GNSS antenna fence device

Abstract

The utility model discloses a GNSS (Global Navigation Satellite System) antenna fence device, which overcomes the problems in the prior art that the size and the cost are greatly increased while the gain of a GNSS antenna is improved, and the GNSS antenna fence device cannot be used in a narrow environment and a low-cost project, and comprises a bottom plate and a metal fence arranged on the bottom plate, one end of each metal branch knot is connected with the bottom plate, the other end of each metal branch knot is in an open-circuit high-resistance state, the metal branch knots are parallel to each other and are separated by air gaps, and a GNSS antenna device is mounted on the bottom plate. Electromagnetic field distribution of the antenna is optimized through the metal fence, sidelobe and back lobe signals and cross polarization components are suppressed, the structure is simple, and gain is improved while miniaturization design is kept.

Description

Technical Field

[0001] This utility model relates to the field of satellite navigation and positioning technology, and in particular to a GNSS antenna fence device. Background Technology

[0002] With the rapid development of Global Navigation Satellite Systems (GNSS), multiple systems such as GPS, GLONASS, GALILEO, and BeiDou Navigation Satellite System coexist, and multi-mode fusion is accelerating. The reliability, stability, and positioning accuracy of using a single satellite navigation system are difficult to guarantee. A satellite navigation system that integrates multiple systems can achieve better positioning performance than using any single system alone. In satellite navigation and positioning technology, the antenna, as a key component for receiving satellite signals, is crucial to the quality and accuracy of satellite signal reception.

[0003] In current navigation antenna technology, several methods exist to achieve high antenna gain: increasing the size and thickness of the product can improve antenna gain and bandwidth; increasing the size of the backplate used in the antenna can also improve gain and bandwidth; and using new air dielectrics and new composite structures. However, all of these methods significantly increase the size and structure of the antenna, resulting in a substantial increase in cost, making it difficult to meet the needs of some confined environments and low-cost projects. For example, the patent CN117317590B published by the Chinese Patent Office on December 29, 2023, describes a GNSS antenna with a new structural design. The filling medium enhances the ability to confine electromagnetic waves, optimizes low elevation angle gain, and widens the beamwidth. However, it also suffers from the problems of complex GNSS antenna structure and high cost. Summary of the Invention

[0004] The purpose of this invention is to overcome the problem that while improving the antenna gain of GNSS antennas in the prior art, the size and cost increase significantly, making them unsuitable for use in confined environments and low-cost projects. This invention provides a GNSS antenna enclosure device that optimizes the electromagnetic field distribution of the antenna through a metal enclosure, suppresses sidelobe and backlobe signals as well as cross-polarization components, has a simple structure, and improves gain while maintaining a miniaturized design.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A GNSS antenna fence device includes a base plate and a metal fence mounted on the base plate. The metal fence includes inclined metal branches that are parallel to each other. One end of each metal branch is connected to the base plate, and the other end of each metal branch is in an open-circuit high-resistance state. The metal branches are separated by air gaps. A GNSS antenna device is mounted on the base plate.

[0007] The GNSS antenna enclosure device provided by this utility model optimizes the electromagnetic field distribution of the GNSS ceramic antenna by adding an enclosure structure around the GNSS ceramic antenna, suppressing sidelobe and backlobe signals as well as cross-polarization components. By optimizing the four-sided enclosure structure, the energy recovery in the non-main lobe direction of the GNSS ceramic antenna is improved, thereby increasing the antenna gain. Moreover, the volume of the metal enclosure only increases the total size of the antenna by 5% to 15%, but the effective antenna gain can be improved by 1 to 3 dB, and the bandwidth can be increased by more than 30 to 50%.

[0008] Preferably, the metal fence has a polygonal structure, and the metal branches in the metal fence are inclined in a clockwise or counterclockwise direction.

[0009] Preferably, the metal fence has a circular structure, and the metal branches in the metal fence are inclined in a clockwise or counterclockwise direction.

[0010] Preferably, the metal fence includes a support post, and the metal branch includes a first branch and a second branch. One end of the first branch is in an open-circuit high-resistance state, and the other end of the first branch is integrally connected to the support post. One end of the second branch is connected to the base plate, and the other end of the second branch is in an open-circuit high-resistance state.

[0011] Preferably, the air gap between the metal branches is less than 1 / 10 of the air wavelength.

[0012] Preferably, the tilt angle of the metal branch is 0-90 degrees.

[0013] Preferably, the first branch and the second branch are parallel, the first branches are parallel to each other, the second branches are parallel to each other, and the air gap between the first branch and the second branch is equal to the air gap between the first branch and the second branch.

[0014] Preferably, the GNSS antenna device includes a GNSS ceramic antenna and a PCB board, with the base plate installed between the GNSS ceramic antenna and the PCB board, and the GNSS ceramic antenna installed in a cavity formed by the base plate and a metal fence.

[0015] Preferably, the base plate has an antenna feed pin clearance hole at its center, and the base plate has a fence fixing foot, and the metal fence is connected to the base plate through the fence fixing foot.

[0016] Antenna feed pin clearance holes are used to prevent the connection between the antenna signal and the PCB board. The GNSS ceramic antenna is equipped with feed pin pins for transmitting antenna signals. These feed pin pins pass through the antenna feed pin clearance holes in the middle of the metal base plate and connect to the PCB board at the bottom of the base plate. The metal fence is connected to the base plate via fence fixing feet.

[0017] Preferably, the GNSS antenna device includes a GNSS ceramic antenna and a PCB board, which are installed in a cavity formed by a base plate and a metal fence.

[0018] Therefore, this invention has the following beneficial effects: by adding a metal fence around the GNSS ceramic antenna, the electromagnetic field distribution of the GNSS ceramic antenna is optimized, sidelobe and backlobe signals and cross-polarization components are suppressed, and the antenna gain is improved by optimizing the fence structure to recover energy in the non-main lobe direction of the GNSS ceramic antenna. Moreover, the fence volume only increases the total size of the antenna by 5% to 15%, but the effective gain of the GNSS ceramic antenna can be improved by 1 to 3 dB and the bandwidth can be increased by more than 30 to 50%. While significantly improving the gain and bandwidth of the GNSS ceramic antenna, the size and cost are limited. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of a GNSS antenna fence device according to this utility model.

[0020] Figure 2 This is a schematic diagram of the fence structure of a GNSS antenna fence device according to this utility model.

[0021] Figure 3 This is the low-frequency gain diagram of the GNSS antenna fence device in Example 1.

[0022] Figure 4 This is the high-frequency gain diagram of the GNSS antenna fence device in Embodiment 1.

[0023] Figure 5 This is a schematic diagram of another GNSS antenna fence device in this utility model.

[0024] In the diagram: 1. Metal branch; 2. GNSS ceramic antenna; 3. Antenna feed pin clearance hole; 4. GNSS ceramic antenna radiating surface; 5. PCB board; 6. Base plate; 7. Air gap; 8. Support column; 9. Limiting hole; 10. Limiting post. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments:

[0026] Example 1:

[0027] This embodiment is a GNSS antenna fence device, and its installation diagram is as follows. Figure 1 As shown, its overall structure is as follows Figure 2 As shown, the GNSS antenna enclosure device includes a four-sided enclosure structure, a PCB board 5, and a GNSS ceramic antenna 2. The four-sided enclosure structure includes a base plate 6 and a metal fence installed around the base plate. The metal fence includes inclined metal branches 1, which are parallel to each other and separated by air gaps 7. The GNSS ceramic antenna is installed on the top of the base plate, and the PCB board is installed on the bottom of the base plate. The direction of the metal branches is consistent with the direction of the radiating surface 4 of the GNSS ceramic antenna, that is, the GNSS ceramic antenna is installed in the cavity enclosed by the base plate and the metal fence.

[0028] During operation, the tilted metal stubs create a high impedance suppression effect on the cross-polarization components of the GNSS ceramic antenna, suppressing the cross-polarization components of the side lobes and back lobes. Furthermore, the electromagnetic signals are adjusted and optimized through the ends of the stubs, thereby improving the gain of the GNSS antenna.

[0029] The results of the GNSS antenna fence device in this embodiment will be further explained below.

[0030] In this embodiment, the metal fence includes a support post 8, a first branch, and a second branch. One end of the first branch is connected to the support post, and the other end of the first branch is in an open-circuit high-resistance state. The first branch and the support post are designed as an integrated unit. One end of the second branch is connected to the base plate, and the other end of the second branch is an open-circuit structure, forming a high-resistance state. The support post is a vertical columnar structure installed at the four corners of the base plate.

[0031] like Figure 1 and Figure 2 As shown, in this embodiment, there are four first branches and four second branches. The four first branches are parallel to each other, the four second branches are parallel to each other, the first branches and the second branches are parallel, and the air gaps between the first branches and the second branches, the air gaps between the four first branches and the air gaps between the four second branches are all equal.

[0032] Specifically: the air gaps between the metal sections are less than 1 / 10 of the air wavelength, where the air wavelength refers to the distance an electromagnetic wave travels in one vibration cycle. Each metal section of the metal fence is placed parallel to each other and has an angle of inclination ranging from 0° to 90°.

[0033] In this embodiment, the GNSS ceramic antenna has a square structure and a signal feed pin for transmitting the signals received by the GNSS ceramic antenna.

[0034] The base plate has an antenna feed pin clearance hole 3 in the center. The feed pin pin passes through the antenna feed pin clearance hole in the center of the metal base plate and connects to the PCB board at the bottom of the base plate. The base plate is equipped with a fence fixing foot. The metal fence is fixedly connected to the base plate through the fence fixing foot.

[0035] The square shape is only the most preferred option. In other embodiments, the GNSS ceramic antenna can be polygonal, in which case the shape of the base plate and the PCB board will also change to match the GNSS ceramic antenna. Similarly, since the fence is installed around the base plate, the fence structure will also change accordingly.

[0036] The PCB board has a square structure to match the GNSS ceramic antenna. There are limiting holes 9 at the four corners of the PCB board. The base plate has a square structure, and corresponding to the positions of the limiting holes, there are upper limiting posts 10 on the base plate (the limiting posts are evenly distributed around the antenna feed pin clearance hole in the center of the base plate). The PCB board and the base plate are fixedly connected through the limiting holes and limiting posts. The positions of the limiting holes, limiting posts, and fence fixing feet correspond one-to-one.

[0037] Figure 1 In the diagram, the arrows indicate the direction of the metal branches' inclination. There are four metal fences connected end-to-end, and the metal branches of the four fences in a clockwise direction. In other embodiments, the metal branches of the four fences can also in a counter-clockwise direction. The four metal fences do not need to be disconnected from each other; sequential connection yields better results.

[0038] The fencing device in this embodiment consists of a four-sided fencing structure surrounding the GNSS ceramic antenna to limit and optimize the electromagnetic environment around the antenna. The four-sided fencing structure is made of conductive metal material, possessing excellent electromagnetic conduction and shielding properties, effectively guiding the direction of the electromagnetic field generated by the GNSS antenna and reducing the impact of external electromagnetic interference on antenna performance.

[0039] The angle of the metal stub can be adjusted according to actual requirements, and generally 0-60° can have a significant effect. The tilt direction of the metal stub in the metal fence is related to the polarization of the GNSS ceramic antenna placed within the four-sided fence structure. When the polarization of the GNSS ceramic antenna is reversed (the antenna polarization direction refers to the orientation and variation law of its electric field vector in space when the antenna radiates electromagnetic waves. Simply put, the electric field direction of the electromagnetic field radiated by the antenna is the polarization direction of the antenna), the tilt direction of the metal stub also needs to be adjusted.

[0040] In addition, the four-sided fence structure is designed with specific openings and air gaps to adjust the electromagnetic field distribution around the GNSS antenna, further improving the reception performance and positioning accuracy of the GNSS antenna. At the same time, the size and shape of the four-sided fence structure have been optimized to achieve product miniaturization while ensuring performance.

[0041] The working principle of the GNSS antenna fence device provided in this embodiment is as follows:

[0042] The metal fence increases the current path length by designing a toothed structure opposite to the antenna polarization direction. This can simultaneously suppress the radiated current on the antenna surface from flowing to the back of the antenna, suppressing ineffective energy radiation in the rear and improving the radiation effect of effective energy.

[0043] When cross-polarized signal energy flows through the fence to its end, the high impedance state effectively suppresses polarization. Furthermore, when the path reaches a quarter wavelength, the suppression effect is maximized, effectively suppressing multipath signals and improving the antenna's resistance to multipath effects.

[0044] Based on the above structure and working principle, the GNSS antenna fence device provided in this embodiment has the following beneficial effects:

[0045] 1. The GNSS antenna fence device provided in this embodiment optimizes the electromagnetic field distribution of the GNSS ceramic antenna by adding a metal fence around it, suppressing sidelobe and backlobe signals as well as cross-polarization components. By optimizing the fence structure, the energy recovery in the non-main lobe direction of the GNSS ceramic antenna is improved, and the fence volume only increases the total size of the antenna by 5% to 15%, but the effective antenna gain can be improved by 1 to 3 dB and the bandwidth can be increased by more than 30 to 50%.

[0046] 2. The air gap structure of the fence structure is also used to adjust the electromagnetic field distribution and phase around the antenna, effectively reducing multipath effects and further improving the antenna's receiving performance and positioning accuracy. At the same time, the size and shape of the fence structure have been optimized to achieve product miniaturization while ensuring performance.

[0047] 3. The fence has a simple structure, is easy to install and adjust, and is highly adaptable. It can be made using an integrated sheet metal process, which can reduce costs by more than 50% compared to the traditional integrated cavity structure.

[0048] 4. Supports dynamic adjustment of polarization direction. By adjusting the tilt angle and direction of the fence, it can be adapted to antennas of different polarization types.

[0049] Example 2:

[0050] This embodiment provides a GNSS antenna fence device, which is further optimized based on Embodiment 1, and uses specific data to further illustrate the beneficial effects of the GNSS antenna fence device.

[0051] While achieving high gain performance, existing GNSS antennas often suffer from large size and complex structure, which significantly limits their application in scenarios with high requirements for device size and portability. Therefore, the current technological challenge is how to effectively suppress non-main lobe signal interference and cross-polarization components while maintaining miniaturization and improving gain.

[0052] The GNSS antenna fence device in this embodiment includes a PCB board, a base plate on the PCB board, a GNSS ceramic antenna on the base plate, and a metal fence installed around the base plate. The metal fence includes inclined metal branches that are parallel to each other and are separated by air gaps.

[0053] The main body of the fence includes four serrated metal branches, containing both metal branches and air gaps; the bottom plate of the fence is used to connect the four metal branches and form a radio frequency grounding structure.

[0054] Specifically:

[0055] The GNSS antenna enclosure consists of a five-sided metal enclosure cavity. The GNSS ceramic antenna is mounted inside the cavity. The five-sided metal enclosure cavity includes a square base plate and four sheet metal sections mounted around the base plate. These sheet metal sections are divided into inclined metal segments, each including an L-shaped support column. The bottom of the support column is connected to the base plate and mounted on its side. One end of each metal segment is connected to a support column, while the other end is in an open-circuit, high-impedance state, forming the metal enclosure. There are non-contact air gaps between the metal segments. Each metal segment is placed parallel to each other and tilted at an angle of 0-90°. The gaps between the metal segments are less than 1 / 10 of the air wavelength. The base plate is connected to both the GNSS ceramic antenna and the PCB board.

[0056] In this embodiment, the base plate has a square structure, and a limiting post is provided at each of the four corners of the base plate. The limiting post penetrates through the base plate, and there is a protruding structure on the bottom of the base plate. The limiting hole on the PCB board is fixed to the protruding structure on the bottom of the base plate, thereby realizing the fixed connection between the PCB board and the base plate.

[0057] When using this GNSS antenna fence device, place the base plate between the GNSS ceramic antenna and the PCB board, with the metal branches of the metal fence facing the GNSS ceramic antenna side. The performance of the GNSS ceramic antenna can be optimized by adjusting the tilt angle, length, and size of the metal branches.

[0058] When the GNSS ceramic antenna is installed inside the metal enclosure cavity during operation, the tilted metal stubs will create a high impedance suppression effect on the cross-polarization component of the GNSS ceramic antenna, which can suppress the cross-polarization components of the side lobes and back lobes, and adjust and optimize the electromagnetic signal through the end of the stubs.

[0059] In this embodiment, the dimensions of the metal fence cavity are 40mm×40mm×10mm (compatible with a 35mm*35mm*10mm dual-band ceramic antenna), that is, each metal fence is 40mm long and 10mm high, and the tilt angle of the metal branches of the four metal fences is clockwise.

[0060] This embodiment primarily focuses on GNSS ceramic antennas, specifically microstrip antennas using ceramic substrates. These antennas generally have poor performance and low peak gain. Other embodiments may employ other types of GNSS antennas or antennas operating in other frequency bands.

[0061] Therefore, the fence device provided in this embodiment is used to test the gain of the GNSS ceramic antenna. The gain in the low-frequency band is as follows: Figure 3 As shown in the figure, the vertical axis represents the right-hand circular polarization gain. The solid line represents the right-hand circular polarization gain obtained using the fencing device provided in this embodiment, and the dashed line represents the right-hand circular polarization gain obtained without using the fencing device. In the high-frequency band, the gain is as follows: Figure 4 As shown in the figure, the vertical axis represents the right-hand polarization gain, the solid line represents the right-hand polarization gain obtained using the fence device provided in this embodiment, and the dashed line represents the right-hand polarization gain obtained without using the fence device.

[0062] from Figure 3 and Figure 4 It can be clearly seen that the gain of the GNSS antenna is significantly improved by using the fence device provided in this embodiment.

[0063] Specifically, will Figure 3 and Figure 4 The data was extracted and calculated to obtain the following table:

[0064]

[0065]

[0066] according to Figure 3 , Figure 4 As shown in the table above, for the same GNSS antenna, after adding the metal fence provided in this embodiment, the antenna gain increased by 2 to 4 dB, and the effective bandwidth of the GNSS antenna was significantly increased, but the volume only increased by 14.3%.

[0067] Therefore, the GNSS antenna fence device provided in this embodiment can achieve product miniaturization while ensuring the performance (gain and bandwidth) of the GNSS antenna.

[0068] Example 3:

[0069] This embodiment provides a GNSS antenna fence device, including a fence structure, a PCB board, and a GNSS ceramic antenna. The fence structure includes a base plate and a metal fence installed around the base plate. The metal fence includes inclined metal branches that are parallel to each other and separated by air gaps. The GNSS ceramic antenna is mounted on the PCB board and has a feed pin for transmitting signals. The feed pin is connected to the PCB board, and the PCB board is fixedly installed in the cavity formed by the base plate and the metal fence.

[0070] The base plate is equipped with fence fixing feet, and the metal fence is connected to the base plate through the fence fixing feet.

[0071] One end of the metal branch is fixedly connected to the base plate, while the other end of the metal branch is an open circuit structure, resulting in a high resistance state during travel.

[0072] In this embodiment, the fence structure is a quadrilateral (square) structure, and the metal branches are tilted in a counterclockwise direction.

[0073] In other embodiments, the fence structure can also be a polygonal structure such as a pentagon or hexagon. The fence structure varies with the base plate structure, which is consistent with the PCB board and GNSS ceramic antenna.

[0074] Each metal branch on the fence is placed parallel to each other with an angle ranging from 0 to 90 degrees. The air gap between the metal branches is less than 1 / 10 of the air wavelength. The lower end of the metal branch is integrally connected to the sheet metal base plate, and the upper end of the metal branch is in an open circuit high-resistance state.

[0075] During operation, the tilted metal stubs create a high impedance suppression effect on the cross-polarization components of the GNSS ceramic antenna, suppressing the cross-polarization components of the side lobes and back lobes. Furthermore, the electromagnetic signals are adjusted and optimized through the ends of the stubs, thereby improving the gain of the GNSS antenna.

[0076] Example 4:

[0077] This embodiment provides a GNSS antenna fence device, such as Figure 5As shown, the device includes a metal base plate and a metal fence mounted on the base plate. The metal fence includes inclined metal branches that are parallel to each other. One end of each metal branch is connected to the metal base plate, and the other end of each metal branch is in an open-circuit high-resistance state. The metal branches are separated by air gaps, and the air gaps between each metal branch are equal. A GNSS antenna device is mounted on the metal base plate.

[0078] Specifically:

[0079] In this embodiment, the metal fence is a circular structure, and the metal branches in the metal fence are tilted in a clockwise or counterclockwise direction.

[0080] Each metal branch on the fence is placed parallel to each other with an angle ranging from 0° to 90°. The air gap between the metal branches is less than 1 / 10 of the air wavelength. The lower end of each metal branch is integrally connected to the sheet metal base plate, while the upper end of the metal branch is in an open-circuit high-impedance state. The GNSS antenna device includes a GNSS ceramic antenna and a PCB board. The GNSS ceramic antenna is mounted on top of the metal base plate, and the PCB board is mounted on the bottom of the metal base plate. The metal base plate has an antenna feed pin clearance hole in the center. The antenna feed pin on the GNSS ceramic antenna is connected to the PCB board through the antenna feed pin clearance hole to transmit the signal.

[0081] Support columns are evenly arranged around the antenna feed pin clearance hole on the metal base plate. Limiting holes are provided on the PCB board at the corresponding positions of the support columns. The PCB board and the metal base plate are fixedly connected by the cooperation of the support columns and the limiting holes.

[0082] The metal fence increases the current path length by designing a toothed structure opposite to the polarization direction of the GNSS antenna. This can simultaneously suppress the radiated current on the surface of the GNSS antenna from flowing to the back of the antenna, suppress ineffective energy radiation in the rear direction, and improve the radiation effect of effective energy.

[0083] When cross-polarized signal energy flows through the metal fence to its end, the high impedance effectively suppresses polarization. Furthermore, when the path reaches a quarter wavelength, the suppression effect is maximized, effectively suppressing multipath signals and improving the GNSS antenna's resistance to multipath effects.

[0084] The embodiments described above are merely preferred solutions of this utility model and are not intended to limit this utility model in any way. Other variations and modifications are possible without departing from the technical solutions described in the claims.

Claims

1. A GNSS antenna enclosure device, characterized by The metal fence includes a bottom plate and a metal fence installed on the bottom plate, the metal fence includes inclined metal branches, the metal branches are parallel to each other, one end of the metal branches is connected with the bottom plate, the other end of the metal branches is in an open-circuit high-resistance state, the metal branches are separated by air gaps, and a GNSS antenna device is installed on the bottom plate.

2. A GNSS antenna enclosure device according to claim 1, wherein, The metal fence is a polygonal structure, and the inclined direction of the metal branches in the metal fence is clockwise or counterclockwise.

3. The GNSS antenna enclosure of claim 1, wherein, The metal fence is a circular structure, and the inclined direction of the metal branches in the metal fence is clockwise or counterclockwise.

4. A GNSS antenna enclosure apparatus according to claim 2, wherein, The metal fence includes a support column, the metal branches include first branches and second branches, one end of the first branches is in an open-circuit high-resistance state, the other end of the first branches is integrally connected with the support column, one end of the second branches is connected with the bottom plate, and the other end of the second branches is in an open-circuit high-resistance state.

5. The GNSS antenna enclosure apparatus of claim 1 or 2 or 3 or 4, wherein, The air gap between the metal branches is less than 1 / 10 of the air wavelength.

6. The GNSS antenna enclosure apparatus of claim 1 or 2 or 3 or 4, wherein, The inclination angle of the metal branches is 0-90 degrees.

7. A GNSS antenna enclosure device according to claim 4, wherein, The first branches are parallel to the second branches, the first branches are parallel to each other, the second branches are parallel to each other, the air gap between the first branches and the air gap between the second branches are equal.

8. The GNSS antenna enclosure of claim 1 or 2 or 3 or 4 or 7, wherein, The GNSS antenna device includes a GNSS ceramic antenna and a PCB board, the bottom plate is installed between the GNSS ceramic antenna and the PCB board, and the GNSS ceramic antenna is installed in a cavity surrounded by the bottom plate and the metal fence.

9. A GNSS antenna enclosure device according to claim 8, wherein, The bottom plate is provided with an antenna feed needle avoiding hole in the center, and is provided with a fence fixing foot, and the metal fence is connected with the bottom plate through the fence fixing foot.

10. The GNSS antenna enclosure apparatus of claim 1 or 2 or 3 or 4 or 7, wherein, The GNSS antenna device includes a GNSS ceramic antenna and a PCB board, and the GNSS ceramic antenna and the PCB board are installed in a cavity surrounded by the bottom plate and the metal fence.

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