Ultra-wideband omni-directional drone antenna

Abstract

The application discloses an ultra-wideband omnidirectional unmanned aerial vehicle antenna, and relates to the technical field of antennas, in particular to an ultra-wideband omnidirectional unmanned aerial vehicle antenna with a working frequency band covering 400-560MHz. The antenna comprises a radiation structure, a grounding plate, a feeding structure and an air dielectric layer. The upper layer metal patch comprises four water-drop-shaped patches and a circular patch. The shape of the grounding plate is the same as that of the upper layer metal patch, but the size is slightly larger. The antenna uses the gradually changing radiation patch to realize impedance transformation from the feeding point to the free space, so that the antenna performance changes slowly with the frequency, the antenna bandwidth is improved, the isolation of the antenna is improved due to the fact that the feeding points are distributed at two separate patches, the metal feeding line loaded with a 50Ω resistor is introduced to change the current path and distribution on the patch, the antenna resonance efficiency is reduced, the large bandwidth and high gain requirements are effectively achieved with less material, the two-port feeding mode is set to the same-phase equal-amplitude feeding to prevent the antenna pattern from being distorted, and the omnidirectionality of the antenna is ensured.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of antennas, and particularly relates to an ultra-wideband omnidirectional unmanned aerial vehicle antenna, which has a working frequency band covering 400 MHz-560 MHz. BACKGROUND

[0002] The 400-560 MHz frequency band belongs to a lower frequency band and has good propagation characteristics, can penetrate buildings and obstacles, and is suitable for wireless communication scenes requiring wide coverage and deep penetration. Generally, patch antennas and whip antennas are used to realize coverage of the 400-560 MHz frequency band.

[0003] However, the design of a low-frequency band antenna is often affected by the trade-off between physical size and electrical performance. In order to realize a high bandwidth, the antenna needs to have a relatively wide impedance bandwidth and resonance bandwidth, so the physical size of the low-frequency band antenna is relatively large and is limited by physical parameters such as wavelength, making it particularly difficult to realize a high bandwidth while maintaining the size of the antenna.

[0004] Through retrieval, CN202021080953.0 discloses a 400M whip wideband suction cup antenna, which improves the fixation of the antenna, but in the use process, the heat dissipation effect is poor due to the structure, and the size is too large, which is not easy to conform. CN20150628217.1 discloses a 433MHz miniaturized omnidirectional microstrip antenna, which avoids the defects of high return loss and low antenna radiation efficiency, but still has the problem of low bandwidth, and the working frequency band is only between 430.1919-436 MHz. CNCN201611061947.9 discloses a four-leaf clover-shaped wideband circularly polarized planar antenna, which realizes the characteristics of a large bandwidth, but the directional diagram is not omnidirectional.

[0005] Therefore, at least how to improve the large size, small bandwidth, low gain of the patch antenna and the difficulty of conforming of the whip antenna is a technical problem to be solved by those skilled in the art. SUMMARY

[0006] The purpose of the present application is to solve the problems of the prior art, and provide an ultra-wideband omnidirectional unmanned aerial vehicle antenna, which has the advantages of small size, large bandwidth, high gain and easy conforming.

[0007] To this end, the present application provides an ultra-wideband omnidirectional unmanned aerial vehicle antenna, which has a working frequency band covering 400 MHz-560 MHz, and comprises a radiation structure, a ground plate, a feeding structure and an air dielectric layer.

[0008] The radiation structure comprises an upper layer metal patch.

[0009] The ground plate is located below the radiation structure.

[0010] The air medium layer is distributed between the upper metal patch and the ground plate.

[0011] The feed structure penetrates the air medium layer and includes a plurality of metal feed lines.

[0012] The upper metal patch includes four water-drop-shaped patches and a circular patch.

[0013] The four water-drop-shaped patches are symmetrically distributed about the center, the tips of the four water-drop-shaped patches are connected to the circular patch, and the centers of the four water-drop-shaped patches overlap the center of the circular patch.

[0014] The ground plate has the same shape as the upper metal patch but is larger in size than the upper metal patch.

[0015] The ground plate is 1.2-1.3 times larger in size than the upper metal patch, preferably 1.2221 times larger in size.

[0016] The four water-drop-shaped patches of the upper metal patch correspond one-to-one to the four water-drop-shaped patches of the ground plate, and each water-drop-shaped patch of the upper metal patch and the corresponding water-drop-shaped patch of the ground plate are connected by a metal feed line.

[0017] Two metal shorting posts are respectively arranged between each pair of adjacent water-drop-shaped patches of the upper metal patch and the corresponding water-drop-shaped patches of the ground plate.

[0018] The distance between the upper metal patch and the ground plate is 1 / 15-1 / 16 of the wavelength of the center operating frequency, preferably 1 / 15.6.

[0019] The distance between the upper metal patch and the ground plate is 7-8 times, preferably 8 times, the radius of the circular patch of the upper metal patch.

[0020] The two metal feed lines on the two water-drop-shaped patches without metal shorting posts are in-phase and equal-amplitude feeding.

[0021] The two metal feed lines on the two water-drop-shaped patches with metal shorting posts are not fed, and the metal feed lines are each loaded with a 50Ω resistor to improve current distribution and reduce the resonant frequency of the antenna.

[0022] On the water-drop-shaped patch with metal shorting posts, the metal feed line and the two metal shorting posts are arranged along the central axis of the water-drop-shaped patch from the outside to the inside.

[0023] The distance between the two metal shorting posts on the water-drop-shaped patch is 1 / 124-1 / 125, preferably 1 / 124.8, of the center working frequency, and the distance between the metal feed line on the current water-drop-shaped patch and the nearest metal shorting post is 1 / 1247-1 / 1249, preferably 1 / 1248, of the center working frequency;

[0024] The water-drop-shaped patch of the upper metal patch gradually widens and then gradually narrows from inside to outside, and the end of the patch is in a circular arc shape, the gradual change from inside to outside can make the impedance matching more smooth, and the circular arc at the end can make the antenna pattern not distorted; preferably, the length is 1 / 4 of the wavelength corresponding to the center working frequency, the widest part is 1 / 6-1 / 7, preferably 1 / 6.6, of the wavelength corresponding to the center working frequency, and the angle of the sharp end opening is 50°;

[0025] Further, the patches connected by the two metal feed lines of the feed are orthogonal to each other;

[0026] Further, the patches connected by the two metal feed lines without feed are orthogonal to each other;

[0027] As can be seen from the technical solutions provided by the above application, compared with the prior art, the application provides a 400-560MHz ultra-wideband conformal unmanned aerial vehicle antenna, which can realize impedance transformation from a feed point to free space by using a gradually changing structure of a radiation patch, so that the antenna performance changes slowly with frequency, the bandwidth of the antenna is improved, the tail of the radiation patch is designed in a circular arc shape to reduce the distortion of the pattern, and a metal feed line with a 50Ω resistor is introduced to change the current path and distribution on the patch and reduce the resonance efficiency of the antenna, so that the requirements of large bandwidth and high gain are effectively met with less material, the feed mode of the two ports is set to in-phase and equal-amplitude feed to prevent the antenna pattern from being distorted and ensure the omnidirectionality of the antenna, and the upper and lower ground plates of the antenna are metal sheets, which are easy to conform. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 A top view of a 400MHz-560MHz ultra-wideband omnidirectional unmanned aerial vehicle antenna is provided;

[0029] Figure 2 A perspective view of a 400MHz-560MHz ultra-wideband omnidirectional unmanned aerial vehicle antenna is provided;

[0030] Figure 3 A 400MHz-560MHz ultra-wideband omnidirectional unmanned aerial vehicle antenna simulation S11 parameter diagram is provided;

[0031] Figure 4a is a 400MHz-560MHz ultra-wideband omnidirectional unmanned aerial vehicle antenna provided by the application, and the E-plane (i.e. the electric plane, i.e. the direction plane parallel to the electric field direction) radiation pattern of the antenna obtained by simulation and simulation;

[0032] Figure 4 b is a 400MHz-560MHz ultra-wideband omnidirectional unmanned aerial vehicle antenna provided by the application, and the H-plane (i.e. the magnetic plane, i.e. the direction plane parallel to the magnetic field direction) radiation pattern of the antenna obtained by simulation and simulation;

[0033] Wherein: 1, upper layer metal patch; 1-1, first water drop-shaped patch; 1-2, second water drop-shaped patch; 1-3, third water drop-shaped patch; 1-4, fourth water drop-shaped patch; 1-5, first circular patch; 2, lower layer ground plate; 2-1, fifth water drop-shaped patch; 2-2, sixth water drop-shaped patch; 2-3, seventh water drop-shaped patch; 2-4, eighth water drop-shaped patch; 2-5, second circular patch; 3, first metal feed line; 4, second metal feed line; 5, third metal feed line; 6, fourth metal feed line; 7, first metal shorting post; 8, second metal shorting post; 9, third metal shorting post; 10, fourth metal shorting post. DETAILED DESCRIPTION

[0034] The technical solutions of the present application will be described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0035] In the description of the present application, it should be understood that the terms "center", "upper", "lower", etc. indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", etc. are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by "first", "second", etc. can be explicitly or implicitly included one or more features. In the description of the present application, unless otherwise specified, the meaning of "multiple" is two or more.

[0036] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0037] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0038] Referring to Figures 1 to 2 The present application provides an ultra-wideband omnidirectional unmanned aerial vehicle antenna, which has a working frequency band covering 400MHz-560MHz, and specifically comprises a radiation structure, a grounding plate, a feeding structure and an air dielectric layer.

[0039] The radiation structure comprises an upper layer metal patch 1; the upper layer metal patch 1 comprises a first water-drop-shaped patch 1-1, a second water-drop-shaped patch 1-2, a third water-drop-shaped patch 1-3, a fourth water-drop-shaped patch 1-4 and a first circular patch 1-5 located in the same XOY plane; the tips of the first water-drop-shaped patch 1-1, the second water-drop-shaped patch 1-2, the third water-drop-shaped patch 1-3 and the fourth water-drop-shaped patch 1-4 are connected to the first circular patch 1-5; the first water-drop-shaped patch 1-1, the second water-drop-shaped patch 1-2, the third water-drop-shaped patch 1-3 and the fourth water-drop-shaped patch 1-4 are centrally symmetrically arranged about the center of the first circular patch 1-5; the first water-drop-shaped patch 1-1, the second water-drop-shaped patch 1-2, the third water-drop-shaped patch 1-3 and the fourth water-drop-shaped patch 1-4 are the same in size and shape and have a spacing therebetween.

[0040] The grounding plate is located below the radiation structure and has the same shape as the upper layer metal patch 1 but is larger in size than the upper layer metal patch 1; in this embodiment, the grounding plate is 1.2221 times larger in size than the upper layer metal patch 1, and both the upper layer metal patch 1 and the grounding plate are metal sheets;

[0041] The ground plate specifically comprises a fifth water-drop-shaped patch 2-1, a sixth water-drop-shaped patch 2-2, a seventh water-drop-shaped patch 2-3, an eighth water-drop-shaped patch 2-4, and a second circular patch 2-5, which are of the same size and shape; the fifth water-drop-shaped patch 2-1, the sixth water-drop-shaped patch 2-2, the seventh water-drop-shaped patch 2-3, and the eighth water-drop-shaped patch 2-4 are connected to the second circular patch 2-5 at the tips thereof; the fifth water-drop-shaped patch 2-1, the sixth water-drop-shaped patch 2-2, the seventh water-drop-shaped patch 2-3, and the eighth water-drop-shaped patch 2-4 are arranged in a central symmetry about the center of the second circular patch 2-5; and there is a spacing between the fifth water-drop-shaped patch 2-1, the sixth water-drop-shaped patch 2-2, the seventh water-drop-shaped patch 2-3, and the eighth water-drop-shaped patch 2-4.

[0042] The fifth water-drop-shaped patch 2-1, the sixth water-drop-shaped patch 2-2, the seventh water-drop-shaped patch 2-3, the eighth water-drop-shaped patch 2-4, and the second circular patch 2-5 are located directly below the first water-drop-shaped patch 1-1, the second water-drop-shaped patch 1-2, the third water-drop-shaped patch 1-3, the fourth water-drop-shaped patch 1-4, and the first circular patch 1-5, respectively.

[0043] The air medium layer is distributed between the upper layer of metal patches 1 and the ground plate.

[0044] The feeding structure penetrates the air medium layer and is connected to the upper layer of metal patches 1 and the ground plate, and specifically comprises a first metal feeding line 3, a second metal feeding line 4, a third metal feeding line 5, and a fourth metal feeding line 6.

[0045] The two ends of the first metal feeding line 3 are connected to the first water-drop-shaped patch 1-1 and the fifth water-drop-shaped patch 2-1, respectively; the two ends of the second metal feeding line 4 are connected to the second water-drop-shaped patch 1-2 and the sixth water-drop-shaped patch 2-2, respectively; the two ends of the third metal feeding line 5 are connected to the third water-drop-shaped patch 1-3 and the seventh water-drop-shaped patch 2-3, respectively; the two ends of the fourth metal feeding line 6 are connected to the fourth water-drop-shaped patch 1-4 and the eighth water-drop-shaped patch 2-4, respectively; the first water-drop-shaped patch 1-1 and the second water-drop-shaped patch 1-2 are orthogonal to each other, and the third water-drop-shaped patch 1-3 and the fourth water-drop-shaped patch 1-4 are orthogonal to each other.

[0046] The first metal shorting post 7 and the second metal shorting post 8 are arranged between the third water-drop-shaped patch 1-3 and the seventh water-drop-shaped patch 2-3; and the third metal shorting post 9 and the fourth metal shorting post 10 are arranged between the fourth water-drop-shaped patch 1-4 and the eighth water-drop-shaped patch 2-4.

[0047] The third metal feed line 5, the first metal shorting post 7 and the second metal shorting post 8 are arranged linearly from outside to inside with the center of the first circular patch 1-5 as a starting point; the distance between the first metal shorting post 7 and the second metal shorting post 8 is 1 / 124.8 of the center working frequency, and the distance between the third metal feed line 5 and the first metal shorting post 7 is 1 / 1248 of the center working frequency;

[0048] The fourth metal feed line 6, the third metal shorting post 9 and the fourth metal shorting post 10 are arranged linearly from outside to inside with the center of the first circular patch 1-5 as a starting point; the distance between the third metal shorting post 9 and the fourth metal shorting post 10 is 1 / 124.8 of the center working frequency, and the distance between the fourth metal feed line 6 and the third metal shorting post 9 is 1 / 1248 of the center working frequency;

[0049] In the embodiment, the radius of the first circular patch 1-5 is 5mm;

[0050] In the embodiment, the distance between the upper metal patch 1 and the ground plate is 1 / 15.6 of the wavelength of the center working frequency, which is 8 times of the radius of the first circular patch 1-5, i.e. 40mm, and the magnification is 1.2221;

[0051] It should be noted that, for the antenna of the application, the first metal feed line 3 and the second metal feed line 4 feed the upper metal patch 1 in phase and with equal amplitude through a coaxial line when the antenna is working; the third metal feed line 5 and the fourth metal feed line 6 do not feed and are preset with a certain impedance value, and the preset impedance value is 50Ω;

[0052] The first water-drop-shaped patch 1-1 to the fourth water-drop-shaped patch 1-4 of the upper metal patch 1 are the same in size and shape, and the edges thereof are represented by the following function:

[0053]

[0054] Wherein x is the maximum width of the water-drop-shaped patch, and y is the length of the water-drop-shaped patch.

[0055] The shapes of the first water-drop-shaped patch 1-1 to the fourth water-drop-shaped patch 1-4 of the upper metal patch 1 are gradually widened from inside to outside and then gradually narrowed, and the ends of the patches are circular arcs. The gradual change from inside to outside is from small to large and then to small, which can make the impedance matching more smooth, improve the current distribution, increase the current path, improve the impedance bandwidth of the antenna, and make the directional diagram have the omnidirectional radiation characteristics. Preferably, the length of the water-drop-shaped patch is 1 / 4 of the wavelength corresponding to the center working frequency, the widest part is 1 / 6.6 of the wavelength corresponding to the center working frequency, and the angle of the sharp end opening is 50°.

[0056] In the embodiment, the current distribution on the radiation structure is changed by adding the first metal shorting post 7, the second metal shorting post 8, the third metal shorting post 9, the fourth metal shorting post 10, the third metal feed line 5 and the fourth metal feed line 6 loaded with 50Ω between the upper metal patch 1 and the ground plate, so that the antenna is miniaturized and the resonant frequency of the antenna is reduced.

[0057] In the embodiment, the medium substrate of the antenna is selected as the simplest air medium layer, so that the influence of the general medium substrate on the antenna performance is excluded, and in the antenna design process of the application, the height of the metal feed line is selected as 40mm on the basis of maintaining the antenna gain performance.

[0058] In the application, Figure 3 、 Figure 4 a、 Figure 4 b shows the radiation performance of the bionic antenna of the application. The 400-560MHz ultra-wideband omnidirectional unmanned aerial vehicle antenna designed by the application has an impedance matching bandwidth of 400MHz-560MHz, a relative bandwidth of 33%, and maintains a relatively stable gain in the frequency band, and the radiation pattern meets the characteristics of an omnidirectional antenna.

[0059] The above describes the preferred embodiments of the application, and it should be noted that for those skilled in the art, without departing from the principles of the application, a number of improvements and refinements can be made, and these improvements and refinements are also considered within the protection scope of the application.

Claims

1. An ultra-wideband omnidirectional drone antenna with an operating frequency range of 400MHz-560MHz, including: Radiating structure; a ground plate located below the radiation structure; an air dielectric layer distributed between the upper metal patch and the ground plane; a feeding structure, which penetrates the air dielectric layer; The feeding structure includes a plurality of metal feed lines; The radiation structure includes an upper metal patch, which includes four teardrop-shaped patches and a circular patch; the four teardrop-shaped patches are symmetrically distributed about the center; the tips of the four teardrop-shaped patches are connected to the circular patch; the symmetry center of the four teardrop-shaped patches overlaps with the center of the circular patch; The ground plate has the same shape as the upper metal patch, but is larger in size than the upper metal patch; The four teardrop-shaped patches of the upper metal patch correspond one-to-one to the four teardrop-shaped patches of the ground plate, and each teardrop-shaped patch of the upper metal patch is connected to the corresponding teardrop-shaped patch of the ground plate through a metal feeder; Two metal short-circuit posts are respectively provided between two adjacent teardrop-shaped patches of the upper metal patch and the corresponding teardrop-shaped patches of the ground plate; The two metal feed lines on the two teardrop-shaped patches without metal short-circuit posts are fed with the same phase and amplitude; The two metal feed lines on the two teardrop-shaped patches provided with metal short-circuit posts do not feed power, and both of the metal feed lines are loaded with resistors.

2. The ultra-wideband omnidirectional UAV antenna according to claim 1, characterized in that: The size of the ground plate is 1.2-1.3 times larger than that of the upper metal patch.

3. The ultra-wideband omnidirectional UAV antenna according to claim 1, characterized in that: The distance between the upper metal patch and the ground plane is 1 / 15-1 / 16 of the wavelength of the central operating frequency.

4. The ultra-wideband omnidirectional UAV antenna according to claim 1, characterized in that: The distance between the upper metal patch and the ground plate is 7-8 times the circular patch radius of the upper metal patch.

5. The ultra-wideband omnidirectional UAV antenna according to claim 1, characterized in that: The resistance value of the metal feed line loaded with the resistor is 50Ω.

6. The ultra-wideband omnidirectional UAV antenna according to claim 1, characterized in that: On a teardrop-shaped patch provided with metal short-circuit posts, a metal feeder and two metal short-circuit posts are arranged from outside to inside along the central axis of the teardrop-shaped patch.

7. The ultra-wideband omnidirectional UAV antenna according to claim 6, characterized in that: On a teardrop-shaped patch with metal short-circuit posts, the distance between two metal short-circuit posts is 1 / 124-1 / 125 of the center operating frequency, and the distance between the metal feeder on the current teardrop-shaped patch and the nearest metal short-circuit post is 1 / 1247-1 / 1249 of the center operating frequency.

8. The ultra-wideband omnidirectional UAV antenna according to claim 1, characterized in that: The teardrop-shaped patch of the upper metal patch shows a trend of gradually widening and then gradually narrowing from the inside to the outside, and the end of the patch is in an arc shape.

9. The ultra-wideband omnidirectional UAV antenna according to claim 8, characterized in that: The teardrop-shaped patch of the upper metal patch has a length of 1 / 4 of the wavelength corresponding to the central operating frequency, a widest point of 1 / 6-1 / 7 of the wavelength corresponding to the central operating frequency, and an angle of the tip opening of 50°.

10. The ultra-wideband omnidirectional UAV antenna according to claim 1, characterized in that: The patches connected by the two metal feed lines for feeding power are orthogonal to each other; the patches connected by the two metal feed lines for not feeding power are orthogonal to each other.

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