Foldable electronic device

Abstract

Provided in the present application is a foldable electronic device, comprising a foldable frame and an antenna assembly, wherein a first feed source is electrically connected to a first radiation branch and is used for exciting the first radiation branch to form a first resonant mode that supports a first frequency band; when the foldable electronic device is in a folded state, a second radiation branch and the first radiation branch are at least partially opposite each other in a folding thickness direction and form a first coupling gap, and the second radiation branch forms, under the coupling of the first radiation branch, a second resonant mode that supports a second frequency band; and when the foldable electronic device is in the folded state, a third radiation branch and the second radiation branch are at least partially opposite each other in the folding thickness direction and form a second coupling gap, and the third radiation branch forms, under the coupling of the second radiation branch, a third resonant mode that supports a third frequency band. Therefore, the radiation efficiency of the foldable electronic device in the folded state at the first frequency band is improved.

Description

Foldable electronic devices

[0001] This application claims priority to Chinese Patent Application No. 2025104948374, filed on April 19, 2025, entitled "Foldable Electronic Device", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communication technology, and more specifically to a foldable electronic device. Background Technology

[0003] With the development of network technology, the appearance of mobile phones and other electronic devices has evolved into various forms such as foldable, candybar, and flip phones. The ever-increasing pursuit of higher screen-to-body ratios has severely limited the space available for antenna design. However, for foldable electronic devices, the metal reference ground changes when the phone is folded, potentially causing the antenna's radiation performance to deteriorate or even malfunction due to the altered antenna environment. Therefore, improving the antenna radiation performance of foldable electronic devices after folding has become a crucial technical challenge. Summary of the Invention

[0004] This application provides a foldable electronic device that improves the antenna radiation performance when folded.

[0005] In a first aspect, this application provides a foldable electronic device, comprising:

[0006] A foldable frame includes a first side frame and a second side frame that are arranged opposite to each other. When the foldable frame is in a folded state, the first side frame and the second side frame are arranged opposite to each other in the folding thickness direction.

[0007] Antenna assembly, the antenna assembly comprising:

[0008] The first radial branch is located on the first side frame;

[0009] A first feed source, electrically connected to the first radiating stub, is used to excite the first radiating stub to form a first resonant mode supporting the first frequency band.

[0010] The second radiating branch is disposed on the second side frame. When the foldable electronic device is in a folded state, the second radiating branch is at least partially opposite to the first radiating branch in the folding thickness direction and forms a first coupling gap. The second radiating branch forms a second resonant mode supporting the second frequency band under the coupling of the first radiating branch.

[0011] The third radiating branch is disposed on the first side frame and is spaced apart from the first radiating branch along the extension direction of the first side frame. When the foldable electronic device is in a folded state, the third radiating branch and the second radiating branch are at least partially opposite each other in the folding thickness direction and form a second coupling gap. The third radiating branch forms a third resonant mode supporting the third frequency band under the coupling of the second radiating branch.

[0012] Secondly, this application provides a foldable electronic device, including a foldable frame, a first ground plane, a second ground plane, and an antenna assembly. The foldable frame includes a first side frame and a second side frame disposed opposite to each other. When the foldable frame is in a folded state, the first side frame and the second side frame are disposed opposite to each other in the folding thickness direction. The first ground plane and the second ground plane are movably connected to each other to be in a folded state or an unfolded state. The antenna assembly includes a first radiating stub, a first feed, and a second radiating stub. The first radiating stub is disposed on the first side frame and along the first ground plane. The first radiating stub includes a first grounding point and a first feed point. The device includes an electrical point and a first open end; a first feed source is electrically connected to the first feed point to excite the first radiating stub to form a first resonant mode supporting the first frequency band; a second radiating stub is disposed on the second side frame and along the second floor, the second radiating stub including a second open end and a third open end. When the foldable electronic device is in a folded state, the second radiating stub and the first radiating stub are at least partially opposite in the folding thickness direction and form a first coupling gap, the first open end and the second open end are adjacent to and coupled; the second radiating stub forms a second resonant mode supporting the second frequency band under the coupling of the first radiating stub. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below.

[0014] Figure 1 is a three-dimensional structural diagram of a foldable electronic device in its unfolded state according to an embodiment of this application;

[0015] Figure 2 is a three-dimensional structural diagram of a foldable electronic device in a folded state according to an embodiment of this application;

[0016] Figure 3 is a top view of the rear cover of a foldable electronic device in its unfolded state, according to Embodiment 1 of this application.

[0017] Figure 4 is a schematic diagram of the current distribution of a foldable electronic device in a folded state according to Embodiment 1 of this application;

[0018] Figure 5 is a top view of the rear cover side of a foldable electronic device in the unfolded state, according to Embodiment 1 of this application.

[0019] Figure 6 is a schematic diagram of the current distribution of a foldable electronic device provided in Embodiment 1 of this application when it is pulled apart to a certain distance in a folded state;

[0020] Figure 7 is the S-parameter curve of an antenna assembly of a foldable electronic device provided in Embodiment 1 of this application;

[0021] Figure 8 is a top view of the rear cover side of a foldable electronic device in the unfolded state according to Embodiment 2 of this application;

[0022] Figure 9 is a top view of the rear cover side of a foldable electronic device in the unfolded state according to Embodiment 2 of this application.

[0023] Figure 10 is a schematic diagram of the current distribution of a foldable electronic device in a folded state according to Embodiment 2 of this application;

[0024] Figure 11 is a schematic diagram of the current distribution of a foldable electronic device provided in Embodiment 2 of this application when it is pulled apart to a certain distance in a folded state;

[0025] Figure 12 is a schematic diagram of the structure of a foldable electronic device including a first switch tuning circuit according to Embodiment 1 of this application;

[0026] Figure 13 is a schematic diagram of the structure of a foldable electronic device including a first switch tuning circuit according to Embodiment 2 of this application;

[0027] Figure 14 is a schematic diagram of the structure of a foldable electronic device including a second switch tuning circuit according to Embodiment 1 of this application;

[0028] Figure 15 is a schematic diagram of the structure of a foldable electronic device including a second switching tuning circuit according to Embodiment 2 of this application;

[0029] Figure 16 is a schematic diagram of the structure of a foldable electronic device including a third switch tuning circuit according to Embodiment 1 of this application;

[0030] Figure 17 is a schematic diagram of the structure of a foldable electronic device including a third switch tuning circuit according to Embodiment 2 of this application;

[0031] Figure 18 is a structural schematic diagram of a foldable electronic device including a first switching unit and a second feed source provided in Embodiment 2 of this application;

[0032] Figure 19 is a schematic diagram of a foldable electronic device including a second switching unit and a third feed source according to Embodiment 2 of this application;

[0033] Figure 20 is a schematic diagram of the unfolded state of a foldable electronic device provided in Embodiment 3 of this application;

[0034] Figure 21 is a schematic diagram of the structure of a foldable electronic device in a folded state according to Embodiment 3 of this application;

[0035] Figure 22 is a second structural schematic diagram of a foldable electronic device in its unfolded state according to Embodiment 3 of this application;

[0036] Figure 23 is a schematic diagram of the structure of a foldable electronic device in a folded state according to Embodiment 3 of this application;

[0037] Figure 24 shows the efficiency curves of the first feed excitation separately set first radiating branch in the unfolded and folded states provided in this application.

[0038] Figure 25 shows the S-parameter curves of the foldable electronic device with a second radiating branch and a first radiating branch provided in Embodiment 1 of this application in the unfolded state and the folded state.

[0039] Figure 26 shows the efficiency curves of the foldable electronic device with a second radiating branch and a first radiating branch provided in Embodiment 1 of this application in the unfolded state and the folded state.

[0040] Figure 27 shows the efficiency curves of the foldable electronic device provided in Embodiment 1 of this application, which has a second radiating branch, a first radiating branch, and a third radiating branch, in the unfolded state and the folded state.

[0041] Figure 28 shows the efficiency curves of the first feed excitation separately set first radiating branch in the unfolded and folded states provided in this application.

[0042] Figure 29 shows the S-parameter curves of the foldable electronic device with a second radiating branch and a first radiating branch provided in Embodiment 2 of this application in the unfolded state and the folded state.

[0043] Figure 30 shows the efficiency curves of the foldable electronic device with a second radiating branch and a first radiating branch provided in Embodiment 2 of this application in the unfolded state and the folded state.

[0044] Figure 31 shows the efficiency curves of the foldable electronic device with a second radiating branch and a first radiating branch provided in Embodiment 2 of this application in the unfolded and folded states. Detailed Implementation

[0045] The technical solution of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the embodiments described in this application are only a part of the embodiments, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application without creative effort are within the protection scope of this application.

[0046] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment to other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0047] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a particular order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, an assembly or device comprising one or more components is not limited to the one or more components listed, but may optionally also include one or more components not listed but inherent to the exemplified product, or one or more components that it should have based on the described function.

[0048] Please refer to Figure 1, which is a structural schematic diagram of a foldable electronic device 1000 provided in Embodiment 1 of this application. The foldable electronic device 1000 includes, but is not limited to, foldable mobile phones, foldable tablets, foldable laptops, foldable computers, foldable wearable devices, and other devices with communication functions. This embodiment of the application uses a foldable mobile phone as an example for illustration; other foldable electronic devices 1000 can refer to this embodiment.

[0049] Please refer to Figures 1 and 2. Figure 2 is a schematic diagram of the structure of an electronic device provided in Embodiment 1 of this application. The foldable electronic device 1000 includes a first main body 710 and a second main body 720. The first main body 710 and the second main body 720 are movably connected (including a rotating connection or a sliding connection), and the state between the first main body 710 and the second main body 720 includes a folded state and an unfolded state. When the foldable electronic device 1000 is in the folded state, the first main body 710 and the second main body 720 are stacked along the thickness direction of the foldable electronic device 1000 to form a relatively small planar area, which is convenient for carrying and small-screen display, etc. When the foldable electronic device 1000 is in the unfolded state, the first main body 710 and the second main body 720 unfold each other to form a relatively large planar area, which is convenient for large-screen display, etc.

[0050] Please refer to Figures 1 and 2. The following embodiment uses the rotational connection between the first body 710 and the second body 720 via a pivot 730 as an example. For ease of explanation, in the unfolded state, the thickness direction of the foldable electronic device 1000 is defined as the Z direction, the width direction as the X direction, and the length direction as the Y direction.

[0051] Optionally, please refer to Figures 1 and 2. When the foldable electronic device 1000 is a large foldable screen, the hinge 730 can be set along the Y direction, and the first main body 710, the hinge 730 and the second main body 720 are connected in sequence along the X direction.

[0052] Optionally, when the foldable electronic device 1000 is a small foldable screen, the hinge 730 can be set along the X direction, and the first main body 710, the hinge 730 and the second main body 720 are connected in sequence along the Y direction.

[0053] Optionally, the number of hinges 730 can be one or more; in other words, the foldable electronic device 1000 can be a bi-fold screen, a tri-fold screen, or a quad-fold screen, etc.

[0054] The following embodiments use a foldable electronic device 1000 with a large foldable screen as an example for illustration.

[0055] Referring to Figure 3, the foldable electronic device 1000 includes a foldable frame 300. The foldable frame 300 includes a first frame 301 and a second frame 302. The first frame 301 is located in the first main body 710, and the second frame 302 is located in the second main body 720. The first frame 301 includes a first top frame 321a, a first side frame 322, and a first bottom frame 324a connected in sequence. The second frame 302 includes a second top frame 321b, a second side frame 323, and a second bottom frame 324b connected in sequence. The first side frame 322 and the second side frame 323 are arranged opposite to each other. When the foldable frame 300 is folded, the first side frame 322 and the second side frame 323 are arranged opposite to each other in the folding thickness direction.

[0056] Please refer to Figure 3. The first top frame 321a and the second top frame 321b are rotatably connected to both sides of the pivot 730. When the foldable electronic device 1000 is in the folded state, the first top frame 321a and the second top frame 321b are arranged opposite each other and spaced apart along the thickness direction of the foldable electronic device 1000. When the foldable electronic device 1000 is in the unfolded state, the first top frame 321a and the second top frame 321b are arranged collinearly.

[0057] Please refer to Figure 3. The first bottom frame 324a and the second bottom frame 324b are rotatably connected to both sides of the pivot 730. When the foldable electronic device 1000 is in the folded state, the first bottom frame 324a and the second bottom frame 324b are arranged opposite each other and spaced apart along the thickness direction of the foldable electronic device 1000. When the foldable electronic device 1000 is in the unfolded state, the first bottom frame 324a and the second bottom frame 324b are arranged collinearly.

[0058] Please refer to Figure 3. The extension directions of the first side frame 322 and the second side frame 323 are both parallel to the length direction Y of the foldable electronic device 1000.

[0059] Optionally, the first top border 321a is a straight border, and the first side border 322 and the second side border 323 both have straight borders in the middle and curved borders at both ends. The bending angles of the curved borders at both ends of the first side border 322 are close to or equal to 90°. The bending angles of the curved borders at both ends of the second side border 323 are also close to or equal to 90°. The curved borders are rounded. The first bottom border 324a is a straight border.

[0060] Please refer to Figure 3. The reference floor 500 includes a first floor 510 and a second floor 520. The first floor 510 and the second floor 520 are movably connected to each other to be in a folded or unfolded state.

[0061] Referring to Figure 3, a first top frame 321a, a first side frame 322, a first bottom frame 324a, and a pivot 730 are arranged around the periphery of the first floor 510. A second top frame 321b, a second side frame 323, a second bottom frame 324b, and a pivot 730 are arranged around the periphery of the second floor 520. The second floor 520 is movably connected to the first floor 510. Furthermore, the first floor 510 and the second floor 520 are rotatably connected via the pivot 730.

[0062] Because various slots and holes are formed on the reference ground edge of the first ground plane 510 as needed to accommodate components or avoid other structures within the mobile phone, the first ground plane 510 includes, but is not limited to, the metal alloy portion within the foldable frame 300 and the reference ground metal portion of the circuit board. These metal portions form a whole and serve as a reference ground. Roughly speaking, the first ground plane 510 in the electronic device 1000 can be equivalent to a roughly rectangular shape. The second ground plane 520 includes, but is not limited to, the metal alloy portion within the foldable frame 300 and the reference ground metal portion of the circuit board. These metal portions form a whole and serve as a reference ground. Roughly speaking, the second ground plane 520 in the electronic device 1000 can be equivalent to a roughly rectangular shape.

[0063] Optionally, referring to Figure 3, the first floor 510 and the second floor 520 are in an unfolded state when the foldable electronic device 1000 is in an unfolded state. The first floor 510 and the second floor 520 are in a folded state when the foldable electronic device 1000 is in a folded state.

[0064] Please refer to Figure 3. The edge of the first floor 510 includes the first floor top edge 511, the first floor side edge 512 and the first floor bottom edge 513 connected in sequence.

[0065] Referring to Figure 3, the edge of the second floor 520 includes a second floor top edge 521, a second floor side edge 522, and a second floor bottom edge 523 connected sequentially. The first floor top edge 511 is adjacent to (e.g., opposite to) the first top frame 321a, the first floor side edge 512 is adjacent to the first side frame 322, and the first floor bottom edge 513 is adjacent to the first bottom frame 324a. The second floor top edge 521 is adjacent to the second top frame 321b, the second floor side edge 522 is adjacent to the second side frame 323, and the second floor bottom edge 523 is adjacent to the second bottom frame 324b.

[0066] Let's take electronic device 1000 as an example to illustrate the working environment of a mobile phone.

[0067] Optionally, referring to Figure 1, the foldable electronic device 1000 also includes a foldable screen 210, which is disposed on one side of the foldable frame 300 in the thickness direction. Specifically, the top edge of the foldable screen 210 is connected to or adjacent to the first top frame 321a and the second top frame 321b of the foldable frame 300. The first side edge of the foldable screen 210 is connected to or adjacent to the first side frame 322 of the foldable frame 300. The bottom edge of the foldable screen 210 is connected to or adjacent to the first bottom frame 324a and the second bottom frame 324b of the foldable frame 300. The second side edge of the foldable screen 210 is connected to or adjacent to the second side frame 323 of the foldable frame 300.

[0068] The foldable screen 210 folds as the foldable frame 300 folds, and unfolds as the foldable frame 300 unfolds.

[0069] In one alternative embodiment, referring to FIG2, the foldable electronic device 1000 further includes a secondary screen 220. The secondary screen 220 is disposed on the opposite side of the foldable frame 300 in the thickness direction.

[0070] In one optional embodiment, the area of ​​the secondary screen 220 is approximately the same as the area of ​​the foldable screen 210 in its folded state. The secondary screen 220 is positioned opposite to a portion of the foldable screen 210. Specifically, the top edge of the foldable screen 210 is connected to or adjacent to the second top edge 321b of the foldable frame 300. The first side edge of the foldable screen 210 is adjacent to or connected to the hinge. The bottom edge of the foldable screen 210 is connected to or adjacent to the second bottom edge 324b of the foldable frame 300. The second side edge of the foldable screen 210 is connected to or adjacent to the second side edge 323 of the foldable frame 300.

[0071] Referring to Figure 2, the foldable electronic device 1000 also includes a back cover 400. Specifically, the back cover 400 is positioned opposite to the folding screen 210. When the foldable electronic device 1000 is in the unfolded state, the back cover 400 and the secondary screen 220 unfold relative to each other.

[0072] The top edge of the back cover 400 is connected to or adjacent to the first top edge 321a of the foldable frame 300. The second side edge of the back cover 400 is adjacent to or connected to the hinge. The bottom edge of the back cover 400 is connected to or adjacent to the second bottom edge 324b of the foldable frame 300. The first side edge of the back cover 400 is connected to or adjacent to the first side edge 322 of the foldable frame 300.

[0073] The foldable screen 210 and the back cover 400 are positioned opposite each other to form a first receiving space, which houses the motherboard, camera module, receiver module, battery, sub-board, and various sensors. The motherboard, battery, and sub-board are arranged sequentially from the first top edge 321a to the first bottom edge 324a.

[0074] Please refer to Figure 3, which shows a foldable electronic device 1000 provided in this application. The foldable electronic device 1000 also includes an antenna assembly 100.

[0075] Please refer to Figure 3. The antenna assembly 100 includes a first radiating stub 11, a first feed 21, a second radiating stub 12, and a third radiating stub 13.

[0076] This application does not specifically limit the material of the first radiating branch 11. Optionally, the material of the first radiating branch 11 is a conductive material, including but not limited to conductive materials such as metals and alloys. This application does not specifically limit the shape of the first radiating branch 11. For example, the shape of the first radiating branch 11 includes but is not limited to strips, sheets, rods, coatings, and films. The first radiating branch 11 shown in Figure 3 is merely an example and does not limit the shape of the first radiating branch 11 provided in this application. In this embodiment, the first radiating branch 11 is always strip-shaped. This application does not limit the extension trajectory of the first radiating branch 11. Optionally, the first radiating branch 11 can extend along a straight line, a curve, or a bend. The first radiating branch 11 described above can be a line of uniform width on its extension trajectory, or it can be a strip of varying width, such as one with a gradually changing width or a widened area.

[0077] This application does not specifically limit the form of the first radiating segment 11. Optionally, the form of the first radiating segment 11 includes, but is not limited to, a metal frame, a metal frame embedded in a plastic frame, a metal structure located inside or on the surface of the frame, a flexible circuit board antenna formed on a flexible printed circuit board (FPC), a laser-directly formed antenna (LDS), a printed-directly formed antenna (PDS), a conductive sheet antenna (e.g., a metal bracket antenna), etc. In this embodiment, the first radiating segment 11 is taken as part of the metal frame of the foldable electronic device 1000.

[0078] Referring to Figure 3, the first radiating branch 11 is disposed on the first side frame 322. For example, the first radiating branch 11 is a metal segment of the first side frame 322. Further, the first radiating branch 11 is disposed along the first floor 510. For example, the first radiating branch 11 is adjacent to and spaced apart from the first floor side 512 of the first floor 510.

[0079] Please refer to Figure 3. The first feed source 21 is electrically connected to the first radiating branch 11. The first feed source 21 includes, but is not limited to, RF transceiver chips and RF front-end modules. The first feed source 21 can be located on the motherboard.

[0080] Please refer to Figure 3. The first radiating branch 11 includes a first feed point A, which is a small protrusion on the inner side of the first radiating branch 11.

[0081] In this application, the electrical connection between the first feed source 21 and the first radiating branch 11 includes a direct electrical connection between the two structures, or an indirect electrical connection through other components. In this embodiment, the first feed source 21 and the first radiating branch 11 are indirectly electrically connected through radio frequency transmission lines, feed springs, etc.

[0082] Optionally, referring to Figures 3 and 4, the antenna assembly 100 includes a matching circuit M1. The matching circuit M1 is electrically connected between the first feed 21 and the first feed point A. The matching circuit M1 includes at least one of a capacitor and an inductor, and is used to tune the impedance matching between the port of the first feed 21 and the port of the first radiating stub 11.

[0083] Specifically, please refer to Figures 3 and 4. The first feed 21 is capable of providing at least a radio frequency excitation signal for the first frequency band. The first feed 21 is used to excite a first resonant mode supporting the first frequency band to be formed on the first radiating stub 11. The first resonant mode forms a first resonant current I1 on the first radiating stub 11.

[0084] This application does not specifically limit the size of the first frequency band. Optionally, the first frequency band may include, but is not limited to, at least one of the following: LB band (less than 1 GHz), MHB band (1-3 GHz), UHB band (greater than 3 GHz), Wi-Fi band, GPS band, etc. For example, the first frequency band may be an LB band, such as B28 band, B5 band, B8 band, B20 band, or B71 band, etc.

[0085] Please refer to Figures 3 and 4. The second radial branch 12 is located on the second side frame 323.

[0086] The second radiating branch 12 is made of the same material as the first radiating branch 11. The second radiating branch 12 may be a part of the second side frame 323. For example, the second radiating branch 12 is a metal segment of the second side frame 323. Further, the second radiating branch 12 is disposed along the second floor 520. For example, the second radiating branch 12 is adjacent to and spaced apart from the second floor side 522 of the second floor 520.

[0087] Referring to Figures 3 and 4, when the foldable electronic device 1000 is in a folded state, the second radiating stub 12 and the first radiating stub 11 are at least partially opposite each other in the fold thickness direction (Z direction) and form a first coupling gap G1. The second radiating stub 12, coupled with the first radiating stub 11, forms a second resonant mode supporting a second frequency band. The second resonant mode generates a second resonant current I2 on the second radiating stub 12.

[0088] This application does not specifically limit the size of the second frequency band. Optionally, the second frequency band may include, but is not limited to, at least one of the following: LB band (less than 1 GHz), MHB band (1-3 GHz), UHB band (greater than 3 GHz), Wi-Fi band, GPS band, etc.

[0089] Specifically, when the foldable electronic device 1000 is in a folded state, the foldable screen 210 is in an inward folded state. The first side frame 322 and the second side frame 323 are directly opposite each other in the thickness direction and have a small gap. This small gap is less than or equal to 3mm, for example, 3mm, or 2mm, or 1.8mm, or 1.6mm, or 1.5mm, or 1.4mm, or 1.2mm, or 1mm, or 0.8mm, or 0.5mm, or 0.4mm, or 0.2mm, or 0.1mm.

[0090] Please refer to Figures 3 and 4. The orthographic projection area of ​​the second radial branch 12 in the fold thickness direction (Z direction) at least partially overlaps with the orthographic projection area of ​​the first radial branch 11 in the fold thickness direction (Z direction). The second radial branch 12 and the first radial branch 11 at least partially form a first coupling gap G1 along the Y direction in the fold thickness direction (Z direction).

[0091] The longer the second radial branch 12 is directly opposite the first radial branch 11 in the fold thickness direction (Z direction), the longer the length of the first coupling gap G1 in the Y direction, and the stronger the coupling strength between the first radial branch 11 and the second radial branch 12.

[0092] Specifically, a first resonant current I1 is formed on the first radiating branch 11, and a coupled electric field is formed in the first coupling gap G1 between the first radiating branch 11 and the second radiating branch 12. The longer the second radiating branch 12 is directly opposite the first radiating branch 11 in the fold thickness direction (Z direction), the stronger the coupled electric field between the first radiating branch 11 and the second radiating branch 12, the stronger the coupling strength between the first radiating branch 11 and the second radiating branch 12, and the stronger the second resonant current I2 formed by the second radiating branch 12 under the coupling of the first radiating branch 11.

[0093] Please refer to Figures 3 and 4. The third radiating branch 13 is located on the first side frame 322.

[0094] The third radiating branch 13 is made of the same material as the first radiating branch 11. The third radiating branch 13 may be a part of the first side frame 322. For example, the third radiating branch 13 is a metal segment of the first side frame 322. The third radiating branch 13 and the first radiating branch 11 are spaced apart along the extending direction of the first side frame 322. Further, the third radiating branch 13 is disposed along the first floor 510. For example, the third radiating branch 13 is adjacent to and spaced apart from the first floor side 512 of the first floor 510.

[0095] Optionally, referring to Figure 5, other radiating branches may be provided between the third radiating branch 13 and the first radiating branch 11. For example, the antenna assembly 100 may also include a fourth radiating branch 14 and a fourth feed 24. The fourth feed 24 includes, but is not limited to, RF transceiver chips and RF front-end modules. The fourth feed 24 may be located on the motherboard. The fourth feed 24 can excite the fourth radiating branch 14 to form a fourth resonant mode supporting the fourth frequency band. In this way, the electronic device can support the first frequency band, the fourth frequency band, etc.

[0096] This application does not specifically limit the size of the fourth frequency band. Optionally, the fourth frequency band may include, but is not limited to, at least one of the following: LB band (less than 1 GHz), MHB band (1-3 GHz), UHB band (greater than 3 GHz), Wi-Fi band, GPS band, etc.

[0097] Referring to Figures 3 and 4, when the foldable electronic device 1000 is in a folded state, the third radiating stub 13 and the second radiating stub 12 are at least partially opposite each other in the fold thickness direction and form a second coupling gap. The third radiating stub 13, coupled with the second radiating stub 12, forms a third resonant mode supporting a third frequency band. The third resonant mode generates a third resonant current I3 on ​​the third radiating stub 13.

[0098] This application does not specifically limit the size of the third frequency band. Optionally, the third frequency band may include, but is not limited to, at least one of the following: LB band (less than 1 GHz), MHB band (1-3 GHz), UHB band (greater than 3 GHz), Wi-Fi band, GPS band, etc.

[0099] Please refer to Figures 3 and 4. The orthographic projection region of the second radial branch 12 in the fold thickness direction (Z direction) at least partially overlaps with the orthographic projection region of the third radial branch 13 in the fold thickness direction (Z direction). The second radial branch 12 and the third radial branch 13 at least partially form a second coupling gap G2 along the Y direction in the fold thickness direction (Z direction).

[0100] The longer the second radial branch 12 and the third radial branch 13 are directly opposite each other in the fold thickness direction (Z direction), the longer the length of the second coupling gap G2 in the Y direction, and the stronger the coupling strength between the third radial branch 13 and the second radial branch 12.

[0101] Specifically, a second resonant current I2 is formed on the second radiating branch 12, and a coupled electric field is formed in the second coupling gap G2 between the third radiating branch 13 and the second radiating branch 12. The longer the second radiating branch 12 and the third radiating branch 13 are directly opposite each other in the fold thickness direction (Z direction), the stronger the coupled electric field between the second radiating branch 12 and the third radiating branch 13, the stronger the coupling strength between the second radiating branch 12 and the third radiating branch 13, and the stronger the third resonant current I3 formed by the third radiating branch 13 under the coupling of the second radiating branch 12.

[0102] The foldable electronic device 1000 provided in this application includes a foldable frame 300 and an antenna assembly 100. The foldable frame 300 includes a first side frame 322 and a second side frame 323 disposed opposite to each other. When the foldable frame 300 is in a folded state, the first side frame 322 and the second side frame 323 are disposed opposite to each other in the folding thickness direction. A first radiating branch 11 is disposed on the first side frame 322. A first feed 21 is electrically connected to the first radiating branch 11 to excite the first radiating branch 11 to form a first resonant mode supporting a first frequency band. A second radiating branch 12 is disposed on the second side frame 323. When the foldable electronic device 1000 is in a folded state, the second radiating branch 12 and the first radiating branch 11 are at least partially opposite to each other in the folding thickness direction and form a first coupling gap G1. The second radiating branch 12 is coupled to the first radiating branch 11. The foldable electronic device 1000 forms a second resonant mode supporting the second frequency band when folded. A third radiating branch 13 is disposed on the first side frame 322, and the third radiating branch 13 is spaced apart from the first radiating branch 11. When the foldable electronic device 1000 is in a folded state, the third radiating branch 13 and the second radiating branch 12 are at least partially opposite each other in the folding thickness direction and form a second coupling gap G2. The third radiating branch 13 forms a third resonant mode supporting the third frequency band under the coupling of the second radiating branch 12. By fully exciting multiple radiating branches (first radiating branch 11, second radiating branch 12 and third radiating branch 13) to form a resonant mode when the foldable electronic device 1000 is in a folded state, a resonant current is generated on multiple radiating branches, increasing the radiation aperture and improving the radiation efficiency of the first frequency band of the foldable electronic device 1000 in the folded state.

[0103] The technicians of this application also discovered in their research that, since the second radiating branch 12 is close to the sub-screen 220, some of the electromagnetic energy on the second radiating branch 12 may be absorbed by the sub-screen 220 (which has a metal plate, etc.), resulting in some electromagnetic energy being wasted.

[0104] Based on this, the foldable electronic device 1000 provided in this application, by setting a third radiating branch 13, and when the foldable electronic device 1000 is in a folded state, the third radiating branch 13 and the second radiating branch 12 are at least partially opposite each other in the folding thickness direction and form a second coupling gap G2. The third radiating branch 13 forms a third resonant mode supporting the third frequency band under the coupling of the second radiating branch 12. The third radiating branch 13 can couple part of the electromagnetic energy on the second radiating branch 12 to the side where the first side frame 322 is located, thereby moving it relatively away from the sub-screen 220, so as to reduce the absorption of electromagnetic energy by the sub-screen 220 and enable more electromagnetic energy to participate in radiation. The third radiating branch 13 can not only couple part of the electromagnetic energy to the side where the first side frame 322 is located, but also increase the radiation aperture to improve the radiation efficiency of the first frequency band of the foldable electronic device 1000 in the folded state.

[0105] Referring to Figure 3, in the deployed state, the first radiating stub 11 generates a first resonant current I1 supporting the first frequency band under the excitation of the first feed source 21. Simultaneously, in the first resonant mode, a ground current distribution is formed on the first ground plate 510 along the first side frame 322 (along the Y direction). At this time, the ground current distribution on the first ground plate 510 is located in the region of the first ground plate 510 directly opposite the first radiating stub 11 in the X direction, and there is essentially no ground current along the Y direction on the second ground plate 520.

[0106] Referring to Figure 6, in the folded state, the first radiating stub 11 generates a first resonant current I1 supporting the first frequency band under the excitation of the first feed source 21. Simultaneously, in the first resonant mode, a first ground current distribution Q1 is formed on the first ground 510 along the first side frame 322 (along the Y direction). At this time, the first ground current distribution Q1 is located in a first region of the first ground 510, which is directly opposite the first radiating stub 11 in the X direction.

[0107] In Figure 6, the first main body 710 and the second main body 720 are in a folded state. To observe the current distribution on the first floor 510 and the second floor 520, the first main body 710 and the second main body 720 are pulled apart by a certain distance.

[0108] Referring to Figure 6, in the folded state and the second resonant mode, a second ground current distribution Q2 is formed on the second ground 520 along the second side frame 323 (along the Y direction). The direction of the first ground current distribution Q1 is the same as the direction of the second ground current distribution Q2. At this time, the second ground current distribution Q2 is located in the second region of the second ground 520, and the second region is directly opposite the second radiating branch 12 in the X direction.

[0109] For example, the direction of the first ground current distribution Q1 is upward along the Y direction (towards the first top frame 321a), and the direction of the second ground current distribution Q2 is upward along the Y direction (towards the second top frame 321b).

[0110] This embodiment designs the antenna assembly 100 to include a first radiating stub 11 and a second radiating stub 12, thereby exciting a first ground current distribution Q1 along the Y direction on the first ground plane 510 and a second ground current distribution Q2 along the Y direction on the second ground plane 520. The first ground current distribution Q1 and the second ground current distribution Q2 are in the same direction, meaning that both the first and second regions on the aforementioned reference ground plane have longitudinal currents distributed along the Y direction. The more longitudinal current distributions on the reference ground plane, the larger the radiation capacitance element of the reference ground plane participating in the first frequency band, and the greater the improvement in radiation efficiency for the first frequency band.

[0111] Further, referring to Figure 6, in the folded state, in the third resonant mode, a third ground current distribution Q3 is formed on the first ground 510 along the first side frame 322 (along the Y direction). The direction of the third ground current distribution Q3 is the same as the direction of the first ground current distribution Q1.

[0112] For example, the direction of the first ground current distribution Q1 is upward along the Y direction (towards the first top edge 321a), the direction of the second ground current distribution Q2 is upward along the Y direction (towards the second top edge 321b), and the direction of the third ground current distribution Q3 is upward along the Y direction (towards the first top edge 321a).

[0113] At this point, the third floor current distribution Q3 is located in the third region of the first floor 510, and the third region is directly opposite the third radiating branch 13 in the X direction. The third region and the first region are aligned in the Y direction. In other words, the area of ​​the floor current distribution along the Y direction on the first floor 510 increases.

[0114] This embodiment designs the antenna assembly 100 to include a first radiating stub 11, a second radiating stub 12, and a third radiating stub 13, thereby exciting a first ground current distribution Q1 and a second ground current distribution Q2 along the Y direction on the first ground 510, and exciting a second ground current distribution Q2 along the Y direction on the second ground 520. This better excites the current of the first main board along the Y direction, resulting in a better longitudinal radiation mode. The first ground 510 near the third radiating stub 13 also generates a current in the same direction (e.g., upward along the Y direction), and the longitudinal mode of the reference ground is more fully excited.

[0115] Optionally, referring to Figure 6, the direction of the resonant current in the first resonant mode on the first radiating stub 11 is the same as the direction of the resonant current in the second resonant mode on the second radiating stub 12. The direction of the first resonant current I1 is the same as the direction of the second resonant current I2.

[0116] For example, referring to Figure 6, when the foldable electronic device 1000 is in a folded state, under the excitation of the first feed source 21, a first resonant current I1 is formed on the first radiating stub 11 in the downward direction of the Y direction (towards the first bottom frame 324a), and simultaneously, a first ground current distribution Q1 in the upward direction of the Y direction is formed on the first ground 510. A second resonant current I2 is formed on the second radiating stub 12 in the downward direction of the Y direction (towards the second bottom frame 324b), and simultaneously, a second ground current distribution Q2 in the upward direction of the Y direction is formed on the second ground 520.

[0117] This embodiment designs the resonant current direction of the first resonant mode on the first radiating stub 11 to be the same as the resonant current direction of the second resonant mode on the second radiating stub 12. This ensures that when the foldable electronic device 1000 is in a folded state, both the first radiating stub 11 and the second radiating stub 12 form unidirectional stub currents, thereby increasing the radiation aperture of the first frequency band in the folded state and thus increasing the radiation efficiency of the first frequency band. Simultaneously, it also increases the unidirectional ground current on the second ground plane 520, enhancing the radiation contribution of the reference ground plane in the first frequency band, further improving the radiation efficiency of the first frequency band in the folded state.

[0118] As a further optional step, as shown in Figure 6, the direction of the resonant current in the second resonant mode on the second radiating stub 12 is the same as the direction of the resonant current in the third resonant mode on the third radiating stub 13.

[0119] For example, referring to Figure 6, when the foldable electronic device 1000 is in the folded state, under the excitation of the first feed source 21, a first resonant current I1 is formed on the first radiating stub 11, moving downward in the Y direction (towards the first bottom frame 324a), and simultaneously, a first ground current distribution Q1 is formed on the first ground 510, moving upward in the Y direction. A second resonant current I2 is formed on the second radiating stub 12, moving downward in the Y direction (towards the second bottom frame 324b), and simultaneously, a second ground current distribution Q2 is formed on the second ground 520, moving upward in the Y direction. A third resonant current I3 is formed on the third radiating stub 13, moving downward in the Y direction (towards the first bottom frame 324a), and simultaneously, a second ground current distribution Q2 is formed on the first ground 510, moving upward in the Y direction.

[0120] This embodiment designs the resonant current direction of the first resonant mode on the first radiating branch 11 to be the same as the resonant current direction of the second resonant mode on the second radiating branch 12, and the resonant current direction of the second resonant mode on the second radiating branch 12 to be the same as the resonant current direction of the third resonant mode on the third radiating branch 13. This ensures that when the foldable electronic device 1000 is in a folded state, the first radiating branch 11, the second radiating branch 12, and the third radiating branch 13 all form unidirectional branch currents, further increasing the radiation aperture of the first frequency band in the folded state, thereby increasing the radiation efficiency of the first frequency band. Simultaneously, it also further increases the unidirectional ground current on the first ground plane 510, enhancing the radiation contribution of the reference ground plane in the first frequency band, thus further improving the radiation efficiency of the first frequency band in the folded state.

[0121] As mentioned above, please refer to Figure 7. In the folded state, the first radiating stub 11 forms a first resonant mode supporting the first frequency band under the excitation of the first feed source 21; the second radiating stub 12 forms a second resonant mode supporting the second frequency band under the coupling of the first radiating stub 11; and the third radiating stub 13 forms a third resonant mode supporting the third frequency band under the coupling of the second radiating stub 12. The center frequency of the first frequency band is smaller than the center frequency of the second frequency band. The center frequency of the second frequency band is smaller than the center frequency of the third frequency band.

[0122] In this embodiment, the resonant point of the second resonant mode (the center frequency of the second frequency band) is close to the resonant point of the first resonant mode (the center frequency of the first frequency band), so that the resonant point of the second resonant mode is located on the high-frequency side of the resonant point of the first resonant mode. This facilitates the direction of the first resonant current I1 on the first radiating stub 11 being the same as the direction of the second resonant current I2 on the second radiating stub 12, reducing the reverse current on the radiating stub and improving the radiation efficiency of the first frequency band. It also benefits from the fact that the direction of the first ground current distribution Q1 on the first ground plane 510 is the same as the direction of the second ground current distribution Q2, reducing the directional current of the reference ground plane and improving the radiation efficiency of the first frequency band. For example, the difference between the resonant point of the first resonant mode and the resonant point of the second resonant mode is less than 200MHz. Furthermore, the first and second frequency bands form a continuous frequency band. That is, the first and second frequency bands form a broadband frequency band, which can cover the sub-bands in the LB frequency band, increasing the impedance bandwidth.

[0123] In this embodiment, the resonant point of the third resonant mode (the center frequency of the third frequency band) is close to the resonant point of the second resonant mode (the center frequency of the second frequency band), so that the resonant point of the third resonant mode is located on the high-frequency side of the resonant point of the second resonant mode. This facilitates further increasing the co-directional resonant current on the radiating stubs and further improving the radiation efficiency of the first frequency band. It also further excites the co-directional ground current on the reference ground and further excites the longitudinal current mode on the reference ground. For example, the difference between the resonant point of the second resonant mode and the resonant point of the third resonant mode is less than 200MHz.

[0124] The structure of the first radial branch 11 will be illustrated in detail below with reference to the accompanying drawings.

[0125] Please refer to Figure 3. The first radiating branch 11 includes a first grounding point D1, a first feed point A, and a first open end E1. Specifically, the first grounding point D1, the first feed point A, and the first open end E1 are arranged sequentially. Optionally, the distance between the first feed point A and the first open end E1 is less than the distance between the first feed point A and the first grounding point D1.

[0126] The first grounding point D1 and the first open end E1 are the two ends of the first radial branch 11, respectively. The first grounding point D1 is electrically connected to the first ground plate 510. The electrical connection method includes, but is not limited to, the first grounding point D1 being electrically connected to the first ground plate 510 through a conductive spring, or the first grounding point D1 being interconnected with the first ground plate 510 as a whole.

[0127] Please refer to Figure 3. The second radial branch 12 includes a second open end E2. The second open end E2 is one end of the second radial branch 12.

[0128] Referring to Figure 4, when the foldable electronic device 1000 is in a folded state, the first opening end E1 and the second opening end E2 are adjacent and coupled to each other. Optionally, the distance between the first opening end E1 and the second opening end E2 is less than the distance between the first grounding point D1 and the second opening end E2. Further, the distance between the first opening end E1 and the second opening end E2 is close, so that the first opening end E1 and the second opening end E2 can be coupled to each other.

[0129] Further optionally, referring to Figure 4, the first opening end E1 is directly opposite the second opening end E2 in the thickness direction (Z direction). Generally, the electric field of the first opening end E1 is stronger, and the electric field of the second opening end E2 is stronger. In this embodiment, by placing the first opening end E1 and the second opening end E2 close to or directly opposite each other in the folded state, a stronger coupling is formed between the first radiating branch 11 and the second radiating branch 12. This facilitates the formation of a second resonant mode supporting the second frequency band on the second radiating branch 12, and the formation of a strong second resonant current I2 that is in the same direction as the first resonant current I1 on the second radiating branch 12.

[0130] This application does not limit the position of the first radiating branch 11 on the first side frame 322. Optionally, the first radiating branch 11 is located near the first top frame 321a; or, the first radiating branch 11 is located near the first bottom frame 324a. Optionally, the first opening end E1 is located between the first grounding point D1 and the first top frame 321a; or, the first grounding point D1 is located between the first opening end E1 and the first top frame 321a.

[0131] Please refer to Figure 4. The second radial branch 12 also includes a third open end E3.

[0132] Referring to Figure 4, the third radiating branch 13 also includes a fourth opening end E4. When the foldable electronic device 1000 is in the folded state, the fourth opening end E4 is adjacent to and coupled to the third opening end E3.

[0133] Furthermore, the fourth open end E4 and the third open end E3 are close in distance so that the fourth open end E4 and the third open end E3 can couple with each other.

[0134] Further optionally, referring to Figure 4, the third opening end E3 is directly opposite the fourth opening end E4 in the thickness direction (Z direction). Generally, the electric field of the third opening end E3 is stronger, and the electric field of the fourth opening end E4 is stronger. In this embodiment, by placing the third opening end E3 and the fourth opening end E4 close to or directly opposite each other in the folded state, the third radiating branch 13 and the second radiating branch 12 can form a stronger coupling, which is beneficial for forming a third resonant mode supporting the third frequency band on the third radiating branch 13, and forming a strong third resonant current I3 on ​​the third radiating branch 13 that is in the same direction as the second resonant current I2.

[0135] Referring to Figure 4, the third radiating branch 13 also includes a second grounding point D2. Optionally, the second grounding point D2 and the fourth open end E4 are the two ends of the third radiating branch 13, respectively. The second grounding point D2 is used for electrical connection to the first ground plate 510.

[0136] In one optional embodiment, referring to Figure 4, the second grounding point D2 is located on the side of the fourth open end E4 away from the first grounding point D1. Further optionally, the distance between the fourth open end E4 and the third open end E3 is less than the distance between the second grounding point D2 and the third open end E3.

[0137] Specifically, the first opening E1 is located between the first grounding point D1 and the first top frame 321a. The second grounding point D2 is located near the first bottom frame 324a. When the first ground current distribution Q1 and the third ground current distribution Q3 are formed on the first ground plate 510, since the first radiating branch 11 and the third radiating branch 13 are located relatively close to the first bottom frame 324a, a longitudinal current upward in the Y direction can be excited on the first ground plate 510 from the region near the first bottom frame 324a to the region near the first top frame 321a. Correspondingly, the second radiating branch 12 is located near the second bottom frame 324b, and a longitudinal current upward in the Y direction can be excited on the second ground plate 520 from the region near the second bottom frame 324b to the region near the second top frame 321b. In other words, the first radiating branch 11 and the third radiating branch 13, being relatively close to the first bottom frame 324a, can excite more longitudinal current distributions on the first ground plate 510, fully exciting the longitudinal current mode on the first ground plate 510, and further improving the radiation efficiency of the first frequency band. The second radiating branch 12 is located relatively close to the second bottom frame 324b, which can excite more longitudinal current distribution on the second floor 520, fully excite the longitudinal current mode on the second floor 520, and further improve the radiation efficiency of the first frequency band.

[0138] Optionally, the first frequency band is the LB band. The maximum value of the first frequency band is less than 1 GHz.

[0139] For the LB band, the radiation contribution of the reference floor 500 has a significant effect on improving the radiation performance of the LB band. The larger the longitudinal current distribution area on the reference floor 500, the greater the radiation contribution of the reference floor 500, and the greater the effect on improving the radiation performance of the LB band.

[0140] Further optionally, referring to Figures 8 and 9, the second radial branch 12 also includes a fifth open end E5 and a third grounding point D3. The fifth open end E5 and the third open end E3 are spaced apart. Optionally, the fifth open end E5 and the third open end E3 have a relatively small gap, for example, the gap width between the fifth open end E5 and the third open end E3 is 0 to 2 mm.

[0141] The third grounding point D3 is electrically connected to the second floor 520.

[0142] Please refer to Figures 8 and 9. Define the area between the second open end E2 and the third open end E3 as the first sub-segment 121, and define the area between the fifth open end E5 and the third grounding point D3 as the second sub-segment 122.

[0143] In an optional embodiment, referring to FIG8, the antenna assembly 100 further includes a capacitor element 41. One end of the capacitor element 41 is electrically connected to the third open end E3, and the other end of the capacitor element 41 is electrically connected to the fifth open end E5. The capacitor element 41 is used to enhance the coupling strength between the first sub-stub 121 and the second sub-stub 122 to promote a relatively strong second resonant current I2 distributed on both the first sub-stub 121 and the second sub-stub 122.

[0144] In another alternative embodiment, referring to FIG9, the antenna assembly 100 further includes a conductive element 42. A portion of the conductive element 42 is opposite to and coupled to the third opening end E3, and another portion of the conductive element 42 is opposite to and coupled to the fifth opening end E5. The conductive element 42 includes, but is not limited to, a conductive strip or a conductive plate. For example, the conductive element 42 is a conductive plate. A portion of the conductive element 42 forms a capacitor structure with the end of the first sub-stub 121, and another portion of the conductive element 42 forms a capacitor structure with the end of the second sub-stub 122. The conductive element 42 is used to enhance the coupling strength between the first sub-stub 121 and the second sub-stub 122 to promote a relatively strong second resonant current I2 distributed on both the first sub-stub 121 and the second sub-stub 122.

[0145] For example, referring to Figures 10 and 11, a first gap is also provided on the first side frame 322, adjacent to the first opening end E1. The first gap is formed by opening the first gap on the first side frame 322. A second gap is also provided on the first side frame 322, adjacent to the fourth opening end E4. The second gap is formed by opening the second gap on the first side frame 322. In Figure 11, the first body 710 and the second body 720 are in a folded state. To see the current distribution on the first floor 510 and the second floor 520, the first body 710 and the second body 720 are pulled apart by a certain distance.

[0146] Please refer to Figures 10 and 11. A third gap is also provided on the second side frame 323, which is adjacent to the second open end E2. The third gap is formed by opening the third gap on the second side frame 323. A fourth gap is also provided on the second side frame 323, which is located between the third open end E3 and the fifth open end E5. The fourth gap is formed by opening the fourth gap on the second side frame 323 to form the third open end E3 and the fifth open end E5.

[0147] Optionally, as shown in Figures 10 and 11, in the folded state, the first open end E1 is directly opposite the second open end E2. The third open end E3 is directly opposite the fourth open end E4.

[0148] Further, please refer to Figures 10 and 11. In the folded state, the first gap is directly opposite the third gap, and the second gap is directly opposite the fourth gap.

[0149] The first gap is located near the first radiating branch 11 where the electric field is relatively strong. The third gap is aligned with the first gap during folding so that the third gap can be coupled with the location where the electric field is relatively strong, thereby enhancing the coupling effect between the second radiating branch 12 and the first radiating branch 11.

[0150] The fourth slit is located at a position with a strong electric field on the second radiating branch 12. The fourth slit is aligned with the second slit during folding to facilitate coupling between the second slit and the position with a strong electric field, thereby enhancing the coupling effect between the third radiating branch 13 and the second radiating branch 12.

[0151] Furthermore, in this embodiment, by placing the third radial branch 13 near the first bottom frame 324a and the second radial branch 12 near the second bottom frame 324b, the distance between the second gap and the first bottom frame 324a is relatively large, and the distance between the fourth gap and the second bottom frame is relatively large. Therefore, the first gap and the second gap are not easily gripped by the hand.

[0152] Optionally, the first resonant mode includes a 1 / 4 wavelength mode of the first frequency band. In other words, the electrical length between the first ground point D1 and the first open end E1 is approximately 1 / 4 wavelength of the center frequency of the first frequency band.

[0153] The third resonant mode includes a 1 / 4 wavelength mode of the third frequency band. In other words, the electrical length between the second ground point D2 and the fourth open end E4 is close to 1 / 4 wavelength of the center frequency of the third frequency band. Since the center frequency of the third frequency band is greater than the center frequency of the first frequency band, the electrical length between the second ground point D2 and the fourth open end E4 is less than the electrical length between the second ground point D2 and the fourth open end E4.

[0154] In another alternative embodiment, referring to Figures 3, 4, and 6, the third radiating branch 13 further includes a second grounding point D2. The second grounding point D2 is used for electrical connection to the first floor 510. The second grounding point D2 is located between the fourth opening end E4 and the first grounding point D1.

[0155] The second grounding point D2 is located between the fourth open end E4 and the first grounding point D1. The first grounding point D1 and the second grounding point D2 are spaced apart. Further optionally, the distance between the fourth open end E4 and the third open end E3 is less than the distance between the second grounding point D2 and the third open end E3.

[0156] Specifically, please refer to Figures 3, 4, and 6. The first opening end E1 is located near the first top frame 321a, and the fourth opening end E4 is a certain distance from the first bottom frame 324a. The second opening end E2 is located near the second top frame 321b, and the third opening end E3 is a certain distance from the second bottom frame 324b. Therefore, the first and second gaps are not easily gripped by the hand.

[0157] For example, referring to Figures 3, 4, and 6, a first gap is also provided on the first side frame 322, which is adjacent to the first open end E1. The first gap is formed by opening the first gap on the first side frame 322. A second gap is also provided on the first side frame 322, which is adjacent to the fourth open end E4. The second gap is formed by opening the second gap on the first side frame 322.

[0158] A third gap is also provided on the second side frame 323, which is adjacent to the second open end E2. The third gap is opened on the second side frame 323 to form the second open end E2. A fourth gap is also provided on the second side frame 323, which is adjacent to the third open end E3. The fourth gap is opened on the second side frame 323 to form the third open end E3.

[0159] Optionally, referring to Figures 3, 4, and 6, in the folded state, the first open end E1 and the second open end E2 are directly opposite each other. The third open end E3 and the fourth open end E4 are directly opposite each other. Further, in the folded state, the first slit and the third slit are directly opposite each other, and the second slit and the fourth slit are directly opposite each other.

[0160] The first gap is located near the first radiating branch 11 where the electric field is relatively strong. The third gap is aligned with the first gap during folding so that the third gap can be coupled with the location where the electric field is relatively strong, thereby enhancing the coupling effect between the second radiating branch 12 and the first radiating branch 11.

[0161] The fourth slit is located at a position with a strong electric field on the second radiating branch 12. The fourth slit is aligned with the second slit during folding to facilitate coupling between the second slit and the position with a strong electric field, thereby enhancing the coupling effect between the third radiating branch 13 and the second radiating branch 12.

[0162] Optionally, the first resonant mode includes a 1 / 4 wavelength mode of the first frequency band. In other words, the electrical length between the first ground point D1 and the first open end E1 is approximately 1 / 4 wavelength of the center frequency of the first frequency band.

[0163] Optionally, the second resonant mode includes a half-wavelength mode of the second frequency band. In other words, the electrical length between the second opening end E2 and the third opening end E3 is close to half the wavelength of the center frequency of the second frequency band.

[0164] Optionally, the third resonant mode includes a 1 / 4 wavelength mode of the third frequency band. In other words, the electrical length between the second ground point D2 and the fourth open end E4 is approximately 1 / 4 wavelength of the center frequency of the third frequency band. Since the center frequency of the third frequency band is greater than the center frequency of the first frequency band, the electrical length between the second ground point D2 and the fourth open end E4 is less than the electrical length between the second ground point D2 and the fourth open end E4.

[0165] In a first alternative embodiment of the antenna assembly 100, referring to Figures 12 and 13, the antenna assembly 100 includes a first switching tuning circuit 51. The first switching tuning circuit 51 is electrically connected to a first radiating stub 11. The first switching tuning circuit 51 is used to tune the magnitude of a first frequency band. Further, the first switching tuning circuit 51 is used to tune the center frequency of the first frequency band to be lower than the center frequency of a second frequency band, which facilitates that the direction of the resonant current of the first resonant mode on the first radiating stub 11 is the same as the direction of the resonant current of the second resonant mode on the second radiating stub 12. The first switching tuning circuit 51 includes a first sub-switch 514 and a plurality of first tuning elements 515. One end of the first sub-switch 514 is electrically connected to a first feed point A (or another location on the first radiating stub 11), and the other end of the first sub-switch 514 is optionally electrically connected to one end of one or more first tuning elements 515, with the other end of each first tuning element 515 grounded. The first tuning elements 515 include inductors and / or capacitors, etc.

[0166] Each first tuning element 515 has a different impedance value. The first sub-switch 514 is used to switch different first tuning elements 515 to conduct with the first radiating stub 11, so as to switch the sub-band of the first frequency band.

[0167] For example, the multiple first tuning elements 515 are respectively named first sub-tuning element 211, second sub-tuning element 212, and third sub-tuning element 213. First sub-tuning element 211 is a first inductor. Second sub-tuning element 212 is a second inductor. Third sub-tuning element 213 is a third inductor.

[0168] Optionally, one end of the first inductor is electrically connected to the first selection terminal of the first sub-switch 514, and the other end of the first inductor is grounded. One end of the second inductor is electrically connected to the second selection terminal of the first sub-switch 514, and the other end of the second inductor is grounded. One end of the third inductor is electrically connected to the third selection terminal of the first sub-switch 514, and the other end of the third inductor is grounded.

[0169] When the first sub-switch 514 connects the first radiating stub 11 and the first inductor, the sub-band of the first frequency band supported by the first resonant mode switches to the first sub-LB band, such as the B28 band.

[0170] When the first sub-switch 514 connects the first radiating stub 11 and the second inductor, the sub-band of the first frequency band supported by the first resonant mode switches to the second sub-LB frequency band, such as the B8 frequency band.

[0171] When the first sub-switch 514 conducts the first radiating stub 11 and the third inductor, the sub-band of the first frequency band supported by the first resonant mode switches to the third sub-LB frequency band, such as the B5 frequency band.

[0172] In this embodiment, by setting a first sub-switch 514 and multiple first tuning elements 515, different first tuning elements 515 can be switched to conduct with the first radiating stub 11 through the first sub-switch 514, so as to change the sum of the electrical length of the first radiating stub 11 and the equivalent electrical length of the first tuning element 515, so as to realize the switching support for different frequency bands in a small clearance environment, for example, switching from the B28 frequency band to the B8 frequency band, or switching from the B28 frequency band to the B5 frequency band, etc.

[0173] Optionally, the aforementioned matching circuit M1 includes a first switch tuning circuit 51. That is, one end of the first sub-switch 514 is electrically connected to the first feed point A. In this way, the matching circuit M1 and the first switch tuning circuit 51 share a port to connect to the first radiating branch 11, reducing the number of connection ports provided on the first radiating branch 11, and thus reducing the number of spring contacts.

[0174] In a second alternative embodiment of the antenna assembly 100, as shown in Figures 14 and 15, the antenna assembly 100 includes a second switching tuning circuit 52 electrically connected to a second radiating stub 12. The second switching tuning circuit 52 is used to tune the magnitude of the second frequency band. Further, the second switching tuning circuit 52 is used to tune the center frequency of the second frequency band to be greater than the center frequency of the first frequency band and less than the center frequency of the third frequency band. This facilitates that the resonant current direction of the first resonant mode on the first radiating stub 11 is the same as the resonant current direction of the second resonant mode on the second radiating stub 12, and the resonant current direction of the second resonant mode on the second radiating stub 12 is the same as the resonant current direction of the third resonant mode on the third radiating stub 13. Specifically, the second radiating stub 12 includes a first connection point H1, which is close to the second opening end E2. The second switching tuning circuit 52 is electrically connected to the first connection point H1. The first connection point H1 is located at the current weakness of the second radiating stub 12 in the second resonant mode, so as to facilitate tuning of the equivalent electrical length of the second radiating stub 12.

[0175] Please refer to Figures 14 and 15. The second switching tuning circuit 52 includes a second sub-switch 524 and a plurality of second tuning elements 525. One end of the second sub-switch 524 is electrically connected to the first connection point H1, and the other end of the second sub-switch 524 is optionally electrically connected to one end of one or more second tuning elements 525. The other end of the second tuning element 525 is grounded. The second tuning element 525 includes inductors and / or capacitors, etc.

[0176] Each second tuning element 525 has a different impedance value. The second sub-switch 524 is used to switch different second tuning elements 525 to conduct with the second radiating stub 12, thereby switching the sub-band of the second frequency band.

[0177] For example, the multiple second tuning elements 525 are named the fourth sub-tuning element, the fifth sub-tuning element, and the sixth sub-tuning element, respectively. The fourth sub-tuning element is the fourth inductor. The fifth sub-tuning element is the fifth inductor. The sixth sub-tuning element is the sixth inductor.

[0178] Optionally, one end of the fourth inductor is electrically connected to the first selection terminal of the second sub-switch 524, and the other end of the fourth inductor is grounded. One end of the fifth inductor is electrically connected to the second selection terminal of the second sub-switch 524, and the other end of the fifth inductor is grounded. One end of the sixth inductor is electrically connected to the third selection terminal of the second sub-switch 524, and the other end of the sixth inductor is grounded.

[0179] When the first sub-switch 514 connects the first radiating stub 11 and the first inductor, and the second sub-switch 524 connects the second radiating stub 12 and the fourth inductor, the sub-band of the first frequency band supported by the first resonant mode switches to the B28 frequency band, and the sub-band of the second frequency band supported by the second resonant mode switches to the high-frequency side of the B28 frequency band. This is beneficial because the direction of the resonant current in the first radiating stub 11 of the first resonant mode is the same as the direction of the resonant current in the second radiating stub 12 of the second resonant mode. The second resonant mode is used to improve the radiation efficiency of the first frequency band.

[0180] When the first sub-switch 514 connects the first radiating stub 11 and the second inductor, and the second sub-switch 524 connects the second radiating stub 12 and the fifth inductor, the sub-band of the first frequency band supported by the first resonant mode switches to the B8 frequency band, and the sub-band of the second frequency band supported by the second resonant mode switches to the high-frequency side of the B8 frequency band. This is beneficial because the direction of the resonant current in the first radiating stub 11 of the first resonant mode is the same as the direction of the resonant current in the second radiating stub 12 of the second resonant mode. The second resonant mode is used to improve the radiation efficiency of the first frequency band.

[0181] When the first sub-switch 514 connects the first radiating stub 11 and the third inductor, and the second sub-switch 524 connects the second radiating stub 12 and the sixth inductor, the sub-band of the first frequency band supported by the first resonant mode switches to the B5 frequency band, and the sub-band of the second frequency band supported by the second resonant mode switches to the high-frequency side of the B5 frequency band. This is beneficial because the direction of the resonant current in the first radiating stub 11 of the first resonant mode is the same as the direction of the resonant current in the second radiating stub 12 of the second resonant mode. The second resonant mode is used to improve the radiation efficiency of the first frequency band.

[0182] In this embodiment, by setting a first sub-switch 514 to switch different first tuning elements 515 and first radiating branches 11 to conduct, the sum of the electrical length of the first radiating branch 11 and the equivalent electrical length of the first tuning element 515 is changed; by setting a second sub-switch 524 to switch different second tuning elements 525 and second radiating branches 12 to conduct, the sum of the electrical length of the second radiating branch 12 and the equivalent electrical length of the second tuning element 525 is changed, so as to realize the switching support for different frequency bands in a small clearance environment, for example, switching from the B28 frequency band to the B8 frequency band, or switching from the B28 frequency band to the B5 frequency band, etc.

[0183] In a third alternative embodiment of the antenna assembly 100, referring to Figures 16 and 17, the antenna assembly 100 includes a third switching tuning circuit 53 electrically connected to a third radiating stub 13. The third switching tuning circuit 53 is used to tune the magnitude of the third frequency band. The third switching tuning circuit 53 is electrically connected to the third radiating stub 13, and is used to tune the center frequency of the third frequency band to be greater than the center frequency of the second frequency band, which is beneficial because the direction of the resonant current of the second resonant mode on the second radiating stub 12 is the same as the direction of the resonant current of the third resonant mode on the third radiating stub 13.

[0184] Specifically, please refer to Figures 16 and 17. The third radiating stub 13 includes a second connection point H2, which is close to the fourth open end E4. The third switching tuning circuit 53 is electrically connected to the second connection point H2. The second connection point H2 is located at the current weakness of the third radiating stub 13 in the third resonant mode, so as to facilitate tuning of the equivalent electrical length of the third radiating stub 13.

[0185] Please refer to Figures 16 and 17. The third switching tuning circuit 53 includes a third sub-switch 531 and multiple third tuning elements 532. One end of the third sub-switch 531 is electrically connected to the second connection point H2. The other end of the third sub-switch 531 is optionally electrically connected to one or more ends of the third tuning elements 532. The other end of the third tuning elements 532 is grounded. The third tuning elements 532 include inductors and / or capacitors, etc.

[0186] Each third tuning element 532 has a different impedance value. The third sub-switch 531 is used to switch different third tuning elements 532 and the third radiating stub 13 to conduct, thereby switching the sub-band of the third frequency band.

[0187] For example, the multiple third tuning elements 532 are named the seventh sub-tuning element, the eighth sub-tuning element, and the ninth sub-tuning element, respectively. The seventh sub-tuning element is the seventh inductor. The eighth sub-tuning element is the eighth inductor. The ninth sub-tuning element is the ninth inductor.

[0188] Optionally, one end of the seventh inductor is electrically connected to the first selection terminal of the third sub-switch 531, and the other end of the seventh inductor is grounded. One end of the eighth inductor is electrically connected to the second selection terminal of the third sub-switch 531, and the other end of the eighth inductor is grounded. One end of the ninth inductor is electrically connected to the third selection terminal of the third sub-switch 531, and the other end of the ninth inductor is grounded.

[0189] When the first sub-switch 514 connects the first radiating stub 11 and the first inductor, the second sub-switch 524 connects the second radiating stub 12 and the fourth inductor, and the third sub-switch 531 connects the third radiating stub 13 and the seventh inductor, the sub-band of the first frequency band supported by the first resonant mode switches to the B28 frequency band, the sub-band of the second frequency band supported by the second resonant mode switches to the high-frequency side of the B28 frequency band, and the sub-band of the third frequency band supported by the third resonant mode switches to the high-frequency side of the second frequency band. This is beneficial because the direction of the resonant current in the first radiating stub 11 of the first resonant mode is the same as the direction of the resonant current in the second radiating stub 12 of the second resonant mode, and the direction of the resonant current in the second radiating stub 12 of the second resonant mode is the same as the direction of the resonant current in the third radiating stub 13 of the third resonant mode. The third resonant mode and the second resonant mode are used to improve the radiation efficiency of the first frequency band.

[0190] When the first sub-switch 514 connects the first radiating stub 11 and the second inductor, the second sub-switch 524 connects the second radiating stub 12 and the fifth inductor, and the third sub-switch 531 connects the third radiating stub 13 and the eighth inductor, the sub-band of the first frequency band supported by the first resonant mode switches to the B8 frequency band, the sub-band of the second frequency band supported by the second resonant mode switches to the high-frequency side of the B8 frequency band, and the sub-band of the third frequency band supported by the third resonant mode switches to the high-frequency side of the second frequency band. This is beneficial because the direction of the resonant current in the first radiating stub 11 of the first resonant mode is the same as the direction of the resonant current in the second radiating stub 12 of the second resonant mode, the direction of the resonant current in the second radiating stub 12 of the second resonant mode is the same as the direction of the resonant current in the third radiating stub 13 of the third resonant mode, and the third resonant mode and the second resonant mode are used to improve the radiation efficiency of the first frequency band.

[0191] When the first sub-switch 514 connects the first radiating stub 11 and the third inductor, the second sub-switch 524 connects the second radiating stub 12 and the sixth inductor, and the third sub-switch 531 connects the third radiating stub 13 and the ninth inductor, the sub-band of the first frequency band supported by the first resonant mode switches to the B5 frequency band, the sub-band of the second frequency band supported by the second resonant mode switches to the high-frequency side of the B5 frequency band, and the sub-band of the third frequency band supported by the third resonant mode switches to the high-frequency side of the second frequency band. This is beneficial because the direction of the resonant current in the first radiating stub 11 of the first resonant mode is the same as the direction of the resonant current in the second radiating stub 12 of the second resonant mode, the direction of the resonant current in the second radiating stub 12 of the second resonant mode is the same as the direction of the resonant current in the third radiating stub 13 of the third resonant mode. The third resonant mode and the second resonant mode are used to improve the radiation efficiency of the first frequency band.

[0192] In this embodiment, by setting a first sub-switch 514 to switch different first tuning elements 515 and first radiating branches 11 to conduct, the sum of the electrical length of the first radiating branch 11 and the equivalent electrical length of the first tuning element 515 is changed; a second sub-switch 524 to switch different second tuning elements 525 and second radiating branches 12 to conduct, the sum of the electrical length of the second radiating branches 12 and the equivalent electrical length of the second tuning element 525 is changed; and a third sub-switch 531 to switch different third tuning elements 532 and third radiating branches 13 to conduct, the sum of the electrical length of the third radiating branches 13 and the equivalent electrical length of the third tuning element 532 is changed, so as to achieve switching support for different frequency bands in a small clearance environment, for example, switching from the B28 frequency band to the B8 frequency band, or switching from the B28 frequency band to the B5 frequency band, etc.

[0193] You can choose any one of the three optional implementation methods above, or any two of them, or all three of them at the same time.

[0194] Optionally, the first radial branch 11 is located near the first top edge 321a.

[0195] Optionally, the third radiating branch 13 is located near the first bottom edge 324a.

[0196] Optionally, the first radiating branch 11 is located near the first bottom frame 324a.

[0197] Optionally, the third radiating branch 13 is located near the first top edge 321a.

[0198] In a first alternative embodiment, referring to FIG18, the antenna assembly 100 further includes a second feed 22 and a first switching unit 61. The first switching unit 61 is electrically connected between the second feed 22 and the third radiating stub 13.

[0199] When the foldable electronic device 1000 is in its unfolded state, the first switching unit 61 connects the second feed source 22 and the third radiating stub 13. The second feed source 22 is used to excite the third radiating stub 13 to excite the fourth resonant mode supporting the fourth frequency band. Thus, in the unfolded state, the foldable electronic device 1000 can support at least the first frequency band and the fourth frequency band.

[0200] When the foldable electronic device 1000 is in a folded state, the first switching unit 61 disconnects the second feed 22 from the third radiating stub 13. Thus, in the folded state, the third radiating stub 13 can support the second frequency band, thereby improving the efficiency of the first frequency band in the folded state.

[0201] In a second optional embodiment, referring to FIG19, the antenna assembly 100 further includes a third feed 23 and a second switching unit 62. The second switching unit 62 is electrically connected between the third feed 23 and the second radiating stub 12. When the foldable electronic device 1000 is in the unfolded state, the second switching unit 62 connects the third feed 23 and the second radiating stub 12. The third feed 23 is used to excite the second radiating stub 12 to excite the fifth resonant mode supporting the fifth frequency band. Thus, in the unfolded state, the foldable electronic device 1000 can support at least the first and fifth frequency bands. When the foldable electronic device 1000 is in the folded state, the second switching unit 62 disconnects the third feed 23 from the second radiating stub 12. Thus, in the folded state, the second radiating stub 12 can support the third frequency band, thereby improving the efficiency of the first frequency band in the folded state.

[0202] The second feed source 22 and the third feed source 23 can be set either one or both simultaneously.

[0203] Please refer to Figures 20 to 23, which illustrate a foldable electronic device 1000 provided in Embodiment 3 of this application. The foldable electronic device 1000 includes a foldable frame 300, a first floor 510, a second floor 520, and an antenna assembly 100.

[0204] The foldable frame 300 includes a first side frame 322 and a second side frame 323 that are arranged opposite to each other.

[0205] When the foldable frame 300 is in a folded state, the first side frame 322 and the second side frame 323 are positioned opposite each other in the folding thickness direction.

[0206] The first floor 510 and the second floor 520 are movably connected to each other to be in a folded or unfolded state.

[0207] Please refer to Figures 20 to 23. The antenna assembly 100 includes a first radiating stub 11, a first feed 21, and a second radiating stub 12.

[0208] The first radial branch 11 is located on the first side frame 322. The first radial branch 11 is located along the first floor 510.

[0209] Please refer to Figures 20 and 21. The first radiating branch 11 includes a first grounding point D1, a first feed point A, and a first open end E1.

[0210] The first feed source 21 is electrically connected to the first feed point A and is used to excite the first radiating branch 11 to form a first resonant mode that supports the first frequency band.

[0211] In this embodiment, the first radiating branch 11, the first feed source 21, and the second radiating branch 12 can all refer to the relevant descriptions of the first radiating branch 11, the first feed source 21, and the second radiating branch 12 in the aforementioned embodiment 1.

[0212] Please refer to Figures 20 and 21. The second radial branch 12 is located on the second side frame 323. The second radial branch 12 is disposed along the second floor 520. The second radial branch 12 includes a second open end E2 and a third open end E3.

[0213] The second radiating branch 12 in this embodiment can be referred to the relevant description of the second radiating branch 12 in the aforementioned embodiment 1.

[0214] When the foldable electronic device 1000 is in a folded state, the second radiating stub 12 and the first radiating stub 11 are at least partially opposite each other in the fold thickness direction and form a first coupling gap G1. The first opening end E1 and the second opening end E2 are adjacent and coupled. Under the coupling of the first radiating stub 11, the second radiating stub 12 forms a second resonant mode supporting the second frequency band.

[0215] The foldable electronic device 1000 provided in this application generates a resonant current by fully exciting multiple radiating branches (first radiating branch 11, second radiating branch 12) to form a resonant mode when the foldable electronic device 1000 is in a folded state, thereby improving the radiation efficiency of the first frequency band of the foldable electronic device 1000 in the folded state.

[0216] In another alternative embodiment, referring to Figures 3 and 4, the third radiating branch 13 further includes a second grounding point D2. The second grounding point D2 is used for electrical connection to the first floor 510. The second grounding point D2 is located between the fourth opening end E4 and the first grounding point D1.

[0217] The second grounding point D2 is located between the fourth open end E4 and the first grounding point D1. The first grounding point D1 and the second grounding point D2 are spaced apart. Further optionally, the distance between the fourth open end E4 and the third open end E3 is less than the distance between the second grounding point D2 and the third open end E3.

[0218] Specifically, the first opening end E1 is located near the first top frame 321a, and the fourth opening end E4 is a certain distance from the first bottom frame 324a. The second opening end E2 is located near the second top frame 321b, and the third opening end E3 is a certain distance from the second bottom frame 324b. Therefore, the first gap and the second gap are not easily gripped by the hand.

[0219] For example, the first side frame 322 is also provided with a first gap, which is adjacent to the first open end E1. The first gap is opened on the first side frame 322 to form the first open end E1. The first side frame 322 is also provided with a second gap, which is adjacent to the fourth open end E4. The second gap is opened on the first side frame 322 to form the fourth open end E4.

[0220] A third gap is also provided on the second side frame 323, which is adjacent to the second open end E2. The third gap is opened on the second side frame 323 to form the second open end E2. A fourth gap is also provided on the second side frame 323, which is adjacent to the third open end E3. The fourth gap is opened on the second side frame 323 to form the third open end E3.

[0221] Optionally, in the folded state, the first open end E1 and the second open end E2 are directly opposite each other. The third open end E3 and the fourth open end E4 are directly opposite each other. Further, in the folded state, the first slit and the third slit are directly opposite each other, and the second slit and the fourth slit are directly opposite each other.

[0222] The first gap is located near the first radiating branch 11 where the electric field is relatively strong. The third gap is aligned with the first gap during folding so that the third gap can be coupled with the location where the electric field is relatively strong, thereby enhancing the coupling effect between the second radiating branch 12 and the first radiating branch 11.

[0223] The fourth slit is located at a position with a strong electric field on the second radiating branch 12. The fourth slit is aligned with the second slit during folding to facilitate coupling between the second slit and the position with a strong electric field, thereby enhancing the coupling effect between the third radiating branch 13 and the second radiating branch 12.

[0224] Optionally, the first resonant mode includes a 1 / 4 wavelength mode of the first frequency band. In other words, the electrical length between the first ground point D1 and the first open end E1 is approximately 1 / 4 wavelength of the center frequency of the first frequency band.

[0225] Optionally, the second resonant mode includes a half-wavelength mode of the second frequency band. In other words, the electrical length between the second opening end E2 and the third opening end E3 is close to half the wavelength of the center frequency of the second frequency band.

[0226] Optionally, the third resonant mode includes a 1 / 4 wavelength mode of the third frequency band. In other words, the electrical length between the second ground point D2 and the fourth open end E4 is approximately 1 / 4 wavelength of the center frequency of the third frequency band. Since the center frequency of the third frequency band is greater than the center frequency of the first frequency band, the electrical length between the second ground point D2 and the fourth open end E4 is less than the electrical length between the second ground point D2 and the fourth open end E4.

[0227] The resonant frequency of the second frequency band is higher than that of the first frequency band. The first resonant mode includes half the wavelength mode of the first frequency band. The second resonant mode includes half the wavelength mode of the second frequency band.

[0228] The direction of the first resonant current I1 in the first radiating stub 11 of the first resonant mode is the same as the direction of the second resonant current I2 in the second radiating stub 12 of the second resonant mode, so as to increase the radiation aperture.

[0229] Furthermore, in the folded state, the first ground current distribution Q1 formed on the first ground plane 510 by the first resonant mode is the same as the second ground current distribution Q2 formed on the second ground plane 520 by the second resonant mode. The more longitudinal current distribution on the reference ground plane 500, the greater the radiation contribution of the reference ground plane 500 to the first frequency band, and the greater the improvement in radiation efficiency for the first frequency band.

[0230] Further optionally, referring to Figures 22 and 23, the second radiating branch 12 also includes a fifth open end E5 and a third grounding point D3. The fifth open end E5 and the third open end E3 are spaced apart. Optionally, the fifth open end E5 and the third open end E3 have a relatively small gap, for example, the gap width between the fifth open end E5 and the third open end E3 is 0 to 2 mm.

[0231] The third grounding point D3 is electrically connected to the second floor 520.

[0232] Define the area between the second open end E2 and the third open end E3 as the first sub-segment 121, and define the area between the fifth open end E5 and the third grounding point D3 as the second sub-segment 122.

[0233] In an optional embodiment, referring to FIG22, the antenna assembly 100 further includes a capacitor element 41. One end of the capacitor element 41 is electrically connected to the third opening terminal E3, and the other end of the capacitor element 41 is electrically connected to the fifth opening terminal E5. The capacitor element 41 is used to enhance the coupling strength between the first sub-stub 121 and the second sub-stub 122 to promote a relatively strong second resonant current I2 distributed on both the first sub-stub 121 and the second sub-stub 122.

[0234] In another optional embodiment, the antenna assembly 100 further includes a conductive element 42. A portion of the conductive element 42 is opposite to and coupled to the third opening end E3, and another portion of the conductive element 42 is opposite to and coupled to the fifth opening end E5. The conductive element 42 includes, but is not limited to, a conductive strip or a conductive plate. For example, the conductive element 42 is a conductive plate. A portion of the conductive element 42 forms a capacitor structure with the end of the first sub-stub 121, and another portion of the conductive element 42 forms a capacitor structure with the end of the second sub-stub 122. The conductive element 42 is used to enhance the coupling strength between the first sub-stub 121 and the second sub-stub 122 to promote a relatively strong second resonant current I2 distributed on both the first sub-stub 121 and the second sub-stub 122.

[0235] For example, the first side frame 322 is also provided with a first gap, which is adjacent to the first open end E1. The first gap is opened on the first side frame 322 to form the first open end E1. The first side frame 322 is also provided with a second gap, which is adjacent to the fourth open end E4. The second gap is opened on the first side frame 322 to form the fourth open end E4.

[0236] A third gap is also provided on the second side frame 323, which is adjacent to the second open end E2. The third gap is opened on the second side frame 323 to form the second open end E2. A fourth gap is also provided on the second side frame 323, which is located between the third open end E3 and the fifth open end E5. The fourth gap is opened on the second side frame 323 to form the third open end E3 and the fifth open end E5.

[0237] Optionally, in the folded state, the first open end E1 is directly opposite the second open end E2. The third open end E3 is directly opposite the fourth open end E4.

[0238] Furthermore, in the folded state, the first slit is aligned with the third slit, and the second slit is aligned with the fourth slit.

[0239] The first gap is located near the first radiating branch 11 where the electric field is relatively strong. The third gap is aligned with the first gap during folding so that the third gap can be coupled with the location where the electric field is relatively strong, thereby enhancing the coupling effect between the second radiating branch 12 and the first radiating branch 11.

[0240] The fourth slit is located at a position with a strong electric field on the second radiating branch 12. The fourth slit is aligned with the second slit during folding to facilitate coupling between the second slit and the position with a strong electric field, thereby enhancing the coupling effect between the third radiating branch 13 and the second radiating branch 12.

[0241] Furthermore, in this embodiment, by placing the third radial branch 13 near the first bottom frame 324a and the second radial branch 12 near the second bottom frame 324b, the distance between the second gap and the first bottom frame 324a is relatively large, and the distance between the fourth gap and the second bottom frame is relatively large. Therefore, the first gap and the second gap are not easily gripped by the hand.

[0242] Optionally, the first resonant mode includes a 1 / 4 wavelength mode of the first frequency band. In other words, the electrical length between the first ground point D1 and the first open end E1 is approximately 1 / 4 wavelength of the center frequency of the first frequency band.

[0243] The third resonant mode includes a 1 / 4 wavelength mode of the third frequency band. In other words, the electrical length between the second ground point D2 and the fourth open end E4 is close to 1 / 4 wavelength of the center frequency of the third frequency band. Since the center frequency of the third frequency band is greater than the center frequency of the first frequency band, the electrical length between the second ground point D2 and the fourth open end E4 is less than the electrical length between the second ground point D2 and the fourth open end E4.

[0244] Please refer to Figures 16 and 17, which are schematic diagrams of the foldable electronic device 1000 provided in Embodiment 1 in its unfolded and folded states, respectively. The first radiating branch 11, matching circuit M1, and first feed 21 of the first main body 710 form an excitation source antenna. The third radiating branch 13 and first switching tuning circuit 51 of the first main body 710, and the second radiating branch 12 and second switching tuning circuit 52 of the second main body 720 are used to enhance the performance of the excitation source antenna in the folded state. Among them, the second radiating branch 12 is a suspended metal frame, and the third radiating branch 13 and the first radiating branch 11 are metal frames of a certain length that are connected to the reference ground plane 500.

[0245] Using the first feed 21 and a separately configured first radiating stub 11 as a comparative example. The first radiating stub 11 is located close to the first top edge 321a. Please refer to Figure 24, which shows the efficiency curves of the first feed 21 exciting the separately configured first radiating stub 11 in the unfolded and folded states. The first feed 21 exciting the first radiating stub 11 to operate in the B8 frequency band.

[0246] Curve a is the radiation efficiency curve of the first feed 21 exciting the first radiating branch 11 in the folded state. Curve b is the radiation efficiency curve of the first feed 21 exciting the first radiating branch 11 in the unfolded state. Curve c is the system efficiency curve of the first feed 21 exciting the first radiating branch 11 in the folded state. Curve d is the system efficiency curve of the first feed 21 exciting the first radiating branch 11 in the unfolded state.

[0247] As shown in the figure, when the foldable electronic device 1000 is unfolded, the first radiating branch 11 exhibits good performance in the low-frequency range, with a radiation efficiency of approximately -6.1 dB (resonance point at 915 MHz). This is because the first radiating branch 11 is generally distributed on the first side frame 322, which has good clearance, and the overall reference floor 500 is large, thus the first radiating branch 11 exhibits good performance in the low-frequency range.

[0248] As shown in the figure, when the foldable electronic device 1000 is in the folded state, the three-dimensional clearance of the first radiating branch 11 deteriorates sharply, leading to a sharp drop in radiation performance. The radiation efficiency is approximately -10.3 dB (resonance point is 915 MHz), a decrease of 4.1 dB. This is because the equivalent size of the reference floor 500 is halved, and the distance between the first radiating branch 11 and the second side frame 323 is very close (approximately 1.5 mm). The sharp deterioration of the three-dimensional clearance of the first radiating branch 11 leads to a sharp drop in radiation performance, indicating that the performance of the foldable electronic device 1000 in the folded state urgently needs improvement.

[0249] Referring to Figure 20, the first foldable electronic device 1000 provided in this application suspends a second radiating branch 12 corresponding to the first radiating branch 11 in the second body 720, coupling the radiated energy of the first radiating branch 11 to the second radiating branch 12. The second radiating branch 12 can act as a parasitic branch of the first radiating branch 11, exciting the current of the second ground 520 and the current of its own branch, generating a first resonant mode supporting the first frequency band and a second resonant mode supporting the second frequency band, increasing the impedance width, and effectively improving the performance of the antenna at B8 in the folded state, with the radiation efficiency decreasing by only 0.2dB (915MHz) compared to the unfolded state. The first radiating branch 11 is close to the first top edge 321a, and the second radiating branch 12 is close to the second top edge 321b.

[0250] Please refer to Figure 25. Figure 25 shows the S-parameter curves of the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 in the unfolded and folded states. Curve a is the S-parameter curve of the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 in the unfolded state. It can be seen that the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 generates a first resonant mode supporting the first frequency band in the unfolded state. Curve b is the S-parameter curve of the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 in the folded state. It can be seen that the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 generates a first resonant mode supporting the first frequency band and a second resonant mode supporting the second frequency band in the folded state, increasing the impedance bandwidth.

[0251] Please refer to Figure 26. Figure 26 shows the efficiency curves of the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 in the unfolded and folded states. Curve a is the radiation efficiency curve of the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 in the folded state. Curve b is the radiation efficiency curve of the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 in the unfolded state. Curve c is the system efficiency curve of the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 in the folded state. Curve d is the system efficiency curve of the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 in the unfolded state.

[0252] As shown in the figure, when the foldable electronic device 1000 is unfolded, the first radiating branch 11 exhibits good performance in the low-frequency range, with a radiation efficiency of approximately -6.1 dB (resonance point at 915 MHz). This is because the first radiating branch 11 is generally distributed on the first side frame 322, which has good clearance, and the overall reference floor 500 is large, thus the first radiating branch 11 exhibits good performance in the low-frequency range.

[0253] As shown in the figure, when the foldable electronic device 1000 is in the folded state, the radiation efficiency of the first radiating stub 11 in the first frequency band is approximately -6.39 dB (resonant point at 915 MHz), with a decrease in radiation efficiency of only 0.29 dB. Compared to the case without the second radiating stub 12, the radiation efficiency is improved by approximately 4 dB. This indicates that the radiation performance (system efficiency) after folding is higher on average within the B8 frequency band.

[0254] Referring to Figure 16, the second foldable electronic device 1000 provided in this application suspends a second radiating branch 12 corresponding to the first radiating branch 11 in the second body 720, coupling the radiated energy of the first radiating branch 11 to the second radiating branch 12. The second radiating branch 12 can act as a parasitic branch of the first radiating branch 11, exciting the current of the second ground 520 and the current of its own branch. A third radiating branch 13 is also provided on the first body 710. The third radiating branch 13 can act as a parasitic branch of the second radiating branch 12, exciting the current of the first ground 510 and the current of its own branch. This generates a first resonant mode supporting the first frequency band, a second resonant mode supporting the second frequency band, and a third resonant mode supporting the third frequency band, increasing the impedance width and effectively improving the performance of the antenna at B8 in the folded state, while also improving the radiation efficiency compared to the unfolded state.

[0255] Please refer to Figure 27. Figure 27 shows the efficiency curves of the foldable electronic device 1000 with the second radiating branch 12, the first radiating branch 11, and the third radiating branch 13 in the unfolded and folded states. Curve a is the radiation efficiency curve of the foldable electronic device 1000 with the second radiating branch 12, the first radiating branch 11, and the third radiating branch 13 in the folded state. Curve b is the radiation efficiency curve of the foldable electronic device 1000 with the second radiating branch 12, the first radiating branch 11, and the third radiating branch 13 in the unfolded state. Curve c is the system efficiency curve of the foldable electronic device 1000 with the second radiating branch 12, the first radiating branch 11, and the third radiating branch 13 in the folded state. Curve d is the system efficiency curve of the foldable electronic device 1000 with the second radiating branch 12, the first radiating branch 11, and the third radiating branch 13 in the unfolded state.

[0256] As shown in the figure, when the foldable electronic device 1000 is unfolded, the first radiating branch 11 exhibits good performance in the low-frequency range, with a radiation efficiency of approximately -6.1 dB (resonance point at 915 MHz). This is because the first radiating branch 11 is generally distributed on the first side frame 322, which has good clearance, and the overall reference floor 500 is large, thus the first radiating branch 11 exhibits good performance in the low-frequency range.

[0257] As shown in the figure, when the foldable electronic device 1000 is in the folded state, the radiation efficiency of the first radiating stub 11 in the first frequency band is approximately -5.27 dB (resonant point at 915 MHz). This indicates that the radiation efficiency in the folded state is 0.9 dB higher than in the unfolded state. Combined with impedance matching, the final radiation performance (system efficiency) of the radiating stub is significantly improved compared to the unfolded state, with an average improvement of approximately 1.7 dB. Compared to the state without the third radiating stub 13, the radiation efficiency is improved by approximately 1.1 dB, further enhancing the radiation performance in the folded state.

[0258] By setting a third radiating branch 13 on the first main body 710, the third radiating branch 13 can couple the electromagnetic energy on the second radiating branch 12 on the second main body 720, reducing the loss of electromagnetic energy at the second main body 720 due to absorption by the screen. The third radiating branch 13 and the first radiating branch 11 are both located on one side of the first ground plane 510, which better excites the current of the first ground plane 510 and has a better longitudinal radiation mode. The bottom of the motherboard also generates a current in the same direction near the first radiating branch 11. The longitudinal mode of the first ground plane 510 is more fully excited, and the reference ground plane 500 contributes more to the radiation of the first frequency band, thus improving the radiation efficiency of the first frequency band.

[0259] This application utilizes a second radiating branch 12 suspended and coupled to the first radiating branch 11 for electric field coupling. Furthermore, the other open end of the second radiating branch 12 can be effectively coupled to a third radiating branch 13, thereby transferring energy from the first radiating branch 11 to the third radiating branch 13 located on the first body 710, reducing energy distribution at the second body 720 and decreasing electromagnetic energy absorption by the screen of the second body 720. Additionally, the electrical size of the third radiating branch 13 located on the first body 710 can be adjusted to be less than one-quarter of the operating wavelength, assisting the first radiating branch 11 in more effectively exciting the reference floor 500, thereby improving radiation efficiency.

[0260] This application fully utilizes the space between the second body 720 and the first body 710, increasing parasitic radiating branches and greatly improving the situation of deteriorated radiation performance. The performance in the folded state is greatly improved, and under certain conditions, the system efficiency in the folded state is better than that in the unfolded state. The foldable electronic device 1000 provided by this application achieves better mode excitation and a better impedance bandwidth in the folded state, resulting in a significant improvement in the radiation performance of the antenna in the folded state, which is superior to that in the unfolded state.

[0261] The foldable electronic device 1000 provided in this application is in both an unfolded state and a folded state. The first radiating branch 11, matching circuit M1, and first feed 21 of the first main body 710 form an excitation source antenna. The third radiating branch 13 and third switching tuning circuit 53 of the first main body 710, and the third radiating branch 13 and second switching tuning circuit 52, and the second radiating branch 12 and first switching tuning circuit 51 of the second main body 720 are used to enhance the performance of the excitation source antenna in the folded state. The third radiating branch 13 is close to the first bottom frame 324a, and the second radiating branch 12 is close to the second bottom frame 324b. The second radiating branch 12 is a suspended metal frame, and the third radiating branch 13 and the second radiating branch 12 are metal frames of a certain length that are connected to the reference ground plane 500.

[0262] Using the first feed 21 and a separately configured first radiating stub 11 as a comparative example. The first radiating stub 11 is relatively close to the first bottom frame 324a. Please refer to Figure 28, which shows the efficiency curves of the first feed 21 exciting the separately configured first radiating stub 11 in the unfolded and folded states. The first feed 21 exciting the first radiating stub 11 to operate in the B8 frequency band.

[0263] Curve a is the radiation efficiency curve of the first feed 21 exciting the first radiating branch 11 in the folded state. Curve b is the radiation efficiency curve of the first feed 21 exciting the first radiating branch 11 in the unfolded state. Curve c is the system efficiency curve of the first feed 21 exciting the first radiating branch 11 in the folded state. Curve d is the system efficiency curve of the first feed 21 exciting the first radiating branch 11 in the unfolded state.

[0264] As shown in the figure, when the foldable electronic device 1000 is unfolded, the first radiating branch 11 exhibits good performance in the low-frequency range, with a radiation efficiency of approximately -4.1 dB (resonance point at 900 MHz). This is because the first radiating branch 11 is generally distributed on the first side frame 322, which has good clearance, and the overall reference floor 500 is large, thus the first radiating branch 11 exhibits good performance in the low-frequency range.

[0265] As shown in the figure, when the foldable electronic device 1000 is in the folded state, the three-dimensional clearance of the first radiating branch 11 deteriorates sharply, leading to a sharp drop in radiation performance. The radiation efficiency is approximately -11.3 dB (resonance point at 900 MHz), a decrease of 7.2 dB. This is because the equivalent size of the reference floor 500 is halved, and the distance between the first radiating branch 11 and the second side frame 323 is very close (approximately 1.5 mm). The sharp deterioration of the three-dimensional clearance of the first radiating branch 11 leads to a sharp drop in radiation performance, indicating that the performance of the foldable electronic device 1000 in the folded state urgently needs improvement.

[0266] Referring to Figure 22, the third foldable electronic device 1000 provided in this application suspends a second radiating branch 12 corresponding to the first radiating branch 11 in the second main body 720, coupling the radiated energy of the first radiating branch 11 to the second radiating branch 12. Simultaneously, a capacitor element 41 connects the first sub-branch 121 and the second sub-branch 122. Generally, the capacitor element 41 connects the first sub-branch 121 and the second sub-branch 122. This approach couples more energy from the first sub-branch 121 to the second sub-branch 122. Due to the combined effect of the first sub-branch 121 and the second sub-branch 122, the longitudinal current of the second ground 520 can be better excited, effectively improving the antenna performance at B8 in the folded state. The radiation efficiency decreases by only 0.7 dB (900 MHz) compared to the unfolded state. The second sub-branch 122 is close to the second bottom frame 324b.

[0267] Please refer to Figure 29, which shows the S-parameter curves of the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 in the unfolded and folded states. Curve a is the S-parameter curve of the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 in the unfolded state. It can be seen that the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 generates a first resonant mode supporting the first frequency band in the unfolded state. Curve b is the S-parameter curve of the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 in the folded state. It can be seen that the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 generates a first resonant mode supporting the first frequency band and a second resonant mode supporting the second frequency band in the folded state, increasing the impedance bandwidth.

[0268] Please refer to Figure 30, which shows the efficiency curves of the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 in the unfolded and folded states. Curve a is the radiation efficiency curve of the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 in the folded state. Curve b is the radiation efficiency curve of the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 in the unfolded state. Curve c is the system efficiency curve of the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 in the folded state. Curve d is the system efficiency curve of the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 in the unfolded state.

[0269] As shown in the figure, when the foldable electronic device 1000 is unfolded, the first radiating branch 11 exhibits good performance in the low-frequency range, with a radiation efficiency of approximately -4.1 dB (resonance point at 900 MHz). This is because the first radiating branch 11 is generally distributed on the first side frame 322, which has good clearance, and the overall reference floor 500 is large, thus the first radiating branch 11 exhibits good performance in the low-frequency range.

[0270] As shown in the figure, when the foldable electronic device 1000 is in the folded state, the radiation efficiency of the first radiating stub 11 in the first frequency band is approximately -4.86 dB (resonant point at 900 MHz), with a decrease in radiation efficiency of only 0.8 dB. Compared to the state without the second radiating stub 12, the radiation efficiency is improved by approximately 5.5 dB. This indicates that the average radiation performance (system efficiency) after folding is higher in the B8 frequency band. Its impedance bandwidth is better than in the unfolded state, and the final radiation performance (system efficiency) of the radiating stub is slightly better than in the unfolded state, with an improvement of 0.3 dB (900 MHz).

[0271] Referring to Figure 17, the fourth foldable electronic device 1000 provided in this application suspends a second radiating branch 12 corresponding to the first radiating branch 11 in the second main body 720, coupling the radiated energy of the first radiating branch 11 to the second radiating branch 12. Simultaneously, a capacitor element 41 connects the first sub-branch 121 and the second sub-branch 122. Generally, the capacitor element 41 is used to connect the first sub-branch 121 and the second sub-branch 122, which couples more energy from the first sub-branch 121 to the second sub-branch 122. Due to the combined effect of the first sub-branch 121 and the second sub-branch 122, the longitudinal current of the second ground 520 can be better excited, effectively improving the antenna performance at B8 in the folded state, with the radiation efficiency decreasing by only 0.7 dB (900 MHz) compared to the unfolded state. The second sub-branch 122 is located close to the second bottom frame 324b. A third radiating stub 13 is also provided on the first main body 710. The third radiating stub 13 can serve as a parasitic stub of the second radiating stub 12, exciting the current of the first ground 510 and the current of its own stub; generating a first resonant mode supporting the first frequency band, a second resonant mode supporting the second frequency band, and a third resonant mode supporting the third frequency band, increasing the impedance width, so that the performance of the antenna in B8 is effectively improved in the folded state, and the radiation efficiency is also improved compared to the unfolded state.

[0272] Please refer to Figure 31. Figure 31 shows the efficiency curves of the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 in the unfolded and folded states. Curve a is the radiation efficiency curve of the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 in the folded state. Curve b is the radiation efficiency curve of the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 in the unfolded state. Curve c is the system efficiency curve of the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 in the folded state. Curve d is the system efficiency curve of the foldable electronic device 1000 with the second radiating branch 12 and the first radiating branch 11 in the unfolded state.

[0273] As shown in the figure, when the foldable electronic device 1000 is unfolded, the first radiating branch 11 exhibits good performance in the low-frequency range, with a radiation efficiency of approximately -4.15 dB (resonance point at 900 MHz). This is because the first radiating branch 11 is generally distributed on the first side frame 322, which has good clearance, and the overall reference floor 500 is large, thus the first radiating branch 11 exhibits good performance in the low-frequency range.

[0274] As shown in the figure, when the foldable electronic device 1000 is in the folded state, the radiation efficiency of the first radiating stub 11 in the first frequency band is approximately -3.85 dB (resonant point at 900 MHz). This indicates that the radiation efficiency in the folded state is already 0.3 dB higher than in the unfolded state. Combined with impedance matching, the final radiation performance (system efficiency) of the radiating stub is significantly improved compared to the unfolded state, with an average improvement of approximately 1.7 dB. Compared to the state without the third radiating stub 13, the radiation efficiency is improved by approximately 1 dB, further enhancing the radiation performance in the folded state.

[0275] This application utilizes an equivalent capacitance element 41 to connect the first sub-stub 121 and the second sub-stub 122, ensuring that the first sub-stub 121 and the second sub-stub 122 maintain the same current direction within a larger physical dimension, thus better exciting the longitudinal current of the second ground 520. The equivalent capacitance element 41 between the first sub-stub 121 and the second sub-stub 122 ensures a strong coupling electric field between them, which is beneficial for the third radiating stub 13 of the first body 710 to couple more electromagnetic energy. This application also utilizes the third radiating stub 13 of the first body 710 to better excite the longitudinal current mode of the first body 710, while simultaneously reducing energy distribution at the second body 720 and reducing the absorption of electromagnetic energy by the screen of the second body 720. This application fully utilizes the space between the second body 720 and the first body 710, increasing parasitic radiating stubs, ultimately achieving better low-frequency folded radiation performance than unfolded radiation performance—an effect not yet achieved by any previous folding antenna design.

[0276] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application, and such improvements and refinements are also considered to be within the protection scope of this application.

Claims

1. A foldable electronic device, wherein, include: A foldable frame includes a first side frame and a second side frame that are arranged opposite to each other. When the foldable frame is in a folded state, the first side frame and the second side frame are arranged opposite to each other in the folding thickness direction. Antenna assembly, the antenna assembly comprising: The first radial branch is located on the first side frame; A first feed source, electrically connected to the first radiating stub, is used to excite the first radiating stub to form a first resonant mode supporting the first frequency band. The second radiating branch is disposed on the second side frame. When the foldable electronic device is in a folded state, the second radiating branch is at least partially opposite to the first radiating branch in the folding thickness direction and forms a first coupling gap. The second radiating branch forms a second resonant mode supporting the second frequency band under the coupling of the first radiating branch. The third radiating branch is disposed on the first side frame and is spaced apart from the first radiating branch along the extension direction of the first side frame. When the foldable electronic device is in a folded state, the third radiating branch and the second radiating branch are at least partially opposite each other in the folding thickness direction and form a second coupling gap. The third radiating branch forms a third resonant mode supporting a third frequency band under the coupling of the second radiating branch.

2. The foldable electronic device of claim 1, wherein, The foldable electronic device further includes a first floor and a second floor, the first floor and the second floor being movably connected to each other to be in a folded state or an unfolded state; The first radiating branch is disposed along the first floor, and the second radiating branch is disposed along the second floor; In the first resonant mode, a first ground current distribution is formed along the first side frame on the first ground plane. In the second resonant mode, a second ground current distribution is formed along the second side frame on the second ground, and the direction of the first ground current distribution is the same as the direction of the second ground current distribution.

3. The foldable electronic device of claim 2, wherein, In the third resonant mode, a third ground current distribution is formed along the first side frame on the first ground plane, and the direction of the third ground current distribution is the same as the direction of the first ground current distribution.

4. The foldable electronic device of claim 1, wherein, The direction of the resonant current of the first resonant mode on the first radiating stub is the same as the direction of the resonant current of the second resonant mode on the second radiating stub, and the direction of the resonant current of the second resonant mode on the second radiating stub is the same as the direction of the resonant current of the third resonant mode on the third radiating stub.

5. The foldable electronic device of claim 1, wherein, The center frequency of the first frequency band is less than the center frequency of the second frequency band, and the center frequency of the second frequency band is less than the center frequency of the third frequency band.

6. The foldable electronic device of claim 5, wherein, The antenna assembly includes: A first switching tuning circuit, electrically connected to the first radiating stub, is used to tune the center frequency of the first frequency band to be lower than the center frequency of the second frequency band; and / or A second switching tuning circuit, electrically connected to the second radiating stub, is used to tune the center frequency of the second frequency band to be greater than the center frequency of the first frequency band and less than the center frequency of the third frequency band; and / or, A third switching tuning circuit is electrically connected to the third radiating stub, and the third switching tuning circuit is used to tune the center frequency of the third frequency band to be greater than the center frequency of the second frequency band.

7. The foldable electronic device of claim 2, wherein, The first radiating branch includes a first grounding point, a first feed point, and a first open end. The first grounding point is electrically connected to the first floor, and the first feed point is electrically connected to the first feed source. The second radiating branch includes a second open end, wherein the first open end and the second open end are adjacent to and coupled to each other when the foldable electronic device is in a folded state.

8. The foldable electronic device of claim 7, wherein, The second radial branch also includes a third open end. The third radiating branch also includes a fourth opening end, which is adjacent to and coupled to the third opening end when the foldable electronic device is in a folded state.

9. The foldable electronic device of claim 8, wherein, The third radiating branch also includes a second grounding point, which is used to electrically connect to the first floor and is located on the side of the fourth opening away from the first grounding point.

10. The foldable electronic device of claim 8, wherein, The second radiating branch also includes a fifth open end and a third grounding point, the fifth open end and the third open end being spaced apart; the third grounding point is electrically connected to the second floor. The antenna assembly further includes a capacitor element, one end of which is electrically connected to the third opening, and the other end of which is electrically connected to the fifth opening; or... The antenna assembly further includes a conductive element, a portion of which is opposite to and coupled to the third opening, and another portion of which is opposite to and coupled to the fifth opening.

11. The foldable electronic device of claim 10, wherein, The third radiating branch also includes a second grounding point, which is used to electrically connect to the first floor and is located between the fourth opening and the first grounding point.

12. The foldable electronic device of claim 11, wherein, The first resonant mode includes a 1 / 4 wavelength mode of the first frequency band, the second resonant mode includes a 1 / 2 wavelength mode of the second frequency band, and the third resonant mode includes a 1 / 4 wavelength mode of the third frequency band.

13. The foldable electronic device of claim 8, wherein, In the folded state, the first opening end is directly opposite the second opening end; the third opening end is directly opposite the fourth opening end.

14. The foldable electronic device of any of claims 1-13, wherein, The maximum value of the first frequency band is less than 1 GHz.

15. The foldable electronic device of any of claims 1-13, wherein, The foldable electronic device further includes a foldable screen and a secondary screen. The two sides of the foldable screen are respectively connected to the first side frame and the second side frame. The secondary screen is disposed opposite to the foldable screen, and one side of the secondary screen is connected to the second side frame.

16. The foldable electronic device of any of claims 1-13, wherein, The foldable frame further includes a first top frame and a first bottom frame, the first top frame and the first bottom frame being connected to the first side frame respectively, the first radial branch being located near the first top frame, or the third radial branch being located near the first bottom frame; or the first radial branch being located near the first bottom frame, or the third radial branch being located near the first top frame.

17. The foldable electronic device of any of claims 1-13, wherein, The antenna assembly further includes a second feed and a first switching unit. The first switching unit is electrically connected between the second feed and the second radiating stub. When the foldable electronic device is in the unfolded state, the first switching unit connects the second feed and the second radiating stub, and the second feed is used to excite the second radiating stub to excite a fourth resonant mode supporting the fourth frequency band. When the foldable electronic device is in the folded state, the first switching unit disconnects the second feed from the second radiating stub; and / or... The antenna assembly further includes a third feed and a second switching unit. The second switching unit is electrically connected between the third feed and the third radiating stub. When the foldable electronic device is in the unfolded state, the second switching unit connects the third feed and the third radiating stub. The third feed is used to excite the third radiating stub to excite the fifth resonant mode supporting the fifth frequency band. When the foldable electronic device is in the folded state, the second switching unit disconnects the third feed and the third radiating stub.

18. A foldable electronic device, wherein, include: A foldable frame includes a first side frame and a second side frame that are arranged opposite to each other. When the foldable frame is in a folded state, the first side frame and the second side frame are arranged opposite to each other in the folding thickness direction. A first floor and a second floor, wherein the first floor and the second floor are movably connected to each other to be in a folded or unfolded state; Antenna assembly, the antenna assembly comprising: A first radiating branch is provided on the first side frame, and the first radiating branch is arranged along the first floor. The first radiating branch includes a first grounding point, a first feed point, and a first open end; A first feed source, electrically connected to the first feed point, is used to excite the first radiating stub to form a first resonant mode supporting the first frequency band. The second radiating branch is located on the second side frame and is arranged along the second floor. The second radiating branch includes a second open end and a third open end. When the foldable electronic device is in a folded state, the second radiating stub and the first radiating stub are at least partially opposite each other in the fold thickness direction and form a first coupling gap, the first opening end is adjacent to and coupled to the second opening end; the second radiating stub forms a second resonant mode supporting the second frequency band under the coupling of the first radiating stub.

19. The foldable electronic device of claim 18, wherein, The resonant frequency of the second frequency band is greater than that of the first frequency band, and the second resonant mode includes the half-wavelength mode of the second frequency band.

20. The foldable electronic device of claim 18, wherein, The second radiating branch also includes a fifth open end and a third grounding point, the fifth open end and the third open end being spaced apart; the third grounding point is electrically connected to the second floor. The antenna assembly further includes a capacitor element, one end of which is electrically connected to the third opening and the other end of which is electrically connected to the fifth opening; or, the antenna assembly further includes a conductive element, a portion of which is opposite to and coupled to the third opening and another portion of which is opposite to and coupled to the fifth opening.

Images