L-band omnidirectional wideband antenna for unmanned aerial vehicle

Abstract

The application discloses an L-band unmanned aerial vehicle omnidirectional broadband antenna, which comprises an upper layer metal radiation patch, a lower layer metal grounding plate, air medium and a coaxial line feed; the upper layer metal radiation patch comprises a central metal patch and a plurality of antenna branches which are periodically distributed in the circumference of the central metal patch; the branches of the upper layer metal radiation patch are in a central symmetry of a special structure, the uniform distribution of current sources is realized in the working frequency band, thus the omnidirectional radiation characteristic of the antenna is realized; meanwhile, the addition of the third antenna sub-branch and the circular design of the front end of the main branch make the effective length of the current on the antenna patch larger, so that the antenna can work in a lower frequency band; by adjusting the relative position and angle of the second antenna sub-branch and the first antenna sub-branch, the impedance matching of the antenna can be optimized without affecting the gain of the antenna, so that the antenna realizes a wider frequency band, the antenna gain is improved, and the performance of the antenna is improved.

Description

Technical Field

[0001] The present invention belongs to the field of antenna technology, and in particular relates to an L-band unmanned aerial vehicle omnidirectional broadband antenna. Background Art

[0002] Modern communications technology is undergoing a significant transformation towards miniaturization and integration, a trend vividly reflected in various communications devices. For example, mobile phone antenna designs have evolved from the bulky monopole antennas of the early days to the compact, built-in patch antennas of today, significantly improving user convenience. Similar miniaturization innovations are also permeating base station antennas, vehicle-mounted antennas, and backpack radio antennas, all of which are adopting more compact designs to suit the needs of diverse application scenarios.

[0003] Antenna miniaturization not only reduces the overall weight of communication systems, making them more portable, but also opens the door to optimized internal structures, freeing up space for integrating more components and complex circuits. This change not only enhances device portability but also promotes the diversification of communication system functions and further improvements in performance, laying a solid foundation for the rapid development of modern communication technology.

[0004] Conventional patch antennas have very low bandwidth and are not suitable for specific environments. Therefore, designing a high-gain, high-bandwidth, omnidirectional antenna is extremely important. Furthermore, conventional antennas use different dielectric substrate materials, which increases the cost of the antenna. Using an air dielectric layer can reduce production costs, reduce antenna weight, and reduce the power consumption 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 provide an L-band omnidirectional broadband antenna for UAVs.

[0006] The present invention is implemented as follows: an L-band UAV omnidirectional broadband antenna includes an upper metal radiation patch, a lower metal ground plate, an air dielectric, and a coaxial line feed; wherein the air dielectric is left between the upper metal radiation patch and the lower metal ground plate;

[0007] The upper metal radiation patch includes a central metal patch and a plurality of antenna branches periodically distributed around the central metal patch;

[0008] The plurality of antenna branches are arranged in a centrosymmetric manner about the center of the central metal patch;

[0009] Each antenna branch includes a main branch, two first antenna sub-branches, two second antenna sub-branches, and two third antenna sub-branches;

[0010] The two first antenna sub-branches are arranged symmetrically about the main branch axis; the two second antenna sub-branches are arranged symmetrically about the main branch axis; the two third antenna sub-branches are arranged symmetrically about the main branch axis; and the third antenna sub-branches are in contact with the front ends of the third antenna sub-branches of the adjacent antenna branches;

[0011] The structure of the lower metal ground plate is the same as that of the upper metal radiation patch, but its size is larger than that of the upper metal radiation patch;

[0012] One end of the coaxial line feed contacts the central metal patch of the upper metal radiation patch, and the other end forms an annular gap with the central metal patch of the lower metal ground plate;

[0013] Preferably, the front ends of the main branch, the first antenna sub-branch, and the second antenna sub-branch are all circular structures;

[0014] Preferably, the size of the lower metal ground plate is 1.5-1.6 times that of the upper metal radiation patch;

[0015] Preferably, the ratio of the distance between the first antenna sub-branch and the second antenna sub-branch to the distance between the second antenna sub-branch and the third antenna sub-branch on the same side of the same antenna branch is 0.24-0.27;

[0016] Preferably, the third antenna sub-branch is located at the connection position between the main branch and the central metal patch;

[0017] Preferably, the first antenna branch and the second antenna branch have the same length;

[0018] Preferably, the first antenna sub-branch, the second antenna sub-branch, the third antenna sub-branch and the main branch have the same included angle.

[0019] The beneficial effects of the present invention are:

[0020] The present invention uses a special structure of centrosymmetry in the branches of the upper metal radiation patch to achieve uniform distribution of the current source within the operating frequency band, thereby realizing the omnidirectional radiation characteristics of the antenna. At the same time, the addition of the third antenna sub-branch and the circular design of the front end of the main branch increase the effective length of the current on the antenna patch, enabling the antenna to operate in a lower frequency band.

[0021] By adjusting the relative position and angle of the second antenna sub-branch and the first antenna sub-branch, this invention optimizes the antenna's impedance matching without affecting the antenna's gain, enabling the antenna to achieve a wider frequency bandwidth, increasing antenna gain and enhancing antenna performance. Furthermore, the dielectric substrate is air, whose low dielectric constant reduces the antenna's Q factor and increases its bandwidth. Compared to conventional patch antennas that require an additional dielectric layer, this invention saves material, reduces the overall antenna mass, and is more environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments. 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 any creative work.

[0023] Figure 1 Schematic diagram of the structure of an L-band UAV omnidirectional broadband antenna provided by an embodiment of the present invention.

[0024] Figure 2 This is a schematic structural diagram of the upper metal radiation patch in the L-band UAV omnidirectional broadband antenna provided by an embodiment of the present invention.

[0025] Figure 3 This is an S11 parameter diagram of the L-band UAV omnidirectional broadband antenna provided by an embodiment of the present invention.

[0026] Figure 4 This is a 3D gain diagram of the L-band UAV omnidirectional broadband antenna provided by an embodiment of the present invention.

[0027] Markings in the figure: 1, upper metal radiation patch; 1-1, central metal patch; 1-2, antenna branch; 1-2-1, main branch; 1-2-2, first antenna sub-branch; 1-2-3, second antenna sub-branch; 1-2-4, third antenna sub-branch; 2, lower metal ground plate; 3, coaxial line feed; 4, annular gap. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0029] like Figure 1 As shown, an embodiment of the present invention provides an L-band omnidirectional broadband antenna for drones. It measures 43mm*38mm*20mm and operates in the 1.3-1.5GHz frequency band. It features a wide bandwidth, lower return loss, and higher gain within the low-frequency band, with an S11 parameter of -30dB at a center frequency of 1.4GHz. The antenna comprises an upper metal radiating patch, a coaxial feeder cable, a lower metal ground plate, and an air dielectric. The upper metal radiating patch and the lower metal ground plate are connected by a coaxial feeder cable and are stacked.

[0030] like Figure 2 As shown, the upper metal radiation patch includes a central metal patch and a plurality of antenna branches periodically distributed around the central metal patch;

[0031] The plurality of antenna branches are arranged symmetrically about the center of the central metal patch, and adjacent antenna branches form a certain angle;

[0032] Each antenna branch includes a long strip main branch with a circular patch at the front end, two first antenna sub-branches, two second antenna sub-branches, and two third antenna sub-branches; the two first antenna sub-branches are arranged symmetrically about the main branch axis; the two second antenna sub-branches are arranged symmetrically about the main branch axis; and the two third antenna sub-branches are arranged symmetrically about the main branch axis; and the third antenna sub-branch contacts the front end of the third antenna sub-branch of the adjacent antenna branch, forming an eight-shaped shape;

[0033] Located on the same side of the same antenna branch, the ratio of the distance between the first antenna sub-branch and the second antenna sub-branch to the distance between the second antenna branch and the third antenna branch is 0.24-0.27;

[0034] The structure of the lower metal ground plate is the same as that of the upper metal radiation patch, but its size is larger than that of the upper metal radiation patch;

[0035] One end of the coaxial line feed contacts the central metal patch of the upper metal radiation patch, and the other end forms an annular gap with the central metal patch of the lower metal ground plate;

[0036] The radius of the circular patch at the front end of the main branch is 0.9±0.1mm

[0037] The length of the first antenna sub-branch and the second antenna sub-branch is 2.4-2.6 mm, the first antenna sub-branch and the second antenna sub-branch are separated by 1.7-1.9 mm, the second antenna sub-branch is 6.8-7.2 mm from the center of the central metal patch, and the first antenna sub-branch is 8.8-9.2 mm from the center of the central metal patch; the angle between the first antenna sub-branch and the second antenna sub-branch and the main branch is 58°-62°;

[0038] The radius of the central metal patch is 4.0-4.4 mm; the front ends of the first antenna sub-branch and the second antenna sub-branch are circular patches with a radius of 0.33-0.37 mm;

[0039] The coaxial line feed height is 19-21 mm;

[0040] The lower metal patch structure is the same as the overall structure of the upper metal radiating patch, and the size is 1.5-1.6 times that of the upper metal radiating patch.

[0041] Figure 3 This is an S11 parameter diagram of the L-band UAV omnidirectional broadband antenna provided by an embodiment of the present invention. As can be seen from the figure, the operating frequency band of the antenna is between 1.3 GHz and 1.5 GHz.

[0042] Figure 4 This is a 3D gain diagram of the L-band UAV omnidirectional broadband antenna provided by an embodiment of the present invention. As can be seen from the figure, the antenna has relatively good radiation characteristics and the gain can reach 0.74dB.

[0043] The above is 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 principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. An L-band UAV omnidirectional broadband antenna, characterized in that It comprises an upper metal radiation patch (1), a lower metal ground plate (2), an air medium, and a coaxial line feed (3); wherein the air medium is left between the upper metal radiation patch (1) and the lower metal ground plate (2); The upper metal radiation patch (1) comprises a central metal patch (1-1) and a plurality of antenna branches (1-2) periodically distributed around the central metal patch (1-1); The plurality of antenna branches (1-2) are arranged in a centrosymmetric manner about the center of the central metal patch (1-1); Each antenna branch (1-2) includes a main branch (1-2-1), two first antenna sub-branches (1-2-2), two second antenna sub-branches (1-2-3), and two third antenna sub-branches (1-2-4); The two first antenna sub-branches (1-2-2) are arranged symmetrically about the main branch (1-2-1); the two second antenna sub-branches (1-2-3) are arranged symmetrically about the main branch (1-2-1); the two third antenna sub-branches (1-2-4) are arranged symmetrically about the main branch (1-2-1); and the third antenna sub-branches (1-2-4) are in contact with the front ends of the third antenna sub-branches (1-2-4) of the adjacent antenna branches (1-2); The structure of the lower metal ground plate (2) is the same as that of the upper metal radiation patch (1), but its size is larger than that of the upper metal radiation patch (1); One end of the coaxial line feed (3) contacts the central metal patch (1-1) of the upper metal radiation patch (1), and the other end forms an annular gap (4) with the central metal patch (1-1) of the lower metal grounding plate (2).

2. The L-band UAV omnidirectional broadband antenna according to claim 1, characterized in that: The front ends of the main branch (1-2-1), the first antenna sub-branch (1-2-2), and the second antenna sub-branch (1-2-3) are all circular structures.

3. The L-band UAV omnidirectional broadband antenna according to claim 1, characterized in that: The size of the lower metal grounding plate (2) is 1.5-1.6 times that of the upper metal radiation patch (1).

4. The L-band UAV omnidirectional broadband antenna according to claim 1, characterized in that: Located on the same side of the same antenna branch (1-2), the ratio of the distance between the first antenna sub-branch (1-2-2) and the second antenna sub-branch (1-2-3) to the distance between the second antenna sub-branch (1-2-3) and the third antenna sub-branch (1-2-4) is 0.24-0.

27.

5. The L-band UAV omnidirectional broadband antenna according to claim 1, characterized in that: The third antenna sub-branch (1-2-4) is located at the connection position between the main branch (1-2-1) and the central metal patch (1-1).

6. The L-band UAV omnidirectional broadband antenna according to claim 1, characterized in that: The first antenna branch (1-2) and the second antenna branch (1-2) have the same length.

7. The L-band UAV omnidirectional broadband antenna according to claim 1, characterized in that: The first antenna sub-branch (1-2-2), the second antenna sub-branch (1-2-3), the third antenna sub-branch (1-2-4) and the main branch (1-2-1) have the same included angle.

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