A v2x antenna device and a terminal

Abstract

This invention discloses a V2X antenna device and terminal. The V2X antenna device includes: a substrate, an antenna element, a ground patch, a microstrip power divider, a core wire pad, and a ground pad. The substrate has a first surface and a second surface opposite each other in the thickness direction. The antenna element includes a first antenna array and a second antenna array disposed on the first surface of the substrate. The ground patch is connected to the first antenna array and the second antenna array respectively. The microstrip power divider includes a first microstrip line and a second microstrip line disposed on the second surface of the substrate. The core wire pad is connected to the microstrip power divider, and the ground pad is connected to the ground patch. The core wire pad and the ground pad are connected by the core wire of a coaxial cable. This V2X antenna device adopts the form of a printed antenna, which has a simple antenna structure, low cost, small size, light weight, and convenient installation and fixing advantages. The antenna has good gain performance and good horizontal omnidirectional characteristics throughout the entire operating frequency band.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and in particular to a V2X antenna device and terminal. Background Technology

[0002] With the rise of intelligent transportation systems, the widespread adoption of V2X (Vehicle to Everything), and the development of 5G IoT technology, V2X, in a broader sense, will become more closely integrated with transportation, becoming a crucial component of intelligent transportation. In various application scenarios brought about by V2X vehicle-to-everything (V2X) connectivity, such as autonomous driving, smart mobility, and integrated logistics, vehicles can be viewed as mobile network nodes. Each node possesses mobility, and their collaboration effectively reduces blind spots, avoids accidents, and thus improves the overall efficiency of the transportation system, reduces energy consumption, and increases the safety and convenience of transportation. However, this places high demands on the antenna gain, bandwidth, and omnidirectionality of V2X antennas (frequency band: 5.85GHz~5.925GHz), increasing the design complexity of the antennas.

[0003] Currently, V2X vehicle antennas are mostly located in the front and rear sections inside a vehicle. Space constraints necessitate miniaturization of these antennas, leading to the use of active antennas to address and improve performance. However, the higher cost of active antennas limits their widespread adoption. Existing V2X antennas also suffer from low gain and poor horizontal omnidirectional performance. Increasing antenna size is the only way to achieve better gain and omnidirectional radiation performance, but this larger size may prevent installation in practical environments. Summary of the Invention

[0004] The purpose of this invention is to provide a V2X antenna device and terminal that achieves antenna miniaturization while possessing good antenna electrical performance.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A V2X antenna device, comprising:

[0007] The substrate has a first surface and a second surface that are opposite each other in the thickness direction;

[0008] The antenna unit includes a first antenna array and a second antenna array disposed on the first surface of the substrate, wherein the first antenna array and the second antenna array are symmetrically disposed about a first line;

[0009] A grounding patch is disposed on the first surface of the substrate, and the grounding patch is respectively connected to the first antenna array and the second antenna array;

[0010] A microstrip power divider includes a first microstrip line and a second microstrip line disposed on the second surface of the substrate. The first microstrip line and the second microstrip line are symmetrically arranged about the first line and are used to couple and feed the first antenna array and the second antenna array, respectively.

[0011] The core wire pad, the grounding pad, and the coaxial cable are all disposed on the second surface of the substrate. The microstrip power divider is connected to the core wire of the coaxial cable through the core wire pad. The grounding pad is connected to the grounding patch. The grounding pad is also connected to the shielding layer of the coaxial cable.

[0012] In one alternative, the spacing between the first antenna array and the second antenna array is 1 / 2 to 3 / 4 of the air distance wavelength.

[0013] When the spacing between antenna elements is within the range of 1 / 2 to 3 / 4 of the air distance wavelength, the greater the distance, the higher the antenna gain, and the less mutual interference between antenna elements. Preferably, the spacing between the first antenna element 21 and the second antenna element 22 is 3 / 4 of the air distance wavelength, within which the antenna electrical performance of the V2X antenna device is better.

[0014] In an alternative embodiment, the structure of the first antenna array is the same as that of the second antenna array. Both the first antenna array and the second antenna array include an upper arc patch and a lower arc patch arranged symmetrically against each other, with a gap between the upper arc patch and the lower arc patch.

[0015] The semi-circular patch structure, compared to a right-angle antenna array, results in a shorter path, less loss, and is more conducive to high-efficiency antenna radiation. Furthermore, the microstrip power divider generates coupled feed through slots, a simple and highly efficient method.

[0016] In an alternative embodiment, the lower arc patch of the first antenna array is connected to one side of the ground patch via a first connecting strip;

[0017] The upper arc patch of the second antenna array is connected to the other side of the grounding patch via a second connecting strip;

[0018] Both the upper and lower arc patches are semi-circular arc patches, and the distance between the upper and lower arc patches is 0.5-2mm.

[0019] By using a first connecting strip and a second connecting strip to connect the first antenna array, the second antenna array, and the grounding patch, the overall length of the antenna can be shortened, which is beneficial for the miniaturization of the antenna.

[0020] In an alternative embodiment, the microstrip power divider further includes a microstrip line stub located between the junction of the first microstrip line and the second microstrip line and the core wire pad.

[0021] By adjusting the length of the microstrip line stub (the length direction of the microstrip line stub is consistent with the length direction of the substrate), good impedance matching can be obtained, thereby improving the antenna electrical performance of the V2X antenna device.

[0022] In an alternative embodiment, a first protruding stub is provided on the first microstrip line;

[0023] The second microstrip line is provided with a second protruding branch.

[0024] In an alternative embodiment, the microstrip power divider is 180° out of phase.

[0025] By setting the first and second protruding stubs, impedance matching can be easily debugged, thereby reducing the debugging difficulty and improving operability compared to changing the linewidth of the entire first and / or second microstrip line.

[0026] In one alternative embodiment, the substrate has a T-shaped structure, the substrate includes a connected horizontal portion and a vertical portion, the antenna unit, a portion of the ground patch, and a portion of the microstrip power divider are disposed in the vertical portion of the substrate, and the core wire pad and the ground pad are disposed in the horizontal portion of the substrate.

[0027] In one alternative embodiment, the lateral portion of the substrate has a length of 14-18 mm and a width of 12-16 mm;

[0028] The vertical portion of the substrate has a length of 56-60 mm and a width of 12-16 mm.

[0029] Without compromising the antenna's electrical performance, this size range enables the miniaturization of the antenna, solving the problems of V2X antenna device installation and layout.

[0030] A terminal comprising the aforementioned V2X antenna device.

[0031] Terminals that include the above-mentioned V2X antenna device have the advantages of small size and good antenna electrical performance.

[0032] Compared with the prior art, the beneficial effects of the present invention include at least the following:

[0033] 1. It adopts a printed antenna design, which makes the antenna structure simple to manufacture, low in cost, small in size, and light in weight, and has the advantage of being easy to install and fix.

[0034] 2. The antenna has good gain performance, good horizontal omnidirectional characteristics, and broadband characteristics throughout the entire operating frequency band. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure on the first side of the V2X antenna device according to an embodiment of the present invention.

[0036] Figure 2 This is a schematic diagram of the structure on the second side of the V2X antenna device according to an embodiment of the present invention.

[0037] Figure 3 This is a graph showing the test results of the voltage standing wave ratio (VSWR) of the V2X antenna device according to an embodiment of the present invention.

[0038] Figure 4 This is the radiation pattern of the V2X antenna device according to an embodiment of the present invention at the 5.85 GHz frequency.

[0039] Figure 5 This is the radiation pattern of the V2X antenna device in this embodiment of the invention at a frequency of 5.905 GHz.

[0040] Figure 6 This is the radiation pattern of the V2X antenna device according to an embodiment of the present invention at a frequency of 5.925 GHz.

[0041] Figure 7 This is a simulation result diagram of the antenna radiation efficiency of the V2X antenna device according to an embodiment of the present invention.

[0042] Figure 8 This is the radiation pattern of a V2X antenna device using a right-angle antenna array at a frequency of 5.905 GHz.

[0043] Figure 9 The radiation pattern of a V2X antenna at 5.905 GHz is given when the distance to the air is half the wavelength.

[0044] Figure 10 The graph shows the test results of the voltage standing wave ratio of the V2X antenna device when the distance to the air is half the wavelength.

[0045] Figure 11 This is a graph showing the test results of the voltage standing wave ratio (VSWR) of a V2X antenna device without microstrip stubs.

[0046] In the diagram: 1. Substrate; 11. Lateral section; 12. Vertical section; 13. First line; 2. Antenna element; 21. First antenna array; 22. Second antenna array; 23. Slot; 3. Grounding patch; 4. Microstrip power divider; 41. First microstrip line; 411. First protruding stub; 42. Second microstrip line; 421. Second protruding stub; 43. Microstrip line stub; 5. Core wire pad; 6. Grounding pad; 7. First connecting strip; 8. Second connecting strip; 9. Coaxial cable. Detailed Implementation

[0047] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided to make the invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore repeated descriptions of them will be omitted.

[0048] The terms used to express position and direction in this invention are illustrated with reference to the accompanying drawings, but changes can be made as needed, and all such changes are included within the scope of protection of this invention.

[0049] See Figure 1-2 As shown, the present invention provides a V2X antenna device, including: a substrate 1, an antenna element 2, a ground patch 3, a microstrip power divider 4, a core wire pad 5, a ground pad 6, and a coaxial cable 9.

[0050] The substrate 1 can be made of FR4 material (epoxy resin board) with a dielectric constant of 4.2 and a loss tangent of 0.02. The substrate 1 has a first surface and a second surface opposite each other in the thickness direction. The first surface is used to print the antenna element 2 and the ground patch 3, and the second surface is used to print the microstrip power divider 4. Specifically, the substrate 1 has a T-shaped structure, including a connected horizontal portion 11 and a vertical portion 12. The antenna element 2, part of the ground patch 3, and part of the microstrip power divider 4 are disposed in the vertical portion 12 of the substrate 1, and the core wire pad 5 and the ground pad 6 are disposed in the horizontal portion 11 of the substrate 1. By adopting a printed antenna design, the antenna structure is simple to manufacture, easy to process, and has a low cost.

[0051] Antenna element 2 includes a first antenna element 21 and a second antenna element 22 disposed on the first surface of substrate 1. The first antenna element 21 and the second antenna element 22 are symmetrically arranged about a first line 13, which can be the center line along the length of substrate 1. With the help of a microstrip power divider 4, a 180° phase difference can be generated between the first antenna element 21 and the second antenna element 22, ensuring that the first antenna element 21 and the second antenna element 22 can radiate in the same direction, giving them good horizontal omnidirectional characteristics. The structure of the first antenna element 21 is the same as that of the second antenna element 22. Both the first antenna element 21 and the second antenna element 22 include an upper arc patch and a lower arc patch arranged symmetrically against each other, with a gap 23 between them. Both the upper and lower arc patches are semi-circular arc patches. This semi-circular arc patch structure results in a shorter path and less loss compared to a right-angle antenna element, which is more conducive to high-efficiency antenna radiation. (See also...) Figure 8 As shown, Figure 8 This is the radiation pattern of a V2X antenna array using a right-angle antenna array at 5.905 GHz. As shown in the figure, right-angle bends should be avoided as much as possible in the RF circuitry, especially at high frequencies where the impact is significant; only with lower losses can gain be improved. For example, see the simulation results at a center frequency of 5.905 GHz. Figure 6 As shown, the V2X antenna device in this embodiment, after adopting a semi-circular arc antenna array, will have a gain improvement of up to 0.5 dBi.

[0052] A grounding patch 3 is disposed on the first surface of the substrate 1, and the grounding patch 3 is connected to the first antenna array 21 and the second antenna array 22 respectively. Specifically, the lower arc patch of the first antenna array 21 is connected to one side of the grounding patch 3 through the first connecting strip 7, and the upper arc patch of the second antenna array 22 is connected to the other side of the grounding patch 3 through the second connecting strip 8. This shortens the overall length of the antenna and facilitates the miniaturization of the antenna.

[0053] The microstrip power divider 4 has a 180° phase difference. It includes a first microstrip line 41 and a second microstrip line 42 disposed on the second surface of the substrate 1. The first microstrip line 41 and the second microstrip line 42 are symmetrically arranged about the first line 13 and are used to couple and feed the first antenna element 21 and the second antenna element 22, respectively. The microstrip power divider 4 can generate coupled feeding to the gap 23 between the upper and lower arcuate patches of the first antenna element 21 and the gap 23 between the upper and lower arcuate patches of the second antenna element 22. The coupled feeding method is simple and highly efficient.

[0054] The core wire pad 5, the grounding pad 6, and the coaxial cable 9 are all disposed on the second surface of the substrate 1. The microstrip power divider 4 is connected to the core wire of the coaxial cable 9 through the core wire pad 5. The grounding pad 6 is connected to the grounding patch 3. The grounding pad 6 is also connected to the shielding layer of the coaxial cable 9.

[0055] In the aforementioned V2X antenna device, the microstrip power divider 4 splits into two paths on the second surface of the substrate 1. The first microstrip line 41 and the second microstrip line 42 respectively couple and feed the first antenna array 21 and the second antenna array 22 on the first surface of the substrate 1. The microstrip power divider 4 creates a 180° phase difference between the first antenna array 21 and the second antenna array 22, ensuring that the two antenna arrays can radiate in the same direction. The grounding pad 6 can be connected to the grounding patch 3 through a metallized via. The microstrip power divider 4 is connected to the core wire of the coaxial cable 9 through the core wire pad 5, thus forming a parallel array antenna structure.

[0056] In one specific embodiment, the spacing between the first antenna element 21 and the second antenna element 22 is 1 / 2 to 3 / 4 of the air distance wavelength.

[0057] First, let's explain the concept of wavelength in air. Wavelength λ is equal to the product of wave speed V and period T. The same frequency travels at different speeds in different media, resulting in different wavelengths. Here, the medium is air, which is the distance an electromagnetic wave travels through the air. When the spacing between antenna elements is within 1 / 2 to 3 / 4 of the air distance wavelength, the greater the distance, the higher the antenna gain, and the less mutual interference between the antenna elements. See also... Figures 9-10 As shown, Figure 9 The radiation pattern of a V2X antenna at 5.905 GHz is given when the air distance is half the wavelength. Figure 10 The graph shows the test results of the voltage standing wave ratio (VSWR) of the V2X antenna device when the distance between the first antenna element 21 and the second antenna element 22 is 1 / 2 the distance between the air wavelengths. As can be seen from the graph, when the distance between the first antenna element 21 and the second antenna element 22 is 1 / 2 the distance between the air wavelengths, the first antenna element 21 and the second antenna element 22 are closer together, and the degree of mutual interference increases, which will inevitably lead to a decrease in gain (the simulation results are taken as an example with a center frequency of 5.905 GHz), and the antenna VSWR will also deteriorate.

[0058] In this embodiment, the spacing between the first antenna element 21 and the second antenna element 22 is 3 / 4 of the air distance wavelength. (See [reference]). Figure 6 As shown, the radiation pattern of the V2X antenna device at the 5.905 GHz frequency point is shown. It can be seen from the figure that the antenna electrical performance of the V2X antenna device is good at this time.

[0059] In one specific embodiment, the microstrip power divider 4 further includes a microstrip line stub 43, which is located between the junction of the first microstrip line 41 and the second microstrip line 42 and the core wire pad 5.

[0060] By adjusting the length of the microstrip line stub 43 (the length direction of the microstrip line stub 43 is consistent with the length direction of the substrate 1), good impedance matching can be obtained, thereby improving the antenna electrical performance of the V2X antenna device. See also... Figure 11 As shown, Figure 11 This is a graph showing the test results of the voltage standing wave ratio (VSWR) of a V2X antenna device without the microstrip stub 43. As can be seen from the graph, the VSWR of the antenna lacking the microstrip stub 43 is worse than before, which means that the antenna impedance is worse and cannot achieve better impedance matching.

[0061] In one specific embodiment, a first protruding branch 411 is provided on the first microstrip line 41, and a second protruding branch 421 is provided on the second microstrip line 42.

[0062] The first protruding stub 411 and the second protruding stub 421 are both symmetrical from left to right. That is, the first protruding stub 411 is symmetrical with respect to the center line of the length direction of the first microstrip line 41, and the second protruding stub 421 is symmetrical with respect to the center line of the length direction of the second microstrip line 42. By setting the first protruding stub 411 and the second protruding stub 421, it is convenient to actually debug impedance matching, thereby reducing the debugging difficulty. Compared with changing the linewidth of the entire first microstrip line 41 and / or the second microstrip line 42, the operability is improved.

[0063] In one specific embodiment, the length (along the length direction of the substrate 1) of the horizontal portion 11 of the substrate 1 is 14-18 mm and the width (along the width direction of the substrate 1) is 12-16 mm. The length (along the length direction of the substrate 1) of the vertical portion 12 of the substrate 1 is 56-60 mm and the width (along the width direction of the substrate 1) is 12-16 mm. The distance between the upper arc patch and the lower arc patch is 0.5-2 mm. When the upper arc patch and the lower arc patch are semi-circular arc patches, the radius of the semi-circular arc patch is 3.5-5.5 mm.

[0064] As an example, the substrate 1 has an overall length of 58mm, a width of 28mm, and a thickness of 1mm. The horizontal portion 11 of the substrate 1 has a length of 16mm and a width of 14mm, and the vertical portion 12 of the substrate 1 has a length of 58mm and a width of 14mm. This size allows for overall antenna miniaturization without affecting the antenna's electrical performance, solving the installation and layout problems of V2X antenna devices. Furthermore, the distance between the upper and lower arc-shaped patches is 1mm to achieve high-efficiency coupling feed. When the upper and lower arc-shaped patches are semi-circular, the radius of the semi-circular patch is 4.5mm to reduce antenna loss and improve antenna radiation efficiency.

[0065] The following is combined Figures 3-7 The test performance of the above-mentioned V2X antenna device is explained. As shown in the figure, the HFSS simulation results demonstrate that the V2X antenna device exhibits: S11 output VSWR ≤ 1.2 (frequency band: 5.85GHz~5.925GHz), E-plane gain ≥ 4.0dBi, antenna non-circularity ≤ 2dB, antenna radiation efficiency > 80%, and good gain performance, good horizontal omnidirectional characteristics, and broadband characteristics. The V2X antenna device of this invention, while achieving miniaturization, possesses good gain performance, good omnidirectional characteristics, and good broadband characteristics. It also has an H-plane non-circularity of less than 2dB, is small in size and lightweight, and can be installed in multiple areas of a vehicle interior, such as rearview mirrors, spoilers, front bumpers, and rear bumpers, where there are no metal obstructions.

[0066] The present invention also provides a terminal, such as a vehicle-mounted antenna device, which includes the above-mentioned V2X antenna device and has the advantages of small size and good antenna electrical performance.

[0067] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the invention without departing from the principles and spirit of the invention, and all such changes should fall within the protection scope of the claims of the present invention.

Claims

1. A V2X antenna device, characterized by, include: The substrate has a first surface and a second surface that are opposite each other in the thickness direction; The antenna unit includes a first antenna array and a second antenna array disposed on the first surface of the substrate, wherein the first antenna array and the second antenna array are symmetrically disposed about a first line; A grounding patch is disposed on the first surface of the substrate, and the grounding patch is respectively connected to the first antenna array and the second antenna array; A microstrip power divider includes a first microstrip line and a second microstrip line disposed on the second surface of the substrate. The first microstrip line and the second microstrip line are symmetrically arranged about the first line and are used to couple and feed the first antenna array and the second antenna array, respectively. The core wire pad, the grounding pad, and the coaxial cable are all disposed on the second surface of the substrate. The microstrip power divider is connected to the core wire of the coaxial cable through the core wire pad. The grounding pad is connected to the grounding patch. The grounding pad is also connected to the shielding layer of the coaxial cable. The structure of the first antenna array is the same as that of the second antenna array. Both the first antenna array and the second antenna array include an upper arc patch and a lower arc patch arranged symmetrically against each other, and there is a gap between the upper arc patch and the lower arc patch. The lower arc patch of the first antenna array is connected to one side of the ground patch via a first connecting strip; The upper arc patch of the second antenna array is connected to the other side of the grounding patch via a second connecting strip; Both the upper and lower arc patches are semi-circular arc patches, and the distance between the upper and lower arc patches is 0.5-2mm.

2. The V2X antenna device of claim 1, wherein, The distance between the first antenna array and the second antenna array is 1 / 2 to 3 / 4 of the air distance wavelength.

3. The V2X antenna device according to claim 1, characterized in that, The microstrip power divider also includes a microstrip line stub, which is located between the junction of the first microstrip line and the second microstrip line and the core wire pad.

4. The V2X antenna device according to claim 1, characterized in that, The first microstrip line is provided with a first protruding branch; The second microstrip line is provided with a second protruding branch.

5. The V2X antenna device according to claim 1, characterized in that, The phase difference of the microstrip power divider is 180°.

6. The V2X antenna device according to claim 1, characterized in that, The substrate has a T-shaped structure and includes a connected horizontal portion and a vertical portion. The antenna unit, part of the grounding patch, and part of the microstrip power divider are disposed in the vertical portion of the substrate, and the core wire pad and the grounding pad are disposed in the horizontal portion of the substrate.

7. The V2X antenna device according to claim 1, characterized in that, The lateral portion of the substrate has a length of 14-18 mm and a width of 12-16 mm; The vertical portion of the substrate has a length of 56-60 mm and a width of 12-16 mm.

8. A terminal, characterized in that, The terminal includes the V2X antenna device as described in any one of claims 1-7.

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