Electronic device

Abstract

The present application provides an electronic device, which is a foldable electronic device, comprising: a first frame, at least part of the first frame forming a first branch, the first branch being a radiator of a first antenna, and the first antenna operating in at least two operating frequency bands; a second frame, at least part of the second frame forming a second branch, and when the electronic device is in a folded state, the second branch at least partially overlapping the first branch; a flexible circuit board, connected to the second branch and grounded; and a first tuning circuit, arranged on the flexible circuit board and electrically connected to the flexible circuit board, wherein the first tuning circuit comprises a plurality of first tuning links, the first tuning circuit enables the second branch to operate in at least two operating frequency bands, and the operating frequency bands of the first antenna are different from the operating frequency bands of the second branch. The present invention can resolve a conflict of a connection position of the second branch with other functional structures of the electronic device, and occupies a small space. Moreover, no separate structure for carrying the first tuning circuit is required, thereby simplifying the structure of the electronic device.

Description

electronic devices

[0001] This application claims priority to Chinese Patent Application No. 202411219813.X, filed on August 30, 2024, entitled “Electronic Device”, the entire contents of which are incorporated herein by reference. Technical Field

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

[0003] Mobile phones and other electronic devices can achieve wireless communication through the antennas they contain. With the continuous development of communication technology and mobile phones and other electronic devices, these devices need to support an increasing number of operating frequency bands, and consequently, require more antennas within them.

[0004] The more antennas there are, the more space they occupy, and each antenna corresponds to at least one electrical connection point (the connection point that is electrically connected to the radio frequency device on the printed circuit board). Therefore, the conflict between the antenna electrical connection points and other functional architectures of the whole machine becomes more and more intense. Summary of the Invention

[0005] To address the aforementioned technical problems, this application provides an electronic device that can resolve the conflict between the electrical connection point of the antenna and other functional architectures of the entire device.

[0006] In a first aspect, embodiments of this application provide an electronic device, which is a foldable electronic device. The foldable electronic device includes: a first frame, at least a portion of which forms a first branch, the first branch being a radiator of an antenna; a first antenna for operating in at least two operating frequency bands; a second frame, at least a portion of which forms a second branch, wherein when the electronic device is in a folded state, the projection of the second branch along the thickness direction of the electronic device at least partially coincides with the projection of the first branch along the thickness direction of the electronic device; a flexible circuit board, the flexible circuit board being connected to the second branch and grounded; a first tuning circuit, the first tuning circuit being disposed on the flexible circuit board and electrically connected to the flexible circuit board; the first tuning circuit including multiple first tuning links, the first tuning circuit being used to enable the second branch to operate in at least two operating frequency bands; and the operating frequency band of the first antenna being different from the operating frequency band of the second branch.

[0007] By directly connecting the flexible circuit board to the frame, the conflict between the connection location of the second branch and other functional architectures in the electronic device can be resolved. This also saves on spring contacts and rigid circuit boards, freeing up more space for other structures and / or facilitating miniaturization and thinner design of the electronic device. Furthermore, saving spring contacts reduces one transition, thus avoiding increased system impedance due to transitions. Additionally, the first tuning circuit allows the second branch to operate in at least two frequency bands, rather than a fixed one. Since the first tuning circuit is located on the flexible circuit board, a separate structure to support it is unnecessary, simplifying the electronic device's structure.

[0008] For example, the flexible circuit board is the third flexible circuit board described below.

[0009] For example, the thickness direction of the electronic device is the thickness direction of the foldable electronic device when it is unfolded.

[0010] For example, the operating frequency band of the first antenna is different from that of the second stub, which can be the resonant frequency of the first antenna and the resonant frequency of the second stub. In this way, the second stub can act as a parasitic stub of the first antenna radiator to radiate energy, that is, the setting of the second stub can improve the radiation efficiency of the first antenna radiator.

[0011] According to the first aspect, the first tuning circuit includes a control terminal, which is used to receive different control signals and conduct different first tuning links based on the different control signals; when one of the multiple first tuning links is conducted, the second stub operates in at least one of the at least two operating frequency bands corresponding to the second stub.

[0012] In other words, based on the different control signals received by the control terminal of the first tuning circuit, different first tuning links are turned on. When different first tuning links are turned on, the second branch corresponds to a different operating frequency band. In this way, the radiator of the first ray will work in any of the at least two operating frequency bands, which will cause the second branch to radiate energy as a parasitic branch of the first ray radiator, thereby improving the radiation efficiency of the first ray radiator.

[0013] According to the first aspect, or any implementation of the first aspect above, the foldable electronic device includes a second tuning circuit connected to the first stub; the second tuning circuit includes a plurality of second tuning links, the second tuning circuit being configured to enable the first stub to operate in at least two operating frequency bands; when one of the plurality of second tuning links is turned on, the first stub operates in at least one of the at least two operating frequency bands corresponding to the first stub.

[0014] In other words, when different second tuning links are activated, the radiator of the first antenna operates in different frequency bands. Thus, the radiator of the first antenna can operate in at least two frequency bands, and the radiator of the first antenna can cover a wider bandwidth.

[0015] For example, the second tuning circuit includes a control terminal for receiving different control signals and activating different second tuning links based on the different control signals.

[0016] According to the first aspect, or any implementation of the first aspect above, at least a portion of the first frame further forms a third branch, the third branch being a radiator of the second antenna; the second antenna is used to operate in at least two operating frequency bands; at least a portion of the second frame further forms a fourth branch, the projection of the fourth branch along the thickness direction of the electronic device at least partially coinciding with the projection of the third branch along the thickness direction of the electronic device when the electronic device is in a folded state; the flexible circuit board is also connected to the fourth branch; the electronic device further includes a third tuning circuit disposed on the flexible circuit board and electrically connected to the flexible circuit board; the third tuning circuit includes multiple third tuning links, the third tuning circuit being used to enable the fourth branch to operate in at least two operating frequency bands; the operating frequency band of the second antenna is different from the operating frequency band of the fourth branch.

[0017] When an electronic device includes at least two antennas (such as a first antenna and a second antenna), each antenna can cover more frequency bands. Based on this, by setting corresponding parasitic branches for each antenna, the radiation efficiency of each antenna can be improved.

[0018] For example, the operating frequency band of the second antenna is different from that of the fourth stub, which can be the resonant frequency of the second antenna and the resonant frequency of the fourth stub. In this way, the fourth stub can act as a parasitic stub of the second antenna's radiator to radiate energy, that is, the setting of the fourth stub can improve the radiation efficiency of the second antenna's radiator.

[0019] According to the first aspect, or any implementation of the first aspect above, the foldable electronic device further includes a first functional device, a second branch and the first functional device are spaced apart, and a flexible circuit board is located on one side of the first functional device along the thickness direction of the electronic device.

[0020] Along the thickness direction of the electronic device, the flexible circuit board is disposed on one side of the first functional component. Compared to connecting to the second branch via a printed circuit board and spring contacts, and having the printed circuit board and spring contacts disposed on one side of the first functional component in the horizontal direction (perpendicular to the thickness direction of the electronic device), this saves horizontal space in the electronic device; furthermore, since the flexible circuit board is extremely thin, it does not affect the overall thickness of the electronic device. Alternatively,

[0021] Along the thickness direction of the electronic device, the flexible circuit board is disposed on one side of the first functional device. In this way, compared with connecting to the second branch through printed circuit boards and springs, and with the printed circuit boards and springs disposed on one side of the first functional device along the thickness direction of the electronic device, space in the thickness direction of the electronic device can be saved.

[0022] According to the first aspect, or any implementation of the first aspect above, the first functional device is a battery, a speaker, or a display screen, etc.

[0023] According to the first aspect, or any implementation of the first aspect above, the foldable electronic device further includes at least one second functional device, and the flexible circuit board is also connected to at least one second functional device.

[0024] This setup eliminates the need for a structure to receive corresponding signals for the second functional device, simplifying the structure of the electronic device and facilitating its thinner and lighter design.

[0025] For example, the second functional device may be the same as the first functional device, such as a speaker; the second functional device may also be a different device from the first functional device, such as a battery for the first functional device and a speaker for the second functional device.

[0026] For example, a foldable electronic device includes a plurality of second functional devices, and the flexible circuit board can be connected to one of the plurality of second functional devices; or it can be connected to at least two of the plurality of second functional devices. For example, a foldable electronic device includes three second functional devices, and the flexible circuit board can be connected to one second functional device; or it can be connected to two second functional devices; or it can be connected to all three second functional devices.

[0027] According to the first aspect, or any implementation of the first aspect above, the flexible circuit board is provided with a stress relief structure.

[0028] The stress relief structure can release the stress generated when the flexible circuit board deforms, preventing the flexible circuit board from deforming and breaking the circuit when the electronic device is subjected to large forces such as impact, and improving the reliability of the connection structure corresponding to the second branch.

[0029] According to the first aspect, or any implementation of the first aspect above, the flexible circuit board has a cutout portion, and the stress relief structure is the cutout portion; or, the flexible circuit board includes a redundant portion, and the stress relief structure is the redundant portion. This configuration simplifies the structure of the stress relief structure.

[0030] According to the first aspect, or any implementation of the first aspect above, the flexible circuit board includes a central portion, at least one first branch portion, and at least one second branch portion; the first branch portion is connected to the central portion, and the second branch portion is connected to the central portion or the first branch portion; the foldable electronic device further includes a signal processing module and at least one third functional device; the signal processing module is disposed on the central portion and electrically connected to the central portion; at least one first branch portion is connected to at least one third functional device, and at least one second branch portion is connected to a second branch.

[0031] This design eliminates the need for printed circuit boards inside electronic devices, avoiding the increased thickness that would result from such boards and promoting a thinner, lighter design.

[0032] For example, the signal processing module may include a processor, a baseband processor, an RF integrated circuit and / or an RF front-end module, etc.

[0033] For example, the third functional device may be the same as the first or second functional device, such as a speaker; or the third functional device may be a different device from the first or second functional device, such as a battery for the first functional device, a speaker for the second functional device, and a SIM card interface for the third functional device.

[0034] For example, the flexible circuit board includes a central portion, two first branch portions, and one second branch portion; the two first branch portions are respectively connected to two third functional devices, and the second branch portion is connected to a second stub. The number of second branch portions can be set according to the number of third functional devices, and the number of second branch portions can be set according to the number of second stubs.

[0035] According to the first aspect, or any implementation of the first aspect above, the flexible circuit board is connected to the second branch by conductive adhesive, silver paste or non-conductive adhesive; or, the flexible circuit board is connected to the second branch by a molten pool or hard interference.

[0036] In other words, the flexible circuit board can be connected to the second branch via direct connection (conductive adhesive or silver paste); it can also be connected via capacitive coupling (using non-conductive adhesive as a high dielectric constant connecting medium to attach one end of the flexible circuit board to the second branch); or it can be connected via rigid direct connection (molten pool or hard interference, etc.). Compared to connecting to the second branch in other ways, it occupies less space.

[0037] According to the first aspect, or any implementation of the first aspect above, the foldable electronic device further includes a connector, the connector including a first connector sub-component and a second connector sub-component connected to each other, and the plane where the first connector sub-component is located and the plane where the second connector sub-component is located have a preset angle, the first connector sub-component is connected to the flexible circuit board, and the second connector sub-component is connected to the second branch.

[0038] This design makes the solution of this application more widely applicable. Even if the strength of the flexible circuit board is relatively low, this solution can still be used to achieve the connection between the flexible circuit board and the second branch.

[0039] For example, the preset angle can be any angle between 60° and 120°, such as 60°, 70°, 80°, 90°, 100°, 110° or 120°.

[0040] For example, the connector may be a metal sheet, such as a steel sheet.

[0041] Secondly, embodiments of this application also provide an electronic device, comprising: a frame, at least a portion of which forms a first stub, the first stub being a radiator of an antenna; a first antenna for operating in at least two operating frequency bands; a flexible circuit board connected to the first stub and grounded; a second tuning circuit disposed on and electrically connected to the flexible circuit board; the second tuning circuit including multiple second tuning links, the second tuning circuit being used to enable the first stub to operate in at least two operating frequency bands.

[0042] By directly connecting the flexible circuit board to the frame, the conflict between the connection position of the first antenna radiator and other functional architectures in the electronic device can be resolved. This also saves on spring contacts and rigid circuit boards, freeing up more space for other structures and / or facilitating miniaturization and thinner design of the electronic device. Furthermore, saving spring contacts reduces one transition, thus avoiding increased system impedance due to transitions. Additionally, the second tuning circuit allows the first antenna radiator to operate in at least two frequency bands, enabling it to cover a wider range of frequencies. Since the second tuning circuit is located on the flexible circuit board, a separate structure to support it is unnecessary, simplifying the connection and overall structure of the electronic device.

[0043] For example, the flexible circuit board is the third flexible circuit board described below.

[0044] For example, the electronic device can be a candybar electronic device or a foldable electronic device.

[0045] According to the second aspect, the second tuning circuit includes a control terminal, which is used to receive different control signals and conduct different second tuning links based on the different control signals; when one of the multiple second tuning links is conducted, the first stub operates in at least one of the at least two operating frequency bands corresponding to the first stub.

[0046] In other words, based on the different control signals received by the control terminal of the second tuning circuit, different second tuning links are activated. When different second tuning links are activated, the operating frequency band of the first antenna radiator is different. In this way, the first antenna radiator can cover more frequency bands.

[0047] According to the second aspect, or any implementation of the second aspect above, at least a portion of the frame further forms a third branch, the third branch being a radiator of the second antenna; the second antenna is used to operate in at least two operating frequency bands; the flexible circuit board is also connected to the third branch; the electronic device further includes a fourth tuning circuit disposed on the flexible circuit board and electrically connected to the flexible circuit board; the fourth tuning circuit includes multiple fourth tuning links, the fourth tuning circuit being used to enable the third branch to operate in at least two operating frequency bands.

[0048] With this configuration, when the electronic device includes at least two antennas (such as a first antenna and a second antenna), each antenna can cover more frequency bands.

[0049] According to the second aspect, or any implementation of the second aspect above, at least a portion of the border also forms a third branch, which is also a radiator of the first antenna; the flexible circuit board is also connected to the third branch.

[0050] In other words, the flexible circuit board can connect multiple branches of the first antenna, and the fourth tuning circuit on the flexible circuit board can tune multiple branches of the first antenna through the flexible circuit board.

[0051] According to the second aspect, or any implementation of the second aspect above, the electronic device further includes a signal processing module, and the flexible circuit board is electrically connected to the signal processing module; the flexible circuit board is used to transmit the control signal sent by the signal processing module to the control terminal of the second tuning circuit; the flexible circuit board is also used to transmit the signal sent by the signal processing module to the first branch so as to radiate the signal through the first branch; or, the flexible circuit board is also used to transmit the signal received by the first branch to the signal processing module.

[0052] This configuration allows the flexible circuit board to transmit not only control signals but also signals sent by the signal processing module to the first stub, as well as electrical signals converted by the first stub and transmitted to the signal processing module. This eliminates the need for separate structures for transmitting control signals, signals sent by the signal processing module to the first stub, and electrical signals converted by the first stub to the signal processing module, simplifying the electronic device's structure. Furthermore, since the signals sent by the signal processing module are directly transmitted to the first stub—meaning the required signals reach the antenna directly—the impedance discontinuity in the signal-to-antenna path caused by the uncontrollable impedance of the spring contact can be optimized.

[0053] According to the second aspect, or any implementation of the second aspect above, the electronic device further includes a fourth functional device, the first branch and the fourth functional device are spaced apart, and the flexible circuit board is located on one side of the fourth functional device along the thickness direction of the electronic device.

[0054] Along the thickness direction of the electronic device, the flexible circuit board is disposed on one side of the fourth functional device. Compared to connecting to the first branch via a printed circuit board and spring contacts, and placing the printed circuit board and spring contacts on one side of the fourth functional device in the horizontal direction (perpendicular to the thickness direction of the electronic device), this saves space in the horizontal direction of the electronic device; furthermore, since the flexible circuit board is extremely thin, it does not affect the overall thickness of the electronic device. Alternatively,

[0055] Along the thickness direction of the electronic device, the flexible circuit board is disposed on one side of the fourth functional device. In this way, compared with connecting to the first branch through printed circuit boards and springs, and with the printed circuit boards and springs disposed on one side of the fourth functional device along the thickness direction of the electronic device, space in the thickness direction of the electronic device can be saved.

[0056] According to the second aspect, or any of the implementations of the second aspect above, the fourth functional device is a battery, a speaker, or a display screen, etc.

[0057] According to the second aspect, or any implementation of the second aspect above, the electronic device further includes at least one fifth functional device, and the flexible circuit board is also connected to at least one fifth functional device.

[0058] This setup eliminates the need for a structure to receive the corresponding signals for the fifth functional device, simplifying the structure of the electronic device and facilitating its thinner and lighter design.

[0059] For example, the fifth functional device may be the same as the fourth functional device, such as a speaker; or the fifth functional device may be a different device from the fourth functional device, such as a battery and a speaker.

[0060] For example, an electronic device includes a plurality of fifth functional devices, and the flexible circuit board can be connected to one of the fifth functional devices; or it can be connected to at least two of the fifth functional devices. For instance, an electronic device includes three fifth functional devices, and the flexible circuit board can be connected to one fifth functional device; or it can be connected to two fifth functional devices; or it can be connected to all three fifth functional devices.

[0061] According to the second aspect, or any implementation of the second aspect above, the flexible circuit board is provided with a stress relief structure.

[0062] The stress relief structure can release the stress generated when the flexible circuit board deforms, preventing the flexible circuit board from deforming and breaking the circuit when the electronic device is subjected to large forces such as impact, thereby improving the reliability of the connection structure corresponding to the antenna.

[0063] According to the second aspect, or any implementation of the second aspect above, the flexible circuit board has a cutout portion, and the stress relief structure is the cutout portion; or, the flexible circuit board includes a redundant portion, and the stress relief structure is the redundant portion. This configuration simplifies the structure of the stress relief structure.

[0064] According to the second aspect, or any implementation of the second aspect above, the flexible circuit board includes a central portion, at least one first branch portion, and at least one second branch portion; the first branch portion is connected to the central portion, and the second branch portion is connected to the central portion or the first branch portion; the electronic device further includes a signal processing module and at least one sixth functional device; the signal processing module is disposed on the central portion and electrically connected to the central portion; at least one first branch portion is connected to at least one sixth functional device, and at least one second branch portion is connected to the first branch.

[0065] This design eliminates the need for printed circuit boards inside electronic devices, avoiding the increased thickness that would result from such boards and promoting a thinner, lighter design.

[0066] For example, the signal processing module may include a processor, a baseband processor, an RF integrated circuit and / or an RF front-end module, etc.

[0067] For example, the sixth functional device may be the same as the fourth or fifth functional device, such as a speaker; or the sixth functional device may be a different device from the fourth or fifth functional device, such as a battery, a speaker, or a SIM card interface.

[0068] For example, the flexible circuit board includes a central portion, two first branch portions, and one second branch portion; the two first branch portions are respectively connected to two third functional devices, and the second branch portion is connected to a second stub. The number of second branch portions can be set according to the number of third functional devices, and the number of second branch portions can be set according to the number of second stubs.

[0069] According to the second aspect, or any implementation of the second aspect above, the material of the frame includes a non-conductive structural material, the flexible circuit board is connected to the frame, and the part where the flexible circuit board is connected to the frame is reused as the first branch.

[0070] This design makes the solution provided in this application more widely applicable; that is, even if the frame material is a non-conductive structural material, it will not affect the performance of the antenna.

[0071] According to the second aspect, or any implementation of the second aspect above, the material of the frame includes a non-conductive structural material, and a first branch is provided on the side wall of the frame.

[0072] That is, a first branch is set separately on the frame. This setting makes the solution provided in this application more widely applicable. That is, even if the frame material is a non-conductive structural material, it will not affect the performance of the antenna.

[0073] According to the second aspect, or any implementation of the second aspect above, the material of the border includes polyimide or polyethylene terephthalate.

[0074] In other words, the frame is made of a flexible material (i.e., the frame is a flexible frame), and when combined with a flexible circuit board and a flexible display screen, flexible electronic devices can be formed.

[0075] According to the second aspect, or any implementation of the second aspect above, the electronic device includes a flexible electronic device.

[0076] According to the second aspect, or any implementation of the second aspect above, the flexible circuit board is connected to the first branch by conductive adhesive, silver paste or non-conductive adhesive; or, the flexible circuit board is connected to the first branch by a molten pool or hard interference.

[0077] In other words, the flexible circuit board can be connected to the first branch via direct connection (conductive adhesive or silver paste); it can also be connected via capacitive coupling (using non-conductive adhesive as a high dielectric constant connecting medium to attach one end of the flexible circuit board to the first branch); or it can be connected via rigid direct connection (molten pool or hard interference, etc.). Compared to connecting to the first branch in other ways, it occupies less space.

[0078] According to the second aspect, or any implementation of the second aspect above, the electronic device further includes a connector, which includes a first connector sub-component and a second connector sub-component connected to each other, and the plane where the first connector sub-component is located and the plane where the second connector sub-component is located have a preset angle, the first connector sub-component is connected to the flexible circuit board, and the second connector sub-component is connected to the first branch.

[0079] This design makes the solution of this application more widely applicable. Even if the strength of the flexible circuit board is relatively low, this solution can still be used to achieve the connection between the flexible circuit board and the first branch.

[0080] For example, the preset angle can be any angle between 60° and 120°, such as 60°, 70°, 80°, 90°, 100°, 110° or 120°.

[0081] For example, the connector may be a metal sheet, such as a steel sheet. Attached Figure Description

[0082] Figure 1 is a schematic diagram of the structure of an electronic device;

[0083] Figure 2 is a schematic diagram of the structure of another electronic device;

[0084] Figure 3a is a state diagram of an electronic device;

[0085] Figure 3b shows another state diagram of an electronic device;

[0086] Figure 4 shows the positional relationship of the structures in region AA of Figure 2;

[0087] Figure 5 is a schematic diagram of the structure of an electronic device provided in an embodiment of this application;

[0088] Figure 6 is a cross-sectional view of the electronic device shown in Figure 5 along the BB' direction;

[0089] Figure 7 is a diagram showing the positions of some functional components inside the electronic device shown in Figure 5;

[0090] Figure 8 is a circuit diagram of a wireless communication circuit provided in an embodiment of this application;

[0091] Figure 9 is a connection diagram of the tuning circuit provided in the embodiment of this application;

[0092] Figure 10 shows the positional relationship of some structures within the CC region of Figure 7;

[0093] Figure 11 is a cross-sectional view along the DD' direction in Figure 10;

[0094] Figure 12 is a cross-sectional view along the EE' direction in Figure 10;

[0095] Figure 13 shows the circuit diagram corresponding to the conductor;

[0096] Figure 14 is another diagram showing the positional relationship of some functional components inside the electronic device shown in Figure 5;

[0097] Figure 15 is a diagram showing the positional relationship between the third flexible circuit board and each conductor provided in an embodiment of this application.

[0098] Figure 16 is a diagram showing the positional relationship between the third flexible circuit board and the radiator corresponding to the first antenna and the radiator corresponding to the second antenna provided in the embodiments of this application.

[0099] Figure 17 is a cross-sectional view of the electronic device shown in Figure 5 along the FF' direction;

[0100] Figure 18 is a positional relationship diagram of the third flexible circuit board, functional devices, and tuning circuit provided in an embodiment of this application;

[0101] Figure 19 is another positional relationship diagram of the third flexible circuit board, functional device and tuning circuit provided in the embodiment of this application;

[0102] Figure 20 is another positional relationship diagram of the third flexible circuit board, functional device and tuning circuit provided in the embodiment of this application;

[0103] Figure 21 is another positional relationship diagram of the third flexible circuit board, functional device and tuning circuit provided in the embodiment of this application;

[0104] Figure 22 is a diagram showing a positional relationship between the third flexible circuit board and the metal frame provided in an embodiment of this application.

[0105] Figure 23 is a diagram showing the positional relationship between the third flexible circuit board, connector, and conductor provided in an embodiment of this application.

[0106] Figure 24a is a top view of a third flexible circuit board provided in an embodiment of this application;

[0107] Figure 24b is a side view of a third flexible circuit board provided in an embodiment of this application;

[0108] Figure 25 is a diagram showing the connection relationship between a third flexible circuit board and various functional devices provided in an embodiment of this application;

[0109] Figure 26 is another diagram showing the positional relationship of some functional components inside the electronic device shown in Figure 5;

[0110] Figure 27 is a top view showing the positional relationship of the fourth flexible circuit board, the radiator of the antenna, the frame, and the middle plate provided in this application.

[0111] Figure 28 is a top view showing another positional relationship between the fourth flexible circuit board, the radiator of the antenna, the frame, and the middle plate provided in this application.

[0112] Figure 29 is a cross-sectional view of the electronic device shown in Figure 28 along the FF' direction;

[0113] Figure 30 is a top view showing another positional relationship between the fourth flexible circuit board, the radiator of the antenna, the frame, and the middle plate provided in this application.

[0114] Figure 31 is a cross-sectional view of the electronic device shown in Figure 30 along the GG' direction;

[0115] Figure 32 is a schematic diagram of the structure of another electronic device provided in an embodiment of this application. Detailed Implementation

[0116] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0117] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0118] The terms "first" and "second," etc., used in the specification and claims of this application are used to distinguish different objects, not to describe a specific order of objects. For example, "first target object" and "second target object," etc., are used to distinguish different target objects, not to describe a specific order of target objects.

[0119] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0120] In the description of the embodiments in this application, unless otherwise stated, "multiple" means two or more. For example, multiple processing units means two or more processing units; multiple systems means two or more systems.

[0121] In describing some embodiments, the term "connection" and its derivative expressions may be used. For example, the term "connection" may be used in describing some embodiments to indicate that two or more components are in direct physical or electrical contact with each other.

[0122] Electronic devices may be equipped with wireless communication circuits to support their wireless communication functions. These wireless communication circuits include an antenna system, which comprises an antenna and a feed source.

[0123] For example, referring to Figure 1, which is a schematic diagram of the structure of an electronic device, Figure 1 illustrates the electronic device as a candybar mobile phone. In the example shown in Figure 1, the mobile phone may have a metal frame, and the antenna system 1 can reuse the metal frame as the radiator of the antenna (the structure in the antenna used to receive or transmit electromagnetic wave radiation) 2. Specifically, based on the required length of the radiator of the antenna, a through-slit is reasonably set on the metal frame, thereby obtaining an independent metal frame as the radiator 2 of the antenna.

[0124] One end of the radiator 2 of the antenna can be connected to the feed source 3, and the other end is grounded. The feed source 3 can be used to provide a transmitted signal in a transmitting scenario, or to receive an electrical signal acquired by the radiator 2 of the antenna in a receiving scenario. The operating frequency band of the antenna can include at least a portion of the operating frequency band corresponding to wireless communication. For example, the operating frequency band can include cellular communication frequency bands (such as 700MHz-3GHz), short-range communication frequency bands (such as 2.4GHz Bluetooth, 2.4G WIFI, 5G WIFI related frequency bands, etc.), and other wireless communication frequency bands. When the antenna system 1 is working, for example, in a transmitting scenario, the radiator 2 of the antenna can convert the feed signal from the feed source 3 into an electromagnetic wave for radiation; or, for example, in a receiving scenario, the radiator 2 of the antenna can receive the electromagnetic wave and convert it into an electrical signal for transmission to the feed source 3, so that the radio frequency devices connected to the feed source 3 (such as radio frequency front-end modules, radio frequency integrated circuits and / or baseband processors, etc., as described below) can determine the information carried in the electromagnetic wave based on the electrical signal.

[0125] It is understood that antenna system 1, as shown in Figure 1, can be used to cover part or all of the wireless communication frequency band of the electronic device. When antenna system 1 cannot cover all of the wireless communication frequency band of the electronic device, multiple antenna systems operating in different frequency bands can be installed in the electronic device.

[0126] In the example shown in Figure 1, the electronic device is described as a candybar electronic device (such as a candybar mobile phone). In other optional embodiments of this application, the electronic device can also be a foldable electronic device. For example, see Figure 2, which is a structural schematic diagram of another electronic device, wherein Figure 2 illustrates a foldable electronic device as a foldable mobile phone. In the example shown in Figure 2, the foldable mobile phone includes a first frame 4, a second frame 5, and a pivot 6 located between the first frame 4 and the second frame 5. By rotating the pivot 6, different states of the foldable mobile phone can be achieved, such as an unfolded state (as shown in Figure 2), a folded state (as shown in Figure 3a), and a hovering state between the folded and unfolded states (as shown in Figure 3b). The first frame 4 and the second frame 5 can have metal frames, so the antenna system 1 can reuse the metal frame of the first frame 4 as the radiator 2 of the antenna. Specifically, based on the required length of the radiator of the antenna, a through-slit is reasonably set on the metal frame of the first frame 4, thereby obtaining an independent metal frame as the radiator 2 of the antenna. One end of the radiator 2 of the antenna can be connected to the feed 3, and the other end is grounded.

[0127] In some embodiments, referring again to Figures 2 and 3, a through-slit is also provided on the metal frame of the second frame 5 to form a conductor 8. When the foldable phone is in the folded state, the conductor 8 overlaps with the radiator 2 of the first frame 4. When the foldable phone is in the folded state, because the conductor 8 is close to the radiator 2 of the antenna and the distance between them is small, when the radiator 2 of the antenna is fed, an electric field coupling occurs between the radiator 2 and the conductor 8, thereby exciting a current in the conductor 8. The current directions on the radiator 2 and the conductor 8 are opposite, while the electric fields generated by the radiator 2 and the conductor 8 in the gap between them are in the same direction. This current and electric field distribution characteristic is similar to the current and electric field distribution characteristics on a dual conductor in a transmission line mode, belonging to the closed field type, which is an energy storage and dissipation mode. The energy of the electric field generated in the gap between the radiator 2 and the conductor 8 is stored in the cavity jointly constructed by the first frame 4, the second frame 5, and the pivot 6 in the folded state, resulting in a decrease in the radiation efficiency of the radiator 2 of the antenna and affecting the communication performance of the foldable electronic device.

[0128] To improve the radiation efficiency of the antenna radiator 2, a tuning point 7 is provided in the second frame 5. The tuning point 7 is connected to the conductor 8 through a matching device (such as a capacitor or inductor) 71. Specifically, the tuning point 7 can receive the signal coupled from the feed 3. The matching device 71 modulates the frequency of the signal coupled to the tuning point 7, so that the resonant frequency of the signal transmitted to the conductor 8 is different from that of the signal on the antenna radiator 2. In this way, the conductor 8 can act as a parasitic branch of the antenna radiator 2, radiating the energy coupled from the feed 3 and improving the radiation efficiency of the antenna radiator 2.

[0129] It should be noted that when the foldable phone is in the folded state, the tuning point 7 can correspond to the feed source 3. That is, when the foldable phone is in the folded state, the projection of the tuning point 7 in the second frame 5 along the thickness direction of the electronic device coincides with the projection of the feed source 3 in the first frame 4 along the thickness direction of the electronic device. This coincidence can be partial or complete. When the tuning point 7 corresponds to the feed source 3, the tuning point 7 can couple more signals from the feed source 3, thus transmitting more energy to the conductor 8, and consequently, radiating more energy, further improving the radiation efficiency of the antenna radiator 2. In some optional embodiments, the tuning point 7 may not correspond to the feed source 3. That is, when the foldable phone is in the folded state, the projection of the tuning point 7 in the second frame 5 along the thickness direction of the electronic device does not coincide with the projection of the feed source 3 in the first frame 4 along the thickness direction of the electronic device.

[0130] As the background technology shows, the number of antennas is increasing, the space occupied is getting larger and larger, and each antenna corresponds to at least one or more electrical connection points (i.e., feed sources). When the electronic device is a foldable phone, corresponding tuning points also need to be set. For electronic devices with the need for thinness and lightness, the conflict between the antenna electrical connection points and / or tuning points and other functional architectures is becoming more and more intense.

[0131] For example, taking the above-mentioned foldable electronic device as an example, the second frame 5 is provided with a functional device, such as a speaker, at the position of the feed source 3 in the first frame 4 (that is, the setting position of the tuning point 7). In other words, there is a layout conflict between the setting position of the tuning point 7 and the setting position of the speaker.

[0132] To avoid layout conflicts between the location of tuning point 7 and the location of the speaker, in some embodiments, as shown in Figure 4 (which is a diagram of the positional relationship of the structures in area AA of Figure 2), the location where tuning point 7 should be located is where speaker 9 is located. To receive the signal coupled from feed source 3, tuning point 7 and matching device 71 can be set on circuit board 11. The signal coupled by tuning point 7 is frequency-modulated by matching device 71 and can then be connected to conductor 8 via flexible circuit board. Specifically, one end of flexible circuit board 10 is connected to circuit board 11 with matching device 71 via a spring contact, and the other end of flexible circuit board 10 is connected to circuit board 12 across speaker 9 via a connection structure (such as a board-to-board connector). Circuit board 12 is connected to conductor 8 via spring contact 13. The signal coupled by tuning point 7 is frequency-modulated by matching device 71 and then transmitted to conductor 8 via flexible circuit board 10, circuit board 12, and spring contact 13 (the transmission path is shown by the dashed arrow in Figure 4), thus avoiding layout conflicts between the location of tuning point 7 and the location of speaker 9.

[0133] However, this also presents some problems. Referring to Figure 4, since a circuit board 12 and a spring 13 need to be placed between the speaker 9 and the conductor 8, the placement of the circuit board 12 and the spring 13 occupies a large volume, which cannot be utilized by the speaker 9. This is not conducive to increasing the size of the rear cavity of the speaker 9, and thus cannot improve the sound effect of the speaker 9.

[0134] It should be noted that the above explanation uses the conflict between the tuning point 7 and the speaker 9 in a foldable phone as an example, but this does not constitute a limitation of this application. In some alternative embodiments, the feed 3 in a foldable phone may also conflict with other functional components within the first frame 4; or, the feed 3 in a candybar phone may also conflict with other functional components within it. To avoid this conflict, the feed 3 may be placed in another location, and the signal received by the feed 3 may be transmitted to the radiator 2 of the antenna via a flexible circuit board, a circuit board, and spring contacts. However, the placement of these circuit boards and spring contacts will occupy a significant amount of space.

[0135] To address the issue of bulky designs using circuit boards and spring clips to connect to the frame, this application provides a technical solution that directly connects the antenna to the frame via a flexible circuit board. This resolves conflicts between antenna placement and other functional architectures in the electronic device, saves on spring clips and circuit boards, freeing up more space for other structures and / or facilitating miniaturization and thinner design of the electronic device. Furthermore, saving on spring clips reduces one transition, thus avoiding increased system impedance due to transitions. And since the required signal reaches the antenna directly, this optimizes the impedance discontinuity in the signal path to the antenna caused by the uncontrollable impedance of the spring clips.

[0136] The technical solutions provided in this application can be applied to electronic devices. In different implementations, the electronic device may include at least one of the following: mobile phone, tablet computer, desktop computer, laptop computer, handheld computer, notebook computer, ultra-mobile personal computer (UMPC), netbook, cellular phone, personal digital assistant (PDA), augmented reality (AR) device, virtual reality (VR) device, artificial intelligence (AI) device, wearable device, in-vehicle device, smart home device, or smart city device. Furthermore, the electronic device can be a candybar electronic device, such as the electronic device corresponding to Figure 1 in the aforementioned examples; or it can be a foldable electronic device, such as the electronic device corresponding to Figure 2 in the aforementioned examples. This application does not impose any special limitations on the specific type and form of the electronic device.

[0137] The technical solutions provided by the embodiments of this application will be described in detail below with reference to the accompanying drawings. Unless otherwise specified, the following description uses a foldable mobile phone as the electronic device and the layout conflict between the tuning point and the speaker in the foldable mobile phone as an example. It is understood that although the above example is based on the layout conflict between the tuning point and the speaker in a foldable mobile phone, this does not constitute a limitation on this application. This technical solution can be used for any conflict between the connection position connected to the frame and other functional architectures in the electronic device. It is not limited to the layout conflict between the tuning point and the speaker in a foldable mobile phone. For example, this technical solution can also be used when there is a layout conflict between the feed source 3 and other functional components in the electronic device.

[0138] Referring to Figure 5, which is a schematic diagram of the structure of an electronic device provided in an embodiment of this application, in the example shown in Figure 5, the foldable phone includes, in addition to the first frame 4, the second frame 5, and the pivot 6 located between the first frame 4 and the second frame 5 as described above, a flexible display screen 14. The first frame 4, the second frame 5, and the pivot 6 are used to jointly support the flexible display screen 14.

[0139] The flexible display screen 14 is a flexible display screen. The flexible display screen 14 may include an organic light-emitting diode (OLED) display screen. OLED displays do not require a backlight module, and the substrate in the OLED display screen can be made of a flexible resin material, such as polyethylene terephthalate (PET), giving the OLED display screen a bendable characteristic. Of course, the type of flexible display screen 14 includes, but is not limited to, OLED displays; any display screen that can be bent is within the scope of protection of this application, such as a liquid crystal display (LCD) screen, an LED display screen (e.g., including Micro-LED displays, Mini-LED displays), etc.

[0140] The flexible display screen 14 can be divided into different parts. When folded, the part of the flexible display screen 14 that bends is the bent display segment 142, which is opposite to the pivot 6. In the flexible display screen 14, the parts located on both sides of the bent display segment 142 are the first flat display segment 141 and the second flat display segment 143, respectively. The first flat display segment 141 is opposite to the first frame 4, and the second flat display segment 143 is opposite to the second frame 5. During the rotation of the pivot 6, the foldable phone can transition from an unfolded state to a folded state. This means the angle between the plane containing the first flat display segment 141 and the plane containing the second flat display segment 143 changes as the bent display segment 142 bends, for example, from 180° to 0°. When the angle between the plane containing the first flat display segment 141 and the plane containing the second flat display segment 143 is 180° (i.e., the unfolded state), the first flat display segment 141, the bent display segment 142, and the second flat display segment 143 can form a complete display plane, giving the foldable electronic device a large display area and enabling large-screen display functionality to meet users' needs for large-screen displays. When the angle between the plane containing the first flat display segment 141 and the plane containing the second flat display segment 143 is 0° (i.e., the folded state), it meets the user's need for easy portability.

[0141] Referring to Figure 6, which is a cross-sectional view of the electronic device shown in Figure 5 along the BB' direction, the flexible display screen 14 includes a display panel 14a and a cover plate 14b located on one side of the display panel 14. The cover plate 14b is used to protect the display panel 14a and improve its scratch resistance and impact resistance.

[0142] The first frame 4 includes a first outer shell 41 and a first middle frame 42, and the second frame 5 includes a second outer shell 51 and a second middle frame 52.

[0143] The first outer casing 41 can be the back cover of a foldable phone (also called a battery cover); it can also be a display screen for display purposes, and this embodiment of the application does not limit this. The second outer casing 51 can be the back cover of a foldable phone (also called a battery cover); it can also be a display screen for display purposes, and this embodiment of the application does not limit this.

[0144] The first middle frame 42 includes a first frame (the structure exposed on the outer side of the first middle frame 42) 421 and a first middle plate 422 located between the first flat display segment 141 and the first outer shell 41. The first frame 421 and the first middle plate 422 are fixedly connected. The first frame 421 and the first middle plate 422 can be integrally formed or separately formed and then fixed together by welding or bonding. The second middle frame 52 includes a second frame (the structure exposed on the outer side of the second middle frame 52) 521 and a second middle plate 522 located between the second flat display segment 143 and the second outer shell 51. The second frame 521 and the second middle plate 522 are fixedly connected. The second frame 521 and the second middle plate 522 can be integrally formed or separately formed and then fixed together by welding or bonding.

[0145] The first frame 421 and the second frame 521 are both annular. The first flat display segment 141, the first frame 421, and the first outer shell 41 form a first receiving cavity, and the first middle plate 422 is located in the first receiving cavity. The second flat display segment 143, the second frame 521, and the second outer shell 51 form a second receiving cavity, and the second middle plate 522 is located in the second receiving cavity.

[0146] The first intermediate plate 422 and the second intermediate plate 522 both have a first surface M1 on the side closest to the flexible display screen 14, and both have a second surface M2 on the side away from the flexible display screen 14. The cover plate 14b is located on the side of the display panel 14a away from the first surface M1 of the first intermediate plate 422 and the second intermediate plate 522.

[0147] Referring to Figure 7, which is a diagram showing the positional relationship of the functional components inside the electronic device shown in Figure 5, the foldable phone also includes components such as a first printed circuit board 15, a second printed circuit board 16, a third printed circuit board 17, a fourth printed circuit board 18, a first battery 19, a second battery 20, a first flexible circuit board 21, a second flexible circuit board 22, a subscriber identification module (SIM) card interface 90, and a speaker 9. Processors are provided on the first printed circuit board 15, the second printed circuit board 16, the third printed circuit board 17, and / or the fourth printed circuit board 18.

[0148] It is understood that Figure 7 and the related accompanying drawings below only schematically show some of the components included in a foldable phone, and the actual shape, size, position, and construction of these components are not limited to Figure 7 and the accompanying drawings below. Furthermore, when the electronic device is of other forms, it may not include at least one of the following: first frame 4, second frame 5, hinge 6, flexible display 14, first printed circuit board 15, second printed circuit board 16, third printed circuit board 17, fourth printed circuit board 18, first battery 19, second battery 20, first flexible circuit board 21, second flexible circuit board 22, SIM card interface 90, speaker 9, etc.

[0149] The first and / or second accommodating cavities are used to accommodate components such as the first printed circuit board 15, the second printed circuit board 16, the third printed circuit board 17, the fourth printed circuit board 18, the first battery 19, the second battery 20, the first flexible circuit board 21, the second flexible circuit board 22, the SIM card interface 90, and the speaker 9.

[0150] In some embodiments, the first printed circuit board 15, the second printed circuit board 16, the first battery 19, and the first flexible circuit board 21 are located in the first receiving cavity, while the third printed circuit board 17, the fourth printed circuit board 18, the second battery 20, the second flexible circuit board 22, the SIM card interface 90, and the speaker 9 are located in the second receiving cavity.

[0151] It should be noted that the above-mentioned settings do not constitute a limitation on this application. The embodiments of this application are illustrated by taking the first printed circuit board 15, the second printed circuit board 16, the first battery 19 and the first flexible circuit board 21 as being located in the first receiving cavity, and the third printed circuit board 17, the fourth printed circuit board 18, the second battery 20, the second flexible circuit board 22, the SIM card interface 90 and the speaker 9 as being located in the second receiving cavity.

[0152] Referring again to Figure 7, the first printed circuit board 15, the second printed circuit board 16, the first battery 19, and the first flexible circuit board 21 are all located between the second surface M2 of the first middle plate 422 and the first outer shell 41; the third printed circuit board 17, the fourth printed circuit board 18, the second battery 20, the second flexible circuit board 22, the SIM card interface 90, and the speaker 9 are located between the second surface M2 of the second middle plate 522 and the second outer shell 51.

[0153] In some embodiments, the second surface M2 of the first intermediate plate 422 has a first battery compartment (not shown in the figure), and the first battery 19 is installed in the first battery compartment; the second surface M2 of the second intermediate plate 522 has a second battery compartment (not shown in the figure), and the second battery 20 is installed in the second battery compartment.

[0154] The first printed circuit board 15 and the second printed circuit board 16 are respectively disposed on both sides of the first battery 19. The first flexible circuit board 21 is located between the first battery 19 and the first outer casing 41, and the two ends of the first flexible circuit board 21 are respectively connected to the first printed circuit board 15 and the second printed circuit board 16. The first flexible circuit board 21 can realize the transmission of signals between the first printed circuit board 15 and the second printed circuit board 16.

[0155] The third printed circuit board 17 and the fourth printed circuit board 18 are respectively disposed on both sides of the second battery 20. The second flexible circuit board 22 is located between the second battery 20 and the second housing 51, and its two ends are respectively connected to the third printed circuit board 17 and the fourth printed circuit board 18. Signal transmission between the third printed circuit board 17 and the fourth printed circuit board 18 can be realized through the second flexible circuit board 22.

[0156] The SIM card interface 90 and the speaker 9 are located on the same side of the second battery 20 as the fourth printed circuit board 18.

[0157] The first frame 421 and the second frame 521 can be metal frames, wherein the material of the metal frame includes, but is not limited to, aluminum alloy, stainless steel, steel-aluminum composite die-cast plate, or titanium alloy. Of course, this does not constitute a limitation of this application, the first frame 421 and the second frame 521 can also be non-metallic frames, such as ceramic frames or glass frames.

[0158] Accordingly, the first intermediate plate 422 and the second intermediate plate 522 can be metal intermediate plates, wherein the material of the metal intermediate plate includes, but is not limited to, aluminum alloy, stainless steel, steel-aluminum composite die-cast plate, or titanium alloy. Of course, this does not constitute a limitation of this application, and the first intermediate plate 422 and the second intermediate plate 522 can also be non-metallic intermediate plates, such as ceramic intermediate plates or glass intermediate plates.

[0159] In addition, the foldable electronic device also includes a through-shaft flexible circuit board (not shown in the figure). One end of the through-shaft flexible circuit board can be connected to the first printed circuit board 15 or the second printed circuit board 16 in the first receiving cavity through a connection structure (such as a board-to-board connector). The other end of the through-shaft flexible circuit board passes through the pivot 6 and is connected to the third printed circuit board 17 or the fourth printed circuit board 18 in the second receiving cavity through another connection structure (such as a board-to-board connector). This allows the printed circuit boards in the first receiving cavity and the second receiving cavity to be connected. The through-shaft flexible circuit board enables signal transmission between the printed circuit boards in the first receiving cavity and the printed circuit boards in the second receiving cavity.

[0160] In this embodiment, the foldable electronic device also has wireless communication functionality. Accordingly, the foldable electronic device further includes a wireless communication circuit 23. Referring to Figure 8, which is a circuit diagram of a wireless communication circuit provided in this embodiment, the wireless communication circuit 23 includes not only the antenna system 1 described above, but also a radio frequency front-end module (RFFEM) 231, a radio frequency integrated circuit (RFIC) 232, and a baseband processor 233. The RFFEM 231, RFIC 232, and baseband processor 233 can be disposed on a first printed circuit board 15 of the first accommodating cavity. The first printed circuit board 15 connects the RFFEM 231, RFIC 232, and baseband processor 233.

[0161] Antenna system 1 includes at least one antenna and at least one feed, each antenna including at least one antenna radiator. When the frame is a metal frame, the metal frame can serve as the antenna radiator 2. As described above, based on the required length of the antenna radiator, a through-slit can be reasonably provided on the metal frame to obtain an independent metal frame for use as the antenna radiator 2. For example, the first frame 421 has slits a and b near the second printed circuit board 16, which separate the first frame 421 into an independent metal frame (also referred to as the first stub) serving as the antenna radiator 2. The feed 3 can be connected to the second printed circuit board 16, and the feed 3 is connected to the RF front-end module 231 on the first printed circuit board 15 via the second printed circuit board 16 and the first flexible circuit board 21. The antenna radiator 2 can be connected to the feed 3 via a connecting structure such as a spring clip (not shown in the figure). The radiator 2 of the antenna is also grounded. For example, the radiator 2 of the antenna is connected to the grounding point on the printed circuit board (first printed circuit board 15 or second printed circuit board 16) through a grounding component (not shown in the figure); or, the first intermediate plate 422 is a metal intermediate plate, and the metal intermediate plate is connected to the grounding point of the printed circuit board (first printed circuit board 15 or second printed circuit board 16). In this way, the metal intermediate plate can be used as a reference ground, so the grounding component can be directly connected to the metal intermediate plate to achieve grounding.

[0162] For example, in a transmission scenario, the baseband processor 233 synthesizes the data (digital signal) to be transmitted into a baseband signal to be transmitted, and modulates the baseband signal into a baseband modulated signal and sends it to the radio frequency integrated circuit 232. The radio frequency integrated circuit 232 converts the baseband modulated signal into a transmission signal. After the transmission signal is mixed, amplified, filtered and processed by the radio frequency front-end module 231, it is transmitted to the feed source 3 through the first flexible circuit board 21 and the second printed circuit board 16. The radiator 2 of the antenna can convert the feed signal from the feed source 3 into electromagnetic waves for radiation.

[0163] For example, in a receiving scenario, the radiator 2 of the antenna can receive electromagnetic waves and convert them into electrical signals, which are then transmitted to the feed 3. The signals are then transmitted to the RF front-end module 231 on the first printed circuit board 15 via the second printed circuit board 16 and the first flexible circuit board 21 connected to the feed 3. In the RF front-end module 231, the signal is switched to the corresponding receiving link by a device with a switching function. After the signal is amplified, filtered, mixed, and processed by the receiving link, it is sent to the RF integrated circuit 232. The RF integrated circuit 232 processes the signal into a baseband modulated signal and transmits it to the baseband processor 233. The baseband processor 233 converts the baseband modulated signal into a baseband signal and then converts the baseband signal into data to determine the information carried in the electromagnetic wave.

[0164] In some embodiments, to enable the antenna to cover a wider bandwidth, referring to Figures 7 and 9, Figure 9 is a connection diagram of the tuning circuit provided in this embodiment. The antenna system 1 further includes a resonant circuit 25, which is disposed adjacent to the radiator 2 of the antenna. The resonant circuit 25 includes at least one control terminal Con1, one ground terminal Gnd1, and multiple tuning terminals. Multiple tuning links are provided within the tuning circuit 25, with one end of each tuning link connected to one of the multiple tuning terminals. The other end of each tuning link is connected to the ground terminal Gnd1. The radiator 2 of the antenna is connected to the multiple tuning terminals e1 of the resonant circuit 25. The ground terminal Gnd1 of the resonant circuit 25 can be directly connected to the metal middle plate through a grounding component or other connection structure to achieve grounding. The control terminal Con1 of the resonant circuit 25 is used to connect different links. The resonant tuning 25 conducts different tuning links based on different control signals received by its control terminal Con1. The resonant frequency band of the radiator 2 of the antenna is tuned through the conducted tuning links, wherein different tuning links correspond to different resonant frequency bands. In this way, the bandwidth of the radiator 2 of the antenna can cover a wider bandwidth, such as the entire bandwidth of 700-960MHz.

[0165] It should be noted that the specific structure of the tuning link is not limited in the embodiments of this application. For example, the tuning link may include switches and matching devices, and the matching devices may include inductors and / or capacitors, etc. The switches of each tuning link are connected to the control terminal Con1 of the resonant circuit 25. Different switches are turned on based on different control signals received by the control terminal Con1, thereby turning on different tuning links.

[0166] For example, there are three tuning terminals: a first tuning terminal e11, a second tuning terminal e12, and a third tuning terminal e13. Correspondingly, there are multiple tuning links, including a first tuning link, a second tuning link, and a third tuning link. The first tuning link includes a first switch 251 and a first matching device 254; the second tuning link includes a second switch 252 and a second matching device 255; and the third tuning link includes a third switch 253 and a third matching device 256. The first matching device 254 is connected to one end of the first tuning terminal e11 and one end of the first switch 251, the second matching device 255 is connected to one end of the second tuning terminal e12 and one end of the second switch 252, and the third matching device 256 is connected to one end of the third tuning terminal e13 and one end of the third switch 253. The other ends of the first switch 251, the second switch 252, and the third switch 253 are all connected to the ground terminal Gnd1. The radiator 2 of the antenna is connected to the first tuning terminal e11, the second tuning terminal e12, and the third tuning terminal e13 of the resonant circuit 25. The control signal received by the control terminal Con1 of the resonant circuit 25 includes a first control signal, a second control signal, and a third control signal. When the control signal received by the control terminal Con1 of the resonant circuit 25 is the first control signal, the first switch 251 is turned on, and the first matching device 254 is grounded. The first matching device 254 tunes the resonant frequency band of the radiator 2 of the antenna, such as tuning to the first resonant frequency band. When the control signal received by the control terminal Con1 of the resonant circuit 25 is the second control signal, the second switch 252 is turned on, and the second matching device 255 is grounded. The second matching device 255 tunes the resonant frequency band of the radiator 2 of the antenna, such as tuning to the second resonant frequency band. When the control signal received by the control terminal Con1 of the resonant circuit 25 is the third control signal, the third switch 253 is turned on, and the third matching device 256 is grounded. The third matching device 256 tunes the resonant frequency band of the radiator 2 of the antenna, such as tuning it to the third resonant frequency band. In this way, the bandwidth of the radiator 2 of the antenna can cover a wider bandwidth.

[0167] For example, when the foldable phone needs to support GSM 900MHz, the control signal received by the control terminal Con1 of the resonant circuit 25 is the first control signal, the first switch 251 is turned on, and the first matching device 254 is grounded. The first matching device 254 tunes the resonant frequency band of the radiator 2 of the antenna, such as tuning it to 890MHz to 915MHz. When the foldable phone needs to support GSM 850MHz, the control signal received by the control terminal Con1 of the resonant circuit 25 is the second control signal, the second switch 252 is turned on, and the second matching device 255 is grounded. The second matching device 255 tunes the resonant frequency band of the radiator 2 of the antenna, such as tuning it to 835MHz to 890MHz. In this way, the bandwidth of the radiator 2 of the antenna can cover not only 890MHz to 915MHz, but also 835MHz to 890MHz.

[0168] The control signal received by the control terminal Con1 of the resonant circuit 25 can be provided by a processor located on the first printed circuit board 15. That is, the processor outputs a control signal, which can be transmitted to the control terminal Con1 of the resonant circuit 25 through the first printed circuit board 15, the first flexible circuit board 21, and the second printed circuit board 16. Of course, this does not constitute a limitation of this application, and it can also be provided by other devices with control functions (such as the radio frequency integrated circuit 232) in the foldable electronic device.

[0169] As mentioned above, the metal frame of the second frame 5 also has through-slits (slits c and d in Figure 9), forming a conductor 8 (also called the second stub). To improve the radiation efficiency of the radiator 2 of the antenna, the signal coupled to the tuning point 7 can be transmitted to the conductor 8 through the cooperation of a flexible circuit board, a circuit board, and a spring. However, the circuit board and spring occupy a large volume, which cannot be utilized by the speaker 9, hindering the increase in the rear cavity of the speaker 9 and thus preventing the improvement of the speaker 9's sound effect.

[0170] To address the issue of large volume occupied by solutions connecting to the frame via circuit boards and spring contacts, refer to Figures 10, 11, and 12. Figure 10 shows the positional relationship of some structures within the CC region of Figure 7; Figure 11 is a cross-sectional view along the DD' direction in Figure 10; and Figure 12 is a cross-sectional view along the EE' direction in Figure 10. The foldable electronic device also includes a third flexible circuit board 24. Along the thickness direction of the electronic device, the third flexible circuit board 24 is located on one side of the functional device (such as the speaker 9), for example, between the speaker 9 and the second middle plate 522. One end of the third flexible circuit board 24 is directly connected to the conductor 8 (e.g., connected to the conductor 8 via the connection shown in Figure 11), and the other end of the third flexible circuit board 24 is grounded. For example, the second intermediate plate 522 is a metal intermediate plate, and the metal intermediate plate is connected to the grounding point of the printed circuit board (the third printed circuit board 17 or the fourth printed circuit board 18). In this way, the metal intermediate plate can serve as a reference ground, and the second end of the third flexible circuit board 24 can be directly connected to the metal intermediate plate (such as through the connection point in Figure 12) to achieve grounding. The embodiments of this application are all described using the metal intermediate plate as a reference ground as an example.

[0171] The foldable electronic device also includes a tuning circuit 26, which is disposed on and connected to the third flexible circuit board 24 and adjacent to the conductor 8. Furthermore, the tuning circuit 26 can be disposed between the speaker 9 and the third flexible circuit board 24. To prevent the tuning circuit 26 from affecting the speaker 9, a clearance groove is provided on the side of the speaker 9 facing the third flexible circuit board 24 to accommodate the tuning circuit 26. This arrangement, compared to placing a printed circuit board, a spring, and a tuning switch on the printed circuit board between the speaker 9 and the conductor 8, reduces the gap between the speaker 9 and the conductor 8 by 1.4 mm (including the 0.4 mm thickness of the printed circuit board, the 0.6 mm thickness of the tuning circuit 26, and the 0.4 mm clearance required between the tuning circuit 26 and the speaker 9). This allows the speaker 9 to expand outwards by 1.4 mm towards the conductor 8, increasing the volume of the speaker 9's rear cavity and improving its sound quality.

[0172] Referring to Figure 13, which shows the circuit diagram corresponding to the conductor, the structures of tuning circuit 26 and tuning circuit 25 can be the same. For example, tuning circuit 26 includes at least one control terminal Con2, one ground terminal Gnd2, and multiple tuning terminals. Multiple tuning links are provided within tuning circuit 26, with one end of each link connected to a corresponding tuning terminal. The other end of each link is connected to the ground terminal Gnd2. Conductor 8 is connected to multiple tuning terminals e2 of tuning circuit 26 via the third flexible circuit board 24. The ground terminal Gnd2 of tuning circuit 26 is connected to the metal middle plate via the third flexible circuit board 24 for grounding. The control terminal Con2 of the second tuning circuit 26 is connected to different links, and tuning circuit 26 conducts different tuning links based on different control signals received by its control terminal Con2. The resonant frequency band of conductor 8 is tuned through the conducted tuning links, making the resonant frequency of the signal on conductor 8 different from that on the radiator 2 of the antenna. Different tuning links correspond to different resonant frequency bands. In this way, conductor 8 can serve as a parasitic branch of the radiator 2 of the antenna, radiating the energy coupled from the feed 3 and improving the radiation efficiency of the radiator 2 of the antenna.

[0173] For example, the tuning circuit 26 has three tuning terminals: a fourth tuning terminal e21, a fifth tuning terminal e22, and a sixth tuning terminal e23. Correspondingly, multiple tuning links include a fourth tuning link, a fifth tuning link, and a sixth tuning link. The fourth tuning link includes a fourth switch 261 and a fourth matching device 264; the fifth tuning link includes a fifth switch 262 and a fifth matching device 265; and the sixth tuning link includes a sixth switch 263 and a sixth matching device 266. The fourth matching device 264 is connected to one end of the fourth tuning terminal e21 and the fourth switch 261, respectively; the fifth matching device 265 is connected to one end of the fifth tuning terminal e22 and the fifth switch 262, respectively; and the sixth matching device 266 is connected to one end of the sixth tuning terminal e23 and the sixth switch 263, respectively. The other ends of the fourth switch 261, the fifth switch 262, and the sixth switch 263 are all connected to the ground terminal Gnd2. Conductor 8 is connected to the fourth tuning terminal e21, the fifth tuning terminal e22, and the sixth tuning terminal e23 of the tuning circuit 26 via the third flexible circuit board 24. The ground terminal Gnd2 of the tuning circuit 26 is grounded by connecting to the metal middle plate via the third flexible circuit board 24. The control terminal Con2 of the tuning circuit 26 receives control signals including the fourth control signal, the fifth control signal, and the sixth control signal.

[0174] When the control signal received by the control terminal Con1 of the resonant circuit 25 is the first control signal, the first tuning link in the resonant circuit 25 is turned on and grounded. The first tuning link in the resonant circuit 25 tunes the resonant frequency band of the radiator 2 of the antenna, such as tuning to the first resonant frequency band. At the same time, the control terminal Con2 of the tuning circuit 26 receives the fourth control signal, the fourth switch 261 in the tuning circuit 26 is turned on, and the fourth matching device 264 is grounded. The fourth matching device 264 in the tuning circuit 26 tunes the resonant frequency band of the conductor 8, so that the resonant frequency of the signal on the conductor 8 is different from that of the signal on the radiator 2 of the antenna. In this way, the conductor 8 can act as a parasitic branch of the radiator 2 of the antenna, radiating the energy coupled from the feed 3 and improving the radiation efficiency of the radiator 2 of the antenna.

[0175] When the control signal received by the control terminal Con1 of the resonant circuit 25 is the second control signal, the second tuning link in the resonant circuit 25 is turned on and grounded. The second tuning link in the resonant circuit 25 tunes the resonant frequency band of the radiator 2 of the antenna, such as tuning to the second resonant frequency band. At the same time, the control terminal Con2 of the tuning circuit 26 receives the fifth control signal, the fifth switch 262 in the tuning circuit 26 is turned on, and the fifth matching device 265 is grounded. The fifth matching device 265 in the tuning circuit 26 tunes the resonant frequency band of the conductor 8, so that the resonant frequency of the signal on the conductor 8 is different from that of the signal on the radiator 2 of the antenna. In this way, the conductor 8 can act as a parasitic branch of the radiator 2 of the antenna, radiating the energy coupled from the feed 3 and improving the radiation efficiency of the radiator 2 of the antenna.

[0176] When the control signal received by the control terminal Con1 of the resonant circuit 25 is the third control signal, the third tuning link in the resonant circuit 25 is turned on and grounded. The third tuning link in the resonant circuit 25 tunes the resonant frequency band of the radiator 2 of the antenna, such as tuning to the third resonant frequency band. At the same time, the control terminal Con2 of the tuning circuit 26 receives the sixth control signal, the sixth switch 263 in the tuning circuit 26 is turned on, and the sixth matching device 266 is grounded. The sixth matching device 266 in the tuning circuit 26 tunes the resonant frequency band of the conductor 8, so that the signal of the conductor 8 is different from the resonant frequency of the signal on the radiator 2 of the antenna. In this way, the conductor 8 can act as a parasitic branch of the radiator 2 of the antenna, radiating the energy coupled from the feed 3 and improving the radiation efficiency of the radiator 2 of the antenna.

[0177] The control signal received by the control terminal Con2 of the tuning circuit 26 can be provided by a processor located on the first printed circuit board 15. That is, the processor outputs a control signal, which is transmitted to the control terminal Con2 of the resonant circuit 26 through the first printed circuit board 15, the through-axis flexible circuit board, the third printed circuit board 17, the second flexible circuit board 22, the fourth printed circuit board 18, and the third flexible circuit board 24. Of course, this does not constitute a limitation of this application, and it can also be provided by other devices with control functions (such as the radio frequency integrated circuit 232) in the foldable electronic device.

[0178] It should be noted that the above example uses an antenna system 1 including one antenna, and a through-slit is provided on the first frame 421 to obtain an independent metal frame used as the radiator 2 of the antenna; correspondingly, a through-slit is also provided on the metal frame of the second frame 5 to form a conductor 8, which overlaps with the radiator 2 of the first frame 4 when the foldable phone is in the folded state. However, this does not constitute a limitation of this application. In an optional embodiment of this application, referring to FIG14, FIG14 is another relationship diagram of the positions of some functional components inside the electronic device shown in FIG5. The antenna system 1 may also include multiple antennas, such as three antennas, including a first antenna, a second antenna, and a third antenna. In addition to slits a and b, the first frame 421 also has slits e and f. Slits a, b, e, and f separate the first frame 421 into three independent metal frames, which serve as the radiators of the three antennas. For example, slits a and b separate the first frame 421 into three independent metal frames. 421 separates a separate metal frame (also called the first stub), which serves as the radiator 2 of the first antenna; slots a and e separate the first frame 421 into another separate metal frame (also called the third stub), which serves as the radiator 2a of the second antenna, and correspondingly, the radiator 2a of the second antenna also has a corresponding feed; slots f and e separate the first frame 421 into yet another separate metal frame (also called the fifth stub), which serves as the radiator 2b of the third antenna, and correspondingly, the radiator 2b of the third antenna also has a corresponding feed. Accordingly, the second frame 521 of the second frame 5, in addition to slots c and d, also has slots g and h. Slits c, d, g, and h allow the second frame 5 to form not only conductor 8 (also called the second branch), but also conductor 8a (also called the fourth branch) and conductor 8b (also called the sixth branch). When the foldable phone is in the folded state, conductor 8 overlaps with the radiator 2 of the first frame 4. When the foldable phone is in the folded state, conductor 8a overlaps with the radiator 2a of the first frame 4. When the foldable phone is in the folded state, conductor 8b overlaps with the radiator 2b of the first frame 4.

[0179] In this case, to avoid transmitting the signal coupled from the feed source to conductors 8a and 8b through the cooperation of the flexible circuit board, the circuit board and the spring, see Figure 15. Figure 15 is a diagram showing the positional relationship between the third flexible circuit board and each conductor provided in the embodiment of this application. The third flexible circuit board 24 is also directly connected to conductors 8a and / or conductors 8b.

[0180] It is understandable that, in order to cover a wider bandwidth, the second and / or third antennas will also be equipped with resonant circuits. The tuning principle of the resonant circuits corresponding to the second and / or third antennas is similar to that of tuning circuit 25 described above, as detailed above. Correspondingly, conductors 8a and / or 8b will also be equipped with resonant circuits 26. The resonant circuit corresponding to conductor 8a modulates the signal on conductor 8a, making the resonant frequency of the signal on conductor 8a different from that of the signal on the radiator 2a of the antenna. Similarly, the resonant circuit corresponding to conductor 8b modulates the signal on conductor 8b, making the resonant frequency of the signal on conductor 8b different from that of the signal on the radiator 2b of the antenna. The tuning principle of the resonant circuits corresponding to conductors 8a and / or 8b is similar to that of tuning circuit 26 described above, as detailed above. Figure 15 illustrates this using the example of a third flexible circuit board 24 directly connected to conductor 8b, a third antenna equipped with a resonant circuit, and conductor 8b also equipped with resonant circuit 26.

[0181] It should also be noted that the above examples illustrate how the arrangement of the third flexible circuit board 24 can resolve the layout conflict between the tuning point and the speaker, and how the circuit board and spring occupy a large volume. However, this does not constitute a limitation of this application; this solution can be adopted whenever other functional architectures within the device conflict with the location of the tuning point and / or the feed source.

[0182] For example, this solution can also be used when the placement of the feed 3 and / or the placement of some structures for grounding the radiator 2 of the antenna conflict with the placement of other components in the first receiving cavity. Continuing with Figure 14 as an example, when the placement of the feed 3 corresponding to the first antenna (i.e., radiator 2) and the feed 3 corresponding to the second antenna (i.e., radiator 2a) (not shown in the figure) conflict with the placement of other components in the first receiving cavity, a third flexible circuit board 24 can also be placed in the first receiving cavity. Referring to Figure 16, which is a positional relationship diagram between the third flexible circuit board and the radiator corresponding to the first antenna and the radiator corresponding to the second antenna provided in this embodiment, the third flexible circuit board 24 has the aforementioned resonant circuit 25 placed near the radiator 2 of the first antenna, and another resonant circuit 25a placed near the radiator 2a of the second antenna. The radiator 2 of the first antenna is connected to multiple tuning terminals of its corresponding resonant circuit 25 via a third flexible circuit board 24. The ground terminal Gnd1 of the resonant circuit 25 is directly connected to the first intermediate board 422 via the third flexible circuit board 24 to achieve grounding. The control terminal Con1 of the resonant circuit 25 receives different control signals sent by the processor (not shown in the figure) on the first printed circuit board 15 via the third flexible circuit board 24 (the control signal transmission path is shown by the thick dashed line in Figure 16). The resonant circuit 25 conducts different tuning links based on the different control signals received by its control terminal Con1. The resonant frequency band of the radiator 2 of the antenna is tuned through the conducted tuning links. The radiator 2a of the second antenna is connected to multiple tuning terminals of its corresponding resonant circuit 25a via the third flexible circuit board 24. The ground terminal of the resonant circuit 25a is directly connected to the first intermediate board 422 via the third flexible circuit board 24 to achieve grounding. The control terminal of the resonant circuit 25a receives different control signals sent by the processor on the first printed circuit board 15 via the third flexible circuit board 24. The resonant circuit 25a conducts different tuning links based on the different control signals received by its control terminal Con1. The resonant frequency band of the radiator 2a of the antenna is tuned through a conducting tuning link. Furthermore, the third flexible circuit board 24 is connected to the RF front-end module (not shown in Figure 16) located on the first printed circuit board 15 via the first printed circuit board 15. The third flexible circuit board 24 is also used to transmit signals to the radiator 2 of the first antenna and the radiator 2a of the second antenna in a transmitting scenario, so that the signals are converted into electromagnetic waves for radiation by the radiator 2 of the first antenna and the radiator 2a of the second antenna; or, in a receiving scenario, to receive electromagnetic waves acquired from the radiator 2 of the first antenna and the radiator 2a of the second antenna, and convert the electromagnetic waves into electrical signals. The third flexible circuit board 24 is also used to transmit the electrical signals converted by the radiator 2 of the first antenna and the radiator 2a of the second antenna to the RF front-end module (the signal transmission path is shown by the thick solid line in Figure 16).

[0183] For example, referring to Figure 17, which is a cross-sectional view of the electronic device shown in Figure 5 along the FF' direction, the second outer shell 51 can be a display screen for a foldable mobile phone (to distinguish it from the flexible display screen 14, the display screen here can be called the outer screen, and the flexible display screen 14 can be called the inner screen). The conductor 8 and the end 511 of the outer screen are spaced apart, such as a distance greater than or equal to 0 mm and less than or equal to 0.4 mm. The second surface M2 of the second middle plate 522 is provided with a protrusion 5221. The speaker 9 is disposed on the second middle plate 522, and the speaker 9 is limited by the protrusion 5221. The third flexible circuit board 24 is disposed between the inner screen and the outer screen, and one end of the third flexible circuit board 24 is connected to the side wall of the conductor 8, and the other end of the third flexible circuit board 24 is disposed on the protrusion 5221 of the second middle plate 522 to achieve grounding. The tuning circuit 26 is disposed on the third flexible circuit board 24, and is located between the speaker 9 and the third flexible circuit board 24 along the thickness direction of the electronic device. The tuning circuit 26 is connected to the third flexible circuit board 24 and is disposed adjacent to the conductor 8. In this way, the screen device (such as the display driver chip that drives the outer screen) disposed at the end 511 of the outer screen needs to be bent to the back of the outer screen to connect with the printed circuit board (such as the fourth printed circuit board 18), occupying space in the thickness direction. However, this also allows for a smaller thickness of the foldable phone in the unfolded state (i.e., the distance between the inner and outer screens) (e.g., the minimum distance H1 between the inner and outer screens is less than 2mm). In other words, compared to using a circuit board (typically about 0.456mm thick) and a spring clip to transmit the coupled signal to the conductor 8 near the end 511 of the outer screen, the thickness of the foldable phone can be greatly reduced. It should be noted that this example is based on the premise that the minimum distance H1 between the inner and outer screens is less than 2mm, but it does not constitute a limitation of this application. In other optional embodiments of this application, the minimum distance H1 between the inner and outer screens can also be greater than or equal to 2mm. Using this approach, the antenna clearance area can be larger.

[0184] It should also be noted that the above example is based on the scenario where the third flexible circuit board 24 is located between the second intermediate plate 522 and the functional device (such as the speaker 9), and the tuning circuit 26 located on the third flexible circuit board 24 is located between the third flexible circuit board 24 and the functional device. However, this does not constitute a limitation of this application, and the position of the third flexible circuit board 24 can be adaptively adjusted according to the actual situation (such as the specific placement position of the functional device). For example, referring to Figure 18, Figure 18 is a positional relationship diagram of the third flexible circuit board, the functional device, and the tuning circuit provided in an embodiment of this application. The second surface M2 of the second intermediate plate 522 is provided with a protrusion 5221 (a protrusion provided for limiting and / or fixing some functional devices in the electronic device). One end of the third flexible circuit board 24 is connected to the sidewall of the conductor 8, and the other end of the third flexible circuit board 24 is provided on the protrusion 5221 of the second intermediate plate 522 to achieve grounding. The third flexible circuit board 24 can also be located on the side of the functional device (such as the speaker 9) away from the second intermediate plate 522, and the tuning circuit 26 on the third flexible circuit board 24 is located between the third flexible circuit board 24 and the functional device. In addition, the third flexible circuit board 24 can not only be arranged adjacent to the second housing 51 (see FIG19, which is another positional relationship diagram of the third flexible circuit board, functional device and tuning circuit provided in the embodiment of this application), but the third flexible circuit board 24 can also be arranged adjacent to the flexible display screen 14. Furthermore, the third flexible circuit board 24 can also be located on the side of a functional device (such as a speaker 9), as shown in Figures 20 and 21. Figure 20 is another positional relationship diagram of the third flexible circuit board, functional device, and tuning circuit provided in the embodiment of this application, and Figure 21 is another positional relationship diagram of the third flexible circuit board, functional device, and tuning circuit provided in the embodiment of this application. The difference between Figures 20 and 21 is that, in Figure 20, the end of the third flexible circuit board 24 connected to the side wall of the conductor 8 is not located between the side wall of the conductor 8 and the side wall of the functional device; in Figure 21, the end of the third flexible circuit board 24 connected to the side wall of the conductor 8 is located between the side wall of the conductor 8 and the side wall of the functional device. It is understandable that when the third flexible circuit board 24 can also be located on the side of the functional device, the third flexible circuit board 24 is generally perpendicular to the plane where the second middle plate 522 is located. In order to achieve grounding between the third flexible circuit board 24 and the second middle plate 522, the third flexible circuit board 24 also includes a straight part 24a parallel to the plane where the second middle plate 522 is located, which is used to connect with the second middle plate 522 to achieve grounding.

[0185] It should also be noted that the above examples are all illustrated by using the third flexible circuit board 24 and the tuning circuits (such as tuning circuit 25 and / or tuning circuit 26) on the third flexible circuit board to achieve the tuning between the metal frame and the metal middle plate (i.e., ground), but this does not constitute a limitation of this application.

[0186] In some embodiments, when tuning is required between metal frames (i.e., by providing through-holes in the first frame 421 or the second frame 521, thereby obtaining at least two independent metal frames), a third flexible circuit board 24 and a tuning circuit can also be provided between the at least two independent metal frames. For example, referring to FIG22, which is a positional relationship diagram between the third flexible circuit board and the metal frames provided in an embodiment of this application, at least two independent metal frames can be obtained by providing at least one through-hole i in the first frame 421. For instance, by providing one through-hole i in the first frame 421, two independent metal frames, namely metal frame 2c and metal frame 2d, are obtained. A third flexible circuit board 24 is provided between metal frame 2c and metal frame 2d, i.e., the third flexible circuit board 24 connects metal frame 2c and metal frame 2d respectively. A tuning circuit 27 is provided on the third flexible circuit board 24. For example, antenna system 1 also includes a fourth antenna. Metal frames 2c and 2d serve as the radiators of the fourth antenna. Tuning circuit 27 tunes the radiators of the fourth antenna (the tuning principle is similar to that of tuning circuit 25, as detailed above, and will not be repeated here), allowing the fourth antenna to cover a wider bandwidth. Continuing with Figure 22, the third flexible circuit board 24 can also be grounded to achieve tuning between the radiators of the fourth antenna and ground.

[0187] In summary, directly connecting the third flexible circuit board to the frame resolves the conflict between antenna placement and other functional architectures in the electronic device. It also saves on spring contacts and circuit boards, freeing up more space for other structures and / or facilitating miniaturization and thinner design. Furthermore, saving on spring contacts reduces one transition, thus avoiding increased system impedance due to transitions. Since the required signal reaches the antenna directly, impedance discontinuities in the signal path to the antenna caused by uncontrollable spring contact impedance are optimized. Moreover, placing the tuning circuit on the third flexible circuit board allows the radiator 2 to cover a wider bandwidth without requiring a separate structure to carry the tuning circuit, simplifying the electronic device's structure.

[0188] This application does not limit the manner in which the third flexible circuit board 24 is connected to the conductor 8, the manner in which the third flexible circuit board 24 is connected to the radiator, and / or the manner in which the third flexible circuit board 24 is connected to the metal middle plate.

[0189] The third flexible circuit board 24 can be connected to the conductor 8 in a way that includes flexible direct connection, rigid direct connection, coupling connection or conversion, etc.; the third flexible circuit board 24 can be connected to the radiator in a way that includes flexible direct connection, rigid direct connection, coupling connection or conversion, etc.; the third flexible circuit board 24 can be connected to the metal middle plate in a way that includes flexible direct connection, rigid direct connection, coupling connection or conversion, etc. Among them, flexible direct connection refers to the method of achieving current conduction by directly connecting with flexible materials such as conductive adhesive or silver paste; rigid direct connection refers to the method of achieving current conduction by directly connecting through a molten pool (such as laser welding, ultrasonic welding, etc.) or rigid interference (such as riveting, etc.); coupling connection refers to the coupling caused by the large-area overlap between the end of the third flexible circuit board 24 and the conductor 8 and / or the metal middle plate. For example, the end of the third flexible circuit board 24 can be attached to the conductor 8 and / or the metal middle plate by using a non-conductive adhesive with a high dielectric constant. In this way, the part of the third flexible circuit board 24 attached to the conductor 8 is opposite to the conductor 8, thereby generating capacitive coupling. Also, the part of the third flexible circuit board 24 attached to the metal middle plate is opposite to the metal middle plate, thereby generating capacitive coupling; transition refers to connecting the end of the third flexible circuit board 24 to the connecting medium, and then the connector is connected to the conductor 8 and / or the metal middle plate through flexible direct connection, rigid direct connection, or coupling connection. For example, referring to Figure 23, which is a positional relationship diagram of the third flexible circuit board, connector, and conductor provided in an embodiment of this application, the connector 40 includes a first connecting sub-component 41 and a second connecting sub-component 42 that are connected to each other. The plane where the first connecting sub-component 41 is located and the plane where the second connecting sub-component 42 is located have a preset angle (which can be any angle from 60° to 120°, such as 60°, 70°, 80°, 90°, 100°, 110°, or 120°). The first connecting sub-component 41 is connected to the third flexible circuit board 24, and the second connecting sub-component 42 is connected to the conductor 8 by a flexible direct connection, a rigid direct connection, or a coupling connection. The end of the third flexible circuit board 24 is connected to the conductor 8 and / or the metal middle plate by an adapter. This is generally because some positions cannot be directly connected to the conductor 8 and / or the metal middle plate by flexible direct connection, rigid direct connection, or coupling connection due to space limitations or process limitations (such as the flexible circuit board being too weak to be attached to the conductor 8).

[0190] In some embodiments, a stress-relieving structure is provided on the third flexible circuit board 24. This stress-relieving structure can release the stress generated when the third flexible circuit board 24 deforms, preventing the third flexible circuit board 24 from deforming and breaking the circuit when the electronic device is subjected to large forces such as impacts, thus improving the reliability of the antenna connection structure. The stress-relieving structure can be at least one hollow portion 241 provided on the third flexible circuit board 24 (as shown in Figure 24a), where the hollow portion is a hole penetrating the third flexible circuit board 24 along its thickness direction; it can also be a redundant portion 242 provided in the third flexible circuit board 24 (as shown in Figure 24b), where the redundant portion is the portion remaining after subtracting the distance between the two ends of the third flexible circuit board 24 from its actual length. This remaining portion can release the tensile force on the third flexible circuit board 24 to a certain extent, thereby preventing the third flexible circuit board 24 from being torn; or, the redundant portion can be a wrinkled (i.e., bent) portion of the third flexible circuit board 24 other than the straight portion.

[0191] In some embodiments, referring to FIG25, FIG25 is a connection diagram of a third flexible circuit board and various functional devices provided in an embodiment of the present application. The third flexible circuit board 24 is also connected to at least one functional device. For example, the third flexible circuit board 24 is also connected to the SIM card interface 90 and the speaker 9. In this way, the third flexible circuit board 24 can not only transmit control signals to the control terminal Con2 of the tuning circuit 26 located on the third flexible circuit board 24, but also provide corresponding signals to the speaker 9 and the SIM card interface 90 so that the speaker 9 and the SIM card interface 90 can perform their respective functions. In this way, it is not necessary to set up a structure for receiving corresponding signals for functional devices such as the SIM card interface 90 and the speaker 9, simplifying the structure of the electronic device and facilitating the thinner and lighter design of the electronic device.

[0192] It should be noted that the above description is based on the example of the first frame 421 having gaps a and b near the second printed circuit board 16, with gaps a and b separating the first frame 421 into an independent metal frame, which serves as the radiator 2 of the antenna. However, this does not constitute a limitation of this application. In some optional embodiments, referring to FIG26, which is another relationship diagram of the positions of some functional components inside the electronic device shown in FIG5, the first frame 421 may also have gaps a and b near the side of the first battery 19, with gaps a and b separating the first frame 421 into an independent metal frame, which serves as the radiator 2 of the antenna. That is, the radiator 2 of the antenna is spaced apart from the first battery 19, and the distance between the radiator 2 of the antenna and the first battery 19 is, for example, greater than or equal to 1 mm and less than or equal to 2 mm. Correspondingly, the second frame 521 also separates an independent metal frame through gaps c and d, forming a conductor 8. When the foldable phone is in the folded state, the conductor 8 overlaps with the radiator 2 separated by gaps a and b. The conductor 8 is spaced apart from the second battery 20, with the distance between the conductor 8 and the second battery 20 being, for example, greater than or equal to 1 mm and less than or equal to 2 mm.

[0193] In this configuration, the third flexible circuit board 24 can be positioned between the antenna radiator 2 and the first flexible circuit board 21. For example, one end of the third flexible circuit board 24 is directly connected to the antenna radiator 2, and the other end is directly connected to the first intermediate plate 422 (i.e., the first intermediate plate 422 is a metal intermediate plate) for grounding (not shown in the figure). The other end of the third flexible circuit board 24 is connected to the first flexible circuit board 21. The resonant circuit 25 is mounted on and connected to the third flexible circuit board 24, and is positioned adjacent to the antenna radiator 2. The antenna radiator 2 is connected to multiple tuning terminals of the resonant circuit 25 via the third flexible circuit board 24. The grounding terminal Gnd1 of the resonant circuit 25 is grounded via the third flexible circuit board 24. The control terminal Con1 of the resonant circuit 25 receives different control signals, and the resonant circuit 25 conducts different tuning links based on the different control signals received by its control terminal Con1. The resonant frequency band of the antenna radiator 2 is tuned through the conducted tuning links, where different tuning links correspond to different resonant frequency bands. In this way, the bandwidth of the radiator 2 of the antenna can cover a wider bandwidth. The control signal can be provided by a processor located on the first printed circuit board 15; that is, the processor outputs a control signal, which is transmitted through the first printed circuit board 15, the first flexible circuit board 21, and the third flexible circuit board 24 to the control terminal Con1 of the resonant circuit 25. And / or,

[0194] The third flexible circuit board 24 can be disposed between the conductor 8 and the second flexible circuit board 22. For example, one end of the third flexible circuit board 24 is connected to the conductor 8, and the other end is connected to the second intermediate plate 522 (i.e., the second intermediate plate 522 is a metal intermediate plate) for grounding (not shown in the figure). Another end of the third flexible circuit board 24 is connected to the second flexible circuit board 22. The resonant circuit 26 is disposed on and connected to the third flexible circuit board 24. The conductor 8 is connected to multiple tuning terminals of the resonant circuit 26 through the third flexible circuit board 24. The grounding terminal Gnd1 of the resonant circuit 26 is grounded through the third flexible circuit board 24. The control terminal Con1 of the resonant circuit 26 is used to receive different control signals. The resonant circuit 26 conducts different tuning links based on the different control signals received by its control terminal Con1. The resonant frequency band of the conductor 8 is tuned through the conducted tuning links, where different tuning links correspond to different resonant frequency bands, making the resonant frequency of the signal on the conductor 8 different from that of the signal on the radiator 2 of the antenna. The control signal can be provided by a processor located on the first printed circuit board 15, that is, the processor outputs a control signal, which is transmitted to the control terminal Con2 of the resonant circuit 26 through the first printed circuit board 15, the flexible circuit board of the rotating shaft, the third printed circuit board 17, the second flexible circuit board 22, and the third flexible circuit board 24.

[0195] By directly connecting the third flexible circuit board to the frame located on the side of the battery, the need for spring clips and circuit boards and other connecting structures can be eliminated, leaving more space for the battery. This solves the problem that the distance between the battery compartment and the side frame is too small to accommodate spring clips and circuit boards, thus preventing the battery side frame from being used as an antenna. Alternatively, it solves the problem that the small distance between the battery compartment and the side frame, due to the large volume occupied by spring clips and circuit boards and other connecting structures, occupies the battery's placement space and thus affects the battery capacity.

[0196] The first flexible circuit board 21 and the third flexible circuit board 24 can be integrally formed. That is, the first flexible circuit board 21 can not only connect the first printed circuit board 15 and the second printed circuit board 16, but also connect the radiator 2 of the antenna and provide control signals for the resonant circuit 25.

[0197] Considering that the side of the first battery 20 facing away from the first intermediate plate 422 may have not only the first flexible circuit board 21, but also other flexible circuit boards, when multiple flexible circuit boards overlap in the thickness direction, it will have a significant impact on the wireless communication signal (including the feed signal transmitted to the radiator 2 of the antenna, and / or the electrical signal converted from the electromagnetic waves received by the radiator 2 of the antenna), and affect the size of the first battery 20 in the thickness direction, thereby affecting the battery capacity of the first battery 20. Based on this, the foldable electronic device also includes a coaxial transmission line 28. One end of the coaxial transmission line 28 is connected to the radio frequency front-end module 231 through the first printed circuit board 15, and the other end is connected to the radiator 2 of the antenna. The coaxial transmission line 28 is used to transmit wireless communication signals. Specifically, in the transmission scenario, the baseband processor 233 synthesizes the data (digital signal) to be transmitted into a baseband signal to be transmitted, and modulates the baseband signal into a baseband modulated signal and sends it to the radio frequency integrated circuit 232. The radio frequency integrated circuit 232 converts the baseband modulated signal into a transmission signal. After the transmission signal is mixed, amplified, filtered and processed by the radio frequency front-end module 231, it is transmitted to the radiator 2 of the antenna through the coaxial transmission line 28. The radiator 2 of the antenna converts the transmission signal into electromagnetic waves for radiation.

[0198] For example, in a receiving scenario, the radiator 2 of the antenna can receive electromagnetic waves and convert them into electrical signals, which are then transmitted to the coaxial transmission line 28. The signals are then transmitted to the radio frequency front-end module 231 on the first printed circuit board 15 via the coaxial transmission line 28. In the radio frequency front-end module 231, a device with a switching function switches to the corresponding receiving link. The receiving link amplifies, filters, mixes, and processes the signal before sending it to the radio frequency integrated circuit 232. The radio frequency integrated circuit 232 processes the signal into a baseband modulated signal and transmits it to the baseband processor 233. The baseband processor 233 converts the baseband modulated signal into a baseband signal and then converts the baseband signal into data to determine the information carried in the electromagnetic wave.

[0199] By transmitting wireless communication signals and control signals separately (control signals are transmitted from the first flexible circuit board 21, and wireless communication signals are transmitted from the coaxial transmission line 28), the insertion loss is minimized.

[0200] Considering that printed circuit boards (PCBs) are relatively thick and the components on them occupy space in the thickness direction of foldable electronic devices, it is not conducive to the thinner and lighter design of electronic devices. Based on this, all PCBs in foldable phones can be replaced with flexible circuit boards (to distinguish them from the aforementioned flexible circuit boards, the flexible circuit board here can be referred to as the fourth flexible circuit board). Specifically, referring to Figure 27, which is a top view of the positional relationship of the fourth flexible circuit board, the antenna radiator, the frame, and the middle plate provided in this application, the foldable electronic device also includes a fourth flexible circuit board 29, disposed in the first and second receiving cavities. That is, the first PCB 15, the second PCB 16, the first flexible circuit board 21 in the first receiving cavity, and the third PCB 17, the fourth PCB 18, the second flexible circuit board 22, and the through-axis flexible circuit board in the second receiving cavity are all replaced by the fourth flexible circuit board 29. The fourth flexible circuit board 30 is equipped with components such as an RF front-end module 231, an RF integrated circuit 232, a baseband processor 233, and a processor, and / or functional devices (such as a speaker 9, a SIM card interface 90, etc.) connected to the fourth flexible circuit board 30. The fourth flexible circuit board 29 can also be reused as a third flexible circuit board 24 (using a metal frame as the radiator of the antenna), and connected to the metal middle plate and the metal frame.

[0201] For example, continuing to refer to Figure 27, the fourth flexible circuit board 29 includes a central portion 291, at least one first branch portion 292, and at least one second branch portion 293. The first branch portion 292 is connected to the central portion 291, and the second branch portion 293 can be connected to either the central portion 291 or the first branch portion 292; this embodiment does not limit the connection. The radio frequency front-end module 231, radio frequency integrated circuit 232, baseband processor 233, processor, etc., are disposed on the central portion 291. At least one first branch portion 292 is connected to at least one functional device, and at least one second branch portion 293 is connected to a metal middle plate and a metal frame (as shown in the specific connection method of Figure 10) to realize the antenna function.

[0202] It should be noted that the number of the first branch portions 292 can correspond to the number of functional devices, and the number of the first branch portions 292 can be set according to the number of functional devices; the number of the second branch portions 293 can correspond to the number of radiators, etc., and the number of the second branch portions 293 can be set according to the number of radiators, etc.

[0203] It should also be noted that the first branch 292, the second branch 293, and the central part 291 can be integrally formed or formed separately. For example, in some scenarios, due to overlapping or uneven unfolding of the various branch parts, each branch part can be processed separately from the central part according to requirements, and then connected to the central part 291 by welding technology such as FPC on Board (FOB) that combines flexible and rigid boards; or by flexible connection structures such as conductive silver paste; or by conventional connection structures such as spring sheets or BTB.

[0204] It should also be noted that the thickness of the fourth flexible circuit board 29 is not limited in this embodiment of the application, as long as it can meet the required strength.

[0205] The radio frequency front-end module 231, radio frequency integrated circuit 232, baseband processor 233, processor, etc. are all placed on the fourth flexible circuit board 29, eliminating the need for a printed circuit board, which is beneficial for the thinner and lighter design of electronic devices.

[0206] It should be noted that the following description is based on the example that the first printed circuit board 15, the second printed circuit board 16, and the first flexible circuit board 21 in the first receiving cavity, as well as the third printed circuit board 17, the fourth printed circuit board 18, and the second flexible circuit board 22 in the second receiving cavity, and the through-shaft flexible circuit board are all replaced by the fourth flexible circuit board 29.

[0207] The above examples all use conductive structural materials, such as metal materials (i.e., the materials of the first frame 4 and the second frame 5 are metallic materials), as examples for illustration. However, this does not constitute a limitation of this application. In other optional embodiments of this application, the materials of the first frame 4 and the second frame 5 can also be non-conductive structural materials. For example, the materials of the first frame 421, the second frame 521, the first middle plate 422, and the second middle plate 522 can include non-metallic materials such as plastic, glass, and ceramic; or, the materials of the first frame 421 and the second frame 521 are non-metallic materials, and the materials of the first middle plate 422 and the second middle plate 522 are metallic materials.

[0208] In this situation (when the materials of the first frame 4 and the second frame 5 are non-conductive structural materials), to achieve the antenna's radiation function, one possible implementation is shown in Figures 28 and 29. Figure 28 is a top view showing another positional relationship between the fourth flexible circuit board, the antenna radiator, the frame, and the middle plate provided in this application. Figure 29 is a cross-sectional view of the electronic device shown in Figure 28 along the FF' direction. The area of ​​the fourth flexible circuit board connected to the frame is reused as the antenna radiator. The portion of the fourth flexible circuit board reused as the antenna radiator can be integrally formed with other parts of the fourth flexible circuit board 29, or it can be discontinuously processed and then reconnected as needed.

[0209] In another possible implementation, referring to Figures 30 and 31, Figure 30 is a top view showing another possible positional relationship between the fourth flexible circuit board, the radiator of the antenna, the frame, and the middle plate provided in this application. Figure 31 is a cross-sectional view of the electronic device shown in Figure 30 along the GG' direction. A conductive structure 30 is provided on the side wall of the frame, such as silver paste, steel sheet, modified plastic containing organometallic composites (Laser Direct Structuring, LDS), plastic mold steel (PDS), etc. The fourth flexible circuit board 29 is connected to the conductive structure 30, which is the radiator of the antenna. The connection method between the fourth flexible circuit board 29 and the conductive structure 30 includes, but is not limited to, conductive adhesive, silver paste, soldering, etc.

[0210] Regardless of whether the materials of the first frame 4 and the second frame 5 mentioned above are conductive or non-conductive structural materials, they are all rigid structural materials. However, this does not constitute a limitation of this application. In other optional embodiments of this application, the material of the frame can also be flexible materials such as polyimide (PI) and polyethylene terephthalate (PET) (i.e., the frame is a flexible frame). Combined with a flexible circuit board and a flexible display screen, a flexible electronic device can be formed. For example, see Figure 32. Figure 32 is a schematic diagram of the structure of another electronic device provided by an embodiment of this application. In Figure 32, a flexible wearable electronic device, such as a flexible wearable electronic device with a smart wristband-like link function, can be formed.

[0211] Any content in the various embodiments of this application, as well as any content in the same embodiment, can be freely combined. Any combination of the above content is within the scope of this application.

[0212] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An electronic device, characterized in that, The electronic device is a foldable electronic device, and the foldable electronic device includes: A first frame, at least a portion of which forms a first branch, the first branch being a radiator of the first antenna; the first antenna is used to operate in at least two operating frequency bands; A second frame, at least a portion of which forms a second branch, wherein when the electronic device is in a folded state, the projection of the second branch along the thickness direction of the electronic device at least partially coincides with the projection of the first branch along the thickness direction of the electronic device; A flexible circuit board, the flexible circuit board being connected to the second branch, and the flexible circuit board being grounded; A first tuning circuit is disposed on the flexible circuit board and electrically connected to the flexible circuit board. The first tuning circuit includes multiple first tuning links, and the first tuning circuit is used to enable the second stub to operate in at least two operating frequency bands; the operating frequency band of the first antenna is different from the operating frequency band of the second stub.

2. The electronic device according to claim 1, characterized in that, The first tuning circuit includes a control terminal, which is used to receive different control signals and to activate different first tuning links based on the different control signals. When one of the multiple first tuning links is turned on, the second stub operates in at least one of the at least two operating frequency bands corresponding to the second stub.

3. The electronic device according to claim 1 or 2, characterized in that, The foldable electronic device further includes a second tuning circuit connected to the first stub; the second tuning circuit includes multiple second tuning links, and the second tuning circuit is used to enable the first stub to operate in at least two operating frequency bands. When one of the multiple second tuning links is turned on, the first stub operates in at least one of the at least two operating frequency bands corresponding to the first stub.

4. The electronic device according to any one of claims 1-3, characterized in that, At least a portion of the first frame further forms a third branch, which is a radiator of the second antenna; the second antenna is used to operate in at least two operating frequency bands; At least a portion of the second frame also forms a fourth branch, the projection of the fourth branch along the thickness direction of the electronic device when the electronic device is in a folded state at least partially coinciding with the projection of the third branch along the thickness direction of the electronic device; The flexible circuit board is also connected to the fourth branch; The electronic device further includes a third tuning circuit, which is disposed on the flexible circuit board and electrically connected to the flexible circuit board; The third tuning circuit includes multiple third tuning links, and the third tuning circuit is used to enable the fourth stub to operate in at least two operating frequency bands; the operating frequency band of the second antenna is different from the operating frequency band of the fourth stub.

5. The electronic device according to any one of claims 1-4, characterized in that, The foldable electronic device further includes a first functional component, the second branch and the first functional component are spaced apart, and the flexible circuit board is located on one side of the first functional component along the thickness direction of the electronic device.

6. The electronic device according to claim 5, characterized in that, The first functional device is a battery, a speaker, or a display screen.

7. The electronic device according to any one of claims 1-6, characterized in that, The foldable electronic device also includes at least one second functional device, and the flexible circuit board is further connected to at least one second functional device.

8. The electronic device according to any one of claims 1-7, characterized in that, The flexible circuit board is equipped with a stress-relief structure.

9. The electronic device according to claim 8, characterized in that, The flexible circuit board has a cutout portion, and the stress relief structure is the cutout portion; or, the flexible circuit board includes a redundant portion, and the stress relief structure is the redundant portion.

10. The electronic device according to any one of claims 1-9, characterized in that, The flexible circuit board includes a central portion, at least one first branch portion, and at least one second branch portion; the first branch portion is connected to the central portion, and the second branch portion is connected to either the central portion or the first branch portion. The foldable electronic device further includes a signal processing module and at least one third functional device; the signal processing module is disposed on the central portion and electrically connected to the central portion; At least one first branch is connected to at least one third functional device, and at least one second branch is connected to the second branch.

11. The electronic device according to any one of claims 1-10, characterized in that, The flexible circuit board is connected to the second branch via conductive adhesive, silver paste, or non-conductive adhesive; or, the flexible circuit board is connected to the second branch via a molten pool or hard interference.

12. The electronic device according to any one of claims 1-10, characterized in that, The foldable electronic device further includes a connector, which includes a first connector and a second connector that are connected to each other. The planes on which the first connector and the second connector are located have a preset angle. The first connector is connected to the flexible circuit board, and the second connector is connected to the second branch.

13. An electronic device, characterized in that, include: A border, at least a portion of which forms a first branch, the first branch being a radiator of the first antenna; The first antenna is used to operate in at least two operating frequency bands; A flexible circuit board, the flexible circuit board being connected to the first branch, and the flexible circuit board being grounded; The second tuning circuit is disposed on the flexible circuit board and electrically connected to the flexible circuit board. The second tuning circuit includes multiple second tuning links, which are used to enable the first stub to operate in at least two operating frequency bands.

14. The electronic device according to claim 13, characterized in that, The second tuning circuit includes a control terminal, which is used to receive different control signals and to activate different second tuning links based on the different control signals; When one of the multiple second tuning links is turned on, the first stub operates in at least one of the at least two operating frequency bands corresponding to the first stub.

15. The electronic device according to claim 13 or 14, characterized in that, At least a portion of the frame further forms a third branch, which is a radiator of the second antenna; the second antenna is used to operate in at least two operating frequency bands; The flexible circuit board is also connected to the third branch; The electronic device further includes a fourth tuning circuit, which is disposed on the flexible circuit board and electrically connected to the flexible circuit board; The fourth tuning circuit includes multiple fourth tuning links, and the fourth tuning circuit is used to enable the third stub to operate in at least two operating frequency bands.

16. The electronic device according to claim 13 or 14, characterized in that, At least a portion of the frame also forms a third branch, which is also a radiator of the first antenna; the flexible circuit board is also connected to the third branch.

17. The electronic device according to claim 14, characterized in that, The electronic device further includes a signal processing module, and the flexible circuit board is electrically connected to the signal processing module; the flexible circuit board is used to transmit the control signal sent by the signal processing module to the control terminal of the second tuning circuit. The flexible circuit board is also used to transmit the signal sent by the signal processing module to the first branch so as to radiate the signal through the first branch; or, the flexible circuit board is also used to transmit the signal received by the first branch to the signal processing module.

18. The electronic device according to any one of claims 13-17, characterized in that, The electronic device further includes a fourth functional device, with the first branch and the fourth functional device spaced apart, and the flexible circuit board located on one side of the fourth functional device along the thickness direction of the electronic device.

19. The electronic device according to claim 18, characterized in that, The fourth functional device is a battery, a speaker, or a display screen.

20. The electronic device according to any one of claims 13-19, characterized in that, The electronic device further includes at least one fifth functional device, and the flexible circuit board is also connected to at least one fifth functional device.

21. The electronic device according to any one of claims 13-20, characterized in that, The flexible circuit board is equipped with a stress-relief structure.

22. The electronic device according to claim 21, characterized in that, The flexible circuit board has a cutout portion, and the stress relief structure is the cutout portion; or, the flexible circuit board includes a redundant portion, and the stress relief structure is the redundant portion.

23. The electronic device according to any one of claims 13-22, characterized in that, The flexible circuit board includes a central portion, at least one first branch portion, and at least one second branch portion; the first branch portion is connected to the central portion, and the second branch portion is connected to either the central portion or the first branch portion. The electronic device further includes a signal processing module and at least one sixth functional device; the signal processing module is disposed on the central portion and electrically connected to the central portion; at least one first branch portion is connected to at least one sixth functional device, and at least one second branch portion is connected to the first branch.

24. The electronic device according to claim 23, characterized in that, The frame is made of a non-conductive structural material, the flexible circuit board is connected to the frame, and the portion of the flexible circuit board connected to the frame is reused as the first branch.

25. The electronic device according to claim 24, characterized in that, The frame is made of a non-conductive structural material, and the first branch is disposed on the side wall of the frame.

26. The electronic device according to claim 24 or 25, characterized in that, The frame material includes polyimide or polyethylene terephthalate.

27. The electronic device according to claim 26, characterized in that, The electronic device includes a flexible electronic device.

28. The electronic device according to any one of claims 13-23, characterized in that, The flexible circuit board is connected to the first branch through conductive adhesive, silver paste or non-conductive adhesive; or, the flexible circuit board is connected to the first branch through a molten pool or hard interference.

29. The electronic device according to any one of claims 13-23, characterized in that, The electronic device further includes a connector, which includes a first connector and a second connector that are connected to each other. The planes on which the first connector and the second connector are located have a preset angle. The first connector is connected to the flexible circuit board, and the second connector is connected to the first branch.

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