Antenna structure and electronic device

Abstract

The embodiments of the present application relate to the technical field of antennas. Provided are an antenna structure and an electronic device, which are used for solving the problem of the contradiction between improvements of communication specifications and the miniaturization of electronic devices. The antenna structure provided in the embodiments of the present application comprises: a radiator assembly, a bearing board and a circuit board, wherein the radiator assembly comprises a first radiator and a second radiator, which are arranged at an interval, and a third radiator, which has a first feed terminal and a second feed terminal; the bearing board is used for bearing the first radiator and the second radiator; the circuit board is used for bearing the third radiator; the circuit board has a first electrical connection terminal and a second electrical connection terminal, the first electrical connection terminal being coupled to the first feed terminal, and the second electrical connection terminal being coupled to the second feed terminal; there is a gap between the circuit board and the bearing board; and the first radiator and the third radiator form a first capacitor at the gap position, and the second radiator and the third radiator form a second capacitor at the gap position.

Description

An antenna structure and electronic device

[0001] This application claims priority to Chinese Patent Application No. 202411640583.4, filed on November 15, 2024, entitled “An Antenna Structure and Electronic Device”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of antenna technology, and more particularly to an antenna structure and electronic device. Background Technology

[0003] With the development of communication technology and the continuous improvement of communication specifications, the number of antennas integrated into electronic devices is also increasing. In multi-antenna systems, maintaining high isolation between antennas is crucial to ensuring clear signal transmission. High isolation reduces crosstalk between antennas and improves system performance. Increasing the antenna spacing is a direct and effective way to improve antenna isolation. However, this approach conflicts with the need for improved communication specifications and miniaturization of electronic devices. If prioritizing the size of the electronic device, the distance between antennas needs to be reduced, leading to enhanced coupling effects between multiple antennas and affecting signal purity and radiation efficiency. If prioritizing communication specifications, the number of antennas needs to be increased, and the structure of the electronic device needs to be adapted to the antenna layout, thus increasing the size of the electronic device. Therefore, there is a contradiction between improving communication specifications and miniaturizing electronic devices. Summary of the Invention

[0004] This application provides an antenna structure and electronic device that addresses the miniaturization issue of electronic devices in the context of continuously improving communication specifications.

[0005] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0006] A first aspect of this application provides an antenna structure, including: a radiator assembly, a carrier plate, and a circuit board. The radiator assembly includes a first radiator and a second radiator spaced apart, and a third radiator. The third radiator has a first feed terminal and a second feed terminal. The carrier plate supports the first and second radiators. The circuit board supports the third radiator. The circuit board has a first electrical connection terminal and a second electrical connection terminal. The first electrical connection terminal is coupled to the first feed terminal, and the second electrical connection terminal is coupled to the second feed terminal. A gap exists between the circuit board and the carrier plate. A first capacitor is formed between the first and third radiators at the gap location, and a second capacitor is formed between the second and third radiators at the gap location.

[0007] As described above, the first radiator, second radiator, and third radiator, arranged at intervals, constitute the radiator assembly of this antenna structure. The first feed terminal of the third radiator is coupled to the first electrical connection terminal on the circuit board, and the second feed terminal of the third radiator is coupled to the second electrical connection terminal on the circuit board. Therefore, the circuit board can feed power to the first feed terminal and the second feed terminal through the first and second electrical connection terminals respectively, thereby achieving the purpose of feeding power from the circuit board to the radiator assembly. Furthermore, a portion of the radiator assembly, such as the first and second radiators, is disposed on the carrier plate, while another portion of the radiator assembly, such as the third radiator, is disposed on the circuit board. Therefore, it is not necessary to dispose of the entire radiator assembly on the circuit board, thereby reducing the volume of the portion of the radiator assembly on the circuit board. As the volume of the radiator assembly decreases, the clearance requirement of the radiator assembly on the circuit board also decreases. In other words, the antenna structure provided in this application embodiment has a small clearance requirement, which can solve the problem of insufficient clearance on the circuit board caused by an increase in the number of antennas, thus reducing the impact on the size of the electronic device.

[0008] Based on this, a first capacitor is formed between the first and third radiators at the gap between the circuit board and the carrier plate, allowing them to couple. Similarly, a second capacitor is formed between the second and third radiators at the same gap, enabling them to couple. This allows the capacitance values ​​of the first and second capacitors to be adjusted by changing the size of the gap, thereby expanding the bandwidth of the antenna structure. In other words, the antenna structure provided in this embodiment has broadband performance, ensuring higher communication specifications without increasing the number of antennas, thus resolving the contradiction between increasing antenna numbers and miniaturization of electronic devices in the context of continuously improving communication specifications.

[0009] In one possible implementation, the antenna structure operates in a frequency band comprising a first sub-band and a second sub-band. The first sub-band includes a first minimum value and a first maximum value, and the second sub-band includes a second minimum value and a second maximum value. The first maximum value is the same as the second minimum value. Thus, the frequency points between the minimum value of the first sub-band and the maximum value of the second sub-band form a continuous frequency band. This is one manifestation of the broadband performance of the antenna structure provided in this application within the operating frequency band, which can guarantee higher communication specifications without increasing the number of antennas.

[0010] In one possible implementation, the antenna structure operates in a frequency band comprising a first sub-band and a second sub-band. The first sub-band includes a first minimum value and a first maximum value, and the second sub-band includes a second minimum value and a second maximum value. The second minimum value is greater than the first minimum value and less than the first maximum value, while the second maximum value is greater than the first maximum value. Similarly, the frequency points between the minimum value of the first sub-band and the maximum value of the second sub-band form a continuous frequency band. This is another manifestation of the broadband performance of the antenna structure provided in this application within the operating frequency band, which can guarantee higher communication specifications without increasing the number of antennas.

[0011] In one possible implementation, the radiator assembly generates a first resonance in a first sub-band when operating in a first mode. When operating in a second mode, the radiator assembly generates a second resonance in a second sub-band. Both the first and second capacitors are located at the zero-current point of the radiator assembly when operating in the second mode. This is because the position formed by the first and second capacitors is located at the zero-current point of the radiator assembly in the second mode. Adjusting the capacitance values ​​of the first and second capacitors changes the frequency of the first resonance, while the frequency of the second resonance remains unchanged. By adjusting the size of the gap, the capacitance values ​​of the first and second capacitors can be adjusted, causing the frequency of the first resonance to move closer to the frequency of the second resonance. This is one implementation that allows the first and second sub-bands to form a continuous frequency band. After the first and second sub-bands form a continuous frequency band, the bandwidth of the antenna structure can be extended, giving the antenna structure broadband performance.

[0012] In one possible implementation, the capacitance values ​​of the first capacitor and the second capacitor are equal. This means that the first capacitor is a distributed capacitance formed by the gap between the first and third radiators, and the second capacitor is a distributed capacitance formed by the gap between the second and third radiators. The equal capacitance values ​​of the first and second capacitors imply that the gap between the first and third radiators is equal to the gap between the second and third radiators. Furthermore, since both the first and second radiators are located on the carrier plate, and the third radiator is located on the circuit board, this also means that the gap between the carrier plate and the circuit board is uniform.

[0013] In one possible implementation, the first mode is the fundamental mode of the radiator assembly, and the second mode is the cubic mode of the radiator assembly. In this case, the first and second capacitors are located at the zero-current position of the cubic mode of the radiator assembly. By adjusting the size of the gap, the capacitance values ​​of the first and second capacitors can be adjusted, causing the fundamental mode to move closer to the cubic mode. This is a possible example of a first and second mode provided in this application embodiment. By compressing the fundamental and cubic modes, the bandwidth of the antenna structure can be expanded, giving the antenna structure broadband performance.

[0014] In another possible implementation, the first mode is the secondary mode of the radiator assembly, and the second mode is the cubic mode of the radiator assembly. In this case, the first and second capacitors are located at the zero-current position of the cubic mode of the radiator assembly. By adjusting the gap size, the capacitance values ​​of the first and second capacitors can be adjusted, causing the secondary mode to move closer to the cubic mode. This is another possible example of a first and second mode provided in this application embodiment. By compressing the secondary and cubic modes, the bandwidth of the antenna structure can be expanded, giving the antenna structure broadband performance.

[0015] In one possible implementation, a first spacing D1 is provided between the first feed terminal and the second feed terminal, and the electrical length of the first spacing D1 is greater than or equal to 0.1λ and less than or equal to 0.5λ. Here, λ is the operating wavelength of the first mode. That is, the feed terminal spacing of the antenna structure provided in this application embodiment can be between 0.1λ and 0.5λ, with a minimum of 0.1λ. Since the first and second feed terminals are mounted on a circuit board, reducing the feed terminal spacing can reduce the net space occupied by the antenna structure on the circuit board, which is beneficial in the context of continuously improving communication specifications, addressing the contradiction between the increasing number of antennas and the miniaturization of electronic devices.

[0016] In one possible implementation, a first gap D1 is provided between the first feed terminal and the second feed terminal, the physical length of the first gap D1 being greater than or equal to 20 mm and less than or equal to 100 mm. This reduces the net space occupied by the antenna structure on the circuit board when the first resonant frequency is or approximately 1.5 GHz.

[0017] In one possible implementation, a second spacing D2 is provided between the first radiator and the second radiator, and the electrical length of the second spacing D2 is greater than or equal to 0.3λ, where λ is the operating wavelength of the first mode. This is because adjusting the second spacing D2 can adjust the differential-mode impedance and common-mode impedance of the antenna structure. Increasing the second spacing D2 brings the differential-mode impedance and common-mode impedance of the antenna structure closer together, thereby improving the isolation of the antenna. Since the first radiator and the second radiator are mounted on the carrier plate, increasing the electrical length of the second spacing D2 does not increase the space occupied by the antenna structure on the circuit board.

[0018] In one possible implementation, a second spacing D2 is provided between the first radiator and the second radiator, and the physical length of the second spacing D2 is greater than or equal to 60 mm. This improves the antenna isolation when the first resonant frequency is or approximately 1.5 GHz. Since the first and second radiators are mounted on a carrier plate, increasing the physical length of the second spacing D2 does not increase the space occupied by the antenna structure on the circuit board.

[0019] In one possible implementation, the first radiator includes a first branch extending along a first direction; the second radiator includes a second branch extending along the first direction; and the third radiator includes a third branch extending along a second direction. A first capacitor is formed at the gap between the first and third branches, and a second capacitor is formed at the gap between the second and third branches. The first and second directions are perpendicular. Since both the first and second branches extend along the first direction, the third branch can extend along a second direction perpendicular to the first direction in order to couple with both the first and second branches at the gap. Furthermore, any one of the first, second, and third radiators can be a single branch, resulting in a simpler structure, easier manufacturing, and lower costs.

[0020] In one possible implementation, the antenna structure also includes a ground plane; a third capacitor is formed between the ground plane and the third stub. This allows adjustment of the common-mode and differential-mode impedances of the antenna structure by adjusting the value of the third capacitor. The smaller the difference between the common-mode and differential-mode impedances, the higher the antenna isolation. Optionally, the third capacitor can be implemented by adjusting the linewidth of the third stub. In this case, the third capacitor is a distributed capacitor, which can reduce the number of lumped elements in the antenna structure and simplify the antenna design.

[0021] In one possible implementation, the third radiator further includes a fourth stub located between the first and second feed terminals. The first end of the fourth stub is electrically connected to the third stub, and a fourth capacitor is formed between the fourth stub and the ground plane. This allows adjustment of the common-mode and differential-mode impedances of the antenna structure by adjusting the capacitance of the fourth capacitor. A smaller difference between the common-mode and differential-mode impedances results in higher antenna isolation. Optionally, the fourth capacitor can be implemented by adjusting the linewidth of the fourth stub. In this case, the fourth capacitor is a distributed capacitor, which reduces the number of lumped elements in the antenna structure and simplifies the antenna design.

[0022] In one possible implementation, the first radiator includes a first stub and a fifth stub, the first stub extending along a first direction and the fifth stub extending along a second direction; one end of the fifth stub is connected to the end of the first stub facing the third stub; the second radiator includes a second stub and a sixth stub, the second stub extending along the first direction and the sixth stub extending along the second direction; one end of the sixth stub is connected to the end of the second stub facing the third stub; wherein the fifth and sixth stubs are located between the first and second stubs. This is because adding the fifth stub increases the coupling area between the first and third radiators, and adding the sixth stub increases the coupling area between the second and fourth radiators. The coupling area refers to the effective contact or proximity surface area between two conductors forming a capacitor; the larger the coupling area, the larger the capacitance formed at a given distance. For a given capacitance value and tolerance, a larger coupling area means the capacitance value is less affected by distance. Therefore, adding the fifth and sixth stubs reduces the influence of gap tolerance on the capacitance values ​​of the first and second capacitors. This reduces the impact of assembly errors of the carrier plate and circuit board on the electrical performance of the antenna structure during the manufacturing process.

[0023] In one possible implementation, the third radiator further includes a seventh stub and an eighth stub. The first end of the seventh stub is electrically connected to the third stub, and the second end of the seventh stub serves as a first feed terminal. The first end of the eighth stub is electrically connected to the third stub, and the second end of the eighth stub serves as a second feed terminal. In this way, the antenna structure can be fed through the seventh and eighth stubs.

[0024] In another possible implementation, the antenna structure further includes a first spring and a second spring. The first end of the first spring is electrically connected to the third branch, and the second end serves as the first feed terminal. The first end of the second spring is also electrically connected to the third branch, and the second end serves as the second feed terminal. This allows the antenna structure to be fed using both the first and second springs. Because the springs themselves have a certain degree of self-adjustment capability, they can accommodate slight assembly errors. Therefore, using spring-feed simplifies the antenna assembly process and reduces the need for precise alignment. Furthermore, the spring connection method typically eliminates the need for complex disassembly and assembly when replacement or maintenance is required, making it easier to operate.

[0025] In one possible implementation, the third radiator also includes a fifth capacitor and a sixth capacitor; the fifth capacitor is connected in series between the third and seventh stubs; and the sixth capacitor is connected in series between the third and eighth stubs. In this way, since the second end of the seventh stub serves as the first feed terminal and the second end of the eighth stub serves as the second feed terminal, the fifth and sixth capacitors are effectively connected in series near the feed terminals. By connecting capacitors in series near the feed terminals, the input impedance of the antenna can be changed. By adjusting the capacitance values ​​of the fifth and sixth capacitors, the input impedance can be made closer to the impedance required by the system (typically 50 ohms), thereby optimizing S11 and S22 and reducing reflections.

[0026] In one possible implementation, the carrier plate and the circuit board are arranged in an interleaved manner. This increases the adaptability of the antenna structure, allowing it to be adapted to various spatial arrangements in practical applications. For example, if the mounting space can only accommodate the circuit board in the third direction, but there is still considerable space in the fourth direction, and there is an angle between the third and fourth directions, the circuit board and the carrier plate can be arranged interleaved within the mounting space.

[0027] A second aspect of this application provides an electronic device including a first housing and any of the antenna structures provided in the first aspect of this application. At least a portion of the first housing can be reused as a carrier plate for the antenna structure. The first housing has a receiving cavity, within which the antenna structure is located. In this way, a portion of the antenna structure's traces are disposed on the first housing, and another portion is disposed on a circuit board. The traces on the first housing and the traces on the circuit board are coupled through a gap capacitor, thereby reducing the clearance requirement of the antenna structure and mitigating the conflict between increasing communication specifications and miniaturizing the electronic device.

[0028] A third aspect of this application provides an electronic device including a first housing, a second housing, and any of the antenna structures provided in the first aspect of this application. The first housing has a receiving cavity, and the second housing and the antenna structure are located within the receiving cavity. At least a portion of the second housing can be reused as a carrier plate for the antenna structure. This electronic device has the same technical effects as the antenna structure provided in the foregoing embodiments, and will not be repeated here. Attached Figure Description

[0029] Figure 1 is a schematic diagram of the working scenario of an electronic device provided in an embodiment of this application;

[0030] Figure 2 is a schematic diagram of the structure of an electronic device provided in an embodiment of this application;

[0031] Figure 3A is a schematic diagram of an antenna structure provided in an embodiment of this application, wherein the first capacitor and the second capacitor are distributed capacitors formed by a gap;

[0032] Figure 3B is a schematic diagram of another implementation of the antenna structure in Figure 3A. The antenna structure includes a first antenna element and a second antenna element.

[0033] Figure 3C is a flowchart of an antenna design method provided in an embodiment of this application;

[0034] Figure 4 shows the simulation results of the scattering parameters of the antenna structure in Figure 3A, including return loss S11 and isolation S21.

[0035] Figure 5 is a schematic diagram of another antenna structure provided in an embodiment of this application, wherein the first capacitor and the second capacitor are lumped capacitors;

[0036] Figure 6 is a schematic diagram of the current distribution of the antenna structure in Figure 5;

[0037] Figure 7 shows the simulation results of the scattering parameter S11 of the antenna structure in Figure 5, with capacitance C taken as 0Ω, 3pf, 0.3pf and 0.03pf respectively;

[0038] Figure 8 shows the simulation results of the scattering parameter S21 of the antenna structure in Figure 5, with capacitance C taken as 0Ω, 3pf, 0.3pf and 0.03pf respectively;

[0039] Figure 9 shows the simulation results of the scattering parameters of the antenna structure in Figure 5. The capacitance C is 0.03 pf, and the spacing D between the first antenna element and the second antenna element is 20 mm.

[0040] Figure 10 shows the simulation results of the Smith chart of the antenna structure in Figure 5. The capacitance C is 0.03pf and the spacing D between the first antenna element and the second antenna element is 20mm.

[0041] Figure 11 shows the simulation results of the scattering parameters S11 of the antenna structure in Figure 5. The spacing D between the first antenna element and the second antenna element is 20mm, 40mm, and 60mm, respectively.

[0042] Figure 12 shows the simulation results of the scattering parameter S21 of the antenna structure in Figure 5. The spacing D between the first antenna element and the second antenna element is 20mm, 40mm, and 60mm, respectively.

[0043] Figure 13 shows the simulation results of the Smith chart of the antenna structure in Figure 5. The spacing D between the first antenna element and the second antenna element is 20mm, 40mm, and 60mm, respectively.

[0044] Figure 14 is a schematic diagram of another antenna structure provided in the embodiment of this application. This antenna structure is based on the antenna structure in Figure 5, which increases the second spacing D2 of the antenna element by 2 / 3.

[0045] Figure 15 is a schematic diagram of the current distribution of the antenna structure in Figure 14;

[0046] Figure 16 shows the simulation results of the scattering parameters of the antenna structure in Figure 14;

[0047] Figure 17 shows the simulation results of the Smith chart of the antenna structure in Figure 14;

[0048] Figure 18 is a schematic diagram of another antenna structure provided in an embodiment of this application. This antenna structure is based on the antenna structure in Figure 14 with the addition of a horizontal stub.

[0049] Figure 19 shows the simulation results of the scattering parameters of the antenna structure in Figure 18;

[0050] Figure 20 shows the simulation results of the Smith chart of the antenna structure in Figure 18;

[0051] Figure 21 is a schematic diagram of another antenna structure provided in an embodiment of this application. This antenna structure is based on the antenna structure in Figure 18, with a capacitor connected in series on the horizontal stub.

[0052] Figure 22 shows the simulation results of the Smith chart of the antenna structure in Figure 21;

[0053] Figure 23 is a schematic diagram of another antenna structure provided in an embodiment of this application. This antenna structure is based on the antenna structure in Figure 21 with the addition of a vertical stub.

[0054] Figure 24 shows the simulation results of the Smith chart of the antenna structure in Figure 23;

[0055] Figure 25 is a schematic diagram of another antenna structure provided in the embodiment of this application. This antenna structure is based on the antenna structure in Figure 23, with a capacitor connected in series on the vertical stub.

[0056] Figure 26 shows the simulation results of the Smith chart of the antenna structure in Figure 25;

[0057] Figure 27 shows the simulation results of the scattering parameters of the antenna structure in Figure 25;

[0058] Figure 28 is a schematic diagram of another implementation of the antenna structure in Figure 3A. This antenna structure is obtained by replacing all the distributed capacitors in the antenna structure in Figure 3A with lumped capacitors, and it is also obtained by connecting a capacitor in series near the feed end based on the antenna structure in Figure 25.

[0059] Figure 29 is a schematic diagram of the current distribution of the antenna structure in Figure 3A;

[0060] Figure 30 is a schematic diagram of another implementation of the antenna structure in Figure 25, which is an implementation of the antenna structure in Figure 25 by replacing part of the capacitor with a distributed capacitor;

[0061] Figure 31 shows the simulation results of the scattering parameter S11 of the antenna structure in Figure 30, with the gap G taken as 0.5mm, 1mm and 1.5mm respectively;

[0062] Figure 32 shows the simulation results of the scattering parameter S21 of the antenna structure in Figure 30, with the gap G taken as 0.5mm, 1mm and 1.5mm respectively;

[0063] Figure 33 shows the simulation results of the Smith chart of the antenna structure in Figure 30, with the gap G taken as 0.5mm, 1mm and 1.5mm respectively;

[0064] Figure 34 is a schematic diagram of another antenna structure provided in an embodiment of this application, which adds a fifth and a sixth stub based on Figure 3A;

[0065] Figure 35 shows the simulation results of the scattering parameters of the antenna structure in Figure 34, with lengths L of 0 mm, 3 mm, 6 mm and 9 mm respectively.

[0066] Figure 36 shows the simulation results of the scattering parameters of the antenna structure in Figure 34, with a length L of 9 mm;

[0067] Figure 37 shows the simulation results of the efficiency of the antenna structure in Figure 34, with a length L of 9 mm;

[0068] Figure 38 shows the antenna radiation pattern of the antenna structure in Figure 34, with a length L of 9 mm.

[0069] Figure 39A is a schematic diagram of another implementation of the antenna structure in Figure 34, in which the carrier plate and the circuit board are arranged in a cross manner with an included angle of α;

[0070] Figure 39B is a schematic diagram of the structure in the xz plane when the included angle in Figure 39A is 90 degrees;

[0071] Figure 40 is a schematic diagram of the structure in the xy plane when the included angle in Figure 39A is 90 degrees;

[0072] Figure 41 shows the simulation results of the scattering parameters of the antenna structure in Figure 40, with the gap G being 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm and 2.8mm.

[0073] Figure 42 shows the simulation results of the efficiency of the antenna structure in Figure 40, with the gap G being 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm and 2.8mm.

[0074] Figure 43 is a schematic diagram of the structure in the xy plane when the included angle is 90 degrees in Figure 39A. The excess clearance on the circuit board in the antenna structure shown in Figure 40 is filled by grounding.

[0075] Figure 44 shows the simulation results of the scattering parameters of the antenna structure in Figure 43, with the gap G taken as 2.5 mm;

[0076] Figure 45 shows the simulation results of the efficiency of the antenna structure in Figure 43, with the gap G taken as 2.5 mm;

[0077] Figure 46 shows the simulation results of the radiation pattern of the antenna structure in Figure 43, with the gap G taken as 2.5mm;

[0078] Figure 47 shows the simulation results of the scattering parameters of the antenna structure in Figure 43, with the gap G being 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm and 2.8mm.

[0079] Figure 48 shows the simulation results of the efficiency of the antenna structure in Figure 43, where the gap G is 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm and 2.8mm;

[0080] Figure 49 is a schematic diagram of the structure of an electronic device provided in an embodiment of this application, wherein the housing of the electronic device is reused as a carrier plate for the antenna structure;

[0081] Figure 50 is a schematic diagram of another electronic device provided in an embodiment of this application. Inside the housing of the electronic device, the housing of other structures is reused as the carrier plate of the antenna structure.

[0082] Figure 51 is a schematic diagram of another electronic device provided in an embodiment of this application. The angle between the housing of other structures and the circuit board of the antenna structure is greater than 0 degrees and less than or equal to 180 degrees. Detailed Implementation

[0083] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.

[0084] In the following description, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0085] Furthermore, in this application, directional terms such as "upper" and "lower" are defined relative to the orientation of the components shown in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the orientation of the components in the accompanying drawings.

[0086] The limitations mentioned in this application, such as collinearity, symmetry (e.g., axial symmetry, or central symmetry), parallelism, perpendicularity, orthogonality, and similarity (e.g., same length, same width, etc.), are all relative to the current technological level and not absolute, strict mathematical definitions. Collinearity of three elements can be understood as the line connecting two elements, or its extension, intersecting with another element, or the closest distance to another element being approximately 2mm. In one embodiment, collinear elements may include, for example, structural components that realize a "feed terminal" or "ground terminal," such as protruding structures, springs, or tabs on the inner surface of a conductive frame. A predetermined angular deviation may exist between two mutually parallel or perpendicular components. In one embodiment, the predetermined threshold may be less than or equal to a threshold of 1mm, for example, the predetermined threshold may be 0.5mm or 0.1mm. In one embodiment, the predetermined angle may be an angle within the range of ±10°, for example, a predetermined angle deviation of ±5°.

[0087] In this application, unless otherwise expressly specified and limited, the term "connection" shall be interpreted broadly. For example, "connection" may be a fixed mechanical connection, a detachable mechanical connection, or an integral part; or, "connection" may be a direct connection or an indirect connection through an intermediate medium.

[0088] Furthermore, unless otherwise explicitly specified and limited, the term "coupling" should be interpreted broadly. For example, "coupling" can refer to a direct electrical connection, such as physical contact and electrical conduction between two components. It can also be understood as the electrical connection between different components in a circuit structure through physical lines that can transmit electrical signals, such as copper foil or wires on a printed circuit board (PCB), to transmit electrical signals. Alternatively, "coupling" can refer to an indirect electrical connection between two components through an intermediate medium. Or, "coupling" can refer to an electrical connection between two components in a non-contact manner, such as a capacitive coupling between two components to transmit electrical signals.

[0089] This application provides an electronic device. This electronic device can transmit and receive signals via an antenna. The electronic device can employ one or more of the following communication technologies: Bluetooth (BT), Global Positioning System (GPS), Wireless Fidelity (WiFi), Global System for Mobile Communications (GSM), Wideband Code Division Multiple Access (WCDMA), Long Term Evolution (LTE), 5G, and other future communication technologies.

[0090] The electronic devices in this application embodiment may include devices that directly interface with the operator's network, including but not limited to: Customer Premise Equipment (CPE), telephones, wireless routers, firewalls, computers, optical modems, and 4G-to-WiFi wireless routers. Electronic devices may also include mobile phones, tablets, laptops, smart home devices, smart bracelets, smartwatches, smart helmets, and smart glasses. Furthermore, electronic devices may include: handheld devices with wireless communication capabilities, computing devices or other processing devices connected to a wireless modem, in-vehicle devices, electronic devices in 5G networks, or electronic devices in future evolved public land mobile networks (PLMNs), etc., but this application embodiment is not limited in this regard.

[0091] For ease of explanation, the following description uses an electronic device as a CPE. A CPE is a communication device located at the end-user's premises, which can be a mobile station (MS) or a subscriber station (SS). As shown in Figure 1, the function of a CPE is signal relay. A CPE can convert cellular signals such as LTE, WCDMA, GSM, and 5G mobile networks (5G new radio, 5G NR) into Ethernet or WiFi signals common to mobile terminals such as smartphones, tablets, and laptops, and can support multiple mobile terminals accessing the internet simultaneously. For example, routers have limited range for spreading network signals; the signal is weakened when encountering obstructions such as walls. In this case, the CPE can act as a signal repeater, relaying the signal emitted by the router again, thereby expanding the signal coverage area. For example, a CPE can also relay 4G or 5G mobile network signals emitted by the operator's base station through a built-in subscriber identification module (SIM card), providing connectivity for other devices. In addition, CPE devices can typically support multiple mobile terminals to access simultaneously, making them widely applicable to homes, hospitals, factories, shopping malls, offices, and other locations. Compared to wired networks, their application scenarios are more flexible and network setup is more convenient.

[0092] As shown in Figure 2, an electronic device such as a CPE (Content Provider Equipment) includes an electronic device 01 comprising a first housing 011 and a circuit board assembly 02. The circuit board assembly 02 is located within the cavity enclosed by the housing 011. The electronic device 01 may also include an antenna structure 03 (also referred to as an "antenna"). This application embodiment does not limit the form and arrangement of the antenna structure 03 in the electronic device 01. The antenna structure 03 can be a PCB printed antenna, a bracket antenna, a wall-mounted small board antenna, etc. The following description uses a PCB printed antenna structure 03, arranged on the circuit board assembly 02, as an example. Since antenna (also called an "antenna structure") signal transmission cannot pass through conductors, in the design of the electronic device 03, an area free of other conductive materials or electromagnetic interference bodies needs to be reserved around the antenna structure 03 to keep the antenna structure 03 away from various metal components, thereby ensuring the omnidirectional communication effect of the antenna. This area is called the "clearance".

[0093] With the development of communication technology, multi-input multi-output (MIMO) technology is widely used in terminal products, leading to an increasing number of antennas in electronic devices such as CPE equipment. This increase in antenna numbers presents new challenges for electronic devices using various antenna types. For example, PCB-printed antennas face significant clearance issues, bracket antennas face increased assembly complexity due to increased materials, and wall-mounted small board antennas face complex cable management. Solving these problems requires providing more internal space for electronic devices, posing a challenge to miniaturization. Therefore, maintaining miniaturization of electronic devices while continuously improving communication standards is a key issue in electronic device antenna design.

[0094] To address the aforementioned issues, this application provides an antenna structure that can resolve the contradiction between the increasing number of antennas and the miniaturization of electronic devices in the context of continuously improving communication specifications.

[0095] In some embodiments, as shown in FIG3A, the antenna structure 03 provided in this application embodiment includes: a radiator assembly 031, a carrier plate 032, and a circuit board 033. The radiator assembly 031 includes a first radiator 0311 and a second radiator 0312 spaced apart, and a third radiator 0313. The third radiator 0313 has a first feed terminal 0341 and a second feed terminal 0342. The carrier plate 032 is used to support the first radiator 0311 and the second radiator 0312. The circuit board 033 is used to support the third radiator 0313. The circuit board 033 has a first electrical connection terminal 0331 and a second electrical connection terminal 0332. The first electrical connection terminal 0331 is coupled to the first feed terminal 0341, and the second electrical connection terminal 0332 is coupled to the second feed terminal 0342. A gap G exists between the circuit board 033 and the carrier plate 032. The first radiator 0311 and the third radiator 0313 form a first capacitor C1 at the gap G position, and the second radiator 0312 and the third radiator 0313 form a second capacitor C2 at the gap G position.

[0096] For ease of description, an xyz coordinate axis is established in Figure 3A. The xy plane is parallel to the plane containing circuit board 033, and the z direction is perpendicular to the plane containing circuit board 033. The y direction is called the first direction y, the x direction is called the second direction x, and the z direction is called the third direction z. The plane containing circuit board 033 is also the plane containing circuit board assembly 02 in Figure 2. The coordinate system definitions in subsequent figures are similar and will not be repeated.

[0097] As described above, the first radiator 0311, the second radiator 0312, and the third radiator 0313, arranged at intervals, constitute the radiator assembly 031 of the antenna structure 03. Furthermore, a portion of the radiator assembly 031, such as the first radiator 0311 and the second radiator 0312, is disposed on the support plate 032, while another portion, such as the third radiator 0313, is disposed on the circuit board 033. Therefore, it is not necessary to dispose of the entire radiator assembly 031 on the circuit board 033, thereby reducing the volume of the portion of the radiator assembly 031 on the circuit board 033. As the volume of the radiator assembly 031 decreases, the clearance requirement of the radiator assembly 031 on the circuit board 033 also decreases. In other words, the antenna structure 03 provided in this embodiment has a small clearance requirement, which can solve the problem of insufficient clearance on the circuit board 033 caused by an increase in the number of antennas, thus reducing the impact on the size of the electronic device.

[0098] In this context, clearance refers to the non-conductive space surrounding the antenna structure to ensure its effective signal reception and transmission. The size and design of the clearance directly affect the antenna's radiation efficiency, matching status, and signal quality. For example, metal shields electromagnetic waves, therefore a certain amount of space is required around the antenna structure to prevent metal coverage. For instance, for PCB-printed antennas, copper cannot be laid near the antenna structure. The area without copper is called clearance, and the area with copper is called ground.

[0099] Furthermore, the first feed terminal 0341 of the third radiator 0313 is coupled to the first electrical connection terminal 0331 on the circuit board 033, and the second feed terminal 0342 of the third radiator 0313 is coupled to the second electrical connection terminal 0332 on the circuit board 033. Therefore, the circuit board 033 can supply power to the first feed terminal 0341 and the second feed terminal 0342 through the first electrical connection terminal 0331 and the second electrical connection terminal 0332 respectively, so as to achieve the purpose of powering the radiator assembly 031.

[0100] In some embodiments, as shown in FIG3B, the antenna structure 03 includes a first antenna element 03A and a second antenna element 03B. The first antenna element 03A includes a first radiator 0311 and a first portion 0313a of a third radiator 0313. The second antenna element 03B includes a second radiator 0312 and a second portion 0313b of the third radiator 0313. The first portion 0313a includes a first feed terminal 0341, and the second portion 0313b includes a second feed terminal 0342. That is, the first antenna element 03A includes a first feed terminal 0341, and the second antenna element 03B includes a second feed terminal 0342.

[0101] Based on this, a first capacitor C1 is formed at the gap G between the first radiator 0311 and the third radiator 0313, specifically at the first portion 0313a. Therefore, the first radiator 0311 and the first portion 0313a of the third radiator 0313 can be coupled through the first capacitor C1 to form a first antenna unit 03A. A second capacitor C2 is formed at the aforementioned gap G between the second radiator 0312 and the second portion 0313b of the third radiator 0313. Therefore, the second radiator 0312 and the second portion 0313b of the third radiator 0313 can be coupled through the second capacitor C2 to form a second antenna unit 03B.

[0102] In this way, the capacitance values ​​of the first capacitor C1 and the second capacitor C2 can be adjusted by changing the size of the gap G. Adjusting the capacitance value of the first capacitor C1 can extend the bandwidth of the first antenna element 03A. Adjusting the capacitance value of the second capacitor C2 can extend the bandwidth of the second antenna element 03B. The antenna structure 03, composed of multiple antenna elements with broadband performance, also has broadband performance, which can ensure higher communication specifications without increasing the number of antennas, thereby improving the contradiction between the increasing number of antennas and the miniaturization of electronic devices in the context of continuously improving communication specifications. Here, bandwidth, also known as frequency range, refers to the range of operating frequencies of the antenna.

[0103] It should be noted that in this example, "antenna element" refers to both the first and second antenna elements. However, in other examples, antenna structure 03 may include more antenna elements. For example, antenna structure 03 may also include a third antenna element. By adjusting the size of the gap, the bandwidth of the third and fourth antenna elements can be widened using the same principle.

[0104] It is understood that in the embodiments of this application, "antenna" and "antenna structure" refer to the same concept. The use of "antenna" focuses on describing the electromagnetic performance of the antenna structure, while the use of "antenna structure" focuses on describing the mechanical performance of the antenna. The mechanical-electromagnetic coupling of the antenna determines that the electromagnetic performance of the antenna is closely related to its mechanical structure.

[0105] It is understood that the feed end (including the first feed end 0341 and the second feed end 0342) can be considered as the location where the third radiator 0313 and the circuit board 033 are electrically connected, and the electrical connection end (including the first electrical connection end 0331 and the second electrical connection end 0332) can be considered as the location where the circuit board 033 and the third radiator 0313 are electrically connected. In this embodiment, the term "end" cannot be narrowly interpreted as necessarily an endpoint or end point physically disconnected from other radiators; it can also be considered as a point or segment on a continuous radiator. In one embodiment, "end" can include a coupling region on the radiator that couples to other conductive structures. For example, the feed end can be a connection region on the radiator that is coupled to or coupled to a part of the feed circuit (e.g., a region facing a part of the feed circuit).

[0106] It should be noted that the capacitors in the embodiments of this application can be understood as lumped capacitance and / or distributed capacitance. Lumped capacitance refers to capacitive components, such as capacitor elements. Distributed capacitance (or distributed capacitance) refers to the equivalent capacitance formed by two conductive components separated by a certain gap. The capacitance formed by the gap between adjacent radiators in this example is a type of distributed capacitance. The capacitance formed between the metal traces of the antenna structure and the ground plane is also a type of distributed capacitance. The setting of distributed capacitance should be adapted to the specific structure of the antenna itself.

[0107] In all embodiments of the antenna structure 03 provided in this application, the lumped capacitor can be replaced with a distributed capacitor, and vice versa. The example uses a lumped capacitor to facilitate adjusting the capacitance value during the design phase. The example uses a distributed capacitor because the distributed capacitor is naturally formed by the antenna structure, facilitating simplification of the antenna structure during the production phase.

[0108] To verify the broadband performance of the antenna structure in Figure 3A, the scattering parameters of the antenna structure 03 shown in Figure 3A were simulated, and the simulation results are shown in Figure 4. The scattering parameters in this embodiment, also known as S-parameters, are important parameters in microwave transmission. The scattering parameters include: input return loss S11, output return loss S22, forward transmission coefficient S21, and reverse transmission coefficient S12. Sij represents the energy input from port j and measured at port i. For example, S11 is the reflection coefficient of port 1 when port 2 is matched, S22 is the reflection coefficient of port 2 when port 1 is matched, S21 is the transmission coefficient from port 1 to port 2 when two ports are matched, and S12 is the transmission coefficient from port 2 to port 1 when one port is matched. The values ​​of the S-parameters are generally expressed in decibels, ranging from 0 dB to negative infinity.

[0109] Curve ① in Figure 4 is the S11 curve (the return loss curve of antenna structure 03 in Figure 3A). Return loss is a parameter that measures the degree of reflection in a signal transmission system, defined as the ratio of incident power to reflected power, and is generally expressed in decibels. Return loss can be calculated using S11. When S11 = 0 dB, it means that the energy is completely reflected, and the return loss is at its maximum. When S11 = -∞ dB, it means that the energy is not reflected, and the return loss is at its minimum. In engineering, it is desirable for the S11 value to be as small as possible. In this embodiment, S11 is less than -6 dB as an example. The bandwidth where S11 is less than -6 dB can be considered as the operating frequency band of the antenna.

[0110] Curve ② in Figure 4 is the S21 curve (the isolation curve of antenna structure 03 in Figure 3A). Isolation refers to the ratio of the signal received by one antenna through another to the signal received by the transmitting antenna. Isolation is a physical quantity used to measure the degree of mutual coupling between antennas. Assuming that two antennas form a two-port network, the isolation between the two antennas can be represented by the parameters S21 and S12. In this case, S21 and S12 are usually negative, and the smaller the parameters S21 and S12, the greater the isolation between the antennas and the smaller the mutual coupling between them.

[0111] Based on this, curve ① in Figure 4 shows that the operating frequency band of antenna structure 03 is between 1.427GHz and 2.69GHz. Curve ② shows that within the operating frequency band, the isolation of antenna structure 03 is less than -15dB, indicating good performance. In other words, antenna structure 03 is a broadband antenna covering the entire LTE mid-to-high frequency band (1.427GHz to 2.69GHz).

[0112] Broadband refers to the frequency range of an antenna being able to cover a relatively wide bandwidth.

[0113] Continuing with Figure 4, curve ① shows that antenna structure 03 has two return loss dips near 1.5GHz and 2.3GHz. These are the two resonant points of antenna structure 03. These two resonant points are located in two sub-bands, for example, the first resonant point (e.g., 1.5GHz) is located in the first sub-band, and the second resonant point (e.g., 2.3GHz) is located in the second sub-band. The first sub-band includes a first minimum value fmin1 and a first maximum value fmax1, which together constitute the range of the first sub-band (fmin1~fmax1). The second sub-band includes a second minimum value fmin2 and a second maximum value fmax2. These two values ​​together constitute the range of the second sub-band (fmin2~fmax2).

[0114] Resonance refers to an antenna structure reaching an optimized electromagnetic energy conversion state at a specific frequency, at which point the antenna can transmit or receive electromagnetic waves with maximum efficiency. The resonant frequency is also called the resonance frequency. The resonant frequency can have a frequency range, called the antenna's bandwidth (or "operating frequency"). The point of strongest resonance is called the resonant point, and the frequency corresponding to the resonant point is called the center frequency. In this embodiment, the resonant frequency range is defined as the frequency range with a return loss of less than -6dB.

[0115] In one possible implementation, the operating frequency band of antenna structure 03 consists of a first sub-band and a second sub-band. In this case, within the operating frequency band shown by curve ① in Figure 4, the first minimum value fmin1 = 1.427 GHz, and the second maximum value fmax2 = 2.69 GHz. The first maximum value fmax1 and the second minimum value fmin2 can be the same. Alternatively,

[0116] For example, the first maximum value fmax1 is the same as the second minimum value fmin2. In this case, the overlap between the first and second sub-bands is limited to the frequency point where the first maximum value fmax1 (or the second minimum value fmin2) is located. Thus, the frequency points between the minimum and maximum values ​​of the first and second sub-bands form a continuous frequency band. In other words, the broadband performance of antenna structure 03 can be directly observed from the scattering parameter curve. Applying the broadband antenna structure 03 allows electronic devices to maintain higher communication specifications without increasing the number of antennas.

[0117] For example, the second minimum value fmin2 is greater than the first minimum value fmin1 and less than the first maximum value fmax1, while the second maximum value fmax2 is greater than the first maximum value fmax1. In this case, the frequency points between the second minimum value fmin2 and the first maximum value fmax1 can be assigned to either the first sub-band or the second sub-band. Similarly, the frequency points between the minimum value of the first sub-band and the maximum value of the second sub-band can also form a continuous frequency band.

[0118] Understandably, sub-bands are often used to distinguish different resonant modes. Continuing with curve ① in Figure 4 as an example, in practice, the first resonant frequency of 1.5 GHz is often assigned to the first sub-band, and the second resonant frequency of 2.3 GHz to the second sub-band. In this case, when the antenna operates in the first sub-band, it can be said that the antenna is operating in the first mode. When the antenna operates in the second sub-band, it can be said that the antenna is operating in the second mode. The term "mode" here is defined and numbered according to specific needs.

[0119] In some embodiments, the radiator assembly 031 generates a first resonance in a first sub-band when operating in a first mode. When operating in a second mode, the radiator assembly 031 generates a second resonance in a second sub-band. Both the first capacitor C1 and the second capacitor C2 are located at the zero-current position when the radiator assembly 031 operates in the second mode. This is because, when the positions of the first capacitor C1 and the second capacitor C2 are at the zero-current position of the radiator assembly 031 in the second mode, adjusting the capacitance values ​​of the first capacitor C1 and the second capacitor C2 will change the frequency of the first resonance, while the frequency of the second resonance remains unchanged. Utilizing this characteristic, adjusting the capacitance values ​​of the first capacitor C1 and the second capacitor C2 can bring the frequency of the first resonance closer to the frequency of the second resonance. This makes it easier to reduce the return loss between the first and second resonance frequencies to below -6dB, facilitating the expansion of the bandwidth of the antenna structure 03 and giving the antenna structure 03 broadband performance.

[0120] It is understood that both the first capacitor C1 and the second capacitor C2 are located at the zero-current point when the radiator assembly 031 operates in the second mode. This is equivalent to the first capacitor C1 being located at the zero-current point when the first antenna unit 03A operates in the second mode, and the second capacitor C2 being located at the zero-current point when the second antenna unit 03B operates in the second mode.

[0121] This application does not limit the feature modes corresponding to the first mode and the second mode in its embodiments. In one possible implementation, the second mode is a higher-order mode relative to the first mode. For example, the first mode is a fundamental mode, and the second mode is a third harmonic mode. For example, the first mode is a second harmonic mode, and the second mode is a third harmonic mode.

[0122] For ease of explanation, the antenna element used in the embodiments of this application is a monopole antenna. The first mode is used as the fundamental mode, and the second mode is used as the cubic mode for explanation.

[0123] In this context, the primary and tertiary modes are characteristic modes of the antenna. Characteristic modes are used to identify all the fundamental electromagnetic modes of an antenna structure, describing the distribution of the electromagnetic field within the antenna structure and how the antenna responds to a specific frequency. For example, the primary mode, also known as the fundamental mode, refers to the antenna's most basic resonant mode. The primary mode corresponds to the lowest frequency at which the antenna can effectively radiate or receive signals, also called the fundamental frequency. The primary mode typically corresponds to the antenna's natural radiation mode. For example, the secondary mode refers to an antenna whose resonant frequency is twice the fundamental frequency. For example, the tertiary mode refers to an antenna whose resonant frequency is three times the fundamental frequency.

[0124] It is understandable that the second-order mode is a higher-order mode than the first-order mode. The third-order mode is a higher-order mode than the first-order mode, and also a higher-order mode than the second-order mode. It is also understandable that the concept of "first-order mode" differs from the aforementioned "first mode," that is, the concept of "characteristic mode" differs from the aforementioned "mode." A characteristic mode is an inherent electromagnetic mode of the antenna structure. A mode is a defined frequency artificially assigned to describe the operating frequency of an antenna structure. An antenna can resonate in more than one frequency range, and each frequency range is called a "mode." Each mode has a corresponding center frequency. If the frequency range of all modes can cover a continuous wide frequency range, the antenna is a broadband antenna. If the frequency range of all modes cannot cover a continuous wide frequency range, the antenna is a multi-band antenna. In the example of this application embodiment, the first mode is precisely the first-order mode (fundamental mode) of the antenna.

[0125] It is understood that in some embodiments, as shown in FIG3A, the capacitance value of the first capacitor C1 and the capacitance value of the second capacitor C2 can be adjusted by adjusting the size of the gap G. It is also understood that the embodiments of this application do not limit the relationship between the capacitance values ​​of the first capacitor C1 and the second capacitor C2; the capacitance values ​​of the first capacitor C1 and the second capacitor C2 can be equal or different.

[0126] For example, the capacitance values ​​of the first capacitor C1 and the second capacitor C2 are not equal. The gap between the first radiator 0311 and the third radiator 0313 is not equal to the gap between the second radiator 0312 and the third radiator 0313. Therefore, the first antenna element 03A and the second antenna element 03B operate in different frequency bands, allowing antenna structure 03 to cover a wider frequency range.

[0127] For example, the capacitance of the first capacitor C1 is equal to the capacitance of the second capacitor C2. The gap between the first radiator 0311 and the third radiator 0313 is equal to the gap between the second radiator 0312 and the third radiator 0313. Since the first radiator 0311 and the second radiator 0312 are both located on the carrier plate 032, and the third radiator 0313 is located on the circuit board 033, this also means that the gap G between the carrier plate 032 and the circuit board 033 is uniform.

[0128] As described above, the antenna structure 03 shown in Figure 3A has broadband performance, and furthermore, it can also have high isolation. To obtain the structure shown in Figure 3A, this application provides an antenna design method. As shown in Figure 3C, this method may include steps S101 to S106.

[0129] S101, a capacitor is connected in series at the current zero point of the antenna element in the second mode. This expands the bandwidth of the antenna element, giving it broadband performance. For example, as shown in Figure 3A, the first capacitor C1 is located at the current zero point when the first antenna element operates in the second mode, and the second capacitor C2 is located at the current zero point when the second antenna element operates in the second mode.

[0130] To verify the effect of S101 in expanding the bandwidth of the antenna element, as shown in FIG5, this application embodiment provides an antenna structure 03, including the aforementioned first antenna element 03A and second antenna element 03B. The first capacitor C1 and the second capacitor C2 are both lumped capacitors. The capacitance values ​​of the first capacitor C1 and the second capacitor C2 are equal, and both have a value of C. In some embodiments, the first capacitor C1 is positioned at the null position of the second mode (cubic mode) of the first antenna element 03A (e.g., at A1 in FIG6). The second capacitor C2 is positioned at the null position of the second mode (cubic mode) of the second antenna element 03B (e.g., at A2 in FIG6).

[0131] The embodiments of this application do not limit the length of the antenna elements; the length of the antenna elements is related to their operating frequency. The lengths of the first antenna element 03A and the second antenna element 03B can be equal or unequal. For example, the lengths of the first antenna element 03A and the second antenna element 03B are equal. For example, the lengths of the first antenna element 03A and the second antenna element 03B are unequal. In this way, the antenna structure 03 can cover a wider bandwidth.

[0132] For ease of explanation, the following description uses monopole antennas of the same length as the first antenna element 03A and the second antenna element 03B. In this case, the return loss curve, isolation curve, and efficiency curve of the first antenna element 03A and the second antenna element 03B all overlap. It should be understood that the return loss curve, isolation curve, and efficiency curve shown in the embodiments of this application are both the rated electrical performance curves of the first antenna element 03A and the electrical performance curves of the second antenna element 03B.

[0133] For example, when C = 0Ω, the fundamental mode corresponds to the frequency f and the corresponding wavelength λ. The electrical lengths of the first and second antenna elements are both L, where L = 1 / 4λ. For example, f = 0.77 GHz, λ = 390 mm, and L = 97.5 mm.

[0134] The wavelength, also known as the operating wavelength, can be the wavelength corresponding to the center frequency of the resonant frequency or the wavelength corresponding to the center frequency of the operating frequency band supported by the antenna. For example, assuming the center frequency of the uplink band (operating frequency band of 1GHz to 2GHz) is 1.5GHz, the operating wavelength can be the wavelength corresponding to the center frequency of 1.5GHz, or it can be the wavelength corresponding to other non-center frequencies within 1GHz to 2GHz. Electrical length refers to the ratio of the mechanical length (also known as physical length or geometric length) of the propagation medium and structure to the wavelength of the electromagnetic wave propagating on that medium and structure.

[0135] As shown in Figure 6 (current distribution diagram of antenna structure 03 in Figure 5), it can be seen that the current zero point of the fundamental mode is at the tail of the antenna element, and the current zero point of the third mode is at a position on the antenna element 1 / 3L away from the feed terminal. Therefore, the first mode can be the fundamental mode of antenna structure 03, and the second mode can be the third mode of antenna structure 03. The first capacitor C1 is connected in series at the position of the current zero point of the third mode of the first antenna element 03A, for example, at a position on the first antenna element 03A 1 / 3L away from the first feed terminal 0341. The second capacitor C2 is connected in series at the position of the current zero point of the third mode of the second antenna element 03B, for example, at a position on the second antenna element 03B 1 / 3L away from the second feed terminal 0342.

[0136] Based on this, the capacitance values ​​C of the first capacitor C1 and the second capacitor C2 were changed sequentially to C = 0Ω, C = 3pf, C = 0.3pf, and C = 0.03pf, and the scattering parameters of the antenna structure 03 were simulated. The simulation results of the return loss S11 are shown in Figure 7, and the simulation results of the isolation S21 are shown in Figure 8. Where C = 0Ω, the capacitance C is infinite, and the antenna element is in a short-circuit state at the location of capacitor C.

[0137] Points ①, ②, ③, and ④ in Figures 7 and 8 correspond to the positions of the first resonant point (the resonant point of the first mode) when C = 0Ω, C = 3pf, C = 0.3pf, and C = 0.03pf, respectively. Points ⑤, ⑥, ⑦, and ⑧ in Figures 7 and 8 correspond to the positions of the second resonant point (the resonant point of the second mode) when C = 0Ω, C = 3pf, C = 0.3pf, and C = 0.03pf, respectively. It can be seen from Figures 7 and 8 that, with the zero-current series capacitor in the second mode, as the capacitance C decreases, the frequency corresponding to the resonant point of the second mode remains essentially unchanged, while the frequency corresponding to the resonant point of the first mode increases and approaches the frequency corresponding to the resonant point of the second mode.

[0138] Therefore, by adjusting the capacitance values ​​of the first capacitor C1 and the second capacitor C2 in Figure 5, the resonant point of the first mode (fundamental mode) can be made closer to the resonant point of the second mode (tertiary mode). Based on this, it can be seen from the above that in the antenna structure 03 shown in Figure 3A, the coupling of the first radiator 0311 and the first part 0313a can form the aforementioned first capacitor C1, and the coupling of the second radiator 0312 and the second part 0313b can form the aforementioned second capacitor C2. Similarly, it can be seen that by adjusting the capacitance values ​​(i.e., the size of the gap G) of the first capacitor C1 and the second capacitor C2 in Figure 3A, the resonant point of the first mode (fundamental mode) can also be made closer to the resonant point of the second mode (tertiary mode), thereby achieving the aforementioned broadband performance of the antenna structure 03.

[0139] As shown in Figure 9 (which is the simulation result of scattering parameters when antenna structure 03 in Figure 5 has C = 0.03pf and D = 20mm), the resonant point of the first mode is or approximately 1.5GHz, and the resonant point of the second mode is or approximately 2.3GHz. The difficulty of adjusting S11 and S21 in the range of 1.5GHz-2.3GHz is much lower than the difficulty of adjusting S11 and S21 in the range of 0.77GHz-2.3GHz when C = 0.

[0140] Continuing with Figure 9, curve ① represents the return loss S11, and curve ② represents the isolation S21. When antenna structure 03 is in the first mode (fundamental mode), the electrical length of the spacing D is 0.1λ; when antenna structure 03 is in the second mode (tertiary mode), the electrical length of the spacing D is 0.15λ. The physical length of the spacing D is 20 mm. The isolation of antenna structure 03 in the first mode (fundamental mode) is -4 dB, and the isolation in the second mode (tertiary mode) is -5 dB, which is very poor.

[0141] For two or more antenna elements that are close together, they can be formed into an antenna pair. Then, common-mode (CM) and differential-mode (DM) signals can be used simultaneously for excitation to adjust the mutual coupling effect. If the CM and DM impedances of the antenna pair are the same, the coupling effect between all antenna elements in the pair can be eliminated, thereby improving the isolation between antennas. The CM and DM impedances can be observed using the Smith chart of the antenna elements.

[0142] Figure 10 (Smith chart simulation results for antenna structure 03 in Figure 5 with C = 0.03 pf and D = 20 mm) shows that at 1.5 GHz, the CM impedance Z1 in polar coordinates is Z1 = 0.6418 + j332, and the DM impedance Z3 in polar coordinates is Z3 = 0.6184 + j152.2. At 2.3 GHz, the CM impedance Z2 in polar coordinates is Z2 = 0.5349 + j330.7, and the DM impedance Z4 in polar coordinates is Z4 = 0.5746 + j120.9. The CM and DM impedances of the two modes of antenna structure 03 differ significantly, as shown in Figure 10, that is, the distance between Z1 and Z3 on the Smith chart is large, and the distance between Z2 and Z4 on the Smith chart is also large.

[0143] Taking Figure 10 as an example, in all the Smith charts in the embodiments of this application, the solid lines represent the CM impedance loop and the dashed lines represent the DM impedance loop, which will not be repeated below. Since it is difficult to directly compare the impedance values ​​in the polar coordinate system, for ease of explanation, in the following examples, only the corresponding impedance values ​​are marked in the attached figures. The specification only observes the distance between the CM impedance and the DM impedance, and does not list the specific impedance values. For example, point 1 is the position of Z1 on the Smith chart, and the impedance value of Z1 is 0.6418+j332, which is represented as "1:Z1(0.6418,332)".

[0144] Understandably, according to the above theory, the first and second antenna elements can form an antenna pair. When the CM impedance and DM impedance of the antenna pair are the same, the mutual coupling effect between the first and second antenna elements can be eliminated, thereby improving the antenna isolation. Similarly, when the CM impedance and DM impedance of the antenna pair are similar, the mutual coupling effect between the first and second antenna elements can be weakened, thus improving the antenna isolation. The similarity between the CM impedance and DM impedance at the resonant point of the antenna pair is reflected in the Smith chart as follows: the frequency corresponding to the resonant point of the antenna pair is approximately equidistant from the positions on the CM impedance circle and the DM impedance circle.

[0145] Based on this, embodiments of this application provide an antenna design method, which may further include a step of improving the isolation of the antenna structure 03. This step of improving the isolation of the antenna structure 03 may include S102 to S105 as shown in FIG3C. Specifically, S102 involves increasing the spacing between antenna elements.

[0146] To verify the effect of increasing the spacing between antenna elements in S102 on improving isolation, this application embodiment provides an antenna structure, as shown in Figure 5, where the first antenna element 03A and the second antenna element 03B have a spacing D. Taking C = 0.03 pf, and successively taking D = 20 mm, D = 40 mm, and D = 60 mm, the electrical performance of the antenna structure 03 is simulated. The simulation results of return loss S11 are shown in Figure 11, the simulation results of isolation S21 are shown in Figure 12, and the simulation results of the Smith chart are shown in Figure 13.

[0147] Curves ①, ②, and ③ in Figure 11 correspond to the return loss of the antenna structure when D = 20 mm, D = 40 mm, and D = 60 mm, respectively. It can be seen that increasing the spacing D of the antenna elements reduces the return loss in the 1.5 GHz to 2.3 GHz range. Curves ①, ②, and ③ in Figure 12 correspond to the isolation of the antenna structure when D = 20 mm, D = 40 mm, and D = 60 mm, respectively. It can be seen that increasing the spacing D of the antenna elements also reduces the antenna isolation near 1.5 GHz and 2.3 GHz. The three Smith charts in Figure 13, from left to right, correspond to the impedance of the antenna structure when D = 20 mm, D = 40 mm, and D = 60 mm, respectively. The solid coil represents the CM impedance coil, and the dashed coil represents the DM impedance coil. Comparing the three Smith charts in Figure 13, it can be seen that increasing the spacing D of the antenna elements causes the DM impedance coil to shrink, and the distance between the CM and DM impedance coils to decrease.

[0148] While directly increasing the spacing D between antenna elements can improve isolation, it also increases the net space occupied by the antenna structure on the circuit board. Therefore, in order to improve isolation while saving net space occupied by antenna elements on the circuit board, the branches in the first antenna element 03A and the second antenna element 03B in Figure 5 can be configured as shown in Figure 14. As shown in Figure 14, the first part 0313a of the third radiator 0313 (that is, the first 1 / 3 part of the first antenna element 03A in Figure 5) and the second part 0313b of the third radiator 0313 (that is, the first 1 / 3 part of the second antenna element 03B in Figure 5) are L-shaped.

[0149] As shown in Figure 14, there is a first gap D1 between the first feed terminal 0341 and the second feed terminal 0342, and a second gap D2 between the first radiator 0311 and the second radiator 0312, where D2 > D1.

[0150] For example, D1 = 20 mm and D2 = 60 mm. In this case, a simulation of the current distribution of the antenna structure in Figure 14 is performed, as shown in Figure 15. It can be observed that the change in the antenna element shape does not alter the current distribution on the antenna element. The positions of the first capacitor C1 and the second capacitor C2 remain at the zero point of the third-mode current of the antenna element. The electrical performance of antenna structure 03 in Figure 14 is then simulated.

[0151] As shown in Figure 16 (simulation results of scattering parameters for antenna structure 03 in Figure 14), curves ① and ② correspond to the return loss curve S11 and the isolation curve S21 of the antenna structure in Figure 14, respectively. The isolation of antenna structure 03 is -8dB in the first mode (fundamental mode) and -12dB in the second mode (third mode), which is an improvement over the isolation shown in Figure 9. Therefore, increasing the spacing of the last two-thirds of the antenna elements, making D2 > D1, can significantly improve the isolation of antenna structure 03.

[0152] As shown in Figure 17 (the Smith chart simulation result of antenna structure 03 in Figure 14), the solid line corresponds to the CM impedance loop of antenna structure 03 in Figure 14, and the dashed line corresponds to the DM impedance loop of antenna structure 03 in Figure 14. Point 1 is the CM impedance at 1.5 GHz, point 2 is the CM impedance at 2.3 GHz, point 3 is the DM impedance at 1.5 GHz, and point 4 is the DM impedance at 2.3 GHz. Comparing Figures 10 and 17, it can be found that the DM impedance loop shrinks, and the CM impedance loop expands. The CM impedance and DM impedance in Figure 17 are closer to those in Figure 10.

[0153] It is understood that, continuing as shown in Figure 14, the length of the first spacing D1 is not limited to 20 mm. In the antenna structure 03 provided in this application embodiment, the electrical length of the first spacing D1 is greater than or equal to 0.1λ and less than or equal to 0.5λ. Wherein, λ is the operating wavelength of the first mode. For example, the electrical length of the first spacing D1 is greater than or equal to 0.1λ and less than or equal to 0.15λ. For example, the electrical length of D1 can be 0.1λ, 0.11λ, 0.12λ, 0.13λ, 0.14λ, 0.15λ, 0.16λ, 0.2λ, 0.3λ, 0.4λ, or 0.5λ.

[0154] When the resonant point of the first mode is 1.5 GHz or approximately, the physical length of the first pitch D1 is greater than or equal to 20 mm and less than or equal to 100 mm. For example, the physical length of the first pitch D1 can be from 20 mm to 30 mm. For example, the physical length of the first pitch D1 can be 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, 32 mm, 40 mm, 60 mm, 80 mm, or 100 mm.

[0155] In other words, the minimum spacing between the feed ends of the antenna structure 03 provided in this application embodiment can be 0.1λ. Since the first feed end and the second feed end are set on the circuit board 033, reducing the spacing between the feed ends can reduce the net space occupied by the antenna structure 03 on the circuit board 033, which is beneficial to the contradiction between the increasing number of antennas and the miniaturization of electronic devices in the context of continuously improving communication specifications.

[0156] It is understood that the length of the second spacing D2 is not limited to 60 mm. In the antenna structure 03 provided in this application embodiment, the electrical length of the second spacing D2 is greater than or equal to 0.3λ, where λ is the operating wavelength of the first mode. When the resonant point of the first mode is or approximately 1.5 GHz, the physical length of the second spacing D2 is greater than or equal to 60 mm. In this way, adjusting the second spacing D2 can adjust the differential-mode impedance and common-mode impedance of the antenna structure 03. Increasing the second spacing D2 can bring the differential-mode impedance and common-mode impedance of the antenna structure 03 closer together, thereby improving the isolation of the antenna. Since the first radiator 0311 and the second radiator 0312 are disposed on the carrier plate 032, increasing the electrical length of the second spacing D2 will not increase the space occupied by the antenna structure 03 on the circuit board 033.

[0157] As can be seen from the above, when the second spacing D2 between the first radiator 0311 and the second radiator 0312 in Figure 14 is greater than the first spacing D1 between the first feed terminal 0341 and the second feed terminal 0342, the isolation of the antenna structure can be improved. Similarly, in Figure 3A, when the second spacing D2 between the first radiator 0311 in the first antenna element 03A and the second radiator 0312 in the second antenna element 03B is greater than the first spacing D1 between the first feed terminal 0341 and the second feed terminal 0342, the isolation of the antenna structure 03 can be improved.

[0158] Based on this, in order to further improve the isolation of the antenna structure, the antenna design method shown in Figure 3C may also include: S103, adding transverse stubs between antenna elements.

[0159] To verify the effect of adding a horizontal stub between antenna elements in S103 on improving isolation, this application embodiment provides an antenna structure, as shown in Figure 18. The antenna structure 03 further includes a horizontal stub 035, which connects the first antenna element 03A and the second antenna element 03B. The electrical performance of the antenna structure 03 is simulated.

[0160] As shown in Figure 19 (which is the simulation result of the scattering parameters of antenna structure 03 in Figure 18), curve ① represents the return loss S11, and curve ② represents the isolation S21. Comparing Figure 19 and Figure 16, it can be seen that the isolation at 1.5 GHz is -24 dB, and the isolation at 2.3 GHz is -30 dB. Both modes show isolation dips, indicating a significant improvement in isolation.

[0161] As shown in Figure 20 (the Smith chart simulation results of antenna structure 03 in Figure 18), point 1 represents the CM impedance at 1.5 GHz, point 2 represents the CM impedance at 2.3 GHz, point 3 represents the DM impedance at 1.5 GHz, and point 4 represents the DM impedance at 2.3 GHz. Comparing Figure 20 and Figure 17, it can be seen that the DM impedance loop converges significantly, and the low-frequency impedance changes faster than the high-frequency impedance on the DM impedance loop. In the first mode, CM impedance points 1 and DM impedance points 3 are significantly close, and in the second mode, CM impedance points 2 and DM impedance points 4 are significantly close.

[0162] As can be seen from the above, in Figure 18, the antenna structure isolation can be improved by adding horizontal stubs between antenna elements. Similarly, the part of the third radiator 0313 in Figure 3A located between the first feed terminal 0341 and the second feed terminal 0342, that is, the horizontal stub connecting the first antenna element and the second antenna element, can also achieve the effect of improving isolation.

[0163] Based on this, in order to further improve the isolation of the antenna structure, the antenna design method shown in Figure 3C may also include S104, connecting a capacitor in series on the horizontal stub, and adding a vertical stub between the middle position of the horizontal stub and the ground.

[0164] To verify the effect of the series capacitor on the horizontal stub in S104 on improving isolation, this application embodiment provides an antenna structure, as shown in Figure 21. Antenna structure 03 also includes a third capacitor C3, which is connected in series on the horizontal stub. To facilitate the subsequent addition of a vertical stub between the middle position of the horizontal stub and the ground plane, the third capacitor C3 can be equivalent to capacitors C31 and C32, which are connected in series on the horizontal stub 035. This application embodiment does not limit the capacitance value of the third capacitor C3; the specific capacitance value is determined by the structure of the antenna element. For example, the third capacitor C3 is 2pF, which is equivalent to capacitors C31 and C32 both having a capacitance value of 4pF. Based on this, the electrical performance of antenna structure 03 in Figure 21 is simulated.

[0165] As shown in Figure 22 (the simulation results of the Smith chart of antenna structure 03 in Figure 21), point 1 represents the CM impedance at 1.5 GHz, point 2 represents the CM impedance at 2.3 GHz, point 3 represents the DM impedance at 1.5 GHz, and point 4 represents the DM impedance at 2.3 GHz. Comparing Figures 20 and 22, the CM impedance points 1 and DM impedance points 3 in the first mode are actually further apart, while the CM impedance points 2 and DM impedance points 4 in the second mode show no significant change. Despite this, the introduction of the third capacitor C3 facilitates further adjustment of the antenna's electrical performance.

[0166] To verify the effect of the series capacitor on the horizontal stub in S104 and the addition of a vertical stub between the middle position of the horizontal stub and the ground plane on improving isolation, this application embodiment provides an antenna structure, as shown in Figure 23. The antenna structure 03 further includes a vertical stub 036. The vertical stub 036 connects the center of the horizontal stub 035 to the ground plane (i.e., the copper-clad area on the circuit board 033). The electrical performance of the antenna structure 03 is simulated.

[0167] As shown in Figure 24 (the simulation result of the Smith chart of antenna structure 03 in Figure 23), point 1 is the CM impedance at 1.5 GHz, point 2 is the CM impedance at 2.3 GHz, point 3 is the DM impedance at 1.5 GHz, and point 4 is the DM impedance at 2.3 GHz. Comparing Figures 20, 22, and 24, in Figure 24, the CM impedance points 1 and DM impedance points 3 in the first mode are significantly closer, while the CM impedance points 2 and DM impedance points 4 in the second mode remain essentially unchanged.

[0168] As can be seen from the above, in Figure 23, by connecting a capacitor in series on the horizontal stub and adding a vertical stub between the middle position of the horizontal stub and the ground, the isolation of the antenna structure can be improved. Similarly, the width of the horizontal stub (the stub along the second direction x) in the third radiator 0313 in Figure 3A can be equivalent to the third capacitor C3. The part of the third radiator 0313 connected to the ground point, that is, the vertical stub connected between the middle position of the horizontal stub and the ground, can also achieve the effect of improving isolation.

[0169] Based on this, in order to further improve the isolation of the antenna structure, the antenna design method shown in Figure 3C may also include S105, which involves connecting a capacitor in series on the vertical stub.

[0170] To verify the effect of connecting the capacitor in series on the vertical stub in S105 on improving isolation, this application embodiment provides an antenna structure, as shown in Figure 25. The antenna structure 03 further includes a fourth capacitor C4, which is connected in series between the vertical stub 036 and the ground plane. This application embodiment does not limit the capacitance value of the fourth capacitor C4; the specific capacitance value is determined by the structure of the antenna element. For example, the capacitance value of the fourth capacitor C4 is 7 pF, and the electrical performance of the antenna structure 03 is simulated based on this.

[0171] As shown in Figure 26 (the simulation result of the Smith chart of antenna structure 03 in Figure 25), point 1 is the CM impedance at 1.5 GHz, point 2 is the CM impedance at 2.3 GHz, point 3 is the DM impedance at 1.5 GHz, and point 4 is the DM impedance at 2.3 GHz. Comparing with Figure 24, the CM and DM impedances at other frequency points within the 1.5 GHz to 2.3 GHz band in Figure 26 are also relatively close.

[0172] As shown in Figure 27 (which is the simulation result of the scattering parameters of antenna structure 03 in Figure 25), curve ① represents the return loss S11, and curve ② represents the isolation S21. It can be seen from the S21 curve in Figure 27 that the antenna isolation is significantly improved in the frequency band from 1.5 GHz to 2.3 GHz, all below -15 dB.

[0173] As can be seen from the above, in Figure 25, by connecting a capacitor in series on the vertical stub, the isolation of the antenna structure can be improved. Similarly, the part in the middle of the third radiator 0313 in Figure 3A that connects to the ground point, that is, the width of the vertical stub connecting the middle position of the horizontal stub and the ground, can also be equivalent to the fourth capacitor C4, which can improve the isolation.

[0174] Based on this, in order to adjust the return loss of the antenna, the antenna design method shown in Figure 3C may also include S106, which involves connecting a capacitor in series near the feed end.

[0175] To verify the effect of the series capacitor near the feed terminal in S106 on adjusting the antenna return loss, this application embodiment provides an antenna structure, as shown in FIG28, in which a fifth capacitor C5 is added near the first feed terminal and a sixth capacitor C6 is added near the second feed terminal.

[0176] In the antenna structure 03 shown in Figure 28, the first capacitor C1 and the second capacitor C2 are replaced with distributed capacitors formed by gaps; the third capacitor C3 is replaced with a distributed capacitor formed by the width of the transverse stub extending along the second direction x and the ground plane; and the fourth capacitor C4 is replaced with a distributed capacitor formed by the width of the vertical stub and the ground plane. The transverse stub extending along the second direction x includes the portion of the first antenna element extending along the x direction, the transverse stub, and the portion of the second antenna element extending along the x direction. This yields the antenna structure 03 shown in Figure 3A. In other words, the antenna structure in Figure 28 and the antenna structure in Figure 3A are equivalent and have the same electrical performance. A simulation of the current distribution of the antenna structure 03 in Figure 3A is shown in Figure 29. It can be seen that the location of the gap is exactly where the zero point of the third-mode current of the antenna element is located.

[0177] As shown in Figure 4 (simulation results of scattering parameters for antenna structure 03 in Figures 28 and 3A), within the frequency band from 1.5 GHz to 2.3 GHz, S11 is less than -6 dB and S21 is less than -15 dB at all frequency points, and the bandwidth and isolation meet the application requirements. Comparing Figure 4 and Figure 27, the return loss within the operating frequency band is significantly reduced. This means that connecting a capacitor in series near the feed end can effectively adjust the antenna return loss.

[0178] It is understandable that all steps of the antenna design method shown in Figure 3C can be used separately. Using only one or a few steps can still achieve the desired beneficial effect. It is also understandable that the method shown in Figure 3C can still be used when the number of antenna elements in the antenna structure is greater than two.

[0179] Compared to antenna structure 03 in Figure 28, antenna structure 03 in Figure 3A has fewer lumped components, making it easier to implement different configurations of the circuit board and carrier board. However, since there is no explicit formula for the correspondence between distributed capacitance and lumped capacitance, it needs to be determined through experimental debugging.

[0180] To verify the correspondence between lumped capacitance and distributed capacitance, that is, the relationship between the capacitance C of the first capacitor C1 and the second capacitor C2 and the size of the gap G, this application provides an antenna structure, as shown in FIG30. The first radiator 0311 includes a first branch 11, which extends along the first direction y. The second radiator 0312 includes a second branch 12, which extends along the first direction y. The third radiator 0313 includes a third branch 13, which extends along the second direction x. The first branch 11 and the third branch 13 form the first capacitor C1 at the gap G, and the second branch 12 and the third branch 13 form the second capacitor C2 at the gap G. The first direction y and the second direction x are perpendicular.

[0181] Continuing as shown in Figure 30, antenna structure 03 also includes a first spring and a second spring. The first end of the first spring is electrically connected to the third stub 13, and the second end of the first spring serves as the first feed terminal 0341. The first end of the second spring is also electrically connected to the third stub 13, and the second end of the second spring serves as the second feed terminal 0342. In this way, antenna structure 03 can be fed through the first and second springs. Because the springs themselves have a certain self-adjusting capability, they can adapt to slight assembly errors. Therefore, using spring-feed simplifies the assembly process of antenna structure 03 and reduces the need for precise alignment. Furthermore, the spring connection method typically does not require complex disassembly or maintenance when replacement or maintenance is needed, making it easier to operate.

[0182] The embodiments of this application do not limit the form of the carrier plate 032. The carrier plate 032 can be any form capable of supporting the first radiator 0311 and the second radiator 0312. For example, the carrier plate can be a plastic plate, a flexible circuit board, or a printed circuit board.

[0183] This application does not limit the form of the gap G. The gap G can be a real gap or an insulating strip located between the carrier plate 032 and the circuit board 033. This application also does not limit the connection relationship between the carrier plate 032 and the circuit board 033. For example, the carrier plate 032 and the circuit board 033 can be integrated. For example, the carrier plate 032 and the circuit board 033 can be set independently. It is understood that when the gap is an insulating strip, the carrier plate 032 and the circuit board 033 are integrated.

[0184] Based on the example of the carrier plate 032 and the circuit board 033 being integrated, the electrical performance of the antenna structure 03 is simulated by taking the gap G as 0.5 mm, 1 mm and 1.5 mm in sequence.

[0185] Curves ①, ②, and ③ in Figures 31 (simulation results of return loss S11 of the antenna structure in Figure 30) and 32 (simulation results of isolation S21 of the antenna structure in Figure 30) correspond to the return loss and isolation of the antenna structure when the gap G is 0.5 mm, 1 mm, and 1.5 mm, respectively. It can be seen that when the gap G is 0.5 mm, the resonant point of the fundamental mode is or approximately 1.425 GHz; when the gap G is 1 mm, the resonant point of the fundamental mode is or approximately 1.562 GHz; and when the gap G is 1.5 mm, the resonant point of the fundamental mode is or approximately 1.643 GHz. The larger the gap G, that is, the smaller the capacitance C, the closer the frequency of the fundamental mode resonant point is to the frequency of the third-order mode resonant point.

[0186] For ease of marking in the attached figures, a gap G of 0.5 mm is denoted as G = 0.5 mm. The markings in other figures will not be repeated.

[0187] As shown in Figure 33 (simulation results of the Smith chart of the antenna structure in Figure 30), when the gap G is 0.5 mm, the closest points on the CM and DM impedance rings are points 1 and 4, corresponding to a frequency of 1.425 GHz; when the gap G is 1 mm, the closest points on the CM and DM impedance rings are points 2 and 5, corresponding to a frequency of 1.562 GHz; and when the gap G is 1.5 mm, the closest points on the CM and DM impedance rings are points 3 and 6, corresponding to a frequency of 1.643 GHz. Combining Figures 31 and 33, it can be seen that as the resonant point of the fundamental mode moves, the closest frequency points of the CM and DM impedances move synchronously.

[0188] Through further experimental analysis, it was ultimately determined that in the example where the carrier plate 032 and circuit board 033 are integrated, the antenna performance is optimal when the gap G is 0.8 mm. By replacing the first capacitor C1 and the second capacitor C2 with distributed capacitors, the antenna structure in the aforementioned embodiment can be divided into multiple radiators, some of which are placed on the circuit board 033 and some on the carrier plate 032. This reduces the clearance occupied by the antenna structure 03 on the circuit board 033. In other words, the antenna structure 03 provided in this application embodiment has a small clearance requirement, which can solve the problem of insufficient clearance on the circuit board 033 caused by the increase in the number of antennas, thus reducing the impact on the size of the electronic device.

[0189] Comparing Figures 3A and 30, the antenna structure 03 in Figure 3A also includes a ground plane 0330, with a third capacitor formed between the ground plane 0330 and the third stub 13. For example, the ground plane 0330 is a copper-clad area on the circuit board 033. Thus, by adjusting the capacitance value of the third capacitor, the common-mode impedance and differential-mode impedance of the antenna structure 03 can be adjusted. The smaller the difference between the common-mode impedance and the differential-mode impedance, the higher the isolation of the antenna. Optionally, the third capacitor can be implemented by adjusting the trace width of the third stub 13. In this case, the third capacitor is a distributed capacitor, which can reduce the number of lumped elements in the antenna structure 03 and simplify its structure.

[0190] Continuing to compare Figures 3A and 30, the antenna structure 03 in Figure 3A also includes a fourth stub 14, located between the first feed terminal 0341 and the second feed terminal 0342. The first end of the fourth stub 14 is electrically connected to the third stub 13, and a fourth capacitor is formed between the fourth stub 14 and the ground plane 0330. Thus, by adjusting the capacitance value of the fourth capacitor, the common-mode impedance and differential-mode impedance of the antenna structure 03 can be adjusted. The smaller the difference between the common-mode impedance and the differential-mode impedance, the higher the antenna isolation. Optionally, the fourth capacitor can be implemented by adjusting the trace width of the fourth stub. In this case, the fourth capacitor is a distributed capacitor, which can reduce the number of lumped elements in the antenna structure 03 and simplify its structure.

[0191] Continuing to compare Figures 3A and 30, in the antenna structure 03 of Figure 3A, the third radiator 0313 further includes a seventh stub 17 and an eighth stub 18. The first end of the seventh stub 17 is electrically connected to the third stub 13, and the second end of the seventh stub 17 serves as the first feed terminal 0341. The first end of the eighth stub 18 is electrically connected to the third stub 13, and the second end of the eighth stub 18 serves as the second feed terminal 0342. In this way, the antenna structure 03 can be fed through the seventh and eighth stubs.

[0192] Continuing to compare Figures 3A and 30, the antenna structure 03 in Figure 3A also includes a fifth capacitor C5 and a sixth capacitor C6. The fifth capacitor C5 is connected in series between the third stub 13 and the seventh stub 17; the sixth capacitor C6 is connected in series between the third stub 13 and the eighth stub 18. Thus, since the second end of the seventh stub 17 serves as the first feed terminal 0341 and the second end of the eighth stub 18 serves as the second feed terminal 0342, the fifth capacitor C5 and the sixth capacitor C6 are effectively connected in series near the feed terminals. By connecting capacitors in series near the feed terminals, the input impedance of the antenna can be changed. By adjusting the capacitance values ​​of the fifth capacitor C5 and the sixth capacitor C6, the input impedance can be made closer to the impedance required by the system (typically 50 ohms), thereby optimizing S11 and S22 and reducing reflections.

[0193] To improve the structural tolerance of the antenna structure during manufacturing, the coupling area between the first and third radiators, and the coupling area between the second and third radiators, can be increased.

[0194] In one possible implementation, as shown in FIG34, the first radiator 0311 includes a first branch 11 and a fifth branch 15, the first branch 11 extending along a first direction y, and the fifth branch 15 extending along a second direction x. One end of the fifth branch 15 is connected to the end of the first branch 11 facing the third branch 13. The second radiator 0312 includes a second branch 12 and a sixth branch 16, the second branch 12 extending along the first direction y, and the sixth branch 16 extending along the second direction x. One end of the sixth branch 16 is connected to the end of the second branch 12 facing the third branch 13. The fifth branch 15 and the sixth branch 16 are located between the first branch 11 and the second branch 12. In this way, the coupling area between the first radiator 0311 and the third radiator 0313 is increased from the coupling area between the first branch 11 and the third branch 13 to the coupling area between the first branch 11 plus the fifth branch 15 and the third branch 13. Similarly, the coupling area of ​​the second radiator 0312 and the third radiator 0313 also increased.

[0195] In one possible implementation, continuing as shown in Figure 34, the length L2 of the fifth stub is equal to the length L3 of the sixth stub, i.e., L2 = L3 = L. Based on this, the electrical performance of antenna structure 03 is simulated by successively taking L = 0 mm, L = 3 mm, L = 6 mm, and L = 9 mm. The simulation results of the return loss S11 are shown in Figure 35. It can be seen that the change of L can cause a change in the capacitance C of the first capacitor C1 and the second capacitor C2, thereby causing a change in the frequency of the first mode. When L is longer, C increases, and the resonant frequency of the first mode decreases. When L is shorter, C decreases, and the resonant frequency of the first mode increases.

[0196] In other words, the introduction of the fifth stub 15 and the sixth stub 16 can increase the coupling area of ​​the first radiator 0311 and the third radiator 0313. By adjusting the lengths of the fifth stub 15 and the sixth stub 16, the capacitance values ​​of the first capacitor C1 and the second capacitor C2 can be adjusted, thereby bringing the resonant frequency of the first mode closer to the resonant frequency of the second mode, thus expanding the bandwidth of the antenna structure 03.

[0197] In one possible implementation, as shown in Figure 34, L = 9 mm. The electrical performance of antenna structure 03 is simulated. The simulation results for return loss S11 are shown in Figure 36, the simulation results for antenna efficiency are shown in Figure 37, and the antenna gain pattern is shown in Figure 38.

[0198] Since the lengths of the fifth stub 15 and the sixth stub 16 are equal, the lengths of the first stub 11 and the second stub 12 are equal, and the capacitance values ​​of the first capacitor C1 and the second capacitor C2 are equal, the return loss curves, isolation curves, and efficiency curves of the first antenna element and the second antenna element coincide. Therefore, in Figures 36 and 37, only the electrical performance curve of one antenna element needs to be presented. For example, Figures 36 and 37 present the electrical performance curve of the first antenna element.

[0199] As shown in Figure 36, within the 1.427GHz to 2.69GHz frequency band, the return loss curves of the antenna structure are all below -6dB, and the isolation curves are all around -15dB. This means that the antenna structure's operating frequency band can cover the entire LTE middle high band (MHB), i.e., the 1.427GHz to 2.69GHz band, with good in-band isolation.

[0200] In Figure 37, the antenna structure exhibits a radiation efficiency within -0.5 dB in the 1.427 GHz to 2.69 GHz frequency band, with an overall efficiency within -1.5 dB. In Figure 38, the first antenna element ant-1 maintains good in-band radiation patterns in both the first and second modes, and the second antenna element ant-2 also maintains good in-band radiation patterns in both modes. Therefore, the antenna structure 03 provided in this embodiment meets the application requirements of the CPE product in the MHB band.

[0201] Radiation efficiency refers to the ratio of antenna gain to directivity, or the ratio of radiated power to received power. Total efficiency, also known as system efficiency, is the ratio of radiated power to input signal power. Both efficiencies are used to measure an antenna's radiation capability and are generally expressed as a percentage. There is a conversion relationship between percentage and dB; the closer the efficiency is to 0 dB, the better the antenna's performance.

[0202] Gain is a parameter describing the degree to which an antenna concentrates the radiated input power; that is, it describes the radiation effect in the direction of maximum radiation. A high-gain antenna can increase the radiated power in a specific direction while keeping the input power constant.

[0203] This application does not limit the positional relationship between the carrier plate 032 and the circuit board 033. As shown in FIG39A, the carrier plate 032 and the circuit board 033 may have a gap G and an included angle α. In some embodiments, the carrier plate 032 may be arranged parallel to the circuit board 033 (the included angle α is 180 degrees). For example, the carrier plate 032 and the circuit board 033 are disposed on the same plane and are connected as one piece.

[0204] In some embodiments, the carrier plate 032 can be positioned at an angle α greater than 0 degrees and less than 180 degrees with the circuit board 033. This increases the adaptability of the antenna structure 03, allowing it to be used in various spatial arrangements in practical applications. For example, the mounting space may only be able to accommodate the circuit board 033 in the third direction z, but there is still considerable space in the fourth direction where the angle with the xy plane is between 0 degrees and 180 degrees. In this case, the circuit board 033 and the carrier plate 032 can be arranged intersectingly within the mounting space. For example, the carrier plate 032 and the circuit board 033 can be arranged intersectingly at an angle of 10 degrees, 20 degrees, 30 degrees, 40 degrees, 50 degrees, 60 degrees, 70 degrees, or 80 degrees. It should be understood that the size of this angle is related to the size of the mounting space in the actual application, and not all examples can be exhaustively listed.

[0205] As shown in Figures 39B and 40, this is another implementation of antenna structure 03 in Figure 34. The carrier plate 032 and circuit board 033 are intersected at a 90-degree angle, meaning they are perpendicular. For practical production, the gap G is taken as 2.5 mm (hereinafter referred to as the "typical value"). Based on this, considering that there will be certain assembly tolerances during the actual product assembly process, which will cause changes in the gap G between the carrier plate 032 and circuit board 033, a simulation analysis is conducted to analyze the impact of assembly tolerances on the antenna structure.

[0206] As shown in Figure 41 (a simulation diagram of the influence of antenna structure assembly tolerance on scattering parameters shown in Figure 40), taking the scattering parameters at 1.427 GHz as an example, points 1 and 4 represent the scattering parameters with the largest downward deviation of the tolerance (gap G = 2.2 mm), points 2 and 5 represent the typical values ​​of the scattering parameters (gap G = 2.5 mm), and points 3 and 6 represent the scattering parameters with the largest upward deviation of the tolerance (gap G = 2.8 mm). As shown in Figure 42 (a simulation diagram of the influence of antenna structure assembly tolerance on efficiency shown in Figure 40), taking the scattering parameters at 1.427 GHz as an example, point 1 represents the total efficiency with the largest downward deviation of the tolerance (gap G = 2.2 mm), point 2 represents the total efficiency with the typical value (gap G = 2.5 mm), and point 3 represents the total efficiency with the largest upward deviation of the tolerance (gap G = 2.8 mm). Within the tolerance range, the changes in S11, S21, and efficiency are all linearly related to the change in gap, and all are close to the ideal range. The ideal range refers to S11 < -6dB, S21 < -15dB, and overall efficiency > -1.5dB. It can be seen that within a tolerance range of 2.5 ± 0.3 mm, the antenna structure performance does not fluctuate significantly and can meet the requirements of product applications.

[0207] In some embodiments, as shown in FIG43, another implementation of the third radiator of the antenna structure in FIG39B is presented. A ground plane is laid around the third radiator on the circuit board 033. This reduces the net space occupied by the third radiator 0313 on the circuit board 033, freeing up more space for other components on the circuit board 033, thus facilitating the miniaturization design of electronic devices.

[0208] Furthermore, in actual manufacturing, the third radiator 0313 of the antenna structure 03 shown in Figure 43 can be fabricated by creating a slot on the circuit board 033. This alters the current distribution on the circuit board, allowing for more diverse antenna feed design and adaptability to various PCB environments. Based on this, the electrical performance of the antenna structure shown in Figure 43 is simulated and analyzed. As shown in Figure 44 (simulation diagram of scattering parameters of the antenna structure shown in Figure 43), the return loss curves of the antenna are all below -6dB, and the isolation curves are all near -15dB. As shown in Figure 45 (simulation diagram of efficiency of the antenna structure shown in Figure 43), the radiation efficiency of the antenna structure in the 1.427GHz to 2.69GHz frequency band is -0.5dB, and the total efficiency is within -1.5dB. As shown in Figure 46 (gain pattern of the antenna structure shown in Figure 43), the first antenna element ant-1 maintains good in-band pattern fidelity in both the first and second modes, and the second antenna element ant-2 also maintains good in-band pattern fidelity in both the first and second modes. Comparing Figure 46 and Figure 38, the gain pattern of the antenna structure does not change much after the ground plane is filled in.

[0209] Based on this, a simulation analysis was conducted on the impact of assembly tolerances on the antenna structure. As shown in Figure 47 (simulation diagram of the impact of antenna structure assembly tolerances on scattering parameters as shown in Figure 43), taking the scattering parameters at 1.427 GHz as an example, points 1 and 4 represent the scattering parameters with the largest downward deviation of the tolerance (gap G = 2.2 mm), points 2 and 5 represent the typical values ​​of the scattering parameters (gap G = 2.5 mm), and points 3 and 6 represent the scattering parameters with the largest upward deviation of the tolerance (gap G = 2.8 mm). As shown in Figure 48 (simulation diagram of the impact of antenna structure assembly tolerances on efficiency as shown in Figure 45), taking the scattering parameters at 1.427 GHz as an example, point 1 represents the total efficiency with the largest downward deviation of the tolerance (gap G = 2.2 mm), point 2 represents the total efficiency with the typical value (gap G = 2.5 mm), and point 3 represents the total efficiency with the largest upward deviation of the tolerance (gap G = 2.8 mm). Within the tolerance range, the changes in S11, S21, and efficiency are all linearly related to the change in gap, and all are close to the ideal range. The ideal range refers to S11 < -6dB, S21 < -15dB, and overall efficiency > -1.5dB. Comparing Figures 47 and 41, and 48 and 42, after grounding, the antenna's S11, S21, and overall efficiency do not change significantly within the tolerance range. It can be seen that within a tolerance range of 2.5 ± 0.3 mm, the antenna structural performance does not fluctuate significantly and can meet the product application requirements.

[0210] This application also provides an electronic device. In one possible implementation, as shown in FIG49, the electronic device 01 includes a first housing 011, a circuit board assembly 02, and any of the antenna structures described above. At least a portion of the first housing 011 can be reused as a carrier plate for the antenna structure 03. The first housing 011 has a receiving cavity, and the antenna structure 03 is located within the receiving cavity. For example, the circuit board of the circuit board assembly 02 is reused as the circuit board of the antenna structure 03, and the antenna structure 03 is disposed on the circuit board assembly 02. In this way, a portion of the traces of the antenna structure 03 are disposed on the first housing 011, and another portion is disposed on the circuit board assembly 02. The traces on the first housing 011 and the traces on the circuit board assembly 02 are coupled by a gap G capacitor, thereby reducing the clearance requirement of the antenna structure and mitigating the contradiction between increasing communication specifications and miniaturizing electronic devices.

[0211] In another possible implementation, as shown in FIG50, the electronic device 01 includes a first housing 011, a second housing 012, and any of the antenna structures described above. The first housing 011 has a receiving cavity, and the second housing 012 and the antenna structure 03 are located within the receiving cavity. At least a portion of the second housing 012 can be reused as a carrier plate for the antenna structure 03. The included angle between the carrier plate and the circuit board is 90 degrees. This mitigates the conflict between increasing communication specifications and miniaturizing the electronic device.

[0212] In another possible implementation, as shown in FIG51, the electronic device 01 includes a first housing 011, a second housing 012, and any of the antenna structures described above. The first housing 011 has a receiving cavity, and the second housing 012 and the antenna structure 03 are located within the receiving cavity. At least a portion of the second housing 012 can be reused as a carrier plate for the antenna structure 03. The angle between the carrier plate and the circuit board is greater than 0 degrees and less than or equal to 180 degrees, depending specifically on the angle design of the second housing itself.

[0213] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples. The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions within the technical scope disclosed in this application should be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An antenna structure, characterized by include: A radiator assembly includes a first radiator and a second radiator spaced apart, and a third radiator; The third radiator has a first feed terminal and a second feed terminal. A support plate that supports the first radiator and the second radiator; A circuit board that carries the third radiator; the circuit board has a first electrical connection terminal and a second electrical connection terminal; the first electrical connection terminal is coupled to the first power supply terminal, and the second electrical connection terminal is coupled to the second power supply terminal; There is a gap between the circuit board and the carrier plate; the first radiator and the third radiator form a first capacitor at the gap position, and the second radiator and the third radiator form a second capacitor at the gap position.

2. The antenna structure of claim 1, wherein, The operating frequency band of the antenna structure includes a first sub-band and a second sub-band; The first sub-band includes a first minimum value and a first maximum value; the second sub-band includes a second minimum value and a second maximum value; The first maximum value is the same as the second minimum value; or; The second minimum value is greater than the first minimum value and less than the first maximum value; the second maximum value is greater than the first maximum value.

3. The antenna structure according to claim 1 or 2, characterized in that, The radiator assembly is used to generate a first resonance in a first sub-band when operating in a first mode; the radiator assembly is used to generate a second resonance in a second sub-band when operating in a second mode. Both the first capacitor and the second capacitor are located at the zero current point when the radiator assembly is operating in the second mode.

4. The antenna structure of claim 3, wherein, The capacitance of the first capacitor is equal to the capacitance of the second capacitor.

5. The antenna structure of claim 3 or 4, characterized in that The first mode is the fundamental mode of the radiator assembly, and the second mode is the cubic mode of the radiator assembly.

6. The antenna structure of any of claims 1-5, wherein, There is a first gap D1 between the first feed terminal and the second feed terminal, and the electrical length of the first gap D1 is greater than or equal to 0.1λ and less than or equal to 0.5λ; where λ is the operating wavelength of the first mode.

7. The antenna structure according to claim 6, characterized in that, There is a first gap D1 between the first power supply terminal and the second power supply terminal, and the physical length of the first gap D1 is greater than or equal to 20mm and less than or equal to 60mm.

8. The antenna structure of any of claims 1-7, wherein, The first radiator and the second radiator have a second spacing D2, the electrical length of the second spacing D2 being greater than or equal to 0.3λ; where λ is the operating wavelength of the first mode.

9. The antenna structure according to claim 8, characterized in that, The first radiator and the second radiator have a second spacing D2, and the physical length of the second spacing D2 is greater than or equal to 60 mm.

10. The antenna structure according to any one of claims 1-9, characterized in that, The first radiator includes a first branch that extends along a first direction; The second radiator includes a second branch that extends along a first direction; The third radiator includes a third branch extending along a second direction; the first branch and the third branch form a first capacitor at the gap position, and the second branch and the third branch form a second capacitor at the gap position; Wherein, the first direction and the second direction are perpendicular.

11. The antenna structure according to claim 10, characterized in that, The antenna structure also includes a ground plane; a third capacitor is formed between the ground plane and the third branch.

12. The antenna structure according to claim 10 or 11, characterized in that, The third radiator further includes a fourth branch, which is located between the first feed terminal and the second feed terminal; the first end of the fourth branch is electrically connected to the third branch, and a fourth capacitor is formed between the fourth branch and the floor.

13. The antenna structure according to any one of claims 10-12, characterized in that, The first radiator includes a first branch and a fifth branch, the first branch extending along a first direction and the fifth branch extending along a second direction; one end of the fifth branch is connected to the end of the first branch facing the third branch; The second radiator includes a second branch and a sixth branch, the second branch extending along a first direction; The sixth branch extends along the second direction; one end of the sixth branch is connected to the end of the second branch facing the third branch; The fifth and sixth branches are located between the first and second branches.

14. The antenna structure of any of claims 10-13, wherein, The third radiator also includes: The seventh branch has its first end electrically connected to the third branch, and its second end serves as the first power supply end. The eighth branch has its first end electrically connected to the third branch, and its second end serves as the second power supply terminal.

15. The antenna structure of any of claims 10-14, wherein, The third radiator also includes a fifth capacitor and a sixth capacitor; The fifth capacitor is connected in series between the third branch and the seventh branch; the sixth capacitor is connected in series between the third branch and the eighth branch.

16. The antenna structure of any of claims 1-15, wherein, The carrier plate and the circuit board are arranged crosswise.

17. An electronic device, comprising: The device includes a first housing and an antenna structure as described in any one of claims 1-16; at least a portion of the first housing can be reused as a carrier plate for the antenna structure; the first housing has a receiving cavity, and the antenna structure is located within the receiving cavity.

18. An electronic device, comprising: The antenna includes a first housing, a second housing, and an antenna structure as described in any one of claims 1-16; the first housing has a receiving cavity, the second housing and the antenna structure are located within the receiving cavity; at least a portion of the second housing can be reused as a support plate for the antenna structure.

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