A compass anti-interference antenna array

Abstract

The application discloses a Beidou anti-interference antenna array, which comprises an antenna array, a decoupling super surface and a radome; the decoupling super surface is located between the antenna array and the radome; the antenna array comprises a plurality of antenna array elements; the plurality of antenna array elements are arranged on a whole PCB board to form the antenna array; the decoupling super surface comprises a plurality of periodically arranged basic structure units; each basic structure unit is a bent line ring-shaped printed circuit; the basic structure unit is equivalent to an inductance L; the gap between two basic structure units is equivalent to a capacitance C; the LC resonance can block the propagation of electromagnetic waves in the plane direction, that is, the mutual coupling transmission path is blocked. Through the design of the decoupling super surface, the mutual coupling of the miniaturized Beidou anti-interference antenna array is reduced, and the isolation between the Beidou anti-interference antenna array elements is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of satellite navigation system, and relates to a Beidou anti-interference antenna array. BACKGROUND

[0002] As a global satellite navigation system independently developed by China, the Beidou satellite navigation system has a wide range of applications in surveying and mapping, water conservancy, fisheries, transportation and military fields. However, because the navigation satellite is far from the earth, the satellite signal is very weak, and therefore it is very easy to be disturbed by complex environment or human factors. Such interference may cause distortion of the navigation signal, decrease in accuracy or even complete loss, which has a serious impact on applications relying on Beidou navigation. To cope with interference, anti-interference antenna arrays are widely used in Beidou anti-interference systems. However, with the miniaturization and densification of the antenna array, the mutual coupling problem between the antenna elements is increasingly prominent, and the mutual coupling not only reduces the performance of the antenna but also affects the signal-to-noise ratio of the system, thereby affecting the performance of the entire system. SUMMARY

[0003] The purpose of the present application is to provide a Beidou anti-interference antenna array, which improves system performance, enhances anti-interference ability and promotes miniaturization of the antenna array through the composite integrated design of the decoupling metasurface, thereby expanding the application scenarios.

[0004] To solve the above technical problems, the technical scheme of the present application is as follows:

[0005] A Beidou anti-interference antenna array, comprising an antenna array, a decoupling metasurface and a radome.

[0006] The decoupling metasurface is located between the antenna array and the radome, the antenna array comprises a plurality of antenna elements, the plurality of antenna elements are arranged and printed on a whole PCB board to form the antenna array, the decoupling metasurface comprises a plurality of periodically arranged basic structure units, each basic structure unit is a meander line ring-shaped printed circuit, the basic structure unit has an equivalent inductance L, and the gap between two basic structure units has an equivalent capacitance C, which can realize LC resonance to block the propagation of electromagnetic waves in the XY plane direction, i.e. to block the mutual coupling transmission path.

[0007] Further, the decoupling metasurface is printed on a single-sided PCB.

[0008] Further, the radome and the decoupling metasurface are composite integrated, and the printed circuit of the decoupling metasurface is covered in a dielectric.

[0009] Further, each edge of the meander line ring-shaped printed circuit is a quarter of the dielectric wavelength.

[0010] Further, the antenna array element comprises a dielectric substrate, a radiation patch and a coaxial feeding probe, the dielectric substrate is printed with copper foil on the bottom layer, and the radiation patch is on the upper layer of the dielectric substrate, and the antenna array element converts the free space wave into a guided wave by receiving the right-handed circularly polarized wave through the coaxial feeding probe.

[0011] Further, the antenna array element adopts a cut-angle single-feed microstrip antenna design, and realizes the right-handed circular polarization characteristic of the array element through cut-angle perturbation.

[0012] Further, the number of the antenna array elements is four, and the four antenna array elements are rotationally arranged on a whole PCB board.

[0013] Compared with the prior art, the technical effects achieved by the application are as follows:

[0014] Through the composite integrated design of the decoupling super surface, the performance of the Beidou anti-interference antenna array system is improved, the anti-interference ability is enhanced, the antenna array is miniaturized, and the application scene of the Beidou anti-interference antenna array is expanded.

[0015] 1. The decoupling super surface design reduces the mutual coupling of the miniaturized Beidou anti-interference antenna array, and realizes the improvement of the isolation degree between the Beidou anti-interference antenna array elements.

[0016] 2. The decoupling super surface adopts a meander line type ring periodic structure design, and the period structure size is further reduced through the meander line design.

[0017] 3. The anti-interference performance of the Beidou anti-interference antenna array is greatly improved under the same size of the antenna array.

[0018] 4. The antenna array element adopts a single-feed perturbation feeding mode to realize right-handed circular polarization, and the antenna array adopts a rotation arrangement. BRIEF DESCRIPTION OF DRAWINGS

[0019] ATTACHMENT Figure 1 It is a schematic view of the three-dimensional structure of the Beidou anti-interference antenna array;

[0020] ATTACHMENT Figure 2 It is a side view of the Beidou anti-interference antenna array;

[0021] ATTACHMENT Figure 3 It is an exploded view of the Beidou anti-interference antenna array;

[0022] ATTACHMENT Figure 4 It is a schematic view of the decoupling super surface;

[0023] ATTACHMENT Figure 5 It is a schematic view of the basic structure unit of the decoupling super surface;

[0024] ATTACHMENT Figure 6 It is a schematic view of the four-element antenna array;

[0025] ATTACHMENTFigure 7 This is the main view of the antenna array elements;

[0026] Appendix Figure 8 This is a side view of an antenna array element.

[0027] Appendix Figure 9 A typical isolation variation diagram before and after adding the decoupling metasurface;

[0028] Appendix Figure 10 Comparison of unit radiation patterns before and after adding the decoupled metasurface;

[0029] Appendix Figure 11 Comparison of anti-interference null traps for antenna arrays at typical azimuth 0° and elevation 10° before and after adding a decoupling metasurface. Detailed Implementation

[0030] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0031] like Figures 1-5 As shown, a BeiDou anti-interference antenna array includes an antenna array, a decoupling metasurface, and an antenna radome.

[0032] The decoupling metasurface is located between the antenna array and the radome. The antenna array includes four antenna elements, which are rotated and printed on a single PCB board to form the antenna array (e.g., Figure 6 (as shown); the decoupling metasurface comprises multiple periodically arranged basic structural units (such as...) Figure 5 As shown, each basic structural unit is a zigzag-line ring-shaped printed circuit. The zigzag design transforms straight lines into zigzag lines, reducing the planar size occupied by lines of equal physical length. This facilitates the miniaturization of the antenna array below and further reduces the size of the periodic structure. Each side of the zigzag-line ring-shaped printed circuit is approximately one-quarter of the dielectric wavelength. The equivalent inductance L of the basic structural unit in the XY plane and the equivalent capacitance C of the gap between two basic structural units enable LC resonance to block the propagation of electromagnetic waves in the planar direction, i.e., blocking the mutual coupling transmission path without affecting the normal operation of the antenna. The decoupling metasurface is located above the antenna array and integrated with the radome. The decoupling metasurface uses conventional FR4 material with a dielectric constant of approximately 4.2 as the dielectric substrate and is printed on the upper layer of the dielectric substrate. This reduces the mutual coupling of the miniaturized BeiDou anti-interference antenna array and improves the isolation between the elements of the BeiDou anti-interference antenna array.

[0033] Preferably, the decoupling metasurface is printed on a single-sided PCB.

[0034] Preferably, the radome is complexly integrated with the decoupling metasurface, the printed circuit of the decoupling metasurface is wrapped in a medium to improve the environmental adaptability (corrosion resistance) of the metasurface, the radome is located at the outermost side of the antenna array and plays a role of isolation from the outside, thereby improving the environmental adaptability of the antenna system, and a conventional radome material (such as glass steel) is adopted.

[0035] Preferably, in combination with Figures 6-8 , the antenna array element comprises a dielectric substrate, a radiation patch, and a coaxial feeding probe, the bottom layer of the dielectric substrate is a printed copper sheet to play a role of floor directional reception, the upper layer of the dielectric substrate is a radiation patch, and the antenna array element converts a free space wave into a guided wave by receiving a right-handed circularly polarized wave through the coaxial feeding probe.

[0036] Preferably, the antenna array element adopts a conventional cut-angle single-feed microstrip antenna design, the right-handed circular polarization characteristic of the array element is realized through cut-angle perturbation, and a Rogers RO3210 board material with a relative dielectric constant of about 10.2 is adopted. Four antenna array elements are rotationally arranged and printed on a whole PCB board, this scheme is simple and basically not affected by assembly process, has stable performance and high product consistency. The external feeding interface of the antenna array element adopts a standard 50Ω coaxial line / joint.

[0037] Figure 9 Typical isolation degree changes S21, S31, and S41 before and after adding the decoupling metasurface are shown, the left graph is without the decoupling metasurface, and the right graph is with the decoupling metasurface.

[0038] Figure 10 Element pattern comparison before and after adding the decoupling metasurface is shown, the red line is without the decoupling metasurface, and the blue line is with the decoupling metasurface, which improves the element pattern distortion caused by the mutual coupling of the miniaturized Beidou anti-interference antenna array element.

[0039] Figure 11 Typical angle azimuth 0 and elevation 10° antenna array anti-interference null comparison before and after adding the decoupling metasurface is shown, the red color is without the decoupling metasurface, and the blue color is with the decoupling metasurface, which can greatly improve the anti-interference performance of the Beidou anti-interference antenna array under the same size of the antenna array.

[0040] From the above simulation Figures 9-11 It can be calculated that:

[0041] 1. Taking the Beidou B3 center frequency point as an example, the element mutual coupling is obviously reduced, and the isolation degree is improved by more than 10 dB.

[0042] 2. Taking the Beidou B3 center frequency point as an example, the element pattern distortion caused by the mutual coupling of the miniaturized Beidou anti-interference antenna array element is obviously improved.

[0043] 3. Taking the center frequency of Beidou B3 as an example, the null is improved by more than 4dB under the ideal anti-interference amplitude and phase condition after adding the decoupling metasurface.

[0044] 4. Combined with the improvement of isolation between channels (signal-to-noise ratio improvement), this decoupling metasurface design will greatly improve the anti-interference performance of the Beidou anti-interference antenna array.

[0045] The above shows and describes the basic principles, main features and advantages of the present application. It should be understood by those skilled in the art that the present application is not limited to the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A BeiDou anti-jamming antenna array, characterized in that, The antenna array, the decoupling metasurface, and the radome are provided. The decoupling metasurface is located between the antenna array and the radome, the antenna array comprises a plurality of antenna elements, the plurality of antenna elements are arranged on a whole PCB board to form the antenna array, the decoupling metasurface comprises a plurality of periodically arranged basic structure units, each basic structure unit is a bent line ring-shaped printed circuit, the bent length of the bent line on each side decreases from the center to both sides, and the bent lines on the four sides form a closed ring as a whole, the basic structure unit has an equivalent inductance L, and the gap between two basic structure units has an equivalent capacitance C, so that LC resonance can be achieved to block the propagation of electromagnetic waves in the plane direction, i.e., to block the mutual coupling transmission path. Each side of the bent line ring-shaped printed circuit is a quarter of the dielectric wavelength. The antenna element comprises a dielectric substrate, a radiation patch, and a coaxial feeding probe, the bottom layer of the dielectric substrate is a printed copper sheet, the upper layer of the dielectric substrate is the radiation patch, and the antenna element receives right-handed circularly polarized waves through the coaxial feeding probe to convert the free space wave into a guided wave.

2. The anti-jamming Beidou antenna array of claim 1, wherein, The decoupling metasurface is printed on a single-sided PCB.

3. The anti-jamming Beidou antenna array of claim 1, wherein, The radome and the decoupling metasurface are complexly integrated, and the printed circuit of the decoupling metasurface is covered in the dielectric.

4. The anti-jamming Beidou antenna array of claim 1, wherein, The antenna element adopts a cut-angle single-feed microstrip antenna design, and the right-handed circular polarization characteristic of the antenna element is realized through cut-angle perturbation.

5. The anti-jamming Beidou antenna array of claim 4, wherein, The number of the antenna elements is four, and the four antenna elements are rotationally arranged on a whole PCB board.

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