Patent Publication Number: US-2022223999-A1

Title: Electronic device

Description:
This disclosure is a National Stage of International Patent Application No. PCT/CN2020/089827, filed on May 12, 2020, which claims priority to Chinese Patent Application No. 201910393785.6, filed on May 13, 2019 and Chinese Patent Application No. 201910435969.4, filed on May 23, 2019, all of which are incorporated herein by reference in their entireties. 
    
    
     TECHNICAL FIELD 
     Embodiments of this disclosure relate to the field of wireless communications technologies, and in particular, to an electronic device. 
     BACKGROUND 
     With technical development of components such as a flexible display, an identity (ID) form of an electronic device (for example, a mobile phone) tends to develop from a bar phone to a foldable phone. In an open state, the foldable phone has a large-area screen, which fully meets visual experience of consumers. In a closed state, the foldable phone is quite small in volume and easy to carry. However, when the foldable phone is in the closed state, antenna performance of a low-band antenna in a conventional antenna architecture significantly decreases compared with antenna performance in the open state, and the antenna performance is poor. 
     SUMMARY 
     Embodiments of this disclosure provide an electronic device. The electronic device has relatively high antenna performance in a closed state. 
     An embodiment of this disclosure provides an electronic device, including a first part and a second part. The first part and the second part can be folded relative to each other to a closed state, and can be expanded relative to each other to an open state. When the first part and the second part are in the closed state, a frame of the first part and a frame of the second part partially or totally overlap. 
     The first part includes a first feeding antenna, a first feeding circuit, and a first grounding circuit. The first feeding circuit is connected to the first feeding antenna, and is configured to feed the first feeding antenna. The first grounding circuit is connected to the first feeding antenna, and is configured to enable the first feeding antenna to be grounded. 
     The second part includes a first parasitic antenna. When the first part and the second part are in the closed state, the first parasitic antenna is not grounded and can be coupled to the first feeding antenna to generate a first excited resonance signal through excitation. 
     In an embodiment, when the first part and the second part are in the closed state, the first parasitic antenna and the first feeding antenna are disposed at least partially opposite to each other to generate a coupling capacitor between the first parasitic antenna and the first feeding antenna, so that the first excited resonance signal can be generated through coupling. When the first feeding antenna works, radio frequency energy of the first feeding antenna is transmitted to the first parasitic antenna through coupling, so that an additional resonance mode is generated through excitation on the first parasitic antenna, radiating frequency bandwidth of the antenna is extended, adverse impact on antenna performance that is caused by a reduction in a length of a ground plane and frame overlap in the closed state is reduced, and antenna performance of the electronic device is improved, that is, the electronic device has relatively high antenna performance in the closed state. When the first parasitic antenna is not grounded, an electrical length is ½ wavelength, in other words, the first parasitic antenna is a ½ wavelength antenna. In this case, the reduction in the length of the ground plane during folding has relatively weak impact on performance of the first parasitic antenna, so that the first parasitic antenna can maintain good radiation performance when the first part and the second part are in the closed state, thereby effectively extending radiating frequency bandwidth of the first feeding antenna. 
     In an embodiment, a matching circuit may be further disposed between the first feeding circuit and the first feeding antenna, and the matching circuit is configured to match feature impedance. The matching circuit may include at least one circuit component. For example, the matching circuit may include at least one of a resistor, an inductor, or a capacitor used as lumped elements. For example, the matching circuit may include at least one of a microstrip and a strip used as distribution elements. 
     In an embodiment, the second part further includes a second feeding antenna. The second feeding antenna is electrically isolated from the first parasitic antenna. When the first part and the second part are in the open state, the first parasitic antenna can be coupled to the second feeding antenna to generate a second excited resonance signal through excitation. 
     In this embodiment, when the first part and the second part are in the open state, the first parasitic antenna can be coupled to the second feeding antenna, and a coupling capacitor is generated between the first parasitic antenna and the second feeding antenna, so that the second excited resonance signal can be generated through coupling and excitation. When the second feeding antenna works, radio frequency energy of the second feeding antenna is transmitted to the first parasitic antenna through coupling, so that an additional resonance mode is generated through excitation on the first parasitic antenna, thereby extending radiating frequency bandwidth of the antenna and improving antenna performance of the electronic device. Because the first parasitic antenna can be coupled to the first feeding antenna when the first part and the second part are in the closed state, and can be coupled to the second feeding antenna when the first part and the second part are in the open state, the electronic device can multiplex the first parasitic antenna, so that antenna utilization is improved. 
     In an embodiment, when the first part and the second part are in the open state, the first feeding antenna, the second feeding antenna, and the first parasitic antenna are located in different corner regions of the electronic device. In this case, the first feeding antenna and the second feeding antenna may work in close frequency bands, and the first feeding antenna and the second feeding antenna have relatively large space and a relatively low degree of mutual interference. The first parasitic antenna may also be better separately coupled to the first feeding antenna and the second feeding antenna in the two states. 
     In an embodiment, the second part further includes a second feeding circuit and a second grounding circuit. The second grounding circuit is connected to one end of the second feeding antenna, and is configured to enable the second feeding antenna to be grounded. The other end of the second feeding antenna is an ungrounded open end. The second feeding circuit is connected to the second feeding antenna, and a connection position of the second feeding circuit on the second feeding antenna is located between a connection position of the second grounding circuit on the second feeding antenna and the open end. In this case, the second feeding antenna is a ¼ wavelength antenna. When the first part and the second part are in the open state, the first parasitic antenna is grounded. In this case, an electrical length of the first parasitic antenna is ¼ wavelength, in other words, the first parasitic antenna is a ¼ wavelength antenna. The electrical length of the first parasitic antenna is adjustable, so that there can be different electrical lengths in different use environments. 
     In an embodiment, a coupling effect between the first parasitic antenna and the second feeding antenna is excellent, and bandwidth of the second feeding antenna can be extended to a relatively large extent. To improve the coupling effect, for example, an end of the second feeding antenna that is away from the first parasitic antenna is a grounding end, and an end of the second feeding antenna that is close to the first parasitic antenna is an open end. 
     In an embodiment, a matching circuit may be further disposed between the second feeding circuit and the second feeding antenna, and the matching circuit is configured to match feature impedance. The matching circuit may include at least one circuit component. For example, the matching circuit may include at least one of a resistor, an inductor, or a capacitor used as lumped elements. For example, the matching circuit may include at least one of a microstrip and a strip used as distribution elements. 
     In an embodiment, the second part further includes a switching circuit. One end of the switching circuit is connected to the first parasitic antenna, and the other end is grounded. The switching circuit is configured to disconnect the first parasitic antenna from the ground when the first part and the second part are in the closed state. In this case, the electrical length of the first parasitic antenna is ½ wavelength. The switching circuit is further configured to connect the first parasitic antenna to the ground when the first part and the second part are in the open state. In this case, the electrical length of the first parasitic antenna is ¼ wavelength. 
     In an embodiment, by disposing the switching circuit, the electrical length of the first parasitic antenna is adjustable, and the first parasitic antenna can implement different coupling functions when the electronic device is in different use states, so that the antenna is multiplexed. 
     For example, the switching circuit may include a tuning switch. The switching circuit switches a connection relationship between the first parasitic antenna and the ground by switching the tuning switch between a closed state and an open state, so that the electrical length of the first parasitic antenna is adjustable. For example, the tuning switch may be roughly connected to a middle part of the first parasitic antenna. In this disclosure, a middle part of an antenna includes a central location and another location that slightly deviates from the central location, and the middle part of the antenna is located between both ends of the antenna. The middle part of the first parasitic antenna is located between both ends of the first parasitic antenna. 
     For another example, the switching circuit may include a tuning switch, a first matching branch, and a second matching branch. The first matching branch is different from the second matching branch. A control end of the tuning switch is connected to the first parasitic antenna, and two selection ends of the tuning switch are connected to the first matching branch and the second matching branch. The switching circuit switches a connection relationship between the first parasitic antenna and the ground by switching a connection between the first matching branch and the second matching branch by using the control end of the tuning switch, so that the electrical length of the first parasitic antenna is adjustable. 
     In an embodiment, the first part further includes a second parasitic antenna. When the first part and the second part are in the closed state, the second parasitic antenna is not grounded and can be coupled to the second feeding antenna to generate a third excited resonance signal through excitation. In this case, the second parasitic antenna is a ½ wavelength antenna. When the first part and the second part are in the open state, the second parasitic antenna may be located in an upper left corner of the electronic device. The second parasitic antenna, the first feeding antenna, the second feeding antenna, and the first parasitic antenna are located in different corner regions of the electronic device. When the first part and the second part are in the open state, the second parasitic antenna can be coupled to the first feeding antenna to generate a fourth excited resonance signal through excitation. In this case, the second parasitic antenna may be grounded. 
     In an embodiment, the switching circuit and a physical length of a metal segment in which the first parasitic antenna is located may be designed, so that the first parasitic antenna is switched between a grounded state and an ungrounded state, in other words, the electrical length of the first parasitic antenna is switched between ½ wavelength and ¼ wavelength. 
     In an embodiment, the second part further includes one or more first tuning circuits. The one or more first tuning circuits are connected to the first parasitic antenna. The first tuning circuit is configured to adjust the electrical length of the first parasitic antenna. In this embodiment, the one or more tuning circuits are connected to the first parasitic antenna, so that the electrical length of the first parasitic antenna meets an adjustment requirement through coordination of the one or more tuning circuits. 
     The one or more first tuning circuits may be connected to an end of the first parasitic antenna, to better perform a tuning function. For example, the second part includes two first tuning circuits, and the two first tuning circuits are separately connected to both ends of the first parasitic antenna. The first tuning circuit may include one or more of a switch, a capacitor, an inductor, or a low-pass high-cut filter. 
     In an embodiment, the second part further includes a second feeding antenna, a second feeding circuit, and a second grounding circuit. The second feeding antenna is electrically isolated from the first parasitic antenna. The second grounding circuit is connected to a middle part of the second feeding antenna. Both ends of the second feeding antenna are ungrounded open ends. The second feeding circuit is connected to the second feeding antenna, and a connection position of the second feeding circuit on the second feeding antenna is located between a connection position of the second grounding circuit on the second feeding antenna and one end of the second feeding antenna. In this case, the second feeding antenna is a ½ wavelength antenna. The first parasitic antenna is a floating antenna. In other words, the first parasitic antenna is not grounded. 
     In an embodiment, when the first part and the second part are in the open state, the second feeding antenna has two antenna modes, has relatively large bandwidth, and has relatively high antenna performance. Therefore, the second feeding antenna may not be coupled to the first parasitic antenna. When the first part and the second part are in the closed state, the first feeding antenna is coupled to the first parasitic antenna of ½ wavelength, to improve antenna performance of the first feeding antenna and reduce adverse impact of an external environment. In this case, for the antenna architecture, there is no need to switch between different antenna coupling forms when the first part and the second part are in different states, in other words, the first parasitic antenna may be a single ½ wavelength antenna, and no switching circuit needs to be disposed, so that a structure of the antenna architecture is simpler. 
     In an embodiment, the electronic device further includes a fifth feeding antenna, a fifth feeding circuit, a fifth grounding circuit, and a third parasitic antenna. The fifth feeding antenna is located in the second part, and the third parasitic antenna is located in the first part (in another embodiment, the fifth feeding antenna may be located in the first part, and the third parasitic antenna may be located in the second part). The fifth feeding antenna is electrically isolated from the first parasitic antenna and the second feeding antenna. The fifth feeding circuit is connected to the fifth feeding antenna, and is configured to feed the fifth feeding antenna. The fifth grounding circuit is connected to the fifth feeding antenna, and is configured to enable the fifth feeding antenna to be grounded. When the first part and the second part are in the closed state, the third parasitic antenna is not grounded and can be coupled to the fifth feeding antenna to generate a fifth excited resonance signal through excitation. In this case, an electrical length of the third parasitic antenna is ½ wavelength, in other words, the third parasitic antenna is a ½ wavelength antenna. In an embodiment, the fifth feeding antenna may be configured to radiate a medium- and high-frequency signal. 
     In an embodiment, the electronic device further includes a rotation part. The rotation part connects the first part and the second part. The rotation part can be deformed, so that the first part and the second part rotate relative to each other to fold or expand. The rotation part is located in a central region of the electronic device. That the rotation part is located in a central region of the electronic device means that a center line of the rotation part roughly coincides with a center line of the electronic device (a slight deviation is allowed). When the first part and the second part are in the closed state, the first part and the second part overlap, and a frame of the first part and a frame of the second part totally overlap. In this case, the frame of the first part and the frame of the second part are disposed entirely opposite to each other. 
     When the first part and the second part are in the open state, the first feeding antenna, the second feeding antenna, and the first parasitic antenna are located in different corner regions of the electronic device. In this case, the first feeding antenna and the second feeding antenna may work in close frequency bands, and the first feeding antenna and the second feeding antenna have relatively large space and a relatively low degree of mutual interference. The first parasitic antenna may also be better separately coupled to the first feeding antenna and the second feeding antenna in the two states. 
     In an embodiment, the electronic device further includes a rotation part. The rotation part connects the first part and the second part. The rotation part can be deformed, so that the first part and the second part rotate relative to each other to fold or expand. The rotation part deviates from a central region of the electronic device. In this case, a deviation between a center line of the rotation part and a center line of the electronic device is relatively large. When the first part and the second part are in the closed state, an end of one of the first part and the second part protrudes relative to the other part. 
     When the first part and the second part are in the open state, the electronic device includes two side edges spanning the rotation part, the first feeding antenna and the first parasitic antenna are located on a same side edge, and the second feeding antenna and the first feeding antenna are located on different side edges. In this case, when the first part and the second part are in the closed state, the first feeding antenna and the first parasitic antenna can be coupled to each other. The second feeding antenna and the first feeding antenna are located on different side edges. In this case, both the first feeding antenna and the second feeding antenna have relatively large radiation space. 
     The first parasitic antenna may extend from a side edge of the electronic device to another edge of the electronic device along an edge of a corner region. The second parasitic antenna may extend from the other side edge of the electronic device to another edge of the electronic device along another corner region. 
     In an embodiment, the first part is slidably connected to the second part. When sliding relative to each other, the first part and the second part can be folded relative to each other to the closed state, and can also be expanded relative to each other to the open state. When the first part and the second part are in the closed state, the first part and the second part are vertically stacked. When the first part and the second part are in the open state, a small portion of the first part  10  and a small portion of the second part remain in a stacked state, and most of the first part and most of the second part are in a staggered state, namely, an expanded state. In an embodiment, when the first part and the second part are in the open state, the first part and the second part may be totally staggered. 
     When the first part and the second part are in the closed state, the first feeding antenna and the second feeding antenna are separately located in two diagonally disposed corner regions of the electronic device. In this case, both the first feeding antenna and the second feeding antenna have relatively sufficient radiation space. 
     In an embodiment, the first feeding antenna and the first parasitic antenna are a part of a frame of the electronic device. The frame of the electronic device includes the frame of the first part and the frame of the second part. For example, the frame of the first part includes at least two metal segments and at least one insulation segment for electrically isolating the at least two metal segments. The first feeding antenna may be formed in one of the metal segments. The frame of the second part includes at least two metal segments and at least one insulation segment for electrically isolating the at least two metal segments. The first parasitic antenna may be formed in one of the metal segments. 
     Alternatively, the first feeding antenna and the first parasitic antenna are fastened to an inner side of a frame of the electronic device. For example, the first feeding antenna is fastened to an inner side of the frame of the first part. The first parasitic antenna is fastened to an inner side of the frame of the second part. In this case, a structural form of the first feeding antenna may be a flexible circuit board, a laser direct structuring (LDS) metal, an insert molding metal, or a wire of a printed circuit board. 
     In an embodiment, the first part further includes a second parasitic antenna. When the first part and the second part are in the closed state, the second parasitic antenna is not grounded and can be coupled to the second feeding antenna to generate a third excited resonance signal through excitation. In this case, the second parasitic antenna is a ½ wavelength antenna. When the first part and the second part are in the open state, the second parasitic antenna may be located in an upper left corner of the electronic device. The second parasitic antenna, the first feeding antenna, the second feeding antenna, and the first parasitic antenna are located in different corner regions of the electronic device. When the first part and the second part are in the open state, the second parasitic antenna can be coupled to the first feeding antenna to generate a fourth excited resonance signal through excitation. In this case, the second parasitic antenna may be grounded. 
     In an embodiment, the second part further includes a third feeding circuit and a first filter circuit. The third feeding circuit and the first filter circuit are connected to different locations of the first parasitic antenna, and are configured to form a third feeding antenna on the first parasitic antenna. A radiating frequency band of the third feeding antenna is different from a radiating frequency band of the first feeding antenna. For example, the first feeding antenna is a low-band antenna. The radiating frequency band of the third feeding antenna is a wireless local area network antenna, a short-range wireless communications antenna, a medium- and high-band antenna, a sub 6G antenna (a frequency is less than 6 GHz), a wireless charging antenna, or the like. In this case, the first filter circuit has a low-cut and high-pass feature. For example, the first filter circuit includes a high-pass low-cut filter. 
     In this case, the third feeding antenna and the first parasitic antenna share a same segment of radiator, so that antenna utilization can be improved. In addition, because the radiating frequency band of the third feeding antenna is different from the radiating frequency band of the first feeding antenna, the third feeding antenna and the first feeding antenna do not interfere with each other, and are well isolated. 
     In an embodiment, the electronic device further includes a fourth feeding antenna, a fourth feeding circuit, and a second filter circuit. The fourth feeding antenna is adjacent to and electrically isolated from the first parasitic antenna. The fourth feeding circuit is connected to the fourth feeding antenna. The filter circuit is connected to the first parasitic antenna. A radiating frequency band of the fourth feeding antenna is different from a radiating frequency band of the first feeding antenna. For example, the first feeding antenna is a low-band antenna. The radiating frequency band of the fourth feeding antenna is a wireless local area network antenna, a short-range wireless communications antenna, a medium- and high-band antenna, a wireless charging antenna, or the like. In this case, the second filter circuit has a low-cut and high-pass feature. For example, the second filter circuit includes a high-pass low-cut filter. 
     In this case, a radiator part in which the first parasitic antenna is located is used as a parasitic branch of the fourth feeding antenna to implement multiplexing, so that antenna utilization can be improved. In addition, because the radiating frequency band of the fourth feeding antenna is different from the radiating frequency band of the first feeding antenna, the fourth feeding antenna and the first feeding antenna do not interfere with each other, and are well isolated. 
     The fourth feeding antenna may be located in the first part or the second part. A connection position of the fourth feeding antenna on the first parasitic antenna is located between a connection position of the switching circuit on the first parasitic antenna and the fourth feeding antenna. 
     In an embodiment, the electronic device further includes a sensing apparatus. The sensing apparatus is located in the first part and/or the second part. The sensing apparatus is configured to sense that the first part and the second part are in the closed state or the open state. The sensing apparatus is electrically connected to a processor of the electronic device. The processor is located in the first part and/or the second part. The processor of the electronic device receives a detection signal of the sensing apparatus, and sends a corresponding control signal to another component of the electronic device based on the signal, so that the another component of the electronic device can be adjusted to a corresponding working mode in a timely manner depending on whether the first part and the second part are in the closed state or the open state. In this way, the electronic device has higher reliability and better user experience. The sensing apparatus may include one or more of a gyroscope sensor, a Hall effect sensor, or a proximity light sensor. 
     In an embodiment, the electronic device further includes a display. The display is configured to display an image, a video, and the like. In this embodiment, the display is a flexible display. The display can be continuously located on a same side of the first part, the rotation part, and the second part, so that when the first part and the second part are in the open state, the electronic device has a continuous large-area display, to implement large-screen display, and when the first part and the second part are in the closed state, the electronic device can implement display on the front, the back, and the side of the electronic device. 
     In an embodiment, the electronic device further includes a ground plane. The ground plane is grounded and extends from the first part to the second part. In an embodiment, the ground plane is a circuit board of the electronic device. For example, the ground plane may be a flexible circuit board, or the ground plane is a flexible-rigid circuit board. In another embodiment, the ground plane may be integrated into another component, for example, the display, of the electronic device. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic structural diagram of an electronic device in a first embodiment according to the embodiments of this disclosure; 
         FIG. 2  is a schematic structural diagram of the electronic device shown in  FIG. 1  in another use state; 
         FIG. 3  is a schematic structural diagram of the electronic device shown in  FIG. 2  from another angle; 
         FIG. 4  is a reflection coefficient line graph of an example structure of the electronic device shown in  FIG. 1 ; 
         FIG. 5  is an efficiency line graph of an example structure of the electronic device shown in  FIG. 1 ; 
         FIG. 6  is a schematic diagram of an antenna architecture of the electronic device shown in  FIG. 1  in an embodiment; 
         FIG. 7  is a schematic diagram of the antenna architecture shown in  FIG. 6  when an electronic device is in another use state; 
         FIG. 8  is a reflection coefficient line graph of an example structure of the antenna architecture shown in  FIG. 6 ; 
         FIG. 9  is an efficiency line graph of an example structure of the antenna architecture shown in  FIG. 6 ; 
         FIG. 10  is a simulation diagram of a current and an electric field in an example structure of the antenna architecture shown in  FIG. 6 ; 
         FIG. 11  is a reflection coefficient line graph of another example structure of the antenna architecture shown in  FIG. 6 ; 
         FIG. 12  is an efficiency line graph of another example structure of the antenna architecture shown in  FIG. 6 ; 
         FIG. 13  is a schematic diagram of an antenna architecture of the electronic device shown in  FIG. 1  in another embodiment; 
         FIG. 14  is a schematic diagram of an antenna architecture of the electronic device shown in  FIG. 1  in another embodiment; 
         FIG. 15  is a schematic diagram of an antenna architecture of the electronic device shown in  FIG. 1  in another embodiment; 
         FIG. 16  is a schematic diagram of an antenna architecture of the electronic device shown in  FIG. 1  in another embodiment; 
         FIG. 17  is a schematic diagram of an antenna architecture of the electronic device shown in  FIG. 1  in another embodiment; 
         FIG. 18  is a schematic diagram of the antenna architecture shown in  FIG. 17  in another use state; 
         FIG. 19  is a reflection coefficient line graph of a second feeding antenna in an example structure of the antenna architecture shown in  FIG. 17 ; 
         FIG. 20  is an efficiency line graph of a second feeding antenna in an example structure of the antenna architecture shown in  FIG. 17 ; 
         FIG. 21  shows simulation of a current, an electric field, and a radiation direction of a second feeding antenna in an example structure of the antenna architecture shown in  FIG. 17 ; 
         FIG. 22  is a reflection coefficient line graph of an example structure of the antenna architecture shown in  FIG. 17 ; 
         FIG. 23  is an efficiency line graph of an example structure of the antenna architecture shown in  FIG. 17 ; 
         FIG. 24  is a schematic diagram of an antenna architecture of the electronic device shown in  FIG. 1  in another embodiment; 
         FIG. 25  is a schematic structural diagram of an electronic device in a second embodiment according to the embodiments of this disclosure; 
         FIG. 26  is a schematic diagram of an antenna architecture of the electronic device shown in  FIG. 25 ; 
         FIG. 27  is a schematic structural diagram of an electronic device in a third embodiment according to the embodiments of this disclosure; 
         FIG. 28  is a schematic diagram of an antenna architecture of the electronic device shown in  FIG. 27  in an embodiment; 
         FIG. 29  is a schematic diagram of an antenna architecture of the electronic device shown in  FIG. 27  in an embodiment; 
         FIG. 30  is a schematic structural diagram of an electronic device in a fourth embodiment according to the embodiments of this disclosure; 
         FIG. 31  is a schematic diagram of an antenna architecture of the electronic device shown in  FIG. 30 ; and 
         FIG. 32  is a schematic diagram of the antenna architecture shown in  FIG. 31  in another use state. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     The following describes the embodiments of this disclosure with reference to the accompanying drawings in the embodiments of this disclosure. 
     The embodiments of this disclosure provide an electronic device. The electronic device may be a mobile phone, a tablet personal computer, a laptop computer, a personal digital assistant (PDA), a wearable device, or the like. 
     The electronic device includes a plurality of antennas. In this disclosure, “a plurality of” means at least two. The antenna is configured to transmit and receive electromagnetic wave signals. Each antenna in the electronic device may be configured to cover one or more communication frequency bands. Different antennas may be multiplexed to improve antenna utilization. A form of the antenna may be a dipole antenna, a monopole antenna, an inverted F-shaped antenna (IFA), a patch antenna, or the like. 
     The electronic device may communicate with a network or another device by using the plurality of antennas through a wireless communications technology. The wireless communications technology includes a global system for mobile communications (GSM), a general packet radio service (GPRS), code division multiple access (CDMA), wideband code division multiple access (WCDMA), time-division code division multiple access (TD-SCDMA), long term evolution (LTE), Bluetooth (BT), a global navigation satellite system (GNSS), a wireless local area network (WLAN) (for example, a wireless fidelity (Wi-Fi) network), a near field communication (NFC) technology, frequency modulation (FM), an infrared (IR) technology, and/or the like. In this disclosure, “A and/or B” includes three cases: “A”, “B”, and “A and B”. 
       FIG. 1  is a schematic structural diagram of an electronic device in a first embodiment according to the embodiments of this disclosure,  FIG. 2  is a schematic structural diagram of the electronic device shown in  FIG. 1  in another use state, and  FIG. 3  is a schematic structural diagram of the electronic device shown in  FIG. 2  from another angle. The electronic device shown in  FIG. 1  is described by using a mobile phone as an example. 
     The electronic device  100  includes a first part  10  and a second part  20 . A plurality of antennas may be distributed in the first part  10  and the second part  20 . The first part  10  and the second part  20  can be folded relative to each other to a closed state, and can be expanded relative to each other to an open state. In other words, the first part  10  and the second part  20  can be switched between the closed state and the open state.  FIG. 1  corresponds to the open state of the electronic device  100 .  FIG. 2  and  FIG. 3  correspond to the closed state of the electronic device  100 . 
     In an embodiment, the electronic device  100  further includes a sensing apparatus  30 . The sensing apparatus  30  is located in the first part  10  and/or the second part  20 . The sensing apparatus  30  is configured to sense that the first part  10  and the second part  20  are in the closed state or the open state. The sensing apparatus  30  is electrically connected to a processor  40  of the electronic device  100 . The processor  40  is located in the first part  10  and/or the second part  20 . The processor  40  of the electronic device  100  receives a detection signal of the sensing apparatus  30 , and sends a corresponding control signal to another component of the electronic device  100  based on the signal, so that the another component of the electronic device  100  can be adjusted to a corresponding working mode in a timely manner depending on whether the first part  10  and the second part  20  are in the closed state or the open state. In this way, the electronic device  100  has higher reliability and better user experience. The sensing apparatus  30  may include one or more of a gyroscope sensor, a Hall effect sensor, or a proximity light sensor. 
     In an embodiment, there are a plurality of connection relationships between the first part  10  and the second part  20 , for example, a rotary connection, a sliding connection, and a detachable snap-fit connection. In this embodiment, an example in which the first part  10  is rotatably connected to the second part  20  is used for description. For example, the electronic device  100  further includes a rotation part  50 . The rotation part  50  connects the first part  10  and the second part  20 . The rotation part  50  can be deformed, so that the first part  10  and the second part  20  rotate relative to each other to fold or expand. As shown in  FIG. 1 , when the first part  10  and the second part  20  rotate relative to each other to expand to the open state, the rotation part  50  is located between the first part  10  and the second part  20 , and the rotation part  50  is located in a central region of the electronic device  100 . That the rotation part  50  is located in a central region of the electronic device  100  means that a central line of the rotation part  50  roughly coincides with a central line of the electronic device  100  (a slight deviation is allowed). The rotation part  50  extends in a first direction X, and the first part  10  and the second part  20  rotate relative to each other in the first direction X. In this case, as shown in  FIG. 2  and  FIG. 3 , when the first part  10  and the second part  20  are in the closed state, the first part  10  and the second part  20  overlap, and a frame  101  of the first part  10  and a frame  201  of the second part  20  totally overlap. In this case, the frame  101  of the first part  10  and the frame  201  of the second part  20  are disposed entirely opposite to each other. A frame of the electronic device  100  includes the frame  101  of the first part  10  and the frame  201  of the second part  20 . Most components of the electronic device  100  are located on an inner side of the frame of the electronic device  100 . In another embodiment, the rotation part  50  may alternatively deviate from a central region of the electronic device  100 . This embodiment is described later. 
     In an embodiment, the electronic device  100  further includes a display  60 . The display  60  is configured to display an image, a video, and the like. In this embodiment, the display  60  uses a flexible display, for example, an organic light emitting diode (OLED) display, an active-matrix organic light-emitting diode (AMOLED) display, a mini organic light-emitting diode display, a micro light-emitting diode display, a micro organic light-emitting diode display, or a quantum dot light emitting diode (QLED) display. In this case, the display  60  can be continuously located on a same side of the first part  10 , the rotation part  50 , and the second part  20 , so that when the first part  10  and the second part  20  are in the open state, the electronic device  100  has a continuous large-area display, to implement large-screen display, and when the first part  10  and the second part  20  are in the closed state, the electronic device  100  can implement display on the front, the back, and the side of the electronic device  100 . 
     In another embodiment, the display  60  may alternatively use a rigid display, for example, a liquid crystal display (LCD). In this case, the display  60  may include two display parts, and the two display parts are separately located in the first part  10  and the second part  20 . 
     In an embodiment, when the first part  10  and the second part  20  of the electronic device  100  rotate relative to each other, there may be a plurality of flip manners. For example, as shown by a solid arrow in  FIG. 1 , in one flip manner, when the first part  10  and the second part  20  are folded relative to each other, a part of the display  60  located in the first part  10  and a part of the display  60  located in the second part  20  approach each other face to face, and when the first part  10  and the second part  20  are in the closed state, the display  60  is located on an inner side of the first part  10  and the second part  20 . This flip manner is also referred to as inward folding of the display  60 . In another flip manner, as shown by a dashed arrow in  FIG. 1 , when the first part  10  and the second part  20  are folded relative to each other, a part of the display  60  located in the first part  10  and a part of the display  60  located in the second part  20  become distant from each other back to back, and when the first part  10  and the second part  20  are in the closed state, the display  60  is located on an outer side of the first part  10  and the second part  20 . This flip manner is also referred to as outward folding of the display  60 . 
     In an embodiment, the first part  10  includes a first feeding antenna  11 . The first feeding antenna  11  may have a plurality of structural forms. For example, the first feeding antenna  11  is a part of the frame  101  of the first part  10  of the electronic device  100 , or is fastened to an inner side of the frame  101  of the first part  10 . In this embodiment, an example in which the first feeding antenna  11  is a part of the frame  101  of the first part  10  is used for description. The frame  101  of the first part  10  includes at least two metal segments and at least one insulation segment for electrically isolating the at least two metal segments. The first feeding antenna  11  may be formed in one of the metal segments. In another embodiment, the first feeding antenna  11  is fastened to the inner side of the frame  101  of the first part  10 . In this case, a structural form of the first feeding antenna  11  may be a flexible circuit board, a laser direct structuring (LDS) metal, an insert molding metal, or a wire of a printed circuit board. 
     Referring to  FIG. 1 , the electronic device  100  further includes a ground plane  70 . The ground plane  70  is grounded and extends from the first part  10  to the second part  20 . In an embodiment, the ground plane  70  is a circuit board of the electronic device  100 . For example, the ground plane  70  may be a flexible circuit board, or the ground plane  70  is a flexible-rigid circuit board. In another embodiment, the ground plane  70  may be integrated into another component, for example, the display  60 , of the electronic device  100 . 
     In an embodiment, the first feeding antenna  11  is a grounded ¼ wavelength antenna. The first feeding antenna  11  may be a low-band antenna (600 MHz to 960 MHz), for example, LTE B28 (703 MHz to 803 MHz) or LTE B30 (791 MHz to 862 MHz). When the first part  10  and the second part  20  are in the open state, the first feeding antenna  11  may radiate by using a relatively long ground plane  70 , to achieve relatively high performance. 
     Referring to  FIG. 1  to  FIG. 3 , in this embodiment, after the first part  10  and the second part  20  switch from the open state to a folded state, a length of the ground plane  70  in a second direction (perpendicular to the first direction X) is reduced by approximately half, the frame  101  of the first part  10  and the frame  201  of the second part  20  overlap, space of the first feeding antenna  11  is affected, and low-frequency performance decreases greatly compared with that in the open state. 
     For example,  FIG. 4  is a reflection coefficient line graph of an example structure of the electronic device shown in  FIG. 1 , and  FIG. 5  is an efficiency line graph of an example structure of the electronic device shown in  FIG. 1 .  FIG. 4  and  FIG. 5  illustrate comparison results of the first feeding antenna  11  in two frequency bands: low-band LTE B20 (791 MHz to 862 MHz) and LTE B8 (880 MHz to 960 MHz). In  FIG. 4  and  FIG. 5 , solid lines represent performance of the first feeding antenna  11  when the first part  10  and the second part  20  are in the open state, and dotted lines represent performance of the first feeding antenna  11  when the first part  10  and the second part  20  are in the closed state. In  FIG. 4 , a horizontal coordinate represents a frequency (in a unit of GHz), and a vertical coordinate represents a reflection coefficient (in a unit of dB). In  FIG. 5 , a horizontal coordinate represents a frequency (in a unit of GHz), and a vertical coordinate represents efficiency (in a unit of dB). 
     In the example structures corresponding to  FIG. 4  and  FIG. 5 , the first feeding antenna  11  is a frame antenna in a form of an inverted F-shaped antenna. The first feeding antenna  11  is located in an upper right corner of the first part  10  that is away from the second part  20  (is located in an upper right corner of the electronic device  100  when the first part  10  and the second part  20  are in the open state). A frame thickness and width of the electronic device  100  are approximately 4 millimeters and 3 millimeters, respectively. A width of a clearance area between the frame of the electronic device  100  and the ground plane  70  is approximately 1 millimeter. A gap width between two adjacent metal segments in the frame of the electronic device  100  is approximately 1.5 millimeters. A dielectric constant and a loss angle of an insulating material used for an insulation segment between two adjacent metal segments and an insulating material filled in the clearance area between the frame of the electronic device  100  and the ground plane  70  are 3.0 and 0.01, respectively. The rotation part  50  of the first part  10  and the second part  20  is located in the central region of the electronic device  100 . When the first part  10  and the second part  20  are in the closed state, a distance between the frame  101  of the first part  10  and the frame  201  of the second part  20  in a thickness direction of the electronic device  100  is approximately 1 millimeter. 
     It can be learned from  FIG. 4  and  FIG. 5  that in a higher frequency band part (near 900 MHz) in a low frequency band, low-frequency performance of the first feeding antenna  11  in the closed state and the open state of the first part  10  and the second part  20  is similar. However, in a lower frequency band part (700 MHz to 800 MHz) in the low frequency band, low-frequency performance of the first feeding antenna  11  in the closed state of the first part  10  and the second part  20  is significantly lower than low-frequency performance of the first feeding antenna  11  in the open state of the first part  10  and the second part  20 . 
     In addition, in addition to the low frequency band, when the first feeding antenna  11  is a medium- and high-frequency antenna (1700 MHz to 2700 MHz, for example, GPS, Wi-Fi, and LTE B3, B1, and B7), performance of the first feeding antenna  11  also decreases to different extents due to a length change of the ground plane  70  and impact of overlapping of the frame  101  of the first part  10  and the frame  201  of the second part  20  when the first part  10  and the second part  20  are in the closed state. 
       FIG. 6  is a schematic diagram of an antenna architecture of the electronic device shown in  FIG. 1  in an embodiment, and  FIG. 7  is a schematic diagram of the antenna architecture shown in  FIG. 6  when an electronic device is in another use state.  FIG. 6  corresponds to a structure when the first part  10  and the second part  20  are in the open state, and  FIG. 7  corresponds to a structure when the first part  10  and the second part  20  are in the closed state. An antenna located above a dash dot line in  FIG. 6  is located in the first part  10 , and an antenna located below the dash dot line is located in the second part  20 . In  FIG. 7 , because the antennas in the first part  10  and the second part  20  overlap in the closed state, the antennas in the first part  10  and the second part  20  are illustrated through staggering, so that the antenna in the first part  10  is located on an outer side of the antenna located in the second part  20 . 
     The first part  10  includes a first feeding antenna  11 , a first feeding circuit  12 , and a first grounding circuit  13 . The first feeding circuit  12  is connected to the first feeding antenna  11 , and is configured to feed the first feeding antenna  11 . The first grounding circuit  13  is connected to the first feeding antenna  11 , and is configured to enable the first feeding antenna  11  to be grounded. For example, as shown in  FIG. 6 , the first grounding circuit  13  is connected to one end of the first feeding antenna  11 , and is configured to enable the first feeding antenna  11  to be grounded. The end of the first feeding antenna  11  that is connected to the first grounding circuit  13  is a grounding end. The other end of the first feeding antenna  11  is an ungrounded open end. A connection position of the first feeding circuit  12  on the first feeding antenna  11  is located between a connection position of the first grounding circuit  13  on the first feeding antenna  11  and the open end of the first feeding antenna  11 . In this case, an electrical length of the first feeding antenna  11  is ¼ wavelength, in other words, the first feeding antenna  11  is a ¼ wavelength antenna. 
     The second part  20  includes a first parasitic antenna  21 . When the first part  10  and the second part  20  are in the closed state, the first parasitic antenna  21  is not grounded and can be coupled to the first feeding antenna  11  to generate a first excited resonance signal through excitation. In this case, an electrical length of the first parasitic antenna  21  is ½ wavelength, in other words, the first parasitic antenna  21  is a ½ wavelength antenna. There may be one or more first excited resonance signals. 
     In an embodiment, when the first part  10  and the second part  20  are in the closed state, the first parasitic antenna  21  and the first feeding antenna  11  are at least disposed partially opposite to each other to generate a coupling capacitor between the first parasitic antenna  21  and the first feeding antenna  11 , so that the first excited resonance signal can be generated through coupling and excitation. When the first feeding antenna  11  works, radio frequency energy of the first feeding antenna  11  is transmitted to the first parasitic antenna  21  through coupling, so that an additional resonance mode is generated through excitation on the first parasitic antenna  21 , radiating frequency bandwidth of the antenna is extended, adverse impact on antenna performance that is caused by a reduction of the length of the ground plane  70  and frame overlap in the closed state is reduced, and antenna performance of the electronic device  100  is improved, that is, the electronic device  100  has relatively high antenna performance in the closed state. 
     When the first parasitic antenna  21  is not grounded, the electrical length of the first parasitic antenna  21  is ½ wavelength, and the reduction in the length of the ground plane  70  during folding has relatively weak impact on performance of the first parasitic antenna  21 , so that the first parasitic antenna  21  can maintain good radiation performance when the first part  10  and the second part  20  are in the closed state, thereby effectively extending radiating frequency bandwidth of the first feeding antenna  11 . 
     For example,  FIG. 8  is a reflection coefficient line graph of an example structure of the antenna architecture shown in  FIG. 6 ,  FIG. 9  is an efficiency line graph of an example structure of the antenna architecture shown in  FIG. 6 , and  FIG. 10  is a simulation diagram of a current and an electric field in an example structure of the antenna architecture shown in  FIG. 6 .  FIG. 8  and  FIG. 9  illustrate comparison results of the first feeding antenna  11  (¼ wavelength antenna) in two frequency bands: low-band LTE B20 (791 MHz to 862 MHz) and LTE B8 (880 MHz to 960 MHz). In  FIG. 8  and  FIG. 9 , solid lines represent performance when the first feeding antenna  11  (¼ wavelength antenna) is not coupled to the first parasitic antenna  21  and the first part  10  and the second part  20  are in the closed state, and dotted lines represent performance when the first feeding antenna  11  (¼ wavelength antenna) is coupled to the first parasitic antenna  21  (½ wavelength antenna) and the first part  10  and the second part  20  are in the closed state. In  FIG. 8 , a horizontal coordinate represents a frequency (in a unit of GHz), and a vertical coordinate represents a reflection coefficient (in a unit of dB). In  FIG. 9 , a horizontal coordinate represents a frequency (in a unit of GHz), and a vertical coordinate represents efficiency (in a unit of dB).  FIG. 10  is a simulation diagram of a current and an electric field in low-band LTE B20 (791 MHz to 862 MHz) when the first feeding antenna  11  (¼ wavelength antenna) is coupled to the first parasitic antenna  21  (½ wavelength antenna). 
     In the example structures corresponding to  FIG. 8  to  FIG. 10 , the first feeding antenna  11  is a frame antenna in a form of an inverted F-shaped antenna. The first parasitic antenna  21  is a frame antenna. When the first part  10  and the second part  20  are in the open state, the first feeding antenna  11  is located in an upper right corner of the electronic device  100 , and the first parasitic antenna  21  is located in a lower right corner of the electronic device  100 . A frame thickness and width of the electronic device  100  are approximately 4 millimeters and 3 millimeters, respectively. A width of a clearance area between the frame of the electronic device  100  and the ground plane  70  is approximately 1 millimeter. A gap width between two adjacent metal segments in the frame of the electronic device  100  is approximately 1.5 millimeters. A dielectric constant and a loss angle of an insulating material used for an insulation segment between two adjacent metal segments and an insulating material filled in the clearance area between the frame of the electronic device  100  and the ground plane  70  are 3.0 and 0.01, respectively. The rotation part  50  of the first part  10  and the second part  20  is located in the central region of the electronic device  100 . When the first part  10  and the second part  20  are in the closed state, a distance between the frame  101  of the first part  10  and the frame  201  of the second part  20  in a thickness direction of the electronic device  100  is approximately 1 millimeter. 
     It can be learned from  FIG. 8  and  FIG. 9  that, in the low frequency band, when the first feeding antenna  11  is coupled to the first parasitic antenna  21 , the first excited resonance signal generated by the first parasitic antenna  21  extends bandwidth of the first feeding antenna  11 , and reduces adverse impact on antenna performance of the first feeding antenna  11  that is caused by the reduction of the length of the ground plane  70  and frame overlap in the closed state, so that antenna performance of the first feeding antenna  11  is better. 
     In  FIG. 10 , the first to the third diagrams in the first row respectively represent a schematic diagram of a current of the first feeding antenna  11 , a schematic diagram of a current of the first parasitic antenna  21 , and a schematic diagram of an electric field when the first feeding antenna  11  is coupled to the first parasitic antenna  21  when the first part  10  and the second part  20  are in the closed state in a frequency band of 810 MHz, and the first to the third diagrams in the second row respectively represent a schematic diagram of a current of the first feeding antenna  11 , a schematic diagram of a current of the first parasitic antenna  21 , and a schematic diagram of an electric field when the first feeding antenna  11  is coupled to the first parasitic antenna  21  when the first part  10  and the second part  20  are in the closed state in a frequency band of 840 MHz. It can be learned from  FIG. 10  that a resonance of a relatively low frequency in  FIG. 8  is generated by the first feeding antenna  11 , and a resonance of a relatively high frequency is generated by the first parasitic antenna  21 , and is named the first excited resonance signal. 
     In an embodiment, the first parasitic antenna  21  may have a plurality of structural forms. For example, the first parasitic antenna  21  is a part of the frame  201  of the second part  20  of the electronic device  100 , or is fastened to an inner side of the frame  201  of the second part  20 . In this embodiment, an example in which the first parasitic antenna  21  is a part of the frame  201  of the second part  20  is used for description. The frame  201  of the first part  20  includes at least two metal segments and at least one insulation segment for electrically isolating the at least two metal segments. The first parasitic antenna  21  may be formed in one of the metal segments. In another embodiment, the first parasitic antenna  21  is fastened to the inner side of the frame  201  of the second part  20 . In this case, a structural form of the first parasitic antenna  21  may be a flexible circuit board, a laser direct structuring (LDS) metal, an insert molding metal, or a wire of a printed circuit board. 
     Further referring to  FIG. 6 , in an embodiment, a matching circuit may be further disposed between the first feeding circuit  12  and the first feeding antenna  11 , and the matching circuit is configured to match feature impedance. The matching circuit may include at least one circuit component. For example, the matching circuit may include at least one of a resistor, an inductor, or a capacitor used as lumped elements. For example, the matching circuit may include at least one of a microstrip and a strip used as distribution elements. 
     Further referring to  FIG. 6  and  FIG. 7 , in an embodiment, the second part  20  further includes a second feeding antenna  31 . The second feeding antenna  31  is electrically isolated from the first parasitic antenna  21 . When the first part  10  and the second part  20  are in the open state, the first parasitic antenna  21  can be coupled to the second feeding antenna  31  to generate a second excited resonance signal through excitation. There may be one or more second excited resonance signals. 
     In an embodiment, when the first part  10  and the second part  20  are in the open state, the first parasitic antenna  21  can be coupled to the second feeding antenna  31 , and a coupling capacitor is generated between the first parasitic antenna  21  and the second feeding antenna  31 , so that the second excited resonance signal can be generated through coupling and excitation. When the second feeding antenna  31  works, radio frequency energy of the second feeding antenna  31  is transmitted to the first parasitic antenna  21  through coupling, so that an additional resonance mode is generated through excitation on the first parasitic antenna  21 , thereby extending radiating frequency bandwidth of the antenna and improving antenna performance of the electronic device  100 . Because the first parasitic antenna  21  can be coupled to the first feeding antenna  11  when the first part  10  and the second part  20  are in the closed state, and can be coupled to the second feeding antenna  31  when the first part  10  and the second part  20  are in the open state, the electronic device  100  can multiplex the first parasitic antenna  21 , so that antenna utilization is improved. 
     In an embodiment, when the first part  10  and the second part  20  are in the open state, the first feeding antenna  11 , the second feeding antenna  31 , and the first parasitic antenna  21  are located in different corner regions of the electronic device  100 . In this case, the first feeding antenna  11  and the second feeding antenna  31  may work in close frequency bands, and the first feeding antenna  11  and the second feeding antenna  31  have relatively large space and a relatively low degree of mutual interference. The first parasitic antenna  21  may also be better separately coupled to the first feeding antenna  11  and the second feeding antenna  31  in the two states. 
     In an embodiment, the second part  20  further includes a second feeding circuit  32  and a second grounding circuit  33 . The second grounding circuit  33  is connected to one end of the second feeding antenna  31 , and is configured to enable the second feeding antenna  31  to be grounded. The end of the second feeding antenna  31  that is connected to the second grounding circuit  33  is a grounding end. The other end (that is, one end away from the grounding end) of the second feeding antenna  31  is an ungrounded open end. The second feeding circuit  32  is connected to the second feeding antenna  31 . The second feeding circuit  32  is configured to feed the second feeding antenna  31 . A connection position of the second feeding circuit  32  on the second feeding antenna  31  is located between a connection position of the second grounding circuit  33  on the second feeding antenna  31  and the open end of the second feeding antenna  31 . In this case, the second feeding antenna  31  is a grounded ¼ wavelength antenna. When the first part  10  and the second part  20  are in the open state, the first parasitic antenna  21  is grounded. In this case, an electrical length of the first parasitic antenna  21  is ¼ wavelength, in other words, the first parasitic antenna  21  is a ¼ wavelength antenna. The electrical length of the first parasitic antenna  21  is adjustable, so that there can be different electrical lengths in different use environments. 
     In an embodiment, a coupling effect between the first parasitic antenna  21  and the second feeding antenna  31  is excellent, and bandwidth of the second feeding antenna  31  can be extended to a relatively large extent. To improve the coupling effect, for example, an end of the second feeding antenna  31  that is away from the first parasitic antenna  21  is a grounding end, and an end of the second feeding antenna  31  that is close to the first parasitic antenna  21  is an open end. 
     For example,  FIG. 11  is a reflection coefficient line graph of another example structure of the antenna architecture shown in  FIG. 6 , and  FIG. 12  is an efficiency line graph of another example structure of the antenna architecture shown in  FIG. 6 .  FIG. 11  and  FIG. 12  illustrate comparison results of the second feeding antenna  31  (¼ wavelength antenna) in two frequency bands: low-band LTE B20 (791 MHz to 862 MHz) and LTE B8 (880 MHz to 960 MHz). In  FIG. 11  and  FIG. 12 , solid lines represent performance when the second feeding antenna  31  is not coupled to the first parasitic antenna  21  and the first part  10  and the second part  20  are in the open state, and dotted lines represent performance when the second feeding antenna  31  is coupled to the first parasitic antenna  21  (½ wavelength antenna) and the first part  10  and the second part  20  are in the open state. In  FIG. 11 , a horizontal coordinate represents a frequency (in a unit of GHz), and a vertical coordinate represents a reflection coefficient (in a unit of dB). In  FIG. 12 , a horizontal coordinate represents a frequency (in a unit of GHz), and a vertical coordinate represents efficiency (in a unit of dB). 
     In the example structures corresponding to  FIG. 11  and  FIG. 12 , the second feeding antenna  31  is a frame antenna in a form of an inverted F-shaped antenna. The first parasitic antenna  21  is a frame antenna. When the first part  10  and the second part  20  are in the open state, the second feeding antenna  31  is located in a lower left corner of the electronic device  100 , and the first parasitic antenna  21  is located in a lower right corner of the electronic device  100 . A frame thickness and width of the electronic device  100  are approximately 4 millimeters and 3 millimeters, respectively. A width of a clearance area between the frame of the electronic device  100  and the ground plane  70  is approximately 1 millimeter. A gap width between two adjacent metal segments in the frame of the electronic device  100  is approximately 1.5 millimeters. A dielectric constant and a loss angle of an insulating material used for an insulation segment between two adjacent metal segments and an insulating material filled in the clearance area between the frame of the electronic device  100  and the ground plane  70  are 3.0 and 0.01, respectively. The rotation part  50  of the first part  10  and the second part  20  is located in the central region of the electronic device  100 . When the first part  10  and the second part  20  are in the closed state, a distance between the frame  101  of the first part  10  and the frame  201  of the second part  20  in a thickness direction of the electronic device  100  is approximately 1 millimeter. 
     It can be learned from  FIG. 11  and  FIG. 12  that, in the low frequency band, when the second feeding antenna  31  is coupled to the first parasitic antenna  21 , the second excited resonance signal generated by the first parasitic antenna  21  extends bandwidth of the second feeding antenna  31 , so that antenna performance of the second feeding antenna  31  is better. 
     Further referring to  FIG. 6 , in an embodiment, a matching circuit may be further disposed between the second feeding circuit  32  and the second feeding antenna  31 , and the matching circuit is configured to match feature impedance. The matching circuit may include at least one circuit component. For example, the matching circuit may include at least one of a resistor, an inductor, or a capacitor used as lumped elements. For example, the matching circuit may include at least one of a microstrip and a strip used as distribution elements. 
     It may be understood that when a parasitic antenna is not grounded, an electrical length of the parasitic antenna is N/2 wavelength, where N is a positive integer. When a parasitic antenna is grounded, an electrical length of the parasitic antenna is M/4 wavelength, where M is a positive odd number. 
     In another embodiment, when the first part  10  and the second part  20  are in the open state, the first parasitic antenna  21  may also be grounded (in other words, the first parasitic antenna  21  is a ½ wavelength antenna). In this case, a coupling effect between the first parasitic antenna  21  and the second feeding antenna  31  is poorer than that in the foregoing embodiment, but bandwidth of the second feeding antenna  31  can still be extended. 
     In an embodiment, as shown in  FIG. 6 , the second part  20  further includes a switching circuit  22 . One end of the switching circuit  22  is connected to the first parasitic antenna  21 , and the other end is grounded. The switching circuit  22  is configured to connect the first parasitic antenna  21  to the ground or disconnect the first parasitic antenna  21  from the ground, so that the electrical length of the first parasitic antenna  21  is adjustable. For example, the switching circuit  22  is configured to disconnect the first parasitic antenna  21  from the ground when the first part  10  and the second part  20  are in the closed state. In this case, the electrical length of the first parasitic antenna  21  is ½ wavelength. The switching circuit  22  is further configured to connect the first parasitic antenna  21  to the ground when the first part  10  and the second part  20  are in the open state. In this case, the electrical length of the first parasitic antenna  21  is ¼ wavelength. 
     In this embodiment, by disposing the switching circuit  22 , the electrical length of the first parasitic antenna  21  is adjustable, and the first parasitic antenna  21  can implement different coupling functions when the electronic device  100  is in different use states, so that the antenna is multiplexed. 
     For example, the switching circuit  22  may include a tuning switch  221 . The switching circuit  22  switches a connection relationship between the first parasitic antenna  21  and the ground by switching the tuning switch  221  between a closed state and an open state, so that the electrical length of the first parasitic antenna  21  is adjustable. For example, the tuning switch  221  may be roughly connected to a middle part of the first parasitic antenna  21 . In an embodiment, a middle part of an antenna includes a central location and another location that slightly deviates from the central location, and the middle part of the antenna is located between both ends of the antenna. The middle part of the first parasitic antenna  21  is located between both ends of the first parasitic antenna  21 . 
     For another example, the switching circuit  22  may include a tuning switch, a first matching branch, and a second matching branch. The first matching branch is different from the second matching branch. A control end of the tuning switch is connected to the first parasitic antenna  21 , and two selection ends of the tuning switch are connected to the first matching branch and the second matching branch. The switching circuit  22  switches a connection relationship between the first parasitic antenna  21  and the ground by switching a connection between the first matching branch and the second matching branch by using the control end of the tuning switch, so that the electrical length of the first parasitic antenna  21  is adjustable. 
     The tuning switch  221  of the switching circuit  22  is electrically connected to the processor  40 . The processor  40  controls a switching status of the tuning switch  221  based on a sensing signal of the sensing apparatus  30 , so that the switching circuit  22  can accurately adjust the electrical length of the first parasitic antenna  21  based on a status of the first part  10  and the second part  20 . In this way, antenna performance of the electronic device  100  is more reliable. 
     In an embodiment, as shown in  FIG. 6 , the first part  10  further includes a second parasitic antenna  41 . When the first part  10  and the second part  20  are in the closed state, the second parasitic antenna  41  is not grounded and can be coupled to the second feeding antenna  31  to generate a third excited resonance signal through excitation. In this case, the second parasitic antenna  41  is a ½ wavelength antenna. When the first part  10  and the second part  20  are in the open state, the second parasitic antenna  41  may be located in an upper left corner of the electronic device  100 . The second parasitic antenna  41 , the first feeding antenna  11 , the second feeding antenna  31 , and the first parasitic antenna  21  are located in different corner regions of the electronic device  100 . When the first part  10  and the second part  20  are in the open state, the second parasitic antenna  41  can be coupled to the first feeding antenna  11  to generate a fourth excited resonance signal through excitation. In this case, the second parasitic antenna  41  may be grounded. For structural design of the second parasitic antenna  41 , refer to the first parasitic antenna  21 . For example, the first part  10  may also include a switching circuit (refer to the switching circuit  22 ) connected between the second parasitic antenna  41  and the ground. In another embodiment, when the first part  10  and the second part  20  are in the open state, the second parasitic antenna  41  may be ungrounded and coupled to the first feeding antenna  11 . 
     In an embodiment, in the antenna architecture shown in  FIG. 6 , the switching circuit  22  and a physical length of a metal segment in which the first parasitic antenna  21  is located may be designed, so that the first parasitic antenna  21  is switched between a grounded state and an ungrounded state, in other words, the electrical length of the first parasitic antenna  21  is switched between ½ wavelength and ¼ wavelength. When the foregoing design is difficult to meet an adjustment requirement of the electrical length of the first parasitic antenna  21 , one or more tuning circuits may be connected to the first parasitic antenna  21 , so that the electrical length of the first parasitic antenna  21  meets the adjustment requirement through coordination of the one or more tuning circuits. 
     For example,  FIG. 13  is a schematic diagram of an antenna architecture of the electronic device shown in  FIG. 1  in another embodiment. Most technical content of the antenna architecture shown in this embodiment that is the same as that of the antenna architecture shown in the foregoing embodiment is not described again. 
     The second part  20  further includes one or more first tuning circuits  23 . The one or more first tuning circuits  23  are connected to the first parasitic antenna  21 . The first tuning circuit  23  is configured to adjust the electrical length of the first parasitic antenna  21 . The one or more first tuning circuits  23  may be connected to an end of the first parasitic antenna  21 , to better perform a tuning function. For example, the second part  20  includes two first tuning circuits  23 , and the two first tuning circuits  23  are separately connected to both ends of the first parasitic antenna  21 . Certainly, in another embodiment, a connection position of the one or more first tuning circuits  23  on the first parasitic antenna  21  may be in another manner. This is not strictly limited in this disclosure. 
     The first tuning circuit  23  may include one or more of a switch, a capacitor, an inductor, or a low-pass high-cut filter. A specific structure of the first tuning circuit  23  is not strictly limited in this disclosure. 
       FIG. 14  is a schematic diagram of an antenna architecture of the electronic device shown in  FIG. 1  in another embodiment. Most technical content of the antenna architecture shown in this embodiment that is the same as that of the antenna architecture shown in the foregoing embodiment is not described again. 
     In an embodiment, the second feeding antenna  31  is located in a side edge region, instead of a corner region, of the second part  20 , and when the first part  10  and the second part  20  are in the closed state, the second parasitic antenna  41  located in the corner region can also be coupled to the second feeding antenna  31 . In an embodiment, because the second feeding antenna  31  is relatively away from the first parasitic antenna  21 , the second feeding antenna  31  is no longer coupled to the first parasitic antenna  21 . 
     Similarly, in some examples, the first feeding antenna  11  may also be located in a side edge region of the first part  10 . When the first part  10  and the second part  20  are in the closed state, the first parasitic antenna  21  located in a corner region can be coupled to the first feeding antenna  11 . The first feeding antenna  11  is no longer coupled to the second parasitic antenna  41 . In this example, when the first part  10  and the second part  20  are in the open state, the first feeding antenna  11  and the second feeding antenna  31  may be located on both sides of the electronic device  100 , so that both the first feeding antenna  11  and the second feeding antenna  31  have relatively sufficient radiation space. 
       FIG. 15  is a schematic diagram of an antenna architecture of the electronic device shown in  FIG. 1  in another embodiment. Most technical content of the antenna architecture shown in this embodiment that is the same as that of the antenna architecture shown in the foregoing embodiment is not described again. 
     The second part  20  further includes a third feeding circuit  52  and a first filter circuit  53 . The third feeding circuit  52  and the first filter circuit  53  are connected to different locations of the first parasitic antenna  21 , and are configured to form a third feeding antenna  51  on the first parasitic antenna  21 . A radiating frequency band of the third feeding antenna  51  is different from a radiating frequency band of the first feeding antenna  11 . For example, the first feeding antenna  11  is a low-band antenna. The radiating frequency band of the third feeding antenna  51  is a wireless local area network antenna, a short-range wireless communications antenna, a medium- and high-band antenna, a sub 6G antenna (a frequency is less than 6 GHz), a wireless charging antenna, or the like. In this case, the first filter circuit  53  has a low-cut and high-pass feature. For example, the first filter circuit  53  includes a high-pass low-cut filter  531 . 
     In this case, the third feeding antenna  51  and the first parasitic antenna  21  share a same segment of radiator, so that antenna utilization can be improved. In addition, because the radiating frequency band of the third feeding antenna  51  is different from the radiating frequency band of the first feeding antenna  11 , the third feeding antenna  51  and the first feeding antenna  11  do not interfere with each other, and are well isolated. 
     Connection positions of the third feeding circuit  52  and the first filter circuit  53  on the first parasitic antenna  21  may be located between a connection position of the switching circuit  22  on the first parasitic antenna  21  and one end of the first parasitic antenna  21 . For example, the first filter circuit  53  is closer to the middle part of the first parasitic antenna  21  than to an end of the first parasitic antenna  21 . The connection position of the third feeding circuit  52  on the first parasitic antenna  21  is located between the connection position of the first filter circuit  53  on the first parasitic antenna  21  and an end of the first parasitic antenna  21 . 
     For example,  FIG. 16  is a schematic diagram of an antenna architecture of the electronic device shown in  FIG. 1  in another embodiment. Most technical content of the antenna architecture shown in this embodiment that is the same as that of the antenna architecture shown in the foregoing embodiment is not described again. 
     The electronic device  100  further includes a fourth feeding antenna  81 , a fourth feeding circuit  82 , and a second filter circuit  83 . The fourth feeding antenna  81  is adjacent to and electrically isolated from the first parasitic antenna  21 . The fourth feeding circuit  82  is connected to the fourth feeding antenna  81 . The fourth feeding circuit  82  is configured to feed the fourth feeding antenna  81 . The second filter circuit  83  is connected to the first parasitic antenna  21 . A radiating frequency band of the fourth feeding antenna  81  is different from the radiating frequency band of the first feeding antenna  11 . For example, the first feeding antenna  11  is a low-band antenna. The radiating frequency band of the fourth feeding antenna  81  is a wireless local area network antenna, a short-range wireless communications antenna, a medium- and high-band antenna, a wireless charging antenna, or the like. In this case, the second filter circuit  83  has a low-cut and high-pass feature. For example, the second filter circuit  83  includes a high-pass low-cut filter  831 . 
     In this case, a radiator part in which the first parasitic antenna  21  is located is used as a parasitic branch of the fourth feeding antenna  81  to implement multiplexing, so that antenna utilization can be improved. In addition, because the radiating frequency band of the fourth feeding antenna  81  is different from the radiating frequency band of the first feeding antenna  11 , the fourth feeding antenna  81  and the first feeding antenna  11  do not interfere with each other, and are well isolated. 
     The fourth feeding antenna  81  may be located in the first part  10  or the second part  20 . A connection position of the fourth feeding antenna  81  on the first parasitic antenna  21  is located between the connection position of the switching circuit  22  on the first parasitic antenna  21  and the fourth feeding antenna  81 . 
     In another embodiment, the antenna architecture may further include more feeding antennas. These feeding antennas may use different radiators from the first feeding antenna  11 , the first parasitic antenna  21 , the second feeding antenna  31 , the second parasitic antenna  22 , and the like, or a same radiator may be multiplexed. This is not strictly limited in this disclosure. 
       FIG. 17  is a schematic diagram of an antenna architecture of the electronic device shown in  FIG. 1  in another embodiment, and  FIG. 18  is a schematic diagram of the antenna architecture shown in  FIG. 17  in another use state.  FIG. 17  corresponds to the open state of the first part  10  and the second part  20 .  FIG. 18  corresponds to the closed state of the first part  10  and the second part  20 . In  FIG. 18 , because the antennas in the first part  10  and the second part  20  overlap in the closed state, the antennas in the first part  10  and the second part  20  are illustrated through staggering, so that the antenna in the first part  10  is located on an outer side of the antenna located in the second part  20 . Most technical content of the antenna architecture shown in this embodiment that is the same as that of the antenna architecture shown in the foregoing embodiment is not described again. 
     The second part  20  includes a second feeding antenna  31 , a second feeding circuit  32 , and a second grounding circuit  33 . The second feeding antenna  31  is electrically isolated from the first parasitic antenna  21 . The second grounding circuit  33  is connected to a middle part of the second feeding antenna  31 . Both ends of the second feeding antenna  31  are ungrounded open ends. The second feeding circuit  32  is connected to the second feeding antenna  31 , and is configured to feed the second feeding antenna  31 . A connection position of the second feeding circuit  32  on the second feeding antenna  31  is located between a connection position of the second grounding circuit  33  on the second feeding antenna  31  and an end of the second feeding antenna  31 . In this case, the second feeding antenna  31  is a ½ wavelength antenna. The first parasitic antenna  21  is a floating antenna (floating antenna). In other words, the first parasitic antenna  21  is not grounded. 
     In an embodiment, when the first part  10  and the second part  20  are in the open state, the second feeding antenna  31  has two antenna modes, has relatively large bandwidth, and has relatively high antenna performance. Therefore, the second feeding antenna  31  may not be coupled to the first parasitic antenna  21 . When the first part  10  and the second part  20  are in the closed state, the first feeding antenna  11  is coupled to the first parasitic antenna  21  of ½ wavelength, to improve antenna performance of the first feeding antenna  11  and reduce adverse impact of an external environment. In this case, for the antenna architecture, there is no need to switch between different antenna coupling forms when the first part  10  and the second part  20  are in different states, in other words, the first parasitic antenna  21  may be a single ½ wavelength antenna, and no switching circuit  22  needs to be disposed, so that a structure of the antenna architecture is simpler. 
     For example,  FIG. 19  is a reflection coefficient line graph of the second feeding antenna  31  in an example structure of the antenna architecture shown in  FIG. 17 ,  FIG. 20  is an efficiency line graph of the second feeding antenna  31  in an example structure of the antenna architecture shown in  FIG. 17 , and  FIG. 21  is a simulation diagram of a current, an electric field, and a radiation direction of the second feeding antenna  31  in an example structure of the antenna architecture shown in  FIG. 17 .  FIG. 19  to  FIG. 21  correspond to an example structure when the first part  10  and the second part  20  are in the open state and the second feeding antenna  31  is not coupled to the first parasitic antenna  21 . In  FIG. 20 , a horizontal coordinate represents a frequency (in a unit of GHz), and a vertical coordinate represents a reflection coefficient (in a unit of dB). In  FIG. 21 , a horizontal coordinate represents a frequency (in a unit of GHz), and a vertical coordinate represents efficiency (in a unit of dB).  FIG. 21  corresponds to simulation diagrams of the second feeding antenna  31  respectively at 890 MHz and 960 MHz. 
     In the example structure corresponding to  FIG. 19  to  FIG. 21 , the second feeding antenna  31  is a ½ wavelength antenna. The second feeding antenna  31  is a frame antenna. A frame thickness and width of the electronic device  100  are approximately 4 millimeters and 3 millimeters, respectively. A width of a clearance area between the frame of the electronic device  100  and the ground plane  70  is approximately 1 millimeter. A gap width between two adjacent metal segments in the frame of the electronic device  100  is approximately 1.5 millimeters. A dielectric constant and a loss angle of an insulating material used for an insulation segment between two adjacent metal segments and an insulating material filled in the clearance area between the frame of the electronic device  100  and the ground plane  70  are 3.0 and 0.01, respectively. 
     It can be learned from  FIG. 19  to  FIG. 21  that when the second feeding antenna  31  is a ½ wavelength antenna, the second feeding antenna  31  has two antenna modes, relatively large bandwidth, and relatively high antenna performance. 
     It may be understood that, in some embodiments, the second feeding antenna  31  may also be coupled to the first parasitic antenna  21 . In this case, although a switching circuit (refer to the switching circuit  22 ) needs to be disposed on the first parasitic antenna  21 , antenna performance of the second feeding antenna  31  when the first part  10  and the second part  20  are in the open state is also improved to some extent. 
     In an embodiment, as shown in  FIG. 17 , the first feeding antenna  11  may be a ½ wavelength antenna. For antenna performance of the first feeding antenna  11  when the first part  10  and the second part  20  are in the open state, refer to the second feeding antenna  31 . 
     In this case, when the first part  10  and the second part  20  are in the open state, the first feeding antenna  11  and the second feeding antenna  31  may be separately located in two diagonally disposed corner regions of the electronic device  100 . The first parasitic antenna  21  and the second parasitic antenna  41  of the electronic device  100  may be located in the other two diagonally disposed corner regions of the electronic device  100 . 
     For example,  FIG. 22  is a reflection coefficient line graph of an example structure of the antenna architecture shown in  FIG. 17 , and  FIG. 23  is an efficiency line graph of an example structure of the antenna architecture shown in  FIG. 17 . In  FIG. 22  and  FIG. 23 , solid lines represent performance when the first feeding antenna  11  (½ wavelength antenna) is coupled to the first parasitic antenna  21  with an electrical length of ½ wavelength and the first part  10  and the second part  20  are in the closed state, dotted lines represent performance when the first feeding antenna  11  (½ wavelength antenna) is coupled to the first parasitic antenna  21  with an electrical length of ¼ wavelength and the first part  10  and the second part  20  are in the closed state, and dash dot lines represent performance when the first feeding antenna  11  (½ wavelength antenna) is not coupled to the first parasitic antenna  21  and the first part  10  and the second part  20  are in the open state. In  FIG. 22 , a horizontal coordinate represents a frequency (in a unit of GHz), and a vertical coordinate represents a reflection coefficient (in a unit of dB). In  FIG. 23 , a horizontal coordinate represents a frequency (in a unit of GHz), and a vertical coordinate represents efficiency (in a unit of dB). 
     In the example structure corresponding to  FIG. 22  and  FIG. 23 , the first feeding antenna  11  is a frame antenna. The first parasitic antenna  21  is a frame antenna. When the first part  10  and the second part  20  are in the open state, the first feeding antenna  11  is located in an upper right corner of the electronic device  100 , and the first parasitic antenna  21  is located in a lower right corner of the electronic device  100 . A frame thickness and width of the electronic device  100  are approximately 4 millimeters and 3 millimeters, respectively. A width of a clearance area between the frame of the electronic device  100  and the ground plane  70  is approximately 1 millimeter. A gap width between two adjacent metal segments in the frame of the electronic device  100  is approximately 1.5 millimeters. A dielectric constant and a loss angle of an insulating material used for an insulation segment between two adjacent metal segments and an insulating material filled in the clearance area between the frame of the electronic device  100  and the ground plane  70  are 3.0 and 0.01, respectively. The rotation part  50  of the first part  10  and the second part  20  is located in the central region of the electronic device  100 . When the first part  10  and the second part  20  are in the closed state, a distance between the frame  101  of the first part  10  and the frame  201  of the second part  20  in a thickness direction of the electronic device  100  is approximately 1 millimeter. 
     It can be learned from  FIG. 22  and  FIG. 23  that when the first feeding antenna  11  is coupled to the first parasitic antenna  21 , the first excited resonance signal generated by the first parasitic antenna  21  through coupling and excitation is generated at a highest resonance. Antenna performance of the first feeding antenna  11  when the first part  10  and the second part  20  are in the closed state and the first feeding antenna  11  is coupled to the first parasitic antenna  21  with an electrical length of ½ wavelength is slightly lower than antenna performance when the first part  10  and the second part  20  are in the open state, but higher than antenna performance when the first part  10  and the second part  20  are in the closed state and the first feeding antenna  11  is coupled to the first parasitic antenna  21  with an electrical length of ¼ wavelength. 
     In an embodiment, the electronic device  100  further includes one or more second tuning circuits (not shown). The one or more second tuning circuits are connected to the first parasitic antenna  21 , and are configured to adjust a frequency band of an excited resonance of the first parasitic antenna  21 , so that when the first feeding antenna  11  is coupled to the first parasitic antenna  21 , better antenna performance can be obtained. Certainly, in another embodiment, a physical length of the first parasitic antenna  21  is adjusted synchronously or separately, so that when the first feeding antenna  11  is coupled to the first parasitic antenna  21 , better antenna performance can be obtained. 
     In an embodiment, further referring to  FIG. 17  and  FIG. 18 , the electronic device  100  further includes a fifth feeding antenna  61 , a fifth feeding circuit  62 , a fifth grounding circuit  63 , and a third parasitic antenna  71 . The fifth feeding antenna  61  is located in the second part  20 , and the third parasitic antenna  71  is located in the first part  10  (in another embodiment, the fifth feeding antenna  61  may be located in the first part  10 , and the third parasitic antenna  71  may be located in the second part  20 ). The fifth feeding antenna  61  is electrically isolated from the first parasitic antenna  21  and the second feeding antenna  31 . The fifth feeding circuit  62  is connected to the fifth feeding antenna  61 , and is configured to feed the fifth feeding antenna  61 . The fifth grounding circuit  63  is connected to the fifth feeding antenna  61 , and is configured to enable the fifth feeding antenna  61  to be grounded. When the first part  10  and the second part  20  are in the closed state, the third parasitic antenna  71  is not grounded and can be coupled to the fifth feeding antenna  61  to generate a fifth excited resonance signal through excitation. In this case, an electrical length of the third parasitic antenna  71  is ½ wavelength, in other words, the third parasitic antenna  71  is a ½ wavelength antenna. In this embodiment, the fifth feeding antenna  61  may be configured to radiate a medium- and high-frequency signal. 
       FIG. 24  is a schematic diagram of an antenna architecture of the electronic device shown in  FIG. 1  in another embodiment.  FIG. 24  corresponds to the open state of the first part  10  and the second part  20 . Most technical content of the antenna architecture shown in this embodiment that is the same as that of the antenna architecture shown in the foregoing embodiment is not described again. 
     In an embodiment, the second feeding antenna  31  is located in the first part  10  instead of the second part  20 . Specifically, the first part  10  further includes the second feeding antenna  31 , and the second feeding antenna  31  is electrically isolated from the first feeding antenna  11 . In this case, the second parasitic antenna  41  is located in the second part  20  instead of the first part  10 , so that when the first part  10  and the second part  20  are in the closed state, the second parasitic antenna  41  can be coupled to the second feeding antenna  31 . 
     The first feeding antenna  11  and the second feeding antenna  31  are disposed as far as possible away from each other, so that both the first feeding antenna  11  and the second feeding antenna  31  have relatively sufficient radiation space. 
     In this disclosure, the first feeding antenna  11 , the first parasitic antenna  21 , the second feeding antenna  31 , and the second parasitic antenna  41  may be arranged in a plurality of manners, provided that when the first part  10  and the second part  20  are in the closed state, the first feeding antenna  11  is coupled to the first parasitic antenna  21 , and the second feeding antenna  31  is coupled to the second parasitic antenna  41 . This is not strictly limited in this disclosure. 
       FIG. 25  is a schematic structural diagram of an electronic device in a second embodiment according to the embodiments of this disclosure, and  FIG. 26  is a schematic diagram of an antenna architecture of the electronic device shown in  FIG. 25 . Most technical content of the electronic device  100  shown in the second embodiment that is the same as that of the electronic device  100  shown in the first embodiment is not described again. 
     In the second embodiment, the rotation part  50  deviates from the central region of the electronic device  100  instead of being located in the central region of the electronic device  100 . Specifically, the electronic device  100  further includes the rotation part  50 , the rotation part  50  connects the first part  10  and the second part  20 , and the rotation part  50  can be deformed, so that the first part  10  and the second part  20  rotate relative to each other to fold or expand. The rotation part  50  deviates from the central region of the electronic device  100 . In this case, a deviation between the center line of the rotation part  50  and the center line of the electronic device  100  is relatively large. When the first part  10  and the second part  20  are in the closed state, an end of one of the first part  10  and the second part  20  protrudes relative to the other part. For example, in this embodiment, the rotation part  50  extends in the first direction X. In the second direction perpendicular to the first direction X, a length of the second part  20  is greater than a length of the first part  10 , and when the first part  10  and the second part  20  are in the closed state, an end of the second part  20  that is away from the first part  10  protrudes relative to the first part  10 . When the first part  10  and the second part  20  are in the closed state, the frame  101  of the first part  10  and the frame  201  of the second part  20  partially overlap. In other words, the frame  101  of the first part  10  and the frame  201  of the second part  20  are disposed partially opposite to each other. 
     When the first part  10  and the second part  20  are in the open state, the electronic device  100  includes two side edges  1001  spanning the rotation part  50 . The two side edges  1001  extend in the first direction X. The first feeding antenna  11  and the first parasitic antenna  21  are located on a same side edge  1001 . In this case, when the first part  10  and the second part  20  are in the closed state, the first feeding antenna  11  and the first parasitic antenna  21  can be coupled to each other. The second feeding antenna  31  and the first feeding antenna  11  are located on different side edges  1001 . In this case, both the first feeding antenna  11  and the second feeding antenna  31  have relatively large radiation space. 
     The first parasitic antenna  21  may extend from a side edge  1001  of the electronic device  100  to another edge  1002  of the electronic device  100  along an edge of a corner region. The second parasitic antenna  41  may extend from the other side edge  1001  of the electronic device  100  to another edge  1003  of the electronic device  100  along another corner region. 
       FIG. 27  is a schematic structural diagram of an electronic device in a third embodiment according to the embodiments of this disclosure. Most technical content of the electronic device  100  shown in the third embodiment that is the same as that of the electronic device  100  described above is not described again. 
     Sizes of the first part  10  and the second part  20  in this embodiment are slightly different from sizes of the first part  10  and the second part  20  in the foregoing embodiments. In this embodiment, the rotation part  50  extends in the second direction Y. A conventional flip manner of the first part  10  and the second part  20  in this embodiment is flipping left or right, and a conventional flip manner in the foregoing embodiments is flipping upward or downward. The conventional flip manner of the first part  10  and the second part  20  of the electronic device  100  corresponds to disposing locations of some components in the electronic device  100 , for example, a location of an earpiece, a location of a front-facing camera, and the like. 
       FIG. 28  is a schematic diagram of an antenna architecture of the electronic device shown in  FIG. 27  in an embodiment. 
     The first part  10  includes a first feeding antenna  11  and a second parasitic antenna  41 . The second part  20  includes a second feeding antenna  31  and a first parasitic antenna  21 . When the first part  10  and the second part  20  are in the open state, the first feeding antenna  11 , the second parasitic antenna  41 , the second feeding antenna  31 , and the first parasitic antenna  21  are separately located in four corner regions of the electronic device  100 . When the first part  10  and the second part  20  are in the closed state, the first feeding antenna  11  is coupled to the first parasitic antenna  21  with an electrical length of ½ wavelength, and the second feeding antenna  31  is coupled to the second parasitic antenna  41  with an electrical length of ½ wavelength. 
     In an embodiment, the first feeding antenna  11  and the second feeding antenna  31  are ½ wavelength antennas, and the first parasitic antenna  21  and the second parasitic antenna  41  are ½ wavelength floating antennas. 
     In another embodiment, the first feeding antenna  11  and the second feeding antenna  31  may be alternatively ¼ wavelength antennas. In this case, a switching circuit (refer to the switching circuit  22 ) is connected to each of the first parasitic antenna  21  and the second parasitic antenna  41 , and the switching circuit is configured to switch an electrical length of the antenna. 
       FIG. 29  is a schematic diagram of an antenna architecture of the electronic device shown in  FIG. 27  in another embodiment. 
     The first part  10  includes a first feeding antenna  11  and a second feeding antenna  31 . The second part  20  includes a first parasitic antenna  21  and a second parasitic antenna  41 . When the first part  10  and the second part  20  are in the open state, the first feeding antenna  11 , the second parasitic antenna  41 , the second feeding antenna  31 , and the first parasitic antenna  21  are separately located in four corner regions of the electronic device  100 . When the first part  10  and the second part  20  are in the closed state, the first feeding antenna  11  is coupled to the first parasitic antenna  21  with an electrical length of ½ wavelength, and the second feeding antenna  31  is coupled to the second parasitic antenna  41  with an electrical length of ½ wavelength. 
     In an embodiment, the first feeding antenna  11  and the second feeding antenna  31  are ¼ wavelength antennas. A switching circuit (refer to the switching circuit  22 ) is connected to each of the first parasitic antenna  21  and the second parasitic antenna  41 , and the switching circuit is configured to switch an electrical length of the antenna. 
     In another embodiment, the first feeding antenna  11  and the second feeding antenna  31  may be alternatively ½ wavelength antennas, and in this case, the first parasitic antenna  21  and the second parasitic antenna  41  are ½ wavelength floating antennas. 
     In the foregoing embodiments, the first part  10  and the second part  20  are switched between the open state and the closed state through relative rotation. In another embodiment, the first part  10  and the second part  20  may be alternatively switched between the open state and the closed state through relative sliding. An example is as follows: 
       FIG. 30  is a schematic structural diagram of an electronic device in a fourth embodiment according to the embodiments of this disclosure. Most technical content of the electronic device  100  shown in the third embodiment that is the same as that of the electronic device  100  described above is not described again. 
     The electronic device  100  includes a first part  10  and a second part  20 . The first part  10  is slidably connected to the second part  20 . When sliding relative to each other, the first part  10  and the second part  20  can be folded relative to each other to a closed state, and can be expanded relative to each other to an open state. When the first part  10  and the second part  20  are in the closed state, the first part  10  and the second part  20  are vertically stacked. When the first part  10  and the second part  20  are in the open state, a small portion of the first part  10  and a small portion of the second part  20  remain in a stacked state, and most of the first part  10  and most of the second part  20  are in a staggered state, namely, an expanded state. In an embodiment, when the first part  10  and the second part  20  are in the open state, the first part  10  and the second part  20  may be totally staggered. 
     In an embodiment, an example in which the first part  10  is located above the second part  20  is used for description. In another embodiment, the first part  10  may be alternatively located below the second part  20 . 
       FIG. 31  is a schematic diagram of an antenna architecture of the electronic device shown in  FIG. 30 , and  FIG. 32  is a schematic diagram of the antenna architecture shown in  FIG. 31  in another use state.  FIG. 31  corresponds to a structure when the first part  10  and the second part  20  are in the open state.  FIG. 32  corresponds to a structure when the first part  10  and the second part  20  are in the closed state. In  FIG. 32 , because antennas in the first part  10  and the second part  20  overlap in the closed state, the antennas in the first part  10  and the second part  20  are illustrated through staggering, so that the antenna in the first part  10  is located on an outer side of the antenna located in the second part  20 . 
     The first part  10  includes a first feeding antenna  11 , and the second part  20  includes a first parasitic antenna  21 . When the first part  10  and the second part  20  are in the closed state, the first parasitic antenna  21  is not grounded and can be coupled to the first feeding antenna  11  to generate a first excited resonance signal through excitation. In this case, an electrical length of the first parasitic antenna  21  is ½ wavelength, in other words, the first parasitic antenna  21  is a ½ wavelength antenna. 
     The second part  20  further includes a second feeding antenna  31 . When the first part  10  and the second part  20  are in the closed state, the first feeding antenna  11  and the second feeding antenna  31  are separately located in two diagonally disposed corner regions of the electronic device  100 . In this case, both the first feeding antenna  11  and the second feeding antenna  31  have relatively sufficient radiation space. 
     The first part  10  may further include a second parasitic antenna  41 . When the first part  10  and the second part  20  are in the closed state, the second parasitic antenna  41  is not grounded and can be coupled to the second feeding antenna  31  to generate a third excited resonance signal through excitation. In this case, an electrical length of the second parasitic antenna  41  is ½ wavelength, in other words, the second parasitic antenna  41  is a ½ wavelength antenna. 
     In another embodiment, the second feeding antenna  31  may be alternatively located in the first part  10 . The second feeding antenna  31  and the first feeding antenna  11  are electrically isolated, and are separately located in corner regions of two diagonal angles of the first part  10 . In this case, the second parasitic antenna  41  is located in the first part  10 . 
     In another embodiment, the first part  10  and the second part  20  may be alternatively switched between the open state and the closed state in another manner (for example, a detachable snap-fit manner). This may be specifically determined based on an actual requirement, and is not limited in this embodiment of this disclosure. 
     The foregoing descriptions are merely specific embodiments of this disclosure, but are not intended to limit the protection scope of this disclosure. Any variation or replacement readily figured out by a person skilled in the art within the technical scope disclosed in this disclosure shall fall within the protection scope of this disclosure. If there is no conflict, the embodiments of this disclosure and the features in the embodiments may be combined with each other. Therefore, the protection scope of this disclosure shall be subject to the protection scope of the claims.