Miniaturized device of high-precision unmanned aerial vehicle image transmission signal direction finding system

Abstract

The invention discloses a miniaturized device of a high-precision unmanned aerial vehicle image transmission signal direction finding system. The miniaturized device comprises a detection direction finding antenna and a host, the detection direction-finding antenna comprises a low-frequency-band antenna unit, a high-frequency-band antenna unit, an antenna switching matrix, a radio frequency module and an electric compass; the low-frequency-band antenna unit and the high-frequency-band antenna unit are respectively connected with the antenna switching matrix, and the antenna switching matrix is connected with the radio frequency module; the host comprises a power supply module, an intermediate frequency acquisition board card and an embedded computer module; the intermediate frequency acquisition board card is connected with the embedded computer module and the power supply module; the detection direction-finding antenna is connected with the host through a control cable and an intermediate frequency cable. The direction-finding array adopts a directional antenna unit, so that the physical size of an antenna is smaller than an equivalent direction-finding aperture. Therefore, the constraint of the antenna aperture on the minimum size of equipment is broken, and the purpose of miniaturization is achieved.

Description

Technical Field

[0001] The present invention relates to the field of radio monitoring technology, and in particular to a miniaturized device for a high-precision unmanned aerial vehicle (UAV) image transmission signal direction finding system. Background Art

[0002] With the rapid development of drone technology, important units such as airports, nuclear power plants, oil depots, and the military have continuously received reports of drone intrusions, posing a threat to public safety. It has become a top priority to control illegal drones. The premise of drone control is to be able to detect drones and obtain their position. An effective technical route to obtain drone position information is to perform signal direction finding based on the radio signal array direction finding method. The higher the accuracy of detection and direction finding, the higher the success rate of subsequent drone deception and link interference suppression.

[0003] However, the traditional direction-finding system can only guarantee a high direction-finding accuracy when the aperture is large enough and the antenna segmentation is sufficient. As a result, the traditional direction-finding equipment is large in size, poor in concealment, and difficult to carry. The operating frequency of the common drone image transmission signal almost covers the frequency band from 500MHz to 6000MHz. In order for the equipment to be able to perform direction finding on the entire frequency band, the system has large differences in the aperture requirements of the low-end and high-end direction-finding arrays, and the direction-finding antenna array needs to be designed in layers. At the same time, the requirements for drone prevention and control work are high mobility, high concealment, and high portability. Therefore, it is urgent to resolve the contradiction between high-precision requirements and equipment miniaturization. Summary of the invention

[0004] The purpose of the present invention is to provide a miniaturized device for a high-precision UAV image transmission signal direction finding system, in order to solve the technical problems in the background technology.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A miniaturized device for a high-precision UAV image transmission signal direction finding system, comprising:

[0007] Detect direction-finding antenna and host;

[0008] The detection and direction-finding antenna comprises a low-frequency antenna unit, a high-frequency antenna unit, an antenna switching matrix, a radio frequency module, and an electric compass; the low-frequency antenna unit and the high-frequency antenna unit are respectively connected to the antenna switching matrix, and the antenna switching matrix is ​​connected to the radio frequency module;

[0009] The host comprises a power module, an intermediate frequency acquisition board, and an embedded computer module; the intermediate frequency acquisition board is connected to the embedded computer module and the power module;

[0010] The detection and direction-finding antenna is connected to the host through a control cable and an intermediate frequency cable.

[0011] In some embodiments, the low-frequency band antenna unit and the high-frequency band antenna unit are directional antenna units.

[0012] In some embodiments, the structural cavity of the detection and direction-finding antenna serves as a reflector of the antenna unit; the antenna switching matrix, the radio frequency module, and the electric compass are integrated in the structural cavity of the detection and direction-finding antenna.

[0013] In some embodiments, the operating frequency band range of the low-frequency band antenna unit is 500 MHz-2400 MHz, and the operating frequency band range of the high-frequency band antenna unit is 2400 MHz-6000 MHz.

[0014] In some embodiments, the normal directions of the low-frequency band antenna unit and the high-frequency band antenna unit of the detection and direction finding antenna are tilted.

[0015] In some embodiments, the detection and direction-finding antenna has 8 antenna elements, which are divided into two layers of antennas.

[0016] In some embodiments, the angle between the reflection surface of the low-frequency band antenna unit and the high-frequency band antenna unit of the detection and direction-finding antenna and the horizontal plane is 60°.

[0017] The present invention has the following beneficial effects:

[0018] (1) The direction-finding array uses directional antenna units, which makes the physical size of the antenna smaller than the equivalent direction-finding aperture.

[0019] This breaks the constraint of the antenna aperture on the minimum size of the device and achieves the goal of miniaturization;

[0020] (2) The antenna structure cavity is used as a reflector for the antenna unit, which simplifies the design and further reduces the size;

[0021] (3) The amplitude and phase vector direction finding method is applied to achieve a direction finding accuracy comparable to that of a conventional omnidirectional antenna array;

[0022] (4) The normal direction of the direction-finding antenna is tilted, which reduces the height of the entire device while keeping the spacing between the high and low end antenna units unchanged;

[0023] (5) The inner cavity space of the antenna array reflective surface is fully utilized to integrate the RF front-end module into it, which reduces the size of the host and also reduces the sensitivity deterioration problem caused by cable loss in the high frequency band. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is the electrical principle block diagram of the present invention;

[0025] Figure 2 This is a layout diagram of the detection and direction-finding antenna composition according to an embodiment of the present invention.

[0026] Reference numerals:

[0027] 1- detection and direction finding antenna, 2- host, 3- low frequency band antenna unit, 4- high frequency band antenna unit, 5- electric compass, 6- antenna switching matrix, 7- radio frequency module, 8- intermediate frequency acquisition board, 9- embedded computer, 10- power supply module, 11- high frequency band antenna unit, 12- low frequency band antenna unit. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below in conjunction with the drawings in the preferred embodiments of the present application. In the drawings, the same or similar reference numerals throughout represent the same or similar parts or parts with the same or similar functions. The described embodiments are part of the embodiments of the present application, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limitations on the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0029] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0030] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0031] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are orientations or positional relationships based on 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 referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0032] In addition, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product, or display that includes a series of steps or elements is not necessarily limited to those steps or elements explicitly listed but may include other steps or elements not explicitly listed or inherent to such process, method, product, or display.

[0033] The following will be combined Figure 1-2 , a miniaturized device of a high-precision UAV image transmission signal direction finding system involved in the embodiment of the present application is described in detail. It is worth noting that the following embodiments are only used to explain the present application and do not constitute a limitation of the present application.

[0034] Embodiment 1:

[0035] like Figure 1 to Figure 2 As shown, a miniaturized device of a high-precision UAV image transmission signal direction finding system comprises:

[0036] Detection direction-finding antenna 1 and host 2; the detection direction-finding antenna 1 includes a low-frequency band antenna unit 123, a high-frequency band antenna unit 114, an antenna switching matrix 6, a radio frequency module 7, and an electric compass 5; the low-frequency band antenna unit 123 and the high-frequency band antenna unit 114 are respectively connected to the antenna switching matrix 6, and the antenna switching matrix 6 is connected to the radio frequency module 7;

[0037] The host 2 includes a power module 10, an intermediate frequency acquisition board 8, and an embedded computer 9 module; the intermediate frequency acquisition board 8 is connected to the embedded computer 9 module and the power module 10; the detection and direction finding antenna 1 is connected to the host 2 via a control cable and an intermediate frequency cable.

[0038] The working range of this embodiment is required to be 360° in the horizontal azimuth plane and 0-90° in the vertical elevation plane. The direction finding accuracy is required to be ≤3°RMS.

[0039] The low frequency band antenna unit 123 and the high frequency band antenna unit 114 are directional antenna units. The structural cavity of the detection and direction finding antenna 1 serves as a reflector of the antenna unit; the antenna switching matrix 6, the radio frequency module 7, and the electric compass 5 are integrated in the structural cavity of the detection and direction finding antenna 1.

[0040] In this embodiment, the number of antenna array elements is 8, which are divided into two layers of antennas, wherein the low-band working frequency range is 500MHz-2400MHz, and the high-band working frequency range is 2400MHz-6000MHz. The angle between the antenna reflection surface and the horizontal plane is not 60°, and the maximum diameter of the antenna is 41cm. The number of RF receiving channels and intermediate frequency processing channels is three. The host 2 adopts the plug-in module method to facilitate rapid integration with more complex systems. The instantaneous analysis bandwidth of the device is 80MHz.

[0041] The following is a comparison with a conventional direction-finding scheme that does not use the present invention. According to engineering implementation experience, in a conventional design, the antenna array is divided into at least two layers, and the number of antenna elements in each layer is not less than 7. The antenna segmentation is approximately around 2500MHz, and the antenna array aperture is not less than 50cm. Considering the size of the antenna itself, the actual antenna diameter is not less than 52cm. In order to ensure that the equiphase plane of the antenna unit is close to an ideal circle, avoid arranging other modules between the antenna units.

[0042] Under the same precision requirement, the present invention reduces the diameter of the device by about 11 cm, or about 21%.

[0043] Under the same precision requirement, if a conventional design is adopted, the isophase plane of the antenna unit must be close to the ideal circle, and the antenna switching matrix 6 and the radio frequency module 7 in the center of the antenna array must be moved down to avoid the increase of the antenna height by 5 cm, while the present invention reduces the height by about 20%.

[0044] In some embodiments, the focus is on monitoring areas with a high risk of drone intrusion, such as the area around an airport. In the airport airspace protection zone, the illegal intrusion of drones may seriously threaten the take-off and landing safety of civil aircraft, so there is an urgent need for fast and accurate direction finding of drone image transmission signals.

[0045] In terms of system hardware connection, the low-frequency band antenna unit 123 and the high-frequency band detection and direction-finding antenna 1 unit in the detection and direction-finding antenna 1 accurately capture the image transmission signal emitted by the drone according to their respective frequency band characteristics. The antenna switching matrix 6 quickly switches to the corresponding antenna unit according to the signal frequency band to ensure efficient reception of the signal. The RF module 7 performs necessary pre-processing such as filtering and amplification on the received signal, and converts the analog signal into a form suitable for subsequent processing. The electric compass 5 obtains the azimuth information of the detection and direction-finding antenna 1 in real time, providing basic data for direction-finding calculations. In the host 2 part, the power module 10 stably supplies power to each component to ensure the normal operation of the system. The intermediate frequency acquisition board 8 receives the signal from the RF module 7, performs intermediate frequency sampling and digital processing, and transmits the digital signal to the embedded computer 9 module.

[0046] In the system workflow, when the drone enters the monitoring area and transmits the image transmission signal, the detection and direction-finding antenna 1 receives the signal. Assuming that the frequency band of the drone image transmission signal is 3000MHz, the antenna switching matrix 6 directs the signal to the high-frequency detection and direction-finding antenna 1 unit. After the RF module 7 processes the signal, it is transmitted to the intermediate frequency acquisition board 8. The board completes the digital processing and transmits the data to the embedded computer 9 module. The module uses the amplitude and phase vector direction-finding method, combined with the antenna azimuth information provided by the electric compass 5, to calculate the drone's position. If it is calculated that the drone is located 10° in front of the airport runway, the system immediately issues an alarm to remind security personnel to take measures.

[0047] Compared with the traditional direction-finding scheme, in order to meet the high-precision direction-finding requirements in the airport environment, the antenna array usually needs to adopt a larger aperture and more array elements. The antenna diameter may be more than 60cm, and the height will be higher. In addition, due to the complex antenna layout and the difficulty of signal processing, the direction-finding accuracy is susceptible to interference. This embodiment adopts a directional antenna unit and a unique layout, with an antenna diameter of only 41cm and a significantly reduced height. In terms of direction-finding accuracy, the direction-finding accuracy of the traditional solution in a complex electromagnetic environment may fluctuate to more than 5°RMS, while the direction-finding accuracy of the technical solution of this embodiment is stabilized at ≤3°RMS, which greatly improves the monitoring capability of drones and effectively ensures the safety of the airport area.

[0048] The above description is only a preferred embodiment of the present invention and is used to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A miniaturized device for a high-precision UAV image transmission signal direction finding system, characterized in that: include: Detect direction-finding antenna and host; The detection and direction-finding antenna comprises a low-frequency antenna unit, a high-frequency antenna unit, an antenna switching matrix, a radio frequency module, and an electric compass; the low-frequency antenna unit and the high-frequency antenna unit are respectively connected to the antenna switching matrix, and the antenna switching matrix is ​​connected to the radio frequency module; The host comprises a power module, an intermediate frequency acquisition board, and an embedded computer module; the intermediate frequency acquisition board is connected to the embedded computer module and the power module; The detection and direction-finding antenna is connected to the host through a control cable and an intermediate frequency cable.

2. According to the miniaturized device of the high-precision UAV image transmission signal direction finding system of claim 1, it is characterized in that: The low-frequency band antenna unit and the high-frequency band antenna unit are directional antenna units.

3. The miniaturized device of the high-precision UAV image transmission signal direction finding system according to claim 1 is characterized in that: The structural cavity of the detection and direction-finding antenna serves as a reflector of the antenna unit; the antenna switching matrix, the radio frequency module, and the electric compass are integrated in the structural cavity of the detection and direction-finding antenna.

4. The miniaturized device of the high-precision UAV image transmission signal direction finding system according to claim 1 is characterized in that: The operating frequency range of the low-frequency band antenna unit is 500MHz-2400MHz, and the operating frequency range of the high-frequency band antenna unit is 2400MHz-6000MHz.

5. The miniaturized device of the high-precision UAV image transmission signal direction finding system according to claim 1 is characterized in that: The normal directions of the low-frequency band antenna unit and the high-frequency band antenna unit of the detection and direction finding antenna are inclined.

6. The miniaturized device of the high-precision UAV image transmission signal direction finding system according to claim 1 is characterized in that: The detection and direction finding antenna has 8 antenna array elements, which are divided into two layers of antennas.

7. The miniaturized device of the high-precision UAV image transmission signal direction finding system according to claim 1 is characterized in that: The angle between the reflection surface of the low-frequency band antenna unit and the high-frequency band antenna unit of the detection and direction-finding antenna and the horizontal plane is 60°.

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