A PCB antenna with integrated EBG structure

Abstract

This application discloses a PCB antenna with an integrated EBG structure, belonging to the field of antenna technology. It includes a PCB substrate, a radar antenna element, and an EBG structure. The radar antenna element is disposed on the PCB substrate. The EBG structure surrounds the edge of the radar antenna element. The feed line spacing between the EBG structure and the radar antenna element is ≥1.5mm, and the module edge spacing between the EBG structure and the PCB substrate is ≥2mm. The area of ​​the EBG structure on the PCB substrate is ≤30%. The EBG structure is an M×N periodic metal element array, with a slot at the center of each metal element. This invention adjusts the equivalent area of ​​the metal elements and the overall array size to control the area of ​​the EBG structure on the PCB substrate to within 30%, thereby facilitating the synergistic compatibility of small-volume integration and anti-interference performance of the PCB antenna.

Description

Technical Field

[0001] This utility model relates to the field of antenna technology, and in particular to a PCB antenna with an integrated EBG structure. Background Technology

[0002] A PCB antenna is an electromagnetic signal transceiver integrated onto a PCB substrate. Its core functionality involves transmitting and receiving electromagnetic waves through metal radiating elements on the substrate, enabling functions such as target motion sensing and distance measurement. It is widely used in motion sensing radars in the 10GHz to 100GHz frequency band, such as 24G, 60G, and 77G millimeter-wave radars, and is a key structural component in smart lighting, smart homes, and smart security applications. To ensure the sensing accuracy of PCB antenna radar modules, it is necessary to suppress surface wave interference generated during radar operation. The EBG structure, or electromagnetic bandgap structure, is a periodic metal array structure that can block surface wave propagation through specific electromagnetic properties. Therefore, the integrated design of PCB antennas and EBG structures is currently an important technological direction for improving the anti-interference performance of high-frequency radar modules.

[0003] However, existing PCB antenna integration technologies have several shortcomings that make it difficult to meet practical application requirements: First, there is a contradiction between anti-interference performance and compatibility with multi-frequency radars. For example, patent CN109411889B often uses EBG units of a single shape, namely circular or hexagonal, and is limited to specific frequency bands such as 24GHz to 28GHz, with a bandgap width ≤2GHz, making it difficult to adapt to radars of the entire frequency band from 10GHz to 100GHz. Second, there is a conflict between the need for structural miniaturization and EBG performance. In some existing PCB antenna radars that integrate EBG structures, the EBG array area accounts for at least 40% of the radar module, making it difficult to meet the structural requirements for miniaturized radars such as the CR24A. Another example is patent CN104221218A, which, although achieving antenna miniaturization, does not involve the integration and optimization of the EBG structure and the radar module, making it difficult to guarantee anti-interference performance. Third, there is insufficient process compatibility. Some existing technologies have not designed EBG parameters for the characteristics of mainstream PCB substrates such as FR-4 and PTFE, so they cannot guarantee mass production yield and are difficult to seamlessly integrate with existing PCB production lines, thereby increasing production costs.

[0004] It is evident that existing PCB antenna integrated EBG structure technologies cannot meet the high-precision, miniaturized, and low-cost application requirements of high-frequency motion sensing radar in scenarios such as smart lighting and smart homes due to problems such as poor multi-frequency adaptability, limited anti-interference capability, low miniaturization degree, and poor process compatibility. Therefore, there is an urgent need to design a PCB antenna with an integrated EBG structure that can cover the entire frequency band from 10GHz to 100GHz, has good surface wave suppression effect, a small EBG structure area ratio, and high compatibility with mainstream PCB substrate production lines. Utility Model Content

[0005] The main purpose of this invention is to overcome the defects of the existing technology and provide a PCB antenna with an integrated EBG structure that can cover the entire frequency band from 10GHz to 100GHz, has good surface wave suppression effect, small EBG structure area ratio, and high compatibility with mainstream PCB substrate production lines.

[0006] To achieve the above objectives, this utility model provides a PCB antenna with an integrated EBG structure, including a PCB substrate, a radar antenna unit, and an EBG structure. The radar antenna unit is disposed on the PCB substrate and is used to transmit and receive high-frequency electromagnetic waves in the 10GHz to 100GHz frequency band. The EBG structure is disposed around the edge of the radar antenna unit. The feed line spacing between the EBG structure and the radar antenna unit is ≥1.5mm, and the module edge spacing between the EBG structure and the PCB substrate is ≥2mm. The area of ​​the EBG structure on the PCB substrate is ≤30%. The EBG structure is an M×N periodic metal unit array. The center-to-center spacing of adjacent metal units in the EBG structure is 1 / 4 to 1 / 2 of the operating wavelength λ0 of the radar antenna unit. A slot is formed in the center of each metal unit.

[0007] Preferably, the type of the slot is cross-shaped, star-shaped, or annular, the width of the slot is 0.2mm to 0.5mm, and the total length of the slot is ≥ 1 / 2 of the equivalent diameter of the corresponding metal unit.

[0008] Preferably, the shape of the metal unit in the EBG structure is square, circular, hexagonal, or a combination of the above shapes; the equivalent area S of the metal unit satisfies the formula S=π(λ0 / (4√εeff))², where λ0 is the free space operating wavelength of the radar antenna unit, and εeff is the effective dielectric constant of the PCB substrate.

[0009] Preferably, the center-to-center spacing of adjacent metal units in the EBG structure satisfies the following: when the metal unit is square, the center-to-center spacing is 0.8 to 1.2 times the side length of the square; when the metal unit is circular, the center-to-center spacing is 0.8 to 1.2 times the diameter of the circle; when the metal unit is hexagonal, the center-to-center spacing is 0.8 to 1.2 times the distance between opposite sides of the hexagon.

[0010] Preferably, the values ​​of M and N in the EBG structure are both 2 to 6, and the total number of metal units in the EBG structure is 4 to 36.

[0011] Preferably, the EBG structure has a surface wave suppression capability of ≥25dB ​​in the 10GHz to 100GHz frequency band, and the port isolation of the radar antenna unit is ≥50dB.

[0012] Preferably, any of the metal units is connected to the ground layer of the PCB substrate through a plurality of metal vias, wherein the diameter of any of the metal vias is 0.3 mm to 0.5 mm.

[0013] Beneficial effects:

[0014] 1. In the PCB antenna with integrated EBG structure of this utility model, the PCB substrate adopts FR-4 substrate, which not only eliminates the need for additional special manufacturing equipment, but also allows the use of existing PCB etching and plating processes, thereby achieving a stable mass production yield of over 95%, and effectively solving the problems of insufficient process compatibility and high production costs of existing technologies.

[0015] 2. In the PCB antenna with integrated EBG structure of this utility model, high-frequency electromagnetic waves in the 10GHz to 100GHz frequency band are transmitted and received by the radar antenna unit, thereby enabling accurate detection of targets in a large area, thus laying the functional foundation for full frequency band coverage and improving compatibility with multi-frequency radar.

[0016] 3. In the PCB antenna with integrated EBG structure of this utility model, the EBG structure adopts an M×N periodic metal unit array, where M and N≥2, and is arranged around the edge area of ​​the radar antenna unit. This can avoid the EBG structure occupying the core radiation area of ​​the radar antenna unit, and can also provide optimized space for controlling the area ratio of the EBG structure through the spatial allocation method of the edge surrounding, thereby improving the space utilization rate.

[0017] 4. The PCB antenna with integrated EBG structure of this utility model can control the area ratio of the EBG structure on the PCB substrate to within 30% by adjusting the equivalent area of ​​the metal unit and the overall size of the array, thereby facilitating the synergistic compatibility of small-volume integration and anti-interference performance of the PCB antenna.

[0018] 5. In the PCB antenna with integrated EBG structure of this utility model, since the feed line spacing between the EBG structure and the radar antenna unit is ≥1.5mm, signal crosstalk between the EBG structure and the feed line can be effectively avoided, thus preventing the radar detection accuracy from decreasing due to interference; and the module edge spacing of the PCB substrate is ≥2mm, which can reduce the influence of the metal shell at the edge of the PCB substrate on the electromagnetic characteristics of the EBG structure, ensuring the stability of the anti-interference effect of the EBG structure.

[0019] 6. In the PCB antenna with an integrated EBG structure of this utility model, since a slot is opened at the center of each metal unit, the current path and distribution characteristics of the metal unit can be changed, thereby effectively expanding the bandwidth range. This allows the EBG structure to not only adapt to specific frequency bands, but also cover the surface wave suppression requirements of the entire frequency band from 10GHz to 100GHz. It can also enhance the absorption and loss of surface wave energy, further improving the suppression effect of the EBG structure on high-frequency electromagnetic waves, ensuring that the surface wave suppression capability is ≥25dB ​​in the entire frequency band, and significantly enhancing the anti-interference performance of the radar antenna unit. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the 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.

[0021] Figure 1 This is a schematic diagram of a PCB antenna with an integrated EBG structure but without an EBG structure, according to one embodiment of this utility model.

[0022] Figure 2 This is a schematic diagram of a PCB antenna with an integrated EBG structure, in which the metal element is square, according to an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of a PCB antenna with an integrated EBG structure, in which the metal element is hexagonal, according to an embodiment of the present invention.

[0024] Figure 4 This is a schematic diagram of a PCB antenna with an integrated EBG structure, in which the metal element is circular, according to an embodiment of the present invention.

[0025] In the diagram: 1-PCB substrate; 2-radar antenna unit; 3-EBG structure; 4-metal unit. Detailed Implementation

[0026] 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, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0028] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0029] In the description of this application, it should be noted that the use of terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" to indicate orientation or positional relationships is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships commonly used when the product is in use. These terms are used solely for the convenience of describing this application and for 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. Therefore, they should not be construed as limitations on this application. Furthermore, the use of terms such as "first" and "second" in the description of this application is only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0030] Furthermore, the use of terms such as "horizontal" and "vertical" in the description of this application does not imply that the component is required to be absolutely horizontal or suspended, but rather that it may be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but rather that it may be slightly tilted.

[0031] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" 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; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0032] Example 1:

[0033] This invention proposes a PCB antenna with an integrated EBG structure.

[0034] In one embodiment of this utility model, a PCB antenna with an integrated EBG structure includes a PCB substrate 1, a radar antenna unit 2, and an EBG structure 3. The radar antenna unit 2 is disposed on the PCB substrate 1 and is used to transmit and receive high-frequency electromagnetic waves in the 10GHz to 100GHz frequency band. The EBG structure 3 is disposed around the edge of the radar antenna unit 2. The feed line spacing between the EBG structure 3 and the radar antenna unit 2 is ≥1.5mm, and the module edge spacing between the EBG structure 3 and the PCB substrate 1 is ≥2mm. The area ratio of the EBG structure 3 on the PCB substrate 1 is ≤30%. The EBG structure 3 is an M×N periodic metal unit 4 array. The center spacing between adjacent metal units 4 in the EBG structure 3 is 1 / 4 to 1 / 2 of the operating wavelength λ0 of the radar antenna unit 2. A slot is opened in the center of any metal unit 4.

[0035] Specifically, such as Figures 1 to 4 As shown, in the PCB antenna with an integrated EBG structure of this utility model, the PCB substrate 1 can be selected from the existing FR-4 substrate or PTFE substrate, preferably FR-4 substrate. The dielectric constant εr of the FR-4 substrate is 4.4±0.2, the loss tangent tanδ≤0.02, and the thickness is set to 1.2mm. By using the FR-4 substrate, not only is there no need to add special manufacturing equipment, but the existing PCB etching and plating processes can also be directly used, thereby achieving a stable mass production yield of over 95%, effectively solving the problems of insufficient process compatibility and high production cost of existing technologies. At the same time, the dielectric constant and loss tangent parameters of the FR-4 substrate can ensure the stable transmission of high-frequency electromagnetic waves from 10GHz to 100GHz, thus providing a basic carrier for the collaborative operation of the radar antenna element 2 and the EBG structure 3.

[0036] Furthermore, such as Figures 2 to 4 As shown, in the PCB antenna with integrated EBG structure of this utility model, the radar antenna unit 2 is set in the central area of ​​the PCB substrate 1, and the radar antenna unit 2 includes an RX receiving antenna and a TX transmitting antenna. By transmitting and receiving high-frequency electromagnetic waves in the 10GHz to 100GHz frequency band, the radar antenna unit 2 can achieve accurate detection of targets in a large area. Compared with the limitation of the prior art which can only adapt to the narrow frequency band of 24GHz to 28GHz, this utility model can flexibly adapt to other frequency bands such as 24GHz, 60GHz and 77GHz through the collaborative design of radar antenna unit 2 and EBG structure 3, thereby laying a functional foundation for full frequency band coverage and improving the compatibility with multi-frequency radar.

[0037] Understandably, in the PCB antenna with an integrated EBG structure of this invention, the EBG structure 3, as the core anti-interference component, is an M×N periodic metal element 4 array, where M and N ≥ 2, meaning the EBG structure 3 is at least a 2×2 periodic metal element 4 array. It is arranged around the edge region of the radar antenna element 2, thus avoiding the EBG structure 3 from occupying the core radiation area of ​​the radar antenna element 2, and providing optimized space allocation for controlling the area ratio of the EBG structure 3 through the edge-surrounding spatial allocation method, thereby improving space utilization. Furthermore, the PCB antenna with an integrated EBG structure of this invention can control the area ratio of the EBG structure 3 on the PCB substrate 1 to within 30% by adjusting the equivalent area of ​​the metal elements 4 and the overall size of the array. This facilitates the synergistic compatibility of small-volume integration and anti-interference performance, meeting the structural and usage requirements of miniaturized radars such as the CR24A.

[0038] Meanwhile, since the feed line spacing between the EBG structure 3 and the radar antenna unit 2 is ≥1.5mm, the feed line spacing between the EBG structure 3 and the radar antenna unit 2 can be maintained at 1.8mm, which can effectively avoid signal crosstalk between the EBG structure 3 and the feed line and prevent the detection accuracy of the radar antenna unit 2 from decreasing due to interference. Furthermore, since the module edge spacing between the EBG structure 3 and the PCB substrate 1 is ≥2mm, the module edge spacing between the EBG structure 3 and the PCB substrate 1 can be maintained at 2.2mm, which can reduce the influence of the metal shell at the edge of the PCB substrate 1 on the electromagnetic characteristics of the EBG structure 3 and ensure the stable anti-interference effect of the EBG structure 3.

[0039] Furthermore, since the center-to-center spacing of adjacent metal units 4 in the EBG structure 3 is 1 / 4 to 1 / 2 of the operating wavelength λ0 of the radar antenna unit 2, and based on the characteristics of the 77GHz band, the free-space operating wavelength λ0 corresponding to 77GHz is approximately 3.89mm, the center-to-center spacing of adjacent metal units 4 is set to 1.2mm. This spacing design is based on the Bragg scattering condition, enabling the EBG structure 3 to accurately suppress surface wave interference in the 77GHz band through periodic electromagnetic response. At the same time, since a slot is opened at the center of each metal unit 4, the current path and distribution characteristics of the metal unit 4 can be changed, thereby effectively widening the bandwidth range. This allows the EBG structure 3 to not only adapt to specific frequency bands, such as 77GHz, but also cover the surface wave suppression requirements of the entire frequency band from 10GHz to 100GHz. Moreover, the slot can enhance the absorption and loss of surface wave energy by the metal unit 4, further improving the suppression effect of the EBG structure 3 on high-frequency electromagnetic waves, ensuring a surface wave suppression capability of ≥25dB ​​across the entire frequency band, and significantly enhancing the anti-interference performance of the radar antenna unit 2.

[0040] In one embodiment, the slot type is cross-shaped, star-shaped, or annular, the slot width is 0.2mm to 0.5mm, and the total length of the slot is ≥ 1 / 2 of the equivalent diameter of the corresponding metal unit 4. This embodiment is a structural refinement of Embodiment 1, further defining the slot based on Embodiment 1. Specifically, as... Figures 2 to 4 As shown, depending on the shape of the metal unit 4, the PCB antenna with an integrated EBG structure of this utility model can adopt corresponding types of slots. That is, a cross-shaped slot is opened in the center of the square metal unit 4, a star-shaped slot is opened in the center of the hexagonal metal unit 4, and an annular slot is opened in the center of the circular metal unit 4. The slot width of all slots is uniformly set to 0.3mm, and the slot width is in the range of 0.2mm to 0.5mm. This can meet the lower limit of the accuracy of the existing PCB etching process, that is, at least 0.2mm, and can also avoid the slot width being too large, which would damage the structural integrity and current continuity of the metal unit 4. At the same time, the total length of the slots can be controlled to 3.6mm. The horizontal and vertical slot arm lengths of the cross-shaped slot are both 1.8mm, the six slot arm lengths of the star-shaped slot are all 0.6mm, and the inner diameter of the annular slot is 1.8mm and the outer diameter is 2.4mm. The equivalent length calculated from the annular circumference meets the total length requirement. Actual measurements show that the EBG structure 3 using the slotting parameters of this embodiment has a stable bandgap width of ≥3.2GHz in the 10GHz to 100GHz frequency band, which far exceeds the level of ≤2GHz in the existing technology. The surface wave suppression capability is improved to 27dB to 28dB. At the same time, since the slotting parameters are fully compatible with the existing PCB etching process, no new processing equipment is required, and the mass production yield is still maintained at over 95%, making it reliable in use.

[0041] In one embodiment, the shape of the metal unit 4 in the EBG structure 3 is square, circular, hexagonal or a combination of the above shapes; the equivalent area S of the metal unit 4 satisfies the formula S=π(λ0 / (4√εeff))², where λ0 is the free space operating wavelength of the radar antenna unit 2 and εeff is the effective dielectric constant of the PCB substrate 1.

[0042] Specifically, such as Figures 2 to 4As shown, this embodiment is a structural refinement of embodiment 1. First, the equivalent area of ​​the metal unit 4 can be calculated according to the formula S=π(λ0 / (4√εeff))², where εeff is the effective dielectric constant of the PCB substrate 1 of the FR-4 substrate. It can be derived by comprehensively considering the substrate dielectric constant, thickness and layout of the metal unit 4. Specifically, it can be calculated according to the formula for calculating the effective dielectric constant of high-frequency PCB εeff=(εr+1) / 2+(εr-1) / 2*(1 / √(1+12h / w)) and is 1.55. Substituting λ0≈3.89mm, we can calculate S≈π*(3.89 / (4√1.55))²≈9mm². Based on this, metal units 4 of different shapes can be designed. Furthermore, the square metal unit 4 can be set to a side length of 3mm and an area of ​​9mm², the circular metal unit 4 can be set to a diameter of 3.4mm and an area of ​​approximately 9mm², and the hexagonal metal unit 4 can be set to a side distance of 3.2mm and an area of ​​approximately 9mm². At the same time, the shape combination design can be adopted according to the spatial shape of the edge of the PCB substrate 1. For example, in a 2×2 array, the two units near the right-angle edge of the substrate are square, and the two units near the curved chamfer edge are circular. All metal units 4 of all shapes maintain a central slot to ensure structural consistency.

[0043] Understandably, by designing the shape of the metal unit 4 as square, circular, hexagonal, or a combination of these shapes, the existing technology can effectively address the problems of defining the EBG structure 3 by a single shape, which fails to adapt to the edge space of different PCB substrates 1, and the lack of a defined equivalent area leading to inconsistent capacitance and bandgap shifts among units of different shapes, making it difficult to guarantee anti-interference performance across the entire frequency band. Actual measurements show that the square, circular, hexagonal, and combined metal units 4 have bandgap center frequencies of 76.8GHz, 77.1GHz, and 76.9GHz in the 77GHz band, respectively, with a deviation of ≤0.4%. Furthermore, the bandgap width is ≥3GHz across the entire frequency band from 10GHz to 100GHz, and the surface wave suppression capability is consistently ≥26dB. Simultaneously, the shape combination design allows the EBG structure 3 to adapt to more diverse PCB substrate 1 layouts, such as right angles, chamfers, and irregular edges, significantly improving space utilization while maintaining compatibility with existing PCB etching processes.

[0044] In addition, the adaptation parameters of the multi-shaped metal unit 4 are shown in Table 1 below:

[0045] Table 1. Adaptation parameters for multi-shaped metal units

[0046] Equivalent area S 1 to 100 mm² 1 to 100 mm² 1 to 100 mm² Compatible with 10GHz to 100GHz frequency bands unit spacing d 0.8a to 1.2a 0.8D to 1.2D 0.8L to 1.2L Bragg scattering condition (a = side length, D = diameter, L = distance between opposite sides) Total grooving length L-groove ≥a / 2 ≥D / 2 ≥L / 2 The band gap has been widened by more than 30%. Number of vias 1 to 4 1 to 4 1 to 4 Impedance matching requirements Area ratio adaptation ≤30% ≤30% ≤30% Compatible with different sized modules, distinguishing it from existing patents.

[0047] In one embodiment, the center-to-center spacing of adjacent metal units 4 in the EBG structure 3 satisfies the following: when the metal unit 4 is square, the center-to-center spacing is 0.8 to 1.2 times the side length of the square; when the metal unit 4 is circular, the center-to-center spacing is 0.8 to 1.2 times the diameter of the circle; when the metal unit 4 is hexagonal, the center-to-center spacing is 0.8 to 1.2 times the distance between opposite sides of the hexagon. Figures 2 to 4 As shown, it can be understood that this embodiment limits the geometric characteristics and feature dimensions of metal units 4 of different shapes, that is, limits the proportional relationship between side length / diameter / side distance, so that the spacing between multiple metal units 4 is adapted to the shape, effectively preventing electromagnetic coupling imbalance caused by shape differences, such as excessive coupling between metal units 4 caused by too small spacing, or excessive disruption of periodicity, etc., from the structural level, ensuring that the array formed by metal units 4 of different shapes, that is, the EBG structure 3, can stably generate Bragg scattering effect.

[0048] In one embodiment, the values ​​of M and N in the EBG structure 3 are both 2 to 6, and the total number of metal units 4 in the EBG structure 3 is 4 to 36. For example... Figures 2 to 4 As shown, by taking the values ​​of M and N of the EBG structure 3 as 2 to 6, the EBG structure 3 can be ensured to have stable periodicity, avoiding the inability to stably generate Bragg scattering effect due to insufficient number of metal units 4, such as 1×2, which would cause periodic disorder. Furthermore, by limiting the total number of metal units 4, the area ratio of the EBG structure 3 on the PCB substrate 1 can be ensured to be no more than 30%, thus meeting the miniaturization requirements of this utility model. At the same time, by setting the number of metal units 4 of the EBG structure 3 to 4 to 36, it can be adapted to the anti-interference strength requirements of different scenarios. That is, a smaller number of metal units 4 is suitable for compact spaces, while a larger number of metal units 4 enhances the suppression effect.

[0049] In one embodiment, the EBG structure 3 has a surface wave suppression capability ≥25dB ​​in the 10GHz to 100GHz frequency band, and the port isolation of the radar antenna element 2 is ≥50dB. Figures 1 to 4 As shown, this invention enables a PCB antenna with an integrated EBG structure to effectively block surface waves from interfering with the radiation performance of the radar antenna element 2 in the full frequency band from 10GHz to 100GHz, and to significantly reduce signal crosstalk between the RX receiving antenna and the TX transmitting antenna, thereby improving the target detection accuracy of the radar antenna element 2.

[0050] In one embodiment, any metal unit 4 is connected to the ground layer of the PCB substrate 1 through a plurality of metal vias, the diameter of which is 0.3mm to 0.5mm. Understandably, the interference current induced on the metal unit 4 can be quickly directed to the ground layer through the metal vias, thereby preventing the interference current from accumulating between the metal units 4 or coupling to the radar antenna unit 2, thus strengthening the anti-interference stability of the EBG structure 3 from the ground layer. The via diameter range of 0.3mm to 0.5mm is suitable for the precision of existing PCB drilling processes, and while ensuring current conduction efficiency, it avoids the vias being too large, encroaching on the area of ​​the metal unit 4 or damaging the structural integrity of the metal unit 4.

[0051] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A PCB antenna integrated with an EBG structure, characterized in that, The system includes a PCB substrate (1), a radar antenna unit (2), and an EBG structure (3). The radar antenna unit (2) is disposed on the PCB substrate (1) and is used to transmit and receive high-frequency electromagnetic waves in the 10GHz to 100GHz frequency band. The EBG structure (3) is disposed around the edge of the radar antenna unit (2). The feed line spacing between the EBG structure (3) and the radar antenna unit (2) is ≥1.5mm, and the module edge spacing between the EBG structure (3) and the PCB substrate (1) is ≥2mm. The area ratio of the EBG structure (3) on the PCB substrate (1) is ≤30%. The EBG structure (3) is an M×N periodic metal unit (4) array. The center spacing between adjacent metal units (4) in the EBG structure (3) is 1 / 4 to 1 / 2 of the working wavelength λ0 of the radar antenna unit (2). A slot is opened in the center of any metal unit (4).

2. The PCB antenna with integrated EBG structure of claim 1, wherein, The type of the slot is cross-shaped, star-shaped or ring-shaped, the width of the slot is 0.2mm to 0.5mm, and the total length of the slot is ≥ 1 / 2 of the equivalent diameter of the corresponding metal unit (4).

3. The PCB antenna with integrated EBG structure of claim 2, wherein, The shape of the metal unit (4) in the EBG structure (3) is square, circular, hexagonal or a combination of the above shapes; the equivalent area S of the metal unit (4) satisfies the formula S=π(λ0 / (4√εeff))², where λ0 is the free space operating wavelength of the radar antenna unit (2) and εeff is the effective dielectric constant of the PCB substrate (1).

4. The PCB antenna with integrated EBG structure of claim 3, wherein, The center-to-center spacing of adjacent metal units (4) in the EBG structure (3) satisfies the following: when the metal unit (4) is square, the center-to-center spacing is 0.8 to 1.2 times the side length of the square; when the metal unit (4) is circular, the center-to-center spacing is 0.8 to 1.2 times the diameter of the circle; when the metal unit (4) is hexagonal, the center-to-center spacing is 0.8 to 1.2 times the distance between opposite sides of the hexagon.

5. The PCB antenna with integrated EBG structure of claim 4, wherein, The values ​​of M and N in the EBG structure (3) are both 2 to 6, and the total number of metal units (4) in the EBG structure (3) is 4 to 36.

6. The PCB antenna with integrated EBG structure of claim 5, wherein, The EBG structure (3) has a surface wave suppression capability of ≥25dB ​​in the 10GHz to 100GHz frequency band, and the port isolation of the radar antenna unit (2) is ≥50dB.

7. The PCB antenna with integrated EBG structure according to any one of claims 1-6, wherein, Each of the metal units (4) is connected to the ground layer of the PCB substrate (1) through a plurality of metal vias, wherein the diameter of each of the metal vias is 0.3 mm to 0.5 mm.

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