Ultra-wideband antenna structure and vehicle

Abstract

The invention relates to an ultra-wideband antenna structure and a vehicle, and belongs to the technical field of antennae, and the ultra-wideband antenna structure comprises a bearing unit which comprises an upper-layer dielectric substrate and a lower-layer dielectric substrate which are stacked; the radiation unit comprises an upper-layer radiation patch arranged on the upper surface of the upper-layer dielectric substrate; the transmission unit comprises a feeder line arranged on the lower-layer dielectric substrate and a feed sheet connected with the feeder line and the upper-layer radiation patch; the grounding unit comprises a first grounding sheet and a second grounding sheet, the first grounding sheet is arranged on the lower dielectric substrate, gaps are formed between the first grounding sheet and the two sides of the feeder line, and the second grounding sheet and the end of the feeder line are arranged in a spaced mode and extend to the two sides of the feeder line and the two sides of the feed sheet. The upper-layer radiation patch and the grounding piece form a non-coplanar layout, signal transition is realized through the feed piece, the second grounding piece is matched to prevent energy leakage, the Q value of the antenna is reduced, surface wave propagation is inhibited, the impedance matching characteristic is improved, and the antenna keeps high emission efficiency in a broadband range.

Description

Technical Field

[0001] This application relates to the field of antenna technology, and in particular to an ultra-wideband antenna structure and vehicle. Background Technology

[0002] Ultra-wideband (UWB) technology, with its advantages of high temporal resolution, strong penetration capability, and resistance to multipath interference, has become one of the key technologies for achieving centimeter-level precise positioning, showing broad application prospects in scenarios such as vehicle collision avoidance warning, automatic parking, and keyless entry. For example, a 7.5GHz bandwidth between 3.1GHz and 10.6GHz has been allocated to UWB wireless communication services, providing ample spectrum resources for in-vehicle UWB applications.

[0003] In related technologies, automotive ultra-wideband antennas commonly employ microstrip antenna structures, with stripline feeding being widely used due to its compact structure and ease of integration. A typical automotive ultra-wideband antenna is usually composed of a multi-layer printed circuit board (PCB), with the radiating patch and feeding structure integrated within the PCB layers to achieve better electromagnetic shielding and structural stability. In this type of structure, the radiating patch is coplanar with the ground plane, and vertical feeding is achieved through metal vias. The impedance matching between the feed line and the radiating patch mainly depends on adjustments to the via parameters and the patch shape.

[0004] However, the above structure has significant drawbacks: the metal via feeding method results in a noticeable impedance discontinuity between the feed line and the radiating patch, causing severe signal reflection and a high reflection coefficient in the 4GHz–7.5GHz frequency band, making it difficult to achieve good broadband characteristics. Simultaneously, the via structure increases the difficulty of PCB fabrication and the alignment accuracy requirements, leading to a decrease in production yield. Furthermore, the coplanar arrangement of the radiating patch and the ground plane results in a high antenna Q value, significant surface wave effect, and limited radiation efficiency, failing to meet the stringent requirements for high transmission efficiency in automotive ultra-wideband applications. Therefore, it is necessary to research and improve the above structure to provide an ultra-wideband antenna structure and vehicle, aiming to achieve a more practical purpose. Summary of the Invention

[0005] In view of the shortcomings or deficiencies mentioned in the background technology, the present application provides an ultra-wideband antenna structure and vehicle, which has the advantages of wide radiation bandwidth, high transmission efficiency, simple structure and easy implementation and production.

[0006] In a first aspect, embodiments of this application provide an ultra-wideband antenna structure, including: The carrier unit includes an upper dielectric substrate and a lower dielectric substrate stacked together. A radiation unit, comprising an upper radiation patch disposed on the upper surface of the upper dielectric substrate; The transmission unit includes a feed line disposed on the lower dielectric substrate and a feed plate connecting the feed line and the upper radiating patch. The grounding unit includes a first grounding plate disposed on the lower dielectric substrate and forming a gap with both sides of the feed line, and a second grounding plate disposed at a distance from the end of the feed line and extending to both sides of the feed line and the feed plate.

[0007] In a first aspect, in some embodiments, the second grounding plate includes an end grounding plate located between the upper dielectric substrate and the lower dielectric substrate and spaced apart from the end of the feed line, and lateral grounding plates connected to the end grounding plate and extending to both sides of the feed plate respectively.

[0008] In some embodiments, the end grounding plate is connected to a metal via that penetrates the upper dielectric substrate, and the upper radiating patch is provided with a through hole that avoids the metal via hole, as well as notches located on both sides of the through hole.

[0009] In one aspect, in some embodiments, the lateral grounding plate includes rectangular metal plates located on both sides of the feed line and the feed plate, and a first strip-shaped metal plate connecting the rectangular metal plates and the end grounding plate.

[0010] In some embodiments, the first strip-shaped metal sheet does not overlap with the upper radiating patch on the projection surface in the thickness direction of the upper dielectric substrate.

[0011] In one aspect, in some embodiments, the lateral grounding plate further includes a second strip-shaped metal plate connected to the rectangular metal plate and extending at one end toward the end grounding plate, the second strip-shaped metal plate being spaced apart from the end grounding plate and disposed close to the feed line side.

[0012] In a first aspect, in some embodiments, the first grounding piece includes two upper metal pieces disposed on the upper surface of the lower dielectric substrate and respectively located on both sides of the feed line, a lower metal piece disposed on the lower surface of the lower dielectric substrate, and a lateral metal piece connecting the upper metal pieces and the lower metal pieces.

[0013] In some embodiments, the feed sheet is a semi-cylindrical metal sheet, and the upper dielectric substrate has a through-hole semi-cylindrical mounting groove at its end for matching the semi-cylindrical metal sheet.

[0014] In some embodiments, the gap width formed between the second grounding plate and both sides of the feed line is greater than the gap width formed between the first grounding plate and both sides of the feed line.

[0015] Secondly, embodiments of this application provide a vehicle, including: The ultra-wideband antenna structure described in any of the above items.

[0016] The beneficial effects of the technical solution provided in this application include: This application provides an ultra-wideband antenna structure and vehicle. The carrier unit includes an upper dielectric substrate and a lower dielectric substrate stacked together; a radiating unit includes an upper radiating patch disposed on the upper surface of the upper dielectric substrate; a transmission unit includes a feed line disposed on the lower dielectric substrate and a feed plate connecting the feed line and the upper radiating patch; and a grounding unit includes a first grounding plate disposed on the lower dielectric substrate and forming a gap with both sides of the feed line, and a second grounding plate spaced apart from the end of the feed line and extending to both sides of the feed line and the feed plate.

[0017] Therefore, by raising the upper radiating patch and connecting it to the upper surface of the upper dielectric substrate, a non-coplanar layout is formed with the grounding patch on the lower dielectric substrate. Signal transition is achieved through the feed plate. The first grounding patch forms a coplanar waveguide structure with gaps on both sides of the feed line. The second grounding patch is spaced apart from the end of the feed line and extends to both sides of the feed line and the feed plate to prevent energy leakage, effectively reducing the antenna Q value and suppressing surface wave propagation, significantly improving impedance matching characteristics. This structure reduces signal reflection and energy loss, enabling the antenna to maintain high transmission efficiency over a wide frequency range. All patch structures can be manufactured using planar bonding technology, eliminating the need for complex drilling or interlayer alignment, greatly simplifying the manufacturing process, reducing production costs, and showing good prospects for engineering applications. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the antenna structure according to an embodiment of this application; Figure 2 This is an exploded view of the antenna structure according to an embodiment of this application; Figure 3 This is a schematic diagram of the upper radiating patch structure according to an embodiment of this application; Figure 4 This is a schematic diagram of the structure of the second grounding piece according to an embodiment of this application; Figure 5 This is a graph showing the relationship between the antenna reflection coefficient and frequency in an embodiment of this application; Figure 6 This is a graph showing the relationship between antenna standing wave ratio and frequency in an embodiment of this application; Figure 7 This is a graph showing the relationship between antenna input impedance and frequency in an embodiment of this application; Figure 8 This is a graph showing the relationship between the antenna excitation source impedance and frequency in an embodiment of this application. Figure 9 This is an E-plane gain diagram of the antenna in an embodiment of this application; Figure 10 This is an H-plane gain diagram of the antenna in an embodiment of this application; Figure 11 This is a three-dimensional far-field gain diagram of the antenna in an embodiment of this application.

[0020] The attached diagram lists the components represented by each number as follows: 1. Upper dielectric substrate; 2. Lower dielectric substrate; 3. Upper radiating patch; 31. Notch; 4. Feed line; 5. Feed plate; 6. First grounding plate; 61. Upper metal plate; 62. Lower metal plate; 63. Lateral metal plate; 7. Second grounding plate; 71. End grounding plate; 72. Lateral grounding plate; 721. Rectangular metal plate; 722. First strip metal plate; 723. Second strip metal plate; 8. Metal via. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] In view of the shortcomings or deficiencies mentioned in the background technology, the present application provides an ultra-wideband antenna structure and vehicle, which has the advantages of wide radiation bandwidth, high transmission efficiency, simple structure and easy implementation and production.

[0023] See Figures 1 to 4 As shown, the first aspect of this application provides an ultra-wideband antenna structure, including: The carrier unit includes an upper dielectric substrate 1 and a lower dielectric substrate 2 stacked together. The radiation unit includes an upper radiation patch 3 disposed on the upper surface of the upper dielectric substrate 1; The transmission unit includes a feed line 4 disposed on the lower dielectric substrate 2, and a feed piece 5 connecting the feed line 4 and the upper radiating patch 3. The grounding unit includes a first grounding plate 6 disposed on the lower dielectric substrate 2 and forming a gap with both sides of the feed line 4, and a second grounding plate 7 disposed at a distance from the end of the feed line 4 and extending to both sides of the feed line 4 and the feed plate 5.

[0024] The ultra-wideband antenna structure of this application embodiment effectively solves the technical problems of narrow bandwidth, low efficiency, and complex manufacturing process of traditional vehicle-mounted ultra-wideband antennas through a non-coplanar layout design. This structure raises the upper radiating patch 3 to form a non-coplanar layout with the grounding patch on the lower dielectric substrate 2, and achieves smooth signal transition through the feed plate 5, significantly reducing the antenna Q value and suppressing surface wave propagation.

[0025] The gaps formed by the first grounding plate 6 and the two sides of the feed line 4 constitute a coplanar waveguide structure. The second grounding plate 7 is spaced apart from the end of the feed line 4 and extends to both sides of the feed line 4 and the feed plate 5, together constructing a complete electromagnetic field confinement system, which greatly improves the impedance matching characteristics.

[0026] This design avoids the impedance discontinuity problem caused by traditional via feeding, reduces signal reflection and energy loss, and enables the antenna to maintain high transmission efficiency over a wide frequency range. All metal sheet structures are manufactured using a planar bonding process, eliminating the need for complex drilling or interlayer alignment, which greatly simplifies the manufacturing process, reduces production costs, and has promising prospects for engineering applications.

[0027] In specific implementation, both the first grounding plate 6 and the second grounding plate 7 are fixedly attached to the surface of the lower dielectric substrate 2, and the feed line 4 is fixedly attached to the upper surface of the lower dielectric substrate 2. The feed line 4 and the second grounding plate 7 are coplanar. The end of the feed line 4 away from the second grounding plate 7 forms a coplanar waveguide port with the first grounding plate 6, which is used to connect the coaxial feed line. The inner conductor of the coaxial feed line is connected to the feed line 4, and the outer conductor is connected to the first grounding plate 6 and the second grounding plate 7.

[0028] After the signal is input, it is transmitted along the feed line 4. The gaps formed between the two sides of the feed line 4 and the first grounding plate 6 effectively confine the signal energy in the coplanar waveguide structure and propagate forward. When the signal propagates to the area of ​​the feed line 4 near the end of the second grounding plate 7, the second grounding plate 7, which is spaced apart from the end of the feed line 4, is used to confine the electromagnetic field and prevent energy from leaking to the end of the feed line 4, and guides the energy to couple to the feed plate 5.

[0029] The feed plate 5 can use an arc-shaped metal sheet as a three-dimensional transition structure to smoothly transmit the signal received at its bottom end to the upper radiating patch 3 connected at its top, avoiding the impedance abrupt changes caused by traditional point connections. Ultimately, the signal energy is radiated into space in the form of electromagnetic waves, with the main radiation direction perpendicular to the upper surface of the upper radiating patch 3. For example, the radius of curvature of the arc-shaped metal sheet is 0.5-1.5 mm, the height is 0.8-1.2 mm, and the bottom diameter, matching the feed line width, is 1.0-1.5 mm.

[0030] The second grounding plate 7 is coplanar with the feed line 4, providing not only a reference ground for the feed structure but also a suppression path for potential surface waves, effectively preventing energy from propagating laterally along the dielectric substrate and ensuring that energy is concentrated in the main radiation direction. This fully planar bonding structure design gives the antenna excellent wideband characteristics and high radiation efficiency, while significantly simplifying the manufacturing process and improving product consistency and reliability.

[0031] Firstly, in some alternative embodiments: see Figures 1 to 4 As shown, this application embodiment provides an ultra-wideband antenna structure. The second grounding plate 7 of the ultra-wideband antenna structure includes an end grounding plate 71 located between the upper dielectric substrate 1 and the lower dielectric substrate 2 and spaced apart from the end of the feed line 4, and a lateral grounding plate 72 connected to the end grounding plate 71 and extending to both sides of the feed plate 5.

[0032] In this embodiment, the second grounding plate 7 includes an end grounding plate 71 fixed between the upper dielectric substrate 1 and the lower dielectric substrate 2 and spaced apart from the end of the feed line 4, and lateral grounding plates 72 integrally connected to the edge of the end grounding plate 71 and extending to both sides of the feed plate 5. The end grounding plate 71 and the lateral grounding plates 72 on both sides form a π-shaped structure and are coplanar with the feed line 4.

[0033] Feed line 4 is fixedly connected to the upper surface of the lower dielectric substrate 2, and its end extends between the upper dielectric substrate 1 and the lower dielectric substrate 2. The end grounding piece 71 is located near the end of feed line 4, maintaining a certain distance from feed line 4. It is not directly connected to feed line 4, but has a gap coupling with the end of feed line 4, which is used to control the electromagnetic field boundary conditions at the end of feed line 4.

[0034] The end grounding piece 71 ensures that the end area of ​​feeder 4 has a stable ground reference potential, effectively preventing unnecessary radiation caused by the end effect. It is equivalent to the "ground anchor" at the end of feeder 4. Although it does not transmit signals, it provides a stable electrical environment for the end of the signal path.

[0035] The lateral grounding plates 72 on both sides and the end of the feed line 4 in the middle form a ground-signal-ground (GSG) structure, which effectively confines the electromagnetic field in the gap between the feed line 4 and the grounding plates, preventing the signal energy on the feed line 4 from leaking to the circuit areas on both sides. At the same time, impedance matching can be achieved through the precisely designed gap width.

[0036] This π-shaped grounding structure, independent of the first grounding piece 6, allows energy to smoothly transition from the end of the feed line 4 to the feed piece 5 through a slot coupling mechanism. This avoids the impedance discontinuity caused by traditional via connections, significantly reduces signal reflection, and improves the wideband characteristics and radiation efficiency of the antenna.

[0037] Firstly, in some alternative embodiments: see Figures 1 to 4 As shown, this application embodiment provides an ultra-wideband antenna structure. The end grounding plate 71 of the ultra-wideband antenna structure is connected to a metal via 8 that penetrates the upper dielectric substrate 1. The upper radiating patch 3 is provided with a through hole to avoid the metal via 8 and a notch 31 located on both sides of the through hole.

[0038] In this embodiment, a metal via 8 perpendicularly penetrating the upper dielectric substrate 1 is fixedly connected to the end grounding plate 71. The upper radiating patch 3 has through holes to avoid the metal via 8 and notches 31 on both sides of the through holes. The top of the metal via 8 forms an open circuit on the surface of the upper dielectric substrate 1 and is not directly connected to the upper radiating patch 3. As a key component of the three-dimensional grounding network, it leads the ground potential of the end grounding plate 71 to the upper surface, constructing a grounded electromagnetic bandgap structure boundary at the end, effectively suppressing surface wave propagation within the dielectric layer and preventing lateral energy leakage.

[0039] The array of 8 metal vias forms a "grounding wall," confining the electromagnetic field to the patch's radiation area and forcing energy to radiate more concentratedly into space, thereby improving antenna gain and efficiency. The vias on the upper radiating patch 3 physically avoid the vias, preventing direct contact between the patch and the vias and ensuring the normal operation of the radiating element. The notches 31 on both sides of the vias introduce inductive loading by extending the current path at the patch edge, counteracting the parasitic capacitance effect introduced by the vias, achieving fine-tuning of impedance matching, and widening the antenna's impedance bandwidth.

[0040] Furthermore, the design of notch 31 reduces the disturbance to the surface current distribution of the patch caused by the presence of the grounding via (a metallic foreign object), reduces interference with the main radiation polarization, and helps maintain a low cross-polarization level and a stable radiation pattern. In summary, the combined design of vias, through-holes, and notch 31 achieves both surface wave suppression and grounding network construction, as well as fine tuning of the patch radiation performance. It is a key collaborative structure for achieving high efficiency, low loss, and good matching in multilayer broadband antennas.

[0041] Firstly, in some alternative embodiments: see Figures 1 to 4 As shown, this application embodiment provides an ultra-wideband antenna structure. The lateral grounding plate 72 of the ultra-wideband antenna structure includes a rectangular metal plate 721 located on both sides of the feed line 4 and the feed plate 5, and a first strip-shaped metal plate 722 connecting the rectangular metal plate 721 and the end grounding plate 71.

[0042] In this embodiment, the lateral grounding plate 72 includes a rectangular metal plate 721 located on both sides of the feed line 4 and the feed plate 5, and a first strip-shaped metal plate 722 integrally connecting the edge of the rectangular metal plate 721 and the edge of the end grounding plate 71. The rectangular metal plate 721 serves as the main grounding area, providing a stable low-impedance grounding plane, ensuring the potential consistency of the entire grounding system, and together with the feed line 4, forming a ground-signal-ground (GSG) coplanar waveguide structure.

[0043] The first strip-shaped metal piece 722 is thin and long, with its width much smaller than its length, connecting the rectangular metal piece 721 and the end grounding piece 71. In high-frequency operation, due to the skin effect and distributed inductance, the first strip-shaped metal piece 722 exhibits high impedance characteristics. For high-frequency signals, the first strip-shaped metal piece 722 forms a high-impedance path, effectively suppressing the conduction of high-frequency energy from the end grounding piece 71 to the rectangular metal piece 721, preventing radiated energy leakage through the grounding path. For DC or low-frequency signals, the first strip-shaped metal piece 722 exhibits low impedance characteristics, maintaining good conductivity and ensuring that the metal via 8 on the end grounding piece 71 has a stable ground potential reference.

[0044] The design of this application ingeniously achieves the function of "only grounding what should be grounded, and not letting the radiated energy leak out", which not only ensures the integrity of the grounding system, but also avoids unnecessary loss of high-frequency signals, and significantly improves the radiation efficiency and wideband performance of the antenna.

[0045] Firstly, in some alternative embodiments: see Figures 1 to 4 As shown, this application embodiment provides an ultra-wideband antenna structure in which the first strip metal sheet 722 does not overlap with the upper radiating patch 3 on the projection surface of the upper dielectric substrate 1 in the thickness direction.

[0046] In this embodiment, the first strip-shaped metal sheet 722 does not overlap with the upper radiating patch 3 on the projection surface along the thickness direction of the upper dielectric substrate 1. This spatial layout design achieves multiple technical advantages.

[0047] First, it effectively avoids the additional parasitic capacitance that may be introduced due to vertical overlap, preventing unnecessary electromagnetic coupling between the upper radiating patch 3 and the lower grounding network, and ensuring that the self-resonance characteristics of the radiating patch are not disturbed. Second, this avoidance design allows the first strip metal plate 722 to independently assume its grounding function as a connecting bridge, focusing on providing low-impedance DC and low-frequency paths for the end grounding plate 71 and the lateral metal arm, without generating a loading effect on the radiation field of the upper patch. Furthermore, the non-overlapping layout ensures the purity of the electromagnetic environment below the upper radiating patch 3, making its near-field distribution more ideal, which helps to maintain a low cross-polarization level and a stable radiation pattern.

[0048] Furthermore, this spatial relationship allows the first strip-shaped metal sheet 722 to work in conjunction with the via array, forming effective electromagnetic bandgap structural boundaries on both sides of the patch, jointly suppressing surface wave propagation without interfering with the operation of the main radiator. This design, through precise spatial isolation, effectively decouples the grounding and radiation functions, which is a key structural feature for improving the antenna's broadband characteristics and radiation efficiency.

[0049] Firstly, in some alternative embodiments: see Figures 1 to 4 As shown, this application embodiment provides an ultra-wideband antenna structure. The lateral grounding plate 72 of the ultra-wideband antenna structure also includes a second strip metal plate 723 connected to the rectangular metal plate 721 and extending one end toward the end grounding plate 71. The second strip metal plate 723 is spaced apart from the end grounding plate 71 and disposed near the feed line 4.

[0050] In this embodiment, the lateral grounding plate 72 further includes a second strip-shaped metal plate 723 integrally connected to the edge of the rectangular metal plate 721 and extending at one end toward the end grounding plate 71. The second strip-shaped metal plate 723 is spaced apart from the end grounding plate 71 and disposed near the feed line 4. The end of the second strip-shaped metal plate 723 is not directly connected to the end grounding plate 71, and a set distance is maintained between them.

[0051] By adjusting the length, width, and spacing of the second strip metal piece 723 with the end grounding piece 71, precise impedance changes can be introduced within the target frequency band to offset the parasitic reactance generated at the end or transition zone of the feeder 4, thereby achieving broadband matching.

[0052] Furthermore, the presence of the second strip metal plate 723 alters the local electric field distribution, guiding energy to transition more smoothly from feed line 4 to feed plate 5, reducing signal reflection. This design cleverly separates high-frequency functions from DC grounding functions, allowing the second strip metal plate 723 to focus on RF matching and adjustment, while the first strip metal plate 722 provides a low-frequency grounding path. Working together, they significantly improve the antenna's impedance bandwidth and radiation efficiency in the 4GHz–7.5GHz frequency band, while maintaining structural simplicity and manufacturing feasibility.

[0053] Firstly, in some alternative embodiments: see Figures 1 to 4 As shown, this application embodiment provides an ultra-wideband antenna structure. The first grounding piece 6 of the ultra-wideband antenna structure includes two upper metal pieces 61 disposed on the upper surface of the lower dielectric substrate 2 and respectively located on both sides of the feed line 4, a lower metal piece 62 disposed on the lower surface of the lower dielectric substrate 2, and a lateral metal piece 63 connecting the upper metal pieces 61 and the lower metal pieces 62.

[0054] In this embodiment, the first grounding piece 6 adopts a three-dimensional layered structure design, including two upper metal pieces 61 fixed on the upper surface of the lower dielectric substrate 2 and located on both sides of the feed line 4, a lower metal piece 62 fixed on the lower surface of the lower dielectric substrate 2, and a lateral metal piece 63 fixedly connecting the upper metal piece 61 and the lower metal piece 62.

[0055] Lateral metal plates 63 are fixed to the side of the lower dielectric substrate 2, and two upper metal plates 61 are coplanar with the feed line 4. Precisely designed gaps are formed between the upper metal plates 61 on both sides of the feed line 4 and the feed line 4, creating a coplanar waveguide transmission environment on the surface of the upper dielectric substrate 1. This effectively confines the signal energy within the gaps on both sides of the feed line 4 for forward propagation, achieving precise control of the transmission mode and broadband impedance matching.

[0056] The lower metal plate 62 serves as a complete reference ground plane, providing a stable zero-potential reference for the entire antenna system. At the same time, it is vertically connected to the upper metal plate 61 through the lateral metal plate 63, forming a continuous and closed three-dimensional grounding network. This greatly reduces the parasitic inductance of the grounding loop, ensures that high-frequency signals have a low-impedance return path, and significantly improves the radiation efficiency of the antenna.

[0057] The lateral metal sheet 63 extends vertically along the sidewall of the dielectric substrate, reliably connecting the upper metal sheet 61 and the lower metal sheet 62. This not only enhances the integrity and equipotentiality of the grounding system, but also constructs an electromagnetic shielding wall between the upper dielectric substrate 1 and the lower dielectric substrate 2, effectively suppressing lateral energy leakage and surface wave propagation between layers.

[0058] Furthermore, this three-dimensional enclosed grounding structure effectively shields the feeder 4 and its transmitted electromagnetic field within a coaxial environment composed of the upper metal plate 61, the lateral metal plate 63, and the lower metal plate 62. This not only prevents interference caused by the external radiation of the feeder 4's energy but also blocks crosstalk from external electromagnetic signals to the signals transmitted inside the feeder 4, significantly improving the antenna's anti-interference capability and signal fidelity, and providing a stable and reliable RF front-end solution for vehicle-mounted ultra-wideband communication systems.

[0059] Firstly, in some alternative embodiments: see Figures 1 to 4 As shown in the figure, this application embodiment provides an ultra-wideband antenna structure. The feed piece 5 of the ultra-wideband antenna structure is a semi-cylindrical metal sheet, and the upper dielectric substrate 1 has a semi-cylindrical mounting groove that runs vertically through the end and is used to match the semi-cylindrical metal sheet.

[0060] In this embodiment, the feed sheet 5 is a semi-cylindrical metal sheet. The upper dielectric substrate 1 has a semi-cylindrical mounting groove that runs vertically through the end and is used to match the semi-cylindrical metal sheet. The opening of the semi-cylindrical mounting groove faces the feed line 4 to ensure that the signal transmission path between the feed sheet 5 and the feed line 4 is optimized.

[0061] The semi-cylindrical metal sheet is precisely fitted and fixed within the semi-cylindrical mounting groove, forming a stable mechanical and electrical connection. Feeder 4 adopts a strip-shaped metal sheet structure, with the diameter of the semi-cylindrical metal sheet matching the width of feeder 4, ensuring the continuity of the signal transmission interface.

[0062] The semi-cylindrical metal sheet is perpendicular to the feed line 4 and the upper radiating patch 3, forming a three-dimensional transition structure. When current flows from the feed line 4 along its length to the semi-cylindrical metal sheet, its end forms an arc (bottom semicircle). The current is not concentrated at a single point, but is evenly distributed across the entire edge of the semicircle. This distribution characteristic allows the current to gradually and smoothly transition to other directions. After entering the semi-cylindrical surface, the current is distributed on the curved metal surface, simultaneously having components along the axial direction and the height direction, and its direction continuously changes with position.

[0063] When the current reaches the edge of the top semicircle of the semi-cylindrical surface, the situation is symmetrical to that at the bottom, and the current direction is the tangent direction at that point. At the very center of the top semicircle, the tangent direction is consistent with the current direction of the upper radiating patch 3; on both sides of the semicircle, the tangent direction gradually changes from the height direction to the in-plane direction. The current smoothly flows from each point on the top semicircle into the upper radiating patch, achieving a seamless transition from the planar feed line 4 to the three-dimensional radiator. This effectively avoids the impedance discontinuity caused by traditional point connections, significantly reduces signal reflection, and improves energy transmission efficiency.

[0064] Firstly, in some alternative embodiments: see Figures 1 to 4As shown, this application embodiment provides an ultra-wideband antenna structure in which the gap width formed between the second grounding plate 7 and both sides of the feed line 4 is greater than the gap width formed between the first grounding plate 6 and both sides of the feed line 4.

[0065] In this embodiment, the gap width formed by the rectangular metal piece 721 of the second grounding piece 7 and both sides of the feed line 4 is greater than the gap width formed by the first grounding piece 6 and both sides of the feed line 4. Since the gap width directly affects the characteristic impedance of the transmission line: when the gap is smaller (the signal line is closer to ground), the capacitance per unit length is larger, and the characteristic impedance is lower; when the gap is larger (the signal line is farther from ground), the capacitance per unit length is smaller, and the characteristic impedance is higher.

[0066] This application features a design that abruptly transitions from small to large gaps along the length of the feed line 4, forming an impedance transformation structure that effectively cancels out the reactance components introduced by the feed plate 5 and the upper radiating patch 3, thereby achieving good matching over a wider frequency range.

[0067] Specifically, the small gap region formed by the first grounding plate 6 and both sides of the feed line 4 tightly confines the electromagnetic field within the narrow gap between the signal line and the ground, resulting in more concentrated energy suitable for long-distance transmission without radiation loss. Conversely, the large gap region formed by the rectangular metal plate 721 and both sides of the feed line 4 makes the electromagnetic field distribution relatively "loose," allowing some field lines to extend into further space. Intentionally increasing the gap width near the semi-circular surface of the feed line allows the electromagnetic field to "spread out" in advance, preparing for a smooth transition of energy from the confined transmission mode (coplanar waveguide mode) to the radiation mode (pattern radiation mode), significantly reducing signal reflection in the transition region.

[0068] Furthermore, by precisely adjusting the width of the local slots, unwanted higher-order modes can be suppressed, preventing resonance at specific frequencies that could lead to gain reduction or pattern distortion. At the same time, the amplitude and phase of the current flowing through the feed plate 5 into the upper patch are balanced, ensuring the symmetry and stability of the radiation pattern, ultimately achieving wideband and high-efficiency antenna performance.

[0069] See Figures 1 to 4 As shown, a second aspect of this application provides a vehicle, including: The ultra-wideband antenna structure of any of the above embodiments.

[0070] The vehicle in this application embodiment adopts the ultra-wideband antenna structure of any of the above embodiments. The upper radiating metal patch is raised through a three-dimensional feeding transition structure, which increases the equivalent distance between the radiator and the reference ground and reduces the near-field energy storage density. At the same time, the electromagnetic bandgap structure formed by the π-shaped second grounding patch 7 and the metal via array 8 effectively suppresses the propagation of surface waves. The synergistic effect of the two significantly reduces the antenna Q value, realizes ultra-wideband impedance matching, and greatly expands the working bandwidth compared with traditional microstrip antennas. The use of a semi-cylindrical feed plate 5 as a vertical transition structure achieves a smooth transition from the planar feed line 4 to the upper patch, avoiding impedance discontinuities and parasitic parameters caused by traditional via feeds. Combined with the three-dimensional grounding network composed of the π-shaped grounding plate and the lateral metal plate 63, surface waves and back radiation are effectively suppressed, and energy is confined to the main radiation direction, which significantly improves the radiation efficiency of the antenna. By separating the upper radiating patch 3 from the feed network in the vertical direction, the radiation function and the feed function are effectively decoupled, reducing the interference of the feed structure on the radiation polarization. Combined with the grounding map fence formed on both sides of the patch by the via array, the electric field distribution on the radiation aperture is further purified, and the cross-polarization discrimination rate is significantly improved. The multilayer dielectric substrate stacked structure integrates the feed network, ground network and radiating element on different layers, realizing the miniaturization design of the antenna. The bottom coplanar waveguide port is easy to connect directly to external circuits or coaxial feed structures, and has good integration. The π-shaped second grounding plate 7 and the metal via array 8 effectively suppress surface waves and reduce parasitic radiation at the edge of the medium, keeping the radiation pattern of the antenna stable within the operating frequency band. The sidelobe and back lobe levels are low, and the pattern distortion is small. In summary, this application achieves excellent performance of ultra-wideband, high efficiency, and low cross-polarization while maintaining miniaturization, making it suitable for the broadband and integrated requirements of modern wireless communication systems.

[0071] In the embodiments of this application, such as Figures 1 to 4 As shown, the specific implementation of the ultra-wideband antenna structure is as follows: The upper radiating patch 3 is a metal sheet with a length of 8mm and a width of 5mm. A semi-circular area with a diameter of 1mm is removed from one end to match the connection of the feed patch 5. A U-shaped notch 31 is provided at the other end. The long side of the notch 31 is 3mm and the wide side is 1.5mm. It is used to adjust the current path and introduce inductive loading to optimize impedance matching.

[0072] The upper dielectric substrate 1 is a cuboid structure made of ceramic material, with dimensions of 8mm (length) × 6mm (width) × 1.23mm (height). It has a relative permittivity of 5.2 and a relative loss tangent of 0.01, providing a low-loss radiation environment. The lower dielectric substrate 2 is made of FR4 material, with dimensions of 23.6mm (length) × 13mm (width) × 0.8mm (height). It has a relative permittivity of 4.4 and a relative loss tangent of 0.02, providing a stable transmission environment for the power supply network.

[0073] The upper metal plate 61 measures 12.88 mm in length and 5.2 mm in width, while the lower metal plate 62 measures 13 mm in length and 12.88 mm in width. These serve as a complete reference ground plane to ensure the equipotentiality of the entire antenna system. The lateral metal plate 63, measuring 12.88 mm in length and 0.8 mm in width, is vertically fixed along the sidewall of the lower dielectric substrate 2, connecting the upper metal plate 61 and the lower metal plate 62 to form an electromagnetic shielding wall.

[0074] The feeder 4 measures 16.28 mm in length and 1 mm in width. The feeder plate 5 matches the width of the feeder 4 and electrically connects the feeder 4 to the upper radiating patch 3. The end grounding plate 71 of the second grounding plate 7 measures 13 mm in length and 2 mm in width. The rectangular metal plate 721 measures 2 mm in length and 1.5 mm in width. The first strip metal plate 722 measures 4 mm in length and 0.3 mm in width. The distance between the two first strip metal plates 722 is 5.4 mm. The second strip metal plate 723 measures 2.5 mm in length and 0.3 mm in width. The spacing between the first strip metal plate 722 and the second strip metal plate 723 on the same side is 0.3 mm.

[0075] Metal via 8 is centrally located on end grounding plate 71 and penetrates the upper dielectric substrate 1. Rectangular metal sheets 721 are symmetrically arranged on both sides of feed line 4. The distance between rectangular metal sheet 721 and upper metal sheet 61 is 1.4mm. Except for upper dielectric substrate 1 and lower dielectric substrate 2, other sheet components can be made of copper foil metal sheets with a thickness of 0.035mm or 0.07mm to facilitate the simulation test of antenna performance.

[0076] like Figure 5 As shown, the antenna's reflection coefficient is below -5dB in the 4GHz to 7.5GHz operating frequency band, indicating that the signal energy can be efficiently transmitted to the radiating element without significant reflection loss. Figure 6 The results show that within the same frequency band, the voltage standing wave ratio (VSWR) of the antenna remains stable below 2, meeting the impedance matching requirements of ultra-wideband antennas.

[0077] like Figure 5 As shown, the antenna reflection coefficient changes with increasing frequency. In the range of 4GHz to 7.5GHz, the reflection coefficient is basically below -5dB, which meets the requirements of ultra-wideband antennas.

[0078] like Figure 6 As shown, the antenna standing wave ratio (VSWR) changes with increasing frequency. In the range of 4 GHz to 7.5 GHz, the VSWR can be stabilized at around 2, which meets the requirements of ultra-wideband antennas.

[0079] like Figure 7 As shown, the antenna input impedance changes with increasing frequency. In the range of 4GHz to 7.5GHz, the input impedance is mostly below 40Ω, which meets the requirements of an ultra-wideband antenna.

[0080] like Figure 8 As shown, the impedance of the antenna excitation source is constant as the frequency increases. In the range of 4GHz to 7.5GHz, the impedance of the antenna excitation source is 50Ω, which meets the requirements of an ultra-wideband antenna.

[0081] Figure 9 This is the gain diagram of the antenna's E-plane (the plane formed by the electric field intensity vector and the electromagnetic wave propagation direction). Figure 10 This is the gain diagram of the antenna's H-plane (the plane formed by the magnetic field strength vector and the electromagnetic wave propagation direction). Figure 11 The three-dimensional far-field gain plot of the antenna, such as Figure 9 , 10 As shown, the far-field gain of the antenna in the E-plane and H-plane is figure-eight shaped, and the antenna is omnidirectional in both the horizontal and vertical directions.

[0082] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0083] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0084] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An ultra-wideband antenna structure, characterized in that, include: The carrier unit includes an upper dielectric substrate (1) and a lower dielectric substrate (2) stacked together. The radiation unit includes an upper radiation patch (3) disposed on the upper surface of the upper dielectric substrate (1). The transmission unit includes a feed line (4) disposed on the lower dielectric substrate (2) and a feed plate (5) connecting the feed line (4) and the upper radiating patch (3). The grounding unit includes a first grounding plate (6) disposed on the lower dielectric substrate (2) and forming a gap with both sides of the feed line (4), and a second grounding plate (7) spaced apart from the end of the feed line (4) and extending to both sides of the feed line (4) and the feed plate (5).

2. The ultra-wideband antenna structure as described in claim 1, characterized in that: The second grounding piece (7) includes an end grounding piece (71) located between the upper dielectric substrate (1) and the lower dielectric substrate (2) and spaced apart from the end of the feed line (4), and a lateral grounding piece (72) connected to the end grounding piece (71) and extending to both sides of the feed piece (5).

3. The ultra-wideband antenna structure as described in claim 2, characterized in that: The end grounding plate (71) is connected to a metal via (8) that penetrates the upper dielectric substrate (1). The upper radiating patch (3) is provided with a through hole that avoids the metal via (8) and notches (31) on both sides of the through hole.

4. The ultra-wideband antenna structure as described in claim 2, characterized in that: The lateral grounding plate (72) includes a rectangular metal plate (721) located on both sides of the feed line (4) and the feed plate (5), and a first strip metal plate (722) connecting the rectangular metal plate (721) and the end grounding plate (71).

5. The ultra-wideband antenna structure as described in claim 4, characterized in that: On the projection surface of the upper dielectric substrate (1) in the thickness direction, the first strip metal sheet (722) does not overlap with the upper radiating patch (3).

6. The ultra-wideband antenna structure as described in claim 4, characterized in that: The lateral grounding plate (72) further includes a second strip metal plate (723) connected to the rectangular metal plate (721) and extending at one end toward the end grounding plate (71). The second strip metal plate (723) is spaced apart from the end grounding plate (71) and disposed close to the side of the feed line (4).

7. The ultra-wideband antenna structure as described in claim 1 or 2, characterized in that: The first grounding piece (6) includes two upper metal pieces (61) disposed on the upper surface of the lower dielectric substrate (2) and respectively located on both sides of the feed line (4), a lower metal piece (62) disposed on the lower surface of the lower dielectric substrate (2), and a lateral metal piece (63) connecting the upper metal piece (61) and the lower metal piece (62).

8. The ultra-wideband antenna structure as described in claim 1, characterized in that: The feed plate (5) is a semi-cylindrical metal sheet, and the upper dielectric substrate (1) has a semi-cylindrical mounting groove that runs vertically through the end and is used to match the semi-cylindrical metal sheet.

9. The ultra-wideband antenna structure as described in claim 1, characterized in that: The gap width formed between the second grounding plate (7) and both sides of the feed line (4) is greater than the gap width formed between the first grounding plate (6) and both sides of the feed line (4).

10. A vehicle, characterized in that, include: The ultra-wideband antenna structure according to any one of claims 1 to 9.

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