An isolation-enhanced millimeter-wave dual-frequency dual-polarization antenna

Abstract

The present invention discloses an isolation-enhanced millimeter-wave dual-frequency dual-polarization antenna. In the antenna, a first annular metal patch and a plurality of metal pillars together constitute an isolation device; in the low frequency band, the isolation device has a band-stop characteristic, reflects the input signal back to the port, and effectively improves the isolation between the low-frequency ports; in the high frequency band, the currents on the multiple metal pillars of the isolation device are reversed and canceled to effectively reduce the isolation between the two ports, while also reducing the coupling effect of the second annular metal patch on the port; therefore, the isolation device has the effect of enhancing isolation in both frequency bands. The antenna unit of the present invention has the characteristics of simple structure, small size, dual frequency, dual polarization and high isolation, and can meet the requirements of 5G millimeter-wave broadband high-speed wireless communication systems applied to 24GHz-29GHz and 37GHz-50GHz.

Description

Technical Field

[0001] The present invention relates to the field of millimeter wave antennas, and in particular to an isolation-enhanced dual-frequency dual-polarization antenna applied to millimeter waves. Background Art

[0002] With the large-scale commercial 5G coverage and the upcoming 6G, millimeter wave as a key technology has attracted the attention of many scholars. Millimeter wave has rich spectrum resources and extremely fast response time, but the spatial loss of millimeter wave is large. In the face of these challenges, millimeter wave antennas are required to have dual polarization, miniaturization, high gain and broadband / dual-band performance. Dual-polarized patch antennas have the characteristics of ground profile and simple structure, but the isolation between ports is usually poor, which will lead to reduced antenna gain. Therefore, high-isolation millimeter wave dual-band dual-polarized antennas are of great significance.

[0003] According to investigation and understanding, the existing technologies that have been disclosed are as follows:

[0004] In the 2021 issue of IEEE Access, Yuqi He published an article titled "A Compact Dual-Band and Dual-Polarized Millimeter-Wave Beam Scanning Antenna Array for 5G Mobile Terminals", proposing a miniaturized dual-band dual-polarized antenna unit and array for 5G millimeter-wave beam scanning. The antenna unit uses a double-layer patch to achieve dual-band, with a bandwidth of 24.2-27.7GHz and 36.2-43.8GHz, low-band port isolation greater than 17dB, and high-band port isolation greater than 10dB. Not only does this antenna fail to cover the 5G millimeter-wave frequency band, but the isolation between ports is also poor, so the port isolation of the antenna unit needs to be further improved. Summary of the invention

[0005] The purpose of the present invention is to solve the defects of the above-mentioned prior art and provide an isolation-enhanced millimeter-wave dual-frequency dual-polarization antenna. The antenna realizes dual-band through a dual-loop patch antenna fed by L-shaped branch coupling, and uses a new three-dimensional isolation device to improve the isolation between ports. The antenna simultaneously realizes the characteristics of miniaturization, dual frequency, dual polarization and high isolation.

[0006] The purpose of the present invention is achieved by at least one of the following technical solutions.

[0007] An isolation-enhanced millimeter-wave dual-frequency dual-polarization antenna comprises a first dielectric substrate, a second dielectric substrate and a third dielectric substrate;

[0008] The first dielectric substrate is located below the second dielectric substrate; a metal substrate is provided on the lower surface of the first dielectric substrate, and a first metal branch, a second metal branch and a first annular metal patch are provided on the upper surface;

[0009] The second dielectric substrate is located below the third dielectric substrate; a second annular metal patch is disposed on the upper surface of the second dielectric substrate; and a third annular metal patch is disposed on the upper surface of the third dielectric substrate;

[0010] A first metal probe, a second metal probe and a plurality of metal pillars are arranged in the first dielectric substrate; the first metal probe passes through the first dielectric substrate to connect with the first metal branch and the metal substrate; the second metal probe passes through the first dielectric substrate to connect with the second metal branch and the metal substrate; the plurality of metal pillars pass through the first dielectric substrate to connect with the first annular metal patch and the metal substrate;

[0011] The first annular metal patch and multiple metal pillars together form an isolation device; in the low frequency band, the isolation device has a band-stop characteristic, reflecting the input signal back to the port, effectively improving the isolation between the low frequency ports; in the high frequency band, the currents on the multiple metal pillars of the isolation device are reversed and canceled out to effectively reduce the isolation between the two ports, while also reducing the coupling effect of the second annular metal patch on the port; therefore, the isolation device has the effect of enhancing isolation in both frequency bands.

[0012] Furthermore, the first metal branch and the second metal branch are respectively located on two diagonal extension lines of the first annular metal patch, and there is no contact between the first metal branch, the second metal branch and the first annular metal patch.

[0013] Furthermore, the first annular metal patch, the second annular metal patch and the third annular metal patch are respectively located at the center of the upper surfaces of the first dielectric substrate, the second dielectric substrate and the third dielectric substrate.

[0014] Furthermore, the materials of the first dielectric substrate, the second dielectric substrate and the third dielectric substrate are all RO4003C.

[0015] Furthermore, the first metal branch and the first metal probe form a group of L-shaped feeding structures, and the second metal branch and the second metal probe form a group of L-shaped feeding structures; the two groups of L-shaped feeding structures couple and feed the second annular metal patch and the third annular metal patch.

[0016] Furthermore, the second annular metal patch and the third annular metal patch are both in the shape of a centrosymmetric ring, including a circular ring and a polygonal ring.

[0017] Furthermore, the outer ring of the third annular metal patch is larger than the outer ring of the second annular metal patch.

[0018] Furthermore, the shape of the first annular metal patch includes a circular ring and a polygonal ring.

[0019] Furthermore, the number of the metal pillars is greater than or equal to 2.

[0020] Furthermore, the metal pillars are arranged in a centrosymmetric manner at the center of the first dielectric substrate.

[0021] The present invention has the following beneficial effects compared with the prior art:

[0022] 1. Compared with the existing millimeter wave dual-polarization dual-frequency antenna, the antenna unit of the present invention couples and feeds the dual-annular patch through L-shaped branches, thereby achieving dual frequency and miniaturization at the same time.

[0023] 2. Compared with the existing millimeter wave dual-polarization dual-frequency antenna, the antenna unit of the present invention is placed under the annular patch using a three-dimensional structure device, does not require additional volume, and improves the port isolation of the dual frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a front view of the antenna unit of Example 1 of the present invention.

[0025] Figure 2 This is a top view of the antenna unit of Example 1 of the present invention.

[0026] Figure 3 This is a top view of the antenna unit of Example 2 of the present invention.

[0027] Figure 4 It is a top view of the antenna unit of Example 3 of the present invention.

[0028] Figure 5 Schematic diagram of the S-parameter simulation results of the antenna unit of Example 1 of the present invention.

[0029] Figure 6 This is a diagram of the isolation results before and after isolation of the antenna unit of Example 1 of the present invention.

[0030] Figure 7 This is a schematic diagram of the simulation results of the radiation pattern of the antenna unit of Example 1 of the present invention with +45° polarization at 25GHz and φ=45°.

[0031] Figure 8 This is a schematic diagram of the simulation results of the radiation pattern of the antenna unit of Example 1 of the present invention with +45° polarization at 27GHz and φ=45°.

[0032] Fig. 9 This is a schematic diagram of the simulation results of the radiation pattern of the antenna unit of Example 1 of the present invention with +45° polarization at 40GHz and φ=45°.

[0033] Fig.10This is a schematic diagram of the simulation results of the radiation pattern of the antenna unit of Example 1 of the present invention with +45° polarization at 45GHz and φ=45°.

[0034] Fig.11 Schematic diagram of the S-parameter simulation results of the antenna unit of Example 2 of the present invention.

[0035] Fig.12 This is a schematic diagram of the simulation results of the radiation pattern of the antenna unit of Example 2 of the present invention with +45° polarization at 25GHz and φ=45°.

[0036] Fig.13 This is a schematic diagram of the simulation results of the radiation pattern of the antenna unit of Example 2 of the present invention with +45° polarization at 27GHz and φ=45°.

[0037] Fig.14 This is a schematic diagram of the simulation results of the radiation pattern of the antenna unit of Example 2 of the present invention with +45° polarization at 40GHz and φ=45°.

[0038] Fig.15 This is a schematic diagram of the simulation results of the radiation pattern of the antenna unit of Example 2 of the present invention with +45° polarization at 45GHz and φ=45°.

[0039] Fig.16 Schematic diagram of the S-parameter simulation results of the antenna unit of Example 3 of the present invention.

[0040] Fig.17 This is a schematic diagram of the simulation results of the radiation pattern of the antenna unit of Example 3 of the present invention with +45° polarization at 25GHz and φ=45°.

[0041] Fig.18 This is a schematic diagram of the simulation results of the radiation pattern of the antenna unit of Example 3 of the present invention with +45° polarization at 27GHz and φ=45°.

[0042] Fig.19 This is a schematic diagram of the simulation results of the radiation pattern of the antenna unit of Example 3 of the present invention with +45° polarization at 40GHz and φ=45°.

[0043] Fig. 20 This is a schematic diagram of the simulation results of the radiation pattern of the antenna unit of Example 3 of the present invention with +45° polarization at 45GHz and φ=45°. DETAILED DESCRIPTION

[0044] The present invention is further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0045] Embodiment 1:

[0046] An isolation-enhanced millimeter-wave dual-band dual-polarization antenna, such as Figure 1 and Figure 2 As shown, it includes a first dielectric substrate a, a second dielectric substrate b and a third dielectric substrate c;

[0047] The first dielectric substrate a is located below the second dielectric substrate b; a metal substrate 4 is provided on the lower surface of the first dielectric substrate a, and a first metal branch 5a, a second metal branch 5b and a first annular metal patch 1 are provided on the upper surface;

[0048] The second dielectric substrate b is located below the third dielectric substrate c; a second annular metal patch 2 is provided on the upper surface of the second dielectric substrate b; a third annular metal patch 3 is provided on the upper surface of the third dielectric substrate c;

[0049] In this embodiment, the number of metal pillars is 4; the first dielectric substrate a is provided with a first metal probe 6a, a second metal probe 6b, a first metal pillar 7a, a second metal pillar 7b, a third metal pillar 7c and a fourth metal pillar 7d; the first metal probe 6a passes through the first dielectric substrate a to connect with the first metal branch 5a and the metal substrate 4; the second metal probe 6b passes through the first dielectric substrate a to connect with the second metal branch 5b and the metal substrate 4; the first metal pillar 7a, the second metal pillar 7b, the third metal pillar 7c and the fourth metal pillar 7d all pass through the first dielectric substrate a to connect with the first annular metal patch 1 and the metal substrate 4;

[0050] In order to improve the port isolation of the antenna unit, the first annular metal patch 1 and the first metal column 7a, the second metal column 7b, the third metal column 7c and the fourth metal column 7d together form a three-dimensional isolation device; in the low frequency band, the isolation device has a band-stop characteristic, and reflects the input signal back to the port, which effectively improves the isolation between the low-frequency ports; in the high frequency band, the currents on the first metal column 7a, the second metal column 7b, the third metal column 7c and the fourth metal column 7d of the isolation device are reversed and cancel each other out, effectively reducing the isolation between the two ports, and at the same time reducing the coupling effect of the second annular metal patch 2 on the port; therefore, the isolation device has the effect of enhancing isolation in both frequency bands.

[0051] The first metal branch node 5a and the second metal branch node 5b are respectively located on the two diagonal extension lines of the first annular metal patch 1, and there is no contact between the first metal branch node 5a, the second metal branch node 5b and the first annular metal patch 1;

[0052] The first annular metal patch 1, the second annular metal patch 2 and the third annular metal patch 3 are respectively located at the center of the upper surfaces of the first dielectric substrate a, the second dielectric substrate b and the third dielectric substrate c.

[0053] In this embodiment, the materials of the first dielectric substrate a, the second dielectric substrate b and the third dielectric substrate c are all RO4003C, whose relative dielectric constant is 3.38 and loss tangent is 0.0027.

[0054] In this embodiment, the first metal branch 5a and the first metal probe 6a form a group of L-shaped feeding structures, and the second metal branch 5b and the second metal probe 6b form a group of L-shaped feeding structures; the two groups of L-shaped feeding structures couple and feed the second annular metal patch 2 and the third annular metal patch 3. Among them, the size of the third annular metal patch 3 mainly determines the low-frequency resonance point, and the size of the second annular metal patch 2 mainly determines the low-frequency resonance point.

[0055] In this embodiment, the second annular metal patch 2 and the third annular metal patch 3 are both in the shape of square rings. The outer ring of the third annular metal patch 3 is larger than the outer ring of the second annular metal patch 2.

[0056] In this embodiment, the first annular metal patch 1 is in the shape of a square ring.

[0057] In this embodiment, the first metal pillar 7a, the second metal pillar 7b, the third metal pillar 7c and the fourth metal pillar 7d are arranged in a centrosymmetric manner at the center of the first dielectric substrate a.

[0058] The isolation-enhanced millimeter-wave dual-frequency dual-polarized antenna of this embodiment is verified and simulated by HFSS software simulation. In this implementation case, the size of the isolation-enhanced millimeter-wave dual-frequency dual-polarized antenna unit is 2mm×2mm×1.32mm. Figure 5 As shown in the figure, the S parameter simulation results of the isolation enhanced millimeter wave dual-band dual-polarization antenna are given. The working frequency band of the antenna unit is 23.84GHz-29.32GHz and 36.88GHz-50.00GHz, which can cover the 5G millimeter wave frequency band. Figure 6 As shown in the figure, after adding the three-dimensional isolation device, the port isolation of the dual-band is significantly improved, the low-frequency isolation is generally improved by 7dB, and the high-frequency isolation is generally improved by 11dB. Figure 7 , Figure 8 , Fig. 9 and Fig.10 As shown, the simulation results of the radiation pattern of the isolation-enhanced millimeter-wave dual-frequency dual-polarization antenna with +45° polarization at 25GHz, 27GHz, 40GHz and 45GHz are given respectively, and the cross-polarization is 24dB, 29dB, 18dB and 25dB respectively. Therefore, the simulation results show that the isolation-enhanced millimeter-wave dual-frequency dual-polarization antenna of the present invention can be well applied in the 5G millimeter-wave frequency band. The three-dimensional isolation device can significantly improve the port isolation of the dual-frequency band and suppress cross-polarization.

[0059] Embodiment 2:

[0060] An isolation-enhanced millimeter-wave dual-band dual-polarization antenna, such as Figure 1 and Figure 2As shown, it includes a first dielectric substrate a, a second dielectric substrate b and a third dielectric substrate c;

[0061] The first dielectric substrate a is located below the second dielectric substrate b; a metal substrate 4 is provided on the lower surface of the first dielectric substrate a, and a first metal branch 5a, a second metal branch 5b and a first annular metal patch 1 are provided on the upper surface;

[0062] The second dielectric substrate b is located below the third dielectric substrate c; a second annular metal patch 2 is provided on the upper surface of the second dielectric substrate b; a third annular metal patch 3 is provided on the upper surface of the third dielectric substrate c;

[0063] In this embodiment, Figure 3 As shown, the difference from Example 1 is that the isolation device is composed of two metal pillars, namely the first annular metal patch 1, the first metal pillar 7a and the second metal pillar 7b, and the first metal pillar 7a and the second metal pillar 7b are arranged in a centrally symmetrical manner at the center of the first dielectric substrate a.

[0064] This embodiment is verified by HFSS software simulation. Fig.11 As shown in FIG. 1 , the S parameter simulation result diagram of this embodiment is given, and the operating frequency band is 23.58 GHz-29.89 GHz and 36.72 GHz-48.29 GHz. Fig.12 , Fig.13 , Fig.14 and Fig.15 As shown, the radiation pattern simulation results of the +45° polarization of this embodiment at 25GHz, 27GHz, 40GHz and 45GHz are respectively given, and the cross-polarization is 26dB, 12dB, 12dB and 11dB respectively. The simulation results show that the port isolation and the suppression effect of cross-polarization of this embodiment are improved, but the isolation enhancement effect is worse than that of Example 1.

[0065] Embodiment three:

[0066] An isolation-enhanced millimeter-wave dual-band dual-polarization antenna, such as Figure 1 and Figure 2 As shown, it includes a first dielectric substrate a, a second dielectric substrate b and a third dielectric substrate c;

[0067] The first dielectric substrate a is located below the second dielectric substrate b; a metal substrate 4 is provided on the lower surface of the first dielectric substrate a, and a first metal branch 5a, a second metal branch 5b and a first annular metal patch 1 are provided on the upper surface;

[0068] The second dielectric substrate b is located below the third dielectric substrate c; a second annular metal patch 2 is provided on the upper surface of the second dielectric substrate b; a third annular metal patch 3 is provided on the upper surface of the third dielectric substrate c;

[0069] In this embodiment, Figure 4 As shown, the difference from Embodiment 1 is that the shape of the first annular metal patch 1 of the isolation device is changed from a square to a ring.

[0070] This embodiment is verified by HFSS software simulation. Fig.16 As shown in FIG. 1 , the S parameter simulation result diagram of this embodiment is given, and the operating frequency band is 23.98 GHz-29.58 GHz and 36.96 GHz-49.94 GHz. Fig.17 , Fig.18 , Fig.19 and Fig. 20 As shown, the radiation pattern simulation results of the +45° polarization of this embodiment at 25GHz, 27GHz, 40GHz and 45GHz are respectively given, and the cross polarizations are 26dB, 18dB, 10dB and 17dB respectively. The simulation results show that the port isolation of this embodiment is significantly improved, which is similar to the isolation effect of Example 1.

[0071] The simulation results of the above three embodiments show that the three-dimensional isolation device can significantly improve the port isolation of the dual-band millimeter-wave dual-frequency dual-polarization antenna, and the device has a simple structure and does not require additional space, which meets the characteristics of the millimeter-wave antenna that needs to be miniaturized.

[0072] The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solution and inventive concept of the present invention within the scope disclosed by the present invention, which all belong to the protection scope of the present invention.

Claims

1. An isolation-enhanced millimeter-wave dual-frequency dual-polarization antenna, characterized in that: It comprises a first dielectric substrate (a), a second dielectric substrate (b) and a third dielectric substrate (c); The first dielectric substrate (a) is located below the second dielectric substrate (b); a metal substrate (4) is provided on the lower surface of the first dielectric substrate (a), and a first metal branch (5a), a second metal branch (5b) and a first annular metal patch (1) are provided on the upper surface; The second dielectric substrate (b) is located below the third dielectric substrate (c); a second annular metal patch (2) is provided on the upper surface of the second dielectric substrate (b); and a third annular metal patch (3) is provided on the upper surface of the third dielectric substrate (c); A first metal probe (6a), a second metal probe (6b) and a plurality of metal pillars are arranged in the first dielectric substrate (a); the first metal probe (6a) passes through the first dielectric substrate (a) to be connected to the first metal branch (5a) and the metal substrate (4); the second metal probe (6b) passes through the first dielectric substrate (a) to be connected to the second metal branch (5b) and the metal substrate (4); the plurality of metal pillars pass through the first dielectric substrate (a) to be connected to the first annular metal patch (1) and the metal substrate (4); The first metal branch node (5a) and the second metal branch node (5b) are respectively located on two diagonal extension lines of the first annular metal patch (1), and there is no contact between the first metal branch node (5a), the second metal branch node (5b) and the first annular metal patch (1); The first annular metal patch (1), the second annular metal patch (2) and the third annular metal patch (3) are respectively located at the center of the upper surface of the first dielectric substrate (a), the second dielectric substrate (b) and the third dielectric substrate (c); The first metal branch (5a) and the first metal probe (6a) form a group of L-shaped feeding structures, and the second metal branch (5b) and the second metal probe (6b) form a group of L-shaped feeding structures; the two groups of L-shaped feeding structures couple and feed the second annular metal patch (2) and the third annular metal patch (3); The outer ring of the third annular metal patch (3) is larger than the outer ring of the second annular metal patch (2).

2. The isolation-enhanced millimeter-wave dual-frequency dual-polarization antenna according to claim 1, characterized in that: The materials of the first dielectric substrate (a), the second dielectric substrate (b) and the third dielectric substrate (c) are all RO4003C.

3. The isolation-enhanced millimeter-wave dual-frequency dual-polarization antenna according to claim 1, characterized in that: The second annular metal patch (2) and the third annular metal patch (3) are both in the shape of centrosymmetric rings, including circular rings and polygonal rings.

4. The isolation-enhanced millimeter-wave dual-frequency dual-polarization antenna according to claim 1, characterized in that: The shape of the first annular metal patch (1) includes a circular ring and a polygonal ring.

5. The isolation-enhanced millimeter-wave dual-frequency dual-polarization antenna according to claim 1, characterized in that: The number of metal pillars is greater than or equal to 2.

6. The isolation-enhanced millimeter-wave dual-frequency dual-polarization antenna according to claim 1, characterized in that: The metal pillars are arranged in a centrosymmetric manner at the center of the first dielectric substrate (a).

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