An amplitude comparison direction-finding antenna array and an anti-UAV passive direction-finding and positioning system

Abstract

The present invention discloses an amplitude comparison direction-finding antenna array and an anti-drone passive direction-finding and positioning system. The amplitude comparison direction-finding antenna array includes four antenna devices, and two adjacent antenna devices are arranged vertically to form an antenna array. The antenna device includes a reflector, a PCB board, and a pair of radiation arms disposed on the front and back surfaces of the PCB board. The reflector is disposed inside the PCB board and is spaced apart from the PCB board by a first preset distance. Parallel transmission lines are provided on the PCB board, and the four antenna devices are fed at the centrosymmetric positions of the four pairs of radiation arms through the parallel transmission lines provided on the PCB board. The present invention solves the technical problem of the contradiction between the high-precision requirements of amplitude comparison direction-finding in the field of anti-drones and the reduction of direction-finding efficiency and system integration degree brought about by the increase in the number of vibrators in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of passive anti - UAV direction finding and positioning, and particularly relates to an amplitude - comparison direction - finding antenna array and an anti - UAV passive direction - finding and positioning system. Background Art

[0002] As a key component of anti - UAV amplitude - comparison direction finding, the number of receiving array elements of the antenna array directly affects the direction - finding accuracy and efficiency of the anti - UAV system. Increasing the number of array elements can increase the selectivity of the system for the receiving direction of electromagnetic waves, thereby improving the direction - finding accuracy of the anti - UAV system. However, at the same time, it is necessary to increase the corresponding signal processing channels or radio - frequency switching switch channels, which will lead to an increase in hardware costs and integration difficulties, and the direction - finding scanning time will also increase linearly. Using a smaller number of antenna array elements to achieve more selectivity for the direction of electromagnetic waves can effectively improve the direction - finding accuracy and integration of the amplitude - comparison direction - finding system. Compared with the current amplitude - comparison direction - finding system with the same direction - finding resolution, better direction - finding efficiency can be achieved.

[0003] Figure 1 For the amplitude - comparison direction - finding antenna array commonly used at present, since the Yagi antenna has good direction selectivity, the amplitude - comparison direction finding often uses Yagi antennas to form a circular array to detect the direction of electromagnetic waves in the horizontal direction. The cross - sectional size of the Yagi antenna is relatively large, which will cause the antenna array using this scheme to be not easy to be integrated with the signal processing unit or the cross - sectional size after integration is relatively large; amplitude - comparison direction finding calculates the direction of electromagnetic waves through the correspondence between the intensity of the electromagnetic wave signals received by each antenna of the antenna array and the receiving antenna pattern. The number of receiving antenna units is inversely related to the size of the virtual angle of the direction - finding algorithm and positively related to the direction - finding accuracy. To improve the direction - finding accuracy, only the Figure 2 method of increasing the number of antenna array units can be adopted, but the hardware cost will also increase accordingly, and at the same time, the direction - finding efficiency is reduced. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above - mentioned technical deficiencies, and provide an amplitude - comparison direction - finding antenna array and an anti - UAV passive direction - finding and positioning system, so as to solve the technical problem of the contradiction between the high - precision requirements of amplitude - comparison direction finding in the anti - UAV field and the reduction of direction - finding efficiency and system integration degree caused by the increase in the number of vibration elements.

[0005] To achieve the above - mentioned technical purpose, the present invention adopts the following technical solutions:

[0006] In the first aspect, the present invention provides an amplitude - comparison direction - finding antenna array, including four antenna devices, and two adjacent antenna devices are arranged vertically to form an antenna array;

[0007] The antenna device includes a reflector, a PCB board, and radiation arm pairs disposed on the front and back surfaces of the PCB board. The reflector is disposed inside the PCB board and is spaced apart from the PCB board by a first preset distance. A parallel transmission line is provided on the PCB board, and the four antenna devices are fed at the centrally symmetric positions of the four radiation arm pairs through the parallel transmission line provided on the PCB board.

[0008] Preferably, in the amplitude comparison direction-finding antenna array, the first preset distance is 1 / 4 of the antenna wavelength.

[0009] Preferably, in the amplitude comparison direction-finding antenna array, the radiation arm pair includes four arm pairs, and each arm pair includes two arms distributed on the front and back surfaces of the PCB board. The four arms on the same surface of the PCB board are arranged in a 2×2 array, and the arms in the same row are spaced apart by a second preset distance.

[0010] Preferably, in the amplitude comparison direction-finding antenna array, the second preset distance is 1 / 4 of the antenna wavelength.

[0011] Preferably, in the amplitude comparison direction-finding antenna array, the antenna device further includes a plurality of impedance adjustment components corresponding to the arm pairs one by one. The impedance adjustment components are disposed at the intersections of the arm pairs and are electrically connected to the two arms of the arm pairs.

[0012] Preferably, in the amplitude comparison direction-finding antenna array, the impedance adjustment component includes a chip capacitor and a radio frequency switch. One end of the chip capacitor is electrically connected to the arm on the back surface of the PCB board through a metal via, the other end of the chip capacitor is connected to the path switching pin of the radio frequency switch, and the long-pass pin of the radio frequency switch is electrically connected to the arm on the front surface of the PCB board.

[0013] Preferably, in the amplitude comparison direction-finding antenna array, the chip capacitor is a 1.2 Pf chip capacitor.

[0014] Preferably, in the amplitude comparison direction-finding antenna array, the radio frequency switch is a single-channel radio frequency gating switch.

[0015] Preferably, in the amplitude comparison direction-finding antenna array, the radio frequency switch is controlled by the GPIO interface of the signal processing unit.

[0016] In a second aspect, the present invention further provides an unmanned aerial vehicle passive direction-finding and positioning system, including the amplitude comparison direction-finding antenna array as described above.

[0017] Compared with the prior art, the amplitude comparison direction-finding antenna array and the anti-drone passive direction-finding and positioning system provided by the present invention have a smaller cross-sectional size, more selectivity in the direction of the incoming wave, higher direction-finding efficiency, and can achieve a gain and beam width equivalent to those of a Yagi antenna by adopting a dipole plus reflector plate scheme with multiple radiation arms. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a layout schematic diagram of an amplitude comparison direction-finding antenna array in the prior art;

[0019] Figure 2 is a layout schematic diagram of another amplitude comparison direction-finding antenna array in the prior art;

[0020] Figure 3 is a layout schematic diagram of a preferred embodiment of the amplitude comparison direction-finding antenna array provided by the present invention;

[0021] Figure 4 is a schematic diagram of a preferred embodiment of the radiation arm pair in the amplitude comparison direction-finding antenna array provided by the present invention;

[0022] Figure 5a is a simulation data diagram of the receiving pattern of a single radiation unit in one state of the amplitude comparison direction-finding antenna array provided by the present invention;

[0023] Figure 5b is a simulation data diagram of the receiving pattern of a single radiation unit in another state of the amplitude comparison direction-finding antenna array provided by the present invention;

[0024] Figure 5c is a simulation data diagram of the receiving pattern of a single radiation unit in yet another state of the amplitude comparison direction-finding antenna array provided by the present invention;

[0025] Figure 6 is a layout schematic diagram of a preferred embodiment of a 2.4G & 5G dual-band amplitude comparison direction-finding antenna array provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0027] Please refer to Figure 3 , the amplitude comparison direction-finding antenna array provided by the embodiment of the present invention includes four antenna devices, and two adjacent antenna devices are arranged vertically to form an antenna array.

[0028] The antenna device includes a reflector, a PCB board, and radiation arm pairs disposed on the front and back surfaces of the PCB board. The reflector is disposed inside the PCB board and is spaced apart from the PCB board by a first preset distance. A parallel transmission line is provided on the PCB board, and the four antenna devices are fed at the centrally symmetric positions of the four radiation arm pairs through the parallel transmission lines provided on the PCB board.

[0029] The amplitude comparison direction-finding antenna array and the anti-drone passive direction-finding and positioning system provided in this embodiment have a smaller cross-sectional size, more selectivity for the incoming wave direction, and higher direction-finding efficiency. By adopting the dipole plus reflector scheme with multiple radiation arms, a gain and beam width equivalent to that of a Yagi antenna can be achieved.

[0030] Specifically, as Figure 3 shown, the antenna device composed of PCB board 1 and reflector 11, the antenna device composed of PCB board 2 and reflector 21, the antenna device composed of PCB board 3 and reflector 31, and the antenna device composed of PCB board 4 and reflector 41 are pairwise orthogonal. The radiation arms are distributed on the front and back surfaces of the PCB board and are fed through the parallel transmission lines 131 and 132 distributed on both sides of the PCB board. The feeding point 133 is located at the central position of the parallel transmission line.

[0031] In some embodiments, the PCB board is made of a metal plate or a fully copper-clad PCB board material, and a through-hole is opened in the center of the board to facilitate the passage of the feeding coaxial cable and connect it to the signal processing unit.

[0032] In some embodiments, the first preset distance is 1 / 4 of the antenna wavelength, that is, the reflector is spaced apart from the PCB board by λ / 4.

[0033] In some embodiments, the radiation arms can be arranged in various ways, such as a trapezoidal structure, a rhombus structure, an elliptical structure, etc. The embodiments of the present invention do not limit this.

[0034] Preferably, the radiation arm pair includes four arm pairs, and each arm pair includes two arms distributed on the front and back surfaces of the PCB board. The four arms located on the same surface of the PCB board are arranged in a 2×2 array, and the arms in the same row are spaced apart by a second preset distance.

[0035] Preferably, the second preset distance is 1 / 4 of the antenna wavelength.

[0036] Specifically, as Figure 3As shown, the receiving antenna consists of 4 pairs of λ / 4 arms 121, 122, 123, 124, 125, 126, 127, 128. The horizontal adjacent arms 121 and 123 (including 122 and 124, 125 and 127, 126 and 128) have a spacing of λ / 4. Each pair of arms 121 and 122 (including 123 and 124, 125 and 126, 127 and 128) are distributed on the front and back sides of the PCB and are fed through parallel transmission lines 131, 132 distributed on both sides of the PCB. The feeding point 133 is located at the center of the parallel transmission line.

[0037] In some embodiments, in order to adjust the electromagnetic wave reception pattern of a single antenna device, the antenna device further includes a number of impedance adjustment components corresponding one-to-one to the arm pairs. The impedance adjustment components are arranged at the intersections of the arm pairs and are electrically connected to the two arms of the arm pairs.

[0038] Preferably, the impedance adjustment component includes a chip capacitor and a radio frequency switch. One end of the chip capacitor is electrically connected to the arm on the back side of the PCB through a metal via. The other end of the chip capacitor is connected to the path switching pin of the radio frequency switch. The long pass pin of the radio frequency switch is electrically connected to the arm on the front side of the PCB.

[0039] Preferably, the chip capacitor is a 1.2Pf chip capacitor.

[0040] Preferably, the radio frequency switch is a single-channel radio frequency gating switch.

[0041] Preferably, the radio frequency switch is controlled by the GPIO interface of the signal processing unit.

[0042] Specifically, as Figure 3 and Figure 4 shown, in this embodiment, the impedance adjustment devices 12101, 12103, 12105, 12107 are all 1.2Pf chip capacitors, and 12102, 12104, 12106, 12108 are single-channel radio frequency gating switches. As Figure 3 shown, at the bifurcation of the receiving unit PCB arms 121 and 122, chip capacitor 12101 and radio frequency switch 12102 are arranged. Similarly, at the intersections of other arm pairs, chip capacitor 12103, radio frequency switch 1204, chip capacitor 12105, radio frequency switch 12106, chip capacitor 12107, and radio frequency switch 12108 are arranged. One ends of chip capacitors 12101, 12103, 12105, 12107 are connected to the bifurcations of the radiation arms on the back side of the PCB through metal vias, and the other ends are connected to the switch selection pins of radio frequency switches 12102, 12104, 12106, 12108. The normally open pins of the radio frequency switches are connected to the bifurcations of the other radiation arms on the front side of the PCB.

[0043] Furthermore, the vibrating arms 121 and 122, together with the chip capacitors 12101 and the RF switches 12102, form the receiving component 101; the vibrating arms 123 and 124, together with the chip capacitors 12103 and the RF switches 12104, form the receiving component 102; the vibrating arms 125 and 126, together with the chip capacitors 12105 and the RF switches 12106, form the receiving component 103; the vibrating arms 127 and 128, together with the chip capacitors 12107 and the RF switches 12108, form the receiving component 104; the receiving components 101 and 102 (103 and 104) are electromagnetic wave receiving direction regulators for each other.

[0044] In this embodiment, the 2.4G frequency band commonly used in civilian drones is selected to simulate the switching of the receiving direction pattern of the antenna unit. When the RF switches 12102, 12104, 12106, and 12108 in the components 101, 102, 103, and 104 are in the off state, the electromagnetic wave receiving direction pattern of the receiving unit is as shown in Figure 5a shown, and the maximum incoming wave gain direction is 90 degrees; when the RF switches 12102 and 12106 in the components 101 and 103 are respectively connected to the capacitors 12101 and 12105, and the RF switches 12104 and 12108 in the components 102 and 104 are in the off state, the electromagnetic wave receiving direction pattern of the receiving unit is as shown in Figure 5b shown, and the maximum incoming wave gain direction is 120 degrees; when the RF switches 12104 and 12108 in the components 102 and 104 are respectively connected to the capacitors 12103 and 12107, and the RF switches 12102 and 12106 in the components 101 and 103 are in the off state, the electromagnetic wave receiving direction pattern of the receiving unit is as shown in Figure 5c shown, and the maximum incoming wave gain direction is 60 degrees; similarly configuring the array units 2, 3, and 4, 12 incoming wave receiving direction pattern states of 0 degrees (360 degrees), 30 degrees, 60 degrees, 90 degrees, 120 degrees, 150 degrees, 180 degrees, 210 degrees, 240 degrees, 270 degrees, 300 degrees, and 330 degrees can be obtained on the horizontal plane. Obviously, by using more capacitors, inductors, and selecting more RF switch channels, more receiving direction patterns of the antenna unit can be switched.

[0045] In this embodiment, the antenna array uses four physical antenna receiving units to achieve 12 optional states of the incoming wave receiving pattern. Compared with the current conventional scheme, fewer array units are used to achieve more direction selectivity, improving the direction finding accuracy and system integration. The incoming wave direction scanning scheme of this embodiment can be divided into two steps: rough scanning and refined scanning. First, disconnect the impedance adjustment device of the antenna unit, and use four physical antenna units (corresponding to the maximum gain directions of incoming waves at 0 degrees, 90 degrees, 180 degrees, and 270 degrees) to quickly scan the direction of the target signal electromagnetic wave. After roughly measuring the angle between the incoming direction of the electromagnetic wave and the maximum gain direction of the physical antenna element, the impedance of the virtual components of the two physical antenna units adjacent to the incoming wave direction is adjusted through the GPIO control signal of the signal processing unit, so that the antenna array has more receiving direction selectivity in the incoming wave direction, achieving a balance between the direction finding resolution and direction finding efficiency of the system.

[0046] In addition Figure 6 A layout scheme of the antenna array for a dual-frequency direction finding system is provided. Similarly, on each direction finding frequency band, fewer antenna element numbers can be used to achieve more selectivity of the incoming electromagnetic wave directions.

[0047] Based on the above amplitude comparison direction finding antenna array, an embodiment of the present invention further provides a passive direction finding and positioning system for an unmanned aerial vehicle, including the amplitude comparison direction finding antenna array as described in the above embodiments. Since the amplitude comparison direction finding antenna array has been described in detail above, it will not be elaborated here.

[0048] In summary, the amplitude comparison direction finding antenna array and the anti-unmanned aerial vehicle passive direction finding and positioning system provided by the present invention have a smaller cross-sectional size, more selectivity of the incoming wave directions, higher direction finding efficiency. By adopting the scheme of a dipole with multiple radiation arms plus a reflector, a gain and beam width equivalent to that of a Yagi antenna can be achieved. Patch capacitors and RF switches are used to adjust the impedance of horizontally adjacent radiation sections to realize the switching of the radiation unit pattern; one receiving unit can achieve more than three incoming wave direction selectivities with the cooperation of the GPIO control signal.

[0049] The specific embodiments of the present invention described above do not constitute a limitation to the protection scope of the present invention. Any other corresponding changes and deformations made according to the technical concept of the present invention should be included within the protection scope of the claims of the present invention.

Claims

1. A comparison amplitude direction-finding antenna array, characterized in that It includes four antenna devices, with two adjacent antenna devices arranged vertically to form an antenna array; The antenna device includes a reflector, a PCB board, and a pair of radiation arms disposed on the front and back surfaces of the PCB board. The reflector is disposed inside the PCB board and is spaced from the PCB board by a first preset distance. Parallel transmission lines are provided on the PCB board, and the four antenna devices are fed at the centrosymmetric positions of the four pairs of radiation arms through the parallel transmission lines provided on the PCB board; The pair of radiation arms includes four pairs of vibrating arms. Each pair of vibrating arms includes two vibrating arms distributed on the front and back surfaces of the PCB board. The four vibrating arms on the same surface of the PCB board are arranged in a 2×2 array, and the vibrating arms in the same row are spaced apart by a second preset distance; The antenna device further includes a plurality of impedance adjustment components corresponding to the pairs of vibrating arms one by one. The impedance adjustment components are disposed at the intersections of the pairs of vibrating arms and are electrically connected to the two vibrating arms of the pair of vibrating arms; The impedance adjustment component includes a chip capacitor and a radio frequency switch. One end of the chip capacitor is electrically connected to the vibrating arm on the back surface of the PCB board through a metal via, the other end of the chip capacitor is connected to the path switching pin of the radio frequency switch, and the long-pass pin of the radio frequency switch is electrically connected to the vibrating arm on the front surface of the PCB board.

2. The amplitude comparison direction-finding antenna array according to claim 1, characterized in that, The first preset distance is 1 / 4 of the antenna wavelength.

3. The amplitude comparison direction-finding antenna array according to claim 2, characterized in that, The second preset distance is 1 / 4 of the antenna wavelength.

4. The amplitude comparison direction finding antenna array according to claim 3, characterized in that, The chip capacitor is a 1.2Pf chip capacitor.

5. The amplitude comparison direction finding antenna array according to claim 3, characterized in that, The radio frequency switch is a single-channel radio frequency gating switch.

6. The amplitude comparison direction-finding antenna array according to claim 3, wherein The radio frequency switch is controlled by the GPIO interface of the signal processing unit.

7. A passive direction-finding and positioning system for an unmanned aerial vehicle, characterized in that, It includes the amplitude comparison direction-finding antenna array according to any one of claims 1-6.

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