High-gain directional broadband antenna

Abstract

The invention discloses a high-gain directional broadband antenna, which comprises a metal grounding plate, a radiation layer, a feed patch and an air dielectric layer, the radiation layer comprises a first radiation metal patch and a second radiation metal patch which are of an asymmetric structure; the feed patch is located between the first radiation metal patch and the second radiation metal patch. According to the antenna, the first radiation metal patch and the second radiation metal patch which are asymmetric are adopted, so that the resonant frequencies of the two patch antennas have a certain difference, the metal radiation antenna is connected with the metal grounding plate through a certain number of metal short-circuit columns, the radiation performance of the radiation antenna close to the middle feed patch is enhanced, and the radiation performance of the antenna is improved. The difference between the resonant frequencies of the two antennas is controlled by changing the position of the middle feed patch, and meanwhile, the effect of introducing a capacitor to improve the impedance characteristic of the antenna is achieved by introducing a gap between the feed patch and the radiation metal patch, so that the total bandwidth of the antenna is widened.

Description

Technical Field

[0001] The invention belongs to the technical field of unmanned aerial vehicle antennas, and specifically relates to a high-gain directional broadband antenna. Background Art

[0002] Nowadays, broadband antennas are one of the key technologies in the field of wireless communications and are widely used in the fields of communications, radar, satellite navigation, etc. The world's science and technology is developing rapidly. With the continuous development of communication technology, the performance requirements for broadband antennas are getting higher and higher, especially in broadband characteristics such as antenna gain, antenna radiation pattern and antenna standing wave ratio. Generally speaking, the bandwidth of patch antennas is about 3%, so the research of ultra-wideband patch antennas is crucial to the development of the field of wireless communications.

[0003] Given the inherent high-Q properties of microstrip patch antennas, broadening their bandwidth becomes a key challenge. To directly address this challenge, common strategies include increasing the thickness of the antenna dielectric substrate or selecting a dielectric material with a lower dielectric constant. These measures are intended to optimize the electromagnetic performance of the antenna and thus expand its operating bandwidth.

[0004] At present, common ways to achieve broadband include: loading parasitic units, using multi-layer patches, etc. However, the method of loading parasitic units will expand the lateral cross-section of the antenna, and the method of using multi-layer patches will expand the longitudinal cross-section of the antenna, which will occupy a larger part of the space and increase the weight of the antenna, thereby increasing the weight of the drone. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art and to provide a high-gain directional broadband antenna to meet the requirements of wide bandwidth and high gain of antennas in the field of wireless communications, thereby solving the problems of narrow bandwidth and large size of traditional patch antennas.

[0006] In order to achieve the above purpose, the present invention provides the following scheme: A high-gain directional broadband antenna comprises a metal ground plate, a radiation layer, a feed patch, and an air dielectric layer between the metal ground plate and the radiation layer; The radiation layer includes a first radiation metal patch and a second radiation metal patch of an asymmetric structure; The feed patch adopts a coaxial line feed section, which is located between the first radiation metal patch and the second radiation metal patch; there are gaps between the two ends of the feed patch and the first radiation metal patch and the second radiation metal patch respectively; a feed metal column is provided on the feed patch for connecting the feed patch and the metal ground plate; A group of metal short-circuit column arrays are respectively arranged between the first radiation metal patch, the second radiation metal patch and the metal grounding plate. The metal short-circuit column arrays are composed of a plurality of metal short-circuit columns arranged at equal intervals.

[0007] Furthermore, the first radiating metal patch is a first notch formed on a rectangular metal, and a first microstrip transmission line is arranged in the first notch; the first notch is an integrally formed structure, which includes a rectangular notch and an isosceles trapezoidal notch; the long side of the rectangular notch coincides with the upper base of the isosceles trapezoidal notch, and the lower base of the isosceles trapezoidal notch faces the second radiating metal patch; The first microstrip transmission line is a stepped metal strip on both sides; Furthermore, the second radiating metal patch is a rectangular metal with a second notch, and a second microstrip transmission line is arranged in the second notch; the second notch is an integrally formed structure, which includes a rectangular notch and an isosceles trapezoidal notch, the long side of the rectangular notch coincides with the upper base of the isosceles trapezoidal notch, and the lower base of the isosceles trapezoidal notch faces the first radiating metal patch; The second microstrip transmission line is a metal strip; Further, the center of the first microstrip transmission line, the center of the second microstrip transmission line, and the center of the feeding patch are located on the same straight line; Furthermore, the first radiation metal patch and the second radiation metal patch are respectively provided with different numbers of metal short-circuit pillars in the metal short-circuit pillar array; Furthermore, the air dielectric constant of the air dielectric layer is 1. A low dielectric constant can reduce the Q value of the antenna, thereby increasing the bandwidth of the antenna.

[0008] Furthermore, by adjusting the size of the gap formed by the feed patch and the first radiating metal patch and the second radiating metal patch respectively, the size of the capacitance formed by the feed patch and the first radiating metal patch and the second radiating metal patch respectively is changed, and by adjusting the position of the feed metal column on the feed patch to change the reactance introduced at the feeding point, the impedance matching of the antenna is changed, thereby improving the gain of the antenna and increasing the total bandwidth of the antenna.

[0009] Furthermore, the size of the metal ground plate is larger than the size of the radiation layer.

[0010] Furthermore, by adjusting the difference in shape and size of the two asymmetric first radiating metal patches and the second radiating metal patches, different resonant frequencies of the two patch antennas can be achieved.

[0011] Furthermore, the size of the first radiating metal patch is 0.8-0.9 times that of the second radiating metal patch, forming two close resonance points, thereby increasing the impedance bandwidth of the antenna.

[0012] The present invention adopts two asymmetric first radiating metal patches and second radiating metal patches to make the resonant frequencies of the two patch antennas have a certain difference, and then connects the metal radiating antenna to the metal ground plate through a certain number of metal short-circuit columns, so that the radiation of the radiating antenna close to the middle feed patch is enhanced, and at the same time, the difference in the resonant frequencies of the two antennas is controlled by changing the position of the middle feed patch to achieve the widening of the total bandwidth of the antenna of the present invention. The dielectric substrate of the present invention is air, and the dielectric constant of air is 1. The low dielectric constant can reduce the Q value of the antenna, thereby increasing the bandwidth of the antenna. At the same time, it can replace the method of multi-layer patches and increasing parasitic units to increase the bandwidth to a certain extent, making the cross-section of the antenna smaller and making the weight of the antenna lighter.

[0013] The antenna of the present invention has the following excellent effects: (1) While maintaining the original patch antenna's single-layer patch and single-layer dielectric structure with small size, the antenna's feed point radiation coefficient S11 is approximately 1.31-1.81 GHz in the frequency band below -10 dB, with an absolute bandwidth of 500 MHz and a relative bandwidth of up to 32.1%. Compared with the 3% relative bandwidth of the traditional patch antenna, the antenna of the present invention achieves a breakthrough in broadband.

[0014] (2) The dielectric layer is made of air, and the antenna bandwidth is increased by reducing the Q value of the dielectric plate and digging a gap at the feeding point to introduce a coplanar capacitor to improve impedance matching, thereby replacing the method of multi-layer patches and adding parasitic units. The antenna of the present invention has the characteristics of light weight, miniaturization, cost saving, easy integration, and reducing the weight of the drone. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is a schematic diagram of the structure of a high-gain directional broadband antenna provided by an embodiment of the present invention.

[0017] Figure 2 It is a schematic diagram of the radiation layer and feed patch structure of the antenna provided by an embodiment of the present invention.

[0018] Figure 3 It is an S11 parameter diagram of the antenna provided by an embodiment of the present invention.

[0019] Figure 4 This is the 3D radiation pattern of the antenna provided by the embodiment of the present invention.

[0020] Markings in the figure: 1, metal ground plate; 2, radiation layer; 2-1, first radiation metal patch; 2-1-1, first gap; 2-1-2, first microstrip transmission line; 2-2, second radiation metal patch; 2-2-1, second gap; 2-2-2, second microstrip transmission line; 3, feeding patch; 4, feeding metal column; 5, metal short-circuit column. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0022] In the description of the embodiments of the present invention, it should be noted that the terms "center", "upper", "lower", "inner", "outer" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and 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 devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation. It should not be understood as a limitation on the embodiments of the present invention. In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance. In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense. 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 directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0023] This embodiment provides a high-gain directional broadband antenna, such as Figure 1-2 It includes a metal grounding plate 1, a radiation layer 2, a feeding patch, and an air dielectric layer located between the metal grounding plate 1 and the radiation layer 2; The size of the metal grounding plate 1 is larger than that of the radiation layer 2 and is located below the radiation layer 2. The radiation layer 2 includes a first radiation metal patch 2-1 and a second radiation metal patch 2-2 of an asymmetric structure; the first radiation metal patch 2-1 is a rectangular metal with a first notch 2-1-1, and a first microstrip transmission line is arranged in the first notch 2-1-1; the first notch 2-1-1 is an integrally formed structure, which includes a rectangular notch and an isosceles trapezoidal notch; the long side of the rectangular notch coincides with the upper base of the isosceles trapezoidal notch, and the lower base of the isosceles trapezoidal notch faces the second radiation metal patch 2-2; the first microstrip transmission line The two sides are stepped metal strips; impedance matching is performed by the stepped metal strips on both sides to increase the antenna bandwidth; the second radiating metal patch 2-2 is a second notch 2-2-1 opened on the rectangular metal, and a second microstrip transmission line is arranged in the second notch 2-2-1; the second notch 2-2-1 is an integrated structure, which includes a rectangular notch and an isosceles trapezoidal notch, the long side of the rectangular notch coincides with the upper bottom side of the isosceles trapezoidal notch, and the lower bottom side of the isosceles trapezoidal notch faces the first radiating metal patch 2-1; the second microstrip transmission line is a metal strip;

[0024] The feeding patch adopts a coaxial feeding section, which is located between the first radiating metal patch 2-1 and the second radiating metal patch 2-2; the center of the first microstrip transmission line, the center of the second microstrip transmission line, and the center of the feeding patch are located on the same straight line; there are gaps between the two ends of the feeding patch and the first radiating metal patch 2-1 and the second radiating metal patch 2-2 respectively; a feeding metal column 4 is provided on the feeding patch for connecting the feeding patch with the metal ground plate 1; the distance between the feeding metal column 4 and the center of the feeding patch is 5.1-5.2mm, and the asymmetric distribution of the feeding metal column 4 on the feeding patch can introduce reactances of different values, and improve the impedance characteristics of the antenna together with the different first radiating metal patch 2-1 and the second radiating metal patch 2-2 on both sides.

[0025] A group of metal short-circuit pillars 5 arrays are respectively provided between the first radiating metal patch 2-1, the second radiating metal patch 2-2 and the metal grounding plate 1. The metal short-circuit pillar 5 array is composed of a plurality of metal short-circuit pillars 5 arranged at equal intervals, the radius r of each metal short-circuit pillar 5 is 0.3-0.5mm, the height h is 19-21mm, and the distance between each metal short-circuit pillar 5 is 0.5h. The distance between the metal short-circuit pillar 5 on the first radiating metal patch 2-1 and the outer edge of the first radiating metal patch 2-1 is 16-17mm; the distance between the metal short-circuit pillar 5 on the second radiating metal patch 2-2 and the outer edge of the second radiating metal patch 2-2 is 20-21mm. The number of metal short-circuit pillars 5 in the metal short-circuit pillar 5 arrays provided on the first radiating metal patch 2-1 and the second radiating metal patch 2-2 is different; in this embodiment, the number of metal short-circuit pillars 5 on the first radiating metal patch 2-1 and the second radiating metal patch 2-2 is in a relationship of 11:9. By adding the metal short-circuit column 5, the effective current path can be increased and the size of the antenna can be effectively reduced.

[0026] The air dielectric constant of the air dielectric layer is 1. A low dielectric constant can reduce the Q value of the antenna, thereby increasing the bandwidth of the antenna.

[0027] By adjusting the gap size formed by the feed patch and the first radiation metal patch 2-1 and the second radiation metal patch 2-2, the capacitance size formed by the feed patch and the first radiation metal patch 2-1 and the second radiation metal patch 2-2 is changed, and the position of the feed metal column 4 on the feed patch is adjusted to change the reactance introduced at the feed point, thereby changing the impedance matching of the antenna, thereby improving the gain of the antenna and increasing the total bandwidth of the antenna. The gap between the feed patch and the first radiation metal patch 2-1 is a rectangular gap with a length S1 of 7.1-7.3mm and a width W1 of 1.8-2mm, and the gap between the feed patch and the second radiation metal patch 2-2 is a rectangular gap with a length S2 of 7.1-7.3mm and a width W2 of 2.5-2.6mm. The slot can be equivalent to a capacitor. By loading the slot to achieve the effect of loading the capacitor, the reactance introduced by the feed patch can be compensated, the impedance matching of the antenna can be optimized, and the impedance bandwidth of the antenna can be widened, so that the antenna can work between 1.3GHz and 1.8GHz, with a relative bandwidth of up to 32.25%. Through this layout and shape, the effective electrical length of the current can be effectively increased, the impedance bandwidth of the antenna can be improved, and the size of the antenna can be reduced. At the same time, this layout can make the current distribution on the antenna concentrated on the upper patch, forming a directional radiation pattern, and has the characteristics of high gain at a specific frequency.

[0028] By adjusting the shapes and sizes of the two asymmetric first radiation metal patches 2 - 1 and the second radiation metal patches 2 - 2 , different resonant frequencies of the two patch antennas can be achieved.

[0029] The first radiating metal patch 2-1 is slightly smaller than the second radiating metal patch 2-2. The resonant frequency of the antenna is related to the effective current length of the antenna. Therefore, radiating patches of different sizes can have multiple resonance points. The size of the first radiating metal patch 2-1 is 0.8-0.9 times that of the second radiating metal patch 2-2, forming two close resonance points, thereby increasing the impedance bandwidth of the antenna.

[0030] Table 1 Key dimension parameter values ​​of the antenna in this embodiment Size parameters L1 L2 L3 L4 L5 L6 L7 Value range (mm) 15-16 14-15 24-25 12-13 17-18 14-15 14-15 Size parameters L8 r h D1 D2 D3 S1 Value range (mm) 19-21 0.3-0.5 19-21 16-17 20-21 5.1-5.2 7.1-7.3 Size parameters W1 S2 W3 - - - - Value range (mm) 1.8-2 7.1-7.3 2.5-2.6 - - - - Figure 3 : is an S11 parameter diagram of the antenna provided in an embodiment of the present invention, from which it can be seen that the working frequency band of the antenna is between 1.3 GHz and 1.8 GHz.

[0031] Figure 4 This is the 3D radiation pattern of the antenna provided in the embodiment of the present invention, from which it can be seen that the antenna is a directional antenna and the maximum gain is 6.83dBi.

[0032] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A high-gain directional broadband antenna, characterized in that It includes a metal ground plate (1), a radiation layer (2), a feed patch (3), and an air dielectric layer located between the metal ground plate (1) and the radiation layer (2); The radiation layer (2) comprises a first radiation metal patch (2-1) and a second radiation metal patch (2-2) of an asymmetric structure; The feed patch (3) adopts a coaxial feed section, which is located between the first radiating metal patch (2-1) and the second radiating metal patch (2-2); gaps exist between the two ends of the feed patch (3) and the first radiating metal patch (2-1) and the second radiating metal patch (2-2); a feed metal column (4) is provided on the feed patch (3) for connecting the feed patch (3) and the metal ground plate (1); A group of metal short-circuit column (5) arrays are respectively provided between the first radiation metal patch (2-1), the second radiation metal patch (2-2) and the metal grounding plate (1).

2. A high-gain directional broadband antenna according to claim 1, characterized in that: The first radiation metal patch (2-1) is a rectangular metal with a first notch (2-1-1), and a first microstrip transmission line (2-1-2) is arranged in the first notch (2-1-1); The second radiation metal patch (2-2) is a rectangular metal with a second notch (2-2-1), and a second microstrip transmission line (2-2-2) is arranged in the second notch (2-2-1).

3. A high-gain directional broadband antenna according to claim 2, characterized in that: The first notch (2-1-1) is an integrally formed structure, which includes a rectangular notch and an isosceles trapezoidal notch; the long side of the rectangular notch coincides with the upper base of the isosceles trapezoidal notch, and the lower base of the isosceles trapezoidal notch faces the second radiating metal patch (2-2); the second notch (2-2-1) is an integrally formed structure, which includes a rectangular notch and an isosceles trapezoidal notch, the long side of the rectangular notch coincides with the upper base of the isosceles trapezoidal notch, and the lower base of the isosceles trapezoidal notch faces the first radiating metal patch (2-1).

4. The high-gain directional broadband antenna according to claim 2, characterized in that: The first microstrip transmission line (2-1-2) is a stepped metal strip on both sides; the second microstrip transmission line (2-2-2) is a metal strip.

5. The high-gain directional broadband antenna according to claim 2, characterized in that: The center of the first microstrip transmission line (2-1-2), the center of the second microstrip transmission line (2-2-2), and the center of the feed patch (3) are located on the same straight line.

6. The high-gain directional broadband antenna according to claim 1, characterized in that: The metal short-circuit column (5) array is composed of a plurality of metal short-circuit columns (5) arranged at equal intervals.

7. The high-gain directional broadband antenna according to claim 6, characterized in that: The first radiation metal patch (2-1) and the second radiation metal patch (2-2) are respectively provided with metal short-circuit column (5) arrays having different numbers of metal short-circuit columns (5).

8. The high-gain directional broadband antenna according to claim 1, characterized in that: By adjusting the size of the gap formed by the feed patch (3) and the first radiating metal patch (2-1) and the second radiating metal patch (2-2), the size of the capacitance formed by the feed patch (3) and the first radiating metal patch (2-1) and the second radiating metal patch (2-2) is changed, and by adjusting the position of the feed metal column (4) on the feed patch (3), the reactance introduced at the feed point is changed, thereby changing the impedance matching of the antenna, thereby improving the gain of the antenna and increasing the total bandwidth of the antenna.

9. The high-gain directional broadband antenna according to claim 1, characterized in that: By adjusting the shape and size differences of two asymmetric first radiation metal patches (2-1) and second radiation metal patches (2-2), different resonant frequencies of the two patch antennas are achieved.

10. The high-gain directional broadband antenna according to claim 1, characterized in that: The size of the first radiation metal patch (2-1) is 0.8-0.9 times that of the second radiation metal patch (2-2), forming two close resonance points, thereby increasing the impedance bandwidth of the antenna.

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