High-isolation vehicle-mounted 5G antenna structure and vehicle-mounted antenna

Abstract

This disclosure provides a high-isolation vehicle-mounted 5G antenna structure and an vehicle-mounted antenna. The high-isolation vehicle-mounted 5G antenna structure includes a PCB substrate and a GNSS antenna module disposed thereon, at least one 5G full-band main antenna, at least one 5G full-band diversity antenna, and at least two 5G MIMO antennas. The PCB substrate has at least one ground isolation region located between adjacent 5G full-band main and diversity antennas, and / or between two 5G MIMO antennas. The PCB substrate also has at least one first and one second current-blocking grounding structure, respectively disposed near the feed terminals of the 5G full-band main and diversity antennas. This structure cuts off the direct conduction path of stray surface currents through the ground isolation region, and the first and second current-blocking grounding structures disrupt the uniform distribution of surface currents and generate impedance loss, synergistically blocking stray surface currents, reducing signal crosstalk, and thereby improving the isolation between antennas.

Description

Technical Field

[0001] This disclosure relates to the technical field of vehicle-mounted antennas, and in particular to a high-isolation vehicle-mounted 5G antenna structure and vehicle-mounted antenna. Background Technology

[0002] With the rapid iteration of vehicle-to-everything (V2X) and intelligent driving technologies, the requirements for data transmission rates, positioning accuracy, and multi-signal coordination capabilities of in-vehicle communication systems are continuously increasing. The integrated application of 5G communication technology and GNSS positioning technology has become a core configuration direction for in-vehicle electronic devices. To meet the multi-service needs in in-vehicle scenarios, in-vehicle antennas typically need to integrate multiple functional units such as 5G main diversity antennas and GNSS antennas to achieve synchronous signal reception and transmission.

[0003] However, when external 5G signals and GNSS satellite signals are captured by the antenna, the antenna's radiating elements generate induced electrical signals, and stray surface currents are generated on the PCB substrate surface due to electromagnetic induction. If these stray surface currents are allowed to conduct freely, they can easily cause signal crosstalk between adjacent antennas, particularly severely affecting the stability of low-frequency signals. In traditional designs, due to the lack of effective isolation methods, stray surface currents can easily flow between different antennas, causing low-frequency signals to couple through the PCB stray surface currents. These stray surface currents flow from the radiating area of ​​one antenna to the signal receiving area of ​​another module, leading to serious signal interference problems and making it difficult for the isolation between antennas when receiving signals to reach an ideal level.

[0004] Therefore, there is an urgent need to develop a high-isolation vehicle-mounted 5G antenna structure that can effectively improve the isolation of each antenna and reduce interference between signals. Utility Model Content

[0005] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide a high isolation vehicle-mounted 5G antenna structure and vehicle-mounted antenna that improves isolation by setting a ground isolation area to reduce stray current on the PCB substrate surface.

[0006] The purpose of this disclosure is achieved through the following technical solution:

[0007] A high-isolation vehicle-mounted 5G antenna structure includes a PCB substrate, a GNSS antenna module disposed on the PCB substrate, at least one 5G full-band main antenna, at least one 5G full-band diversity antenna, and at least two 5G MIMO antennas. At least one ground isolation area is disposed on the PCB substrate, the ground isolation area being disposed between any two adjacent 5G full-band main antennas and 5G full-band diversity antennas, and / or, the ground isolation area being disposed between any two adjacent 5G MIMO antennas.

[0008] The PCB substrate is further provided with at least one first current-blocking grounding structure and at least one second current-blocking grounding structure. Each first current-blocking grounding structure is disposed adjacent to the feed end of the 5G full-band main antenna, and each second current-blocking grounding structure is disposed adjacent to the feed end of the 5G full-band diversity antenna.

[0009] Each of the 5G full-band main antenna, each of the 5G full-band diversity antennas and each of the 5G MIMO antennas has its feed terminal electrically connected to a connector. The GNSS antenna module is fixed on the side of the PCB substrate away from the ground isolation area and is electrically connected to a connector.

[0010] In one embodiment, the 5G full-band main antenna is a monopole main antenna, the 5G full-band diversity antenna is a monopole diversity antenna, and the 5G full-band main antenna and the 5G full-band diversity antenna are respectively vertically fixed to the two long sides of the PCB substrate.

[0011] In one embodiment, the two 5G MIMO antennas are a first MIMO PIFA antenna and a second MIMO PIFA antenna, respectively. The first MIMO PIFA antenna and the second MIMO PIFA antenna are respectively vertically fixed to the two long sides of the PCB substrate and are offset from the 5G full-band main antenna and the 5G full-band diversity antenna.

[0012] In one embodiment, the second MIMO PIFA antenna is provided with a ground-coupled stub.

[0013] In one embodiment, the first current-blocking grounding structure is a T-type structure.

[0014] In one embodiment, the first current-blocking grounding structure includes a horizontal branch and a vertical branch, the horizontal branch being perpendicular to the vertical branch, the length of the horizontal branch being 3mm to 10mm, and the length of the vertical branch being 5mm to 20mm.

[0015] In one embodiment, the second current-blocking grounding structure is a concave structure.

[0016] In one embodiment, the second current-blocking grounding structure includes a first current-blocking branch and a second current-blocking branch, the first current-blocking branch and the second current-blocking branch are arranged parallel to each other, and the distance between the first current-blocking branch and the second current-blocking branch is in the range of 5mm to 15mm.

[0017] In one embodiment, the GNSS antenna module includes an L1 band antenna and an L5 band antenna, both of which are fixed to the PCB substrate.

[0018] This application also provides a vehicle-mounted antenna, which includes a housing and a high-isolation vehicle-mounted 5G antenna structure as described in any of the above embodiments, wherein the high-isolation vehicle-mounted 5G antenna structure is disposed within a device receiving cavity opened in the housing.

[0019] Compared with the prior art, this disclosure has at least the following advantages:

[0020] The aforementioned high-isolation vehicle-mounted 5G antenna structure, by setting up a ground isolation area, a first current-blocking ground structure, and a second current-blocking ground structure, effectively blocks stray surface currents between different antennas. On the one hand, the ground isolation area cuts off the direct conduction path of stray surface currents. On the other hand, the first and second current-blocking ground structures break the uniform distribution of surface currents and generate impedance loss. The combined effect of these two structures effectively blocks stray surface currents between different antennas, reduces signal crosstalk between antennas, and improves the isolation between antennas, thereby ensuring the overall communication performance and operational stability of the high-isolation vehicle-mounted 5G antenna structure. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this disclosure and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A schematic diagram of a high-isolation vehicle-mounted 5G antenna structure according to an embodiment;

[0023] Figure 2 for Figure 1 Another schematic diagram of the high-isolation vehicle-mounted 5G antenna structure shown;

[0024] Figure 3 for Figure 1 The diagram shows the structure of the PCB substrate.

[0025] Figure 4 This is a diagram showing the isolation between the 5G full-band main antenna and the 5G full-band diversity antenna.

[0026] Figure 5 This is a diagram showing the isolation between the 5G full-band main antenna and the first MIMO PIFA antenna.

[0027] Figure 6 This is a diagram showing the isolation between the main antenna and the second MIMO PIFA antenna in the 5G full-band spectrum.

[0028] Figure 7The diagram shows the isolation data between the 5G full-band diversity antenna and the first MIMO PIFA antenna.

[0029] Figure 8 This is a diagram showing the isolation data between the 5G full-band diversity antenna and the second MIMO PIFA antenna.

[0030] Figure 9 This is a diagram showing the isolation data between the first MIMO PIFA antenna and the second MIMO PIFA antenna.

[0031] Figure 10 A graph showing the radiation capability data of the Thetaθ60-105° main antenna for the 5G full-band spectrum;

[0032] Figure 11 A graph showing the radiation capability data of a 5G full-band diversity antenna at Thetaθ60-105°.

[0033] Figure 12 A graph showing the radiation capability data of the first MIMO PIFA antenna at Thetaθ60-105°.

[0034] Figure 13 A graph showing the radiation capability data of the second MIMO PIFA antenna at Thetaθ60-105°.

[0035] Figure 14 A graph showing the voltage standing wave ratio (VSWR) of the main antenna across all 5G frequency bands;

[0036] Figure 15 A graph showing the voltage standing wave ratio (VSWR) of a 5G full-band diversity antenna;

[0037] Figure 16 The voltage standing wave ratio (VSWR) data for the first MIMO PIFA antenna is shown in the graph.

[0038] Figure 17 This is a graph showing the voltage standing wave ratio (VSWR) of the second MIMO PIFA antenna. Detailed Implementation

[0039] To facilitate understanding of this disclosure, a more complete description will be given below with reference to the accompanying drawings, which illustrate preferred embodiments of the present disclosure. However, this disclosure can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to enable a more thorough and complete understanding of the disclosure.

[0040] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0042] To better understand the technical solutions and beneficial effects of this disclosure, the following detailed description is provided in conjunction with specific embodiments:

[0043] like Figures 1 to 3 As shown, a high-isolation vehicle-mounted 5G antenna structure 10 according to an embodiment of the present disclosure includes a PCB substrate 100, a GNSS antenna module 200 disposed on the PCB substrate 100, at least one 5G full-band main antenna 300, at least one 5G full-band diversity antenna 400, and at least two 5G MIMO antennas 500. At least one ground isolation region 110 is disposed on the PCB substrate 100. The ground isolation region 110 is disposed between any two adjacent 5G full-band main antennas 300 and 5G full-band diversity antennas 400, and / or, the ground isolation region 110 is disposed between any two adjacent 5G MIMO antennas 500.

[0044] The PCB substrate 100 is also provided with at least one first current-blocking ground structure 120 and at least one second current-blocking ground structure 130. Each first current-blocking ground structure 120 is disposed near the feed end of a 5G full-band main antenna 300, and each second current-blocking ground structure 130 is disposed near the feed end of a 5G full-band diversity antenna 400.

[0045] The feed terminals of each 5G full-band main antenna 300, each 5G full-band diversity antenna 400 and each 5G MIMO antenna 500 are electrically connected to a connector 600. The GNSS antenna module 200 is fixed on the side of the PCB substrate 100 away from the ground isolation area 110 and is electrically connected to a connector 600.

[0046] In this embodiment, when the high-isolation vehicle-mounted 5G antenna structure 10 is in operation, each antenna module transmits and receives signals according to a preset frequency band. During the process of the antenna receiving or transmitting signals, surface currents are generated on the surface of the PCB substrate 100 based on the principle of electromagnetic induction. These surface currents flow on the metal layer of the PCB substrate 100. If not suppressed, they will directly form electromagnetic coupling between adjacent antennas, leading to mutual interference between antennas and thus reducing the antenna's radiation performance and signal sensitivity. At this time, since the ground isolation area 110 is set between the adjacent 5G full-band main antenna 300 and 5G full-band diversity antenna 400, or between two adjacent 5G MIMO antennas 500, and with the help of its grounding characteristics, most of the stray surface current can be guided to the ground end, thereby blocking the direct propagation of surface current between adjacent antennas, effectively suppressing the disorderly diffusion of surface current, and reducing electromagnetic coupling between antennas; secondly, the first current-blocking grounding structure 120 adjacent to the feed end of the 5G full-band main antenna 300 and the second current-blocking grounding structure 130 adjacent to the feed end of the 5G full-band diversity antenna 400 adopt an irregular grounding structure design. When the surface current is conducted in this irregular structure, additional impedance loss will be generated due to path bending and cross-sectional changes. By breaking the uniform distribution law of current in the traditional regular ground plane, the natural conduction trajectory of surface current is changed, which can further accurately suppress the strong surface current near the antenna feed end, thereby preventing the surface current from spreading to other antennas and further improving the isolation between antennas.

[0047] The aforementioned high-isolation vehicle-mounted 5G antenna structure 10, by setting a ground isolation area 110, a first current-blocking ground structure 120, and a second current-blocking ground structure 130, effectively blocks stray surface currents between different antennas, reduces signal crosstalk between antennas, and improves the isolation between antennas, thereby ensuring the overall communication performance and operational stability of the high-isolation vehicle-mounted 5G antenna structure 10.

[0048] like Figures 1 to 3As shown, in one embodiment, the 5G full-band main antenna 300 is a monopole main antenna, and the 5G full-band diversity antenna 400 is a monopole diversity antenna. The 5G full-band main antenna 300 and the 5G full-band diversity antenna 400 are respectively vertically fixed to the two long sides of the PCB substrate 100. In this embodiment, when the monopole antenna is working, stray surface currents are generated on the surface of the PCB substrate based on the principle of electromagnetic induction. These currents interfere with the radiation field distribution and impedance matching of the antenna through electromagnetic coupling, thereby affecting its communication performance. The first current-blocking grounding structure 120 is located near the feed end of the 5G full-band main antenna 300, and the second current-blocking grounding structure 130 is located near the feed end of the 5G full-band diversity antenna 400. These two structures form a clever combination with the monopole antenna. When the surface current flows on the PCB substrate, due to the irregular structure of the first current-blocking grounding structure 120 and the second current-blocking grounding structure 130, the path of the surface current is bent and the cross-section changes during conduction. According to electromagnetic principles, changes in current path and cross-section induce additional impedance loss, effectively weakening strong surface currents that might otherwise be directly coupled to the feed end of a monopole antenna. Specifically, for the 5G full-band main antenna 300, the first current-blocking grounding structure 120 precisely suppresses surface currents near its feed end. When the surface current approaches the feed end, it encounters the irregular path of the first current-blocking grounding structure 120, disrupting the originally uniform current distribution. It no longer flows in a straight line to the feed point; some current is directly guided to the ground end, while the remaining current is attenuated due to impedance loss caused by path bends and cross-section changes. This reduces stray currents affecting the feed end through electromagnetic coupling, lowering interference to the main antenna's signal reception and transmission. Similarly, the second current-blocking grounding structure 130 provides the same protection for the 5G full-band diversity antenna 400, ensuring stable operation and improving the overall signal purity and reliability of the antenna.

[0049] like Figures 1 to 3As shown, in one embodiment, the two 5G MIMO antennas 500 are a first MIMO PIFA antenna 510 and a second MIMO PIFA antenna 520. The first MIMO PIFA antenna 510 and the second MIMO PIFA antenna 520 are vertically fixed to the two long sides of the PCB substrate 100, and are offset from the 5G full-band main antenna 300 and the 5G full-band diversity antenna 400. In this embodiment, because the first MIMO PIFA antenna 510 and the second MIMO PIFA antenna 520 are vertically fixed to the two long sides of the PCB substrate 100 and offset from the main / diversity antennas, the omnidirectional radiation characteristics of the PIFA antenna itself, combined with the vertical polarization formed by vertical installation, create a rotationally symmetrical uniform radiation pattern in the horizontal direction. Specifically, in a vehicle environment, vehicles encounter signal sources from various directions and angles during operation. The vertical polarization characteristics of the PIFA antenna can reduce signal distortion caused by multipath reflection, ensuring comprehensive signal coverage and transmission stability. For example, in complex urban streets, surrounding buildings reflect and scatter signals. Vertically polarized antennas have a higher polarization matching degree with these reflected signals, reducing signal distortion caused by multipath superposition and lowering the risk of signal loss. Simultaneously, this vertical polarization characteristic also reduces the reception of horizontally polarized interference signals, mitigating the impact of external interference on antenna performance and further improving signal purity and reliability. Furthermore, the staggered arrangement of the first MIMOPIFA antenna 510, the second MIMOPIFA antenna 520, and the main / diversity antennas extends the physical distance between adjacent antennas and the stray surface current conduction path. Combined with the low coupling characteristics of vertical polarization, this effectively reduces electromagnetic coupling between the MIMO antennas and the main / diversity antennas, further enhancing the overall isolation of the antenna system.

[0050] like Figures 1 to 3As shown, in one embodiment, the second MIMO PIFA antenna 520 is provided with a ground coupling stub. In this embodiment, the ground coupling stub can precisely control the current distribution of the second MIMO PIFA antenna 520. Specifically, when the antenna transmits a signal, the ground coupling stub guides the current to flow along an optimized specific path, enabling the antenna to more efficiently convert electrical energy into electromagnetic waves for radiation. By optimizing the current distribution, the ground coupling stub improves the antenna's radiation efficiency in a specific frequency band, enhancing the effective radiation energy at the same transmission power and indirectly expanding the effective signal coverage. Furthermore, the ground coupling stub can suppress stray current interference on the antenna current distribution in the vehicle environment, ensuring the stable performance of the omnidirectional radiation characteristics of the PIFA antenna, reducing radiation dead zones caused by current distribution, reducing multipath signal distortion, and improving the reliability of signal transmission. When receiving signals, the ground coupling stub improves impedance matching characteristics by optimizing the antenna current distribution, indirectly enhancing the antenna's receiving sensitivity and enabling the antenna to more efficiently capture signals from different directions. Especially in vehicle scenarios, vehicles encounter various external interference sources during operation. The ground coupling stub reduces signal distortion caused by external interference by suppressing the influence of stray current on the antenna current distribution, thereby ensuring the quality of received signals.

[0051] like Figures 1 to 3 As shown, in one embodiment, the first current-blocking grounding structure 120 is a T-shaped structure. In this embodiment, when surface current flows on the PCB substrate 100, the T-shaped first current-blocking grounding structure 120, due to its special shape, can accurately suppress the surface current near the feed end of the 5G full-band main antenna 300. The lateral branches of the T-shaped structure can effectively intercept surface currents in different directions, forcing the current to deviate from its original direction; while the longitudinal branches further guide these intercepted currents to flow towards the ground end. Compared with ordinary irregular grounding structures, the T-shaped structure can intercept and guide surface currents more efficiently, reducing the accumulation and disordered flow of current near the feed end. Specifically, when the 5G full-band main antenna 300 transmits signals, its feed end will generate a strong surface current. The T-shaped first current-blocking grounding structure 120 can guide most of the stray surface currents to the ground end, thereby reducing interference to other antennas and improving the signal purity of the antenna.

[0052] like Figures 1 to 3As shown, in one embodiment, the first current-blocking grounding structure 120 includes a horizontal stub 121 and a vertical stub 122. The horizontal stub 121 is perpendicular to the vertical stub 122. The length L1 of the horizontal stub 121 ranges from 3mm to 10mm, and the length L2 of the vertical stub 122 ranges from 5mm to 20mm. In this embodiment, when surface current flows on the PCB substrate 100 and approaches the feed end of the 5G full-band main antenna 300, the length L1 of the horizontal stub 121, set within the range of 3mm to 10mm, can effectively intercept surface current flowing from different directions. For stray currents attempting to flow to the feed end, the horizontal stub 121 changes their flow direction through impedance guidance, preventing stray currents from interfering with the impedance matching and signal transmission / reception of the feed end. The vertical stub 122 further enhances this suppression effect. Its length L2, within the range of 5mm to 20mm, provides a clear guiding direction for the current intercepted by the horizontal stub 121. The longitudinal stub 122 can work in conjunction with the transverse stub 121 to precisely guide the intercepted current to the grounding terminal, preventing stray surface current from accumulating near the feed terminal and spreading to other antennas, thereby significantly reducing interference to adjacent antennas, effectively controlling the surface current near the feed terminal, improving the purity of the antenna signal, and reducing noise and distortion during signal transmission.

[0053] In another embodiment, the measured value of L1 is 5.85 mm and the measured value of L2 is 11.07 mm.

[0054] like Figures 1 to 3 As shown, in one embodiment, the second current-blocking grounding structure 130 is a concave structure. In this embodiment, when the surface current approaches the concave structure, the flow path of the current is forced to change due to the special shape of the concave inner wall. The surface current, which might originally flow along a straight or relatively regular path, flows along the concave inner wall under the action of the concave structure, thereby increasing the conduction length of the surface current. According to the principles of electromagnetics, the current will generate energy loss during conduction due to the conductor's own resistance and path bending. An increase in conduction length means that the impedance loss will increase accordingly. Therefore, when the surface current flows in the concave structure, it will generate more impedance loss due to the extension of the path, causing the originally strong surface current to be significantly weakened before reaching the feed end. Specifically, when the 5G full-band diversity antenna 400 is working, in the signal receiving state, the concave structure of the second current-blocking grounding structure 130 can reduce the signal noise caused by stray surface current interference. The weakening of the surface current makes the signal at the feed end purer, and can more accurately capture weak signals from the outside, thereby improving the receiving sensitivity of the diversity antenna.

[0055] like Figures 1 to 3As shown, in one embodiment, the second current-blocking grounding structure 130 includes a first current-blocking stub 131 and a second current-blocking stub 132. The first current-blocking stub 131 and the second current-blocking stub 132 are arranged parallel to each other, and the distance D1 between the first current-blocking stub 131 and the second current-blocking stub 132 is 5mm to 15mm. In this embodiment, when the surface current flows on the PCB substrate 100 and approaches the feed terminal of the 5G full-band diversity antenna 400, the first current-blocking stub 131 obstructs part of the surface current, changing its original flow direction. After encountering the first current-blocking stub 131, the surface current will bypass along the edge of the stub, thereby increasing the current conduction path length. According to the electromagnetic principle, the bending and increased length of the current conduction path together bring additional impedance loss, causing the intensity of this part of the surface current to gradually weaken during the bypass process. Then, the surface current whose path has been changed by the first current-blocking stub 131 will be further affected by the second current-blocking stub 132. Since the first stub 131 and the second stub 132 are parallel to each other and the spacing D1 is set within the range of 5mm to 15mm, this spacing is neither too small, which would affect the suppression effect due to electromagnetic coupling between the two stubs, nor too large, which would prevent them from working effectively together. When the surface current enters this spacing region under the guidance of the first stub 131, the second stub 132 will intervene in the current path again, further forcing the surface current to change direction and making it flow more tortuously, thereby further increasing the current conduction path length and impedance loss. The synergistic effect of this concave structure composed of two stubs and lateral connecting stubs significantly weakens the originally strong surface current before it reaches the feed end. Compared with a single stub structure, the concave structure with two stubs working together can more comprehensively and thoroughly suppress the surface current and reduce its interference to the feed end, thereby improving the sensitivity of the received signal of the 5G full-band diversity antenna 400.

[0056] like Figures 1 to 3As shown, in one embodiment, the preferred low elevation gain of the high-isolation vehicle-mounted 5G antenna structure 10 corresponds to a zenith angle range of Theta 60° to 105°. In this embodiment, this zenith angle range corresponds to an elevation angle of -15° to 30°, with values ​​above the horizontal plane being positive and those below being negative. Within the θ 60° to 105° range, the high-isolation vehicle-mounted 5G antenna structure 10 can more effectively receive signals from low elevation directions during vehicle operation. For example, in urban environments with dense buildings, signals often reach the vehicle at a low elevation angle after multiple reflections and refractions. In this case, the high gain characteristic of the antenna within this low elevation angle range can enhance the reception capability of these reflected and refracted signals, reduce signal loss, and improve the integrity and accuracy of signal reception. In open areas such as suburbs or mountains, although the signal propagation path is relatively direct, there may still be situations where the signal propagates at a low elevation angle due to terrain undulations. The low elevation angle high gain characteristic of this antenna can also ensure stable signal reception and guarantee smooth communication between the vehicle and the outside world. In terms of signal transmission, the high gain characteristic of this low elevation angle direction helps the antenna radiate signals into the surrounding environment at a low elevation angle. In vehicular communication, vehicles need to exchange information with base stations, other vehicles, or roadside facilities. A low elevation angle transmission angle can improve signal coverage and propagation efficiency. This high gain characteristic of the low elevation angle direction allows the antenna to better cover the low elevation area around the vehicle, reducing signal blind spots and ensuring communication continuity and stability.

[0057] like Figures 1 to 3As shown, in one embodiment, the GNSS antenna module 200 includes an L1 band antenna and an L5 band antenna, both of which are fixed to the PCB substrate 100. In this embodiment, the L1 band antenna (center frequency 1575.42MHz) is mainly used to receive signals from traditional satellite navigation systems such as the Global Positioning System (GPS) and BeiDou-2. Its operating frequency band is widely used globally and has a mature technology system and multi-system satellite resource support. The L1 band antenna can stably capture signals from multiple satellites. After the acquired signals are processed by the multi-satellite positioning algorithm of the vehicle system, they provide basic positioning information for the vehicle system. The L5 band antenna (center frequency 1176.45MHz) is designed for high-precision applications of the next-generation satellite navigation system. The L5 band has a wider bandwidth and a better modulation method, which can provide more accurate positioning information than the single-frequency L1, with single-frequency positioning accuracy reaching sub-meter level. In complex environments such as urban canyons and areas with numerous high-rise buildings, the L1 band, due to its narrow bandwidth, has weak resistance to multipath interference. Its signal is easily affected by reflections and refractions from buildings, leading to decreased positioning accuracy and even positioning drift. In contrast, the L5 band antenna, with its wide bandwidth and modulation scheme adapted to next-generation satellite navigation systems, can effectively suppress multipath interference and reduce measurement errors caused by signal reflections and refractions. This allows it to provide stable sub-meter positioning services even in these complex scenarios, ensuring that vehicles accurately perceive their own position and surrounding environment while dynamically driving.

[0058] like Figures 1 to 3 As shown, in one embodiment, a fixing through hole 1001 is also provided on the PCB substrate 100. The fixing through hole 1001 is used to pass through a fastener to fix the PCB substrate 100 to the outer shell. In this embodiment, the fastener (such as screws, bolts, etc.) passes through the fixing through hole 1001 to firmly fix the PCB substrate 100 to the outer shell. During vehicle operation, the PCB substrate 100 and its components such as the antenna module and connector 600 are prone to loosening, displacement, or even damage due to vibration, which will affect the normal operation of the antenna. Since the PCB substrate 100 is stably fixed to the outer shell, this fixing method reduces the small displacement and deformation caused by vibration, thereby reducing the physical offset and electrical characteristic fluctuation of the signal transmission path caused by vibration; at the same time, the stable installation state can ensure that the signal is accurately transmitted along the preset path, reduce electromagnetic coupling interference and signal transmission errors caused by structural loosening, and further improve the signal transmission and reception performance of the entire antenna structure.

[0059] It should be noted that the isolation test data for the 5G full-band main antenna 300, the 5G full-band diversity antenna 400, the first MIMOPIFA antenna 510, and the second MIMOPIFA antenna 520 are as follows: Figures 4 to 9 As shown in the figure, the test frequency range covers 698MHz to 5GHz, including... Figure 4 As shown, the minimum isolation between the 5G full-band main antenna and the 5G full-band diversity antenna in the 1.452GHz and above frequency bands reaches -41.36dB (the larger the absolute value of the isolation, the smaller the interference between the antennas), indicating that the interference between the two is extremely small; Figure 5 As shown, the isolation between the 5G full-band main antenna 300 and the first MIMOPIFA antenna 510 is ≤-20dB (i.e., absolute value ≥20dB) across the entire test frequency band, indicating a high degree of isolation between them; similarly, from Figure 8 It can be seen that the isolation between the 5G full-band diversity antenna 400 and the second MIMOPIFA antenna 520 also meets the isolation test standard within the 698MHz~5GHz test frequency band. Combined with... Figures 4 to 9 According to the test data, the isolation of the core antenna combination in the 10 high-isolation vehicle-mounted 5G antenna structure can meet the industry test qualification standards.

[0060] On the other hand, the average gain test data of the 5G full-band main antenna 300, the 5G full-band diversity antenna 400, the first MIMOPIFA antenna 510, and the second MIMOPIFA antenna 520 in the range of θ60° to 105°, such as Figures 10 to 13 As shown, the test frequency covers 698MHz to 5GHz. In the test data of the four antennas, the average gain of all frequency points is not lower than the preset SPEC lower limit, indicating that the antenna radiation performance is stable in the core angle range of θ60° to 105° and can meet the signal coverage requirements in vehicle scenarios.

[0061] Furthermore, the voltage standing wave ratio (VSWR) data of the 5G full-band main antenna 300, the 5G full-band diversity antenna 400, the first MIMOPIFA antenna 510, and the second MIMOPIFA antenna 520 within the test frequency range of 698MHz to 5GHz are as follows: Figures 14 to 17 As shown in the figure, the voltage standing wave ratio (VSWR) of the four antennas meets the requirements for vehicle-mounted 5G antennas in the entire test frequency band from 698MHz to 5GHz, especially in the core 5G communication frequency band (700MHz to 3.7GHz).

[0062] This application also provides a vehicle-mounted antenna, which includes a housing and a high-isolation vehicle-mounted 5G antenna structure 10 according to any of the above embodiments. The high-isolation vehicle-mounted 5G antenna structure 10 is disposed within a device receiving cavity opened in the housing. In this embodiment, when the high-isolation vehicle-mounted 5G antenna structure 10 is put into operation, each antenna module performs signal transmission and reception according to a preset frequency band. During the process of the antenna receiving or transmitting signals, surface currents are generated on the surface of the PCB substrate 100 based on the principle of electromagnetic induction. These surface currents flow on the metal layer of the PCB substrate 100. If not suppressed, they will directly form electromagnetic coupling between adjacent antennas, resulting in mutual interference between antennas, thereby reducing the radiation performance and signal sensitivity of the antennas. At this time, since the ground isolation area 110 is set between the adjacent 5G full-band main antenna 300 and 5G full-band diversity antenna 400, or between two adjacent 5G MIMO antennas 500, and with the help of its grounding characteristics, most of the stray surface current can be guided to the ground end, thereby blocking the direct propagation of surface current between adjacent antennas, effectively suppressing the disorderly diffusion of surface current, and reducing electromagnetic coupling between antennas; secondly, the first current-blocking grounding structure 120 adjacent to the feed end of the 5G full-band main antenna 300 and the second current-blocking grounding structure 130 adjacent to the feed end of the 5G full-band diversity antenna 400 adopt an irregular grounding structure design. When the surface current is conducted in this irregular structure, additional impedance loss will be generated due to path bending and cross-sectional changes. By breaking the uniform distribution law of current in the traditional regular ground plane, the natural conduction trajectory of surface current is changed, which can further accurately suppress the strong surface current near the antenna feed end, thereby preventing the surface current from spreading to other antennas and further improving the isolation between antennas.

[0063] Compared with the prior art, this disclosure has at least the following advantages:

[0064] The aforementioned high-isolation vehicle-mounted 5G antenna structure 10, by setting a ground isolation area 110, a first current-blocking ground structure 120, and a second current-blocking ground structure 130, effectively blocks stray surface currents between different antennas, reduces signal crosstalk between antennas, and improves the isolation between antennas, thereby ensuring the overall communication performance and operational stability of the high-isolation vehicle-mounted 5G antenna structure 10.

[0065] The embodiments described above are merely illustrative of several implementations of this disclosure, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the disclosed patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this disclosure, and these all fall within the protection scope of this disclosure. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A high-isolation vehicle-mounted 5G antenna structure, comprising a PCB substrate, a GNSS antenna module disposed on the PCB substrate, at least one 5G full-band main antenna, at least one 5G full-band diversity antenna, and at least two 5G MIMO antennas, characterized in that, At least one ground isolation area is provided on the PCB substrate. The ground isolation area is located between any two adjacent 5G full-band main antennas and 5G full-band diversity antennas, and / or, the ground isolation area is located between any two adjacent 5G MIMO antennas. The PCB substrate is also provided with at least one first current-blocking grounding structure and at least one second current-blocking grounding structure. Each first current-blocking grounding structure is disposed adjacent to the feed end of the 5G full-band main antenna, and each second current-blocking grounding structure is disposed adjacent to the feed end of the 5G full-band diversity antenna. Each of the 5G full-band main antenna, each of the 5G full-band diversity antennas and each of the 5G MIMO antennas has its feed terminal electrically connected to a connector. The GNSS antenna module is fixed on the side of the PCB substrate away from the ground isolation area and is electrically connected to a connector.

2. The high isolation vehicle-mounted 5G antenna structure according to claim 1, characterized in that, The 5G full-band main antenna is a monopole main antenna, and the 5G full-band diversity antenna is a monopole diversity antenna. The 5G full-band main antenna and the 5G full-band diversity antenna are respectively vertically fixed to the two long sides of the PCB substrate.

3. The high isolation vehicle-mounted 5G antenna structure according to claim 2, characterized in that, The two 5G MIMO antennas are a first MIMO PIFA antenna and a second MIMO PIFA antenna. The first MIMO PIFA antenna and the second MIMO PIFA antenna are respectively vertically fixed to the two long sides of the PCB substrate and are offset from the 5G full-band main antenna and the 5G full-band diversity antenna.

4. The high isolation vehicle-mounted 5G antenna structure according to claim 3, characterized in that, The second MIMO PIFA antenna is equipped with a ground-coupled stub.

5. The high isolation vehicle-mounted 5G antenna structure according to claim 1, characterized in that, The first current-blocking grounding structure is a T-type structure.

6. The high isolation vehicle-mounted 5G antenna structure according to claim 5, characterized in that, The first current-blocking grounding structure includes horizontal branches and vertical branches. The horizontal branches are perpendicular to the vertical branches. The length of the horizontal branches ranges from 3mm to 10mm, and the length of the vertical branches ranges from 5mm to 20mm.

7. The high isolation vehicle-mounted 5G antenna structure according to claim 1, characterized in that, The second current-blocking grounding structure is a concave structure.

8. The high isolation vehicle-mounted 5G antenna structure according to claim 7, characterized in that, The second current-blocking grounding structure includes a first current-blocking branch and a second current-blocking branch. The first current-blocking branch and the second current-blocking branch are arranged parallel to each other, and the distance between the first current-blocking branch and the second current-blocking branch is 5mm to 15mm.

9. The high isolation vehicle-mounted 5G antenna structure according to claim 1, characterized in that, The GNSS antenna module includes an L1 band antenna and an L5 band antenna, both of which are fixed to the PCB substrate.

10. A vehicle-mounted antenna, characterized in that, The vehicle-mounted antenna includes a housing and the high-isolation vehicle-mounted 5G antenna structure as described in any one of claims 1 to 9, wherein the high-isolation vehicle-mounted 5G antenna structure is disposed within a device receiving cavity opened in the housing.

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