An antenna device, a circuit board assembly, and an electronic device

Abstract

This application provides an antenna device, a circuit board assembly, and an electronic device to improve the problem of pattern nulls in the radiation pattern of an antenna structure and enhance the transmission performance of the antenna device. The antenna device may include a circuit board, a cable, and an antenna structure. Along a first direction, the circuit board includes a first end and a second end, with the cable connected to the first end of the circuit board and the antenna structure connected to the second end of the circuit board. The antenna structure includes a first radiator and a second radiator arranged along a second direction, which intersects the first direction. The first radiator has a first feed end for receiving a first feed signal. The second radiator has a second feed end for receiving a second feed signal. The first and second feed signals are used to adjust the non-circularity R of the antenna structure's radiation pattern, such that R ≤ 10dB.

Description

Technical Field

[0001] This application relates to the field of antennas, and more particularly to an antenna device, a circuit board assembly, and an electronic device. Background Technology

[0002] Antennas, as key components of intelligent connected systems such as wireless communication, wireless networks, and satellite positioning, play a crucial role in transmitting and receiving signals in wireless communication systems. The radiation capability of an antenna varies at different angles; some angles have stronger radiation capability, while others have weaker radiation capability. The stronger the antenna's radiation (e.g., transmission or reception) capability at a given angle, the higher its gain. Conversely, the weaker the antenna's radiation capability at a given angle, the lower its gain. The spatial distribution of an antenna's radiation capability can be identified by a radiation pattern (or gain pattern). Angles where the gain is much lower than the maximum gain can be called "pattern nulls."

[0003] With the rapid development of automobiles towards intelligence, autonomous driving, and the Internet of Things, the demands on antennas in next-generation smart cars are increasing. In existing vehicles, the antenna pattern exhibits null points at certain angles, leading to unstable signal reception. For example, in digital car key systems using Bluetooth Low Energy Received Signal Strength Indicator (BLE RSSI) for ranging, signal instability can cause unlocking or deactivation failures, resulting in a poor user experience. Therefore, improving the handling of null points is a pressing issue that needs to be addressed. Utility Model Content

[0004] This application provides an antenna device, a circuit board assembly, and an electronic device, which improves the problem of pattern nulls in the radiation pattern of the antenna device, thereby enhancing the transmission performance of the antenna device.

[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 device, which may include a circuit board, a cable, and an antenna structure. Along a first direction, the circuit board includes a first end and a second end, the cable is connected to the first end of the circuit board, and the antenna structure is connected to the second end of the circuit board. The antenna structure includes a first radiator and a second radiator arranged along a second direction, the first and second directions intersecting. The first radiator has a first feed end for receiving a first feed signal. The second radiator has a second feed end for receiving a second feed signal. At least one of the first and second feed signals is used to adjust the non-circularity R of the antenna structure's radiation pattern, such that R ≤ 10 dB.

[0007] In the antenna device provided in this application embodiment, along a first direction, the circuit board includes a first end and a second end, and the antenna structure is connected to the second end of the circuit board. The antenna structure includes a first radiator and a second radiator arranged along a second direction, with the first and second directions intersecting. In the operating state of the antenna structure, current is generated on the first and second radiators. This current can induce a current on the circuit board, which can then excite an electromagnetic field and form a surface wave on the circuit board. A cable is connected to the first end of the antenna structure. The component of the surface wave along the first direction can be transmitted to the first end and continue to propagate along the cable, causing electromagnetic coupling between the circuit board and the cable. This electromagnetic coupling interferes with the original electrical signal between the circuit board and the cable, potentially causing distortion of the original electrical signal and resulting in a zero point in the radiation pattern of the antenna structure. The intersection of the first and second directions reduces the component of the induced current in the first direction, thereby reducing the electromagnetic coupling between the circuit board and the cable and improving the zero point problem in the radiation pattern of the antenna device. The first feed terminal of the first radiator is used to receive the first feed signal, and the second feed terminal of the second radiator is used to receive the second feed signal. By adjusting at least one of the first or second feed signals, the non-circularity R of the antenna pattern can be adjusted so that R ≤ 10dB. The closer the non-circularity of the pattern is to 0, the smaller the difference between the maximum and minimum gain on the pattern, resulting in fewer null points on the antenna pattern and improving the null point problem of the antenna device.

[0008] In one possible implementation, the cable may include at least one of signal lines, control lines, input leads, or output leads. In this case, connecting one end of the cable to the circuit board, such as connecting the cable to the first end of the circuit board, facilitates interface debugging or testing. During operation, signal lines, control lines, input leads, or output leads, due to their physical length and electrical characteristics, can act as antennas to receive or transmit electromagnetic waves. Therefore, the original electrical signals transmitted between the cable and the circuit board will be subject to interference from surface waves.

[0009] In some embodiments, the physical lengths of the first radiator and the second radiator are equal. The first radiator includes opposing first and second electrical connection terminals, with a first feed terminal disposed at the second electrical connection terminal. The second radiator includes opposing third and fourth electrical connection terminals, with a second feed terminal disposed at the third electrical connection terminal. The second electrical connection terminal is closer to the third electrical connection terminal relative to the first electrical connection terminal. The third electrical connection terminal is closer to the second electrical connection terminal relative to the fourth electrical connection terminal. In this case, the current amplitude on the first radiator decreases along the direction from the second electrical connection terminal to the first electrical connection terminal. The current amplitude on the second radiator decreases along the direction from the third electrical connection terminal to the fourth electrical connection terminal. The similarity in the current distribution on the first and second radiators helps the antenna structure form a more symmetrical radiation pattern, thereby enabling electronic devices using this antenna device to provide more uniform signal coverage.

[0010] In one possible implementation, a first gap exists between the second electrical connection terminal and the third electrical connection terminal. This is a relatively simple implementation of an antenna structure.

[0011] In one possible implementation, the second electrical connection terminal is connected to the third electrical connection terminal. In this case, the portion of the conductor between the first and second feed terminals can be considered as an equivalent load. The physical length of this portion of the conductor can determine the load value, and a suitable load value allows the antenna structure to achieve good impedance matching.

[0012] In one possible implementation, a second gap exists between the first electrical connection terminal and the fourth electrical connection terminal. This is a relatively simple implementation of an antenna structure.

[0013] In one possible implementation, the first electrical connection is connected to the fourth electrical connection. The voltages of the first feed signal and the second feed signal are different. In this case, the first feed signal can be transmitted to the second radiator through the fourth electrical connection, and the second feed signal can be transmitted to the first radiator through the first feed connection. The superposition of the first and second feed signals can increase the input impedance of the antenna structure, thereby making it easier to achieve impedance matching. In some examples, the antenna structure includes a folded dipole.

[0014] In some embodiments, the first radiator is strip-shaped and extends along a second direction. The second radiator is also strip-shaped and extends along the second direction. In this case, the first feed terminal of the first radiator receives a first feed signal and generates a first current parallel to the second direction on the first radiator. The first current induces a third current parallel to the second direction on the circuit board, and the first and third currents are in opposite directions. The second feed terminal of the second radiator receives a second feed signal and generates a second current parallel to the second direction on the second radiator. The second current induces a fourth current parallel to the second direction on the circuit board, and the second and fourth currents are in opposite directions. Because the first and second directions intersect, the component of the third current along the first direction weakens, and the component of the fourth current along the first direction weakens, thereby weakening the surface waves excited by the third current and the surface waves excited by the fourth current. As the surface waves excited by the induced current (the third or fourth current) weaken, the energy that these surface waves can transmit to the cable also weakens. The electromagnetic coupling between the circuit board and the cable weakens, which can improve the interference between this electromagnetic coupling and the original electrical signal between the circuit board and the cable, improve the problem of the original electrical signal distortion, and thus improve the problem of the zero point on the radiation pattern of the antenna device.

[0015] In one possible implementation, the first direction is perpendicular to the second direction. In this case, the surface wave component along the first direction can theoretically be zero, thereby further improving the problem of null points in the antenna pattern. Furthermore, since the antenna structure is located at the first end of the circuit board, and the first and second radiators are arranged along the second direction, the perpendicularity of the first and second directions can save space on the circuit board.

[0016] In some embodiments, the first radiator includes a first stub extending along a first direction. The second radiator includes a second stub extending along the first direction. The voltages of the first feed signal and the second feed signal are different. In this case, the first feed terminal of the first radiator receives the first feed signal and generates a first current parallel to the first direction on the first stub. The first current induces a third current parallel to the first direction on the circuit board, and the first and third currents are in opposite directions. The second feed terminal of the second radiator receives the second feed signal and generates a second current parallel to the first direction on the second radiator. The second current induces a fourth current parallel to the first direction on the circuit board, and the second and fourth currents are in opposite directions. Because the voltages of the first and second feed signals are different, the first and second currents are in opposite directions, and the third and fourth currents are in opposite directions. Thus, the third and fourth currents can at least partially cancel each other out, reducing the induced current (third or fourth current) on the circuit board of the antenna structure. This reduces the surface waves excited by the induced current, and can also improve the problem of nulls in the radiation pattern of the antenna device.

[0017] In one possible implementation, the first feed signal and the second feed signal have equal amplitudes but opposite phases. That is, the first feed signal and the second feed signal are a pair of differential signals. In this case, the first current and the second current have equal amplitudes but opposite phases. The third current induced by the first current and the fourth current induced by the second current also have similar amplitudes but opposite directions. The third current and the fourth current can cancel out more components, thereby further improving the problem of nulls in the antenna pattern.

[0018] In one possible implementation, one of the first and second feed signals has a voltage of zero, while the other has a high voltage level. For example, one of the first and second feed terminals is grounded, and the other is connected to the feed source. In this case, the voltage difference between the first and second feed signals can produce an effect similar to a differential signal, making the amplitudes of the first and second currents equal but their phases opposite. The beneficial effects are as described above and will not be repeated.

[0019] In one possible implementation, the first radiator further includes a third branch extending along the second direction. The end of the first branch opposite to the third branch is a first electrical connection terminal, and the end of the third branch opposite to the first branch is a second electrical connection terminal. The second radiator further includes a fourth branch extending along the second direction. The end of the second branch opposite to the fourth branch is a fourth electrical connection terminal, and the end of the fourth branch opposite to the second branch is a third electrical connection terminal. In this case, it facilitates the connection of the first and second radiators to the feed source. In some examples, the third electrical connection terminal is connected to the fourth electrical connection terminal, i.e., the third branch and the fourth branch are connected, with the same advantages as described above.

[0020] In some embodiments, the antenna structure includes a fifth stub, a sixth stub, and a seventh stub. The fifth stub extends along a first direction, and the sixth stub also extends along the first direction. One end of the fifth stub is connected to a second electrical connection terminal, one end of the sixth stub is connected to a third electrical connection terminal, one end of the seventh stub is connected to the other end of the fifth stub, and the other end of the seventh stub is connected to the other end of the sixth stub. In this case, the second electrical connection terminal and the third electrical connection terminal are connected via the fifth, sixth, and seventh stubs, providing the same advantages as described above.

[0021] A second aspect of this application provides a circuit board assembly for electrical connection to an antenna structure. The circuit board assembly may include a circuit board, a cable, and a choke device. Along a first direction, the circuit board includes a first end and a second end, the cable is connected to the first end of the circuit board, and the choke device is electrically connected between the circuit board and the cable. In this case, the choke device can suppress the influence of the induced current generated on the circuit board by the antenna structure on the cable, thereby improving the interference between the induced current and the original electrical signal between the circuit board and the cable, improving the problem of original electrical signal distortion, and further improving the problem of null points in the radiation pattern of the antenna device composed of the antenna structure and the circuit board assembly.

[0022] In one possible implementation, the choke device includes at least one of a capacitor or an inductor. When the choke device is an inductor, the original electrical signal between the circuit board and the cable can pass normally, and high-frequency interference generated by induced current is effectively suppressed. When the choke device is a capacitor, the original electrical signal between the circuit board and the cable can pass normally, and low-frequency interference generated by induced current is effectively suppressed.

[0023] In some embodiments, the circuit board includes a first cutout area, wherein the vertical projection of the cable on the circuit board at least partially overlaps with the first cutout area. In this case, the probability of electromagnetic coupling between the cable and the circuit board can be reduced, thereby improving the interference between the induced current and the original electrical signal between the circuit board and the cable, improving the problem of original electrical signal distortion, and thus improving the problem of null point in the radiation pattern of the antenna device.

[0024] In some embodiments, the circuit board includes a second cutout area, the vertical projection of the antenna structure onto the circuit board at least partially overlapping the second cutout area. In this case, the probability of the antenna structure generating induced current on the circuit board can be reduced, thereby improving the interference between the induced current and the original electrical signal between the circuit board and the cable, improving the problem of original electrical signal distortion, and thus improving the problem of null point in the radiation pattern of the antenna device.

[0025] In some embodiments, the circuit board includes a third cutout region with an electrical length of λ / 4. The antenna structure has a feed terminal, and the electrical distance between the third cutout region and the feed terminal is less than λ / 4. Here, λ is the operating wavelength of the antenna structure. In this case, the wavelength corresponding to the frequency of the induced current is also λ. Therefore, the third cutout region can suppress the induced current, thereby improving the interference between the induced current and the original electrical signal between the circuit board and the cable, improving the problem of original electrical signal distortion, and thus improving the problem of null point in the radiation pattern of the antenna device.

[0026] A third aspect of this application provides an electronic device that may include a housing and an antenna device of any type provided in the first aspect of this application, or a circuit board assembly of any type provided in the second aspect of this application, wherein the antenna device or circuit board assembly is disposed inside the housing. The beneficial effects of this electronic device are the same as those of the antenna device or circuit board assembly included in the electronic device, and will not be repeated here.

[0027] In some embodiments, the electronic device includes five antenna devices, namely a first antenna device, a second antenna device, a third antenna device, a fourth antenna device, and a fifth antenna device. The second, third, fourth, and fifth antenna devices are arranged around the first antenna device. In this case, the first, second, third, fourth, and fifth antenna devices can complement each other, reducing signal obstruction or attenuation caused by other structural components in the electronic device.

[0028] In one possible implementation, the electronic device may include a smart car, and the antenna devices may be used in a digital car key system. In this case, a first antenna device located in the center can be used to receive signals from inside the vehicle to detect whether the car key is inside the vehicle, while a second, third, fourth, and fifth antenna device located on the periphery can receive signals from all around the electronic device, thereby achieving omnidirectional signal reception and transmission and ensuring the operational stability of the digital car key system. Attached Figure Description

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

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

[0031] Figure 3 A schematic diagram of the structure of an antenna device provided for related technologies;

[0032] Figure 4 for Figure 3The radiation pattern of the antenna structure of the antenna device in the middle;

[0033] Figure 5 for Figure 3 Radiation pattern of the antenna device;

[0034] Figure 6 for Figure 4 and Figure 5 The cross-sectional view of the radiation pattern in the YZ plane, curve ① is Figure 4 The cross-sectional view of the radiation pattern in the YZ plane, curve ② is Figure 5 A cross-sectional view of the orientation pattern in the YZ plane;

[0035] Figure 7 for Figure 3 A simulation diagram of the current amplitude of an antenna device, in which the antenna structure operates independently;

[0036] Figure 8 for Figure 3 Another simulation diagram of the current amplitude of the antenna device, in which the antenna structure and cables are working simultaneously;

[0037] Figure 9A for Figure 3 Another simulation diagram of the current amplitude of the antenna device;

[0038] Figure 9B for Figure 3 A simulation diagram of the current direction of a medium-sized antenna device;

[0039] Figure 10 This is a schematic diagram of the structure of an antenna device provided in an embodiment of this application;

[0040] Figure 11 for Figure 10 A cross-sectional view of the radiation pattern of the antenna device on the YZ plane;

[0041] Figure 12 This is a schematic diagram of another antenna device provided in an embodiment of this application;

[0042] Figure 13 for Figure 12 A cross-sectional view of the radiation pattern of the antenna device on the YZ plane;

[0043] Figure 14 This is a schematic diagram of another antenna device provided in an embodiment of this application;

[0044] Figure 15A for Figure 14 A simulation diagram of the current amplitude of a medium-voltage antenna device.

[0045] Figure 15B for Figure 14 A cross-sectional view of the radiation pattern of the antenna device on the YZ plane;

[0046] Figure 16 This is a schematic diagram of another antenna device provided in an embodiment of this application;

[0047] Figure 17 for Figure 16 A simulation diagram of the current amplitude of a medium-voltage antenna device;

[0048] Figure 18 for Figure 16 A simulation diagram of the current direction of a medium-sized antenna device;

[0049] Figure 19 for Figure 16 A cross-sectional view of the radiation pattern of the antenna device on the YZ plane;

[0050] Figure 20 This is a schematic diagram of another antenna device provided in an embodiment of this application;

[0051] Figure 21 This is a schematic diagram of another antenna device provided in an embodiment of this application;

[0052] Figure 22 for Figure 20 A simulation diagram of the current amplitude of a medium-voltage antenna device;

[0053] Figure 23 for Figure 20 A simulation diagram of the current direction of a medium-sized antenna device;

[0054] Figure 24 for Figure 20 A cross-sectional view of the radiation pattern of the antenna device on the YZ plane;

[0055] Figure 25 This is a schematic diagram of another antenna device provided in an embodiment of this application;

[0056] Figure 26 This is a schematic diagram of another antenna device provided in an embodiment of this application;

[0057] Figure 27 This is a schematic diagram of another antenna device provided in an embodiment of this application;

[0058] Figure 28 for Figure 25 A simulation diagram of the current amplitude of a medium-voltage antenna device;

[0059] Figure 29 for Figure 26 A simulation diagram of the current amplitude of a medium-voltage antenna device;

[0060] Figure 30 for Figure 27A simulation diagram of the current amplitude of a medium-voltage antenna device;

[0061] Figure 31 for Figure 25 , Figure 26 and Figure 27 The orientation pattern in the YZ plane interface, curve ① is... Figure 25 The cross-sectional view of the radiation pattern in the YZ plane, curve ② is Figure 26 The cross-sectional view of the radiation pattern in the YZ plane, curve ③ is Figure 25 The cross-sectional view of the orientation pattern in the YZ plane;

[0062] Figure 32 This is a schematic diagram of another antenna device provided in an embodiment of this application;

[0063] Figure 33 for Figure 32 A simulation diagram of the current amplitude of a medium-voltage antenna device;

[0064] Figure 34 for Figure 32 A simulation diagram of the current direction of a medium-sized antenna device;

[0065] Figure 35 This is a schematic diagram of another antenna device provided in an embodiment of this application;

[0066] Figure 36 Schematic diagrams of several antenna structures provided in the embodiments of this application;

[0067] Figure 37 for Figure 35 A schematic diagram of the current direction of a medium-voltage antenna device, wherein the voltages of the first feed signal and the second feed signal are different;

[0068] Figure 38 for Figure 37 Simulation diagram of current amplitude of the antenna device;

[0069] Figure 39 This is a schematic diagram of a power supply circuit provided in an embodiment of this application;

[0070] Figure 40 for Figure 35 Another schematic diagram of the current direction of the antenna device, where the voltages of the first feed signal and the second feed signal are the same;

[0071] Figure 41 This is a schematic diagram of another antenna device provided in an embodiment of this application;

[0072] Figure 42 for Figure 41 A schematic diagram of the current direction in a medium-sized antenna device;

[0073] Figure 43 This is a schematic diagram of another antenna device provided in an embodiment of this application;

[0074] Figure 44 for Figure 43 A schematic diagram of the current direction in a medium-sized antenna device;

[0075] Figure 45 for Figure 43 Another schematic diagram of the current direction of the antenna device;

[0076] Figure 46 for Figure 43 Simulation diagram of current amplitude of the antenna device;

[0077] Figure 47 for Figure 43 Radiation pattern of the antenna device;

[0078] Figure 48 for Figure 47 A cross-sectional view of the orientation pattern in the YZ plane;

[0079] Figure 49 for Figure 43 Simulation diagram of electrical parameters of the antenna device;

[0080] Figure 50 This is a schematic diagram of another antenna device provided in an embodiment of this application;

[0081] Figure 51 Figure 50 A schematic diagram of the current direction in a medium-sized antenna device;

[0082] Figure 52 for Figure 50 Simulation diagram of current amplitude of the antenna device;

[0083] Figure 53 for Figure 50 Radiation pattern of the antenna device;

[0084] Figure 54 for Figure 50 A cross-sectional view of the radiation pattern of the antenna device on the YZ plane;

[0085] Figure 55 for Figure 50 Simulation diagram of electrical parameters of the antenna device;

[0086] Figure 56 This is a schematic diagram of another antenna device provided in an embodiment of this application;

[0087] Figure 57 This is a schematic diagram of another antenna device provided in an embodiment of this application;

[0088] Figure 58This is a schematic diagram of another antenna device provided in an embodiment of this application;

[0089] Figure 59 A schematic diagram of another antenna device provided in the embodiments of this application.

[0090] Figure 60 This is a schematic diagram of another antenna device provided in an embodiment of this application. Detailed Implementation

[0091] 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.

[0092] Hereinafter, 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 indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of embodiments of this application, unless otherwise stated, "a plurality of" means two or more.

[0093] 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.

[0094] The technical solutions provided in this application are applicable to electronic devices employing one or more of the following communication technologies: Bluetooth (BT) communication technology, Global Positioning System (GPS) communication technology, Wireless Fidelity (WiFi) communication technology, Global System for Mobile Communications (GSM) communication technology, Wideband Code Division Multiple Access (WCDMA) communication technology, Long Term Evolution (LTE) communication technology, 5G communication technology, and other future communication technologies.

[0095] Depending on the type of communication protocol, electronic devices can perform terrestrial network (TN) communication, satellite communication, or satellite positioning. Examples include... Figure 1As shown, ground network communication can include cellular communication between electronic devices and base stations. The frequency bands of the cellular communication radio frequency signals used in cellular communication can include low band (LB), such as 300MHz to 1024MHz, middle high band (MHB), such as 1800MHz-2700MHz, and the 5G new radio (NR) band.

[0096] Or, continue as Figure 1 As shown, and exemplified by another example, ground network communication can include short-range communication between electronic devices and nearby devices such as routers or other electronic devices. Short-range communication can include: wireless fidelity (WiFi) communication, Bluetooth (BT) communication, Bluetooth Low Energy (BLE) communication, Near Link communication, SparkLink Low Energy (SLE) communication, location-based services (LBS) communication, near-field communication (NFC), radio frequency identification (RFID) communication, Zigbee protocol, etc.

[0097] Continue as Figure 1 As shown, satellite communication between electronic devices and satellites can be classified as nonterrestrial network (NTN) communication, i.e., non-terrestrial network communication. Satellite communication includes: low Earth orbit (LEO) satellite communication, medium Earth orbit (MEO) satellite communication, and high Earth orbit (HEO) satellite communication.

[0098] For example, LEO satellite communications, with an orbital altitude of 500–2000 km, can use satellite communication radio frequency signals in frequency bands that include uplink (e.g., 1668 MHz–1675 MHz) and downlink (e.g., 1518 MHz–1525 MHz). MEO satellite communications can have an orbital altitude of 8000–20000 km. HEO satellite communications, such as Tiantong or Beidou, can have an orbital altitude of approximately 35786 km above the Earth's surface. The communication frequency bands used can include uplink (e.g., 1980 MHz–2010 MHz) and downlink (e.g., 2170 MHz–2200 MHz), or uplink (e.g., 1610 MHz–1626 MHz) and downlink (e.g., 2483 MHz–2500 MHz). Satellite communication can support sending and receiving text messages, making and receiving phone calls, and data services such as voice calls and internet access.

[0099] Alternatively, the satellite positioning system supported by the electronic device can be a Global Navigation Satellite System (GNSS). This GNSS may include Global Positioning System (GPS), BeiDou Navigation Satellite System (BDS), etc.

[0100] The electronic devices in this application embodiment can be mobile phones, tablets, laptops, smart home devices, smart bracelets, smartwatches, smart helmets, smart glasses, automobiles, etc. Electronic devices can also be handheld devices with wireless communication capabilities, computing devices, 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. This application embodiment does not impose special limitations on the specific form of the electronic devices.

[0101] For ease of explanation, the following description uses a car as an example of the electronic device provided in the embodiments of this application. Figure 2 As shown, the electronic device 10 may include a housing 11 and multiple antenna devices 20. The housing 11 may, for example, include the body shell of a vehicle. The multiple antenna devices are disposed inside the housing for radiating antenna beams, thereby enabling communication between the electronic device (vehicle) and other terminal devices. These other terminal devices may include any of the aforementioned electronic devices.

[0102] In one possible implementation, the other terminal device is a mobile phone or watch, which has a digital car key installed. For example, the terminal device includes a digital car key application, or the digital car key functionality is integrated into the terminal device's operating system. In some examples, the car and other terminal devices constitute a digital car key system.

[0103] This application's embodiments limit the communication technology used in digital car keys. Depending on the communication technology used, digital car keys may include: Bluetooth digital car keys, near field communication (NFC) digital car keys, ultra-wideband (UWB) digital car keys, and flashing digital car keys, etc. For ease of explanation, the following description uses a Bluetooth digital car key system as an example.

[0104] Bluetooth communication technology enables short-range secure communication between cars and other terminal devices. When the car's Bluetooth is connected to other terminal devices, functions such as automatically unlocking / locking the doors, opening the trunk, locating the car, and starting the engine can be realized, enhancing the car user's experience when the car is empty.

[0105] To ensure a stable connection between the car and the digital car key in all directions, in some embodiments, the following continues... Figure 2 As shown, the multiple antenna devices 20 may include a first antenna device 201, a second antenna device 202, a third antenna device 203, a fourth antenna device 204, and a fifth antenna device 205. The second antenna device 202, the third antenna device 203, the fourth antenna device 204, and the fifth antenna device 205 are arranged around the first antenna device 201. Based on this, the first antenna device 201, the second antenna device 202, the third antenna device 203, the fourth antenna device 204, and the fifth antenna device 205 can complement each other, reducing signal obstruction or attenuation caused by other structural components in the electronic device 10, such as the housing 11.

[0106] For example, in a scenario where a car is connected to a digital car key, the first antenna device 201 located in the center can be used to receive signals from inside the car to detect whether the digital car key is inside the car. The second antenna device 202, the third antenna device 203, the fourth antenna device 204, and the fifth antenna device 205 located on the periphery can receive signals from all around the electronic device 10 (car), thereby achieving omnidirectional signal reception and transmission and ensuring the working stability of the digital car key.

[0107] In one possible implementation, the first antenna device 201 located in the center can be installed on the roof of the car. In another possible implementation, the second antenna device 202, the third antenna device 203, the fourth antenna device 204, and the fifth antenna device 205 located on the outer periphery can be installed inside the door handles of the car.

[0108] The antenna device 20 can be implemented in various ways. In some embodiments, such as Figure 3 As shown, the antenna device may include a circuit board assembly 40 and an antenna structure 30, with the circuit board assembly 40 being electrically connected to the antenna structure 30. The circuit board assembly 40 may include a circuit board 41 and a cable 42. Along a first direction (Y direction), the circuit board 41 includes a first end E1 and a second end E2, the cable 42 is connected to the first end E1 of the circuit board 41, and the antenna structure 30 is connected to the second end E2 of the circuit board 41.

[0109] The cable 42 can be implemented in various ways. For example, the cable 42 may include at least one of a signal line, a control line, an input lead, or an output lead. Connecting the cable 42 to one end of the circuit board 41, such as connecting the cable 42 to the first end E1 of the circuit board 41, facilitates debugging or testing of the interface.

[0110] The circuit board 41 can be implemented in various ways. This application does not limit the shape of the circuit board 41; it can be circular, polygonal, or irregular in shape. When the circuit board 41 is circular or irregular in shape, the end where the circuit board 41 is connected to the cable 42 can be considered as the first end E1 of the circuit board 41, and the end where the antenna structure 30 is located on the circuit board 41 can be considered as the second end E2 of the circuit board 41.

[0111] In some embodiments, circuit board 41 may include a dielectric layer, a ground layer, and a metal pattern layer, the metal pattern layer and the ground layer being electrically connected through vias. The dielectric layer may be a flame-retardant material (FR-4) dielectric board, a Rogers dielectric board, or a hybrid dielectric board of Rogers and FR-4, etc. Here, FR-4 is a designation for a flame-retardant material grade, and a Rogers dielectric board is a high-frequency board.

[0112] A grounding layer may comprise a continuous metal layer, which may be referred to as a ground plane or grounding plate. The grounding layer can be used for grounding electronic components. Any of the aforementioned grounding layers, grounding plates, or grounding metal layers are made of a conductive material. In some embodiments, the conductive material may be any of the following: copper, aluminum, stainless steel, brass and alloys thereof, copper foil on an insulating substrate, aluminum foil on an insulating substrate, gold foil on an insulating substrate, silver-plated copper, silver-plated copper foil on an insulating substrate, silver foil on an insulating substrate and tin-plated copper, graphite-impregnated cloth, graphite-coated substrates, copper-plated substrates, brass-plated substrates, and aluminum-plated substrates. Furthermore, the grounding layer / grounding plate / grounding metal layer may also be made of other conductive materials.

[0113] The metal pattern layer may include metal traces and metal blocks (e.g., copper drain areas). Metal blocks are used for grounding electronic components, and metal traces can be coupled to the electronic components carried on the circuit board 41, enabling signal transmission between different electronic components via the metal traces. In addition to the ground plane or metal blocks of the metal pattern layer on the circuit board, electronic devices may also have other ground planes / grounding planes. The metal pattern layer can be formed by patterning a metal layer carried by a dielectric layer using processes (including metal etching, printing, inkjet printing, etc.).

[0114] In some embodiments, the circuit board 41 may include multiple dielectric layers, multiple ground layers, and multiple metal pattern layers. A metal pattern layer or a ground layer may be located between two adjacent dielectric layers. Different metal pattern layers may be connected through vias that penetrate the dielectric layers.

[0115] For ease of explanation, Figure 3 An XYZ coordinate system is established, with the direction from the first end E1 to the second end E2 defined as the Y direction, the thickness direction of the circuit board 41 defined as the Z direction, and the X direction perpendicular to both the Y and Z directions. The Y direction is also referred to as the first direction Y. The coordinate system definitions in subsequent figures are similar and will not be repeated.

[0116] right Figure 3 The radiation pattern of the antenna device 20 shown in the figure was simulated, and the simulation results are as follows: Figures 4 to 6 As shown. Among them, Figure 4 yes Figure 3 Simulation results for the case where only antenna structure 30 is operational. Figure 5 These are simulation results under the condition that antenna structure 30 and cable 42 operate simultaneously, as shown in Figure 3. Figure 6 Curve ① in the middle is Figure 4 The cross-section of the orientation pattern in the horizontal plane (YZ plane). Figure 6 Curve ② in the middle is Figure 5 The direction pattern in the image is a cross-section on the horizontal plane (YZ plane). Figure 6In the left half of the coordinate system, Phi = 90°, Theta ∈ [0°, 180°]. Figure 6 The coordinate system of the right half of the middle side is Phi = 270°, Theta ∈ [0°, 180°]. The subsequent screenshots of the antenna patterns on the YZ plane are similar and will not be repeated.

[0117] contrast Figure 4 and Figure 5 It can be seen that when the antenna structure 30 works alone, the radiation pattern of the antenna device 20 is uniform; when the antenna structure 30 and the cable 42 work simultaneously, the radiation pattern of the antenna device 20 is split.

[0118] contrast Figure 6 From curves ① and ②, it can be seen that the gain of the radiation pattern corresponding to curve ① is basically equal in all directions, and the non-circularity R of the radiation pattern corresponding to curve ① is approximately 0. The radiation pattern corresponding to curve ② has multiple zero points, such as point ①. The point of maximum gain for the radiation pattern corresponding to curve ② is point 1, with Phi = 270°, Theta = 112°, and a gain of 7.45 dBi. The point of minimum gain for the radiation pattern corresponding to curve ② is point 2, with Phi = 90°, Theta = 52°, and a gain of -23.52 dBi. The non-circularity R of the radiation pattern corresponding to curve ② is R = 7.45 dBi - (-23.52 dBi) = 30.97 dB.

[0119] In summary, when antenna structure 30 and cable 42 are working simultaneously, the radiation pattern of antenna device 20 will produce radiation pattern lobes, and the radiation pattern in the horizontal plane (YZ plane) will also have multiple radiation pattern nulls and radiation pattern non-circularity R > 30dB.

[0120] Antenna radiation pattern, also known as antenna pattern, radiation pattern, or gain pattern, is a graphical representation of the relative field strength (normalized modulus) of the antenna's radiated field at a certain distance from the antenna, showing how the direction changes. It is typically represented by two mutually perpendicular planar radiation patterns passing through the antenna's maximum radiation direction. Antenna patterns usually have multiple radiating beams. The beam with the highest radiation intensity is called the main lobe, and the remaining beams are called side lobes. Among the side lobes, the one in the opposite direction to the main lobe is also called the back lobe. Figure 4 In this diagram, XYZ represents the radiation pattern coordinates in a Cartesian coordinate system, while Theta and Phi represent the radiation pattern coordinates in a spherical coordinate system. Theta typically ranges from 0° to 180°, and Phi typically ranges from 0° to 360°. On the color axis, dBi is the unit of power gain, with an omnidirectional antenna as the reference.

[0121] Gain is used to characterize the degree to which an antenna concentrates and radiates input power. Generally, the narrower the main lobe and the smaller the side lobes of an antenna pattern, the higher the antenna gain. In addition, the color distribution on the antenna pattern, relative to a color axis, can also be used to represent gain.

[0122] To more easily measure the improvement effect of pattern nulls, pattern non-circularity can be used as a metric. Pattern non-circularity measures the breadth of pattern coverage. For an omnidirectional antenna, pattern non-circularity refers to the gain difference between the maximum and minimum gain directions on a near-circular pattern plane. Depending on the specific application scenario, different embodiments may require pattern non-circularity to be less than 1dB, 2dB, 3dB, 4dB, 5dB, 6dB, 7dB, 8dB, 9dB, or 10dB. In this embodiment, the letter R is used to represent pattern non-circularity, and R≤10dB is used as the optimization metric for pattern non-circularity.

[0123] dB, or decibel, is a logarithmic concept with base 10. Decibels are used to evaluate the proportional relationship between two physical quantities; they themselves have no physical dimensions. For every tenfold increase in the ratio between two quantities, their difference can be expressed as 10 decibels. For example, if A = 100, B = 10, C = 5, and D = 1, then A / D = 20 dB; B / D = 10 dB; C / D = 7 dB; and B / C = 3 dB. In other words, a 10-decibel difference between two quantities is a tenfold difference, a 20-decibel difference is a 100-fold difference, and so on. A 3-decibel difference is a twofold difference between the two quantities.

[0124] for Figure 5 As shown in the radiation pattern, due to the presence of null points, when the direction of the incoming wireless communication signal corresponds to a null point, the antenna's radiation capability is weak in that direction. This can lead to a high bit error rate or even complete failure in signal reception. For example, in a digital car key system using BLE RSSI ranging, signal instability may cause the system to fail to unlock or de-lock properly, resulting in a poor user experience.

[0125] Similarly, when signal transmission is required at the angle corresponding to the null point of the radiation pattern or at other angles near that angle, the signal may fail to be transmitted normally. Therefore, the null point of the radiation pattern has a serious impact on the wireless communication of electronic devices.

[0126] To find the reason for the existence of the zero point in the directional pattern, such as Figure 7 , Figure 8 and Figure 9A As shown, for Figure 3 The current amplitude of the antenna device 20 shown is simulated. In the current amplitude simulation diagram of this embodiment, as shown... Figure 7 , Figure 8 or Figure 9A As shown, the darker the color area on circuit board 41, the smaller the current amplitude, and the lighter the color area, the larger the current amplitude. The current amplitude will not be elaborated further in the subsequent simulation diagrams.

[0127] like Figure 7 As shown, is Figure 3 The simulation results show the current amplitude when only the antenna structure 30 is working in the antenna device 20. The antenna structure 30 is excited by the feed to generate current, which can form an induced current on the circuit board 41. Parallel to the first direction Y, this induced current gradually increases.

[0128] like Figure 8 As shown, is Figure 3 The simulation results of the current amplitude in the antenna device 20 when the antenna structure 30 and the cable 42 are working simultaneously show that under the action of the induced current, there is electromagnetic coupling between the circuit board 41 and the cable 42, and the current amplitude of the circuit board 41 near the cable 42 increases significantly.

[0129] like Figure 9A As shown, is Figure 3 In the antenna device 20, when the antenna structure 30 and cable 42 are working simultaneously, another simulation result of current amplitude is obtained. The current amplitude at point ① is 10.45dB (A / m), and the current amplitude at point ② is 14.14dB (A / m). The amplitude of this induced current is relatively strong.

[0130] like Figure 9B As shown, for Figure 3 The current direction of the antenna device 20 is simulated. Figure 9B The solid arrows indicate the current direction on the surface of antenna structure 30, while the dashed arrows indicate the current direction on the surfaces of circuit board 41 and cable 42. The current direction will not be further elaborated in subsequent simulation diagrams. It can be seen that induced currents parallel to the first direction Y are generated on circuit board 41 and cable 42.

[0131] The induced current described above has several effects on the radiation pattern of the antenna device 30. In some examples, the electromagnetic coupling interferes with the existing electrical signal between the circuit board 41 and the cable 42, potentially distorting the original electrical signal and causing a directional null point in the radiation pattern of the antenna structure 30. In some examples, the induced current can generate an electromagnetic field on the motherboard, forming a surface wave. The cable is connected to the first end of the antenna structure, and the component of the surface wave along the first direction can be transmitted to the first end and continue to propagate along the cable, causing electromagnetic coupling between the circuit board and the cable. During operation, the cable 42, such as signal lines, control lines, input leads, or output leads, can receive or transmit electromagnetic waves like an antenna due to its physical length and electrical characteristics. Therefore, the original electrical signal transmitted between the cable 42 and the circuit board will be interfered with by the aforementioned surface wave.

[0132] Based on this, in order to improve the problems of antenna pattern lobes and the presence of nulls in the horizontal plane pattern, such as Figure 10 As shown, the circuit board assembly 40 may further include a choke device 43, which is electrically connected between the circuit board 41 and the cable 42. The choke device 43 can suppress the influence of the induced current generated by the antenna structure 30 on the circuit board 41 on the cable 42, thereby improving the interference between the induced current and the original electrical signal between the circuit board 41 and the cable 42, improving the problem of the original electrical signal distortion, and thus improving the problem of null points in the radiation pattern of the antenna device 20.

[0133] There are several possible implementations of the choke device 43. The choke device 43 may include an inductor, a capacitor, or a combination of both. In one possible implementation, the choke device 43 includes a combination circuit consisting of a capacitor and an inductor connected in series. In another possible implementation, the choke device 43 includes a capacitor. In yet another possible implementation, the choke device 43 includes an inductor, which may also be referred to as a radio frequency (RF) choke inductor. This inductor may be connected in series between the cable 42 and the circuit board 41.

[0134] Taking the choke device 43 including an inductor as an example, the cable is 0.5 mm away from the circuit board, and the inductor is connected in series at the solder joint between the cable and the circuit board. This application does not limit the inductance value; the inductance value is related to the specific size parameters and operating frequency band of the antenna device. For example, the inductance value can be 33 nH.

[0135] In some embodiments, electrostatic discharge (ESD) protection requires a transient voltage suppressor (TVS) diode connected in parallel at the cable solder joints due to the series inductance of the cable. Since the supply voltage is 12V, a TVS diode with a large junction capacitance is needed to prevent voltage surges. The junction capacitance of a TVS diode reaches 33pF, which is shoot-through for RF signals, causing the inductor to lose its function. In this case, although the series inductor can improve the zero-point problem in the radiation pattern to some extent, the parallel connection of the TCS diode also causes the series inductor to lose its choking effect.

[0136] Based on this, the radiation pattern of the antenna device was simulated at f = 2.44 GHz. The cross-section of the antenna radiation pattern on the horizontal plane (YZ plane) is as follows. Figure 11 As shown. Figure 11 Curve ① in the diagram is the radiation pattern of the antenna device with a 33nH inductor connected in series. Figure 11 Curve ② in the diagram is the radiation pattern of the antenna device under the condition of a series 33nH inductor and an ideally open-circuited cable. Figure 11 Curve ③ in the diagram represents the radiation pattern of the antenna device when a 33nH inductor is connected in series and the cable is ideally directly connected. Curves ① and ② essentially overlap. In all three cases described above, null points still exist in the radiation pattern of the antenna device. For example, Figure 11 Points 1 and 2 are considered. At point 1, Phi = 90°, Theta = 20°, and the gain is -6.04 dBi. At point 2, Phi = 90°, Theta = 20°, and the gain is -12.59 dBi. The gain at point 1 is greater than that at point 2. With a 33nH inductor in series, an ideal open-circuit cable provides a more significant improvement to the antenna's null point than an ideal straight-connected cable.

[0137] From the perspective of the non-circularity of the direction pattern, continue as follows: Figure 11 As shown, taking curve ③ as an example, the minimum gain point of the radiation pattern corresponding to curve ③ is point 3, with Phi = 270°, Theta = 90°, and a gain of -21 dBi. The maximum gain point of the radiation pattern corresponding to curve ③ is point 4, with Phi = 270°, Theta = 110°, and a gain of 8 dBi. The non-circularity of the radiation pattern of curve ③ is R = 8 dBi - (-21 dBi) = 29 dBi. In other words, the problems of lobes in the radiation pattern and null points in the horizontal plane of this antenna device have been improved, but they still exist.

[0138] To further improve the null point problem of the antenna pattern, in some embodiments, such as Figure 12As shown, the circuit board 41 includes a first cutout area 411, the vertical projection of the cable 42 on the circuit board 41 at least partially overlapping the first cutout area 411. In this case, the probability of electromagnetic coupling between the cable 42 and the circuit board 41 can be reduced, thereby improving the interference between the induced current and the original electrical signal between the circuit board 41 and the cable 42, improving the problem of distortion of the original electrical signal, and thus improving the problem of null points on the radiation pattern of the antenna device. In some embodiments, the first cutout area 411 can be achieved by removing the metal of the projection area of ​​the cable 42 on the circuit board 41, for example, by setting the material of the projection area as an insulating material, such as FR4.

[0139] Based on this, the radiation pattern of the antenna device was simulated at f = 2.44 GHz. The cross-section of the antenna radiation pattern on the horizontal plane (YZ plane) is as follows. Figure 13 As shown. Figure 13 Curve ① in the diagram represents the radiation pattern of the antenna device with a 33nH inductor connected in series and a first cutout area. Figure 13 Curve ② in the diagram represents the radiation pattern of the antenna device with a series 33nH inductor, a first cutout area, and an ideally open-circuited cable. Figure 13 Curve ③ in Figure 9 represents the radiation pattern of the antenna device when a 33nH inductor is connected in series, a first cutout area is provided, and the cable is ideally directly connected. In all three cases described above, null points still exist on the antenna device's radiation pattern, such as points 1, 2, and 3 in Figure 9. Specifically, at point 1, Theta = 52 degrees and the gain is -22.24 dBi; at point 2, Theta = 52 degrees and the gain is -12.519 dBi; and at point 3, Theta = 52 degrees and the gain is -9.30 dBi. The gain at point 1 is greater than that at points 2 and 3.

[0140] From the perspective of the non-circularity of the direction pattern, continue as follows: Figure 13 As shown, taking curve ③ as an example, the minimum gain point of the radiation pattern corresponding to curve ③ is at point 4, with Phi = 270°, Theta = 90°, and a gain of -20dBi. The maximum gain point of the radiation pattern corresponding to curve ③ is at point 5, with Phi = 270°, Theta = 110°, and a gain of 8dBi. The non-circularity of the radiation pattern of curve ③ is R = 8dBi - (-20dBi) = 28dBi. In other words, the problems of lobes in the 20-axis radiation pattern and null points in the horizontal plane radiation pattern of this antenna device have been improved, but they still exist.

[0141] To mitigate the traveling wave current generated on the circuit board and cables by the antenna structure, in some embodiments, such as Figure 14As shown, the circuit board 41 includes a third cutout area 413, the electrical length of which is λ / 4. The antenna structure 30 has a feed terminal P, and the electrical length of the distance D between the third cutout area 413 and the feed terminal P is less than λ / 4. Here, λ is the operating wavelength of the antenna structure. In this case, the wavelength corresponding to the frequency of the induced current is also λ. Therefore, the third cutout area 413 can suppress the induced current, thereby improving the interference between the induced current and the original electrical signal between the circuit board 41 and the cable 42, improving the problem of original electrical signal distortion, and further improving the problem of null points in the radiation pattern of the antenna device 20.

[0142] In the embodiments of this application, "end" or "one end" can be understood as either a point or a segment of the radiator including that point, such as a segment of the radiator within one-sixteenth of the operating wavelength range from that end point. In some examples, the radiator has a certain thickness, and the feed end can be disposed on the side wall of the radiator. The feed end can be understood as a segment of the side wall of the radiator including that point. For ease of labeling, the "feed end" is represented by a circular dot in the accompanying drawings of the embodiments of this application, and will not be described again in subsequent drawings.

[0143] Electrical length can be expressed as the ratio of physical length (i.e., mechanical length or geometric length) multiplied by the transmission time of an electrical or electromagnetic signal in a medium, to the time required for that signal to travel a distance in free space equal to the physical length of the medium. Electrical length can be expressed by the following formula:

[0144]

[0145] Where L is the physical length, a is the transmission time of the electrical or electromagnetic signal in the medium, and b is the transmission time in free space.

[0146] Alternatively, electrical length can also refer to the ratio of physical length (i.e., mechanical length or geometric length) to the wavelength of the transmitted electromagnetic wave, and electrical length can satisfy the following formula:

[0147]

[0148] Where L is the physical length and λ is the wavelength of the electromagnetic wave.

[0149] In some embodiments of this application, the physical length of the radiator can be understood as within ±20%, ±10%, or ±5% of the electrical length of the radiator.

[0150] right Figure 14 The current amplitude of the antenna device was simulated, and the simulation results are shown in Figure 15. The current amplitude at point ① is 2.17 dB (A / m), and the current amplitude at point ② is 9.27 dB (A / m). (Comparison) Figure 15A and Figure 9A The current amplitude at points ① and ② both decreased, and the third cutout area 413 has a suppressive effect on the induced current on the circuit board.

[0151] right Figure 14 The radiation pattern of the antenna device is simulated, and the cross-section of the antenna radiation pattern on the horizontal plane (YZ plane) is shown below. Figure 15B As shown in curve ①. For comparison, Figure 14 The radiation pattern of the central antenna device, excluding the third hollowed-out region 413, is plotted in a cross-section on the horizontal plane (YZ plane) in the same coordinate system, such as... Figure 15B As shown in curve ② in the figure. Figure 15B At point 1, Phi = 90°, Theta = 34°, and the gain shift is -6.73 dBi; at point 2, Phi = 90°, Theta = 34°, and the gain shift is -15.12 dBi; at point 3, Phi = 270°, Theta = 68°, and the gain shift is -3.5 dBi.

[0152] From the perspective of the non-circularity of the direction pattern, continue as follows: Figure 15B As shown, the minimum gain point of the radiation pattern corresponding to curve ① is point 4, with Phi = 270°, Theta = 90°, and a gain of -16 dBi. The maximum gain point of the radiation pattern corresponding to curve ① is point 5, with Phi = 270°, Theta = 112°, and a gain of 3.5 dBi. The non-circularity of the radiation pattern of curve ① is R = 3.5 dBi - (-16 dBi) = -19.5 dBi. The minimum gain point of the radiation pattern corresponding to curve ① is point 6, with Phi = 90°, Theta = 58°, and a gain of -24 dBi. The maximum gain point of the radiation pattern corresponding to curve ② is point 7, with Phi = 270°, Theta = 112°, and a gain of 7 dBi. The non-circularity of the radiation pattern of curve ② is R = 7 dBi - (-24 dBi) = -31 dBi. In other words, the problem of the null point of the horizontal plane radiation pattern of the antenna device 20 including the third hollow area 413 (curve ①) is improved compared to that without the third hollow area 413 (curve ②), but it still exists.

[0153] In the above example, for example Figure 14 In this configuration, the vertical projection of the antenna structure 30 onto the XY plane does not overlap with the vertical projection of the circuit board 41 onto the XY plane. In some embodiments, such as... Figure 16 As shown, the vertical projection of the antenna structure 30 onto the XY plane overlaps with the vertical projection of the circuit board 41 onto the XY plane. For example, the antenna structure 30 is disposed on a metal pattern layer of the circuit board 41.

[0154] right Figure 16 The current amplitude of the antenna device 20 is simulated, such as... Figure 17As shown, the current amplitude is stronger near the center of the antenna structure 30, and weaker near the first end E1 and the second end E2. The induced current amplitude on the circuit board 41 is stronger near the center of the antenna structure 30, and weaker near the first end E1 and the second end E2. The current amplitude at point ① is 5.91 dB(A / m).

[0155] The terms "midpoint," "middle," or "middle position," etc., used in the embodiments of this application refer to specific ranges or distances. For example, the midpoint, middle, or middle position of a conductor can be a section of the conductor including its geometric midpoint, or a section of the conductor including its geometric midpoint that is one-eighth of the operating wavelength. As another example, the midpoint, middle, or middle position of a conductor can be a section of the conductor located less than a predetermined threshold (e.g., 1 mm, 2 mm, or 2.5 mm) from its geometric midpoint. The geometric midpoint position of a slot or the geometric midpoint position of one side of a slot refers to the geometric midpoint position of one side of the slot.

[0156] right Figure 16 The current direction of the antenna device 20 is simulated, such as... Figure 18 As shown, an induced current parallel to the first direction Y is generated on the circuit board 41 and the cable 42.

[0157] right Figure 16 The radiation pattern of the antenna device 20 is simulated, and the cross-section of the antenna radiation pattern on the horizontal plane (YZ plane) is as follows. Figure 19 As shown. From the perspective of pattern non-circularity, the minimum gain point of this pattern is point 1, with a gain of -26 dBi. The maximum gain point of this pattern is point 2, with a gain of 0 dBi. The pattern non-circularity of curve ③ is R = 0 dBi - (-26 dBi) = 26 dB.

[0158] In order to improve Figure 16 The traveling wave current generated on the circuit board and cables by the antenna structure, in some embodiments, such as Figure 20 As shown, the circuit board 41 includes a second cutout area 412, the vertical projection of the antenna structure 30 on the circuit board 41 of which at least partially overlaps with the second cutout area 412. In this case, the second cutout area 412 can reduce the probability of the antenna structure 30 generating an induced current on the circuit board 41, thereby improving the interference between the induced current and the original electrical signal between the circuit board 41 and the cable 42, improving the problem of the original electrical signal distortion, and thus improving the problem of the null point of the radiation pattern of the antenna device 20.

[0159] There are several possible implementations for the second hollow area 412. In one possible implementation, such as... Figure 21As shown, the second cutout area 412 is located at the middle position of the circuit board 41 along the X direction. In one possible implementation, as... Figure 20 As shown, the second cutout area 412 is located on one side of the circuit board 41 along the X direction.

[0160] right Figure 20 The current amplitude of the antenna device 20 is simulated, such as... Figure 22 As shown, the current amplitude at point ① is 12.22 dB (A / m). (Comparison) Figure 22 and Figure 17 The current amplitude at point ① increases, the current amplitude at point ② decreases, and the current amplitude at a local location on the cable decreases.

[0161] right Figure 20 The current amplitude of the antenna device 20 is simulated, such as... Figure 23 As shown, there is still an induced current parallel to the first direction Y on the circuit board 41 and the cable 42.

[0162] right Figure 20 The radiation pattern of the antenna device 20 is simulated, and the cross-section of the antenna radiation pattern on the horizontal plane (YZ plane) is as follows. Figure 24 As shown. From the perspective of pattern non-circularity, the minimum gain point of this pattern is at point 1, with a gain of -17 dBi. The maximum gain point of this pattern is at point 2, with a gain of 2 dBi. The pattern non-circularity is R = 2 dBi - (-17 dBi) = 19 dB. Compared to... Figure 16 With R=26dB, the non-circularity of the radiation pattern is improved, meaning the antenna direction and null point are improved.

[0163] In summary, Figure 20 The antenna device 20 shown still has the problem of null points in the horizontal plane radiation pattern, but Figure 20 Antenna device 20 in the middle relative to Figure 19 The antenna device 20 in the middle has improved the zero point of the horizontal plane radiation pattern.

[0164] The above description assumes that the antenna device also includes a second cutout area, assuming the vertical projection of the antenna structure onto the XY plane overlaps with the vertical projection of the circuit board onto the XY plane. In one possible implementation, such as... Figure 25 , Figure 26 or Figure 27 As shown, the antenna device may also include a third hollowed-out area. In one possible implementation, such as Figure 25 As shown, circuit board 41 includes multiple third cutout areas 413. For example, circuit board 14 includes two third cutout areas 413, which are located on opposite sides of circuit board 41 along the X direction. In one possible implementation, such as... Figure 26As shown, the vertical projection of the antenna structure 30 onto the circuit board 41 at least partially overlaps with the third cutout area 413. In one possible implementation, such as Figure 27 As shown, the circuit board 41 includes a second cutout area 412 and a third cutout area 413.

[0165] right Figure 25 The current distribution of the antenna device 20 is simulated, such as... Figure 28 As shown, the current amplitude at point ① is 10.8 dB (A / m). For Figure 26 The current distribution of the antenna device 20 is simulated, such as... Figure 29 As shown, the current amplitude at point ② is 14.3 dB (A / m). For Figure 27 The current distribution of the antenna device 20 is simulated, such as... Figure 30 As shown, the current amplitude at point ③ is 10.2 dB (A / m). Comparing the current amplitudes at points ①, ②, and ③, it can be concluded that... Figure 21 The middle circuit board 41, including the second cutout area 412 and the third cutout area 413, has a good suppression effect on induced current.

[0166] right Figure 25 , Figure 26 and Figure 27 The radiation pattern of the antenna device 20 is simulated, such as... Figure 31 As shown. Figure 31 Curve ① in the text is Figure 25 The radiation pattern of the antenna device shows that the minimum gain point of the radiation pattern corresponding to curve ① is point 1, with a gain of -17 dBi. The maximum gain point of the radiation pattern corresponding to curve ① is point 4, with a gain of 2 dBi. The non-circularity of this radiation pattern is R = 2 dBi - (-17 dBi) = 19 dB. Figure 31 Curve ② in the text is Figure 26 The radiation pattern of the antenna device is shown. The minimum gain point of the radiation pattern corresponding to curve ② is point 2, with a gain of -6 dBi. The maximum gain point of the radiation pattern corresponding to curve ② is point 4, with a gain of 2 dBi. The non-circularity of this radiation pattern is R = 2 dBi - (-6 dBi) = 8 dB. Figure 31 Curve ③ in the middle is Figure 27 The radiation pattern of the antenna device shows that the minimum gain point of curve ③ is at point 3, with a gain of -12 dBi. The maximum gain point of curve ② is at point 5, with a gain of 0 dBi. The non-circularity of this radiation pattern is R = 0 dBi - (-12 dBi) = 12 dB. In all three cases, the null point in the radiation pattern of antenna device 20 still exists, but it is improved.

[0167] The above description illustrates how improvements to the circuit board assembly can improve the null point problem of the antenna device. In some embodiments, improvements to the antenna structure can also improve the null point problem of the antenna device.

[0168] Antenna structures commonly used in electronic devices include inverted-L antennas (ILA) and inverted-F antennas (IFA), which are common-mode antennas. Figure 3 The antenna structure 30 shown is an ILA. In some embodiments, such as Figure 32 As shown, the antenna structure 30 adopts a different approach. Figure 3 Other common-mode antennas in the ILA.

[0169] right Figure 32 The current amplitude of the antenna device 20 is simulated, such as... Figure 33 As shown, the current amplitude at point ① is 10.3 dB (A / m), indicating a relatively high induced current amplitude on the circuit board. The current amplitude at point ② is 13.9 dB (A / m), indicating a relatively high induced current amplitude on the cable.

[0170] right Figure 32 The current direction of the antenna device 20 is simulated, such as... Figure 34 As shown, the antenna structure has a first current I1 and a second current I2 parallel to the first direction Y. The first current I1 and the second current I2 induce an induced current I3 parallel to the first direction Y on the circuit board. The induced current I3 propagates to the cable in the opposite direction of the first direction Y.

[0171] In combination with the above Figure 3 , Figure 16 Figure 32 Analysis of the antenna device 20 shows that the induced current parallel to the first direction Y is generated on the circuit board 41 and the cable 42 because the current on the antenna structure 30 has a component parallel to the first direction Y, and the induced current on the circuit board 41 cancels each other out or forms a current loop, which then propagates to the cable 42.

[0172] Therefore, embodiments of this application also provide an antenna device, such as... Figure 35As shown, the antenna device 20 may include a circuit board 41, a cable 42, and an antenna structure 30. Along the first direction Y, the circuit board 41 includes a first end E1 and a second end E2. The cable 42 is connected to the first end E1 of the circuit board 41, and the antenna structure 30 is connected to the second end E2 of the circuit board 41. The antenna structure 30 includes a first radiator 31 and a second radiator 32. The first radiator 31 has a first feed end P1 for receiving a first feed signal. The second radiator 32 has a second feed end P2 for receiving a second feed signal. At least one of the first and second feed signals is used to adjust the non-circularity R of the antenna structure 30's radiation pattern, where R ≤ 10 dB.

[0173] Specifically, the closer the non-circularity R of the radiation pattern is to 0, the smaller the difference between the maximum and minimum gain on the radiation pattern, resulting in fewer nulls in the antenna structure's radiation pattern and improving the null problem of the antenna device. The following will explain this with specific radiation patterns in mind.

[0174] The antenna structure 30 can be implemented in various ways. In some embodiments, such as Figure 35 As shown, the physical length d1 of the first radiator 31 and the physical length d2 of the second radiator 32 are equal, or the electrical length of the first radiator 31 and the electrical length of the second radiator 32 are equal.

[0175] The first radiator 31 includes a first electrical connection terminal 01 and a second electrical connection terminal 02, with the first power supply terminal P1 disposed at the second electrical connection terminal 02.

[0176] The second radiator 32 includes a third electrical connection terminal 03 and a fourth electrical connection terminal 04, with a second power supply terminal P2 disposed at the third electrical connection terminal 03. The second electrical connection terminal 02 is closer to the third electrical connection terminal 03 than the first electrical connection terminal 01. The third electrical connection terminal 03 is closer to the second electrical connection terminal 02 than the fourth electrical connection terminal 04.

[0177] In this case, the current amplitude on the first radiator 31 decreases along the direction from the second electrical connection terminal 02 to the first electrical connection terminal 01. Similarly, the current amplitude on the second radiator 32 decreases along the direction from the third electrical connection terminal 03 to the fourth electrical connection terminal 04. The similarity between the current distribution on the first radiator 31 and the current distribution on the second radiator 32 helps the antenna structure 30 form a more symmetrical radiation pattern, thereby enabling electronic devices using this antenna device 20 to provide more uniform signal coverage.

[0178] Based on this, in one possible implementation, such as Figure 36As shown in (A), there is a first interval G1 between the second electrical connection terminal 02 and the third electrical connection terminal 03. This is a relatively simple implementation of the antenna structure 30.

[0179] In one possible implementation, such as Figure 36 As shown in (B), the second electrical connection terminal 02 is connected to the third electrical connection terminal 03. In this case, the portion of the conductor between the first feed terminal P1 and the second feed terminal P2 can be considered as a load. The physical length of this portion of the conductor can determine the load value, and a suitable load value can enable the antenna structure 30 to achieve good impedance matching.

[0180] In one possible implementation, such as Figure 36 As shown in (A), the first electrical connection terminal 01 is left floating, and the fourth electrical connection terminal 04 is left floating. This is a relatively simple practical method for antenna structure. Here, "floating" means not connected to any external device.

[0181] In one possible implementation, such as Figure 36 As shown in (C), the first electrical connection terminal 01 is connected to the fourth electrical connection terminal 04. The voltages of the first feed signal and the second feed signal are different. In this case, the first feed signal can be transmitted to the second radiator 32 through the fourth electrical connection terminal 04, and the second feed signal can be transmitted to the first radiator 31 through the first feed terminal 01. The superposition of the first and second feed signals can increase the input impedance of the antenna structure 30, thereby making it easier for the antenna structure 30 to achieve impedance matching. In some examples, the antenna structure 30 includes a folded dipole.

[0182] exist Figure 36 (B) or Figure 36 In the case shown in (C), the embodiments of this application do not limit the boundary between the first radiator 31 and the second radiator 32. In some examples, such as Figure 36 As shown in (B), the portion from the first feed terminal P1 to the first open terminal O1 can be considered as belonging to the first radiator 31, and the portion from the second feed terminal P2 to the fourth open terminal O4 belongs to the second radiator 32. The portion between the first feed terminal P1 and the second feed terminal P2 is part of both the first radiator 31 and the second radiator 32. In some examples, such as... Figure 36 As shown in (C), the perpendicular bisector of the line connecting the first feed terminal P1 and the second feed terminal P2 is a straight line L. It can be considered that the radiator on the side of the straight line L facing the first feed terminal P1 is the first radiator, and the radiator on the side of the straight line L facing the second feed terminal P2 is the second radiator.

[0183] Therefore, the implementation of the first radiator 31 and the second radiator 32 in the antenna structure can be varied. In some embodiments, such as Figure 35 As shown, the first radiator 31 and the second radiator 32 are arranged along a second direction, which intersects the first direction Y. The first radiator 31 is strip-shaped and extends along the second direction. The second radiator 32 is strip-shaped and extends along the second direction.

[0184] based on Figure 35 The antenna device shown is fed with different first feed signals and second feed signals, such as Figure 37 or Figure 40 As shown. Figure 37 or Figure 40 In the circuit, the first feed terminal P1 of the first radiator 31 receives a first feed signal and generates a first current I1 on the first radiator 31. The first current I1 induces a third current I3 on ​​the circuit board 41, and the first current I1 and the third current I3 are in opposite directions. The second feed terminal P2 of the second radiator 32 receives a second feed signal and generates a second current I2 on the second radiator 32. The second current I2 induces a fourth current I4 on the circuit board 41, and the second current I2 and the fourth current I4 are in opposite directions.

[0185] Because the first direction Y and the second direction intersect, the component of the third current I3 parallel to the first direction Y is weakened, and the component of the fourth current I4 along the first direction is weakened. Consequently, the surface waves excited by the third current I3 and the fourth current I4 are weakened. Since the surface waves excited by the induced currents (the third current I3 or the fourth current I4) are weakened, the energy that these surface waves can transmit to the cable 42 is also weakened. The electromagnetic coupling between the circuit board 41 and the cable 42 is weakened, which can improve the interference between this electromagnetic coupling and the original electrical signal between the circuit board 41 and the cable 42, improve the problem of the original electrical signal distortion, and thus improve the problem of the null point of the radiation pattern of the antenna device 20.

[0186] Components are used to synthesize vectors. A vector is a physical quantity that has both magnitude and direction. A vector can be decomposed into multiple components. When studying the direction of electric current, the current can be regarded as a vector.

[0187] This application does not limit the angle between the first direction and the second direction. The first direction and the second direction intersect, and the angle between them is not 0°, which falls within the scope of protection of this application. For ease of explanation, the following description uses an example where the angle between the first direction and the second direction is 90 degrees (i.e., the first direction and the second direction are perpendicular).

[0188] In one possible implementation, the first direction Y is perpendicular to the second direction, meaning the second direction is parallel to the X direction. In some examples, the second direction can be the X direction. In this case, the component of the surface wave parallel to the first direction Y can theoretically be zero, thus further improving the problem of null points in the radiation pattern of the antenna device 20. Furthermore, since the antenna structure 30 is located at the first end of the circuit board 41, and the first radiator 31 and the second radiator 32 are arranged along the second direction, the perpendicularity of the first direction Y and the second direction can also save space on the circuit board 41.

[0189] With the antenna structure 30 being the same, the implementation methods of the first and second feed signals may vary depending on the different voltage relationships between the first and second feed signals. In one possible implementation, such as... Figure 37 As shown, the first feed signal and the second feed signal have equal amplitudes but opposite phases. That is, the first feed signal and the second feed signal are a differential signal pair. In this case, the first current I1 and the second current I2 have equal amplitudes and the same direction. The third current I3 induced by the first current I1 and the fourth current I4 induced by the second current I2 also have similar amplitudes and the same direction. Based on this, the current amplitude of the antenna device 20 is simulated, and the simulation results are as follows... Figure 55 As shown, the current amplitude at the connection point (point A) between circuit board 41 and cable 42 is significantly reduced, and the antenna structure 30 has a significant effect on improving the induced current parallel to the first direction Y on antenna device 20.

[0190] The above explanation uses the first and second feed signals as differential signals as an example. In some examples, by adjusting the voltage relationship between the first and second feed signals, a similar effect to a differential signal can be produced. In one possible implementation, one of the first and second feed signals has a voltage of zero, while the other has a high voltage level. For example, one of the first and second feed terminals is grounded, and the other is connected to the feed source.

[0191] To achieve the differential effect, this application also provides a feeding circuit, such as... Figure 39 As shown, the first feed terminal P1 is electrically connected to the feed source and is used to receive the first feed signal. The second feed terminal P2 is electrically connected to the feed source and is used to receive the second feed signal. The feed circuit consists of multiple capacitors and multiple inductors, used to adjust the voltage relationship between the first and second feed signals. The specific values ​​of the capacitors and inductors are determined by the specific application scenario, and this application does not impose any restrictions on them. In one possible implementation, C1 = 0.2pF, C2 = 0.2pF, C3 = 0.9pF, L1 = 4.3nH, L2 = 4.7nH, L3 = 2.4nH, L4 = 4.7nH, and L5 = 2.4nH.

[0192] The above explanation uses the example of the first and second feed signals producing a differential effect. In one possible implementation, such as... Figure 40 As shown, the first and second feed signals have equal amplitudes and the same phase. That is, the first and second feed signals are a common-mode pair. In this case, the first current I1 and the second current I2 have equal amplitudes but opposite directions. The third current I3 induced by the first current I1 and the fourth current I4 induced by the second current I2 also have similar amplitudes but opposite directions; some components of the third current I3 and the fourth current I4 can cancel each other out.

[0193] To reduce the area occupied by the antenna structure 30 in the X direction and adapt to applications where space is limited in the X direction in some electronic devices, such as the application scenario of installing the antenna device 20 in the door handle of a car, in some embodiments, such as Figure 41 As shown, the first radiator 31 includes a first branch 301, which extends parallel to the first direction Y. The second radiator 32 includes a second branch 302, which also extends parallel to the first direction Y. The voltages of the first feed signal and the second feed signal are different.

[0194] Based on this, the first feed terminal P1 and the second feed terminal P2 can be implemented in various ways. In one possible implementation, the end of the first radiator facing the cable is the first feed terminal P1, and the end of the second radiator facing the cable is the second feed terminal P2.

[0195] To facilitate the connection of the first radiator 31 and the second radiator 32 to the feed source, in one possible embodiment, the first radiator 31 further includes a third branch 303 extending along a second direction. The end of the first branch 301 opposite to the third branch 303 is a first electrical connection terminal 01, and the end of the third branch 303 opposite to the first branch 301 is a second electrical connection terminal 02. The second radiator 32 further includes a fourth branch 304 extending along the second direction. The end of the second branch 302 opposite to the fourth branch 304 is a fourth electrical connection terminal 04, and the end of the fourth branch 304 opposite to the second branch 302 is a third electrical connection terminal 03. In this case, there is a second gap G2 between the first electrical connection terminal 01 and the fourth electrical connection terminal 04. In some examples, the third branch 303 and the fourth branch 304 are connected, that is, the third electrical connection terminal 03 is connected to the fourth electrical connection terminal 04. The effect of connecting the third electrical connection terminal 03 and the fourth electrical connection terminal 04 is the same as described above.

[0196] right Figure 41 Simulation of the current distribution of the antenna device, such as... Figure 42As shown. The first branch generates current I11, which induces current I31 on the circuit board. The third branch generates current I12, which induces current I32 on the circuit board. The second branch generates current I21, which induces current I41 on the circuit board. The fourth branch generates current I22, which induces current I42 on the circuit board. Because the first direction Y intersects with the second direction, the components of currents I42 and I32 in the first direction Y are smaller. Currents I31 and I41 have similar amplitudes but opposite directions, so at least part of currents I31 and I41 can cancel each other out. In summary, the current propagating parallel to the first direction Y is reduced. In some examples, currents I41, I42, I32, and I31 are connected end-to-end to form a current loop, further reducing the current propagating parallel to the first direction Y. The reduction in current propagating parallel to the first direction Y weakens the electromagnetic coupling between the circuit board and the cable, which can improve the interference between the electromagnetic coupling and the original electrical signal between the circuit board and the cable, improve the problem of the original electrical signal distortion, and thus improve the problem of the null point of the radiation pattern of the antenna device 20.

[0197] To adjust the impedance matching of the antenna structure, in some embodiments, such as Figure 43 As shown, antenna structure 30 includes a fifth stub 305, a sixth stub 306, and a seventh stub 307. The fifth stub 305 extends parallel to the first direction Y, and the sixth stub 306 also extends parallel to the first direction Y. One end of the fifth stub 305 is connected to the second electrical connection terminal 02, one end of the sixth stub 306 is connected to the third electrical connection terminal 03, one end of the seventh stub 307 is connected to the other end of the fifth stub 305, and the other end of the seventh stub 307 is connected to the other end of the sixth stub 306. In this configuration, the second electrical connection terminal 02 and the third electrical connection terminal 03 are connected via the fifth stub 305, the sixth stub 306, and the seventh stub 307. To achieve better radiation performance of antenna structure 30, in some examples, [further details are needed]. Figure 43 As shown, the circuit board also includes a second cutout area 412.

[0198] right Figure 43 The current direction of the antenna structure and circuit board in the antenna device is simulated, such as... Figure 44 As shown. For Figure 43 The current direction on the circuit board of the antenna device is simulated, such as... Figure 45 As shown. From Figure 44 or Figure 45 As can be seen, the antenna structure induces currents I31 and I41 parallel to the first direction on the circuit board. Currents I31 and I41 can at least partially cancel each other out, thereby reducing the component of the induced current parallel to the first direction and weakening the electromagnetic coupling between the circuit board and the cable.

[0199] right Figure 43 Simulation of the current amplitude in the antenna device, such as... Figure 46 As shown, the current amplitude at point ① is -7.16 dB (A / m), and the current amplitude at point ② is -0.92 dB (A / m). The current in the cable is compared to... Figure 3 The fact that the current in the cable of the antenna device is 15dB weaker also indicates that the electromagnetic coupling between the circuit board and the cable is significantly weakened.

[0200] right Figure 43 Simulate the radiation pattern of the antenna device, such as... Figure 47 and Figure 48 As shown. Figure 47 for Figure 43 The three-dimensional radiation pattern of the antenna device. Figure 48 yes Figure 47 A cross-section on the horizontal plane (YZ plane). Comparison. Figure 47 and Figure 5 The pattern of lobes in the radiation pattern has been significantly improved. (Comparison) Figure 48 and Figure 6 The problem of zero points in the radiation pattern on the horizontal plane of curve ① has also been significantly improved.

[0201] From the perspective of the non-circularity of the direction pattern, continue as follows: Figure 48 As shown, the maximum gain of the radiation pattern corresponding to curve ① is at point 1, where Theta = 0° and the gain is -0.90 dBi. The minimum gain of the radiation pattern is at point 2, where Phi = 90°, Theta = 90° and the gain is -1 dBi. The non-circularity of the radiation pattern of curve ① is R = -0.90 dBi - (-1 dBi) = 0.1 dB ≤ 10 dB, indicating good non-circularity.

[0202] right Figure 43 Simulations were performed on other electrical parameters of the antenna device, such as... Figure 49 As shown. Figure 49 Curve ① in the figure represents the simulation result of the isolation of the antenna device. The curve has an isolation dip at point B, indicating that the isolation is less than -6dB. The frequency at point B corresponds to 2.44GHz, which means that the antenna device can operate in the Bluetooth band or the WiFi 2.4G band. Figure 49 Curve ② in the figure shows the simulation results of the radiation efficiency of the antenna device. At a frequency of 2.44 GHz, the radiation efficiency of the antenna device is about -1.6 dB, which is relatively good. Figure 49 Curve ③ in the figure represents the simulation results of the overall efficiency of the antenna device. At a frequency of 2.44 GHz, the overall efficiency of the antenna device is approximately -2.2 dB, which is relatively good.

[0203] Return loss can be understood as the ratio of the signal power reflected back to the antenna port after passing through the antenna circuit to the transmit power of the antenna port. The smaller the reflected signal, the larger the signal radiated into space through the antenna, and the higher the antenna's radiation efficiency. Conversely, the larger the reflected signal, the smaller the signal radiated into space through the antenna, and the lower the antenna's radiation efficiency. Return loss can be represented by the S11 parameter, which is typically negative. A smaller S11 parameter indicates lower antenna return loss and higher radiation efficiency; a larger S11 parameter indicates higher return loss and lower radiation efficiency. In this embodiment, the frequency range with a return loss of less than -6dB is used as the operating frequency band of the antenna structure / antenna device.

[0204] Radiative 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, refers to 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.

[0205] The above description assumes a second gap G2 between the first electrical connection terminal 01 and the fourth electrical connection terminal 04. In some embodiments, such as... Figure 50 As shown, the first electrical connection terminal 01 and the fourth electrical connection terminal 04 are connected. The first power supply terminal P1 receives the first power supply signal, and the second power supply terminal P2 receives the second power supply signal. The voltages of the first power supply signal and the second power supply signal are different.

[0206] right Figure 50 Simulation of the current direction of the antenna device, such as... Figure 51 As shown. Figure 51 This is a simulation diagram of the current direction of the antenna device. The antenna structure induces currents I31, I32, I41 and I42 parallel to the first direction on the circuit board. Currents I31 and I41 can at least partially cancel each other out, and currents I32 and I42 can at least partially cancel each other out, thereby reducing the component of the induced current parallel to the first direction and weakening the electromagnetic coupling between the circuit board and the cable.

[0207] right Figure 50 Simulation of the current amplitude of the antenna device, such as... Figure 52 As shown. Figure 52 This is a current amplitude distribution diagram of the antenna device. The current amplitude at point ① is 2.98dB (A / m), which shows that the electromagnetic coupling between the circuit board and the cable is relatively weak.

[0208] right Figure 50Simulate the radiation pattern of the antenna device, such as... Figure 53 and Figure 54 As shown. Figure 53 This is the three-dimensional radiation pattern of the antenna device. Figure 54 Curve ① in the text is Figure 53 Cross-section on the horizontal plane (YZ plane), Figure 54 Curve ② in the text is Figure 5 A cross-section on the horizontal plane (YZ plane). Comparison. Figure 53 and Figure 5 The pattern of lobes in the radiation pattern has been significantly improved. (Comparison) Figure 54 The problem of zero points in the radiation pattern on the horizontal plane of curves ① and ② has also been significantly improved.

[0209] From the perspective of the non-circularity of the direction pattern, continue as follows: Figure 54 As shown, the maximum gain of the radiation pattern corresponding to curve ① is at point 1, where Theta = 0° and the gain is -1 dBi. The minimum gain of the radiation pattern is at point 2, where Phi = 90°, Theta = 90° and the gain is -5 dBi. The non-circularity of the radiation pattern of curve ① is R = -1 dBi - (-5 dBi) = 4 dB ≤ 10 dB, indicating good non-circularity.

[0210] right Figure 50 Simulations were performed on other electrical parameters of the antenna device, such as... Figure 55 As shown. Figure 55 Curve ① in the figure represents the simulation result of the isolation of the antenna device. The curve has two isolation dips at B1 and B2, and the isolation is less than -6dB. This antenna structure can be used as a dual-band antenna. Figure 55 Curve ② in the figure represents the simulation results of the overall efficiency of the antenna device. The overall efficiency at point B1 is approximately -1dB, and the overall efficiency at point B2 is approximately -4dB, indicating a good overall efficiency.

[0211] It should be noted that the specific physical and electrical lengths of each branch of the antenna structure are related to the specific application scenario. This application embodiment does not limit the physical length of each branch in the antenna structure. For example, the operating frequency band of the antenna structure includes 2.4GHz-2.485GHz, the physical length of the first branch is 33.5mm-38.5mm; the physical length of the third branch is 33.5mm-38.5mm; the sum of the physical lengths of the second and fourth branches is 8mm-11mm, and the width of the first, second, third, and fourth branches, the first feed branch, and the second feed branch is 1.5mm.

[0212] Based on this, in one possible implementation, the antenna structure operates in the frequency band of 2.4GHz-2.485GHz, such as... Figure 56As shown, the physical lengths of the first branch 301 and the second branch 302 along the X direction can be 1.50 mm, the physical lengths of the first branch 301 and the second branch 302 along the Y direction can be 33.50 mm, the physical lengths of the third branch 303 and the fourth branch 304 along the X direction can be 5.00 mm, the physical lengths of the third branch 303 and the fourth branch 304 along the Y direction can be 1.50 mm, and the length of the circuit board along the X direction can be 49.00 mm. Figure 57 As shown, the distance between the antenna structure and the circuit board along the Z direction can be 2.82 mm, and the antenna structure is mounted on a support, for example. The thickness of the circuit board can be 1.00 mm, and the distance between the first feed terminal P1 and the second feed terminal P2 can be 1.00 mm.

[0213] In the manufacturing and processing stage, the antenna structure provided in this application embodiment can be arranged in various ways within the antenna device. This application embodiment does not limit the arrangement of the antenna structure within the antenna device. In some embodiments, such as Figure 43 As shown, the antenna structure 30 can be made of rigid material and suspended on the circuit board.

[0214] To ensure the reliability and stability of the structure, such as Figure 50 or Figure 58 As shown, the antenna device may also include a bracket 44, which is connected to the circuit board, and the antenna structure is mounted on the bracket. For example, the antenna structure can be mounted on the bracket 44 using laser engraving. This type of antenna structure can also be called a "bracket antenna".

[0215] The above explanation uses a bracket antenna as an example. In some embodiments, such as... Figure 59 As shown, the antenna structure may include a first stub 301, a second stub 302, a third stub 303, and a fourth stub 304, which may be in the form of steel sheets. The first electrical connection terminal, the second electrical connection terminal (first feed terminal P1), the third electrical connection terminal (second feed terminal P2), and the fourth electrical connection terminal are connected to the circuit board via surface mount technology (SMT) solder points 45. This type of antenna structure can also be called a "steel sheet antenna".

[0216] The above explanation uses a steel sheet antenna as an example. In some embodiments, such as... Figure 60 As shown, the antenna structure 30 can be implemented through a metal layer on a cutout circuit board, or the antenna structure can be implemented through metal traces on the circuit board. This type of antenna structure can also be called a "printed antenna".

[0217] 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.

[0218] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included 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 device, characterized by include: A circuit board, along a first direction, the circuit board includes a first end and a second end; A cable, the cable being connected to the first end; An antenna structure is connected to the second end, and the antenna structure includes a first radiator and a second radiator arranged along a second direction, the second direction intersecting the first direction; The first radiator has a first feed terminal, and the second radiator has a second feed terminal; the first feed terminal is used to receive a first feed signal; the second feed terminal is used to receive a second feed signal, and at least one of the first feed signal and the second feed signal is used to adjust the non-circularity R of the antenna structure, where R ≤ 10dB.

2. The antenna device of claim 1, wherein, The physical length of the first radiator is equal to the physical length of the second radiator; The first radiator includes a first electrical connection terminal and a second electrical connection terminal opposite to each other, and the first power supply terminal is disposed at the second electrical connection terminal; The second radiator includes a third electrical connection terminal and a fourth electrical connection terminal opposite to each other, and the second power supply terminal is disposed at the third electrical connection terminal; Wherein, relative to the first electrical connection terminal, the second electrical connection terminal is closer to the third electrical connection terminal; relative to the fourth electrical connection terminal, the third electrical connection terminal is closer to the second electrical connection terminal.

3. The antenna device according to claim 1 or 2, characterized in that, The first radiator is strip-shaped and extends along the second direction; The second radiator is strip-shaped and extends along the second direction.

4. The antenna device according to claim 1 or 2, characterized in that, The first radiator includes a first branch that extends along the first direction; The second radiator includes a second branch that extends along the first direction; The voltages of the first feed signal and the second feed signal are different.

5. The antenna device according to claim 4, characterized in that, The first radiator includes a third branch extending along the second direction; the end of the first branch opposite to the third branch is the first electrical connection terminal, and the end of the third branch opposite to the first branch is the second electrical connection terminal. The second radiator includes a fourth branch that extends along the second direction; The end of the second branch that is away from the fourth branch is the fourth electrical connection terminal, and the end of the fourth branch that is away from the second branch is the third electrical connection terminal.

6. The antenna device according to claim 5, characterized in that, The antenna structure includes a fifth stub, a sixth stub, and a seventh stub; the fifth stub extends along the first direction, and the sixth stub extends along the first direction; one end of the fifth stub is connected to the second electrical connection terminal, one end of the sixth stub is connected to the third electrical connection terminal, one end of the seventh stub is connected to the other end of the fifth stub, and the other end of the seventh stub is connected to the other end of the sixth stub.

7. The antenna device according to any of claims 2-5, characterized by The second electrical connection terminal is connected to the third electrical connection terminal.

8. The antenna device according to any of claims 2-5, characterized by There is a first gap between the second electrical connection terminal and the third electrical connection terminal.

9. The antenna device according to any of claims 2-6, characterized by The first electrical connection terminal is connected to the fourth electrical connection terminal, and the voltages of the first feed signal and the second feed signal are different.

10. The antenna device according to any one of claims 2-6, characterized in that, There is a second gap between the first electrical connection terminal and the fourth electrical connection terminal.

11. The antenna device according to any one of claims 1-10, characterized in that, The first direction and the second direction are perpendicular.

12. A circuit board assembly, characterized by Used for electrical connection with the antenna structure; The circuit board assembly includes: A circuit board, along a first direction, the circuit board includes a first end and a second end; A cable, the cable being connected to the first end of the circuit board; A choke device is electrically connected between the circuit board and the cable.

13. The circuit board assembly of claim 12, wherein, Choke devices include at least one of capacitors or inductors.

14. The circuit board assembly of claim 12 or 13, wherein, The circuit board includes a first cutout area, wherein the vertical projection of the cable on the circuit board at least partially overlaps with the first cutout area.

15. The circuit board assembly of any of claims 12-14, wherein, The circuit board includes a second cutout area, wherein the vertical projection of the antenna structure on the circuit board at least partially overlaps with the second cutout area.

16. The circuit board assembly of any of claims 12-15, wherein, The circuit board includes: a third cutout area, the electrical length of which is λ / 4; The antenna structure has a feed terminal, and the electrical length of the distance between the third hollow area and the feed terminal is less than λ / 4. Wherein, λ is the operating wavelength of the antenna structure.

17. An electronic device, comprising: It includes a housing and an antenna device according to any one of claims 1-11 or a circuit board assembly according to any one of claims 12-16, wherein the antenna device or the circuit board assembly is disposed inside the housing.

18. The electronic device of claim 17, wherein, The electronic device includes five of the antenna devices; The five antenna devices include a first antenna device, a second antenna device, a third antenna device, a fourth antenna device, and a fifth antenna device; the second antenna device, the third antenna device, the fourth antenna device, and the fifth antenna device are arranged around the first antenna device.

Images