Foldable electronic device

Abstract

The application provides a foldable electronic device. The foldable electronic device comprises a foldable main body and an antenna assembly. The foldable main body comprises a first main body and a second main body which are foldable to present a folded state and an unfolded state. The antenna assembly comprises a first radiator, a second radiator and a feed source. The first radiator is arranged corresponding to the first main body and has a feed point. The feed source is electrically connected to the feed point. The second radiator is arranged corresponding to the second main body. When the first and second main bodies are in the unfolded state, the first and second radiators are located on the same side of the foldable electronic device. The first radiator is excited to generate a first resonant mode which supports a first frequency band. When the first and second main bodies are in the folded state, the second and first radiators are at least partially overlapped and coupled. The first and second radiators are excited to generate a second resonant mode to support the first frequency band. The second radiator is excited to generate a first resonant current I1. The first radiator is excited to generate a second resonant current I2 which is opposite to the first resonant current I1, and I2

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of communication, in particular to a foldable electronic device. BACKGROUND

[0002] Electronic devices with unfolded state and folded state are more and more widely concerned due to the large display screen in the unfolded state and the small space occupation and portability in the folded state. However, the performance of the antenna is seriously degraded after the electronic device is folded, which affects the user experience. Therefore, how to improve the antenna performance of the foldable electronic device in the unfolded and folded states becomes a technical problem to be solved. SUMMARY

[0003] In a first aspect, the present application provides a foldable electronic device. The foldable electronic device includes a foldable main body and an antenna assembly. The foldable main body includes a first main body and a second main body, so that the foldable electronic device presents a folded state and an unfolded state. The antenna assembly includes:

[0004] a first radiator corresponding to the first main body, the first radiator having a feed point;

[0005] a feed source electrically connected to the feed point; and

[0006] a second radiator corresponding to the second main body;

[0007] When the foldable electronic device is in the unfolded state, the first radiator and the second radiator are located on the same side of the foldable electronic device, and the first radiator is excited to generate a first resonant mode, wherein the first resonant mode supports a first frequency band in a preset frequency band range.

[0008] When the foldable electronic device is in the folded state, the second radiator and the first radiator are at least partially stacked and coupled, the first radiator and the second radiator are excited to generate a second resonant mode, wherein the second radiator is excited to generate a first resonant current, the first radiator is excited to generate a second resonant current opposite to the first resonant current, and the current value of the second resonant current is less than the current value of the first resonant current, and the second resonant mode supports the first frequency band in the preset frequency band range.

[0009] In summary, the foldable electronic device provided by the embodiments of the present application, when the foldable electronic device is in the unfolded state, the first radiator serves as the main branch supporting the first frequency band in the antenna assembly. When the foldable electronic device is in the folded state, the working environment of the first radiator changes compared to when the foldable electronic device is in the unfolded state. Therefore, when the foldable electronic device is in the folded state, using the second radiator coupled with the first radiator as the main branch supporting the first frequency band can reduce or even avoid the decline in the antenna performance of the first frequency band due to the folding of the foldable electronic device, so that the foldable electronic device still has good antenna performance in the first frequency band when it is in the folded state.

[0010] In addition, because the first resonant current of the second radiator and the second resonant current are opposite in current direction when the foldable electronic device is in the folded state, the magnetic field signal corresponding to the first resonant current on the second radiator and the magnetic field signal corresponding to the second resonant current on the first radiator are partially offset. Therefore, compared to the case where there is no second resonant current opposite to the first resonant current on the first radiator, the foldable electronic device provided by the embodiments of the present application can reduce the electromagnetic wave signal absorbed by the human body when it is in the folded state, thereby playing a role in reducing the specific absorption rate (SAR). The foldable electronic device provided by the embodiments of the present application can ensure that the user folds the foldable electronic device and holds it close to the user, and can play a role in reducing the SAR when working in the first frequency band. BRIEF DESCRIPTION OF DRAWINGS

[0011] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0012] Figure 1 A structural schematic diagram of a foldable electronic device provided by an embodiment of the present application;

[0013] Figure 2 A perspective exploded view of the foldable electronic device shown in Figure 1

[0014] Figure 3 A structural schematic diagram of the sliding folding of the first main body and the second main body in the foldable electronic device provided by an embodiment of the present application;

[0015] Figure 4 ​A schematic diagram of the structure of the first main body and the second main body in the foldable electronic device provided in the embodiments of this application, showing their rotational folding;

[0016] Figure 5 A partial structural schematic diagram of the foldable electronic device provided in an embodiment of this application in its unfolded state;

[0017] Figure 6 for Figure 5 A three-dimensional structural diagram of a portion of the foldable electronic device shown in the diagram when it is in a folded state.

[0018] Figure 7 for Figure 5 A side view of part of the structure of the foldable electronic device provided in the image when it is in a folded state;

[0019] Figure 8 for Figure 6 A schematic diagram of the first resonant current and the second resonant current in the foldable electronic device shown.

[0020] Figure 9 for Figure 6 A schematic diagram of the third and fourth resonant currents in the foldable electronic device shown.

[0021] Figure 10 A schematic diagram of the feature module of the motherboard of the foldable electronic device 1 provided in one embodiment of this application when it is in a folded state;

[0022] Figure 11 for Figure 5 A schematic diagram of the fifth resonant current in the foldable electronic device shown.

[0023] Figure 12 for Figure 5 A schematic diagram of the sixth resonant current in the foldable electronic device shown;

[0024] Figure 13 for Figure 5 A schematic diagram of the coupling gap when the foldable electronic device is in the unfolded state;

[0025] Figures 14-21 Schematic diagrams of the first matching circuit and the second matching circuit provided in various embodiments;

[0026] Figure 22 A schematic diagram of the first matching circuit in a foldable device provided according to an embodiment of this application;

[0027] Figure 23 A schematic diagram illustrating the efficiency of a foldable electronic device in an unfolded state, as provided in one embodiment.

[0028] Figure 24Efficiency diagram of the foldable electronic device in a folded state according to an embodiment;

[0029] Figure 25 S-parameter, system total efficiency and system radiation efficiency simulation curve diagram of the foldable electronic device in a folded state according to an embodiment;

[0030] Figure 26 System total efficiency and system radiation efficiency simulation curve diagram of the foldable electronic device in a folded state and an unfolded state according to an embodiment.

[0031] Explanation of main element labels:

[0032] Foldable electronic device 1, foldable body 10, first body 11, electrical connection 12, first free edge 111, first connecting edge 112, first side edge 113, second side edge 114, second body 13, second free edge 131, second connecting edge 132, third side edge 133, fourth side edge 134, coupling gap 11a, coupling gap 11b;

[0033] Antenna assembly 20, first radiator 21, feed point P, first free end 21, first ground end 211, first free end 212, feed source S, second radiator 22, second ground end 221, second free end 222;

[0034] Floor 30, first matching circuit M1, second matching circuit M2, shell 40, first shell 41, second shell 42, flexible display screen 50, first fixed part 51, bending part 52, second fixed part 53;

[0035] Switch 610, matching sub-circuit 620, impedance matching sub-circuit 630, series unit 60a, first end 611, second end 612, control end 613;

[0036] First resonant current I1, second resonant current I2, third resonant current I3, fourth resonant current I4, fifth resonant current I5, sixth resonant current I6. DETAILED DESCRIPTION

[0037] The technical solutions of the present application will be described clearly and completely below with reference to the drawings. Obviously, the embodiments described in the present application are only part of the embodiments, not all the embodiments. Based on the embodiments provided in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor are within the scope of protection of the present application.

[0038] Reference to an "embodiment" in this application means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive or alternative embodiments. One skilled in the art will understand that embodiments described in this application can be combined with other embodiments in various ways.

[0039] The terms "first", "second", and the like, in the description and in the claims of the present application and in the above drawings, are used for distinguishing between similar objects and are not necessarily used to describe a particular sequential or chronological order. Moreover, the terms "comprises", "comprising", "includes", "including", or the like, when used in this specification and in the following claims, are intended to specify the presence of stated features, integers, steps, or components but do not preclude the presence or addition of one or more other features, integers, steps, components, or groups thereof.

[0040] Please refer to Figure 1 , Figure 1 A structural schematic diagram of a foldable electronic device is provided in an embodiment of the present application. The foldable electronic device 1 includes, but is not limited to, a device having a communication function and capable of being folded or unfolded, such as a mobile phone, a tablet computer, a notebook computer, a computer, a wearable device, a drone, and the like. The present application takes a mobile phone as an example for illustration, and other electronic devices can refer to the present embodiment.

[0041] For ease of description, please refer to Figure 2 , Figure 2 A partial exploded structural schematic diagram of the foldable electronic device 1 is provided in an embodiment of the present application. The thickness direction of the foldable electronic device 1 is defined as the Z-axis direction, the length direction is defined as the Y-axis direction, and the width direction is defined as the X-axis direction. The Z-axis, the Y-axis, and the X-axis are perpendicular to each other. The present application does not limit the size of the foldable electronic device 1 in the length direction and the width direction. In some embodiments, the size of the foldable electronic device 1 in the length direction is greater than that in the width direction, and in other embodiments, the size of the foldable electronic device 1 in the width direction is greater than, or equal to, that in the length direction.

[0042] For ease of description, please refer to Figure 2 and Figure 3 , Figure 2 A perspective exploded view of the foldable electronic device shown in Figure 1 ; Figure 3 A structural schematic diagram of the sliding folding of a first main body and a second main body in the foldable electronic device is provided in an embodiment of the present application. The foldable electronic device 1 provided in the present embodiment includes at least a foldable main body 10 and an antenna assembly 20.

[0043] Referring to Figure 3 The foldable main body 10 includes a first main body 11 and a second main body 13. The first main body 11 and the second main body 13 are movably connected to present a folded state or an unfolded state. In the embodiments of the present application, the movable connection is not limited to a sliding connection, or a rotating connection, or a combination of rotating and sliding, etc., so that the first main body 11 and the second main body 13 are changed from the folded state to the unfolded state, or from the unfolded state to the folded state.

[0044] The following describes the environment in which the foldable electronic device 1, the foldable main body 10, and the antenna assembly 20 are located, with reference to the accompanying drawings.

[0045] Referring to Figure 2 The foldable electronic device 1 further includes a housing 40. The housing 40 includes a first housing 41 and a second housing 42. The first housing 41 covers the outer side of the first main body 11, and the second housing 42 covers the outer side of the second main body 13. Each housing 40 includes a bottom plate (which can also be referred to as a back cover) and a frame surrounding the periphery of the bottom plate. The bottom plate and the frame surrounding the periphery thereof include a receiving space. The radiator (at least one of the first radiator 21 or the second radiator 22 described later) of the antenna assembly 20 can be part of the frame. The first main body 11 is arranged on the bottom plate of the first housing 41 (received in the first housing 41), and the second main body 13 is arranged on the bottom plate of the second housing 42 (received in the second housing 42). The receiving space is also used to receive the floor 30, the camera module, the receiver module, the battery, various sensors, etc. The material of the foldable main body 10 is a metal conductive material. The present application is not limited to the shape of the first main body 11 and the second main body 13. Alternatively, the first main body 11 can be substantially rectangular, and the second main body 13 can be substantially rectangular, and the shape is not specifically limited, including but not limited to rectangular, square, irregular, etc. The foldable main body 10 is provided with a through hole, a notch, a slot, etc. to receive the device.

[0046] The present application does not specifically limit the foldable main body 10, which can include but is not limited to a middle plate inside the middle frame of the foldable electronic device 1, etc. The middle plate is used to carry a circuit board, form a receiving slot for receiving electronic devices, and form an empty notch, etc. The middle plate can be a metal material, or a non-metal material, or a combination of metal and non-metal materials. When the middle plate is a metal material, such as magnesium-aluminum alloy, the middle plate can also serve as a reference ground system of the foldable electronic device 1.

[0047] In other embodiments, the floor and the frame are a split structure. The middle plate and the frame are an interconnected structure.

[0048] The foldable main body 10 includes a folded state or an unfolded state. In the folded state, the first main body 11 and the second main body 13 are stacked in the thickness direction (Z-axis direction), specifically, the first main body 11 and the second main body 13 are arranged in the upper and lower layers along the Z-axis direction.

[0049] In the unfolded state, the first main body 11 is translated from the folded state to overlap with the second main body 13 by an area less than a preset area, for example, 20%, 15%, 10%, 5%, 1%, 0% of the area of the first main body 11. At this time, the foldable electronic device 1 includes, but is not limited to, a slide phone.

[0050] Referring to Figure 3 , the first main body 11 and the second main body 13 are connected by a slide rail. For example, the slide rail extends along the Y-axis direction. The first main body 11 and / or the second main body 13 slides along the extension direction of the slide rail to the folded state or the unfolded state. In the folded state, the first main body 11 is located at the solid line position in Figure 3 , and in the unfolded state, the first main body 11 is located at the dashed line position in Figure 3 .

[0051] In the unfolded state, the first main body 11 is flipped from the folded state to overlap with the second main body 13 by an area less than a preset area, for example, 20%, 15%, 10%, 5%, 1%, 0% of the area of the first main body 11. At this time, the foldable electronic device 1 includes, but is not limited to, a folding phone.

[0052] Referring to Figure 4 , Figure 4 , the first main body 11 and the second main body 13 are connected by a rotating shaft. The axis direction of the rotating shaft is the X-axis direction. The first main body 11 and / or the second main body 13 rotates around the rotating shaft to the folded state or the unfolded state. In the folded state, the first main body 11 is located at the solid line position in Figure 4 , and in the unfolded state, the first main body 11 is located at the dashed line position in Figure 4 .

[0053] The embodiments of the present application take the rotating connection between the first main body 11 and the second main body 13 as an example for illustration.

[0054] Referring to Figure 2The foldable electronic device 1 also includes a flexible display screen 50. The flexible display screen 50 is located on the front side of the foldable main body 10 (the front side refers to the direction facing the user when the flexible display screen 50 is in normal use). The flexible display screen 50 includes a first fixing part 51, a bending part 52, and a second fixing part 53 arranged sequentially. The first fixing part 51 is fixedly connected to the first housing 41, and the second fixing part 53 is fixedly connected to the second housing 42; the fixing method includes, but is not limited to, adhesive bonding. The bending part 52 is located on the rotating connecting mechanism; the connection between the two can be a fixed connection or a non-connected state. The bending part 52 bends when the foldable electronic device 1 is in use, and its bending shape includes, but is not limited to, a teardrop shape or a U-shape.

[0055] Please refer to the following: Figure 5 , Figure 6 and Figure 7 , Figure 5 A partial structural schematic diagram of the foldable electronic device provided in an embodiment of this application in its unfolded state; Figure 6 for Figure 5 A three-dimensional structural diagram of a portion of the foldable electronic device shown in the diagram when it is in a folded state. Figure 7 for Figure 5 The image shows a side view of a portion of the structure of a foldable electronic device 1 in a folded state. The foldable electronic device 1 includes a foldable main body 10 and an antenna assembly 20. The foldable main body 10 includes a foldable first main body 11 and a foldable second main body 13 to allow the foldable electronic device 1 to be in a folded and unfolded state. The antenna assembly 20 includes a first radiator 21, a feed source S, and a second radiator 22. The first radiator 21 is disposed corresponding to the first main body 11 and has a feed point P. The feed source S is electrically connected to the feed point P. The second radiator 22 is disposed corresponding to the second main body 13. When the foldable electronic device 1 is in an unfolded state, the first radiator 21 and the second radiator 22 are located on the same side of the foldable electronic device 1, and the first radiator 21 is excited to generate a first resonant mode, wherein the first resonant mode supports a first frequency band. When the foldable electronic device 1 is in a folded state, the second radiator 22 is at least partially stacked and coupled to the first radiator 21, and the second radiator 22 is excited to generate a second resonant mode, wherein the second resonant mode supports the first frequency band within a preset frequency range.

[0056] Please see Figure 5The first body 11 includes a first connecting edge 112 and a first free edge 111 arranged oppositely. The first body 11 is substantially rectangular. The first connecting edge 112 and the first free edge 111 are edges of two ends along the Y-axis direction respectively. The first body 11 further includes a first side edge 113 and a second side edge 114 arranged oppositely and connected between the first free edge 111 and the first connecting edge 112. The first side edge 113 and the second side edge 114 are edges of two ends along the X-axis direction respectively.

[0057] Referring to Figure 5 The second body 13 includes a second connecting edge 132 and a second free edge 131 arranged oppositely. The second body 13 is substantially rectangular. The second connecting edge 132 and the second free edge 131 are edges of two ends along the Y-axis direction respectively. The second body 13 further includes a third side edge 133 and a fourth side edge 134 arranged oppositely and connected between the second free edge 131 and the second connecting edge 132. The third side edge 133 and the fourth side edge 134 are edges of two ends along the X-axis direction respectively.

[0058] Referring to Figure 5 The first body 11 and the second body 13 are both conductive members. That is, the first body 11 and the second body 13 are both conductive structures. When the first body 11 and the second body 13 are folded, the first body 11 and the second body 13 are arranged oppositely. The first body 11 and the second body 13 are similar to two pieces of conductive plate structures.

[0059] In an embodiment, the first connecting edge 112 and the second connecting edge 132 are rotatably electrically connected through an electrical connecting member 12. When the first body 11 is folded relative to the second body 13, the first body 11 and the second body 13 are folded in half. The first free edge 111 and the second free edge 131 are arranged in alignment and spaced apart. In other words, the first body 11 and the second body 13 have similar or identical lengths in the Y-axis direction.

[0060] Referring to Figure 5 When the foldable electronic device 1 is in the unfolded state, the first side edge 113 and the third side edge 133 are arranged in line or approximately in line, and the second side edge 114 and the fourth side edge 134 are arranged in line or approximately in line. When the foldable electronic device 1 is in the folded state, the first side edge 113 and the third side edge 133 are arranged in alignment and spaced apart; the second side edge 114 and the fourth side edge 134 are arranged in alignment and spaced apart, and the first free edge 111 and the second free edge 131 are arranged in alignment and spaced apart.

[0061] In the schematic diagram of the present embodiment, the first radiator 21 is arranged on one side of the first side edge 113, and the second radiator 22 is arranged on one side of the third side edge 133. When the foldable electronic device 1 is in an unfolded state, the first radiator 21 and the second radiator 22 are located on the right side of the foldable main body 10. It can be understood that the positions of the first radiator 21 and the second radiator 22 relative to the foldable main body 10 change as the placement posture of the foldable electronic device 1 changes.

[0062] The first radiator 21 can be a Laser Direct Structuring (LDS) radiator, or a Flexible Printed Circuit (FPC) radiator, or a Print Direct Structuring (PDS) radiator, or a metal branch radiator. When the antenna assembly 20 is applied to the foldable electronic device 1, the first radiator 21 can be a Mechanical Design Antenna (MDA) radiator designed by using the insert metal of the foldable electronic device 1 itself. For example, the first radiator 21 can be an antenna radiator designed by using the middle frame formed by the plastic and metal of the foldable electronic device 1. In addition, the first radiator 21 can also be a metal edge frame antenna radiator designed by using the metal middle frame.

[0063] It can be understood that the shape, structure and material of the first radiator 21 are not specifically limited in the present application. The shape of the first radiator 21 includes but is not limited to a bent shape, a straight shape, an L shape, a sheet shape, a rod shape, a coating, a film, etc. When the first radiator 21 is in a strip shape, the extension track of the first radiator 21 is not limited in the present application, so the first radiator 21 can extend in a straight line, a curve, multiple bends, etc. The first radiator 21 described above can be a line with uniform width in the extension track, or can be an irregular shape with different widths, such as a gradually changing width or a widened area.

[0064] The feeding source S can be electrically connected to the feeding point P in the following ways, but not limited to: the feeding source S is directly electrically connected to the feeding point P by welding, or indirectly electrically connected to the feeding point P by a coaxial line, a microstrip line, a conductive spring, conductive glue, etc.

[0065] The second radiator 22 can be a Laser Direct Structuring (LDS) radiator, or a Flexible Printed Circuit (FPC) radiator, or a Print Direct Structuring (PDS) radiator, or a metal branch radiator. When the antenna assembly 20 is applied to the foldable electronic device 1, the second radiator 22 can be a Mechanical Design Antenna (MDA) radiator designed by using the insert metal of the foldable electronic device 1 itself. For example, the second radiator 22 can be an antenna radiator designed by using the middle frame formed by the plastic and metal of the foldable electronic device 1. In addition, the second radiator 22 can also be a metal edge frame antenna radiator designed by the metal middle frame.

[0066] It can be understood that the shape, structure and material of the second radiator 22 are not limited in the present application, and the shape of the second radiator 22 includes but is not limited to a bending shape, a straight shape, an L shape, a sheet shape, a rod shape, a coating, a film, etc. When the second radiator 22 is in a strip shape, the extension track of the second radiator 22 is not limited in the present application, so the second radiator 22 can extend in a straight line, a curve, or multiple bending sections. The second radiator 22 described above can be a line with uniform width in the extension track, or can be an irregular shape with different widths, such as a gradually changing width or a widened area. The material of the second radiator 22 can be the same as or different from that of the first radiator 21, and the present application does not limit the embodiments.

[0067] The foldable electronic device 1 provided by the embodiments of the present application is in a folded state, the second radiator 22 is at least partially laminated with the first radiator 21, and the second radiator 22 is arranged apart from the first radiator 21 to form a coupling gap 11a, and the second radiator 22 can be coupled with the first radiator 21 through the coupling gap 11a.

[0068] When the foldable electronic device 1 is in an unfolded state, the first radiator 21 is excited by the feed source S to generate a first resonance mode, and the first resonance mode is used to support a first frequency band in the preset frequency band range. This will be described later in combination with the simulation diagram of the antenna assembly 20. When the foldable electronic device 1 is in an unfolded state, the first radiator 21 serves as a main radiation branch in the antenna assembly 20 supporting the first frequency band.

[0069] When the foldable electronic device 1 is in the unfolded state, the first radiator 21 acts as a main radiation branch in the antenna assembly 20 supporting the first frequency band. When the foldable electronic device 1 changes from the unfolded state to the folded state, the working environment of the first radiator 21 changes. If the first radiator 21 continues to act as the main radiation branch supporting the first frequency band, the antenna assembly 20 supporting the first frequency band has a relatively serious decline in antenna performance, such as a low radiation effect of the antenna assembly 20 supporting the first frequency band, thereby affecting the antenna performance of the antenna assembly 20 in the first frequency band. When the foldable electronic device 1 is in the folded state, the foldable electronic device 1 provided by the embodiment of the present application uses the second radiator 22 as a radiation branch supporting the first frequency band. The second radiator 22 is excited by the first radiator 21 to generate a second resonance mode, instead of continuing to use the first radiator 21 to support the first frequency band, so that the decline in the antenna performance of the first frequency band caused by the change of the foldable electronic device 1 from the unfolded state to the folded state can be overcome.

[0070] In summary, the foldable electronic device 1 provided by the embodiment of the present application uses the first radiator 21 as a main branch in the antenna assembly 20 supporting the first frequency band when the foldable electronic device 1 is in the unfolded state. When the foldable electronic device 1 is in the folded state, the working environment of the first radiator 21 changes compared to when the foldable electronic device 1 is in the unfolded state. Therefore, when the foldable electronic device 1 is in the folded state, using the second radiator 22 coupled with the first radiator 21 as a main branch supporting the first frequency band can reduce or even avoid the decline in the antenna performance of the first frequency band caused by the folding of the foldable electronic device 1, so that the foldable electronic device 1 still has good antenna performance in the first frequency band when it is in the folded state.

[0071] Next, the specific structure of the first radiator 21 and the second radiator 22 and the case where the foldable electronic device 1 is in the folded state will be described in detail. Please continue to refer to Figures 5 to 7The first radiator 21 includes a first ground end 211 and a first free end 212. The first ground end 211 is grounded, the feed point P is located between the first ground end 211 and the first free end 212, and the first ground end 211 is away from the second body 13 compared with the first free end 212. The second radiator 22 includes a second ground end 221 and the second free end 222. The second ground end 221 is grounded, and the second ground end 221 is adjacent to the first free end 212 compared with the second free end 222. When the foldable electronic device 1 is in the folded state: the second free end 222 corresponds to the first ground end 211, the second ground end 221 corresponds to the first free end 212, and a coupling gap 11a is formed between the second radiator 22 and the first radiator 21. In the direction in which the first body 11 points to the second body 13, the size W of the coupling gap 11a satisfies: 0.5mm≤W≤4.0mm.

[0072] The first ground end 211 is electrically connected to the ground pole of the foldable electronic device 1 to ground the first ground end 211. The grounding of the first ground end 211 includes but is not limited to the following embodiments. The way in which the first ground end 211 is electrically connected to the ground pole can include but is not limited to direct electrical connection (such as welding) or indirect electrical connection to the ground pole of the foldable electronic device 1 through a coaxial line, a microstrip line, a conductive spring, conductive glue, etc. In this embodiment, the first body 11 is a conductive component and can constitute a ground pole, so the first ground end 211 is electrically connected to the first body 11 to be grounded.

[0073] The second ground end 221 is electrically connected to the ground pole of the foldable electronic device 1 to ground the second ground end 221. The grounding of the second ground end 221 includes but is not limited to the following embodiments. The way in which the second ground end 221 is electrically connected to the ground pole can include but is not limited to direct electrical connection (such as welding) or indirect electrical connection to the ground pole of the foldable electronic device 1 through a coaxial line, a microstrip line, a conductive spring, conductive glue, etc. In this embodiment, the second body 13 is a conductive component and can constitute a ground pole, so the second ground end 221 is electrically connected to the second body 13 to be grounded.

[0074] For example, the coupling gap 11a can have a size W of 0.5 mm, or 1.0 mm, or 1.5 mm, or 2.0 mm, or 2.5 mm, or 3.0 mm, or 3.5 mm, or 4.0 mm, but not limited to. When the foldable electronic device 1 is in the folded state, in the direction of the first body 11 pointing to the second body 13, the size W of the coupling gap 11a satisfies: 0.5 mm≤W≤4.0 mm, so that the second radiator 22 can better couple the energy of the first radiator 21, has a better coupling effect, and thus the second radiator 22 has better antenna performance when supporting the first frequency band.

[0075] In the embodiment, when the first radiator 21 and the second radiator 22 are excited to generate a second resonance mode, the second resonance mode includes a quarter wavelength mode of the second radiator 22.

[0076] The quarter wavelength mode is also called a fundamental mode. The second resonance mode includes the quarter wavelength mode of the second radiator 22, that is, the second radiator 22 works in the fundamental mode. When the second radiator 22 works in the fundamental mode, the first radiator 21 and the second radiator 22 have better radiation efficiency when supporting the first frequency band of the preset frequency band range.

[0077] Specifically, please refer to Figure 8 , Figure 8 for Figure 6 the schematic diagram of the first resonance current and the second resonance current in the foldable electronic device. When the first radiator 21 and the second radiator 22 are excited to generate a second resonance mode: the second radiator 22 is excited to generate a first resonance current I1, the first radiator 21 is excited to generate a second resonance current I2 opposite to the first resonance current I1, and the current value of the second resonance current I2 is less than the current value of the first resonance current I1.

[0078] Specifically, in the schematic diagram of the embodiment, the first resonant current I1 is represented by a solid line, and the second resonant current I2 is represented by a dashed line. The current value of the second resonant current I2 is smaller than the current value of the first resonant current I1, in other words, in the antenna assembly 20 provided by the embodiment, the current corresponding to the quarter-wavelength mode on the second radiator 22 is dominant, accompanied by a reverse current with a smaller current intensity on the first radiator 21. Since the first resonant current I1 of the second radiator 22 and the second resonant current I2 are opposite in current direction, the magnetic field signal corresponding to the first resonant current I1 on the second radiator 22 and the magnetic field signal corresponding to the second resonant current I2 on the first radiator 21 are partially offset. Therefore, compared with the case where the second resonant current I2 opposite to the first resonant current I1 does not exist on the first radiator 21, the foldable electronic device 1 provided by the embodiment can reduce the electromagnetic wave signal absorbed by the human body when the foldable electronic device 1 is in the folded state, and thus can play a role in reducing the specific absorption rate (SAR). The foldable electronic device 1 provided by the embodiment can ensure that when the user folds the foldable electronic device 1 and holds it close to the user (for example, when it is placed in a pocket), the SAR can be reduced when working in the first frequency band. In addition, generally, the foldable electronic device 1 provided by the embodiment is used as the main working scenario in the unfolded state, at which time the antenna performance of the first frequency band is better.

[0079] In an embodiment, when the foldable electronic device 1 is in the unfolded state and the antenna assembly 20 supports the first frequency band, the SAR value of the foldable electronic device 1 is a first SAR value; when the foldable electronic device 1 is in the folded state and the antenna assembly 20 supports the first frequency band, the SAR value of the foldable electronic device 1 is a second SAR value, wherein the second SAR value is smaller than the first SAR value.

[0080] In the embodiment, since the first radiator 21 is excited to generate the second resonant current I2 opposite to the first resonant current I1 when the foldable electronic device 1 is in the folded state, the magnetic field signal corresponding to the first resonant current I1 on the second radiator 22 and the magnetic field signal corresponding to the second resonant current I2 on the first radiator 21 are partially offset, thereby reducing the SAR (i.e., the second SAR value) of the foldable electronic device 1 when it is in the folded state and supports the first frequency band, compared with the SAR value (i.e., the first SAR value) when the foldable electronic device 1 is in the unfolded state and supports the first frequency band (i.e., the second SAR value is smaller than the first SAR value), thereby reducing the radiation to the user.

[0081] When the foldable electronic device 1 is in a folded state, the first radiator 21 and the second radiator 22 are excited to support the third resonant mode in the preset frequency band range, wherein the resonant frequency point of the resonant band supported by the third resonant mode is located in the preset frequency band and is less than the resonant frequency point corresponding to the second resonant mode.

[0082] In this embodiment, when the first radiator 21 and the second radiator 22 are excited to support the third resonant mode of the preset frequency band range, the first radiator 21 and the second radiator 22 support the second frequency band of the preset frequency band range.

[0083] When the foldable electronic device 1 provided in this application is in a folded state, the resonant frequency of the third resonant mode is lower than the resonant frequency of the second resonant mode. In other words, the resonant frequency of the second frequency band supported by the first radiator 21 and the second radiator 22 in the third resonant mode is high, and the resonant frequency of the first frequency band supported by the first radiator 21 and the second radiator 22 in the first resonant mode is low. That is, the resonant frequency of the second frequency band is lower than the resonant frequency of the first frequency band. The antenna assembly 20 provided in this application, where the resonant frequency of the second frequency band is lower than the resonant frequency of the first frequency band, can help improve the bandwidth and radiation efficiency of the first radiator 21 and the second radiator 22 when supporting the first frequency band.

[0084] When the first radiator 21 and the second radiator 22 are excited to generate a third resonant mode, the third resonant mode includes the quarter-wavelength mode of the first radiator 21.

[0085] The quarter-wavelength mode, also known as the fundamental mode, includes the quarter-wavelength mode of the first radiator 21, meaning the first radiator 21 operates in the fundamental mode. When the first radiator 21 operates in the fundamental mode, it supports better radiation efficiency in the second frequency band within the preset frequency range.

[0086] Please see Figure 9 , Figure 9 for Figure 6 The diagram illustrates the third and fourth resonant currents in the foldable electronic device. When the first radiator 21 is excited to generate the third resonant mode, it has a third resonant current I3. When the second radiator 22 is excited, it generates a fourth resonant current I4 that is opposite to the third resonant current I3, and the current value of the fourth resonant current I4 is less than the current value of the third resonant current I3.

[0087] Specifically, in the schematic diagram of the embodiment, the third resonance current I3 is represented by a solid line, and the fourth resonance current I4 is represented by a dashed line. The current value of the fourth resonance current I4 is smaller than the current value of the third resonance current I3, in other words, when the first radiator 21 and the second radiator 22 are excited to generate the third resonance mode, the antenna assembly 20 provided by the embodiment of the application is mainly the current corresponding to the quarter-wave mode on the first radiator 21, accompanied by a smaller reverse current on the second radiator 22. Since the third resonance current I3 of the first radiator 21 and the fourth resonance current I4 are opposite in current direction, the magnetic field signal corresponding to the third resonance current I3 on the first radiator 21 and the magnetic field signal corresponding to the fourth resonance current I4 on the second radiator 22 are partially offset. Therefore, compared with the case where there is no fourth resonance current I4 opposite to the third resonance current I3 on the second radiator 22, the foldable electronic device 1 provided by the embodiment of the application can reduce the electromagnetic wave signal absorbed by the human body when in the folded state, thereby playing a role in reducing SAR. The foldable electronic device 1 provided by the embodiment of the application can ensure that when the user folds the foldable electronic device 1 and puts it in the pocket, the foldable electronic device 1 can work in the second frequency band and can play a role in reducing SAR. In addition, generally, the foldable electronic device 1 provided by the embodiment of the application is used as the main working scenario in the unfolded state, at this time, the performance of the antenna in the second frequency band is better.

[0088] Please refer to Figure 10 , Figure 10 is a schematic diagram of the characteristic mode of the main board of the foldable electronic device 1 in the folded state provided by an embodiment of the application. The foldable electronic device 1 further includes a ground plate 30. In the embodiment, the ground plate 30 is the ground of the main board of the foldable electronic device 1. It can be understood that in other embodiments, the ground plate 30 is also the front shell (also known as the middle frame) of the foldable electronic device 1, or is the conductive battery cover of the foldable electronic device 1, or is the shielding member (also known as the support member) of the display screen of the foldable electronic device 1, etc. When the foldable electronic device 1 is in the folded state, the antenna assembly 20 also supports a fourth resonance mode, wherein the fourth resonance mode supports a resonance frequency band in the preset frequency band, and the fourth resonance mode is a characteristic mode of the ground plate 30. When the ground plate 30 is the ground of the main board of the foldable electronic device 1, the fourth resonance mode is a characteristic mode of the main board.

[0089] In the embodiment, when the foldable electronic device 1 is in the folded state, the ground plate 30 of the foldable electronic device 1 is excited to support the fourth resonance mode, and the ground plate 30 supports a third frequency band in the preset frequency band range.

[0090] When the foldable electronic device 1 works in the third frequency band, the floor 30 serves as an antenna radiator, and functions to receive and transmit electromagnetic wave signals of the third frequency band in the preset frequency band range, and has good radiation efficiency. In addition, compared with directly receiving electromagnetic wave signals of the third frequency band by using a separate radiator, multiplexing the floor 30 of the foldable electronic device 1 as a radiator in the embodiment can reduce the number of radiators in the foldable electronic device 1, and further reduce the difficulty of device layout in the foldable electronic device 1.

[0091] In the embodiment, when the foldable electronic device 1 is in a folded state, the floor 30 of the foldable electronic device 1 is excited to generate a fourth resonance mode, supports the third frequency band of the preset frequency band range, so that the antenna assembly 20 has good communication effect in the preset frequency band range. In an embodiment, the resonance frequency point of the third frequency band is greater than the resonance frequency point of the second frequency band.

[0092] In an embodiment, the resonance current corresponding to the characteristic mode of the floor 30 is along the length direction of the foldable electronic device 1, and is a half-wavelength characteristic mode. In the embodiment, the length direction of the foldable electronic device 1 is the extension direction of the third side edge 133 of the foldable electronic device 1, and can also be regarded as the extension direction of the first side edge 113 in the foldable electronic device 1.

[0093] When the resonance current corresponding to the characteristic mode of the floor 30 is along the length direction of the foldable electronic device 1, and is a half-wavelength characteristic mode, it can be more conveniently excited, and the floor 30 can have good radiation efficiency in the third frequency band in the preset frequency band range.

[0094] Next, the case where the foldable electronic device 1 is in an unfolded state is described in detail.

[0095] Further, in the embodiment, the first resonance mode is a quarter-wavelength mode of the first radiator 21.

[0096] Please refer to Figure 11 , Figure 11 To Figure 5A fifth resonant current in the foldable electronic device is shown. When the first radiator 21 supports the first resonant mode, the first radiator 21 is excited to have a fifth resonant current I5. The fifth resonant current I5 is distributed between the first ground end 211 and the first free end 212. In the schematic diagram of the embodiment, the fifth resonant current I5 is shown as flowing from the first ground end 211 to the first free end 212. It is understood that the fifth resonant current I5 is a periodically changing current, in one half of a period, the fifth resonant current I5 flows from the first ground end 211 to the first free end 212; in the other half of the period, the fifth resonant current I5 flows from the first free end 212 to the first ground end 211.

[0097] The quarter wavelength mode is also referred to as a base mode. When the first radiator 21 operates in the base mode, the first radiator 21 has better radiation efficiency when supporting the first frequency band in the preset frequency range.

[0098] Please continue to refer to Figure 5 When the foldable electronic device 1 is in the unfolded state, the second ground end 221 is spaced apart from the first free end 212 by a coupling gap 11b, and the second radiator 22 is coupled to the first radiator 21 through the coupling gap 11b. The second radiator 22 is excited to support a fifth resonant mode in the preset frequency range, and the resonant frequency point of the fifth resonant mode is less than the resonant frequency point of the first resonant mode.

[0099] In the embodiment, when the second radiator 22 is excited to support the fifth resonant mode in the preset frequency range, the second radiator 22 supports a second frequency band in the preset frequency range.

[0100] The foldable electronic device 1 provided by the embodiment has a fifth resonant mode with a resonant frequency point less than the resonant frequency point of the first resonant mode, in other words, the second radiator 22 supports a resonant frequency point, and the first radiator 21 supports a resonant frequency point. That is, the resonant frequency point of the second frequency band is less than the resonant frequency point of the first frequency band. The antenna assembly 20 provided by the embodiment has a resonant frequency point of the second frequency band less than the resonant frequency point of the first frequency band, which can be beneficial to improve the bandwidth and radiation efficiency of the first radiator 21 supporting the first frequency band.

[0101] The fifth resonant mode is a quarter wavelength mode of the second radiator 22.

[0102] Please refer to Figure 12 , Figure 12 To Figure 5A schematic diagram of the sixth resonant current in the foldable electronic device shown in The second radiator 22 supports the fifth resonant mode, the second radiator 22 is excited by a sixth resonant current I6. The sixth resonant current I6 is distributed between the second ground end 221 and the second free end 222. In the schematic diagram of the embodiment, the sixth resonant current I6 is shown as flowing from the second ground end 221 to the second free end 222. It is understood that the sixth resonant current I6 is a periodically changing current, in one half of a period, the sixth resonant current I6 flows from the second ground end 221 to the second free end 222; in the other half of a period, the sixth resonant current I6 flows from the second free end 222 to the second ground end 221.

[0103] It is understood that the fifth resonant current I5 on the first radiator 21 when the first radiator 21 supports the first resonant mode has the same flow direction as the sixth resonant current I6 on the second radiator 22 when the second radiator 22 supports the fifth resonant mode. In Figure 11 and Figure 12 In the schematic diagram of the embodiment, the flow direction of the fifth resonant current I5 and the sixth resonant current I6 is upward (viewing angle) in one half of a period, and is downward (viewing angle) in the other half of a period.

[0104] The fifth resonant mode is a quarter wavelength mode of the second radiator 22, i.e., the second radiator 22 operates in a fundamental mode. When the second radiator 22 operates in the fundamental mode, the second radiator 22 has better radiation efficiency when supporting the second frequency band in the preset frequency range.

[0105] Please refer to Figure 5 and Figure 13 , Figure 13 is Figure 5 A schematic diagram of the coupling gap when the foldable electronic device shown in In an embodiment, when the foldable electronic device 1 is in the unfolded state, the size d of the coupling gap 11b along the arrangement direction of the first body 11 and the second body 13 satisfies: 5mm≤d≤10mm.

[0106] The size of the coupling gap 11b can be, but is not limited to, 5mm, or 6mm, or 7mm, or 8mm, or 9mm, or 10mm.

[0107] When the coupling gap 11b is too small, for example, less than 5 mm, the first radiator 21 and the second radiator 22 are likely to interfere when the foldable electronic device 1 is in the unfolded state and the first body 11 and the second body 13 are folded relative to each other, which may damage the first radiator 21 and the second radiator 22. When the coupling gap 11b is too large, for example, greater than 10 mm, the coupling effect between the second radiator 22 and the first radiator 21 is not good, so that the second radiator 22 cannot couple more energy from the first radiator 21, which further causes the antenna performance of the second radiator 22 supporting the second frequency band to decrease, in addition, the increasing effect of the second radiator 22 on the bandwidth of the first frequency band supported by the first radiator 21 also decreases, and the improvement of the radiation efficiency of the first frequency band supported by the first radiator 21 also decreases. In the foldable electronic device 1 provided by the embodiment of the present application, the size d of the coupling gap 11b along the arrangement direction of the first body 11 and the second body 13 satisfies 5 mm≤d≤10 mm, on the one hand, when the foldable electronic device 1 is in the unfolded state and the first body 11 and the second body 13 are folded relative to each other, the first radiator 21 and the second radiator 22 are not likely to interfere, and the first radiator 21 and the second radiator 22 are not likely to be damaged; on the other hand, the second radiator 22 can couple more energy from the first radiator 21, which ensures that the first frequency band supported by the second radiator 22 has a larger bandwidth and a higher radiation efficiency.

[0108] Please continue to refer to Figure 5 The antenna assembly 20 further includes a first matching circuit M1 and a second matching circuit M2. One end of the first matching circuit M1 is electrically connected to the feed point P, and the other end of the first matching circuit M1 is electrically connected to a feed source S, and the first matching circuit M1 is used to adjust the electrical length of the first radiator 21. One end of the second matching circuit M2 is electrically connected to the second ground end 221, and the other end of the second matching circuit M2 is grounded, and the second matching circuit M2 is used to adjust the electrical length of the second radiator 22.

[0109] In an embodiment, the first matching circuit M1 includes a switch and a matching device (also referred to as a matching sub-circuit). The matching device can be, but is not limited to, at least one of a variable capacitor or an inductor. For example, in an embodiment, the first matching circuit M1 can include a switch and a variable capacitor, etc.; and the second matching circuit M2 can include a switch and a variable capacitor, etc. In another embodiment, the first matching circuit M1 can include a switch, a variable capacitor, or an inductor, etc.; and the second matching circuit M2 can include a switch, a variable capacitor, or an inductor, etc.

[0110] Correspondingly, in an embodiment, the second matching circuit M2 comprises a switch and a matching device (also referred to as a matching sub-circuit). The matching device can be, but is not limited to, at least one of a variable capacitance or an inductance. For example, in an embodiment, the second matching circuit M2 can comprise a switch and a variable capacitance, etc. The second matching circuit M2 can comprise a switch and a variable capacitance, etc. In another embodiment, the second matching circuit M2 can comprise a switch, a variable capacitance, or an inductance, etc. The second matching circuit M2 can comprise a switch, a variable capacitance, or an inductance, etc.

[0111] In another embodiment, the switch in the first matching circuit M1 can comprise a single-pole single-throw (SPST) switch. When the foldable electronic device 1 is in the folded state: the switch and the matching device can be used in cooperation to adjust the electrical length of the first radiator 21, thereby adjusting the second frequency band supported by the first radiator 21, or adjusting the resonant frequency point of the second frequency band supported by the first radiator 21.

[0112] Correspondingly, in another embodiment, the switch in the second matching circuit M2 can comprise a single-pole single-throw (SPST) switch. When the foldable electronic device 1 is in the folded state: the switch and the matching device can be used in cooperation to adjust the electrical length of the second radiator 22, thereby adjusting the first frequency band supported by the second radiator 22, or adjusting the resonant frequency point of the first frequency band supported by the second radiator 22.

[0113] The specific circuit structure of the first matching circuit M1 and the second matching circuit M2 will be described below.

[0114] Please refer to Figures 14 to 21 , Figures 14-21 The schematic diagrams of the first matching circuit and the second matching circuit provided by each embodiment, respectively. The matching sub-circuit 620 in the first matching circuit M1 (or the second matching circuit M2) comprises one or more of the following circuits.

[0115] Please refer to Figure 14 , in Figure 14 , the matching sub-circuit 620 in the first matching circuit M1 (or the second matching circuit M2) comprises a band-pass circuit formed by the inductance L0 and the capacitance C0 in series.

[0116] Please refer to Figure 15 , in Figure 15 , the matching sub-circuit 620 in the first matching circuit M1 (or the second matching circuit M2) comprises a band-stop circuit formed by the inductance L0 and the capacitance C0 in parallel.

[0117] Please refer to Figure 16 , in Figure 16 , the matching sub-circuit 620 in the first matching circuit M1 (or the second matching circuit M2) comprises an inductor L0, a first capacitor C1, and a second capacitor C2. The inductor L0 is connected in parallel with the first capacitor C1, and the second capacitor C2 is electrically connected to a node at which the inductor L0 and the first capacitor C1 are electrically connected.

[0118] Please refer to Figure 17 , in Figure 17 , the matching sub-circuit 620 in the first matching circuit M1 (or the second matching circuit M2) comprises a capacitor C0, a first inductor L1, and a second inductor L2. The capacitor C0 is connected in parallel with the first inductor L1, and the second inductor L2 is electrically connected to a node at which the capacitor C0 and the first inductor L1 are electrically connected. Figure 18 , in Figure 18 , the matching sub-circuit 620 in the first matching circuit M1 (or the second matching circuit M2) comprises an inductor L0, a first capacitor C1, and a second capacitor C2. The inductor L0 is connected in series with the first capacitor C1, and one end of the second capacitor C2 is electrically connected to a first end of the inductor L0 that is not connected to the first capacitor C1, and the other end of the second capacitor C2 is electrically connected to a first end of the first capacitor C1 that is not connected to the inductor L0.

[0119] Please refer to Figure 19 , in Figure 19 , the matching sub-circuit 620 in the first matching circuit M1 (or the second matching circuit M2) comprises a capacitor C0, a first inductor L1, and a second inductor L2. The capacitor C0 is connected in series with the first inductor L1, one end of the second inductor L2 is electrically connected to a first end of the capacitor C0 that is not connected to the first inductor L1, and the other end of the second inductor L2 is electrically connected to a first end of the first inductor L1 that is not connected to the capacitor C0.

[0120] Please refer to Figure 20 , in Figure 20 , the matching sub-circuit 620 in the first matching circuit M1 (or the second matching circuit M2) comprises a first capacitor C1, a second capacitor C2, a first inductor L1, and a second inductor L2. The first capacitor C1 is connected in parallel with the first inductor L1, the second capacitor C2 is connected in parallel with the second inductor L2, and one end of the entirety formed by the second capacitor C2 and the second inductor L2 being connected in parallel is electrically connected to one end of the entirety formed by the first capacitor C1 and the first inductor L1 being connected in parallel.

[0121] Please refer to Figure 21 , in Figure 21In the first matching circuit M1 (or the second matching circuit M2), the matching sub-circuit 620 includes a first capacitor C1, a second capacitor C2, a first inductor L1, and a second inductor L2. The first capacitor C1 and the first inductor L1 are connected in series to form a first unit 113b. The second capacitor C2 and the second inductor L2 are connected in series to form a second unit 113c. The first unit 113b and the second unit 113c are connected in parallel.

[0122] A foldable electronic device according to an embodiment of the present application is described below. Please refer to Figure 22 , Figure 22 A schematic diagram of a first matching circuit in a foldable electronic device according to an embodiment of the present application is shown in FIG. 6. In the first matching circuit M1 (or the second matching circuit M2), the matching sub-circuit 620 includes a first capacitor C1, a second capacitor C2, a first inductor L1, and a second inductor L2. The first capacitor C1 and the first inductor L1 are connected in series to form a first unit 113b. The second capacitor C2 and the second inductor L2 are connected in series to form a second unit 113c. The first unit 113b and the second unit 113c are connected in parallel. Figure 22 (a) in FIG. 6 is a schematic diagram of the first matching circuit when the switch is off. Figure 22 (b) in FIG. 6 is a schematic diagram of the first matching circuit when the switch is on. In this embodiment, the first matching circuit M1 includes a switch 610 and a matching sub-circuit 620. The matching sub-circuit 620 and the switch 610 are connected in series to form a series unit 60a. One end of the series unit 60a is electrically connected to the feeding point P. The other end of the series unit 60a is grounded. When the foldable electronic device 1 is in the unfolded state, the switch 610 is off. The first radiator 21 is excited to generate the first resonant mode. When the foldable electronic device 1 is in the folded state, the switch 610 is on. The second radiator 22 is excited to generate the first resonant current.

[0123] In this embodiment, the first end 611 is electrically connected to the feeding point P. The second end 612 is electrically connected to the matching sub-circuit 620 to ground. It can be understood that in other embodiments, one end of the matching sub-circuit 620 is electrically connected to the feeding point P. The other end of the matching sub-circuit 620 is electrically connected to the switch 610 to ground. In the schematic diagram of this embodiment, the switch 610 is a single-pole single-throw switch 610. The switch 610 includes a first end 611, a second end 612, and a control end 613. When the control end 613 is disconnected from the first end 611 and the second end 612, the switch 610 is off. When the control end 613 is electrically connected to the first end 611 and the second end 612, the switch 610 is on. The matching sub-circuit 620 can refer to the foregoing description and will not be described here again.

[0124] In the schematic diagram of the embodiment, the first matching circuit M1 further comprises an impedance matching sub-circuit 630, and the first feed source S1 is electrically connected to the impedance matching sub-circuit 630 to the feeding point P. The impedance matching sub-circuit 630 is used to match the output impedance of the first feed source S1 and the input impedance of the first radiator 21, so that the excitation signal output by the feed source S1 can be output to the first radiator 21 more.

[0125] When the foldable electronic device 1 is in the unfolded state, the switch 610 is turned off, the matching sub-circuit 620 is not electrically connected in the path of the first radiator 21, and the first radiator 21 is excited to generate a first resonant mode. When the foldable electronic device 1 is in the folded state, the switch 610 is turned on, the matching sub-circuit 620 is electrically connected in the path of the first radiator 21, and the matching sub-circuit 620 adjusts the electrical length of the first radiator 21, so that the first radiator 21 is no longer a main branch supporting the first frequency band, and the second radiator 22 is used as a main radiation branch when the foldable electronic device 1 is in the folded state. Therefore, when the foldable electronic device 1 is in the folded state, using the second radiator 22 coupled with the first radiator 21 as a main branch supporting the first frequency band can reduce or even avoid the decline of the antenna performance of the first frequency band due to the folding of the foldable electronic device 1, so that the foldable electronic device 1 still has good antenna performance in the first frequency band when it is in the folded state.

[0126] Specifically, when the foldable electronic device 1 is in the unfolded state, the ground of the foldable electronic device 1 is large. When the foldable electronic device 1 is in the folded state, the ground of the foldable electronic device 1 becomes small, and the ground of the foldable electronic device 1 in the folded state is halved compared to the ground of the foldable electronic device 1 in the unfolded state. Influenced by the halving of the ground of the foldable electronic device 1, the system total efficiency and the system radiation efficiency of the mode supported by the first radiator 21 (i.e. the third resonant mode) are both reduced. At this time, through the switching of the switch, the switch 610 is turned on, and the matching sub-circuit 620 is electrically connected to the feeding point P, so that the second radiator 22 is used as a main radiation branch supporting the first frequency band. When the foldable electronic device 1 is in the folded state, using the second radiator 22 as a main radiation branch supporting the first frequency band has higher system radiation efficiency and higher system total efficiency.

[0127] In the embodiment, the preset frequency band range is a low frequency (Low Band, LB) frequency band, and the first frequency band is an N28 frequency band.

[0128] In the embodiment, the preset frequency band range is the LB frequency band, and the first frequency band is the N28 frequency band, so that the foldable electronic device 1 can communicate with other devices in the N28 frequency band of the low frequency band.

[0129] In other embodiments, the preset frequency band range can also be a middle high band (MHB) or the like.

[0130] The first body 11 and the second body 13 are both conductive structures. When the foldable body 10 is in the unfolded state: the first body 11 and the second body 13 are electrically connected, the first body 11 and the second body 13 constitute a radiation arm of a dipole antenna, and the other radiation arm of the dipole antenna at least includes the first radiator 21, wherein the dipole antenna supports the first frequency band.

[0131] In the embodiment, when the foldable body 10 is in the unfolded state, the first body 11 and the second body 13 are electrically connected, and the first body 11 and the second body 13 constitute at least part of a ground in the foldable electronic device 1. The at least part of the ground constitutes one radiation arm of the dipole antenna, which can be beneficial to reduce the size of the first radiator 21.

[0132] Next, the performance of the antenna assembly 20 in the foldable electronic device 1 provided by the embodiment of the application is simulated and described.

[0133] Please refer to Figure 23 , Figure 23An efficiency diagram of the foldable electronic device in an unfolded state is provided for an embodiment. In the diagram of the embodiment, the horizontal axis is frequency (Frequency) in GHz, and the vertical axis is in dB. Curve ① is a system radiation efficiency (System Rad. Efficiency) curve of the antenna assembly 20 of the foldable electronic device 1 without the second radiator 22, marked as System Rad. Efficiency without parasitic in the diagram; curve ② is a system radiation efficiency curve of the antenna assembly 20 of the foldable electronic device 1 with the second radiator 22, marked as System Rad. Efficiency with parasitic branch in the diagram; curve ③ is a system total efficiency (System Tot. Efficiency) curve of the antenna assembly 20 of the foldable electronic device 1 without the second radiator 22, marked as System Tot. Efficiency without parasitic in the diagram; and curve ④ is a system efficiency curve of the antenna assembly 20 of the foldable electronic device 1 with the second radiator 22, marked as System Tot. Efficiency with parasitic branch in the diagram. It should be noted that the antenna assembly 20 with the first radiator 21 and without the second radiator 22 can be regarded as the first radiator 21 working alone in the antenna assembly 20. As can be seen from the simulation diagram, when the foldable electronic device 1 is in an unfolded state: the antenna assembly 20 includes the first radiator 21 and the second radiator 22, that is, the radiation efficiency and total efficiency of the first frequency band supported by the antenna assembly 20 are improved after the second radiator 22 is added to the antenna assembly 20 including the first radiator 21.

[0134] See Figure 24 , Figure 24An efficiency diagram of the foldable electronic device in the folded state is provided. In the diagram of the embodiment, the horizontal axis is frequency (Frequency) in GHz, and the vertical axis is in dB. Curve ① represents the S parameter (S1,1); curve ② represents the system radiation efficiency (System Rad. Efficiency) curve of the antenna assembly 20 of the foldable electronic device 1; and curve ③ represents the system total efficiency (System Tot. Efficiency) curve of the antenna assembly 20 of the foldable electronic device 1. As shown in curve ①, the foldable electronic device 1 has three resonance modes in the folded state, in order from left to right: a third resonance mode, a second resonance mode, and a fourth resonance mode. As shown in the simulation diagram, in this embodiment, the first frequency band supported by the second resonance mode is the N28 frequency band. The first frequency band has a high system radiation efficiency and a high system total efficiency. The system radiation efficiency of the third resonance mode (i.e., the first mode on the left) is lower than that of the second resonance mode, and the system total efficiency of the third resonance mode is lower than that of the second resonance mode. The specific reasons are as follows. Generally, the first body 11 and the second body 13 are electrically conductive, so the first body 11 and the second body 13 can act as the ground (e.g., the main ground) of the foldable electronic device 1. When the foldable electronic device 1 is in the unfolded state, the ground of the foldable electronic device 1 is large. When the foldable electronic device 1 is in the folded state, the first body 11 and the second body 13 are folded, and the ground of the foldable electronic device 1 becomes small. When the sizes of the first body 11 and the second body 13 are equal or approximately equal, the ground of the foldable electronic device 1 in the folded state is halved compared to the ground of the foldable electronic device 1 in the unfolded state. Influenced by the halving of the ground of the foldable electronic device 1, the system total efficiency and the system radiation efficiency of the mode (i.e., the third resonance mode) supported by the first radiator 21 are both reduced. At this time, the second radiator 22 acts as the main radiation branch that supports the first frequency band, for example, the electrical length of the second radiator 22 itself can support the first frequency band, or at least one of the first matching circuit M1 and the second matching circuit M2 is adjusted (for example, the switches in the corresponding matching circuit are switched to adjust the matching devices loaded on the corresponding radiators) so that the second radiator 22 acts as the main radiation branch that supports the first frequency band. As shown in the simulation diagram, when the foldable electronic device 1 is in the folded state, using the second radiator 22 as the main radiation branch that supports the first frequency band has a high system radiation efficiency and a high system total efficiency.

[0135] See Figure 25 , Figure 25The simulation curve of the S parameter, the system total efficiency and the system radiation efficiency of the foldable electronic device in the folded state is provided. In the simulation curve, the horizontal coordinate is frequency (Frequency) in GHz, and the vertical coordinate is in dB. Curve ① is the simulation curve of the S parameter (S1,1) of the foldable electronic device 1 in the folded state; curve ①' is the simulation curve of the S parameter (S1,1) of the foldable electronic device 1 in the folded state without the second radiator 22 (referred to as parasitic-free); curve ② is the system radiation efficiency (System Rad. Efficiency) curve of the foldable electronic device 1 in the folded state, and curve ②' is the system radiation efficiency of the foldable electronic device 1 in the folded state without parasitic; curve ③ is the system total efficiency (System Tot. Efficiency) curve of the foldable electronic device 1 in the folded state, and curve ③' is the system total efficiency curve of the foldable electronic device 1 in the folded state without parasitic. It can be seen from the simulation curve that the system total radiation efficiency of the foldable electronic device 1 in the folded state provided by the embodiment is improved by about 3 dB (the absolute value of the difference between -7.003302 and -3.4836598) compared with the system total radiation efficiency of the foldable electronic device 1 in the folded state without parasitic.

[0136] Please refer to Figure 26 , Figure 26 The simulation curve of the system total efficiency and the system radiation efficiency of the foldable electronic device in the unfolded state and the folded state is provided. Curve ① is the system radiation efficiency (System Rad. Efficiency) curve of the foldable electronic device 1 in the unfolded state, and curve ② is the system radiation efficiency of the foldable electronic device 1 in the folded state; curve ①' is the system total efficiency (System Tot. Efficiency) curve of the foldable electronic device 1 in the unfolded state, and curve ②' is the system total efficiency curve of the foldable electronic device 1 in the folded state. It can be seen that the efficiency of the foldable electronic device 1 in the unfolded state in the first frequency band (for example, the N28 frequency band with a resonance frequency point of 0.75 GHz) is -4.2 dB, and the efficiency of the foldable electronic device 1 in the folded state in the first frequency band (for example, the N28 frequency band with a resonance frequency point of 0.75 GHz) is -7.2 dB, and the efficiency decreases by 3 dB, which is much better than the decrease of 6 dB to 10 dB in the related art.

[0137] In summary, the antenna assembly 20 of the foldable electronic device 1 provided by the embodiments of the present application increases the second radiator 22 (also referred to as a parasitic branch), and uses the second radiator 22 as the main radiation branch when the foldable electronic device 1 is in the folded state, so as to improve the efficiency of the first frequency band of the preset frequency band range (such as the LB frequency band) of the foldable electronic device 1 in the folded scenario, and significantly reduce the efficiency reduction of the first frequency band (such as the N28 frequency band) of the preset frequency band range.

[0138] In an embodiment, the second radiator 22 (also referred to as a parasitic branch) has a relatively long length. By increasing the relatively long second radiator 22 and by switching of the matching device in at least one of the first matching circuit M1 and the second matching circuit M2, and using the second radiator 22 as the main radiation branch when the foldable electronic device 1 is in the folded state, the efficiency of the first frequency band (such as the N28 frequency band) of the preset frequency band range (such as the LB frequency band) of the foldable electronic device 1 in the folded scenario can be improved, and the efficiency reduction of the first frequency band of the preset frequency band range can be significantly reduced.

[0139] The above describes some embodiments of the present application. It should be noted that those skilled in the art can make some improvements and refinements without departing from the principles of the present application, and these improvements and refinements are also considered to be within the protection scope of the present application.

Claims

1. A foldable electronic device, characterized by, The foldable electronic device includes a foldable main body and an antenna assembly, the foldable main body includes a foldable first main body and a second main body to make the foldable electronic device present a folded state and an unfolded state; the antenna assembly includes: a first radiator corresponding to the first main body, the first radiator having a feed point; a feed source electrically connected to the feed point; and a second radiator corresponding to the second main body; When the foldable electronic device presents an unfolded state, the first radiator and the second radiator are located on the same side of the foldable electronic device, and the first radiator is excited to generate a first resonance mode, wherein the first resonance mode supports a first frequency band of a preset frequency band range; When the foldable electronic device presents a folded state, the second radiator at least partially overlaps and couples with the first radiator, the first radiator and the second radiator are excited to generate a second resonance mode, wherein the second radiator is excited to generate a first resonance current, the first radiator is excited to generate a second resonance current opposite to the first resonance current, and the current value of the second resonance current is smaller than the current value of the first resonance current, and the second resonance mode supports the first frequency band of the preset frequency band range.

2. The foldable electronic device of claim 1, wherein, The first radiator includes a first ground end and a first free end, the first ground end is grounded, the feed point is located between the first ground end and the first free end, and the first ground end is away from the second main body compared with the first free end; The second radiator includes a second ground end and a second free end, the second ground end is grounded, and the second ground end is adjacent to the first free end compared with the second free end; When the foldable electronic device is in a folded state: the second free end is arranged corresponding to the first ground end, the second ground end is arranged corresponding to the first free end, and a coupling gap is formed between the second radiator and the first radiator, in the direction in which the first main body points to the second main body, the size W of the coupling gap satisfies: 0.5mm≤W≤4.0mm.

3. The foldable electronic device of claim 2, wherein, When the first radiator and the second radiator are excited to generate a second resonance mode, the second resonance mode includes a quarter wavelength mode of the second radiator.

4. The foldable electronic device of claim 2, wherein, When the foldable electronic device presents a folded state, the first radiator and the second radiator are excited to support a third resonance mode of the preset frequency band range, wherein the resonance frequency point of the supported resonance frequency band of the third resonance mode is located in the preset frequency band and is smaller than the resonance frequency point corresponding to the second resonance mode.

5. The foldable electronic device of claim 4, wherein, When the first radiator and the second radiator are excited to generate a third resonance mode, the third resonance mode includes a quarter wavelength mode of the first radiator.

6. The foldable electronic device of claim 5, wherein, When the first radiator and the second radiator are excited to support the third resonant mode of the preset frequency range, the first radiator is excited to generate a third resonant current, the second radiator is excited to generate a fourth resonant current opposite to the third resonant current, and a current value of the fourth resonant current is less than a current value of the first resonant current.

7. The electronic device of claim 4, wherein, The foldable electronic device further comprises a floor, and when the foldable electronic device is in the folded state, the antenna assembly further supports a fourth resonant mode, wherein the fourth resonant mode supports a resonant frequency range in the preset frequency range, and the fourth resonant mode is a characteristic mode of the floor.

8. The electronic device of claim 7, wherein, The characteristic mode of the floor corresponds to a resonant current flowing in a length direction of the foldable electronic device, and is a half-wavelength characteristic mode.

9. The foldable electronic device of claim 2, wherein, The first resonant mode is a quarter-wavelength mode of the first radiator.

10. The foldable electronic device of claim 2, wherein, When the foldable electronic device is in the unfolded state, the second ground end is spaced apart from the first free end by a coupling gap, the second radiator is coupled to the first radiator through the coupling gap, the second radiator is excited to support a fifth resonant mode of the preset frequency range, and a resonant frequency point of the fifth resonant mode is less than a resonant frequency point of the first resonant mode.

11. The foldable electronic device of claim 10, wherein, The fifth resonant mode is a quarter-wavelength mode of the second radiator.

12. The foldable electronic device of claim 10, wherein, When the foldable electronic device is in the unfolded state, a size d of the coupling gap in the arrangement direction of the first main body and the second main body satisfies 5mm≤d≤10mm.

13. The foldable electronic device of claim 2, wherein, The antenna assembly further comprises: a first matching circuit, one end of the first matching circuit being electrically connected to the feed point, the other end of the first matching circuit being electrically connected to a feed source, and the first matching circuit being used to adjust an electrical length of the first radiator; and a second matching circuit, one end of the second matching circuit being electrically connected to the second ground end, the other end of the second matching circuit being grounded, and the second matching circuit being used to adjust an electrical length of the second radiator.

14. The foldable electronic device of claim 13, wherein, The matching sub-circuit in the first matching circuit or the matching sub-circuit in the second matching circuit further comprises one or more of the following circuits: a band-pass circuit formed by an inductor and a capacitor in series; a band-stop circuit formed by an inductor and a capacitor in parallel; an inductor, a first capacitor, and a second capacitor, the inductor being connected in parallel with the first capacitor, and the second capacitor being electrically connected to a node at which the inductor and the first capacitor are electrically connected; a capacitor, a first inductor, and a second inductor, the capacitor being connected in parallel with the first inductor, and the second inductor being electrically connected to a node at which the capacitor and the first inductor are electrically connected; an inductor, a first capacitor, and a second capacitor, the inductor being connected in series with the first capacitor, and one end of the second capacitor being electrically connected to a first end of the inductor that is not connected to the first capacitor, and the other end of the second capacitor being electrically connected to one end of the first capacitor that is not connected to the inductor; a capacitor, a first inductor, and a second inductor, the capacitor and the first inductor being connected in series, one end of the second inductor being electrically connected to one end of the capacitor not connected to the first inductor, the other end of the second inductor being electrically connected to one end of the first inductor not connected to the capacitor; a first capacitor, a second capacitor, a first inductor, and a second inductor, the first capacitor and the first inductor being connected in parallel, the second capacitor and the second inductor being connected in parallel, and one end of the second capacitor and the second inductor being electrically connected to one end of the first capacitor and the first inductor; a first capacitor, a second capacitor, a first inductor, and a second inductor, the first capacitor and the first inductor being connected in series to form a first unit, the second capacitor and the second inductor being connected in series to form a second unit, and the first unit and the second unit being connected in parallel.

15. The foldable electronic device of claim 13, wherein, The first matching circuit includes a switch and a matching sub-circuit, the matching sub-circuit and the switch being connected in series to form a series unit, one end of the series unit being electrically connected to the feed point, and the other end of the series unit being grounded. When the foldable electronic device is in the unfolded state, the switch is turned off, and the first radiator is excited to generate a first resonant mode. When the foldable electronic device is in the folded state, the switch is turned on, and the second radiator is excited to generate the first resonant current.

16. The foldable electronic device of claim 1, wherein, The preset frequency range is an LB frequency range, and the first frequency range is an N28 frequency range.

17. The foldable electronic device of claim 1, wherein, The first body and the second body are conductive structures, when the foldable body is in the unfolded state: the first body and the second body are electrically connected, the first body and the second body constitute a radiation arm of a dipole antenna, the other radiation arm of the dipole antenna at least includes the first radiator, and the dipole antenna supports the first frequency range.

18. The foldable electronic device of claim 1, wherein, When the foldable electronic device is in the unfolded state and the antenna assembly supports the first frequency range, the SAR value of the foldable electronic device is a first SAR value. When the foldable electronic device is in the folded state and the antenna assembly supports the first frequency range, the SAR value of the foldable electronic device is a second SAR value, and the second SAR value is less than the first SAR value.

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