Dual-frequency antenna and unmanned aerial vehicle

Abstract

The embodiment of the present invention relates to the technical field of unmanned aerial vehicle antennas, and discloses a dual-frequency antenna and an unmanned aerial vehicle, including a substrate; a monopole vibrator having a first resonant frequency, the monopole vibrator is arranged on the substrate, and includes a first radiating portion and a second radiating portion, the first radiating portion and the second radiating portion are respectively located at two opposite sides of a feeding point of the monopole vibrator; a dipole vibrator having a second resonant frequency, the dipole vibrator is arranged on the substrate, and is located between the first radiating portion and the second radiating portion; and a feeding coaxial line, the feeding end of which is respectively connected to the feeding point of the monopole vibrator and the feeding point of the dipole vibrator, and the grounding end of the feeding coaxial line is connected to the grounding end of the dipole vibrator. Therefore, the dual-frequency antenna is installed in the unmanned aerial vehicle, and can be accommodated in the landing gear while ensuring the quality of mission information transmission, meeting the built-in space size requirements, and is conducive to the miniaturization design of the unmanned aerial vehicle.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicle antennas, and in particular to a dual-frequency antenna and an unmanned aerial vehicle. Background Art

[0002] Unmanned aerial vehicle is an unmanned aerial vehicle that is controlled by radio remote control equipment and self-contained program control devices. As an important part of the unmanned aerial vehicle system, the wireless communication link system is used to establish a two-way data transmission channel between air and ground to complete the long-distance remote control, telemetry and mission information transmission of the ground control station to the UAV.

[0003] The existing wireless communication link system is generally divided into an airborne part and a ground part. The airborne part includes an airborne data terminal (ADT) and an antenna. The airborne data terminal includes an RF receiver, a transmitter, and a modem for connecting the receiver and transmitter to other parts of the system. The ground part is also called a ground data terminal (GDT), which includes one or more antennas, an RF receiver and transmitter, and a modem.

[0004] In the process of realizing the present invention, the inventors found that existing unmanned aerial vehicles usually have dual-frequency antennas built into the landing gear. In order to ensure the quality of mission information transmission, the dual-frequency antenna will inevitably increase in size. However, the antenna is too large and difficult to be accommodated in the landing gear, which is not conducive to the miniaturization design of the unmanned aerial vehicle. Summary of the invention

[0005] The embodiments of the present invention aim to provide a dual-frequency antenna and an unmanned aerial vehicle to solve the problem that the existing dual-frequency antenna has an excessively large antenna volume in order to ensure the quality of mission information transmission.

[0006] In order to solve the above technical problems, a technical solution adopted in the embodiment of the present invention is: to provide a dual-frequency antenna, comprising:

[0007] substrate;

[0008] A monopole oscillator having a first resonant frequency, the monopole oscillator being disposed on the substrate, and comprising a first radiating portion and a second radiating portion electrically connected to each other, the first radiating portion and the second radiating portion being respectively located at two opposite sides of a feeding point of the monopole oscillator;

[0009] A dipole oscillator having a second resonant frequency, the dipole oscillator being arranged on the substrate, and comprising a third radiating portion and a fourth radiating portion electrically connected to each other, the third radiating portion being located at an end of the first radiating portion close to a feeding point of the monopole oscillator, and the fourth radiating portion being located at an end of the second radiating portion close to a feeding point of the monopole oscillator; and

[0010] A feeding coaxial line, wherein a feeding end thereof is respectively connected to a feeding point of the monopole and a feeding point of the dipole, and a grounding end of the feeding coaxial line is connected to a grounding end of the dipole.

[0011] Optionally, the first radiating portion includes a first arm, a first sub-radiating portion and a second sub-radiating portion; the first arm is connected to the second radiating portion, and opposite ends of the first arm are respectively connected to the first sub-radiating portion and the second sub-radiating portion.

[0012] Optionally, the first sub-radiating portion and the second sub-radiating portion are arranged in mirror symmetry.

[0013] Optionally, the first sub-radiating portion includes a second arm and a third arm; the second arm is formed by extending an end of the first arm away from the third radiating portion along an axial direction perpendicular to the first arm; the third arm is formed by bending and extending an end of the second arm away from the first arm.

[0014] Optionally, the angle between the third vibration arm and the second vibration arm is a right angle or an obtuse angle.

[0015] Optionally, the second radiating portion includes a fourth arm, a third sub-radiating portion and a fourth sub-radiating portion; the fourth arm is connected to the first arm, and opposite ends of the fourth arm are respectively connected to the third sub-radiating portion and the fourth sub-radiating portion.

[0016] Optionally, the third sub-radiating portion and the fourth sub-radiating portion are arranged in mirror symmetry.

[0017] Optionally, the third sub-radiating portion includes a fifth arm, a sixth arm, a seventh arm and an eighth arm; the fifth arm is formed by extending the end of the fourth arm away from the first arm along an axial direction perpendicular to the first arm; the sixth arm is formed by bending and extending the end of the fifth arm away from the fourth arm along an axial direction parallel to the first arm; the seventh arm is formed by bending and extending the end of the sixth arm away from the fifth arm along an axial direction perpendicular to the first arm; the eighth arm is formed by bending and extending the end of the seventh arm away from the sixth arm.

[0018] Optionally, the angle between the seventh vibration arm and the eighth vibration arm is a right angle or an obtuse angle.

[0019] Optionally, the first radiating portion, the second radiating portion, the third radiating portion and the fourth radiating portion are coaxially arranged along the longitudinal axis of the substrate.

[0020] Optionally, a feeding hole is provided on the substrate; the feeding hole is located in an overlapping area of ​​the first radiating portion and the third radiating portion, and the feeding point of the monopole and the feeding point of the dipole are both coaxially arranged with the feeding hole.

[0021] Optionally, the second radiating portion and the fourth radiating portion are arranged to at least partially overlap.

[0022] Optionally, the substrate is provided with a first notch and a second notch; the first notch is located in an area enclosed by the first radiating portion and the third radiating portion; the second notch is located in an area enclosed by the second radiating portion and the fourth radiating portion.

[0023] Optionally, the first resonant frequency is 900 MHz, and the second resonant frequency is 2.4 GHz.

[0024] Optionally, the dual-band antenna further includes a barrier; the barrier is disposed between the feeding coaxial line and the substrate, and the barrier is used to increase the gap between the feeding coaxial line and the substrate.

[0025] In order to solve the above technical problems, another technical solution adopted by the embodiment of the present invention is: to provide an unmanned aerial vehicle, comprising:

[0026] a fuselage, provided with landing gear;

[0027] A driving assembly, comprising a motor and a propeller, wherein the motor is mounted on the machine body, and the propeller is mounted on the motor;

[0028] A flight control system is installed on the fuselage, the flight control system is in communication connection with the motor, and is used to control the motor to drive the propeller to rotate;

[0029] The dual-frequency antenna as described above is installed in the landing gear, and the dual-frequency antenna is communicatively connected with the flight control system.

[0030] The beneficial effects of the embodiments of the present invention are as follows: different from the prior art, the dual-frequency antenna and unmanned aerial vehicle provided by the present invention achieve the best impedance matching of the dual-frequency antenna by adjusting the layout of the monopole vibrator and the dipole vibrator on the substrate. The simulation results show that the E-plane radiation pattern and the H-plane radiation pattern of the antenna at the first resonant frequency f1=900MHz and the second resonant frequency f2=2.4GHz can basically achieve omnidirectional coverage. While ensuring the quality of mission information transmission, it can also be accommodated in the landing gear, meet the built-in space size requirements, and are conducive to the miniaturized design of the unmanned aerial vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without paying creative work.

[0032] Figure 1 A schematic diagram of the structure of an unmanned aerial vehicle provided by one embodiment of the present invention;

[0033] Figure 2 for Figure 1 A schematic block diagram of each module of the unmanned aerial vehicle shown;

[0034] Figure 3 for Figure 1 A schematic diagram of the structure of a dual-frequency antenna for an unmanned aerial vehicle shown;

[0035] Figure 4 for Figure 3 A structural schematic diagram of another installation method of the feeder of the dual-frequency antenna shown;

[0036] Figure 5 for Figure 3 A schematic diagram of an alternative manner of the first radiating portion in the dual-band antenna shown;

[0037] Figure 6 for Figure 3 Schematic diagram of scattering parameters of dual-frequency antenna shown;

[0038] Figure 7 for Figure 3 900MHz antenna pattern of the dual-band antenna shown;

[0039] Figure 8 for Figure 3 2.4 GHz antenna pattern of the dual-band antenna shown;

[0040] Fig. 9 A schematic diagram of the structure of a dual-frequency antenna provided by another embodiment of the present invention;

[0041] Fig.10 A schematic diagram of the structure of a dual-frequency antenna provided by another embodiment of the present invention;

[0042] Fig.11 A schematic diagram of the structure of a dual-frequency antenna provided by another embodiment of the present invention;

[0043] Fig.12 A schematic diagram of the structure of a dual-frequency antenna provided by another embodiment of the present invention;

[0044] Fig.13A schematic diagram of the structure of a dual-frequency antenna provided by another embodiment of the present invention;

[0045] Fig.14 A schematic diagram of the structure of a dual-frequency antenna provided by another embodiment of the present invention;

[0046] Fig.15 A schematic diagram of the structure of a dual-frequency antenna provided in another embodiment of the present invention. DETAILED DESCRIPTION

[0047] In order to facilitate the understanding of the present invention, the present invention is described in more detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that when an element is described as "fixed to" / "fixed to" another element, it can be directly on the other element, or there can be one or more centered elements therebetween. When an element is described as "connected to" another element, it can be directly connected to the other element, or there can be one or more centered elements therebetween. The terms "vertical", "horizontal", "left", "right", "inside", "outside" and similar expressions used in this specification are for illustrative purposes only.

[0048] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items.

[0049] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0050] The dual-frequency antenna provided in the embodiment of the present invention can be applied to unmanned aerial vehicles. The unmanned aerial vehicles in the embodiment of the present invention can be applied to military and civilian scenarios. Civilian scenarios include, for example, aerial photography, express delivery, disaster relief, wildlife observation, surveying and mapping, news reporting, power inspection and other application scenarios.

[0051] Among them, unmanned aerial vehicles may include fixed-wing unmanned aerial vehicles and rotary-wing unmanned aerial vehicles, such as helicopters, quadcopters and aircraft with other numbers of rotors and / or rotor configurations. Unmanned aerial vehicles can be used to track targets, and obstacles may be encountered during the process of unmanned aerial vehicles tracking targets. Unmanned aerial vehicles need to track targets while avoiding obstacles to achieve normal flight. Among them, the target can be any suitable movable or immovable object, including vehicles, people, animals, buildings, mountains and rivers, etc. Obstacles such as buildings, mountains, trees, forests, signal towers or other movable or immovable objects.

[0052] For ease of explanation, the present invention takes the installation of a dual-frequency antenna on a fixed-wing unmanned aerial vehicle as an example. It should be understood that the following description is only exemplary and does not limit the patent scope of the present invention.

[0053] Please also read Figure 1 as well as Figure 2 , a fixed-wing unmanned aerial vehicle provided by the present invention, includes a body 10, a driving component 20, a flight control system 30 and a dual-frequency antenna 40.

[0054] Specifically, the fuselage 10 includes a fuselage 110, a wing 120, and a tail 130. The wing 120 is arranged on one side of the fuselage 110. Preferably, there are two wings 120, which are arranged on two opposite sides of the fuselage 110, respectively. A drive assembly 20 is installed at one end of the wing 120 away from the fuselage 110. The drive assembly 20 includes a motor 210 and a propeller 220. The stator of the motor 210 is fixed to the end of the wing 120 away from the fuselage 110, and the propeller 220 is installed on the rotor of the motor 210. The tail 130 is arranged at the tail of the fuselage 110. 10 is provided with a landing gear 111, which is used to support the fuselage 110. The dual-frequency antenna 40 is installed in the landing gear 111. An installation space (not shown) is provided in the fuselage 110, and the installation space is used to accommodate and fix the flight control system 30. The flight control system 30 is respectively communicated with the motor 210 and the dual-frequency antenna 40. The flight control system 30 is used to control the motor 210 to provide flight power for the unmanned aerial vehicle, and to send and receive control signals of the ground data terminal through the dual-frequency antenna 40.

[0055] To facilitate the fixed-wing unmanned aerial vehicle to collect image data during flight, optionally, the fixed-wing unmanned aerial vehicle also includes an aerial photography gimbal 50, which is installed on the head of the fuselage 110 and is communicatively connected to the dual-frequency antenna 40. The aerial photography gimbal 50 transmits image data to a ground data terminal via the dual-frequency antenna 40.

[0056] It is worth noting that due to the size limitation of the landing gear 111 of the traditional fixed-wing unmanned aerial vehicle, it can only accommodate high-frequency microstrip antennas such as 2.4GHz. In order to install the low-frequency dual-band antenna 40 in the landing gear 111, the shape of the landing gear 111 is also changed from the original straight strip to the current outward bow shape. While increasing the length of the landing gear 111, it also makes the fuselage 110 have good support.

[0057] Please also read Figure 3 and Figure 4 The dual-frequency antenna 40 includes a substrate 410 , a monopole 420 having a first resonant frequency, a dipole 430 having a second resonant frequency, and a feeding coaxial line 440 .

[0058] The substrate 410 is accommodated in the landing gear 111, and the monopole 420 and the dipole 430 are both arranged on the substrate 410. The monopole 420 includes a first radiating portion 420a and a second radiating portion 420b which are electrically connected to each other. The first radiating portion 420a and the second radiating portion 420b are respectively located at two opposite sides of a feeding point of the monopole 420, and the dipole 430 is located between the first radiating portion 420a and the second radiating portion 420b, wherein the feeding point of the monopole 420 and the feeding point of the dipole 430 are respectively connected to the feeding end of the feeding coaxial line 440, and the feeding coaxial line 440 is far away from one end of the substrate 410, that is, the other end opposite to the feeding end of the feeding coaxial line 440 is connected to the flight control system 30.

[0059] By adjusting the layout of the monopole 420 and the dipole 430 on the substrate 410 to achieve optimal impedance matching of the dual-band antenna 40, while ensuring the quality of mission information transmission, it can also be accommodated in the landing gear 111, meeting the built-in space size requirements, which is conducive to the miniaturization design of the unmanned aerial vehicle.

[0060] For the above substrate 410, please continue to refer to Figure 3 The substrate 410 is roughly in the shape of a rectangular plate. Specifically, a feeding hole (not shown) is provided on the substrate 410. The feeding hole is used for inserting and fixing a feeding probe of the feeding coaxial line 440 to feed the monopole 420 and the dipole 430 respectively.

[0061] In order to reduce the difference and variation in the performance of the dual-band antenna 40, the substrate 410 may optionally use a material medium with a relatively small dielectric constant. For example, the substrate 410 is made of a FR-4 grade material, wherein FR-4 is a code for a flame retardant material grade, which means that the resin material must be able to extinguish itself after burning. It is not a material name, but a material grade. Therefore, there are many types of FR-4 grade materials used in the general substrate 410, but most of them are composite materials made of so-called tera-function epoxy resin plus filler (Filler) and glass fiber. It should be understood that according to the actual design requirements and the needs of manufacturing costs, the substrate 410 can also be made of other materials, such as plastic, foam, etc., and have a non-conductive structure with a specific shape.

[0062] For the first radiating portion 420a of the monopole 420, please continue to refer to Figure 3The first radiating portion 420a includes a first arm 421, a first sub-radiating portion 422 and a second sub-radiating portion 423. The first arm 421 extends from the feeding hole toward an end of the substrate 410 away from the body 110 along a direction parallel to the longitudinal axis of the substrate 410. Preferably, the first arm 421 is collinear with a symmetry line of the substrate 410 parallel to the longitudinal axis. An end of the first arm 421 close to the feeding hole is connected to the second radiating portion 420b, and an end of the first arm 421 away from the feeding hole is connected to the first sub-radiating portion 422 and the second sub-radiating portion 423, respectively.

[0063] It is worth noting that the second sub-radiating portion 423 and the first sub-radiating portion 422 are arranged in mirror symmetry, which means that the second sub-radiating portion 423 and the first sub-radiating portion 422 are axially symmetric with respect to the first arm 421. In other words, the second sub-radiating portion 423 can be considered to be the first sub-radiating portion 422 flipped along the first arm 421, so the structure of the second sub-radiating portion 423 can refer to the first sub-radiating portion 422, and no further description is given here.

[0064] Specifically, the first sub-radiating portion 422 includes a second arm 4221 and a third arm 4222. The second arm 4221 is formed by extending one end of the first arm 421 away from the feeding hole toward one side of the substrate 410 in a direction perpendicular to the longitudinal axis of the substrate 410, and the third arm 4222 is formed by bending and extending one end of the second arm 4221 away from the first arm 421, and the third arm 4222 is arranged at an angle to the second arm 4221.

[0065] It should be understood that in the embodiment of the present invention, the first radiating portion 420a resonates by using the wiring method of the vibration arm, but in other embodiments of the present invention, please refer to Figure 5 The first radiating portion 420a may also be replaced by a microstrip with a larger area, which has the same resonance effect as the vibration arm.

[0066] To avoid mutual interference between the signals of the first vibration arm 421 and the third vibration arm 4222, preferably, the distance between the first vibration arm 421 and the third vibration arm 4222 is greater than the signal interference distance between the two. For example, in the embodiment of the present invention, please refer to Figure 3 as well as Fig. 9 , the third arm 4222 is arranged at a right angle to the second arm 4221, the end of the third arm 4222 away from the second arm 4221 points to the second radiating portion 420b or to the end of the substrate 410 close to the fuselage 110, and the distance between the first arm 421 and the third arm 4222 is the distance between the two ends of the first arm 421, which is greater than the signal interference distance between the two. It should be understood that in another embodiment of the present invention, please refer to Fig.10The third vibration arm 4222 is set at an obtuse angle with the second vibration arm 4221, that is, the end of the third vibration arm 4222 away from the second vibration arm 4221 points to the side of the substrate 410. At this time, the distance between the first vibration arm 421 and the third vibration arm 4222 is the distance between the end of the third vibration arm 4222 close to the second vibration arm 4221 and the first vibration arm 421, which is greater than the signal interference distance between the two.

[0067] For the second radiating portion 420b of the monopole 420, the second radiating portion 420b includes a fourth arm 424, a third sub-radiating portion 425 and a fourth sub-radiating portion 426. The fourth arm 424 extends from the feeding hole toward an end of the substrate 410 close to the fuselage 110 along a longitudinal direction parallel to the substrate 410. Preferably, the fourth arm 424 is colinear with a symmetry line of the substrate 410 parallel to the longitudinal direction. An end of the fourth arm 424 close to the feeding hole is connected to an end of the first arm 421 close to the feeding hole. An end of the fourth arm 424 away from the feeding hole is connected to the third sub-radiating portion 425 and the fourth sub-radiating portion 426 respectively.

[0068] It is worth noting that the third sub-radiating portion 425 and the fourth sub-radiating portion 426 are arranged in mirror symmetry, which means that the third sub-radiating portion 425 and the fourth sub-radiating portion 426 are axially symmetric with respect to the fourth swing arm 424. In other words, the fourth sub-radiating portion 426 can be considered to be the third sub-radiating portion 425 flipped along the fourth swing arm 424, and thus the structure of the fourth sub-radiating portion 426 can refer to the third sub-radiating portion 425, which will not be described in detail here.

[0069] Specifically, the third sub-radiating portion 425 includes a fifth arm 4251 , a sixth arm 4252 , a seventh arm 4253 and an eighth arm 4254 . The fifth arm 4251 is formed by extending one end of the fourth arm 424 away from the feeding hole toward one side of the substrate 410 along a direction perpendicular to the longitudinal axis of the substrate 410, the sixth arm 4252 is formed by extending one end of the fifth arm 4251 away from the fourth arm 424 along a direction parallel to the longitudinal axis of the substrate 410 toward one end of the substrate 410 close to the fuselage 110, the seventh arm 4253 is formed by extending one end of the sixth arm 4252 away from the fifth arm 4251 toward one side of the substrate 410 along a direction perpendicular to the longitudinal axis of the substrate 410, and the extension direction of the seventh arm 4253 is the same as the extension direction of the fifth arm 4251, and the eighth arm 4254 is formed by bending and extending one end of the seventh arm 4253 away from the sixth arm 4252, and the eighth arm 4254 is arranged at an angle to the seventh arm 4253.

[0070] To avoid mutual interference between the signals of the sixth vibration arm 4252 and the eighth vibration arm 4254, preferably, the distance between the sixth vibration arm 4252 and the eighth vibration arm 4254 is greater than the signal interference distance between the sixth vibration arm 4252 and the eighth vibration arm 4254. For example, in the embodiment of the present invention, please continue to refer to Figure 3 as well as Fig. 9 , the sixth arm 4252, the seventh arm 4253 and the eighth arm 4254 are arranged at right angles, the end of the eighth arm 4254 away from the seventh arm 4253 points to the first radiation portion 420a or to the end of the substrate 410 away from the body 110, and the distance between the eighth arm 4254 and the sixth arm 4252 is the distance between the two ends of the seventh arm 4253, which is greater than the signal interference distance between the two. It should be understood that in another embodiment of the present invention, please continue to refer to Fig.10 , the eighth arm 4254 and the seventh arm 4253 are arranged at an obtuse angle, that is, the end of the eighth arm 4254 away from the seventh arm 4253 points to the side of the substrate 410, and the distance between the eighth arm 4254 and the sixth arm 4252 is the distance between the end of the eighth arm 4254 close to the seventh arm 4253 and the sixth arm 4252, which is greater than the signal interference distance between the two. In addition, in order to avoid mutual interference between the feeding coaxial cable and the second radiating portion 420b during signal transmission, preferably, the distance between the sixth arm 4252 and the feeding coaxial cable 440 is greater than the signal interference distance between the two.

[0071] To ensure that the monopole 420 has good antenna gain, preferably, the total length of the first arm 421 and the first sub-radiating portion 422 and the total length of the fourth arm 424 and the third sub-radiating portion 425 are controlled within a length range of 1 / 8 to 3 / 4 of the first resonant frequency wavelength.

[0072] For the above mentioned dipole oscillator 430, please continue Figure 4 The dipole element 430 includes a third radiating portion 430a and a fourth radiating portion 430b which are electrically connected to each other. The third radiating portion 430a is located at one end close to the first radiating portion 420a, and the third radiating portion 430a at least partially overlaps with an end of the first arm 421 close to the feeding hole, and the fourth radiating portion 430b is located at one end close to the second radiating portion 420b, and the fourth radiating portion 430b at least partially overlaps with the fourth arm 424.

[0073] It is worth noting that the third radiating portion 430a and the fourth radiating portion 430b are arranged in mirror symmetry, which means that the third radiating portion 430a and the fourth radiating portion 430b are axially symmetric relative to the symmetry axis parallel to the substrate 410. In other words, the fourth radiating portion 430b can be considered to be the third radiating portion 430a flipped along the fourth vibration arm 424.

[0074] Specifically, the third radiating portion 430a includes a fifth sub-radiating portion 431 and a sixth sub-radiating portion 432, and the fifth sub-radiating portion 431 and the sixth sub-radiating portion 432 are axially symmetrically arranged along the symmetry axis of the substrate 410. Optionally, the fifth sub-radiating portion 431 includes a ninth swing arm 4311 and a tenth swing arm 4312. The ninth swing arm 4311 is formed by extending from one end of the first swing arm 421 close to the feeding hole toward one side of the substrate 410 along a direction perpendicular to the longitudinal axis of the substrate 410, and the length of the ninth swing arm 4311 is the same as the length of the second swing arm 4221, or the total length of the fifth swing arm 4251 and the seventh swing arm 4253. The tenth swing arm 4312 is formed by bending and extending from one end of the ninth swing arm 4311 away from the first swing arm 421, and the tenth swing arm 4312 is arranged at an angle with the ninth swing arm 4311.

[0075] In order to avoid mutual interference between the signals of the tenth vibration arm 4312 and the first vibration arm 421, preferably, the distance between the tenth vibration arm 4312 and the first vibration arm 421 is greater than the signal interference distance between the two. For example, in an embodiment of the present invention, the tenth vibration arm 4312 is arranged at a right angle to the ninth vibration arm 4311, wherein one end of the tenth vibration arm 4312 away from the ninth vibration arm 4311 points to the third vibration arm 4222, and the distance between the tenth vibration arm 4312 and the first vibration arm 421 is the distance between the two ends of the ninth vibration arm 4311, which is greater than the signal interference distance between the two.

[0076] The fourth radiating portion 430b includes a seventh sub-radiating portion 433 and an eighth radiating portion, and the seventh sub-radiating portion 433 and the eighth sub-radiating portion 434 are arranged axially symmetrically along the symmetry axis of the substrate 410. Optionally, the seventh sub-radiating portion 433 includes an eleventh arm 4331 and a twelfth arm 4332. The eleventh arm 4331 is formed by extending from one end of the fourth arm 424 close to the feeding hole toward one side of the substrate 410 along a direction perpendicular to the longitudinal axis of the substrate 410, and the eleventh arm 4331 at least partially overlaps with the fifth arm 4251, and the twelfth arm 4332 is formed by bending and extending from one end of the eleventh arm 4331 away from the fourth arm 424, and the twelfth arm 4332 is arranged at an angle with the eleventh arm 4331.

[0077] In order to avoid mutual interference between the signals of the twelfth vibration arm 4332 and the sixth vibration arm 4252, preferably, the distance between the twelfth vibration arm 4332 and the sixth vibration arm 4252 is greater than the signal interference distance between the two. For example, in the embodiment of the present invention, the twelfth vibration arm 4332 and the eleventh vibration arm 4331 are arranged at a right angle, wherein the end of the twelfth vibration arm 4332 away from the eleventh vibration arm 4331 points to the eighth vibration arm 4254, and the distance between the twelfth vibration arm 4332 and the sixth vibration arm 4252 is the length of the portion of the eleventh vibration arm 4331 that does not overlap with the fifth vibration arm 4251, and the length is greater than the signal interference distance between the two.

[0078] To ensure that the dipole element 430 has good antenna gain, preferably, the total length of the ninth arm 4311 and the tenth arm 4312 and the total length of the eleventh arm 4331 and the twelfth arm 4332 are both controlled within a length range of 1 / 8 to 3 / 4 of the wavelength of the second resonant frequency.

[0079] For the above-mentioned feeding coaxial line 440, the feeding coaxial line 440 includes an inner conductor (not shown), an outer conductor (not shown) and a shielding layer (not shown) which are coaxially arranged. Among them, the end of the feeding coaxial line away from the flight control system 30 is installed in the feeding hole in the form of a probe, the part where the probe is connected to the outer conductor is electrically connected to the feeding point of the monopole 420, the part where the probe is connected to the inner conductor is electrically connected to the feeding point of the dipole 430, and the part where the probe is connected to the shielding layer is electrically connected to the grounding end of the dipole 430. It is worth noting that the feeding point of the monopole 420, the feeding point of the dipole 430 and the grounding end of the dipole 430 are all coaxially arranged with the feeding hole.

[0080] To facilitate adjustment of the resonance waveform of the monopole oscillator 420 and / or the dipole oscillator 430, optionally, a first notch 411 and a second notch 412 are respectively provided on the substrate 410. Fig.11 , Fig.12 as well as Fig.13 , the first notch 411 is located in the area enclosed by the first radiation part 420a and the third radiation part 430a, and the second notch 412 is located in the area enclosed by the second radiation part 420b and the fourth radiation part 430b. Specifically, there are two first notches 411 and two second notches 412. One first notch 411 is located between the first sub-radiation part 422 and the third radiation part 430a, another first notch 411 is located between the second sub-radiation part 423 and the third radiation part 430a, one second notch 412 is located between the third sub-radiation part 425 and the fourth radiation part 430b, and another second notch 412 is located between the fourth sub-radiation part 426 and the fourth radiation part 430b. Further, the shapes of the first notch 411 and the second notch 412 are any one of an inverted T-shape, an L-shape, and an inverted L-shape.

[0081] It should be understood that in other embodiments of the present invention, please refer to Fig.14 The first notch 411 and the second notch 412 can be replaced by a first opening 411 and a second opening 412 . For example, the first opening 411 and the second opening 412 are in a straight line shape.

[0082] In order to reduce the signal interference of the feeding coaxial line 440 on the resonance wave emitted by the monopole 420 and / or the dipole 430 during signal transmission, in other embodiments of the present invention, please refer to Fig.15 The dual-frequency antenna 40 further includes a barrier 60, which is disposed between the feed coaxial line 440 and the surface of the substrate 410, and is used to increase the gap between the feed coaxial line 440 and the substrate 410, which can effectively improve the influence of signal interference. Further, the barrier 60 can be a non-conductive material, such as foam or colloid, which can fix the coaxial line while increasing the gap between the feed coaxial line 440 and the substrate 410.

[0083] See also Figure 6 , which is a schematic diagram of the S parameters of the dual-frequency antenna 40 provided in the embodiment of the present invention in the low frequency band and the high frequency band. The dual-frequency antenna 40 can operate in the first resonant frequency band of 870MHz to 940MHz (low frequency band) and the second resonant frequency band of 2.36GHz to 3GHz (high frequency band). Therefore, coverage of the two frequency bands of the first resonant frequency of 900MHz and the second resonant frequency of 2.4GHz can be achieved. It should be understood that the monopole 420 and the dipole 430 in the embodiment of the present invention can also operate in two other different frequency bands.

[0084] Figure 7 and Figure 8 The antenna directional diagrams of the dual-frequency antenna 40 provided in the embodiment of the present invention in the low frequency band and the high frequency band are shown respectively. Figure 7 and Figure 8 As shown, the antenna provided by the embodiment of the present invention has good directivity in both low frequency band and high frequency band, good omnidirectionality, and no defects in a specific direction.

[0085] In an embodiment of the present invention, the layout of the monopole 420 and the dipole 430 on the substrate 410 is adjusted to achieve optimal impedance matching of the dual-band antenna 40. Simulation results show that the E-plane radiation pattern and the H-plane radiation pattern of the antenna at the first resonant frequency f1=900MHz and the second resonant frequency f2=2.4GHz can basically achieve omnidirectional coverage. While ensuring the quality of mission information transmission, it can also be accommodated in the landing gear 111, meeting the built-in space size requirements, which is conducive to the miniaturization design of the unmanned aerial vehicle.

[0086] The above description is only an implementation mode of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A dual-band antenna, characterized in that: include: substrate; A monopole vibrator having a first resonant frequency and disposed on the substrate, wherein the monopole vibrator comprises a first radiating portion and a second radiating portion electrically connected to each other, wherein the first radiating portion and the second radiating portion are respectively located at two opposite sides of a feeding point of the monopole vibrator; A dipole oscillator having a second resonant frequency and disposed on the substrate, the dipole oscillator comprising a third radiating portion and a fourth radiating portion electrically connected to each other, the third radiating portion being located at an end of the first radiating portion close to a feeding point of the monopole oscillator, and the fourth radiating portion being located at an end of the second radiating portion close to a feeding point of the monopole oscillator; and A feeding coaxial line, wherein the feeding end of the feeding coaxial line is respectively connected to the feeding point of the monopole and the feeding point of the dipole, and the grounding end of the feeding coaxial line is connected to the grounding end of the dipole; The first radiating portion includes a first vibration arm, a first sub-radiating portion and a second sub-radiating portion; The first vibration arm is connected to the second radiation part, and two opposite ends of the first vibration arm are respectively connected to the first sub-radiation part and the second sub-radiation part; The second radiating portion includes a fourth arm, a third sub-radiating portion and a fourth sub-radiating portion; The fourth vibration arm is connected to the first vibration arm, and two opposite ends of the fourth vibration arm are respectively connected to the third sub-radiating portion and the fourth sub-radiating portion; The first sub-radiating portion and the second sub-radiating portion are arranged in a mirror-symmetrical manner; the third sub-radiating portion and the fourth sub-radiating portion are arranged in a mirror-symmetrical manner; The third radiating portion and the fourth radiating portion are arranged in a mirror-symmetrical manner; The third radiation portion includes a fifth sub-radiation portion and a sixth sub-radiation portion, and the fifth sub-radiation portion and the sixth sub-radiation portion are axially symmetrically arranged along the symmetry axis of the substrate; The fourth radiation portion includes a seventh sub-radiation portion and an eighth sub-radiation portion, and the seventh sub-radiation portion and the eighth sub-radiation portion are axially symmetrically arranged along the symmetry axis of the substrate.

2. The dual-band antenna according to claim 1, characterized in that: The first sub-radiating portion includes a second arm and a third arm; The second vibration arm is formed by extending an end of the first vibration arm away from the third radiation portion along an axial direction perpendicular to the first vibration arm; The third vibrating arm is formed by bending and extending one end of the second vibrating arm away from the first vibrating arm.

3. The dual-band antenna according to claim 2, characterized in that: The angle between the third vibration arm and the second vibration arm is a right angle or an obtuse angle.

4. The dual-band antenna according to claim 1, characterized in that: The third sub-radiating portion includes a fifth arm, a sixth arm, a seventh arm and an eighth arm; The fifth vibration arm is formed by extending one end of the fourth vibration arm away from the first vibration arm along an axis direction perpendicular to the first vibration arm; The sixth vibration arm is formed by bending and extending one end of the fifth vibration arm away from the fourth vibration arm along an axis direction parallel to the first vibration arm; The seventh vibration arm is formed by bending and extending one end of the sixth vibration arm away from the fifth vibration arm along an axial direction perpendicular to the first vibration arm; The eighth vibrating arm is formed by bending and extending one end of the seventh vibrating arm away from the sixth vibrating arm.

5. The dual-band antenna according to claim 4, characterized in that: The angle between the seventh vibration arm and the eighth vibration arm is a right angle or an obtuse angle.

6. The dual-frequency antenna according to any one of claims 1 to 5, characterized in that: The first radiating portion, the second radiating portion, the third radiating portion, and the fourth radiating portion are coaxially arranged along a longitudinal axis of the substrate.

7. The dual-band antenna according to claim 6, characterized in that: A feeding hole is provided on the substrate; The feeding hole is located in an overlapping area of ​​the first radiating portion and the third radiating portion, and a feeding point of the monopole and a feeding point of the dipole are both coaxially arranged with the feeding hole.

8. The dual-band antenna according to claim 7, characterized in that: The second radiating portion and the fourth radiating portion are at least partially overlapped.

9. The dual-frequency antenna according to any one of claims 1 to 5, characterized in that: The substrate is provided with a first notch and a second notch; The first notch is located in an area enclosed by the first radiation portion and the third radiation portion; The second notch is located in a region enclosed by the second radiation portion and the fourth radiation portion.

10. The dual-frequency antenna according to any one of claims 1 to 5, characterized in that: The first resonant frequency is 900 MHz, and the second resonant frequency is 2.4 GHz.

11. The dual-frequency antenna according to any one of claims 1 to 5, characterized in that: The dual-frequency antenna also includes a barrier; The barrier is disposed between the feeding coaxial line and the substrate, and is used to increase the gap between the feeding coaxial line and the substrate.

12. An unmanned aerial vehicle, characterized in that: include: a fuselage, provided with landing gear; A driving assembly, comprising a motor and a propeller, wherein the motor is mounted on the machine body, and the propeller is mounted on the motor; A flight control system is installed on the body, the flight control system is in communication with the motor and is used to control the motor to drive the propeller to rotate; The dual-frequency antenna according to any one of claims 1 to 11, wherein the dual-frequency antenna is installed in the landing gear, and the dual-frequency antenna is communicatively connected to the flight control system.

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