A low-coupling dual-frequency dual-radiation pattern antenna

Abstract

The present invention discloses a low-coupling dual-frequency dual-radiation pattern antenna, which includes a first dielectric plate, a second dielectric plate, and a metal ground plate. The first dielectric plate is composed of a first substrate, an octagonal patch, and a parasitic patch. The octagonal patch and the parasitic patch are placed on the upper surface of the first substrate, and the octagonal patch is provided with a ring-shaped gap. The second dielectric plate is composed of a second substrate and a circular patch. The circular patch is placed on the upper surface of the second substrate, and the circular patch is provided with an annular gap. The metal ground plate is connected to the first dielectric plate through a first probe and to the second dielectric plate through a second probe. The present invention integrates an antenna with circularly polarized normal radiation characteristics and an antenna with linearly polarized conical radiation performance under the same caliber, greatly reducing the space occupied by the antenna and realizing the dual-band, dual-polarization, and dual-radiation pattern characteristics of the antenna.

Description

Technical Field

[0001] The invention relates to a low-coupling dual-frequency dual-radiation pattern antenna, belonging to the technical field of wireless communications. Background Art

[0002] In recent years, with the rapid development of the electronics industry and communication technology, drone technology has also appeared more widely in the civilian field, such as earthquake relief, intelligent cruising, urban aerial photography, etc.; but the earliest drones were used in the military field to scout enemy situations, transmit intelligence, etc. Due to their large size, drones have not really become popular in the public eye.

[0003] Drone positioning, navigation, and real-time communication with the ground rely entirely on navigation and communication antennas. Traditional drone navigation antennas use helical antennas because they generate circularly polarized waves. Circularly polarized antennas can receive incoming waves of any polarization, and their radiated waves can also be received by antennas of any polarization, providing exceptional stability for navigation. However, helical antennas are three-dimensional spiral structures, so they occupy a large space, significantly limiting the miniaturization of drones.

[0004] Typically, antennas used for communications are linearly polarized, and they are also required to maintain a low profile to minimize the space occupied by the airborne antenna. Therefore, achieving the desired performance while further reducing the space occupied by the airborne antenna presents a design challenge.

[0005] The information disclosed in this background section is only intended to enhance understanding of the overall background of the invention and should not be considered as an admission or any form of suggestion that the information constitutes the prior art already known to a person of ordinary skill in the art. Summary of the Invention

[0006] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a low-coupling dual-band dual-radiation pattern antenna to solve the problems of traditional UAV airborne antennas being too large and the axial ratio bandwidth of navigation antennas being narrow. The designed antenna has different polarization modes and radiation pattern forms in different frequency bands (low frequency: circularly polarized normal radiation, high frequency: linearly polarized conical radiation); at the same time, the two polarization antennas are integrated together to reduce the space occupied by traditional UAV airborne antennas.

[0007] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0008] The present invention provides a low-coupling dual-frequency dual-radiation pattern antenna, the antenna comprising a first dielectric plate, a second dielectric plate and a metal ground plate;

[0009] The first dielectric plate is composed of a first substrate, an octagonal patch and a parasitic patch, wherein the octagonal patch and the parasitic patch are placed on the upper surface of the first substrate, and a ring-shaped gap is opened on the octagonal patch;

[0010] The second dielectric plate is composed of a second substrate and a circular patch, the circular patch is placed on the upper surface of the second substrate, and an annular gap is opened on the circular patch;

[0011] The metal ground plate is connected to the first dielectric plate through a first probe and is connected to the second dielectric plate through a second probe.

[0012] Furthermore, the first substrate is square;

[0013] The number of the octagonal patch is one, and the patch is placed at the center of the upper surface of the first substrate;

[0014] The number of the parasitic patches is 4 and they are distributed around the periphery of the upper surface of the first substrate.

[0015] Furthermore, a first feeding hole and a short-circuit hole are provided on the outer side of the octagonal patch along the outer side of the slit.

[0016] The antenna further includes a short-circuit post, the upper end of which passes through the first substrate and is connected to the octagonal patch through a short-circuit hole, and the lower end of which is connected to the metal ground plate;

[0017] The upper end of the first probe penetrates the first substrate and is connected to the octagonal patch through the first feeding hole, and the lower end is fixed to the metal ground plate.

[0018] Furthermore, a square groove is provided around the first feeding hole, and the first feeding hole is located at the center of the square groove.

[0019] Further, the octagonal patch is divided into first, second, third and fourth quadrants according to a rectangular coordinate system, and the first, second, third and fourth quadrants are rotated clockwise about the center of the octagonal patch;

[0020] The octagonal patch is composed of a square patch with four corners cut off, and the shape of the cut corners is an isosceles right triangle, wherein the cut angles of the first and third quadrants are equal in size, the cut angles of the second and fourth quadrants are equal in size, and the length of the cut angle sides of the first and third quadrants are not equal to the length of the cut angle sides of the second and fourth quadrants.

[0021] Furthermore, the antenna also includes a support, and a support hole that matches the support is opened around the first substrate. The upper end of the support passes through the first substrate and extends above the first substrate, and the lower end is connected to the metal ground plate.

[0022] Furthermore, the second substrate is circular;

[0023] A circular patch is placed at the center of the upper surface of the second substrate, and a second feeding hole is opened at the center of the circular patch.

[0024] Furthermore, the upper end of the second probe penetrates the second substrate and is connected to the circular patch through the second feeding hole, and the lower end is fixed to the metal ground plate.

[0025] Furthermore, the first dielectric plate, the second dielectric plate and the metal ground plate are parallel to each other, the second dielectric plate is located above the metal ground plate, and the first dielectric plate is located above the second dielectric plate.

[0026] Furthermore, the dielectric constant of the first dielectric plate is 4.4, and the dielectric constant of the second dielectric plate is 4.4.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention integrates an antenna with circularly polarized normal radiation characteristics and an antenna with linearly polarized conical radiation characteristics by rationally arranging the structures of the first dielectric plate and the second dielectric plate, thereby greatly improving space utilization and achieving the dual-band, dual-polarization, and dual-radiation pattern characteristics of the antenna.

[0029] For the low-frequency circularly polarized normal pattern antenna, an octagonal patch is formed by cutting two pairs of isosceles right triangles of different sizes from the two diagonal lines of the square patch to achieve circularly polarized radiation. On the one hand, four rectangular parasitic patches are introduced around the octagonal patch to widen the antenna's axial ratio bandwidth. On the other hand, square slots are opened around the first feed hole to obtain compensation capacitance, thereby achieving broadband matching performance of the patch. A slit is set in the center of the octagonal patch, which is equivalent to a capacitor C. At the same time, three short-circuit posts are introduced around the slit, which are equivalent to an inductor L. This capacitor C and inductor L introduce a new resonant frequency point for the antenna, thereby widening the antenna's impedance bandwidth.

[0030] For high-frequency linearly polarized conical antennas, an annular gap is introduced in the circular patch. This not only compensates for the additional inductance caused by the height difference between the second dielectric plate and the floor, achieving broadband matching, but also enables the high-frequency linearly polarized antenna to produce conical radiation performance. Furthermore, the circular patch has a certain coupling effect with the octagonal patch placed on the first dielectric plate, which can produce a capacitive effect and also compensate for the additional inductance, achieving broadband matching. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a three-dimensional structural diagram of a low-coupling dual-band dual-radiation pattern antenna.

[0032] Figure 2This is a main view of a low-coupling dual-band dual-radiation pattern antenna;

[0033] Figure 3 is a top view of the first dielectric plate;

[0034] Figure 4 is a top view of the second dielectric plate;

[0035] Figure 5 It is a full-band return loss simulation and measurement results of a low-coupling dual-band dual-radiation pattern antenna;

[0036] Figure 6 is the axial ratio diagram of the low-frequency circularly polarized normal pattern antenna;

[0037] Figure 7 It is a simulation and measurement result of the isolation between the two feeding ports of a low-coupling dual-band dual-radiation pattern antenna in the full frequency band;

[0038] Figure 8 The left-hand circular polarization gain (GainLHCP) and right-hand circular polarization gain (GainRHCP) of the low-frequency circularly polarized normal pattern antenna at 2.4GHz are respectively at Phi=0° ( xoz Simulation and measurement results of the surface);

[0039] Figure 9 The left-hand circular polarization gain (GainLHCP) and right-hand circular polarization gain (GainRHCP) of the low-frequency circularly polarized normal pattern antenna at 2.4GHz are respectively at Phi=90° ( yoz Simulation and measurement results of the surface);

[0040] Figure 10 The following are the simulation and measurement results of the gain variation curve of the low-frequency circularly polarized normal pattern antenna with respect to frequency;

[0041] Figure 11 The simulation and measurement results of the gain variation curve of the high-frequency linear polarization conical radiation pattern antenna with frequency;

[0042] Figure 12 The Phi direction gain component (GainPhi) of the high frequency linear polarization conical pattern antenna at 5.8 GHz is at Phi=0°( xoz Simulation and measurement results of the surface);

[0043] Figure 13 Theta direction gain component (GainTheta) of the high frequency linear polarization conical pattern antenna at 5.8 GHz at Phi = 0° ( xoz Simulation and measurement results of the surface);

[0044] Figure 14The Phi direction gain component (GainPhi) of the high frequency linear polarization conical pattern antenna at 5.8 GHz is at Phi=90° ( yoz Simulation and measurement results of the surface);

[0045] Figure 15 Theta direction gain component (GainTheta) of the high frequency linear polarization conical pattern antenna at 5.8 GHz at Phi = 90° ( yoz Simulation and measurement results of the surface);

[0046] Figure 16 This is the comparison result of the axial ratio simulation with and without parasitic patches;

[0047] Figure 17 Is loaded with inductance, capacitance and not loaded with inductance, capacitance S 11 Simulation comparison chart;

[0048] In the figure: 1. First dielectric plate; 2. Second dielectric plate; 3. Metal ground plate; 4. First substrate; 5. Octagonal patch; 6. Parasitic patch; 7. Ring-shaped gap; 8. Second substrate; 9. Circular patch; 10. Annular gap; 11. First probe; 12. Second probe; 13. First feeding hole; 14. Short-circuit hole; 15. Short-circuit column; 16. Square slot; 17. Support; 18. Support hole; 19. Second feeding hole. DETAILED DESCRIPTION

[0049] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Example

[0050] This embodiment provides a low-coupling dual-frequency dual-radiation pattern antenna, such as Figure 1-4 As shown, the antenna includes a first dielectric plate 1, a second dielectric plate 2 and a metal ground plate 3.

[0051] The first dielectric plate 1 is composed of a first substrate 4, an octagonal patch 5 and a parasitic patch 6. The octagonal patch 5 and the parasitic patch 6 are placed on the upper surface of the first substrate 4, and a ring-shaped gap 7 is opened on the octagonal patch 5.

[0052] The second dielectric plate 2 is composed of a second substrate 8 and a circular patch 9 . The circular patch 9 is placed on the upper surface of the second substrate 8 , and an annular gap 10 is formed on the circular patch 9 .

[0053] The metal ground plate 3 is connected to the first dielectric plate 1 through a first probe 11 and is connected to the second dielectric plate 2 through a second probe 12 .

[0054] The technical concept of the present invention is as follows: by placing an octagonal patch 5 and a parasitic patch 6 on a first substrate 4, the first dielectric plate 1 is used as a low-frequency circularly polarized normal pattern antenna; by placing a circular patch 9 on a second substrate 8, the second dielectric plate 2 is used as a high-frequency linearly polarized conical pattern antenna, and in combination with a metal ground plate 3, the dual-band, dual-polarization, and dual-radiation pattern characteristics of the antenna are realized.

[0055] In the application of drone equipment, the built-in antenna of the drone generally uses two frequency bands, one for navigation and the other for communication. A circularly polarized directional beam antenna is used in the navigation band, and a linearly polarized conical beam antenna is used in the communication band. The designed 2.4GHz left-hand circularly polarized normal radiation characteristic antenna and the 5.8GHz linearly polarized conical radiation characteristic antenna do not interfere with each other due to their different polarization modes and occupying different frequency bands. This is a good choice for drone airborne terminal antennas. The antenna provided in this embodiment is mainly used to solve the problems of "oversized airborne antenna" and "communication interference" in drones.

[0056] like Figure 3 As shown, the first substrate 4 is a square with a side length of 115 mm. An octagonal patch 5 is placed at the center of the upper surface of the first substrate 4. Four parasitic patches 6 are distributed around the upper surface of the first substrate 4. The four parasitic patches 6 are exactly the same size and shape. Each parasitic patch 6 is 41 mm long and 12 mm wide.

[0057] The inner diameter of the ring-shaped gap 7 on the octagonal patch 5 is 29 mm, the outer diameter is 31 mm, and the arc length of the gap at the unclosed portion is 3 mm.

[0058] Taking the center of the octagonal patch 5 as the quadrant center, the octagonal patch 5 is divided into the first, second, third and fourth quadrants according to the rectangular coordinate system. The first quadrant is located in the upper right, and the first, second, third and fourth quadrants rotate clockwise about the quadrant center.

[0059] The octagonal patch 5 is composed of a square patch with four corners cut off, and the shape of the cut corners is an isosceles right triangle, wherein the cut angles of the first and third quadrants are equal in size, the cut angles of the second and fourth quadrants are equal in size, and the length of the cut angle sides of the first and third quadrants are not equal to the length of the cut angle sides of the second and fourth quadrants.

[0060] In this embodiment, the length of the right angle side of the isosceles right triangle cut by the first and third quadrants is 11 mm, and the length of the right angle side of the isosceles right triangle cut by the second and fourth quadrants is 5 mm.

[0061] A first feeding hole 13 and a short-circuit hole 14 are provided on the outer side of the ring-shaped gap 7 along the upper edge of the octagonal patch 5 . The diameter of the first feeding hole 13 is 1.32 mm, and the diameter of the short-circuit hole 14 is 2 mm.

[0062] A square slot 16 is formed around the first feeding hole 13, and the first feeding hole 13 is located at the center of the square slot 16. The inner side length of the square slot 16 is 6.7 mm, and the outer side length is 7.7 mm.

[0063] Because there is an air gap between the first substrate 4 and the metal ground plate 3, additional inductance is introduced into the feeding coaxial part. The purpose of providing the square slot 16 is to obtain compensation capacitance, thereby achieving broadband matching of the antenna.

[0064] like Figure 2 As shown, the upper end of the first probe 11 passes through the first substrate 4 and is connected to the octagonal patch 5 through the first feeding hole 13, and the lower end is fixed to the metal ground plate 3.

[0065] The antenna further includes a short-circuit post 15 , the upper end of which passes through the first substrate 4 and is connected to the octagonal patch 5 via the short-circuit hole 14 , and the lower end of which is connected to the metal ground plate 3 ;

[0066] The antenna further includes a support 17 . A support hole 18 matching with the support 17 is formed on the periphery of the first substrate 4 . The diameter of the support hole 18 is 7.2 mm.

[0067] The upper end of the support 17 passes through the first substrate 4 and extends above the first substrate 4 , and the lower end is connected to the metal ground plate 3 .

[0068] like Figure 4 As shown, the second substrate 8 is circular with a diameter of 20 mm.

[0069] A circular patch 9 is placed at the center of the upper surface of the second substrate 8, and a second feed hole 19 is formed at the center of the circular patch 9. The diameter of the circular patch 9 is 11 mm, and the diameter of the second feed hole 19 is 1.32 mm. The inner diameter of the annular gap 10 is 5 mm, and the outer diameter is 6 mm.

[0070] like Figure 2 As shown, the upper end of the second probe 12 passes through the second substrate 8 and is connected to the circle through the second feeding hole 19 , and the lower end is fixed to the metal ground plate 3 .

[0071] The first dielectric plate 1 and the second dielectric plate 2 are parallel to the metal ground plate 3. The second dielectric plate 2 is located above the metal ground plate 3, and the first dielectric plate 1 is located above the second dielectric plate 2. The dielectric constant of the first dielectric plate 1 is 4.4, and the dielectric constant of the second dielectric plate 2 is 4.4.

[0072] The thickness of the first substrate 4 is 1 mm, the thickness of the second substrate 8 is 0.5 mm, the vertical height between the first substrate 4 and the metal ground plate 3 is 10 mm, and the vertical height between the second substrate 8 and the metal ground plate 3 is 6.5 mm.

[0073] The antenna designed in this embodiment is suitable for mobile satellite communication, space communication and other working equipment.

[0074] An octagonal patch 5 is placed on the first substrate 4 to achieve circularly polarized radiation performance; the purpose of introducing four parasitic patches 6 is to stimulate a new resonant mode for improving the axial ratio bandwidth; at the same time, a ring-shaped gap 7 is opened on the octagonal patch 5, which is equivalent to introducing a capacitive effect, which resonates with the inductive effect brought by the above-mentioned short-circuit column 15, thereby widening the impedance bandwidth.

[0075] A circular patch 9 is placed on the second substrate 8. A second probe is used to feed current directly at the center of the circular patch 9. A closed annular gap 10 is also introduced. This gap serves the same purpose as the square slot 16 described above: to provide compensation capacitance for broadband antenna matching. Furthermore, this gap is also introduced to generate a conical radiation beam, achieving linearly polarized conical radiation characteristics.

[0076] Depend on Figure 5 It can be seen that this antenna has two resonant frequency bands, and its low-frequency and high-frequency impedance bandwidths (return loss <-10dB) are 45.37% (1.67GHz-2.55GHz) and 14.83% (5.43-6.3GHz) respectively. S 11 It represents the return loss of the low-frequency circular polarization normal pattern antenna feed port, S 22 Indicates the return loss of the feed port of a high-frequency linearly polarized conical antenna.

[0077] like Figure 7 The figure shows the simulation and measurement results of the isolation between the two feeding ports of the antenna. It can be seen from the figure that in the low frequency band (1.5GHz-3GHz), the overall isolation is less than -20dB, which has excellent isolation performance; in the high frequency band (5GHz-7GHz), the isolation is slightly worse, but overall less than -12.2dB, which also has good isolation performance.

[0078] In addition, if Figure 6 The 3dB axial ratio bandwidth of the circularly polarized antenna in the low-frequency band is 12.45% (2.26GHz-2.56GHz). It can be seen that the low-frequency circularly polarized normal radiation pattern antenna has good circular polarization performance.

[0079] Figure 8-9 The figure shows the simulated and measured radiation patterns of the antenna at 2.4 GHz. The figure shows that the circularly polarized antenna exhibits good left-hand circular polarization performance, with the main radiation direction being normal and the difference between the main and cross-polarization levels being 20.75 dB.

[0080] Figure 10It shows that the circularly polarized antenna in the low frequency band can achieve a gain greater than 6.2dBi in the passband, which means that a relatively high circular polarization gain can be achieved.

[0081] Figure 12-13 It shows that at 5.8GHz, the Phi direction gain component (GainPhi) and the Theta direction gain component (GainTheta) are at Phi = 0° ( xoz Simulation and measurement results of radiation patterns (surface); and Figure 14-15 It shows that at 5.8GHz, the Phi direction gain component (GainPhi) and the Theta direction gain component (GainTheta) are at Phi = 90° ( yoz The simulation and measurement results of the radiation pattern (surface) show that the theta direction is the main polarization direction, and this high-frequency antenna has good linearly polarized conical radiation characteristics.

[0082] Figure 11 It shows that the linearly polarized antenna in the high frequency band can achieve a gain greater than 5.2dBi within the passband, which means that a relatively high linear polarization gain can be achieved.

[0083] This invention fully utilizes space resources, integrating dual-band, dual-radiation antennas into a unified aperture and significantly improving antenna gain. The low-frequency circularly polarized normal-pattern antenna operates in the 2.26-2.56 GHz radiation band, while the high-frequency linearly polarized conical-pattern antenna operates in the 5.43-6.3 GHz radiation band.

[0084] For the design of a low-frequency circularly polarized normal pattern antenna, two pairs of isosceles right triangles of different sizes are cut off from the two diagonal lines of the square patch, thereby exciting two mutually perpendicular resonant modes at the same frequency point, thereby achieving circularly polarized radiation. The present invention first introduces four rectangular parasitic patches around the octagonal patch, which introduces a new resonant mode and broadens the axial ratio bandwidth of the antenna. Figure 16 The axial ratio simulation results with and without the parasitic patch are compared. The simulation results show that the addition of the parasitic patch introduces a new axial ratio null in the antenna. The axial ratio bandwidth (AR ≤ 3 dB) is widened from 4.26% (2.3 GHz to 2.4 GHz) to 12.45% (2.26 GHz to 2.56 GHz).

[0085] Secondly, the present invention improves the impedance bandwidth of the low-frequency circularly polarized normal pattern antenna. The impedance bandwidth of traditional patch antennas is very narrow. In order to improve its bandwidth, we set an air gap of a certain thickness between the first substrate and the floor, which introduces additional inductance at the feeding coaxial part. In order to compensate for this part of the additional inductance, the capacitive coupling feeding technology is adopted. By opening a square slot around the first feeding hole, a compensation capacitor is obtained, thereby achieving the broadband matching performance of the patch; on the other hand, a ring-shaped gap is set in the center of the octagonal patch, which is equivalent to a capacitor C. At the same time, three short-circuit columns are introduced around the ring-shaped gap, which can be equivalent to an inductor L. This capacitor C and inductor L introduce a new resonant frequency point for the antenna, thereby broadening the impedance bandwidth of the antenna. Figure 17 The results of loaded inductance, capacitance and unloaded inductance, capacitance are given. S 11 |Simulation comparison chart: Before the inductor and capacitor are loaded, the impedance bandwidth of the antenna is 20.69% (2.08GHz-2.56GHz). When the inductor and capacitor are loaded at the same time, the impedance bandwidth is 45.37% (1.67GHz-2.55GHz).

[0086] In the design of the high-frequency linearly polarized conical antenna, a circular gap is clearly visible in the circular patch. This gap serves two primary purposes: first, it compensates for the additional inductance introduced by the height difference between the second dielectric plate and the floor, achieving broadband matching; second, it enables the high-frequency linearly polarized antenna to produce conical radiation performance. Furthermore, the circular patch has a certain coupling effect with the octagonal patch placed on the first dielectric plate, generating a capacitive effect that also compensates for the additional inductance and achieves broadband matching.

[0087] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the 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 limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0088] 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 technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A low-coupling dual-band dual-radiation pattern antenna, characterized in that: The antenna comprises a first dielectric plate (1), a second dielectric plate (2) and a metal ground plate (3). The first dielectric plate (1) is composed of a first substrate (4), an octagonal patch (5) and a parasitic patch (6); the octagonal patch (5) and the parasitic patch (6) are placed on the upper surface of the first substrate (4), and a ring-shaped gap (7) is provided on the octagonal patch (5); The second dielectric plate (2) is composed of a second substrate (8) and a circular patch (9), wherein the circular patch (9) is placed on the upper surface of the second substrate (8), and an annular gap (10) is provided on the circular patch (9); The metal ground plate (3) is connected to the first dielectric plate (1) via a first probe (11), and is connected to the second dielectric plate (2) via a second probe (12); A first feeding hole (13) and a short-circuit hole (14) are provided on the outer side of the octagonal patch (5) along the rim-shaped gap (7). The antenna further comprises a short-circuit post (15), the upper end of the short-circuit post (15) passing through the first substrate (4) and connected to the octagonal patch (5) via the short-circuit hole (14), and the lower end of the short-circuit post (15) is connected to the metal ground plate (3); The upper end of the first probe (11) passes through the first substrate (4) and is connected to the octagonal patch (5) through the first feed hole (13), and the lower end is fixed to the metal ground plate (3); A square slot (16) is provided around the first feeding hole (13), and the first feeding hole (13) is located at the center of the square slot (16).

2. The low-coupling dual-band dual-radiation pattern antenna according to claim 1, characterized in that: The first substrate (4) is square; The number of the octagonal patch (5) is one, and the patch is placed at the center of the upper surface of the first substrate (4); The number of the parasitic patches (6) is four, and they are distributed around the periphery of the upper surface of the first substrate (4).

3. The low-coupling dual-band dual-radiation pattern antenna according to claim 1, wherein: Dividing the octagonal patch (5) into first, second, third and fourth quadrants according to a rectangular coordinate system, wherein the first, second, third and fourth quadrants rotate clockwise about the center of the octagonal patch (5); The octagonal patch (5) is composed of a square patch with four corners cut off, and the shape of the cut corners is an isosceles right triangle, wherein the cut corners of the first and third quadrants are equal in size, the cut corners of the second and fourth quadrants are equal in size, and the length of the cut corner sides of the first and third quadrants are not equal to the length of the cut corner sides of the second and fourth quadrants.

4. The low-coupling dual-band dual-radiation pattern antenna according to claim 1, wherein: The antenna further comprises a support (17), and a support hole (18) cooperating with the support (17) is further provided on the periphery of the first substrate (4). The upper end of the support (17) passes through the first substrate (4) and extends above the first substrate (4), and the lower end is connected to the metal ground plate (3).

5. The low-coupling dual-band dual-radiation pattern antenna according to claim 1, wherein: The second substrate (8) is circular; A circular patch (9) is placed at the center of the upper surface of the second substrate (8), and a second feeding hole (19) is opened at the center of the circular patch (9).

6. The low-coupling dual-band dual-radiation pattern antenna according to claim 5, characterized in that: The upper end of the second probe (12) passes through the second substrate (8) and is connected to the circular patch (9) through the second feed hole (19), and the lower end is fixedly connected to the metal ground plate (3).

7. The low-coupling dual-band dual-radiation pattern antenna according to claim 1, wherein: The first dielectric plate (1), the second dielectric plate (2) and the metal grounding plate (3) are parallel to each other; the second dielectric plate (2) is located above the metal grounding plate (3); and the first dielectric plate (1) is located above the second dielectric plate (2).

8. The low-coupling dual-band dual-radiation pattern antenna according to claim 1, wherein: The dielectric constant of the first dielectric plate (1) is 4.4, and the dielectric constant of the second dielectric plate (2) is 4.4.

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