A multiple-input multiple-output magnetic dipole antenna

Abstract

The present invention discloses a multi-input multi-output magnetic dipole antenna, comprising a first submodule and a second submodule, wherein the first submodule and the second submodule are electrically connected, the first submodule has a plurality of back-to-ground coplanar waveguide ports and a first waveguide resonator; the second submodule has a plurality of second waveguide resonators and a magnetic dipole antenna; the first waveguide resonator is configured to form a vertical connection structure with the second waveguide resonator to achieve a second-order filtering frequency response; the back-to-ground coplanar waveguide port is configured to form a cross-coupling structure with the magnetic dipole antenna to achieve two radiation zero points and improve frequency selectivity; a plurality of the magnetic dipole antennas are arranged so that at least two are placed in parallel, and at least one of the magnetic dipole antennas is orthogonal to the at least two parallel magnetic dipole antennas; the multi-input multi-output magnetic dipole antenna can achieve high frequency selectivity and high isolation.

Description

Technical Field

[0001] The present invention relates to the technical field of multi-input multi-output antennas, and in particular to a multi-input multi-output magnetic dipole antenna. Background Art

[0002] MIMO technology can improve channel capacity and reliability without the need for additional bandwidth and power, and is therefore widely used in 4G and 5G communication systems. MIMO antennas are key components of MIMO systems. The mutual coupling between antenna units of MIMO antennas is an important reason for the degradation of MIMO system performance. Currently, existing MIMO antennas have low frequency selectivity. At the same time, antenna units have low isolation when they are closely spaced.

[0003] According to the four-port multiple-input multiple-output dielectric resonant antenna proposed in "NK Sahu, G. Das, RK Gangwar, and K. Rambabu, Anarrangement for four-element MIMO DRA with complementary CP diversity, IEEE Antennas Wireless Propag. Lett., vol. 20, no. 9, pp. 1616-1620, Sep. 2021", the isolation of the antenna is 15 dB, which has the disadvantage of low isolation. Therefore, it is necessary to improve the antenna. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a multi-input multi-output magnetic dipole antenna which realizes high frequency selectivity and high isolation.

[0005] To solve the above problems, the present invention adopts the following technical solutions:

[0006] In a first aspect, a multi-input multi-output magnetic dipole antenna is provided, comprising: a first submodule and a second submodule.

[0007] The first submodule has a plurality of back-to-ground coplanar waveguide ports and a first waveguide resonator. The second submodule is electrically connected to the first submodule, and the second submodule has a plurality of second waveguide resonators and a magnetic dipole antenna; wherein the first waveguide resonator is configured to form a vertical connection structure with the second waveguide resonator to achieve a second-order filtering frequency response; the back-to-ground coplanar waveguide port is configured to form a cross-coupling structure with the magnetic dipole antenna to achieve two radiation zero points and improve frequency selectivity; the plurality of magnetic dipole antennas are arranged so that at least two are placed in parallel, and at least one magnetic dipole antenna is orthogonal to the at least two parallel magnetic dipole antennas.

[0008] In the multi-input multi-output magnetic dipole antenna provided by at least one embodiment of the present disclosure, the upper metal layer of the first waveguide resonator has a first slot body, the lower metal layer of the second waveguide resonator has a second slot body, and the first waveguide resonator and the second waveguide resonator form the vertical connection structure through the first slot body and the second slot body.

[0009] In the multi-input multi-output magnetic dipole antenna provided by at least one embodiment of the present disclosure, the first slot body and the second slot body are of the same size, and the positions of the first slot body and the second slot body overlap each other in the vertical direction.

[0010] In the multi-input multi-output magnetic dipole antenna provided by at least one embodiment of the present disclosure, the back-to-ground coplanar waveguide port has at least two inverted L-shaped grooves, and the back-to-ground coplanar waveguide port forms the cross-coupling structure with the magnetic dipole antenna through the at least two inverted L-shaped grooves.

[0011] In the multi-input multi-output magnetic dipole antenna provided by at least one embodiment of the present disclosure, the length of the magnetic dipole antenna is the same as the cut edge length of the second waveguide resonator.

[0012] In the multi-input multi-output magnetic dipole antenna provided by at least one embodiment of the present disclosure, the first waveguide resonator is a substrate integrated waveguide resonator, the second waveguide resonator is a half-mode substrate integrated waveguide resonator, and the back-to-ground coplanar waveguide port is a 50Ω back-to-ground coplanar waveguide port.

[0013] In a second aspect, a multi-input multi-output magnetic dipole antenna is provided, comprising: a first printed circuit board, a second printed circuit board and three filtering-type magnetic dipole antenna units.

[0014] The filtering type magnetic dipole antenna unit comprises a back-to-ground coplanar waveguide port, a substrate integrated waveguide resonator, a half-mode substrate integrated waveguide resonator and a magnetic dipole antenna; wherein the back-to-ground coplanar waveguide port and the substrate integrated waveguide resonator are arranged on a first layer of printed circuit board to form a first submodule; the half-mode substrate integrated waveguide resonator and the magnetic dipole antenna are arranged on a second layer of printed circuit board to form a second submodule; the magnetic dipole antenna is arranged such that two magnetic dipole antennas are placed in parallel, and another magnetic dipole antenna is placed orthogonally to the two parallel magnetic dipole antennas; the substrate integrated waveguide resonator is constructed to form a vertical connection structure with the half-mode substrate integrated waveguide resonator to achieve a second-order filtering frequency response; the back-to-ground coplanar waveguide port is constructed to form a cross-coupling structure with the magnetic dipole antenna to achieve two radiation zero points and improve frequency selectivity.

[0015] In the multi-input multi-output magnetic dipole antenna provided by at least one embodiment of the present disclosure, the upper metal layer of the substrate integrated waveguide resonator has a first groove body, the lower metal layer of the half-mode substrate integrated waveguide resonator has a second groove body, and the substrate integrated waveguide resonator and the half-mode substrate integrated waveguide resonator form the vertical connection structure through the first groove body and the second groove body.

[0016] In the multi-input multi-output magnetic dipole antenna provided by at least one embodiment of the present disclosure, the back-to-ground coplanar waveguide port has at least two inverted L-shaped grooves, and the back-to-ground coplanar waveguide port forms the cross-coupling structure with the magnetic dipole antenna through the at least two inverted L-shaped grooves.

[0017] The principle of the present disclosure is: the high-isolation filtering type multi-input multi-output magnetic dipole antenna provided includes three filtering type magnetic dipole antenna units, two of which are placed in parallel, and the other filtering type magnetic dipole antenna unit is placed orthogonally. Each filtering type magnetic dipole antenna includes a substrate integrated waveguide resonator, a half-mode substrate integrated waveguide resonator and a magnetic dipole antenna. The substrate integrated waveguide resonator and the half-mode substrate integrated waveguide resonator are vertically connected through a slot body, so that a second-order filtering frequency response can be achieved. The 50Ω back-to-ground coplanar waveguide port includes two inverted L-shaped slots, which form cross-coupling with the magnetic dipole antenna, and can achieve two radiation zero points, thereby improving frequency selectivity. Based on the radiation characteristics and orthogonal polarization characteristics of the magnetic dipole antenna, high isolation between antenna units is achieved.

[0018] The beneficial effects of the present invention are:

[0019] 1. It has a second-order filtering frequency response and two radiation zero points, thus achieving high frequency selectivity.

[0020] 2. Utilize the radiation characteristics and orthogonal polarization characteristics of the magnetic dipole antenna to achieve high isolation between antenna units. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 FIG. 4 is a top view of the MIMO antenna of the present invention.

[0023] Figure 2 is a top view of a single antenna unit of the present disclosure.

[0024] Figure 3Schematic diagram of the layer structure of a single antenna unit of the present invention.

[0025] Figure 4 It is a reflection coefficient simulation and test diagram of the antenna unit of a specific embodiment of the present disclosure.

[0026] Figure 5 It is a simulation and test diagram of the isolation degree of a specific embodiment of the present disclosure.

[0027] Figure 6 It is a simulation and test diagram of the gain frequency response characteristics of the antenna unit of a specific embodiment of the present disclosure.

[0028] Figure 7 It is the E-plane radiation pattern of the antenna unit of the specific embodiment of the present disclosure at 5 GHz in simulation and test.

[0029] Figure 8 It is the simulated and tested H-plane radiation pattern of the antenna unit of the specific embodiment of the present disclosure at 5 GHz.

[0030] Fig. 9 It is a simulation and test diagram of the envelope correlation coefficient of a specific embodiment of the present invention.

[0031] In the figure:

[0032] A1, filtering type magnetic dipole antenna unit 1; A2, filtering type magnetic dipole antenna unit 2; A3, filtering type magnetic dipole antenna unit 3; B1, back-to-ground coplanar waveguide port; B2, substrate integrated waveguide resonator; B3, half-mode substrate integrated waveguide resonator; B4, magnetic dipole antenna; B5, first layer printed circuit board; B6, second layer printed circuit board; B7, rectangular slot of substrate integrated waveguide resonator; B8, rectangular slot of half-mode substrate integrated waveguide resonator. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments will be described clearly and completely below in conjunction with the drawings in the embodiments. Obviously, the described embodiments are only a part of the embodiments, rather than all the embodiments.

[0034] In the embodiments, it should be understood that the terms "middle", "upper", "lower", "top", "right side", "left end", "above", "back", "middle", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, which are only for the convenience of description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should be the usual meanings understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprising" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0035] In addition, in the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms such as installation, connection and connection should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] Reference Figure 1 , Figure 2 and Figure 3 The present invention provides a multi-input and multi-output magnetic dipole antenna, comprising three filtering type magnetic dipole antenna units A1, A2 and A3 composed of two layers of printed circuit boards, each filtering type magnetic dipole antenna is composed of a 50Ω back-to-ground coplanar waveguide port B1, a substrate integrated waveguide resonator B2, a half-mode substrate integrated waveguide resonator B3 and a magnetic dipole antenna B4, the 50Ω back-to-ground coplanar waveguide port B1 and the substrate integrated waveguide resonator B2 are located on a first layer of printed circuit board B5, and the half-mode substrate integrated waveguide resonator B3 and the magnetic dipole antenna B4 are located on a second layer of printed circuit board B6.

[0037] The first printed circuit board B5 and the second printed circuit board B6 both use a RogersRT / Duroid 5880 substrate with a relative dielectric constant of 2.2.

[0038] The specific geometric dimensions of this embodiment are: L = 95.66 mm, L 0 =10.3mm, L 1 =5mm, L 2 =28.75mm, L 3=7.5mm, W=30.16mm, W 0 =1.5mm,W 1 =1.7mm, W 2 =30.16mm, W 3 =2.5mm, a=27.75mm, d=25.16mm, d 1 =4mm,d 2 =2mm.

[0039] In this embodiment, each 50Ω back-to-ground coplanar waveguide port B1 includes two inverted L-shaped slots, which form cross coupling with the magnetic dipole antenna B4.

[0040] In this embodiment, the upper metal layer of the substrate integrated waveguide resonator B2 has a rectangular groove B7, and the lower metal layer of the half-mode substrate integrated waveguide resonator B3 has a rectangular groove B8. The two rectangular grooves are of the same size and overlap in the vertical direction.

[0041] In this embodiment, two magnetic dipole antennas A1 and A2 are placed in parallel, and another magnetic dipole antenna A3 is rotated 90 degrees relative to the parallel position.

[0042] In this embodiment, the first layer of printed circuit board B5 and the second layer of printed circuit board B6 have different thicknesses, and the second layer of printed circuit board B6 has a greater thickness. The thickness of the first layer of printed circuit board B5 is 0.508 mm, and the thickness of the second layer of printed circuit board B6 is 1.575 mm.

[0043] In this embodiment, the length of the magnetic dipole antenna B4 is the same as the cut edge length of the half-mode substrate integrated waveguide B3, which is 27.75 mm.

[0044] In this embodiment, Ansys HFSS three-dimensional electromagnetic simulation software was used for simulation, and a vector network analyzer and a microwave darkroom were used for testing. Figure 4 The reflection coefficient simulation and test diagram of the antenna unit 1 of this specific embodiment are given. It can be seen from the figure that the impedance bandwidth of the simulation is 4.89-5.12 GHz, and the impedance bandwidth of the test is 4.88-5.12 GHz.

[0045] Figure 5 The isolation simulation and test diagram of this specific embodiment are given. It can be seen from the figure that the isolation between port 1 and port 2 is 20 and 24dB respectively, the isolation between port 1 and port 3 is 30 and 27dB respectively, and the isolation between port 2 and port 3 is 39 and 33dB respectively. Therefore, the antenna units of this specific embodiment have high isolation.

[0046] Figure 6The simulation and test diagrams of the gain frequency response characteristics of the antenna unit 1 of this specific embodiment are given. As can be seen from the figure, the gain values ​​at 5GHz of the simulation and test are 5.7 and 4.1dBi respectively. Due to the cross-coupling between the feeder and the antenna, two radiation zeros are generated. As can be seen from the figure, the two radiation zeros of the simulation are located at 4.44 and 6.44GHz, and the two radiation zeros of the test are located at 4.4 and 6.55GHz. The two radiation zeros generated greatly improve the frequency selectivity.

[0047] Figure 7 The simulation and test E-plane radiation patterns of the antenna unit 1 of this specific embodiment at 5 GHz are given. Figure 8 The simulation and test H-plane radiation pattern of the antenna unit 1 of this specific embodiment at 5 GHz are given. The envelope correlation coefficient (ECC) of this specific embodiment can be calculated by the following formula:

[0048]

[0049] Fig. 9 The envelope correlation coefficient simulation and test diagram of this specific embodiment are given. It can be seen from the figure that the envelope correlation coefficients of the simulation and the test are less than 0.014 and 0.004 respectively. Since the obtained envelope correlation coefficient is very small, it shows that the antenna units have good independence.

[0050] In the description of this specification, the description with reference to the terms "this embodiment", "some embodiments", "other embodiments" or "specific example" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in the embodiments or examples of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they contradict each other.

[0051] Although the embodiments of the present application have been shown and described above, the scope of protection of the present invention is not limited thereto, and any changes or substitutions that are not conceivable through creative work should be included in the scope of protection of the present invention; unless explicitly stated, any elements, actions or instructions used in this document should not be interpreted as critical or necessary.

Claims

1. A multiple-input multiple-output magnetic dipole antenna, characterized in that: include: a first printed circuit board; a second printed circuit board; as well as Three filtering magnetic dipole antenna units, each of which comprises a back-to-ground coplanar waveguide port, a substrate integrated waveguide resonator, a half-mode substrate integrated waveguide resonator and a magnetic dipole antenna; Wherein, the back-to-ground coplanar waveguide port and substrate integrated waveguide resonator are arranged on a first layer of printed circuit board to form a first submodule; The half-mode substrate integrated waveguide resonator and the magnetic dipole antenna are arranged on the second layer of the printed circuit board to form a second submodule; The magnetic dipole antennas are arranged such that two of the magnetic dipole antennas are placed in parallel, and another magnetic dipole antenna is placed orthogonally to the two parallel magnetic dipole antennas; The substrate integrated waveguide resonator is configured to form a vertical connection structure with the half-mode substrate integrated waveguide resonator to achieve a second-order filtering frequency response; The back-to-ground coplanar waveguide port is constructed to form a cross-coupling structure with the magnetic dipole antenna to achieve two radiation zero points and improve frequency selectivity.

2. A multi-input multi-output magnetic dipole antenna according to claim 1, characterized in that: The upper metal layer of the substrate integrated waveguide resonator has a first groove body, and the lower metal layer of the half-mode substrate integrated waveguide resonator has a second groove body. The substrate integrated waveguide resonator and the half-mode substrate integrated waveguide resonator form the vertical connection structure through the first groove body and the second groove body.

3. A multi-input multi-output magnetic dipole antenna according to claim 2, characterized in that: The back-to-ground coplanar waveguide port has at least two inverted L-shaped grooves, and the back-to-ground coplanar waveguide port forms the cross-coupling structure with the magnetic dipole antenna through the at least two inverted L-shaped grooves.

4. The multi-input multi-output magnetic dipole antenna according to claim 2, characterized in that: The first slot body and the second slot body have the same size, and the positions of the first slot body and the second slot body overlap each other in the vertical direction.

5. The multi-input multi-output magnetic dipole antenna according to claim 1, characterized in that: The length of the magnetic dipole antenna is the same as the cut edge length of the half-mode substrate integrated waveguide resonator.

6. The multi-input multi-output magnetic dipole antenna according to claim 1, characterized in that: The back-to-ground coplanar waveguide port is a 50Ω back-to-ground coplanar waveguide port.

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