A base station antenna

Abstract

The application discloses a base station antenna, and belongs to the technical field of communication equipment. The antenna comprises a first radiation layer, a first dielectric layer, a second radiation layer, a second dielectric layer and a PCB mainboard which are sequentially stacked from top to bottom; the first radiation layer is provided with a first feeding point and a second feeding point; the second radiation layer is provided with a third feeding point and a fourth feeding point; the first feeding point, the second feeding point, the third feeding point and the fourth feeding point are connected to a phase shift network on the PCB mainboard through metal columns which penetrate through the corresponding dielectric layers and metal layers. The base station antenna of the application adopts a laminated structure, is compact in structure, high in integration, simple in feeding and excellent in electrical performance, and is especially suitable for a Tianhong satellite communication system.

Description

Technical Field

[0001] This application relates to the field of communication equipment technology, and in particular to a base station antenna for a 5G signal base station. Background Technology

[0002] To compensate for the insufficient coverage of terrestrial networks, utilizing satellite communication systems to provide services such as wide-area coverage, emergency communication, and IoT data backhaul has become an important technological direction. In particular, the development of low-Earth orbit satellite constellations (such as Starlink and OneWeb) and geostationary orbit satellite communication systems (such as Tiantong and Inmarsat) in recent years has made direct communication between satellites and miniaturized ground base stations possible. Among them, Tiantong is a mobile communication satellite system independently constructed by my country, capable of providing voice, short message, and data services to handheld terminals, vehicle-mounted terminals, and miniaturized base stations.

[0003] However, in remote mountains and vast oceans, the construction of 5G signal base stations faces the problem of excessively high costs or even being impossible. Summary of the Invention

[0004] This application provides a base station antenna with a stacked structure, which is compact, highly integrated, has a simple power supply, and excellent electrical performance. It is particularly suitable for the Tiantong satellite communication system and is used to solve the above-mentioned technical problems.

[0005] This application proposes a base station antenna, comprising: a first radiating layer, a first dielectric layer, a second radiating layer, a second dielectric layer, and a PCB motherboard stacked sequentially from top to bottom; the first radiating layer has a first feed point and a second feed point; the second radiating layer has a third feed point and a fourth feed point; the first feed point, the second feed point, the third feed point, and the fourth feed point are respectively connected to a phase-shifting network on the PCB motherboard through metal pillars penetrating the corresponding dielectric layer and metal layer.

[0006] The base station antenna in this embodiment adopts a five-layer stacked structure (first radiating layer, first dielectric layer, second radiating layer, second dielectric layer, and PCB motherboard), integrating the transmitting and receiving antennas on the same vertical axis. This reduces the overall area and thickness of the antenna, which is beneficial for meeting the miniaturization and lightweight requirements of small base stations. The first and second radiating layers each have two feed points, which are directly connected to the phase-shifting network on the PCB motherboard via metal pillars. This eliminates the need for external power dividers and long-distance feed lines, reducing feed loss and parasitic parameters. All four feed points obtain feed signals from the PCB motherboard through vertical interconnection, avoiding parasitic radiation and additional losses introduced by horizontal traces. Furthermore, the second radiating layer serves as the ground for the first radiating layer (receiving antenna) while transmitting signals, achieving inter-layer functional multiplexing and eliminating the need for an additional grounding layer, further simplifying the structure.

[0007] In some embodiments, an annular groove is provided on the first dielectric layer and / or the second dielectric layer.

[0008] The embodiments of this application provide two benefits by setting an annular groove on the first dielectric layer and / or the second dielectric layer: First, the groove removes part of the dielectric material, thereby reducing the overall weight of the antenna and lowering material costs; Second, the presence of the annular groove changes the equivalent dielectric constant and local electromagnetic field distribution of the dielectric layer, thereby enabling slight adjustment of the resonant frequency of the first radiating layer and / or the second radiating layer to compensate for processing errors or adapt to different frequency band requirements, improving the design flexibility and yield of the antenna.

[0009] In some embodiments, the first dielectric layer has a first annular groove on the side facing the second radiating layer; and / or, the second dielectric layer has a second annular groove on the side facing the PCB motherboard.

[0010] In this embodiment, the first annular groove is specifically disposed on the side of the first dielectric layer facing the second radiating layer, and the second annular groove is disposed on the side of the second dielectric layer facing the PCB motherboard. This allows for independent adjustment of the resonant characteristics of the receiving and transmitting antennas, avoiding unnecessary electromagnetic coupling between the two annular grooves. Simultaneously, this split-side arrangement simplifies the groove fabrication (it can be formed in one step during dielectric layer injection molding or machining) and does not damage the metal integrity of the radiating layer surface, ensuring the antenna's radiation efficiency and long-term reliability. In some embodiments, a grounding hole is also included, which is disposed sequentially through the first radiating layer, the first dielectric layer, the second radiating layer, the second dielectric layer, and the PCB motherboard.

[0011] The grounding holes in this embodiment provide a unified reference potential for each layer, which helps stabilize the phase center of the antenna and improve the circular polarization axial ratio. The grounding holes can also serve as a positioning reference during assembly, ensuring the relative positional accuracy between the dielectric and radiating layers. Finally, the entire antenna stack structure can be mechanically fixed to the PCB motherboard via the grounding holes, eliminating the need for additional fasteners and simplifying the assembly process. Multiple grounding holes can also suppress interlayer parasitic modes and improve the antenna's isolation.

[0012] In some embodiments, the first radiating layer and the second radiating layer are metal layers; the first dielectric layer and the second dielectric layer are insulating dielectric layers; and the PCB motherboard is a printed circuit board.

[0013] In this embodiment, by using metal layers for the first and second radiating layers, good conductivity and radiation efficiency are ensured; the first and second dielectric layers are insulating dielectric layers, providing electrical isolation and mechanical support; and the PCB motherboard is a printed circuit board that can integrate a phase-shifting network, a feeder line, and a grounding layer. In some embodiments, the first dielectric layer is provided with a first dielectric via, the second radiating layer is provided with a first metal via, the second dielectric layer is provided with a third dielectric via, and the PCB motherboard is provided with a third metal via; it also includes a first metal pillar, the upper end of the first metal pillar being electrically connected to the first feed point, and the lower end of the first metal pillar passing through the first dielectric via, the first metal via, and the third dielectric via in sequence, and being electrically connected to the phase-shifting network on the PCB motherboard through the third metal via.

[0014] This embodiment of the application involves a first metal pillar perpendicularly passing through a first dielectric via, a first metal via, and a third dielectric via, ultimately extending to a third metal via on the PCB motherboard to connect to the phase-shifting network. This effectively shortens the transmission path of the receiving antenna's feed signal from the PCB motherboard to the first radiating layer, improving the smoothness of the transmission and reducing parasitic inductance and radiation loss introduced by horizontal traces. Furthermore, since the metal vias are located on different layers and aligned with each other, the alignment accuracy requirements in the multilayer board lamination process are clearly defined, which is beneficial for quality consistency during mass production.

[0015] In some embodiments, the first dielectric layer is provided with a second dielectric via, the second radiating layer is provided with a second metal via, the second dielectric layer is provided with a fourth dielectric via, and the PCB motherboard is provided with a fourth metal via; it also includes a second metal pillar, the upper end of the second metal pillar being electrically connected to the second feed point, and the lower end of the second metal pillar passing through the second dielectric via, the second metal via, and the fourth dielectric via in sequence, and being electrically connected to the phase-shifting network on the PCB motherboard through the fourth metal via.

[0016] In this embodiment, the second feed point is provided with an independent and complete vertical signal channel by having a second metal pillar pass sequentially through a second dielectric via on the first dielectric layer, a second metal via on the second radiating layer, and a fourth dielectric via on the second dielectric layer, and electrically connected to the phase-shifting network through a fourth metal via on the PCB motherboard. This ensures that the second feed point is physically separated from the first feed point, avoiding crosstalk between the two feed signals. This structural design allows the two feed signals to independently obtain the required feed amplitude and phase relationship from the phase-shifting network on the PCB motherboard, laying the structural foundation for achieving high-purity circularly polarized radiation.

[0017] In some embodiments, a fifth dielectric via is provided on the second dielectric layer, and a fifth metal via is provided on the PCB motherboard; it also includes a third metal pillar, the upper end of which is electrically connected to the third feed point, and the lower end of which passes through the fifth dielectric via and is electrically connected to the phase-shifting network on the PCB motherboard through the fifth metal via.

[0018] In this embodiment, the third feed point is electrically connected to the phase-shifting network on the PCB motherboard by passing a third metal pillar through a fifth dielectric via on the second dielectric layer. This design is simple, reduces the number of vias, and lowers insertion loss and parasitic parameters in the signal transmission path. As one of the two feed points of the transmitting antenna, the independent vertical channel of the third feed point effectively shortens the transmission path of the transmitted signal from the phase-shifting network on the PCB motherboard to the second radiating layer, and effectively reduces the interference experienced by the transmitted signal in the transmission path, which is beneficial for the transmitting antenna to obtain stable circular polarization excitation.

[0019] In some embodiments, a sixth dielectric via is provided on the second dielectric layer, and a sixth metal via is provided on the PCB motherboard; it also includes a fourth metal pillar, the upper end of which is electrically connected to the fourth feed point, and the lower end of which passes through the sixth dielectric via and is electrically connected to the phase-shifting network on the PCB motherboard through the sixth metal via.

[0020] In this embodiment, the fourth feed point is electrically connected to the phase-shifting network on the PCB motherboard by passing a fourth metal pillar through a sixth dielectric via on the second dielectric layer. This provides an independent and complete vertical signal channel for the fourth feed point, maintaining physical symmetry and separation from the third feed point, thus avoiding crosstalk between the two transmit feed signals. This structural design allows the third and fourth feed points to independently obtain the required feed amplitude and phase relationship from the phase-shifting network on the PCB motherboard, laying the structural foundation for the transmitting antenna to achieve high-purity circularly polarized radiation.

[0021] In some embodiments, the first radiating layer, the first dielectric layer, the second radiating layer, the second dielectric layer, and the PCB motherboard are circular plates with progressively increasing diameters.

[0022] In this embodiment, the first radiating layer, the first dielectric layer, the second radiating layer, the second dielectric layer, and the PCB motherboard are arranged as circular plates with progressively increasing diameters, forming a stepped stacked structure. This allows the larger lower layer (such as the PCB motherboard) to serve as a stable base, facilitating overall installation and heat dissipation. The second radiating layer has a larger diameter than the first radiating layer, providing sufficient ground plane for the receiving antenna and improving its gain and back lobe suppression. The dielectric layer has a slightly larger diameter than the corresponding radiating layer, protecting the edges of the radiating layer from mechanical damage and providing operating space for testing and soldering. The circular structure has rotational symmetry, which helps maintain the symmetry of circularly polarized radiation and is easy to process and assemble.

[0023] Additional aspects and advantages of the embodiments of this application will be described or shown in part in the following description, or illustrated by practice of the embodiments of this application. Attached Figure Description

[0024] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, which are not intended to limit the embodiments, and elements having the same reference numerals in the drawings are designated as similar elements.

[0025] Figure 1 This is a schematic diagram of the overall structure of the base station antenna in some embodiments of this application; Figure 2 This is a front view of the first radiating layer in some embodiments of this application; Figure 3 This is a front view of the first dielectric layer in some embodiments of this application; Figure 4 This is a structural diagram of the back side (side facing the second radiating layer) of the first dielectric layer in some embodiments of this application; Figure 5 This is a front view of the second radiating layer in some embodiments of this application; Figure 6 This is a front view of the second dielectric layer in some embodiments of this application; Figure 7 This is a structural diagram of the back side (side facing the PCB motherboard) of the second dielectric layer in some embodiments of this application; Figure 8 This is a front view of the PCB motherboard in some embodiments of this application; Figure 9 The following are simulation results of the reflection coefficient of the base station antenna in some embodiments of this application; Figure 10 The following are simulation results of the axial ratio of the base station antenna in some embodiments of this application; Figure 11 The following are simulation results of the left-hand rotational radiation efficiency of the base station antenna in some embodiments of this application; Figure 12 The following are simulation results of the left-hand maximum gain of the base station antenna in some embodiments of this application; Figure 13 The following are simulation results of the left-hand rotation gain of the base station antenna in the 1.99 GHz band in some embodiments of this application; Figure 14 The following is a simulation result of the left-hand gain of the base station antenna in the 2.19 GHz band in some embodiments of this application.

[0026] Explanation of annotations in the image: 110. First radiation layer; 111. First feed point; 112. Second feed point; 120. First dielectric layer; 121. First annular groove; 122. First dielectric hole; 123. Second dielectric hole; 130. Second radiation layer; 131. Third feed point; 132. Fourth feed point; 133. First metal aperture; 134. Second metal aperture; 140. Second dielectric layer; 141. Second annular groove; 142. Third dielectric hole; 143. Fourth dielectric hole; 144. Fifth dielectric hole; 145. Sixth dielectric hole; 150. PCB main board; 151. Third metal hole; 152. Fourth metal hole; 153. Fifth metal hole; 154. Sixth metal hole; 160. Grounding hole. Detailed Implementation

[0027] 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 described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.

[0028] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0029] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0030] In the description of the embodiments of this application, directional terms such as up, down, left, right, front, back, front, back, top, and bottom are defined relative to the structures shown in the accompanying drawings. The terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively. These are relative concepts and may therefore vary depending on their location and usage. Therefore, these or other directional terms should not be interpreted as restrictive terms.

[0031] The technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0032] Please see Figures 1 to 8This application provides a base station antenna with a five-layer stacked structure, comprising, from top to bottom, a first radiating layer 110, a first dielectric layer 120, a second radiating layer 130, a second dielectric layer 140, and a PCB motherboard 150. The first radiating layer 110 and the second radiating layer 130 are both conductive metal layers, preferably silver-plated copper sheets, with a silver plating thickness of not less than 2 μm to reduce high-frequency surface resistance. The first dielectric layer 120 and the second dielectric layer 140 are made of low-dielectric-loss insulating materials, such as PPO (polyphenylene oxide, dielectric constant approximately 2.65, loss tangent ≤ 0.003) or Rogers RO4350B (dielectric constant approximately 3.66, loss tangent 0.0037). The PCB motherboard 150 is a low-dielectric-loss high-frequency printed circuit board, which can employ a multilayer FR-4 and Rogers material hybrid structure. A first feed point 111 and a second feed point 112 are provided on the first radiating layer 110, and a third feed point 131 and a fourth feed point 132 are provided on the second radiating layer 130. The four feed points are electrically connected to the phase-shifting network on the PCB motherboard 150 after vertically penetrating the corresponding dielectric and metal layers through independent metal pillars. The metal pillars can be made of copper. The layers are laminated and fixed together under high temperature and pressure using prepreg or adhesive film to form an integrated antenna assembly.

[0033] Those skilled in the art can determine the specific dimensions of each radiating layer according to the target operating frequency band (such as the transceiver frequency band of Tiantong satellite) and the microstrip antenna design theory. For example, the diameter of the first radiating layer 110 can be set to 0.3-0.5 times the wavelength of the medium in the operating frequency band. The diameter of the second radiating layer 130 should be larger than that of the first radiating layer 110 to serve as a ground plane. The diameter of the PCB motherboard 150 should be larger than that of the second dielectric layer 140 to provide stable grounding and power supply network layout space.

[0034] In addition, the first feed point 111 and the second feed point 112 are at a 90° angle around the center of the first radiation layer 110. When the satellite circular polarization signal is received, the two feed points output induced signals with equal amplitude and a 90° phase difference. After being synthesized by the phase shifting network, the received signal is recovered, realizing circular polarization matching reception and improving the receiving sensitivity.

[0035] The third feed point 131 and the fourth feed point 132 are also at a 90° angle around the center of the second radiation layer 130. The third and fourth feed points 132 are set at a 90° angle. With the equal amplitude and 90° phase difference signal provided by the phase shifting network, a high-purity left-hand circularly polarized transmission wave can be generated on the second radiation layer 130 to ensure that the signal is stably received by the Tiantong satellite.

[0036] Furthermore, the first feed point 111 does not overlap vertically with either the third feed point 131 or the fourth feed point 132 below it, and the second feed point 112 does not overlap vertically with either the third feed point 131 or the fourth feed point 132, in order to reduce interlayer coupling, improve transmit / receive isolation, avoid the formation of parasitic resonance, reduce mutual interference of the feed network, and improve impedance matching.

[0037] In some embodiments, please refer to Figure 4 and Figure 7 The lower surface of the first dielectric layer 120 (i.e., the side facing the second radiation layer 130) is machined with an annular groove, namely the first annular groove 121, by mechanical milling or laser ablation. The depth of the first annular groove 121 can be 30%-50% of the thickness of the first dielectric layer 120, and the groove width is about one-third of the radius of the first dielectric layer 120. The lower surface of the second dielectric layer 140 (i.e., the side facing the second radiation layer 130) is also machined with an annular groove, namely the second annular groove 141, by mechanical milling or laser ablation. The depth of the second annular groove 141 can be 30%-50% of the thickness of the second dielectric layer 140, and the groove width is about one-quarter of the radius of the second dielectric layer 140. The center of the first annular groove 121 coincides with the center of the first dielectric layer 120, and the center of the second annular groove 141 coincides with the center of the second dielectric layer 140. The presence of the first annular groove 121 and the second annular groove 141 can reduce some dielectric material, thereby reducing the weight of the entire base station antenna by about 5%-10%. At the same time, the reduced equivalent dielectric constant of the groove region can cause the resonant frequency of the corresponding radiating layer to shift. By adjusting the depth and radius of the annular groove, the resonant frequency of the antenna can be finely adjusted by 20~60 MHz without changing the physical dimensions of the radiating layer, thereby compensating for manufacturing errors or adapting to different channel requirements.

[0038] In addition, the first annular groove 121 and the second annular groove 141 are also misaligned in the vertical direction (i.e., they do not overlap vertically) to avoid interlayer electromagnetic coupling, which is especially suitable for scenarios where antenna size is strictly limited and frequency fine-tuning is required.

[0039] In other embodiments, those skilled in the art may selectively provide the first annular groove 121 only in the first dielectric layer 120 or the second annular groove only in the second dielectric layer 140, depending on actual needs.

[0040] In some embodiments, a grounding hole 160 is also provided at the center of the entire base station antenna. The grounding hole 160 sequentially passes through the first radiating layer 110, the first dielectric layer 120, the second radiating layer 130, the second dielectric layer 140, and the PCB motherboard 150. The manufacturing process of the grounding hole 160 is as follows: after the layers are stacked and pressed together, a through hole is drilled, the inner wall of the hole is thickened by chemical copper plating and electroplating copper, and finally the hole wall is silver-plated; the grounding hole 160 is electrically connected to the ground plane of each radiating layer and the PCB motherboard 150.

[0041] Grounding hole 160 serves a triple purpose: First, it provides a stable RF reference ground, minimizing the phase center fluctuation of the antenna in the azimuth plane (measured to be less than 0.01 times the operating wavelength), thereby improving the circular polarization axial ratio; second, it serves as a calibration and positioning hole for interlayer assembly, allowing for alignment accuracy between layers (tolerance better than ±0.05mm) by inserting positioning pins during the pressing process; third, it mechanically secures the entire antenna stack to the PCB motherboard 150 without the need for additional fasteners, simplifying the assembly process. The aperture of grounding hole 160 can be conventionally optimized according to the antenna's mechanical strength requirements and electrical performance, for example, a aperture of 0.8-1.2 mm.

[0042] In some embodiments, the first radiating layer 110 and the second radiating layer 130 are metal layers; for example, both the first radiating layer 110 and the second radiating layer 130 can adopt a copper-based silver-plated disk structure; the first radiating layer 110 and the second radiating layer 130 can also adopt pure silver foil or silver-plated copper braided mesh to meet the needs of applications requiring higher conductivity. The first dielectric layer 120 and the second dielectric layer 140 are both insulating dielectric layers, and the materials can be low dielectric loss polymers, such as PPO (polyphenylene oxide), PTFE (polytetrafluoroethylene), cyanate resin or ceramic-filled composite dielectrics, with a dielectric constant between 2.2 and 3.7 and a loss tangent ≤ 0.004. The thickness of the first dielectric layer 120 and the second dielectric layer 140 can be determined according to the operating frequency band and mechanical strength. The PCB motherboard 150 is a printed circuit board, which can adopt a multilayer board structure, wherein the top layer where the phase-shifting network is located uses a low-loss material (such as Rogers 4000 series), and the remaining layers can use conventional FR-4 to balance cost and performance.

[0043] In some embodiments, please refer to Figures 2 to 8A first dielectric via 122 is provided on the first dielectric layer 120, a first metal via 133 is provided on the second radiating layer 130, a third dielectric via 142 is provided on the second dielectric layer 140, and a third metal via 151 is provided on the PCB motherboard 150. The upper end of a first metal pillar (copper pillar or silver-plated copper pillar) is electrically connected to the first feed point 111 (located on the upper surface of the first radiating layer 110) by reflow soldering or conductive adhesive bonding. The lower end of the first metal pillar passes downward through the first dielectric via 122, the first metal via 133, and the third dielectric via 142 in sequence, and then inserts into the third metal via 151 and is soldered to the inner wall of the via and an output pad of the phase-shifting network on the PCB motherboard 150. The diameter of the first metal pillar is smaller than the diameter of each via, and the gap between the first metal pillar and each via can be filled with solder or conductive adhesive to ensure reliable contact. The centers of the first dielectric via 122, the first metal via 133, the third dielectric via 142, and the third metal via 151 overlap vertically, with an allowable lamination offset of no more than ±0.05mm. In this embodiment, the first feed point 111 and the phase-shifting network on the PCB motherboard 150 are connected by a first metal pillar, which minimizes the signal transmission distance from the PCB motherboard 150 to the first radiating layer 110, eliminating the need for horizontal traces and avoiding the parasitic inductance and radiation loss introduced by traditional microstrip feed lines.

[0044] In some embodiments, please refer to Figures 2 to 8 A second dielectric via 123 is provided on the first dielectric layer 120, a second metal via 134 is provided on the second radiating layer 130, a fourth dielectric via 143 is provided on the second dielectric layer 140, and a fourth metal via 152 is provided on the PCB motherboard 150. The upper end of a second metal pillar (copper pillar or silver-plated copper pillar) is electrically connected to the second feed point 112 (located on the upper surface of the first radiating layer 110) by reflow soldering or conductive adhesive bonding. The lower end of the second metal pillar passes downward through the second dielectric via 123, the second metal via 134, and the fourth dielectric via 143 in sequence, and then inserts into the fourth metal via 152 and is soldered to the inner wall of the via and another output pad of the phase-shifting network on the PCB motherboard 150. The diameter of the second metal pillar is smaller than the diameter of each via, and the gap between the second metal pillar and each via can be filled with solder or conductive adhesive to ensure reliable contact. The centers of the second dielectric via 123, the second metal via 134, the fourth dielectric via 143, and the fourth metal via 152 overlap vertically, with an allowable lamination offset of no more than ±0.05mm. In this embodiment, the first feed point 111 and the phase-shifting network on the PCB motherboard 150 are connected by a first metal pillar, which minimizes the signal transmission distance from the PCB motherboard 150 to the first radiating layer 110, eliminating the need for horizontal traces and avoiding the parasitic inductance and radiation loss introduced by traditional microstrip feed lines.

[0045] The first feed point 111 and the second feed point 112 are typically positioned at a 90° angle on the first radiating layer 110 (e.g., around the center of the first radiating layer 110, located at 0° and 90° respectively along the circumferential direction), and the electrical lengths of the two vertical interconnect paths are equal—both pass through dielectric layers of the same thickness (first dielectric layer 120 + second dielectric layer 140) and the second radiating layer 130; this symmetrical design ensures that the two signals output from the phase-shifting network can reach the first and second feed points 112 with equal amplitude and a precise 90° phase difference, providing a structural guarantee for the receiving antenna to achieve high-purity circular polarization.

[0046] In some embodiments, please refer to Figures 6 to 8 The third feed point 131 is located on the upper surface of the second radiating layer 130. A fifth dielectric via 144 is opened on the second dielectric layer 140, and a fifth metal via 153 is opened on the PCB motherboard 150. The upper end of a third metal pillar (copper pillar or silver-plated copper pillar) is soldered to the third feed point 131, and then passes vertically downward through the fifth dielectric via 144. The lower end is inserted into the fifth metal via 153 and electrically connected to the phase shifting network (an output terminal of the transmitting part).

[0047] Unlike the feeding structure of the receiving antenna (first radiating layer 110), this path does not need to pass through the first dielectric layer 120 and the second radiating layer 130, because the third feed point 131 is itself located on the second radiating layer 130. The third metal pillar only needs to penetrate the second dielectric layer 140 to reach the PCB motherboard 150. This design makes the signal path of the third feed point 131 extremely short (approximately the thickness of the second dielectric layer 140) and results in lower insertion loss. The centers of the fifth dielectric via 144 and the fifth metal via 153 are vertically aligned, with the allowable alignment deviation controlled within ±0.05mm, to reduce unnecessary via layers, lower processing difficulty, and reduce failure rate.

[0048] In some embodiments, please refer to Figures 6 to 8 A sixth dielectric hole 145 is also opened on the second dielectric layer 140, and a sixth metal hole 154 is also opened on the PCB motherboard 150. The upper end of a fourth metal pillar is soldered to the fourth feed point 132, passes vertically downward through the sixth dielectric hole 145, and the lower end is inserted into the sixth metal hole 154 and electrically connected to the phase shifting network (another output end of the transmitting part). The length, diameter and material of the fourth metal pillar are the same as those of the third metal pillar.

[0049] The third feed point 131 and the fourth feed point 132 are positioned at a 90° angle on the second radiating layer 130 (e.g., around the center of the first radiating layer 110, located at 0° and 90° respectively along the circumferential direction). The sixth dielectric aperture 145 and the fifth dielectric aperture 144 are located on a circle of the same radius (also at a 90° angle). The two transmit feed signals experience the same transmission loss and phase change. This structural design ensures that the two excitation signals of the transmitting antenna (second radiating layer 130) have equal amplitude and a 90° phase difference, thereby obtaining high-purity left-hand circularly polarized radiation.

[0050] In some embodiments, please refer to Figure 1 The first radiating layer 110, the first dielectric layer 120, the second radiating layer 130, the second dielectric layer 140 and the PCB motherboard 150 are all circular boards with increasing diameters in sequence, forming a stepped stack. The increase in diameter of each layer can be determined according to actual design needs, but the following relative relationships should be met: the diameter of the first dielectric layer 120 is larger than the diameter of the first radiating layer 110, with an overhang of 2-10 mm on one side, to support the first radiating layer 110 and facilitate assembly; the diameter of the second radiating layer 130 is larger than the diameter of the first dielectric layer 120, with an overhang of 10-20 mm on one side, to serve as an effective flat surface for the receiving antenna and to accommodate the radiator of the transmitting antenna; the diameter of the second dielectric layer 140 is larger than the diameter of the second radiating layer 130, with an overhang of 5-15 mm on one side, to protect the edge of the second radiating layer 130 and provide isolation; the diameter of the PCB motherboard 150 is larger than the diameter of the second dielectric layer 140, with an overhang of 20-50 mm on one side, to provide sufficient ground plane, power supply network layout space and mechanical mounting area.

[0051] Meanwhile, the first radiating layer 110, the first dielectric layer 120, the second radiating layer 130, the second dielectric layer 140, and the PCB motherboard 150 are all circular boards. Their circular structure helps maintain the symmetry of the circularly polarized radiation pattern, and their stepped structure facilitates positioning during lamination by aligning the outer edges, eliminating the need for high-precision tooling. The protruding portion of the PCB motherboard 150 can also be used to mount auxiliary components such as RF connectors, positioning holes, and heat sinks to improve the antenna's electrical performance (e.g., gain, axial ratio, low elevation coverage) and mechanical reliability (vibration resistance, ease of assembly).

[0052] In addition, technicians have conducted a series of simulations on the base station antenna of any embodiment of this application.

[0053] Specifically, please refer to Figure 9For the third feed point 131 and the fourth feed point 132 corresponding to the high-frequency antenna element, the frequency band with a reflection coefficient better than -10 dB is 2.168 GHz to 2.203 GHz; for the first feed point 111 and the second feed point 112 corresponding to the low-frequency antenna element, the frequency band with a reflection coefficient better than -10 dB is 1.95 GHz to 2.02 GHz. This base station antenna has a good reflection coefficient.

[0054] Please see Figure 10 Within the high-frequency antenna element operating band of 2.17 GHz to 2.2 GHz, its axial ratio is less than 0.75 dB; within the low-frequency antenna element operating band of 1.98 GHz to 2.01 GHz, its axial ratio is less than 0.53 dB. This base station antenna has a good axial ratio.

[0055] Please see Figure 11 Within the high-frequency band of 2.17 GHz to 2.2 GHz, the average left-hand rotational radiation efficiency is 91.8%; within the low-frequency band of 1.98 GHz to 2.01 GHz, the average left-hand rotational radiation efficiency is 60.3%. This antenna exhibits high left-hand rotational radiation efficiency.

[0056] Please see Figure 12 Within the frequency band of 2.17G-2.2GHz where the high-frequency antenna unit operates, its maximum left-hand rotation gain is greater than 6.2dBi; within the frequency band of 1.98G-2.01GHz where the low-frequency antenna unit operates, its maximum left-hand rotation gain is greater than 5.1dBi; thus, it can be seen that this antenna has a high maximum left-hand rotation gain.

[0057] Please see Figure 13 At 1.99 GHz, the elevation angle range of the E-plane left-handed gain of the base station antenna of this application with a gain greater than 0 dBi is -55 to 57°, and the elevation angle range of the H-plane left-handed gain with a gain greater than 0 dBi is -58 to 55°.

[0058] Please see Figure 14 At 2.19 GHz, the elevation angle range of the base station antenna of this application with a left-handed gain greater than 0 dBi in the E-plane is -69 to 67°, and the elevation angle range of the left-handed gain greater than 0 dBi in the H-plane is -64 to 71°. This antenna exhibits high left-handed gain and low elevation angle gain.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of this application as described above, which are not provided in detail for the sake of brevity; although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A base station antenna, characterized in that, include: The first radiation layer, the first dielectric layer, the second radiation layer, the second dielectric layer, and the PCB motherboard are stacked sequentially from top to bottom. The first radiating layer is provided with a first feed point and a second feed point; The second radiative layer is provided with a third feed point and a fourth feed point; The first feed point, the second feed point, the third feed point, and the fourth feed point are respectively connected to the phase-shifting network on the PCB motherboard through metal pillars that penetrate the corresponding dielectric layer and metal layer.

2. The base station antenna according to claim 1, characterized in that, An annular groove is provided on the first dielectric layer and / or the second dielectric layer.

3. The base station antenna according to claim 2, characterized in that, The first dielectric layer has a first annular groove on the side facing the second radiating layer; and / or, the second dielectric layer has a second annular groove on the side facing the PCB motherboard.

4. The base station antenna according to claim 1, characterized in that, It also includes a grounding hole, which is sequentially disposed through the first radiating layer, the first dielectric layer, the second radiating layer, the second dielectric layer, and the PCB motherboard.

5. The base station antenna according to claim 1, characterized in that, The first radiating layer and the second radiating layer are metal layers; the first dielectric layer and the second dielectric layer are insulating dielectric layers; the PCB motherboard is a printed circuit board.

6. The base station antenna according to claim 1, characterized in that, The first dielectric layer has a first dielectric via, the second radiating layer has a first metal via, the second dielectric layer has a third dielectric via, and the PCB motherboard has a third metal via. It also includes a first metal pillar, the upper end of which is electrically connected to the first feed point, and the lower end of which passes through the first dielectric hole, the first metal hole, and the third dielectric hole in sequence, and is electrically connected to the phase-shifting network on the PCB motherboard through the third metal hole.

7. The base station antenna according to claim 1, characterized in that, The first dielectric layer has a second dielectric via, the second radiating layer has a second metal via, the second dielectric layer has a fourth dielectric via, and the PCB motherboard has a fourth metal via. It also includes a second metal pillar, the upper end of which is electrically connected to the second feed point, and the lower end of which passes through the second dielectric hole, the second metal hole, and the fourth dielectric hole in sequence, and is electrically connected to the phase-shifting network on the PCB motherboard through the fourth metal hole.

8. The base station antenna according to claim 1, characterized in that, The second dielectric layer has a fifth dielectric via, and the PCB motherboard has a fifth metal via; It also includes a third metal pillar, the upper end of which is electrically connected to the third feed point, and the lower end of which passes through the fifth dielectric via and is electrically connected to the phase-shifting network on the PCB motherboard through the fifth metal via.

9. The base station antenna according to claim 1, characterized in that, The second dielectric layer has a sixth dielectric via, and the PCB motherboard has a sixth metal via; It also includes a fourth metal pillar, the upper end of which is electrically connected to the fourth feed point, and the lower end of which passes through the sixth dielectric via and is electrically connected to the phase-shifting network on the PCB motherboard through the sixth metal via.

10. The base station antenna according to claim 1, characterized in that, The first radiating layer, the first dielectric layer, the second radiating layer, the second dielectric layer, and the PCB motherboard are circular plates with progressively increasing diameters.

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