A broadband polarization reconfigurable array antenna

Abstract

The present invention relates to the field of antenna technology, and discloses a broadband polarization reconfigurable array antenna, comprising a dielectric substrate and four unit antennas, wherein a metal grounding layer is provided on the upper surface of the dielectric substrate, and the four unit antennas are arranged on the metal grounding layer to form a one-dimensional linear array, and a coupling gap is provided on the metal grounding layer, and a microstrip line layer is provided on the lower surface of the dielectric substrate, and two DC bias circuits are also provided on the microstrip line layer, and the dielectric substrate is connected to a feeding mechanism through the microstrip line layer, and the feeding mechanism is used to feed the unit antennas. The broadband polarization reconfigurable array antenna, by introducing two groups of broadband adjustable phase shifters in the feeding network, is integrated with each unit antenna, and compared with the general polarization reconfigurable array antenna, has stable gain, wide bandwidth, simple structure, and is easy to expand to a larger array scale without increasing the complexity of switch elements and bias circuits.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, in particular to a broadband polarization reconfigurable array antenna. Background Art

[0002] The rapid development of wireless communication technology has put forward higher requirements for system needs. Traditional single-function antennas cannot meet current needs well and have become a bottleneck restricting the development of system performance. The proposal and development of reconfigurable antennas provide a good solution to these problems. Reconfigurable antennas can increase system capacity through frequency reuse and solve the problem of polarization mismatch in communication, thereby improving communication quality.

[0003] Since modern single-layer PCB technology and metal 3D printing technology are very mature, the processing accuracy is also very guaranteed in the not very high frequency band. At the same time, the processed products can have the characteristics of low profile, small volume and high integration, which is conducive to the large-scale production and application of antennas. Therefore, the polarization reconfigurable magnetic-electric coupled polar array antenna combined with single-layer PCB technology and metal 3D printing technology has very practical significance in terms of broadband, high gain and cost reduction.

[0004] At present, in the existing polarization reconfigurable array antenna technology, the number of switching elements required will continue to increase with the expansion of the array scale. On the one hand, it will inevitably lead to an increase in product costs. On the other hand, the increase in switching elements will increase the complexity of the bias circuit, thereby weakening the system stability. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the shortcomings of the prior art, the present invention provides a broadband polarization reconfigurable array antenna, which has the advantages of introducing two groups of broadband adjustable phase shifters into a feeding network and integrating them with each unit antenna. Compared with a general polarization reconfigurable array antenna, the present invention has the advantages of stable gain, wide bandwidth, simple structure, and easy expansion to a larger array scale without increasing the complexity of switch elements and bias circuits. It solves the problem in the existing polarization reconfigurable array antenna technology that the number of switch elements required will continue to increase with the expansion of the array scale, resulting in an increase in product cost, and the increase in switch elements will increase the complexity of the bias circuit, resulting in weakened system stability.

[0007] (II) Technical solution

[0008] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a broadband polarization reconfigurable array antenna, comprising a dielectric substrate and four unit antennas, wherein a metal grounding layer is provided on the upper surface of the dielectric substrate, the four unit antennas are arranged on the metal grounding layer to form a one-dimensional linear array, and a coupling gap is provided on the metal grounding layer;

[0009] A microstrip line layer is provided on the lower surface of the dielectric substrate, and two DC bias circuits are also provided on the microstrip line layer. The dielectric substrate is connected to a feeding mechanism through the microstrip line layer, and the feeding mechanism is used to feed the unit antenna and simultaneously control different excitation phases applied to the unit antenna to produce different polarization states.

[0010] Preferably, the feeding mechanism includes a broadband 90° adjustable phase shifter, a broadband 180° adjustable phase shifter, a one-to-two equal amplitude and equal phase power distributor and two one-to-four equal amplitude and equal phase power distributors, the four unit antennas are each provided with two orthogonal feeding ports, and are respectively connected to the four output branches of the one-to-four equal amplitude and equal phase power distributor, the input ends of the two one-to-four equal amplitude and equal phase power distributors are respectively connected to the broadband 90° adjustable phase shifter and the broadband 180° adjustable phase shifter, and the broadband 90° adjustable phase shifter and the broadband 180° adjustable phase shifter are respectively connected to the two output branches of the one-to-two equal amplitude and equal phase power distributor.

[0011] Preferably, the four output branches of the one-to-four equal-amplitude and equal-phase power divider are respectively fed to the feeding port corresponding to each unit antenna, so that the excitation phases of the feeding ports corresponding to each unit antenna remain consistent.

[0012] Preferably, the unit antenna is composed of four metal magnetoelectric couplers, and the metal magnetoelectric couplers serve as radiators. The four metal magnetoelectric couplers are equidistantly arranged and correspond to the coupling gap. The unit antenna is provided with two orthogonal feeding ports that feed the coupling gap through orthogonal U-shaped microstrip lines, and a bridge structure is adopted at the junction of the two orthogonal U-shaped microstrip lines.

[0013] Preferably, the broadband 90° adjustable phase shifter and the broadband 180° adjustable phase shifter are used to control the excitation phase of the orthogonal feeding port corresponding to each unit antenna, and four different phase combinations can be provided through only two DC bias circuits to form a variety of different polarized waves.

[0014] (III) Beneficial effects

[0015] Compared with the prior art, the present invention provides a broadband polarization reconfigurable array antenna, which has the following beneficial effects:

[0016] 1. When the present invention is used, the traditional PCB or LTCC process and 3D printing technology are used to manufacture the array antenna, and the entire array antenna is mainly composed of a metal magnetoelectric coupler and a microstrip line layer. Two one-to-four equal amplitude and equal phase power distributors, a broadband 90° adjustable phase shifter, a broadband 180° adjustable phase shifter and a one-to-two equal amplitude and equal phase power distributor are arranged in the microstrip line layer. Each unit antenna is provided with two orthogonal feeding ports, and is respectively connected to the four output branches of the one-to-four equal amplitude and equal phase power distributor. The input ends of the two one-to-four equal amplitude and equal phase power distributors are respectively connected to the broadband 90° adjustable phase shifter and the broadband 180° adjustable phase shifter. The broadband 90° adjustable phase shifter and the broadband 180° adjustable phase shifter are respectively connected to the two output branches of the one-to-two equal amplitude and equal phase power distributor 11, thereby realizing the use of the broadband 90° adjustable phase shifter and the broadband 180° adjustable phase shifter to control the excitation phase of the corresponding port of each unit antenna, thereby changing the working polarization state of the array antenna.

[0017] 2. The array antenna achieves different working polarizations by changing the states of the broadband 90° adjustable phase shifter and the broadband 180° adjustable phase shifter only through two DC bias circuits, thereby satisfying better polarization characteristics, better standing wave characteristics and wider working bandwidth. At the same time, the bias circuit is simple and easy to expand to a larger array without adding additional switching elements and bias circuit complexity. It only needs to design a corresponding one-to-many equal-amplitude and equal-phase power divider for a larger array scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A structural diagram of a broadband polarization reconfigurable array antenna proposed by the present invention;

[0019] Figure 2 A schematic diagram of the structure of a metal grounding layer on a dielectric substrate in a broadband polarization reconfigurable array antenna proposed by the present invention;

[0020] Figure 3 A schematic diagram of the structure of a microstrip line layer on a dielectric substrate in a broadband polarization reconfigurable array antenna proposed by the present invention;

[0021] Figure 4 A schematic diagram of the structure of a metallized through hole in a broadband polarization reconfigurable array antenna proposed by the present invention;

[0022] Figure 5 The return loss of the left-hand circular polarization array antenna simulation and test when the broadband polarization reconfigurable array antenna proposed by the present invention is working;

[0023] Figure 6The return loss of the array antenna in the right-hand circular polarization state when the broadband polarization reconfigurable array antenna proposed by the present invention is simulated and tested;

[0024] Figure 7 The return loss of the array antenna in the X-line polarization state simulation and test when the broadband polarization reconfigurable array antenna proposed by the present invention is working;

[0025] Figure 8 The return loss of the Y-line polarization array antenna simulation and test when the broadband polarization reconfigurable array antenna proposed by the present invention is working;

[0026] Fig. 9 It is the normalized gain pattern actually measured when the broadband polarization reconfigurable array antenna proposed by the present invention is in left-hand circular polarization state at a frequency of 3.25 GHz;

[0027] Fig.10 A broadband polarization reconfigurable array antenna proposed by the present invention is in a right-hand circular polarization state when working, and the measured normalized gain pattern of the array antenna at a frequency of 3.25 GHz;

[0028] Fig.11 It is the normalized gain pattern actually measured when the broadband polarization reconfigurable array antenna proposed by the present invention is in X-line polarization state and at a frequency of 3.25 GHz;

[0029] Fig.12 A broadband polarization reconfigurable array antenna proposed by the present invention is in a Y-linear polarization state when working, and the measured normalized gain pattern of the array antenna at a frequency of 3.25 GHz;

[0030] Fig.13 A broadband polarization reconfigurable array antenna proposed by the present invention is in a left-hand circular polarization state when working, and a graph showing the relationship between the measured gain of the array antenna in the normal direction and the frequency;

[0031] Fig.14 A broadband polarization reconfigurable array antenna proposed by the present invention is in a right-hand circular polarization state when working, and a graph showing the relationship between the measured gain of the array antenna in the normal direction and the frequency;

[0032] Fig.15 A broadband polarization reconfigurable array antenna proposed by the present invention is in an X-line polarization state when working, and a graph showing the relationship between the measured gain of the array antenna in the normal direction and the frequency;

[0033] Fig.16 The diagram is a relationship between the measured gain of a broadband polarization reconfigurable array antenna proposed by the present invention and the frequency when the array antenna is in a Y-linear polarization state in the normal direction.

[0034] In the figure: 1. dielectric substrate; 2. metal ground layer; 3. coupling gap; 4. metal magnetoelectric coupler; 5. unit antenna; 6. one-to-four equal amplitude and equal phase power divider; 7. DC bias circuit; 8. orthogonal U-shaped microstrip line; 9. broadband 180° adjustable phase shifter; 10. broadband 90° adjustable phase shifter; 11. one-to-two equal amplitude and equal phase power divider; 12. microstrip line layer. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Example:

[0037] Refer to the attached Figure 1-4 A broadband polarization reconfigurable array antenna, comprising a dielectric substrate 1 and four unit antennas 5, a metal grounding layer 2 is provided on the upper surface of the dielectric substrate 1, the four unit antennas 5 are arranged on the metal grounding layer 2 to form a one-dimensional linear array, a coupling slot 3 is provided on the metal grounding layer 2, the unit antenna 5 is composed of four metal magnetic electric couplers 4, and the metal magnetic electric couplers 4 are used as radiators, the four metal magnetic electric couplers 4 are equidistantly arranged and correspond to the coupling slots 3, the unit antenna 5 is provided with two orthogonal feeding ports to feed the coupling slots 3 through orthogonal U-shaped microstrip lines 8, and the junctions of the two orthogonal U-shaped microstrip lines 8 adopt a bridge structure;

[0038] A microstrip line layer 12 is provided on the lower surface of the dielectric substrate 1, and two DC bias circuits 7 are also provided on the microstrip line layer 12. The dielectric substrate 1 is connected to a feeding mechanism through the microstrip line layer 12, and the feeding mechanism is used to feed the unit antenna 5 and simultaneously control the application of different excitation phases to the unit antenna 5 to produce different polarization states.

[0039] The feeding mechanism includes a broadband 90° adjustable phase shifter 10, a broadband 180° adjustable phase shifter 9, a one-to-two equal amplitude and equal phase power distributor 11 and two one-to-four equal amplitude and equal phase power distributors 6. The four unit antennas 5 are each provided with two orthogonal feeding ports, and are respectively connected to the four output branches of the one-to-four equal amplitude and equal phase power distributor 6. The input ends of the two one-to-four equal amplitude and equal phase power distributors 6 are respectively connected to the broadband 90° adjustable phase shifter 10 and the broadband 180° adjustable phase shifter 9. The broadband 90° adjustable phase shifter 10 and the broadband 180° adjustable phase shifter 9 are respectively connected to the one-to-two equal amplitude and equal phase power distributors 6. The two output branches of the amplitude equal-phase power divider 11 are connected, and the four output branches of the one-to-four equal-amplitude equal-phase power divider 6 are respectively fed to the feeding port corresponding to each unit antenna 5, so that the excitation phase of the feeding port corresponding to each unit antenna 5 remains consistent. The broadband 90° adjustable phase shifter 10 and the broadband 180° adjustable phase shifter 9 are used to control the excitation phase of the orthogonal feeding port corresponding to each unit antenna 5. Four different phase combinations can be provided through only two DC bias circuits 7 to form a variety of different polarized waves, namely left-hand circular polarization, right-hand circular polarization, X-line polarization and Y-line polarization.

[0040] When the present invention is used, the traditional PCB or LTCC process and 3D printing technology are used to manufacture the array antenna, and the entire array antenna is mainly composed of a metal magnetoelectric coupler 4 and a microstrip line layer 12. Two one-to-four equal amplitude and equal phase power dividers 6, a broadband 90° adjustable phase shifter 10, a broadband 180° adjustable phase shifter 9 and a one-to-two equal amplitude and equal phase power divider 11 are arranged on the microstrip line layer 12. Each unit antenna 5 is provided with two orthogonal feeding ports, and is respectively connected to the four output branches of the one-to-four equal amplitude and equal phase power divider 6. The input ends of the two one-to-four equal amplitude and equal phase power dividers 6 are respectively connected to the broadband 90° adjustable phase shifter 10 and the broadband 180° adjustable phase shifter 9. The broadband 90° adjustable phase shifter 10 and the broadband 180° adjustable phase shifter 9 are respectively connected to the The two output branches of the one-to-two equal-amplitude and equal-phase power divider 11 are connected, so as to realize controlling the excitation phase of the corresponding port of each unit antenna 5 by using the broadband 90° adjustable phase shifter 10 and the broadband 180° adjustable phase shifter 9, changing the working polarization state of the array antenna, and realizing different working polarizations by only changing the states of the broadband 90° adjustable phase shifter 10 and the broadband 180° adjustable phase shifter 9 through two DC bias circuits 7, so as to meet better polarization characteristics, better standing wave characteristics and wider working bandwidth, and at the same time, the bias circuit result is simple and easy to expand to a larger array, and there is no need to increase the complexity of the additional switching elements and the bias circuit, and it is only necessary to design a corresponding one-to-many equal-amplitude and equal-phase power divider for a larger array scale, such as setting 8 unit antennas 5, and it is necessary to design a one-to-eight equal-amplitude and equal-phase power divider.

[0041] Based on the idea of ​​the present invention, a broadband polarization reconfigurable array antenna is manufactured using PCB technology and 3D printing technology, and relevant tests are carried out: Figure 5 Simulated and tested return loss for left-hand circularly polarized array antenna; Figure 6 Simulated and tested return loss for right-hand circularly polarized array antennas; Figure 7 Simulate and test return loss for X-line polarization array antennas; Figure 8 Simulate and test the return loss of the Y-polarization array antenna; Fig. 9 It is the measured normalized gain pattern of the left-hand circularly polarized array antenna at a frequency of 3.25 GHz; Fig.10 It is the measured normalized gain pattern of the right-hand circular polarization array antenna at a frequency of 3.25 GHz; Fig.11 It is the measured normalized gain pattern of the array antenna in X-line polarization state at a frequency of 3.25 GHz; Fig.12 It is the measured normalized gain pattern of the array antenna in Y-linear polarization state at a frequency of 3.25 GHz; Fig.13 This is the relationship between the measured gain of the left-hand circularly polarized array antenna in the normal direction and the frequency; Fig.14 This is the relationship between the measured gain of the right-hand circularly polarized array antenna in the normal direction and the frequency; Fig.15 This is the relationship between the measured gain of the array antenna in the normal direction and the frequency; Fig.16 The figure shows the relationship between the measured gain and frequency in the normal direction of the Y-line polarization array antenna. Tests show that the array antenna has four different polarization states: left-hand circular polarization, right-hand circular polarization, X-line polarization and Y-line polarization, while satisfying good polarization characteristics, good standing wave characteristics, wide working bandwidth, small gain fluctuation, simple implementation, and easy expansion to larger array antennas without the need to increase the complexity of switching components and bias circuits.

[0042] It should be noted that the term "comprises" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article, or device that includes a series of elements includes not only those elements, but also includes other elements that are not explicitly listed, or also includes elements inherent to such process, method, article, or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article, or device that includes the element.

[0043] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A broadband polarization reconfigurable array antenna, comprising a dielectric substrate (1) and four unit antennas (5), characterized in that: A metal grounding layer (2) is provided on the upper surface of the dielectric substrate (1); the four unit antennas (5) are arranged on the metal grounding layer (2) to form a one-dimensional linear array; and a coupling gap (3) is provided on the metal grounding layer (2); A microstrip line layer (12) is provided on the lower surface of the dielectric substrate (1), two DC bias circuits (7) are also provided on the microstrip line layer (12), the dielectric substrate (1) is connected to a feeding mechanism via the microstrip line layer (12), the feeding mechanism is used to feed the unit antenna (5) and simultaneously control the application of different excitation phases to the unit antenna (5) to generate different polarization states; The feeding mechanism comprises a broadband 90° adjustable phase shifter (10), a broadband 180° adjustable phase shifter (9), a one-to-two equal amplitude and equal phase power distributor (11) and two one-to-four equal amplitude and equal phase power distributors (6); the four unit antennas (5) are each provided with two orthogonal feeding ports and are respectively connected to four output branches of the one-to-four equal amplitude and equal phase power distributor (6); the input ends of the two one-to-four equal amplitude and equal phase power distributors (6) are respectively connected to the broadband 90° adjustable phase shifter (10) and the broadband 180° adjustable phase shifter (9); the broadband 90° adjustable phase shifter (10) and the broadband 180° adjustable phase shifter (9) are respectively connected to two output branches of the one-to-two equal amplitude and equal phase power distributor (11).

2. The broadband polarization reconfigurable array antenna according to claim 1, characterized in that: The four output branches of the one-to-four equal-amplitude equal-phase power distributor (6) are respectively fed to the feeding port corresponding to each unit antenna (5), so that the excitation phases of the feeding ports corresponding to each unit antenna (5) remain consistent.

3. The broadband polarization reconfigurable array antenna according to claim 1, characterized in that: The unit antenna (5) is composed of four metal magnetic electric couplers (4), and the metal magnetic electric couplers (4) serve as radiators. The four metal magnetic electric couplers (4) are arranged at equal distances and correspond to the coupling slot (3). The unit antenna (5) is provided with two orthogonal feeding ports for feeding the coupling slot (3) via orthogonal U-shaped microstrip lines (8), and a bridge structure is used at the junction of the two orthogonal U-shaped microstrip lines (8).

4. The broadband polarization reconfigurable array antenna according to claim 1, characterized in that: The broadband 90° adjustable phase shifter (10) and the broadband 180° adjustable phase shifter (9) are used to control the excitation phase of the orthogonal feeding port corresponding to each unit antenna (5), and four different phase combinations can be provided by only two DC bias circuits (7), thereby forming a plurality of different polarized waves.

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