A high-gain broadband antenna based on resonant ring and back cavity structure

Abstract

The present invention provides a high-gain broadband antenna based on a resonant ring and back cavity structure. The main body of the antenna includes a stacked and fractal microstrip antenna, a curved reflector, a resonant ring, and a bowl-shaped back cavity structure. The curved reflector is formed by spraying conductive silver paste on the inner bottom surface of the bowl-shaped back cavity structure. The stacked and fractal microstrip antenna consists of two layers and is located within the bowl-shaped back cavity structure. The upper microstrip antenna is circular, and the radiating patch adopts a 4th-order iterated circular fractal structure. The bottom of the lower dielectric layer is copper-clad as a base plate, and air is used to fill the space between the two dielectric layers. The resonant ring is located on top of the bowl-shaped back cavity structure. The antenna operates in a frequency band of 5.61 GHz to 6.72 GHz, with a gain of 10.9 dBi to 14.6 dBi within this frequency range, with the highest gain at 5.7 GHz. The antenna has the advantages of simple structure, low cost, wide bandwidth, and high gain.

Description

Technical Field

[0001] The present invention belongs to the technical field of antennas, and in particular relates to a high-gain broadband antenna based on a resonant ring and a back cavity structure. Background Art

[0002] Antennas are indispensable functional devices in the field of wireless communications. Their main function is to complete the mutual conversion between guided waves and free space waves to achieve information exchange.

[0003] With the rapid development of science and technology, the requirements for transmission rate and communication capacity in current communication systems are becoming increasingly higher, which requires antennas to have broadband performance.

[0004] At the same time, gain is an important indicator for measuring the radiation performance of an antenna. In the fields of microwave wireless energy transmission and wireless communications, the antenna is required to have good receiving capabilities in a certain direction, which requires the antenna to have high gain characteristics. Summary of the Invention

[0005] In response to the specific antenna requirements of communication systems and microwave wireless energy transmission, this invention proposes a high-gain, broadband antenna based on a resonant ring and cavity-backed structure. This antenna achieves broadband characteristics through the use of a stacked and fractal structure, and achieves high gain through the use of a curved reflector and loaded resonant ring.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A high-gain broadband antenna based on a resonant ring and back cavity structure consists of a stacked and fractal microstrip antenna, a curved reflector, and a resonant ring. The stacked and fractal microstrip antenna is composed of two layers, with the upper microstrip antenna being circular. The radiating patch utilizes a fourth-order iterative circular fractal structure. The lower dielectric layer is clad with copper as a base plate, and the space between the two dielectric layers is filled with air.

[0008] Furthermore, a bowl-shaped back cavity structure is manufactured using 3D printing technology and high-density polyethylene material, and conductive silver glue is sprayed on the inner curved surface to form a curved reflective surface.

[0009] Furthermore, the SMA connector passes through the bowl-shaped back cavity structure, and then its inner conductor and outer conductor pass through the lower dielectric layer. The inner conductor passes through the upper dielectric layer and is connected to the upper radiation patch. The flange is connected to the copper clad at the bottom of the lower dielectric layer.

[0010] Furthermore, the resonant rings are four circular double-ring inverted split resonant rings arranged in a regular pattern. These resonant rings are printed on a dielectric substrate and then mounted on top of a bowl-shaped back cavity structure.

[0011] The beneficial effects of the above solution adopted by the present invention are:

[0012] The present invention effectively increases the working bandwidth of the antenna by adopting a stacked and fractal structure, and at the same time effectively improves the gain of the antenna in the end-fire direction by adopting a loaded resonant ring and a curved reflective surface; and has the advantages of simple structure, low cost, wide bandwidth, high gain, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a front view of an embodiment of the present invention.

[0014] Figure 2 4 is a structural diagram of a microstrip antenna in an embodiment of the present invention.

[0015] FIG3 is a structural diagram of a resonant ring in an embodiment of the present invention.

[0016] Figure 4 is the antenna reflection coefficient in the embodiment of the present invention.

[0017] FIG5 is a radiation pattern of the antenna in an embodiment of the present invention at frequencies of 5.7 GHz, 6.0 GHz, 6.3 GHz, and 6.6 GHz, respectively.

[0018] In the figure: 1. Resonant ring, 2. Microstrip antenna with stacked and fractal structure, 3. SMA connector, 4. Curved reflective surface made of sprayed conductive silver glue, 5. Bowl-shaped back cavity structure, 6. Inner curved surface of bowl-shaped back cavity structure, 7. Feeding point. DETAILED DESCRIPTION

[0019] The present invention will be further described with reference to the accompanying drawings and specific embodiments.

[0020] In order to clearly illustrate the technical solutions in the embodiments of the present invention, the following is a description of the embodiments of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0021] A high-gain broadband antenna based on a resonant ring and back cavity structure comprises a curved reflector, a stacked and fractal microstrip antenna, and a resonant ring. The stacked and fractal microstrip antenna is mounted inside a bowl-shaped back cavity structure, on top of which four resonant rings with a double-ring inverted split structure are mounted.

[0022] In order to ensure the accuracy and convenience of the solution implementation, the center of the bottom of the bowl-shaped back cavity structure is taken as the origin of the rectangular coordinate system, the offset direction along the microstrip antenna feeding point is taken as the positive direction of the X-axis, the bottom of the back cavity structure and the direction perpendicular to the X-axis are selected as the Y-axis, and the central axis of the bowl-shaped back cavity structure is taken as the Z-axis, and the upward direction is the positive direction.

[0023] Table 1 Back cavity structural parameters

[0024]

[0025] Furthermore, the curved reflective surface is formed by spraying conductive silver paste on the inner surface of the bowl-shaped back cavity structure, and the back cavity structure is made of high-density polyethylene material. The parameters of the bowl-shaped back cavity structure are finally determined as shown in Table 1.

[0026] Furthermore, the stacked and fractal structure microstrip antenna has a total of two layers, and the dielectric constant of the substrate used in the two layers is 2.25, the thickness is 1.6mm, and the radius is 37.8mm. The radiating patch is printed on the top of the upper substrate, and a 4th-order iterative circular fractal structure is used to groove the copper clad on the top of the upper substrate. Two symmetrical fan-shaped grooves with a width of 3.51mm and an angle of 145° are opened at a distance of 10.9mm from the center of the circle along the X-axis, forming a first-order fractal structure. Two symmetrical fan-shaped grooves with a width of 3.51mm and an angle of 145° are opened at a distance of 3.31mm from the first groove along the Y-axis, forming a second-order fractal structure. Similarly, third-order and fourth-order fractal structures are constructed. The copper base of the lower substrate is used as the bottom plate of the stacked and fractal structure microstrip antenna, and it is installed below the upper substrate at a distance of 2.05mm. The feeding point is 6.6mm along the X-axis. The structural parameters of the finally determined stacked structure and fractal structure microstrip antenna are shown in Table 2.

[0027] Table 2 Structural parameters of stacked and fractal microstrip antennas

[0028]

[0029] Furthermore, after the SMA connector passes through the bowl-shaped back cavity structure, the flange is connected to the bottom plate of the fractal and stacked structure microstrip antenna. Then, after the inner conductor and the outer conductor pass through the lower dielectric substrate, the inner conductor passes through the upper dielectric substrate and is connected to the radiation patch.

[0030] Furthermore, the resonant rings were printed on a circular dielectric substrate with a thickness of 1.6 mm and a radius of 73.6 mm. The substrate had a dielectric constant of 2.55. The resonant rings had a dual-ring inverted split structure: the inner ring had a radius of 3.69 mm, a width of 1.76 mm, and a split angle of 9°; the outer ring had a radius of 10.31 mm, a width of 1.76 mm, and a split angle of 5°. The coordinates of the centers of the four resonant rings (A, B, C, and D) on the dielectric substrate were A (15.74 mm, 13.69 mm), B (15.74 mm, -13.69 mm), C (-15.74 mm, 13.69 mm), and D (-15.74 mm, -13.69 mm). The outer ring openings of resonant rings A and B faced the positive X-axis, while those of resonant rings C and D faced the negative X-axis. The final structural parameters of the resonant rings are shown in Table 3.

[0031] Table 3 Resonant ring structure parameters

[0032]

[0033] The bowl-shaped back cavity structure, the curved reflecting surface, the stacked and fractal microstrip antenna, and the resonant ring are concentric.

[0034] Further, Figure 4 The reflection coefficient of the antenna is given. It can be seen from the figure that the operating frequency of the antenna is 5.61GHz~6.72GHz, and the relative bandwidth is 18%.

[0035] Furthermore, FIG5 shows the radiation pattern of the antenna at frequencies of 5.7 GHz, 6.0 GHz, 6.3 GHz, and 6.6 GHz. It can be seen from the figure that the gain of the antenna within the operating frequency range is 10.9 dBi to 14.6 dBi, and the gain is highest at a frequency of 5.7 GHz.

[0036] Brief working principle of the present invention:

[0037] In order to achieve high gain and wide-band performance of the antenna, a microstrip antenna with a stacked and fractal structure was used to effectively improve the antenna's operating bandwidth. The antenna's gain was then improved by installing it in a bowl-shaped back cavity structure. After loading it with a double-ring reverse-open resonant ring, the antenna's operating bandwidth and gain were further improved.

Claims

1. A high-gain broadband antenna based on a resonant ring and back cavity structure, characterized by: The main body of the antenna comprises a microstrip antenna (2) with a stacked and fractal structure, a curved reflective surface (4), a resonant ring (1), and a bowl-shaped back cavity structure (5); the curved reflective surface (4) is a part of the inner curved surface (6) of the bowl-shaped back cavity structure and is sprayed with conductive silver glue; the microstrip antenna (2) with a stacked and fractal structure is located inside the bowl-shaped back cavity structure (5); the resonant ring (1) is located on the top of the bowl-shaped back cavity structure (5); The stacked and fractal structured microstrip antenna (2) is composed of two layers. The stacked and fractal structured microstrip antenna has two layers in total, with a certain distance between the two layers. The microstrip antenna is circular, and a radiation patch is placed on an upper substrate. The radiation patch is grooved on the copper clad on the top of the upper substrate using a 4th-order iterative circular ring fractal structure. Two symmetrical annular grooves with an angle of 145° are opened at a certain distance from the center of the circle along the X axis, forming a 1st-order fractal structure. Two symmetrical annular grooves with an angle of 145° are opened at a certain distance from the first groove along the Y axis, forming a 2nd-order fractal structure. Similarly, 3rd-order and 4th-order fractal structures are constructed. The copper clad bottom plate of the lower substrate serves as the bottom plate of the stacked and fractal structured microstrip antenna. The resonant ring (1) is a double-ring reverse-open inner and outer ring structure; the bowl-shaped back cavity structure (5), the curved reflective surface (4), the stacked and fractal microstrip antenna (2), and the resonant ring (1) are concentric.

2. The high-gain broadband antenna based on a resonant ring and back cavity structure according to claim 1, characterized in that: The bowl-shaped back cavity structure (5) is made of high-density polyethylene material using 3D printing technology. Its external shape is a cylinder with a radius of 73.6 mm and a height of 28.7 mm. The internal curved surface (6) of the bowl-shaped back cavity structure is a sphere with a radius of 134.7 mm and an angle of 63.6°. The extended part of the bowl-shaped back cavity structure (5) is 22.2 mm in height and has a wall thickness of 3 mm.

3. The high-gain broadband antenna based on a resonant ring and back cavity structure according to claim 1, characterized in that: The curved reflective surface (4) is a part of the inner curved surface (6) of the bowl-shaped back cavity structure, and is in the form of a sphere with a radius of 134.7 mm and an angle of 59.6°, on which conductive silver glue is sprayed.

4. The high-gain broadband antenna based on a resonant ring and back cavity structure according to claim 1, characterized in that: The radii of the upper and lower layers of the microstrip antenna (2) are both 37.8 mm, the distance between the two layers is 2.05 mm, and the distance between the lower layer and the bottom of the bowl-shaped back cavity structure is 17.85 mm.

5. The high-gain broadband antenna based on a resonant ring and back cavity structure according to claim 1, characterized in that: The dielectric constant of the upper dielectric substrate of the stacked and fractal structured microstrip antenna (2) is 2.55, the thickness is 1.6 mm, the groove width of the fourth-order iterative circular fractal structure is 3.51 mm, the distance between the grooves is 3.31 mm, the angle of the circular groove is 145°, and the distance between the first-order fractal structure and the center of the circle is 10.9 mm.

6. The high-gain broadband antenna based on a resonant ring and back cavity structure according to claim 1, characterized in that: The dielectric constant of the lower dielectric substrate of the stacked and fractal structured microstrip antenna (2) is 2.55, and the thickness is 1.6 mm.

7. The high-gain broadband antenna based on a resonant ring and back cavity structure according to claim 1, characterized in that: The resonant ring (1) is printed on a dielectric substrate with a dielectric constant of 2.55, a radius of 73.6 mm, and a thickness of 1.6 mm; the inner ring of the resonant ring (1) has a radius of 3.09 mm, a ring width of 1.76 mm, and an opening angle of 9°; the outer ring has a radius of 9.51 mm, a ring width of 1.76 mm, and an opening angle of 5°.

8. The high-gain broadband antenna based on a resonant ring and back cavity structure according to claim 1, characterized in that: There are four dual-ring inverted split-structure resonant rings, which are distributed at the four vertices of a rectangle with the center of the dielectric substrate as the midpoint and side lengths of 31.48 mm and 27.38 mm respectively. The openings of the outer rings of the four inverted split-structure resonant rings are perpendicular to the long sides of the rectangle and face the edge of the dielectric substrate.

9. The high-gain broadband antenna based on a resonant ring and back cavity structure according to claim 1, characterized in that: The antenna operates in the frequency band of 5.61 GHz to 6.72 GHz.

10. The high-gain broadband antenna based on a resonant ring and back cavity structure according to claim 1, characterized in that: The antenna gain in the operating frequency band is 10.9dBi to 14.6dBi, and the gain is maximum at a frequency of 5.7GHz.

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