure of a high-degree-of-freedom multi-antenna structure with decoupling function according to the present invention;

[0012] Figure 2(a) shows a high-degree-of-freedom multi-antenna structure with decoupling function according to the present invention. Figure 1A complete schematic diagram of a set of examples with decoupling at a single frequency point of 3.5GHz is shown when verifying the original antenna structure of the example.

[0013] Figure 2(b) shows a high-degree-of-freedom multi-antenna structure with decoupling function according to the present invention. Figure 1 A simplified schematic diagram of a set of examples decoupled at a single frequency point of 3.5GHz when verifying the original antenna structure of the example;

[0014] Figure 3 for Figure 1 The diagram shown is a verification example of the original antenna structure of a high degree-of-freedom multi-antenna structure with decoupling function according to the present invention.

[0015] Figure 4 This is a schematic diagram of the S-parameters of a high-degree-of-freedom multi-antenna structure with decoupling function of the present invention, showing the decoupling structure built at a single frequency point of 3.5GHz. Detailed Implementation

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0017] Example 1: As Figure 1 As shown, a high-degree-of-freedom multi-antenna structure with decoupling function includes a rectangular metal patch array 1. The rectangular metal patch array 1 is formed by m*n rectangular metal patches of the same size, evenly distributed in m rows and n columns, where * represents the multiplication operator, m and n are both integers, and m>5, n>4. Every two adjacent rectangular metal patches in each row and every two adjacent rectangular metal patches in each column are connected by a switch. In the initial state, all switches are in the open state. The number of antennas included in the high-degree-of-freedom multi-antenna structure is denoted as N, where N is greater than or equal to 2. An integer is used to select N columns of rectangular metal patches from the rectangular metal patch array 1 as N antenna building columns. From each antenna building column, the required number of rectangular metal patches are selected, and the switches between any two adjacent rectangular metal patches in the selected required number of rectangular metal patches are closed to build an antenna, thereby forming N antennas. After forming N antennas, a decoupling structure is built from the other columns of rectangular metal patches in the rectangular metal patch array 1, excluding the N antenna building columns. This decoupling structure ensures that the mutual admittance of any two antennas at each operating frequency meets the design requirements.

[0018] In this embodiment, by adding an external bias circuit to control the on / off state of each switch, the connection and disconnection between the two rectangular metal patches connected to the switch can be realized. The design and optimization of the high degree of freedom multi-antenna structure with decoupling function of the present invention can be realized through the rectangular metal patch array 1. The design and optimization have a high degree of freedom and can be flexibly expanded.

[0019] Example 2: This example is basically the same as Example 1, except that: In this example, a high-degree-of-freedom multi-antenna structure with decoupling function further includes a dielectric substrate 2, a first metal ground 3, a second metal ground 4, and multiple metallized vias 5. The dielectric substrate 2 has a cuboid structure, with its length direction as the front-back direction, its width direction as the left-right direction, and its height direction as the up-down direction. The first metal ground 3 has a rectangular structure, with its length direction along the left-right direction and its width direction along the front-back direction. The first metal ground 3 is attached to the upper surface of the dielectric substrate 2, with its front end flush with the front face of the dielectric substrate 2, and its left end flush with the left face of the dielectric substrate 2. The first metal ground 3 is flush with the right end face of the dielectric substrate 2. The width of the first metal ground 3 is less than the length of the dielectric substrate 2. The second metal ground 4 has a rectangular structure, with its length along the left-right direction and its width along the front-back direction. The second metal ground 4 is attached to the lower surface of the dielectric substrate 2. The front end of the second metal ground 4 is flush with the front end face of the dielectric substrate 2. The left end of the second metal ground 4 is flush with the left end face of the dielectric substrate 2. The right end of the second metal ground 4 is flush with the right end face of the dielectric substrate 2. The width of the second metal ground 4 is greater than the width of the first metal ground 3. Multiple metallized through-holes 5 penetrate from top to bottom through the first metal ground 3, the dielectric substrate 2, and the second metal ground 4, connecting the first metal ground 3 and the second metal ground 4. Two metal grounds 4 are connected, making the first metal ground 3 and the second metal ground 4 form an equipotential body; the plane that makes the dielectric substrate 2 symmetrical from left to right is called the first symmetry plane. m*n rectangular metal patches are attached to the upper surface of the dielectric substrate 2. The length direction of each rectangular metal patch is along the left-right direction, and the width direction is along the front-back direction. The spacing between two adjacent rectangular metal patches in each row and the spacing between two rectangular metal patches in each column are equal, and this spacing is denoted as d. The front ends of the rectangular metal patches in each row are located on the same straight line, and this straight line is parallel to the front end face of the dielectric substrate 2. The left ends of the rectangular metal patches in each column are located on the same straight line, and this straight line is parallel to the left end face of the dielectric substrate 2. The m rows of rectangular metal patches are then connected. The metal patches are sequentially named from back to front as the first row of rectangular metal patches to the m-th row of rectangular metal patches. The n columns of rectangular metal patches are sequentially named from left to right as the first column of rectangular metal patches to the n-th column of rectangular metal patches. The straight line containing the rear end of the first row of rectangular metal patches is located in front of the rear end of the dielectric substrate 2. The straight line containing the front end of the m-th row of rectangular metal patches is located behind the rear end of the first metal ground 3, and the distance between them is d. The straight line containing the left end of the first column of rectangular metal patches is located to the right of the plane containing the left end face of the dielectric substrate 2. The straight line containing the right end of the n-th column of rectangular metal patches is located to the left of the plane containing the right end face of the dielectric substrate 2. The rectangular metal patch array 1 is symmetrical about the first symmetry plane.

[0020] In this embodiment, each antenna is constructed as follows: First, a column of rectangular metal patches in the rectangular metal patch array 1 is selected. Starting from the m-th row of the rectangular metal patches in that column, a corresponding number of rectangular metal patches are selected backwards. Then, the switches between any two adjacent rectangular metal patches in all the selected rectangular metal patches are closed. At this point, one antenna is constructed. Any two antennas select rectangular metal patches from different columns. N antennas are evenly spaced, and there are at least 3 columns of rectangular metal patches between any two adjacent antennas. If an antenna is to operate at a single frequency, and the distance between the front end of the first row of rectangular metal patches and the rear end of the m-th row of rectangular metal patches is greater than half the wavelength of its operating frequency, then the distance between the front end of the first row of rectangular metal patches and the rear end of the last row of rectangular metal patches in that antenna is... If an antenna is to operate at multiple frequencies, and the distance between the front end of the first row of rectangular metal patches and the rear end of the m-th row of rectangular metal patches is less than or equal to half the wavelength of its operating frequency, then the antenna selects an entire column of rectangular metal patches. If the distance between the front end of the first row of rectangular metal patches and the rear end of the m-th row of rectangular metal patches is greater than the average of half the wavelength of its multiple operating frequencies, then the antenna selects an entire column of rectangular metal patches when the distance between the front end of the first row of rectangular metal patches and the rear end of the last row is closest to the average of half the wavelength of its multiple operating frequencies.

[0021] In this embodiment, the number of operating frequency points of the N antennas is denoted as M. The N antennas are sequentially named from left to right as antenna 1 to antenna N. Antenna j requires the construction of K antennas. j The decoupling unit of each decoupling branch, K jLet j be an integer greater than or equal to M(N-1), where j = 1, 2, 3, ..., N; the decoupling units of N antennas constitute a decoupling structure, and the number of decoupling branches included in the decoupling structure is denoted as S, where S is an integer greater than or equal to MN(N-1); for the i-th antenna, i = 2, 3, ..., N-1, the construction area of ​​its decoupling branch is between the leftmost decoupling branches of this antenna and the (i+1)-th antenna, or between the rightmost decoupling branches of this antenna and the (i-1)-th antenna; for the 1st antenna, if the antenna is constructed at the rectangular metal patch in the 1st column, then its decoupling branch... The area where a branch is installed is between the leftmost decoupling branches of the antenna and the second antenna. If the antenna is not installed at the first column of rectangular metal patches, then the area where its decoupling branch is installed is between the leftmost decoupling branches of the antenna and the second antenna, or to the left of the antenna. For the Nth antenna, if the antenna is installed at the nth column of rectangular metal patches, then the area where its decoupling branch is installed is between the rightmost decoupling branches of the antenna and the (N-1)th antenna. If the antenna is not installed at the nth column of rectangular metal patches, then the area where its decoupling branch is installed is between the rightmost decoupling branches of the antenna and the (N-1)th antenna. The region is located between the rightmost decoupling branches of the antenna and the (N-1)th antenna, or to the right of the antenna. The decoupling unit of any one of the N antennas is constructed as follows: Let 'a' be the number of rectangular metal patches used to construct the antenna. Within the construction area of ​​the antenna, select any column of rectangular metal patches that has no other decoupling branches. Starting from the rectangular metal patch in row b of that column, select at least 3 rectangular metal patches forward. Then, or select all the selected rectangular metal patches except those in row b and row b+1. Except for the switch between any two adjacent rectangular metal patches, all other switches between any two adjacent rectangular metal patches are closed, and a decoupling branch is completed. This decoupling branch is called a parasitic decoupling branch. Alternatively, if all the selected rectangular metal patches are closed, all other switches between any two adjacent rectangular metal patches are closed, and a decoupling branch is completed. This decoupling branch is called a self-decoupling branch. If a is odd, then either b = ma / 2 + 1 / 2, or b = ma / 2 - 1 / 2, or b = ma / 2 + 3 / 2. If a is even, then either b = ma / 2 + 1, or b = ma / 2, or b = ma / 2 + 2.After all decoupling branches of the antenna are constructed, connect them as follows: Let g be the column number of the antenna in the rectangular metal patch array 1, meaning the antenna is constructed at the g-th column of the rectangular metal patch array 1. Let k be the column number of the leftmost decoupling branch of the antenna in the rectangular metal patch array 1, meaning the leftmost decoupling branch is constructed at the k-th column of the rectangular metal patch array 1. Let h be the column number of the rightmost decoupling branch of the antenna in the rectangular metal patch array 1, meaning the rightmost decoupling branch is constructed at the h-th column of the rectangular metal patch array 1. For setup, if the decoupling branches of the antenna are distributed on its left and right sides, then in the rectangular metal patch array 1, in the row b, the h-k+1 rectangular metal patches located in columns k to h, close the switches between every two adjacent rectangular metal patches. If the decoupling branches of the antenna are only distributed on its left side, then in the rectangular metal patch array 1, in the row b, the g-k+1 rectangular metal patches located in columns k to h, close the switches between every two adjacent rectangular metal patches. If the decoupling branches of the antenna are only distributed on its right side, then in the rectangular metal patch array 1, in the row b, the h-g+1 rectangular metal patches located in columns g to h, close the switches between every two adjacent rectangular metal patches. In the rectangular metal patches, the switches between every two adjacent rectangular metal patches are closed, at which point the connection of all decoupling branches of the antenna is completed. After the connection of all decoupling branches of the antenna is completed, in the antenna construction area, at least one rectangular metal patch not used to construct its decoupling branch is selected from the rectangular metal patches in the m-th row to the (m-2)-th row of the rectangular metal patch array 1 as the grounding metal patch of the antenna. Each grounding metal patch of the antenna is provided with a metallized via 5 that runs from top to bottom through the grounding metal patch, the dielectric substrate 2, and the second metal ground 4. The rectangular metal patch in the first row of each decoupling branch of the antenna is selected to be able to construct its decoupling branch. A connection path is connected to the grounding metal patch that is closest to it in a straight line. The switch between any two adjacent rectangular metal patches on the connection path is closed, thereby realizing the connection between each decoupling branch of the antenna and the second metal ground 4. When there are multiple grounding metal patches that are closest in a straight line, one of the grounding metal patches is arbitrarily selected. The connection path is selected to use the fewest rectangular metal patches. And no rectangular metal patch on the connection path can appear on the connection path between other decoupling branches of the antenna and the grounding metal patch. When there are multiple connection paths that meet the condition of using the fewest rectangular metal patches, one is arbitrarily selected from them.Determine whether the switches between each grounding metal patch and its adjacent rectangular metal patches (front, back, left, and right) are closed. If a switch is closed, connect a load in parallel across the two ends of that switch. At this point, the decoupling unit of the antenna is complete. When all N antenna decoupling units are completed, a decoupling structure is formed. Since each decoupling branch is connected to a grounding metal patch via a connection path, and the rectangular metal patches in the connection path between any decoupling branch and the grounding metal patch are not repeated, there are a total of S decoupling branches. Each decoupling branch has a different connection path to the grounding metal patch and includes a load, therefore there are a total of S loads. The selection of these S loads and their parameters ensures that the mutual admittance of any two antennas at each operating frequency meets the design requirements.

[0022] In this embodiment, each load is selected from either a capacitor or an inductor. When the load is a capacitor, the load parameter is the capacitance value; when the load is an inductor, the load parameter is the inductance value. The selection of any two loads and their load parameters can be the same or different.

[0023] The load parameters for each load can be obtained based on the load parameter determination method disclosed in Chinese Patent CN114759345A, entitled "A Decoupling Structure for Tunable Multi-Frequency Points Between Two Antennas Based on Parasites". Since the load parameter determination method disclosed in "A Decoupling Structure for Tunable Multi-Frequency Points Between Two Antennas Based on Parasites" applies to two antennas, while the load parameters in the high-degree-of-freedom multi-antenna structure with decoupling function of this invention apply to N antennas, decoupling is required between any two antennas. Therefore, when using the load parameter determination method disclosed in "A Decoupling Structure for Tunable Multi-Frequency Points Between Two Antennas Based on Parasites" to determine the load parameters in the high-degree-of-freedom multi-antenna structure with decoupling function of this invention, steps (1)-(11) are first performed once for every two antennas to obtain the mutual admittance Y1'2(f) at the e-th frequency point between every two antennas. e The formula is given by e, where e = 1, 2, ..., M; then, the following operations are performed on any two antennas out of the N antennas:

[0024] Select two antennas and set the intermediate parameter D(f) e Let D(f) e )={Re{Y1'2(f e )}} 2 +{Im{Y1'2(f e )}} 2 , where Re{Y1'2(f e )} is Y1'2(f e The real part of ) is Im{Y1'2(f e )} is Y1'2(f eThe imaginary part of ); the reactance XL of the u-th load at the first frequency point. u (f1) Randomly assign values ​​within the range (c1, c2), where u = 1, 2…S, and the range of c1 is (-1 × 10⁻⁶). 6 -1×10 4 The range of values ​​for c2 is (1×10). -4 1×10 8 If the reactance of the u-th load is positive at this time, then the load is determined to be an inductor, and the reactance of the u-th load at the e-th frequency point is obtained. If the reactance of the u-th load is negative at this point, then the load is determined to be a capacitor, and the reactance of the u-th load at the e-th frequency point is obtained. At this point, the mutual admittance formulas of the two antennas obtained in steps (1)-(11) are used to obtain Y1'2(f e ), take Y1'2(f e The real and imaginary parts of ) are used to obtain the intermediate parameter D(f). e At this point, we obtain D(f1) to D(f) between the two antennas. M ).

[0025] After performing the above operation on every two antennas out of N antennas, the operation is repeated N(N-1) times. Each time, a set of D(f1) to D(f2) is obtained. M Therefore, a total of N(N-1) sets of D(f1) to D(f) are obtained. M ), that is, N(N-1)M intermediate parameters. Construct a set D for storing data, and transfer the currently obtained N(N-1) sets D(f1) to D(f2)... M The intermediate parameter with the largest value among these N(N-1)M intermediate parameters is stored as a data point in set D. Then, the reactance XL of the u-th load at the first frequency point is calculated again. u (f1) Randomly assign values ​​within the assignment range (c1, c2), and store a data in set D again using the same method as above, until Q data are stored in set D, where Q is the number of optimizations and is an integer greater than or equal to 500; at this point, take the data with the smallest value in set D and record it as minD. The reactance values ​​of the S loads at the frequency point corresponding to minD are used as the reactance values ​​corresponding to the final selected loads.

[0026] After completing the above steps, finally execute step (13) to complete the determination of each load parameter.

[0027] To verify the performance of the high-degree-of-freedom multi-antenna structure with decoupling function of the present invention, let m = 15, n = 11, the rectangular metal patches are square patches with a length and width of l, l = 1.5 mm, the spacing between two adjacent rectangular metal patches is d = 0.3 mm, and N = 2. That is, the high-degree-of-freedom multi-antenna structure with decoupling function of the present invention includes two antennas, which are referred to as antenna 1 and antenna 2 from left to right. Antenna 1 is constructed by selecting rectangular metal patches located in rows 1 to 15 of the 4th column of rectangular metal patches, and then closing the switches between any two adjacent rectangular metal patches. Antenna 2 is constructed by selecting rectangular metal patches located in rows 4 to 15 of the 8th column of rectangular metal patches, and then closing the switches between any two adjacent rectangular metal patches. Antenna 1 and Antenna 2 are a pair of monopole antennas, used as verification examples of a high-degree-of-freedom multi-antenna structure with decoupling function according to the present invention. The original antenna structure was used to verify the decoupling performance of the antenna structure in single-frequency cases at six frequency points: 3.0 GHz, 3.5 GHz, 4.0 GHz, 4.5 GHz, 5.0 GHz, and 5.5 GHz. The S-parameters of the antenna structure are as follows: Figure 3 As shown. Analysis Figure 3 It can be seen that the transmission coefficients at the frequency points of 3.0GHz, 3.5GHz, 4.0GHz, 4.5GHz, 5.0GHz, and 5.5GHz are... The values ​​are all greater than -10dB, indicating that the coupling between the two antennas is quite significant. Therefore, this verification example is used to verify the decoupling performance of dual antennas in a single-frequency scenario.

[0028] To achieve decoupling of antenna 1 and antenna 2, a decoupling structure is constructed for antenna 1 and antenna 2, as shown in Figure 2(a) and Figure 2(b). k1, k2, k3, and k4 are switches. For antenna 1, the rectangular metal patches located in rows 9 to 14 of the first column are selected, and the switches between any two adjacent rectangular metal patches are closed, thus completing the construction of decoupling branch 6, which is a self-decoupling branch. The rectangular metal patches located in rows 9 to 13 of the third column are selected, and the switches between any two adjacent rectangular metal patches are closed except for the switch k2 between the rectangular metal patches in rows 9 and 10, thus completing the construction of decoupling branch 7, which is a parasitic decoupling branch. For antenna 2, select the rectangular metal patches located in rows 11 to 14 of the 11th column. Close the switches between any two adjacent rectangular metal patches, thus completing decoupling branch 8, which is a self-decoupling branch. Select the rectangular metal patches located in rows 11 to 13 of the 9th column. Except for switch k3 between the rectangular metal patches in rows 11 and 12, close the switches between any two adjacent rectangular metal patches, thus completing decoupling branch 9, which is a parasitic decoupling branch. Therefore, after building decoupling branches for antennas 1 and 2, k1 and k4 are closed, and k2 and k3 are open.

[0029] The required decoupling frequency is 3.5GHz. The calculated load parameters for each decoupling branch are Y. L(1) =7.2nH, Y L(2) =3.7nH, Y L(3) =1.6nH, Y L(4) =7.2nH.

[0030] The S-parameter diagram of antenna 1 and antenna 2 after decoupling at a single frequency of 3.5 GHz is shown below. Figure 4 As shown. Analysis Figure 4 It can be seen that the actual simulation yields a decoupling frequency of f1 = 3.49 GHz. This decoupling frequency offset is within the normal frequency offset range. At this point, the transmission coefficients of antenna 1 and antenna 2 after decoupling are... Less than -10dB, and compared to Figure 3 The S-parameters of the original antenna structure, consisting of antennas 1 and 2, shown in the verification example, have been improved by more than 25dB in reflection coefficient, demonstrating a significant decoupling effect.

[0031] In summary, the design and optimization of the high-degree-of-freedom multi-antenna structure with decoupling function of the present invention can both be achieved through a rectangular metal patch array, with a high degree of freedom in design and optimization, and the ability to be flexibly expanded.

Claims

1. A high-degree-of-freedom multi-antenna structure with decoupling function, characterized in that... The system includes a rectangular metal patch array, which is formed by m*n rectangular metal patches of the same size evenly spaced in m rows and n columns, where * represents the multiplication operator, m and n are integers, and m>5, n>4. Each row and each column is connected by a switch between every two adjacent rectangular metal patches. Initially, all switches are in the off state. The number of antennas in the high-degree-of-freedom multi-antenna structure is denoted as N, where N is an integer greater than or equal to 2. N columns of rectangular metal patches are selected from the rectangular metal patch array as N antenna construction columns. From each antenna construction column, the required number of rectangular metal patches are selected, and the switches between any two adjacent rectangular metal patches in the selected required number of rectangular metal patches are closed to construct an antenna, thereby forming N antennas. After forming N antennas, a decoupling structure is constructed from the other columns of rectangular metal patches in the rectangular metal patch array, excluding the N antenna construction columns. This decoupling structure ensures that the mutual admittance of any two antennas at each operating frequency meets the design requirements.

2. The high-degree-of-freedom multi-antenna structure with decoupling function according to claim 1, characterized in that... It also includes a dielectric substrate, a first metal ground, a second metal ground, and multiple metallized vias. The dielectric substrate has a cuboid structure, with its length direction defined as the front-to-back direction, its width direction as the left-to-right direction, and its height direction as the up-to-down direction. The first metal ground has a rectangular structure, with its length direction along the left-to-right direction and its width direction along the front-to-back direction. The first metal ground is attached to the upper surface of the dielectric substrate, with its front end flush with the front face of the dielectric substrate and its left end flush with the left face of the dielectric substrate. The right end of the first metal ground is flush with the right end face of the dielectric substrate. The width of the first metal ground is less than the length of the dielectric substrate. The second metal ground has a rectangular structure. The length of the second metal ground is along the left-right direction, and the width is along the front-back direction. The second metal ground is attached to the lower surface of the dielectric substrate. The front end of the second metal ground is flush with the front end face of the dielectric substrate. The left end of the second metal ground is flush with the left end face of the dielectric substrate. The right end of the second metal ground is flush with the right end face of the dielectric substrate. The width of the second metal ground is greater than the width of the first metal ground. Multiple metallized vias penetrate from top to bottom through the first metal ground, the dielectric substrate, and the second metal ground, connecting the first and second metal grounds to make them equipotential bodies. The plane that makes the dielectric substrate symmetrical is called the first symmetry plane. m*n rectangular metal patches are attached to the upper surface of the dielectric substrate. The length of each rectangular metal patch is along the left-right direction, and the width is along the front-back direction. The spacing between two adjacent rectangular metal patches in each row and the spacing between two rectangular metal patches in each column are equal, denoted as d. The front ends of each row of rectangular metal patches are aligned on a straight line parallel to the front end face of the dielectric substrate, and the left ends of each column of rectangular metal patches are aligned on a straight line. The straight line is parallel to the left end face of the dielectric substrate. The m rows of rectangular metal patches are sequentially referred to as the 1st row to the mth row of rectangular metal patches from back to front, and the n columns of rectangular metal patches are sequentially referred to as the 1st column to the nth column of rectangular metal patches from left to right. The straight line containing the rear end of the 1st row of rectangular metal patches is located in front of the rear end of the dielectric substrate, and the straight line containing the front end of the mth row of rectangular metal patches is located behind the rear end of the first metal ground, with a distance d between them. The straight line containing the left end of the first column of rectangular metal patches is located on the right side of the plane containing the left end face of the dielectric substrate; the straight line containing the right end of the nth column of rectangular metal patches is located on the left side of the plane containing the right end face of the dielectric substrate. The array of rectangular metal patches is symmetrical about the first symmetry plane.

3. A high-degree-of-freedom multi-antenna structure with decoupling function according to claim 2, characterized in that... Each antenna is constructed as follows: First, select a column of rectangular metal patches in the rectangular metal patch array. Starting from the m-th row of the rectangular metal patches in that column, select the corresponding number of rectangular metal patches. Then, close the switches between any two adjacent rectangular metal patches in all the selected rectangular metal patches. At this point, one antenna is constructed. Any two antennas can select rectangular metal patches from different columns. The N antennas are evenly spaced, and there are at least 3 columns of rectangular metal patches between any two adjacent antennas. If an antenna is to operate at a single frequency, and the distance between the front end of the first row of rectangular metal patches and the rear end of the m-th row of rectangular metal patches is greater than half the wavelength of its operating frequency, then the distance between the front end of the first row of rectangular metal patches and the rear end of the last row of rectangular metal patches is closest to half the wavelength of the required operating frequency. If the distance between the front end of the first row of rectangular metal patches and the rear end of the m-th row of rectangular metal patches is less than or equal to half the wavelength of its operating frequency, then the antenna selects an entire column of rectangular metal patches. If an antenna is to operate at multiple frequencies, and the distance between the front end of the first row of rectangular metal patches and the rear end of the m-th row of rectangular metal patches is greater than the average of half the wavelength of its multiple operating frequencies, then the distance between the front end of the first row of rectangular metal patches and the rear end of the last row of rectangular metal patches is closest to the average of half the wavelength of its multiple operating frequencies. If the distance between the front end of the first row of rectangular metal patches and the rear end of the m-th row of rectangular metal patches is less than or equal to the average of half the wavelength of its multiple operating frequencies, then the antenna selects an entire column of rectangular metal patches.

4. A high-degree-of-freedom multi-antenna structure with decoupling function according to claim 3, characterized in that... Let M be the number of operating frequencies of the N antennas. The N antennas are named sequentially from left to right as antenna 1 to antenna N. j Each antenna needs to be installed, including K... j The decoupling unit of each decoupling branch, K j For each integer greater than or equal to M(N-1), j =1,2,3,...,N; The decoupling structure is composed of N antenna decoupling units, and the number of decoupling branches included in the decoupling structure is denoted as S, where S is an integer greater than or equal to MN(N-1); for the i One antenna, i =2,3,…,N-1, and the decoupling branch construction area is located at the antenna and the first... i Among all decoupling branches of +1 antenna, the leftmost decoupling branch is located between them, or the antenna and the... i -1 antenna is located between the rightmost decoupling branches among all decoupling branches; For the first antenna, if it is mounted on the first column of rectangular metal patches, the area where its decoupling branch is mounted is between the leftmost decoupling branches of all decoupling branches between the first and second antennas. If the antenna is not mounted on the first column of rectangular metal patches, the area where its decoupling branch is mounted is between the leftmost decoupling branches of all decoupling branches between the first and second antennas, or to the left of the antenna. For the Nth antenna, if it is mounted on the nth column of rectangular metal patches, the area where its decoupling branch is mounted is between the rightmost decoupling branches of all decoupling branches between the first and (N-1)th antennas. If the antenna is not mounted on the nth column of rectangular metal patches, the area where its decoupling branch is mounted is between the rightmost decoupling branches of all decoupling branches between the first and (N-1)th antennas, or to the right of the antenna. The decoupling unit of any one of N antennas is constructed as follows: Let 'a' be the number of rectangular metal patches used to construct the antenna. Within the construction area of ​​the antenna, select any column of rectangular metal patches that has no other decoupling branches. Starting from the rectangular metal patch in row b of this column, select at least 3 rectangular metal patches forward. Then, either among all the selected rectangular metal patches, close the switches between any two adjacent rectangular metal patches, except for those between the rectangular metal patches in row b and row b+1, thus completing one decoupling branch, which is called a parasitic decoupling branch; or close the switches between any two adjacent rectangular metal patches, thus completing one decoupling branch, which is called a self-decoupling branch. Where 'a' is odd, then either b = ma / 2 + 1 / 2, or b = ... The formula is ma / 2-1 / 2, or b=ma / 2+3 / 2. If a is even, then either b=ma / 2+1, b=ma / 2, or b=ma / 2+2. After all decoupling branches of the antenna are built, connect all decoupling branches of the antenna according to the following connection method: Let g be the column number of the antenna in the rectangular metal patch array, that is, the antenna is built at the g-th column of the rectangular metal patch array. Let k be the column number of the leftmost decoupling branch of the antenna in the rectangular metal patch array, that is, the leftmost decoupling branch of the antenna is built at the k-th column of the rectangular metal patch array. Let h be the column number of the rightmost decoupling branch of the antenna in the rectangular metal patch array. The antenna is constructed at the rectangular metal patch in the h-th column of the array. If the decoupling branches of the antenna are distributed on its left and right sides, then the switches between every two adjacent rectangular metal patches in the h-k+1 rectangular metal patches in the b-th row of the rectangular metal patch array, located from the k-th to the h-th column, are closed. If the decoupling branches of the antenna are only distributed on its left side, then the switches between every two adjacent rectangular metal patches in the g-k+1 rectangular metal patches in the b-th row of the rectangular metal patch array, located from the k-th to the g-th column, are closed. If the decoupling branches of the antenna are only distributed on its right side, then the switches between every two adjacent rectangular metal patches in the h-g+1 rectangular metal patches in the h-th to the h-th column of the b-th row of the rectangular metal patch array are closed. At this time, the connection of all decoupling branches of the antenna is completed.After all decoupling branches of the antenna are connected, in the antenna construction area, at least one rectangular metal patch not used for constructing its decoupling branch is selected from the rectangular metal patches in the m-th to m-2-th rows of the rectangular metal patch array as the grounding metal patch of the antenna. Each grounding metal patch of the antenna has a metallized via hole running from top to bottom through the grounding metal patch, the dielectric substrate, and the second metal ground. For each decoupling branch of the antenna, the rectangular metal patch in the first row is connected to the grounding metal patch with the shortest linear distance. The switch between any two adjacent rectangular metal patches on this connection path is closed, thereby connecting each decoupling branch of the antenna to the second metal ground. When multiple grounding metal patches with the shortest linear distance exist, one of them is arbitrarily selected. The connection path is chosen using the fewest rectangular metal patches, and this connection path... No rectangular metal patch can appear on the connection path between other decoupling branches of the antenna and the grounding metal patch. When there are multiple connection paths that meet the condition of using the fewest rectangular metal patches, one is randomly selected. Determine whether the switch between each grounding metal patch and its adjacent rectangular metal patches (front, back, left, and right) is closed. If a switch is closed, connect a load in parallel across the two ends of the switch. At this point, the decoupling unit of the antenna is completed. When the decoupling units of N antennas are all completed, the decoupling structure is formed. Since each decoupling branch is connected to a grounding metal patch through a connection path, and there is no repetition of rectangular metal patches in the connection path between any decoupling branch and the grounding metal patch, there are a total of S decoupling branches. The connection path between each decoupling branch and the grounding metal patch is different and includes a load. Therefore, there are a total of S loads. The selection of S loads and load parameters ensures that the mutual admittance of any two antennas at each operating frequency meets the design requirements.

5. A high-degree-of-freedom multi-antenna structure with decoupling function according to claim 4, characterized in that... Each load is selected from either a capacitor or an inductor. When the load is a capacitor, the load parameter is the capacitance value; when the load is an inductor, the load parameter is the inductance value. Any two loads and their selected load parameters can be the same or different.

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