Dual-frequency polarization directional diagram diversity antenna

Abstract

The invention relates to the technical field of antennas, in particular to a dual-frequency polarization directional diagram diversity antenna. The antenna comprises a first dielectric substrate and a second dielectric substrate, a square patch is arranged on the upper surface of the first dielectric substrate, and four rectangular grooves are symmetrically formed in four corners of the square patch; the upper surface of the second dielectric substrate is provided with a split resonant ring and a microstrip transmission line, one end of the microstrip transmission line is connected with the split resonant ring, and the other end of the microstrip transmission line is provided with a feed port. The antenna can generate a circular polarization radiation characteristic of a wide axial ratio wave beam in a low frequency band, presents two axial ratio minimum values in a bandwidth, and can meet the communication requirement between a vehicle and a satellite; and a linearly polarized quasi-omnidirectional radiation pattern can be generated at a high frequency band, so that the antenna can meet the communication requirement between a vehicle and a wireless network. The antenna provided by the invention has the characteristics of small size, low profile, simple structure, low cost and the like.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, specifically to a dual-frequency polarization pattern diversity antenna. Background Technology

[0002] With the accelerated development of autonomous driving technology driven by 5G communication, stable real-time information exchange between vehicles and other devices (such as satellites, other vehicles, and mobile communication network equipment) is of great significance. Specifically, navigation antennas suitable for V2S (Vehicle-to-Satellite) typically need to operate in the 1.575GHz band, and to ensure stable reception of navigation signals and high-precision positioning, they must maintain good circular polarization purity over a wide angle range. Meanwhile, V2N (Vehicle-to-Network) antennas typically operate in the 3.3GHz band, radiating linearly polarized waves; to adapt to changes in vehicle mobility and attitude, they also need wide beam coverage capabilities. Currently, one solution to meet these communication tasks is to install different antennas in the system, but this inevitably increases space requirements. As modern wireless communication systems develop towards compactness and integration, there is an urgent need to develop a dual-frequency polarized pattern diversity antenna that can support V2S and V2N communication in two corresponding frequency bands within a single compact aperture, while also possessing wide coverage capabilities. Summary of the Invention

[0003] The purpose of this invention is to provide a dual-frequency polarized pattern diversity antenna, the antenna comprising: a first dielectric substrate and a second dielectric substrate; A square patch is disposed on the upper surface of the first dielectric substrate. The geometric center of the square patch coincides with the geometric center of the first dielectric substrate. Four rectangular slots are symmetrically disposed at the four corners of the square patch. The upper surface of the second dielectric substrate is provided with a slit resonant ring and a microstrip transmission line. One end of the microstrip transmission line is connected to the slit resonant ring, and the other end is provided with a power supply port. A metal floor is also provided on the lower surface of the second dielectric substrate. The lower surface of the first dielectric substrate and the upper surface of the second dielectric substrate are tightly overlapped without any air gaps in between. The square patch and the slotted resonant ring are distributed in upper and lower layers, and are misaligned in the horizontal plane.

[0004] Furthermore, the cleavage resonant ring is rectangular, with the long side of the cleavage resonant ring closest to the edge of the second dielectric substrate as the upper long side, a cleavage is provided at the center of the upper long side, and the lower long side is connected to one end of the microstrip transmission line at a position slightly to the left of the center.

[0005] Furthermore, the microstrip transmission line includes: stub one, stub two, stub three, stub four, stub five and stub six (12). One end of branch 1 is connected to a resonant ring with a gap. The other end of branch 1 is perpendicularly connected to one end of branch 2. The other end of branch 2 is perpendicularly connected to one end of branch 3. Branch 1 and branch 3 are located on opposite sides of the branch. The other end of branch 3 is perpendicularly connected to one end of branch 4. Branch 2 and branch 4 are located on the same side of branch 3. The other end of branch 4 is perpendicularly connected to one end of branch 5. Branch 5 and branch 3 are located on opposite sides of branch 4. The other end of branch 5 is perpendicularly connected to one end of branch 6. Branch 6 and branch 4 are located on opposite sides of branch 5. The other end of branch 6 is provided with a power supply port.

[0006] Furthermore, the thickness h1 of the first dielectric substrate is 0.8 mm; the thickness h2 of the second dielectric substrate is 3 mm. Both the first and second dielectric substrates are made of F4B, with a relative permittivity of 2.2 and a loss tangent of 0.0009.

[0007] Furthermore, the horizontal misalignment of the square patch and the split resonator ring results in a horizontal distance d4 between the lower long side of the split resonator ring and the near side of the square patch, which is 14.61 mm.

[0008] Furthermore, the side length of the square patch is 58.1 mm; The vertical distance d1 from the rectangular groove to the square patch is 10.78 mm; the length L2 of the rectangular groove is 21.1 mm, and the width W2 is 1.5 mm.

[0009] Furthermore, the crack length d2 of the crack resonator is 5.6 mm, and the length L3 from the crack to the short side of the crack resonator is 9 mm; The short side length W3 of the cracked resonator is 20mm, the long side length L4 is 23.6mm, and the width of the four sides of the cracked resonator W4 is 1.6mm.

[0010] Furthermore, the width L5 of branch one is 2.2 mm and the length W5 is 3.3 mm; the length L6 of branches two and four is 17.4 mm and the width W6 is 1.6 mm; the width L7 of branch five is 2.2 mm and the length W7 is 3.6 mm. The gap d3 between branch node 2 and branch node 4 is 1.1 mm.

[0011] Because of the adoption of the above technical solution, the present invention has the following advantages: 1. This application can effectively excite the circular polarization characteristics of the dual-axis ratio point in the low-frequency band through the magnetic coupling effect between the split resonant ring and the square patch. The antenna has good axis ratio beam performance in the low-frequency band. The implementation method is simple and effective, which can enable the wireless signal coverage to be wide and is suitable for the needs of V2S communication scenarios.

[0012] 2. This application modifies and optimizes the radiation pattern and performance of the antenna in the high-frequency band by loading a rectangular slot on a square patch. The antenna has a good quasi-omnidirectional radiation pattern in the high-frequency band, which enables the wireless signal to have a wide coverage range and is suitable for the needs of V2N communication scenarios.

[0013] 3. The dual-frequency polarized pattern diversity antenna proposed in this application can be applied to both V2S and V2N communication scenarios, and the antenna is small in size, low in profile, and simple in structure.

[0014] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0015] The accompanying drawings of this invention are described below.

[0016] Figure 1 This is a 3D structural schematic diagram of the dual-frequency antenna of the present invention; Figure 2 This is a top view of the dual-frequency antenna of the present invention; Figure 3 This is a dimensional diagram of the square patch in the dual-frequency antenna of the present invention; Figure 4 This is a dimensional diagram of the slotted resonator ring in the dual-frequency antenna of the present invention; Figure 5 This is a dimensional diagram of the microstrip transmission line in the dual-frequency antenna of this invention; Figure 6 This is a schematic diagram of the S-parameter curve and axial ratio curve of the dual-frequency antenna of the present invention; Figure 7 This is a schematic diagram of the axial ratio beamform of the dual-frequency antenna of the present invention in the low-frequency band; Figure 8 This is the 3D radiation pattern of the dual-frequency antenna of the present invention in the low-frequency band; Figure 9 This is the 3D radiation pattern of the dual-frequency antenna of the present invention in the high-frequency band; Figure 10 This is a diagram showing the achievable gain curves of the dual-band antenna of the present invention in the low-frequency and high-frequency bands.

[0017] In the figure: 1-square patch; 2-slit resonant ring; 3-microstrip transmission line; 4-metal ground plane; 5-first dielectric substrate 1; 6-second dielectric substrate 2; 7-stub 1; 8-stub 2; 9-stub 3; 10-stub 4; 11-stub 5; 12-stub 6. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of the embodiments of the present invention, it should be noted that unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. 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 an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0020] A dual-frequency polarization pattern diversity antenna, such as Figures 1 to 5 As shown, the antenna includes: a first dielectric substrate 5 and a second dielectric substrate 6; A square patch 1 is provided on the upper surface of the first dielectric substrate 5. The geometric center of the square patch 1 coincides with the geometric center of the first dielectric substrate. Four rectangular slots are symmetrically provided at the four corners of the square patch 1. The upper surface of the second dielectric substrate 6 is provided with a slit resonant ring 2 and a microstrip transmission line 3. One end of the microstrip transmission line 3 is connected to the slit resonant ring 2, and the other end is provided with a power supply port. A metal floor 4 is also provided on the lower surface of the second dielectric substrate 6. The lower surface of the first dielectric substrate 5 and the upper surface of the second dielectric substrate 6 are tightly overlapped without any air gaps in between. The square patch 1 and the cracked resonant ring 2 are distributed in upper and lower layers and are misaligned in the horizontal plane.

[0021] In one embodiment, the cleavage resonant ring 2 is rectangular, with the long side of the cleavage resonant ring 2 closest to the edge of the second dielectric substrate 6 as the upper long side, a cleavage is provided at the center of the upper long side, and the lower long side is connected to one end of the microstrip transmission line 3 at a position slightly to the left of the center.

[0022] In one embodiment, the microstrip transmission line 3 includes: stub 1 7, stub 2 8, stub 3 9, stub 4 10, stub 5 11 and stub 6 12; One end of spur 1 7 is connected to the resonant ring 2. The other end of spur 1 7 is vertically connected to one end of spur 2 8. The other end of spur 2 8 is vertically connected to one end of spur 3 9. Spur 1 7 and spur 3 9 are located on opposite sides of spur 8. The other end of spur 3 9 is vertically connected to one end of spur 4 10. Spur 2 8 and spur 4 10 are located on the same side of spur 3 9. The other end of spur 4 10 is vertically connected to one end of spur 5 11. Spur 5 11 and spur 3 9 are located on opposite sides of spur 4 10. The other end of spur 5 11 is vertically connected to one end of spur 6 12. Spur 6 12 and spur 4 10 are located on opposite sides of spur 5 11. The other end of spur 6 12 is provided with a power supply port.

[0023] It should be noted that this antenna structure consists of two dielectric substrates. A slotted square patch is placed on the upper surface of the first dielectric substrate, while the split-ring resonator and microstrip transmission line are both placed on the upper surface of the second dielectric substrate. The microstrip transmission line is connected to the lower left side of the split-ring resonator for feeding. The metal ground plane is located on the lower surface of the second dielectric substrate. The antenna ultimately produces a dual-band effect, exhibiting circularly polarized radiation characteristics in the low-frequency band and a quasi-omnidirectional radiation pattern in the high-frequency band. It possesses excellent wide coverage capability and is suitable for applications in complex communication environments.

[0024] This antenna can generate circularly polarized radiation characteristics with a wide axial ratio beam in the low-frequency band, and exhibits two minimum axial ratio values ​​within the bandwidth, making it suitable for communication needs between vehicles and satellites. In the high-frequency band, it can generate a linearly polarized quasi-omnidirectional radiation pattern, suitable for communication needs between vehicles and wireless networks. The antenna proposed in this invention has the characteristics of small size, low profile, simple structure, and low cost.

[0025] The frequency and performance of its low-frequency circularly polarized band can be controlled by adjusting the distance d4 between the lower edge of the split resonator ring and the upper edge of the patch to control the intensity and corresponding frequency of the odd and even modes excited by magnetic coupling, while simultaneously adjusting the fundamental mode resonant frequency of the square patch. Furthermore, by loading four rectangular slots onto the square patch, the higher-order mode resonant frequencies of the square patch in the high-frequency band can be controlled, thereby optimizing the radiation pattern and related performance in this band.

[0026] Simulation verification: A dual-frequency polarization pattern diversity antenna, such as Figures 1 to 5 As shown in the table below, the dimensions of each parameter are as follows: parameter Dimensions (mm) <![CDATA[L1]]> 58.1 <![CDATA[L2]]> 21.1 <![CDATA[L3]]> 9 <![CDATA[L4]]> 23.6 <![CDATA[L5]]> 2.2 <![CDATA[L6]]> 17.4 <![CDATA[L7]]> 2.2 <![CDATA[W1]]> 58.1 <![CDATA[W2]]> 1.5 <![CDATA[W3]]> 20 <![CDATA[W4]]> 1.6 <![CDATA[W5]]> 3.3 <![CDATA[W6]]> 1.6 <![CDATA[W7]]> 3.6 <![CDATA[h1]]> 0.8 <![CDATA[h2]]> 3 <![CDATA[d1]]> 10.78 <![CDATA[d2]]> 5.6 <![CDATA[d3]]> 1.1 <![CDATA[d4]]> 14.61 Both the first and second dielectric substrates are made of F4B, with a relative permittivity of 2.2 and a loss tangent of 0.0009.

[0027] Based on the above parameters, the reflection coefficient of the designed dual-frequency polarized pattern diversity antenna was simulated and analyzed using HFSS. The analysis results are as follows: like Figure 6 As shown, the port reflection coefficient |S| of a dual-frequency polarized pattern diversity antenna is... 11 Simulation curves. Simulation results show that the antenna can achieve dual-band radiation characteristics. Its -10dB impedance bandwidth in the low-frequency band is 1.55-1.61GHz, with a corresponding 3dB axial ratio bandwidth range of 1.55-1.60GHz and a corresponding fractional bandwidth of 3.2%. In addition, the antenna's -10dB impedance bandwidth in the high-frequency band is 3.21-3.33GHz.

[0028] Figure 7 The axial ratio beamform of a dual-frequency polarization pattern diversity antenna in the low-frequency band is shown. Figure 8 This is the 3D radiation pattern of a dual-frequency polarized diversity antenna in the low-frequency band. The results show that the axial ratio beam of the antenna in the xoz plane is above 145° within a 3dB axial ratio bandwidth, indicating that the antenna has good circular polarization radiation characteristics over a large angle range and has the ability to provide wide signal coverage.

[0029] Figure 9 This is the 3D radiation pattern of a dual-frequency polarized pattern diversity antenna in the high-frequency band. The result indicates that the antenna has a quasi-omnidirectional radiation pattern in the xoy plane, providing wide signal coverage.

[0030] Figure 10 This shows the achievable gain curves for a dual-frequency polarized pattern diversity antenna in the low-frequency and high-frequency bands. The results indicate that the antenna has an achievable gain of 6.13 dBic at low frequencies and 5.5 dBi at high frequencies.

[0031] The compact dual-frequency polarized pattern diversity antenna proposed in this application can achieve dual-band operation in a simple and effective manner. This antenna exhibits circular polarization radiation characteristics with a dual-axis ratio point in the low-frequency band and linear polarization radiation in the high-frequency band; simultaneously, it possesses wide beam coverage characteristics in both frequency bands while maintaining a low profile height and good radiation performance.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A dual-frequency polarization pattern diversity antenna, characterized in that, The antenna includes: a first dielectric substrate (5) and a second dielectric substrate (6); A square patch (1) is provided on the upper surface of the first dielectric substrate (5). The geometric center of the square patch (1) coincides with the geometric center of the first dielectric substrate. Four rectangular grooves are symmetrically provided at the four corners of the square patch (1). The upper surface of the second dielectric substrate (6) is provided with a cleavage resonant ring (2) and a microstrip transmission line (3). One end of the microstrip transmission line (3) is connected to the cleavage resonant ring (2), and the other end is provided with a power supply port. A metal floor (4) is also provided on the lower surface of the second dielectric substrate (6). The lower surface of the first dielectric substrate (5) and the upper surface of the second dielectric substrate (6) are tightly overlapped without any air gaps in between. The square patch (1) and the cracked resonant ring (2) are distributed in upper and lower layers and are misaligned in the horizontal plane.

2. The dual-frequency polarization pattern diversity antenna as described in claim 1, characterized in that, The cleavage resonant ring (2) is rectangular, with the long side of the cleavage resonant ring (2) that is close to the edge of the second dielectric substrate (6) as the upper long side. A cleavage is provided at the center of the upper long side, and the lower long side is connected to one end of the microstrip transmission line (3) at a position slightly to the left of the center.

3. The dual-frequency polarization pattern diversity antenna as described in claim 1, characterized in that, The microstrip transmission line (3) includes: stub one (7), stub two (8), stub three (9), stub four (10), stub five (11) and stub six (12). One end of branch 1 (7) is connected to the resonant ring (2), the other end of branch 1 (7) is vertically connected to one end of branch 2 (8), the other end of branch 2 (8) is vertically connected to one end of branch 3 (9), branch 1 (7) and branch 3 (9) are located on both sides of branch (8), the other end of branch 3 (9) is vertically connected to one end of branch 4 (10), branch 2 (8) and branch 4 (10) are located on the same side of branch 3 (9), the other end of branch 4 (10) is vertically connected to one end of branch 5 (11), branch 5 (11) and branch 3 (9) are located on both sides of branch 4 (10), the other end of branch 5 (11) is vertically connected to one end of branch 6 (12), branch 6 (12) and branch 4 (10) are located on both sides of branch 5 (11), and the other end of branch 6 (12) is provided with a power supply port.

4. The dual-frequency polarization pattern diversity antenna as described in claim 1, characterized in that, The thickness h1 of the first dielectric substrate (5) is 0.8 mm; the thickness h2 of the second dielectric substrate (6) is 3 mm. The first dielectric substrate (5) and the second dielectric substrate (6) are both made of F4B, with a relative permittivity of 2.2 and a loss tangent of 0.0009.

5. The dual-frequency polarization pattern diversity antenna as described in claim 2, characterized in that, The horizontal misalignment of the square patch (1) and the split resonator (2) results in a horizontal distance d4 from the lower long side of the split resonator (2) to the near side of the square patch (1), which is 14.61 mm.

6. The dual-frequency polarization pattern diversity antenna as described in claim 1, characterized in that, The side length of the square patch (1) is 58.1 mm; The vertical distance d1 from the rectangular groove to the square patch (1) is 10.78 mm; the length L2 of the rectangular groove is 21.1 mm and the width W2 is 1.5 mm.

7. The dual-frequency polarization pattern diversity antenna as described in claim 2, characterized in that, The crack length d2 of the cracked resonant ring (2) is 5.6 mm, and the length L3 from the crack to the short side of the cracked resonant ring (2) is 9 mm. The short side length W3 of the cracked resonant ring (2) is 20mm, the long side length L4 is 23.6mm, and the width W4 of the four sides of the cracked resonant ring (2) is 1.6mm.

8. The dual-frequency polarization pattern diversity antenna as described in claim 3, characterized in that, Branch 1 (7) has a width L5 of 2.2 mm and a length W5 of 3.3 mm; Branch 2 (8) and Branch 4 (10) have a length L6 of 17.4 mm and a width W6 of 1.6 mm; Branch 5 (11) has a width L7 of 2.2 mm and a length W7 of 3.6 mm. The gap d3 between branch 2 (8) and branch 4 is 1.1 mm.

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