Broadband filtering and mutual coupling removing patch antenna with symmetric plane structure

Abstract

The invention discloses a broadband filtering and mutual coupling removing patch antenna with a symmetrical plane structure, a top metal structure of the broadband filtering and mutual coupling removing patch antenna is located on the upper surface of a dielectric substrate and comprises a C-shaped metal patch, and a vertical metal strip and a transverse metal strip are distributed on the right side of the C-shaped metal patch; wherein one end of the transverse metal strip is connected with one side of the midpoint of the vertical metal strip, and the main body part of the transverse metal strip is inserted into the C-shaped metal patch; the other side of the middle point of the vertical metal strip is connected with a rectangular metal patch; the metal ground is located on the lower surface of the dielectric substrate, and the metal probe penetrates through the metal ground and the dielectric substrate from the bottom surface and then is connected with the center of the rectangular metal patch. According to the filtering and mutual coupling removing patch antenna, the bandwidth is improved while the filtering characteristic and the mutual coupling removing characteristic are achieved, and the antenna unit is of an axisymmetric plane structure and is suitable for large-scale array forming.

Description

Technical Field

[0001] The invention relates to a microwave communication device, in particular to a broadband filtering decoupling patch antenna. Background Art

[0002] With the rapid development of microwave communication technology, especially in the application and promotion of 5G technology, multi-antenna systems such as MIMO and phased arrays are widely adopted to improve data transmission rate and system capacity. However, with the increase in the number of antennas and the compactness of space, the mutual coupling problem between antenna units has become particularly prominent, seriously affecting the performance of the system. In order to solve this problem, researchers are committed to developing new antenna structures to effectively suppress the mutual coupling between antenna units and improve the overall performance of the system.

[0003] An existing filter decoupling patch antenna design realizes the function of filter decoupling by embedding an inverted F-type resonator with loaded branches. Therefore, the antenna can not only reduce the mutual coupling between antennas in the same frequency, but also reduce the mutual coupling between antennas in adjacent frequency bands. The 10-dB matching bandwidth of the filter decoupling antenna is about 2.9%, the isolation between antenna units in the same frequency band is greater than 15.2 dB, and the isolation between antenna units in adjacent frequency bands is greater than 16.7 dB. However, the antenna is an asymmetric planar structure and is not easy to form a large-scale array. Summary of the invention

[0004] Purpose of the invention: In view of the above-mentioned prior art, a new type of filtering decoupling antenna is proposed, which has a wider bandwidth and can reduce the mutual coupling between antenna units and improve the performance of the MIMO system.

[0005] Technical solution: A broadband filtering decoupling patch antenna with a symmetrical planar structure, comprising a top metal structure, a dielectric substrate, a metal ground, and a metal probe; the top metal structure is located on the upper surface of the dielectric substrate, and comprises a C-shaped metal patch, wherein the C-shaped metal patch is a vertical large rectangular structure with a small horizontal rectangle dug out in the middle of the right long side; a vertical metal strip and a horizontal metal strip are distributed on the right side of the C-shaped metal patch; wherein one end of the horizontal metal strip is connected to one side of the midpoint of the vertical metal strip, and the The main body is inserted into the C-shaped metal patch; a rectangular metal patch is connected to the other side of the midpoint of the vertical metal strip; the metal ground is located on the lower surface of the dielectric substrate, and the metal probe passes through the metal ground and the dielectric substrate from the bottom surface and connects to the center of the rectangular metal patch; the C-shaped metal patch, the dielectric substrate and the metal ground constitute a patch resonator; the vertical metal strip, the horizontal metal strip, the rectangular metal patch, the dielectric substrate and the metal ground constitute a group of strip resonators; the metal ground, the dielectric substrate and the metal probe constitute a feeding structure.

[0006] Beneficial effects: Currently, there are only filtering decoupling antennas realized by face-to-face structures, and they are only applicable to 1×2 one-dimensional linear arrays, which are not easy to form large-scale arrays and have narrow bandwidth. The filtering decoupling patch antenna proposed in the present invention realizes filtering characteristics and decoupling characteristics while improving bandwidth. The antenna unit is also an axisymmetric planar structure, which is suitable for forming large-scale arrays.

[0007] Specifically, the antenna of the present invention couples the C-shaped metal patch structure by exciting the metal strip through a metal probe. On the one hand, the reverse electric field between the metal strip and the C-shaped metal patch is utilized; on the other hand, the effect of the C-shaped metal patch isolator is utilized to generate mutual coupling zero points and radiation zero points, thereby achieving the effects of decoupling and filtering, and finally realizing a broadband filtering decoupling patch antenna with a symmetrical planar structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 A schematic diagram of the cross-sectional structure of a broadband filtering and decoupling patch antenna with a symmetrical planar structure; Figure 2 A schematic diagram of the top view of a broadband filtering decoupling patch antenna with a symmetrical planar structure; Figure 3 The S parameters of the broadband filtering and decoupling patch antenna with symmetrical planar structure; Figure 4 The gain of the filtering decoupling patch antenna with a symmetrical planar structure; Figure 5 is the E / H plane simulation pattern of the embodiment at 3.5 GHz; Figure 6 The E / H plane simulation pattern of ports three and four of the embodiment at 3.8 GHz. DETAILED DESCRIPTION

[0009] The present invention will be further explained below in conjunction with the accompanying drawings.

[0010] A broadband filtering decoupling patch antenna with a symmetrical planar structure, wherein the 2×2 antenna element array structure is as follows: Figure 1 , Figure 2 As shown, it is composed of a top metal structure 1, a dielectric substrate 2, a metal ground 3, and a metal probe 4.

[0011] The top metal structure 1 is located on the upper surface of the dielectric substrate 2, and includes four C-shaped metal patches 11, 12, 13, and 14 arranged in a 2×2 form. The four C-shaped metal patches are of the same shape, and are formed by digging out a small horizontal rectangle in the middle of the right long side of a vertical large rectangular structure. A vertical metal strip and a horizontal metal strip are distributed on the right side of each C-shaped metal patch. One end of the horizontal metal strip is connected to one side of the midpoint of the vertical metal strip, and the main body is inserted into the C-shaped metal patch. A rectangular metal patch is connected to the other side of the midpoint of each vertical metal strip. The metal earth 3 is located on the lower surface of the dielectric substrate 2, and four metal probes 4 pass through the metal earth 3 and the dielectric substrate 2 from the bottom surface and are connected to the center of a corresponding rectangular metal patch.

[0012] The upper C-shaped metal patches 11 and 12 have the same size, and the vertical length of the large rectangular structure is 0.4λ. 01 ~0.45λ 01 Between, the lateral width is 0.25λ 01 ~ 0.3λ 01 The horizontal length of the small rectangle is between 0.15λ 01 ~ 0.2λ 01 The vertical width is between 0.1λ 01 ~ 0.15λ 01 Between 01 is the free space wavelength corresponding to the center frequency of 3.5 GHz. The center spacing between the C-shaped metal patches 11 and 12 is 0.5λ 01 The C-shaped metal patches 13 and 14 below have the same size, and the vertical length of the large rectangular structure is 0.4λ 02 ~ 0.45λ 02 Between, the lateral width is 0.25λ 02 ~ 0.3λ 02 The horizontal length of the small rectangle is between 0.15λ 02 ~ 0.2λ 02 The vertical width is between 0.1λ 02 ~ 0.15λ 02 Between 02 The center distance between the C-shaped metal patches 13 and 14 is 0.5λ. 02 .

[0013] The upper transverse metal strips 15 and 16 have the same size and a length of 0.15λ. 01 ~ 0.2λ 01 The width is between 0.02λ 01 ~ 0.025λ 01The lower horizontal metal strips 17 and 18 have the same size and their length is 0.15λ 02 ~ 0.2λ 02 The width is between 0.02λ 02 ~ 0.025λ 02 The upper vertical metal strips 19 and 110 have the same size and a length of 0.5λ 01 ~ 0.55λ 01 The width is between 0.02λ 01 ~ 0.025λ 01 The vertical metal strips 19, 110 are consistent with the distance between the sides of the C-shaped metal patches 11, 12, which is 0.05λ 01 ~ 0.1λ 01 The vertical metal strips 111 and 112 below have the same size and a length of 0.5λ. 01 ~ 0.55λ 01 The width is between 0.02λ 01 ~ 0.025λ 01 The vertical metal strips 111, 112 and the C-shaped metal patch 13, 14 are consistent with the side distance, which is 0.05λ 02 ~ 0.1λ 02 The upper rectangular metal patches 113 and 114 have the same size, and their lateral length is 0.05λ 01 ~ 0.1λ 01 The vertical width is between 0.05λ 01 ~ 0.1λ 01 The rectangular metal patches 115 and 116 below have the same size, and their lateral length is 0.05λ 02 ~ 0.1λ 02 The vertical width is between 0.05λ 02 ~ 0.1λ 02 between.

[0014] In the above structure, C-shaped metal patches 11, 12, 13, 14, dielectric substrate 2 and metal ground 3 constitute four patch resonators. Metal strips 15, 16, 17, 18, 19, 110, 111, 112, rectangular metal patches 113, 114, 115, 116, dielectric substrate 2 and metal ground 3 constitute four groups of strip resonators. Metal ground 3, dielectric substrate 2 and four metal probes 4 constitute four feeding structures, serving as ports 1 to 4 of the 2×2 antenna element array.

[0015] When the antenna is working, the signal is fed through the metal probe 4 at the bottom layer, exciting the half-wavelength mode of the strip resonator. The strip resonator couples the signal to the corresponding patch resonator and excites its TM01 mode, forming a radiation band. Among them, a rectangular C-shaped metal patch is dug out, and the coupling mode of the current path and the field is effectively changed through the unique regulation of the electromagnetic field distribution, thereby acting as an isolator to play a decoupling role. When electromagnetic waves propagate in an array containing this structure, the C-shaped metal patch can use its special shape and layout to guide the direction of electromagnetic waves within a specific frequency range, so that signal paths that may originally interfere with and couple with each other can be separated, reducing the coupling from the excitation unit, generating mutual coupling zero points, and improving the isolation level. Reverse currents can be generated between the strip resonator and the patch resonator to cancel each other out, and a radiation zero point can be generated at the upper and lower edges of the radiation band.

[0016] The dielectric substrate used in this embodiment is RO4003C, and its S parameter simulation results are as follows: Figure 3 As shown in Figure 2, the simulation results of the gain are as follows: Figure 4 The 10-dB impedance matching bandwidth of this embodiment is 7.47% (3.35GHz - 3.61 GHz) and 6.07% (3.67GHz - 3.90 GHz), the maximum gain in the working frequency band is 6.3 / 6.8dBi, the isolation in the same frequency band is greater than 30.2 / 29.7 dB, and the isolation in adjacent frequency bands is greater than 20.6dB. Figure 5 is the antenna at 3.5 GHz E / H-plane simulation radiation pattern, E The 3-dB beamwidth in the / H plane is 84.4° / 81.3°. At this frequency, E / H-plane cross-polarization level is -61.2 dB / -38.9 dB. Figure 6 is the antenna at 3.8 GHz E / H-plane simulation radiation pattern, E / The 3-dB beamwidth in the H plane is 77.7° / 74.9°. At this frequency, E / H-plane cross-polarization levels are -51.6 dB / -41.6 dB.

[0017] The present invention proposes a filtering and decoupling C-type patch antenna. Compared with the existing filtering and decoupling antenna, the antenna of the present invention has a wider bandwidth and the antenna unit adopts a symmetrical planar structure, which is more advantageous in large-scale array applications while maintaining the performance and reliability of the antenna.

[0018] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A broadband filtering and decoupling patch antenna with a symmetrical planar structure, characterized in that: The invention comprises a top metal structure (1), a dielectric substrate (2), a metal ground (3), and a metal probe (4); the top metal structure (1) is located on the upper surface of the dielectric substrate (2), and comprises a C-shaped metal patch, wherein the C-shaped metal patch is a vertical large rectangular structure with a small horizontal rectangle cut out in the middle of the right long side; a vertical metal strip and a horizontal metal strip are distributed on the right side of the C-shaped metal patch; wherein one end of the horizontal metal strip is connected to one side of the midpoint of the vertical metal strip, and the main body of the horizontal metal strip is inserted into the C-shaped metal patch; the vertical metal A rectangular metal patch is connected to the other side of the midpoint of the strip; the metal ground (3) is located on the lower surface of the dielectric substrate (2); a metal probe (4) passes through the metal ground (3) and the dielectric substrate (2) from the bottom surface and is connected to the center of the rectangular metal patch; the C-shaped metal patch, the dielectric substrate (2) and the metal ground (3) constitute a patch resonator; the vertical metal strip, the horizontal metal strip, the rectangular metal patch, the dielectric substrate (2) and the metal ground (3) constitute a group of strip resonators; the metal ground (3), the dielectric substrate (2) and the metal probe (4) constitute a feeding structure.

2. The broadband filtering decoupling patch antenna according to claim 1, characterized in that: In the broadband filtering decoupling patch antenna arranged in a 2×2 format, the upper two antenna units correspond to a first center frequency, and the lower two antenna units correspond to a second center frequency; The sizes of the two antenna units above are the same, and the vertical length of the corresponding large rectangular structure is 0.4λ 01 ~ 0.45λ 01 Between, the lateral width is 0.25λ 01 ~ 0.3λ 01 The horizontal length of the small rectangle removed is 0.15λ 01 ~ 0.2λ 01 The vertical width is between 0.1λ 01 ~ 0.15λ 01 Between 01 is the free space wavelength corresponding to the first center frequency; the center spacing between the two upper C-shaped metal patches is 0.5λ 01 ; The sizes of the two antenna units below are the same, and the vertical length of the corresponding large rectangular structure is 0.4λ 02 ~ 0.45λ 02 Between, the lateral width is 0.25λ 02 ~ 0.3λ 02 The horizontal length of the small rectangle removed is 0.15λ 02 ~ 0.2λ 02 The vertical width is between 0.1λ 02 ~ 0.15λ 02 Between 02 is the free space wavelength corresponding to the second center frequency; the center spacing between the two C-shaped metal patches below is 0.5λ 02 .

3. The broadband filtering decoupling patch antenna according to claim 2, characterized in that: In the broadband filtering decoupling patch antenna arranged in a 2×2 format, the upper two lateral metal strips have the same size and a length of 0.15λ. 01 ~0.2λ 01 The width is between 0.02λ 01 ~ 0.025λ 01 The two vertical metal strips above are of the same size, with a length of 0.5λ 01 ~ 0.55λ 01 The width is between 0.02λ 01 ~ 0.025λ 01 The distance between the two vertical metal strips on the top and the corresponding C-shaped metal patch sides is consistent, which is 0.05λ 01 ~ 0.1λ 01 between; The two horizontal metal strips below have the same size, with a length of 0.15λ 02 ~ 0.2λ 02 The width is between 0.02λ 02 ~ 0.025λ 02 The two vertical metal strips below are of the same size, with a length of 0.5λ 01 ~ 0.55λ 01 The width is between 0.02λ 01 ~ 0.025λ 01 The distance between the two vertical metal strips below and the corresponding C-shaped metal patch sides is consistent, which is 0.05λ 02 ~ 0.1λ 02 between.

4. The broadband filtering decoupling patch antenna according to claim 3, characterized in that: In the broadband filtering decoupling patch antenna arranged in a 2×2 format, the two rectangular metal patches on the top have the same size and a horizontal length of 0.05λ. 01 ~ 0.1λ 01 The vertical width is between 0.05λ 01 ~ 0.1λ 01 The two rectangular metal patches below have the same size and their lateral length is 0.05λ 02 ~ 0.1λ 02 The vertical width is between 0.05λ 02 ~ 0.1λ 02 between.

Images