A foldable electronic device

Abstract

The application provides a foldable electronic device, comprising a first main body, a second main body and an antenna, the antenna comprising a main antenna unit and a parasitic antenna unit, the main antenna unit being arranged on the first main body, and the parasitic antenna unit being arranged on the second main body, the main antenna unit comprising a first radiation branch and a second radiation branch, and the parasitic antenna unit comprising a third radiation branch and a fourth radiation branch, when the electronic device is in a folded state, the first radiation branch and the third radiation branch are located at the side, and the second radiation branch and the fourth radiation branch are located at the bottom; when the first radiation branch is the main radiator of the main antenna unit, the fourth radiation branch is the main radiator of the parasitic antenna unit, or when the second radiation branch is the main radiator of the main antenna unit, the third radiation branch is the main radiator of the parasitic antenna unit, so that the main radiator of the main antenna unit is far away from the cavity mode, the excitation of the cavity mode is weakened, and the cavity mode is suppressed through the parasitic antenna unit, and the cavity clutter is eliminated.

Description

TECHNICAL FIELD

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

[0002] The folding electronic device comprises a shell, a folding device, an antenna and a flexible screen. The antenna is arranged on a metal frame of the shell. The folding assembly is located between the two shells. Meanwhile, the flexible screen is mounted on the shell. When the two shells are unfolded under the driving of the folding assembly, the flexible screen is unfolded, so that the electronic device is in an unfolded state. In the unfolded state, the display screen of the electronic device is larger, which can improve the user experience. When the two shells are folded under the driving of the folding assembly, the flexible screen can be folded. In the folded state, a cavity is formed between the flexible screens. The cavity causes the antenna to generate clutter, which affects the performance of the antenna. SUMMARY

[0003] The folding electronic device provided by the embodiment of the present application comprises a first main body, a second main body and an antenna. The first main body and the second main body are connected through a folding device, so that the first main body and the second main body can rotate relative to each other. The antenna comprises a main antenna unit and a parasitic antenna unit. The main antenna unit is arranged on the first main body, and the parasitic antenna unit is arranged on the second main body. The main antenna unit comprises a first radiation branch and a second radiation branch. The parasitic radiation unit comprises a third radiation branch and a fourth radiation branch. When the folding electronic device is in a folded state, the first radiation branch and the third radiation branch are arranged opposite to each other and spaced from each other, and the first radiation branch and the third radiation branch are located on the side of the folding electronic device. The second radiation branch and the fourth radiation branch are arranged opposite to each other and spaced from each other, and the second radiation branch and the fourth radiation branch are located on the bottom of the folding electronic device. When the first radiation branch is the main radiator of the main antenna unit, the fourth radiation branch is the main radiator of the parasitic antenna unit. Alternatively, when the second radiation branch is the main radiator of the main antenna unit, the third radiation branch is the main radiator of the parasitic antenna unit.

[0004] In the embodiment of the present application, the main radiator of the main antenna unit and the main radiator of the parasitic antenna unit are staggered with each other. The main radiator of the main antenna unit is far away from the mode of the cavity, so as to weaken the excitation of the main antenna unit to the mode of the cavity. The current direction of the mode of the cavity is the same as the current direction of the main radiator of the parasitic antenna unit, and the two are conjugate modes. Therefore, the mode of the cavity is suppressed through the parasitic antenna unit, so as to weaken or cancel the mode of the cavity, thereby eliminating the cavity clutter.

[0005] When the energy of the spurious wave is concentrated on the side of the cavity, the first step to eliminate the spurious wave is to concentrate the energy of the main antenna unit on the second radiation branch far from the side, i.e. to make the energy of the second radiation branch greater than that of the first radiation branch in a specific way, so as to weaken the excitation of the cavity mode, at the same time, the main antenna unit excites the parasitic antenna unit, and the energy of the parasitic antenna unit is concentrated on the third radiation branch far from the second radiation branch, the current direction of the cavity mode is the same as that of the third radiation branch of the parasitic antenna unit, and the two are conjugate modes, so as to suppress the cavity mode through the parasitic antenna unit, achieve the purpose of weakening or canceling the cavity mode, and then eliminate the cavity spurious wave. After the spurious wave is eliminated in the above-mentioned manner, the radiation efficiency of the antenna is obviously improved.

[0006] When the energy of the spurious wave is concentrated on the top and bottom of the cavity, the first step to eliminate the spurious wave is to concentrate the energy of the main antenna unit on the first radiation branch far from the bottom, i.e. to make the energy of the first radiation branch greater than that of the second radiation branch in a specific way, so as to weaken the excitation of the cavity mode, at the same time, the main antenna unit excites the parasitic antenna unit, and the energy of the parasitic antenna unit is concentrated on the fourth radiation branch far from the first radiation branch, and the current direction of the cavity mode is the same as that of the fourth radiation branch of the parasitic antenna unit, and the two are conjugate modes, so as to suppress the cavity mode through the parasitic antenna unit, achieve the purpose of weakening or canceling the cavity mode, and then eliminate the cavity spurious wave. After the spurious wave is eliminated, the radiation efficiency of the antenna is obviously improved.

[0007] In a specific embodiment, the main antenna unit further comprises a first adjusting device for adjusting the field strength distribution ratio of the first radiation branch and the second radiation branch, so that the first radiation branch or the second radiation branch is the main radiator of the main antenna unit, thereby realizing the free switching of the main radiator of the main antenna unit between the first radiation branch and the second radiation branch to eliminate the spurious wave of the cavity.

[0008] In a specific embodiment, the first radiation branch has a first open circuit end, the second radiation branch has a second open circuit end, and the first open circuit end and the second open circuit end have a first grounding end and a feeding end therebetween; the first adjusting device comprises a first switch and a second switch which are conductive to ground, the first switch is arranged between the first open circuit end and the first grounding end, and the second switch is arranged between the second open circuit end and the first grounding end, one of the first switch and the second switch is conductive and the other is disconnected, so that the main radiator of the main antenna unit can be the first radiation branch or the second radiation branch through the conduction or disconnection of the first switch and the second switch.

[0009] In one embodiment, the parasitic antenna unit further comprises a second adjusting device for adjusting the field intensity distribution ratio of the third radiating branch and the fourth radiating branch, so that the third radiating branch or the fourth radiating branch is the main radiator of the parasitic antenna unit, thereby realizing the free switching of the main radiator of the parasitic antenna unit between the third radiating branch and the fourth radiating branch, and eliminating the spurious of the cavity.

[0010] In one embodiment, the resonant mode of the parasitic antenna unit is a / wavelength resonant mode.

[0011] In one embodiment, the third radiating branch has a third open end, the fourth radiating branch has a fourth open end, and there is at least one second ground end between the third open end and the fourth open end; the second adjusting device comprises a third switch and a fourth switch, the third switch is arranged between the third open end and the second ground end, and the fourth switch is arranged between the fourth open end and the second ground end, one of the third switch and the fourth switch is turned on, and the other is turned off, thereby realizing that the main radiator of the parasitic antenna unit is the third radiating branch or the fourth radiating branch through the turn-on or turn-off of the third switch and the fourth switch.

[0012] In one embodiment, the resonant mode of the parasitic antenna unit is a / wavelength resonant mode to a / wavelength resonant mode.

[0013] In one embodiment, the second adjusting device comprises a first tuning device and a second tuning device, the first tuning device connects the third open end and the ground, and is used for adjusting the capacitance or inductance between the third open end and the ground, and the second tuning device connects the fourth open end and the ground, and is used for adjusting the capacitance or inductance between the fourth open end and the ground.

[0014] The first tuning device is used for adjusting the capacitance between the third radiating branch and the ground, and the second tuning device is used for adjusting the capacitance between the fourth radiating branch and the ground. When the capacitance between the third radiating branch and the ground is large under the adjustment of the first tuning device, and the capacitance between the fourth radiating branch and the ground is small under the adjustment of the second tuning device, the third radiating branch is approximately turned on, at this time, the mode of the parasitic antenna unit is biased to the side of the fourth radiating branch, that is, the field intensity of the fourth radiating branch is greater than that of the third radiating branch. Similarly, when the capacitance between the third radiating branch and the ground is small under the adjustment of the first tuning device, and the capacitance between the fourth radiating branch and the ground is large under the adjustment of the second tuning device, the fourth radiating branch is approximately turned on, at this time, the mode of the parasitic antenna unit is biased to the side of the third radiating branch, that is, the field intensity of the third radiating branch is greater than that of the fourth radiating branch.

[0015] When the energy of the spurious wave generated in the working process of the antenna is concentrated in the side of the cavity, the second switch is turned off and the first switch is turned on, so that the mode of the main antenna unit is switched to the mode of the second radiation branch located in the bottom, thereby making the main antenna unit away from the electric field of the cavity and reducing the excitation of the cavity by the main antenna unit. Meanwhile, when the first tuning device reduces the capacitance between the third radiation branch and the ground and the second tuning device increases the capacitance between the fourth radiation branch and the ground, the fourth radiation branch is approximately turned on, and at this time, the mode of the parasitic antenna unit is biased to the side of the third radiation branch. The third radiation branch and the cavity are in a conjugate mode, so that the mode of the cavity is eliminated through the mode of the third radiation branch, thereby transferring the energy of the spurious wave of the cavity to the third radiation branch and improving the radiation efficiency of the antenna.

[0016] When the energy of the spurious wave generated in the working process of the antenna is concentrated in the bottom of the cavity, the first switch is turned off and the second switch is turned on, so that the mode of the main antenna unit is switched to the mode of the first radiation branch located in the side, thereby making the main antenna unit away from the electric field of the cavity and reducing the excitation of the cavity by the main antenna unit. Meanwhile, when the first tuning device increases the capacitance between the third radiation branch and the ground and the second tuning device reduces the capacitance between the fourth radiation branch and the ground, the third radiation branch is approximately turned on, and at this time, the mode of the parasitic antenna unit is biased to the side of the fourth radiation branch. The fourth radiation branch and the cavity are in a conjugate mode, so that the mode of the cavity is eliminated through the mode of the fourth radiation branch, thereby transferring the energy of the spurious wave of the cavity to the fourth radiation branch and improving the radiation efficiency of the antenna.

[0017] In other embodiments, the first tuning device can also be used to adjust the inductance between the third radiation branch and the ground, and the second tuning device is used to adjust the inductance between the fourth radiation branch and the ground. When the inductance between the third radiation branch and the ground is small under the adjustment of the first tuning device and the inductance between the fourth radiation branch and the ground is large under the adjustment of the second tuning device, the third radiation branch is approximately turned on, and at this time, the mode of the parasitic antenna unit is biased to the side of the fourth radiation branch, that is, the field strength of the fourth radiation branch is greater than that of the third radiation branch. Similarly, when the inductance between the third radiation branch and the ground is large under the adjustment of the first tuning device and the inductance between the fourth radiation branch and the ground is small under the adjustment of the second tuning device, the fourth radiation branch is approximately turned on, and at this time, the mode of the parasitic antenna unit is biased to the side of the third radiation branch, that is, the field strength of the third radiation branch is greater than that of the fourth radiation branch.

[0018] Therefore, in the embodiment, the distribution of the electric field between the third radiation branch and the fourth radiation branch is adjusted by the first tuning device and the second tuning device, so that the mode of the parasitic antenna unit is adjusted. In the electronic device, the first tuning device and the second tuning device are controlled by the internal control device, so that the mode switching of the parasitic antenna unit is realized.

[0019] In a specific embodiment, the second adjusting device includes a first tuning device, the first tuning device is connected between the third open end and the ground, and is used to adjust the capacitance or inductance between the third open end and the ground; the fourth radiation branch is suspended, so that the distribution of the electric field between the third radiation branch and the fourth radiation branch is adjusted, and the mode of the parasitic antenna unit is adjusted.

[0020] In a specific embodiment, the second adjusting device includes a second tuning device, the second tuning device is connected between the fourth open end and the ground, and is used to adjust the capacitance or inductance between the fourth open end and the ground; the third radiation branch is suspended, so that the distribution of the electric field between the third radiation branch and the fourth radiation branch is adjusted, and the mode of the parasitic antenna unit is adjusted.

[0021] In a specific embodiment, the folding electronic device includes a control device, the main antenna unit includes a first adjusting device, the parasitic antenna unit includes a second adjusting device, and the control device is used to control the first adjusting device and the second adjusting device, so that the first radiation branch is the main radiator of the main antenna unit, the fourth radiation branch is the main radiator of the parasitic antenna unit, or the second radiation branch is the main radiator of the main antenna unit, and the third radiation branch is the main radiator of the parasitic antenna unit. Therefore, the control device can determine the position where the energy of the spurious wave generated by the antenna is concentrated according to the frequency band in which the antenna works, so as to determine the working mode of the main antenna unit and the parasitic antenna unit according to the spurious wave, and control the first adjusting device and the second adjusting device according to the determination result, so that the main antenna unit and the parasitic antenna unit are in a specific mode, so as to eliminate the cavity spurious wave generated in the working process of the antenna.

[0022] In one embodiment, the first radiating branch has a first open end, the second radiating branch has a second open end, the first open end and the second open end have a first ground end and a feeding end therebetween, the third radiating branch has a third open end, the fourth radiating branch has a fourth open end, the third open end and the fourth open end have at least one second ground end therebetween; the first adjusting device comprises a first switch and a second switch which are connected to ground, the first switch is arranged between the first open end and the first ground end, the second switch is arranged between the second open end and the first ground end; the second adjusting device comprises a third switch and a fourth switch, the third switch is arranged between the third open end and the second ground end, the fourth switch is arranged between the fourth open end and the second ground end; the control device is configured to control the first switch to be turned on, the second switch to be turned off, the third switch to be turned off, and the fourth switch to be turned on, or the control device is configured to control the first switch to be turned off, the second switch to be turned on, the third switch to be turned on, and the fourth switch to be turned off.

[0023] In one embodiment, the first radiating branch has a first open end, the second radiating branch has a second open end, the first open end and the second open end have a first ground end and a feeding end therebetween, the third radiating branch has a third open end, the fourth radiating branch has a fourth open end, the third open end and the fourth open end have at least one second ground end therebetween; the first adjusting device comprises a first switch and a second switch which are connected to ground, the first switch is arranged between the first open end and the first ground end, the second switch is arranged between the second open end and the first ground end; the second adjusting device comprises a first tuning device and / or a second tuning device, the first tuning device connects the third open end to ground, the first tuning device is configured to adjust a capacitance or an inductance between the third open end and ground, and / or the second tuning device connects the fourth open end to ground, the second tuning device is configured to adjust a capacitance or an inductance between the fourth open end and ground; the control device is configured to control the first switch to be turned on, the second switch to be turned off, and control the first tuning device and / or the second tuning device to make a capacitance between the third radiating branch and ground smaller than a capacitance between the fourth radiating branch and ground, or the control device is configured to control the first switch to be turned off, the second switch to be turned on, and control the first tuning device and / or the second tuning device to make a capacitance between the third radiating branch and ground larger than a capacitance between the fourth radiating branch and ground.

[0024] In one embodiment, the first main body has a first metal frame, and the first radiating branch and the second radiating branch are arranged in the first metal frame; the second main body has a second metal frame, and the third radiating branch and the fourth radiating branch are arranged in the second metal frame.

[0025] It should be understood that the general description above and the following detailed description are only exemplary and are not limiting to the present application. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 A partial structure schematic diagram of an electronic device provided in the present application, in which the electronic device is in a folded state;

[0027] Figure 2 A top view of the electronic device shown in Figure 1 A top view of the antenna shown in one embodiment;

[0028] Figure 3 A top view of the antenna shown in Figure 2 A return loss curve diagram of the antenna shown in an ideal state;

[0029] Figure 4 A return loss simulation curve diagram of the antenna shown in actual use; Figure 2

[0030] A schematic diagram of an ideal cavity; Figure 5

[0031] A schematic diagram of an equivalent cavity of the electronic device shown in Figure 6 Figure 1 A schematic diagram of the electric field distribution of the equivalent cavity shown in

[0032] Figures 7-9 Figure 6 A schematic diagram of the electric field distribution obtained by cavity mode analysis on the electronic device shown in

[0033] Figures 10-11 A schematic diagram of the electric field distribution obtained by cavity mode analysis on the electronic device shown in Figure 1

[0034] A schematic diagram of the principle of the main antenna unit resonance; Figure 12

[0035] A top view of the antenna provided in the present application in one embodiment; Figure 13

[0036] A schematic diagram of the return loss simulation results of the antenna when eliminating the cavity clutter shown in Figure 14 Figure 10 A schematic diagram of the return loss simulation results of the antenna when eliminating the cavity clutter shown in

[0037] Figure 15 A schematic diagram of the return loss simulation results of the antenna when eliminating the cavity clutter shown in Figure 10 ​​The simulation result of the radiation efficiency of the antenna when the cavity is loaded with a wave;

[0038] Figure 16 To eliminate Figure 11 The simulation result of the return loss of the antenna when the cavity is loaded with a wave;

[0039] Figure 17 To eliminate Figure 11 The simulation result of the radiation efficiency of the antenna when the cavity is loaded with a wave;

[0040] Figure 18 The topology of the antenna provided by the present application in a specific embodiment;

[0041] Figure 19 The topology of the antenna provided by the present application in another specific embodiment;

[0042] Figure 20 The topology of the antenna provided by the present application in still another specific embodiment;

[0043] Figure 21 The topology of the antenna provided by the present application in still another specific embodiment;

[0044] Figure 22 The topology of the antenna provided by the present application in still another specific embodiment.

[0045] Reference signs:

[0046] 1 - first body;

[0047] 2 - second body;

[0048] 3 - rotation axis;

[0049] 4 - main antenna unit;

[0050] 41 - first radiating branch;

[0051] 411 - first open end;

[0052] 42 - second radiating branch;

[0053] 421 - second open end;

[0054] 43 - first ground end;

[0055] 44 - first switch;

[0056] 45 - feeding end;

[0057] 46 - second switch;

[0058] 5 - parasitic antenna unit;

[0059] 51 - third radiating branch;

[0060] 52 - fourth radiating branch;

[0061] 53 - second location;

[0062] 54 - third switch;

[0063] 55 - fourth switch;

[0064] 56 - third ground terminal;

[0065] 57 - first tuning device;

[0066] 58 - second tuning device;

[0067] 6 - cavity;

[0068] 7 - screen.

[0069] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate embodiments consistent with the present application and, together with the description, further serve to explain the principles of the application. DETAILED DESCRIPTION

[0070] In order to better understand the technical solutions of the present application, the embodiments of the present application will be described in detail below in conjunction with the drawings.

[0071] In a specific embodiment, the present application is further described in detail below through specific embodiments and in conjunction with the drawings.

[0072] The technical solutions provided by the present application are applicable to electronic devices using one or more of the following communication technologies: global mobile communication (GSM) technology, code division multiple access (CDMA) communication technology, wideband code division multiple access (WCDMA) communication technology, general packet radio service (GPRS), long term evolution (LTE) communication technology, Wi-Fi communication technology, 5G communication technology, millimeter wave (mmWave) communication technology, SUB-6G communication technology, and other future communication technologies. The following embodiments do not highlight the requirements of the communication network, and only illustrate the working characteristics of the antenna in terms of frequency band height.

[0073] In addition, in this application, the electronic device can be a mobile phone, a tablet computer, a personal digital assistant (PDA), and the like. The specific form of the electronic device is not specially limited in the embodiments of this application, and the following is described by taking a mobile phone as an example for convenience.

[0074] As shown in Figure 1 The electronic device includes a rotating shaft 3, a screen 7, a first body 1, and a second body 2. The screen 7 can be a flexible screen for displaying images, videos, and the like. The specific type of the flexible screen is not limited in this application. For example, the flexible screen can be an active-matrix organic light-emitting diode (AMOLED) display screen. The AMOLED display screen is a self-luminous display screen, and does not need to be provided with a back light module (BLM). Therefore, when the substrate of the AMOLED display screen is made of a flexible resin material, such as polyethylene terephthalate (PET), the AMOLED display screen can have a bendable characteristic. For example, the flexible screen can also be an organic light-emitting diode (OLED) display screen, a mini organic light-emitting diode display screen, a micro organic light-emitting diode display screen, a micro organic light-emitting diode display screen, a quantum dot light emitting diode (QLED) display screen, and the like.

[0075] The screen 7 is connected to (for example, pasted to) the first body 1 and the second body 2, so that the screen 7 can be kept as flat as possible during use, and the non-display surface of the screen 7 is protected. The rotating shaft 3 is located between the first body 1 and the second body 2, and is connected to the first body 1 and the second body 2. At the same time, the first body 1, the second body 2, and the screen 7 are connected to form a containing cavity for containing the internal structure of the electronic device, such as a circuit board assembly, a battery, a processor, a radio frequency module, and the like.

[0076] During use of the electronic device, the rotating shaft 3 at least includes an unfolded state and a folded state. In the unfolded state, the first body 1 and the second body 2 are located in substantially the same plane, so that the screen 3 is substantially planar. At this time, the screen 3 is exposed, a user can operate the screen 3, and the screen 3 can display information such as images or videos to achieve large-screen display and improve the user's viewing experience. When the rotating shaft 3 is in the unfolded state, the first body 1 and the second body 2 can be rotated towards each other (i.e., relative rotation of the first body 1 and the second body 2 towards each other), thereby causing the rotating shaft 3 to fold. During folding, the ends of the first body 1 and the second body 2 away from the rotating shaft 3 move towards each other, so that the electronic device is in a folded state, and in this embodiment, the electronic device is of an in-screen folding structure. In the folded state, as shown in FIG. 1B, the flexible screen is located in the space enclosed by the folding of the first body 1 and the second body 2. At this time, the screen 3 is not exposed, and a user cannot operate the screen 3, so that the electronic device is convenient to store and carry. When the rotating shaft 3 is in the folded state, the first body 1 and the second body 2 can be rotated (in a direction opposite to the direction of rotation during folding), thereby causing the rotating shaft 3 to unfold, so that the electronic device is in the unfolded state. Figure 1

[0077] Those skilled in the art can understand that the structure shown in the embodiments of the present application does not constitute a specific limitation on the electronic device. In other possible embodiments of the present application, the electronic device can include more components than shown, or combine certain components, or split certain components, or different component arrangements.

[0078] In specific embodiments, the electronic device in the embodiments of the present application also has a wireless communication function, i.e., the electronic device also includes an antenna for transmitting or receiving electromagnetic wave signals. As shown in the embodiment of FIG. 1C, the antenna includes a main antenna unit 4, which can be provided on the first body 1 of the electronic device. The main antenna unit 4 includes a main radiation branch, a ground port, and a feed port 45. The main radiation branch can be formed by opening a slot in the metal frame of the first body 1. The main radiation branch has two open-circuit ends at the slot, through which signals are radiated outward. The feed port 45 is electrically connected to a feed source for feeding power to the main radiation branch through the feed port 45. The ground port is electrically connected to the first body 1 to achieve grounding of the main radiation branch. The ground port is provided between the two open-circuit ends of the main radiation branch, and the main antenna unit 4 can work in a target frequency band. Figure 2 Figure 2 As shown in the embodiment of FIG. 1D, the antenna of the electronic device can also include a parasitic antenna unit 5, which can be provided on the second body 2 of the electronic device. The parasitic antenna unit 5 includes a parasitic radiation branch and a ground port 53.

[0079] As shown in the embodiment of FIG. 1E, the parasitic antenna unit 5 can be provided on the second body 2 of the electronic device. The parasitic antenna unit 5 includes a parasitic radiation branch and a ground port 53. The parasitic radiation branch can be formed by opening a slot in the metal frame of the second body 2. The parasitic radiation branch has two open-circuit ends at the slot, through which signals are radiated outward. The ground port 53 is electrically connected to the second body 2 to achieve grounding of the parasitic radiation branch. The ground port 53 is provided between the two open-circuit ends of the parasitic radiation branch, and the parasitic antenna unit 5 can work in a target frequency band. Figure 1 Figure 2 ​​​As shown, when the electronic device is in the folded state, the first body 1 and the second body 2 are close to each other and oppositely arranged along the thickness direction Z of the electronic device, so that the main radiation branch of the main antenna unit 4 is oppositely arranged with the parasitic radiation branch of the parasitic antenna unit 5. When the main antenna unit 4 is fed, the electric field coupling is generated between the main radiation branch and the parasitic radiation branch through the gap therebetween, and resonance is generated.

[0080] Figure 2 The three basic modes of the antenna shown are as follows Figure 3 As shown, wherein, Figure 3 In the figure, the a curve represents the mode of the parasitic antenna unit 5, the b curve represents the quarter mode of the bottom of the main antenna unit 4, and the c curve represents the half-wave mode of the feed branch of the main antenna unit 4. The a curve is in front of the b curve and the c curve, so as to improve the radiation efficiency of the antenna when the electronic device is in the folded state. During the operation of the electronic device, when the antenna is free from spurs, theoretically, there are Figure 3 three waves in the figure.

[0081] However, in fact, when the electronic device is in the folded state, the radiation efficiency curve of the antenna is as shown in Figure 4 As shown, Figure 4 In the figure, the a section, the b section, and the c section of the curve are respectively Figure 3 three waveforms shown. As can be seen from Figure 4 , the actual working mode of the antenna includes two modes of mode ① and mode ② in addition to the three basic modes described above. Mode ① and mode ② are generated in different frequency bands of the antenna, and mode ① and mode ② are spurs of the antenna. Due to the existence of the two spurs, the performance of the antenna is reduced. Therefore, the purpose of the present application is to eliminate the two spurs of ① and ② to improve the performance of the antenna. The process of generating the two spurs is described below.

[0082] As shown in Figure 1 , when the electronic device is in the folded state, the first body 1 and the second body 2 form a cavity 6 therebetween, as shown in Figure 5 , which is an ideal closed cavity model. The six surfaces of the closed cavity are ideal short-circuit surfaces (PEC interfaces). The closed cavity is a regular cavity, and the resonances in each direction affect each other and cannot exist independently. In actual projects, unless specifically constructed, such a model generally does not exist.

[0083] It is assumed that the folding direction is the X direction, the constant direction perpendicular to the folding direction is the Y direction, and the double folding direction is the Z direction.

[0084] When the electronic device is in the folded state, the structure of the equivalent cavity thereof is as shown in Figure 6As shown, in this equivalent cavity, the electronic device is not closed at its top and bottom ends along the Y direction, but is closed at its front and rear ends along the Z direction. Along the X direction, one side of the rotating shaft is closed, while the side opposite the rotating shaft is not closed. Therefore, the two surfaces of this equivalent cavity along the Z direction are short-circuit surfaces (PEC interfaces), the surface on the rotating shaft side along the X direction is a short-circuit surface (PEC interface), and the surface opposite the rotating shaft is an open-circuit surface (PMC interface). The two surfaces along the Y direction are also open-circuit surfaces (PMC interfaces). That is, this equivalent cavity is a basic model of 3PMC+3PEC.

[0085] In the X-direction fx, the equivalent cavity, due to a short circuit on one side (PEC) and an open circuit on the other side (PMC), can be considered as a quarter-fundamental mode with a magnetic wall in the middle. That is, the most fundamental mode of the actual fx is represented by the folded inner screen, with a length along the X-direction equal to half the wavelength of the fundamental mode. The mode corresponding to its physical length is the f(0.5,y,z) mode, and the electric field distribution corresponding to its fundamental mode is as follows: Figure 7 As shown, from Figure 7 It can be seen that the point of maximum electric field in this mode is on the side of the cavity. In fy in the Y direction, both ends of the equivalent cavity are open surfaces (PMC), its fundamental mode is the half-mode corresponding to the Y direction, and the mode corresponding to its physical length is the f(x,1,z) mode. The electric field distribution corresponding to the fundamental mode is as follows. Figure 8 As shown, from Figure 8 It can be seen that the largest electric field points of the cavity in this mode are at the top and bottom ends of the cavity. Similarly, the mode of the Z-axis equivalent cavity is f(0.5,2,0), and the electric field distribution corresponding to this basic mode is as follows: Figure 9 As shown.

[0086] like Figure 4 As shown, when the electronic device is in a folded state, the antenna exhibits two clutter signals, ① and ②. The result of mode analysis for clutter ① is as follows. Figure 10 As shown, the results of the mode analysis for clutter ② are as follows: Figure 11 As shown. From Figure 2 It can be seen that, under clutter mode ①, the strongest electric field is located on the side of the electronic device, and... Figure 7 The basic pattern of the cavity shown matches; from Figure 3 It can be seen that, in clutter mode ②, the strong electric field points are at the top and bottom of the electronic device, and... Figure 8 The basic pattern of the cavity shown matches.

[0087] Therefore, it can be seen that when the electronic device is in a folded state, the generation of the two clutter waves of the antenna is due to the excitation of the cavity fundamental mode f(0.5,y,z) and the cavity fundamental mode f(x,1,z) by the main antenna element 4. After the cavity mode is excited, the energy of the antenna is concentrated in the cavity and cannot be radiated outward, which affects the efficiency and in-band performance of the antenna.

[0088] Based on this, in the embodiments of the present application, the two spurs ① and ② in the antenna are eliminated by preventing the basic mode of the cavity from being excited. The specific principle is shown in Figure 12 Figure 12 In the figure, the solid arrow represents the direction of the current in the main radiation branch of the main antenna unit 4, which produces electric field coupling with the parasitic radiation branch, thereby exciting current on the parasitic radiation branch, and the current on the parasitic radiation branch is opposite to the direction of the current on the main radiation branch, so Figure 12 In the figure, the dotted arrow represents the direction of the current in the parasitic radiation branch. At the same time, the main antenna unit 4 also excites the basic mode of the cavity during operation, thereby exciting current in the cavity 6, and the direction of the current in the cavity 6 is opposite to the direction of the current in the main radiation branch, as shown by the dashed arrow in Figure 12 Figure 12 It can be known that the current directions of the parasitic antenna mode and the cavity mode excited by the main antenna unit 4 are the same, and the two are conjugate modes, which suppress each other, so the cavity mode can be suppressed by the parasitic antenna mode. This idea is the basic idea of the present application, and the following embodiments describe the specific ways to realize this idea.

[0089] As Figure 13 ​​The main radiation branch of the main antenna unit includes a first radiation branch 41 and a second radiation branch 42. The first radiation branch 41 can be arranged on the side of the first main body, and the second radiation branch 42 can be arranged on the bottom of the first main body. Thus, the main radiation branch can be an L-shaped branch. Similarly, the parasitic radiation branch of the parasitic antenna unit includes a third radiation branch 51 and a fourth radiation branch 52. The third radiation branch 51 can be arranged on the side of the second main body, and the fourth radiation branch 52 can be arranged on the bottom of the second main body. Thus, the parasitic radiation branch can also be an L-shaped branch. Meanwhile, the main radiation branch can be formed by slitting the metal frame of the first main body. That is, the first radiation branch 41 of the main radiation branch has a first open end 411, and the second radiation branch 42 has a second open end 421. The main antenna unit radiates energy outward through the first open end 411 and the second open end 421. That is, the position of the maximum electric field of the first radiation branch 41 is at or close to the first open end 411, and the position of the maximum electric field of the second radiation branch 42 is at or close to the second open end 421. The parasitic radiation branch can be formed by slitting the metal frame of the second main body. That is, the third radiation branch 51 of the parasitic radiation branch has a third open end 511, and the fourth radiation branch 52 has a fourth open end 521. The parasitic antenna unit radiates energy outward through the third open end 511 and the fourth open end 521. That is, the position of the maximum electric field of the third radiation branch 51 is at or close to the third open end 511, and the position of the maximum electric field of the fourth radiation branch 52 is at or close to the fourth open end 521.

[0090] Thus, when the electric field intensity of the first open end 411 is greater than that of the second open end 421, the main antenna unit mainly radiates energy outward through the first radiation branch 41. That is, the main antenna unit is mainly in the mode of the first radiation branch 41. When the electric field intensity of the second open end 421 is greater than that of the first open end 411, the main antenna unit is mainly in the mode of the second radiation branch 42. Similarly, when the electric field intensity of the third open end 511 is greater than that of the fourth open end 521, the parasitic antenna unit mainly radiates energy outward through the third radiation branch 51. That is, the parasitic antenna unit is mainly in the mode of the third radiation branch 51. When the electric field intensity of the fourth open end 521 is greater than that of the third open end 511, the parasitic antenna unit is mainly in the mode of the fourth radiation branch 52.

[0091] As can be understood by those skilled in the art, when the electric field of the main antenna unit is close to the cavity, the excitation of the cavity is strong, and the energy of the cavity is large. When the electric field of the main antenna unit is far away from the cavity, the excitation of the cavity is weak, and the energy of the cavity is small. Thus, when the antenna excites the cavity mode Figure 10In the f(0.5,y,z) mode shown, the energy of the cavity is mainly concentrated on the side of the cavity. At this time, if the energy of the main radiating stub in the main antenna element is also concentrated on the side (first radiating stub 41), the distance to the cavity is relatively close, and the excitation of the cavity is strong. If the energy of the main radiating stub in the main antenna element is concentrated at the bottom (second radiating stub 42), the distance to the cavity is relatively far, and the excitation of the cavity is weak.

[0092] Therefore, in the approach to eliminating the two clutters mentioned above, the first step is to move the electric field of the main antenna element away from the cavity, thereby weakening the excitation on the cavity. The second step can be based on... Figure 12 The principle is to suppress cavity modes by using the modes of parasitic antenna elements conjugate with the cavity to eliminate clutter.

[0093] Specifically, when eliminating Figure 10 When the cavity clutter (clutter ①) is shown, since the energy of the clutter is concentrated on the side of the cavity, the first step in eliminating the clutter is to concentrate the energy of the main antenna element on the second radiating stub 42, which is far from the side. That is, the energy of the second radiating stub 42 is made greater than the energy of the first radiating stub 41 in a specific way, thereby reducing the excitation of the cavity mode. At the same time, the main antenna element excites the parasitic antenna element, and the energy of the parasitic antenna element is concentrated on the third radiating stub 51, which is far from the second radiating stub 42. The current direction of the cavity mode is the same as the current direction of the third radiating stub 51 in the parasitic antenna element. The two are conjugate modes. Thus, the cavity mode is suppressed by the parasitic antenna element, thereby achieving the purpose of weakening or canceling the cavity mode and eliminating the cavity clutter.

[0094] After eliminating clutter using the methods described above, the simulation results are as follows: Figure 14 and Figure 15 As shown. Figure 14 This represents the return loss curve. Figure 15 This represents the radiation efficiency curve. For example... Figure 14 As shown, S1 represents the return loss before clutter removal, S2 represents the return loss during clutter removal, and S3 represents the return loss after clutter removal. Figure 15 As shown, E1 represents the radiation efficiency before clutter removal, E2 represents the radiation efficiency during clutter removal, and E3 represents the radiation efficiency after clutter removal.

[0095] like Figure 14As shown, the cavity resonates at 0.64 GHz, and the parasitic antenna element resonates at 0.713 GHz. At this point, due to the distance between the cavity mode and the parasitic antenna element mode, clutter is not completely eliminated, and the antenna's radiation efficiency is improved. To further eliminate this clutter, the parasitic antenna element mode can be moved closer to the cavity mode, thereby squeezing the cavity. During this process, because the cavity mode is weakened (the main antenna element moves away from the cavity mode), the parasitic antenna element mode becomes stronger than the cavity mode, thus causing the cavity mode to be canceled out by the parasitic antenna mode. Figure 15 The E2 and E3 curves gradually overlap, indicating that energy is transferred from the cavity mode to the parasitic radiating branches of the parasitic antenna element. From Figure 15 It can be seen that without clutter elimination, the antenna's radiation efficiency is less than 20%, and after clutter elimination, the antenna's radiation efficiency is significantly improved after 0.713 GHz.

[0096] Similarly, when eliminating Figure 11 When the cavity clutter (clutter ②) is shown, since the energy of the clutter is concentrated at the top and bottom of the cavity, the first step in eliminating the clutter is to concentrate the energy of the main antenna element on the first radiating branch 41 away from the bottom. That is, the energy of the first radiating branch 41 is made greater than the energy of the second radiating branch 42 in a specific way, thereby reducing the excitation of the cavity mode. At the same time, the main antenna element excites the parasitic antenna element, and the energy of the parasitic antenna element is concentrated on the fourth radiating branch 52 away from the first radiating branch 41. The current direction of the cavity mode is the same as the current direction of the fourth radiating branch 52 in the parasitic antenna element. The two are conjugate modes. Thus, the cavity mode is suppressed by the parasitic antenna element, thereby achieving the purpose of weakening or canceling the cavity mode and eliminating the cavity clutter.

[0097] After eliminating clutter using the methods described above, the simulation results are as follows: Figure 16 and Figure 17 As shown, Figure 16 This represents the return loss curve. Figure 17 This represents the radiation efficiency curve. For example... Figure 16 As shown, S4 represents the return loss before clutter removal, S5 represents the return loss during clutter removal, and S6 represents the return loss after clutter removal. Figure 17 As shown, E4 represents the radiation efficiency before clutter removal, E5 represents the radiation efficiency during clutter removal, and E6 represents the radiation efficiency after clutter removal.

[0098] like Figure 16As shown, the spurious wave caused by the resonance of the cavity is at the position of 0.94GHz, and the resonance of the parasitic antenna unit is at the position of 0.62GHz. At this time, since the mode of the cavity and the mode of the parasitic antenna unit have a distance, the spurious wave is not completely eliminated, and the radiation efficiency of the antenna is improved. If the spurious wave is to be further eliminated, the mode of the parasitic antenna unit can be continuously moved towards the direction of the mode of the cavity, so as to squeeze the cavity. In this process, since the mode of the cavity is weakened (the main antenna unit is far away from the mode of the cavity), the mode of the parasitic antenna unit is stronger than the mode of the cavity, so that the mode of the cavity is cancelled by the mode of the parasitic antenna, Figure 17 As shown in the E5 and E6 curves in FIG. 8, the energy is gradually transferred from the mode of the cavity to the parasitic radiation branch of the parasitic antenna unit. As shown in the E5 and E6 curves in FIG. 8, the energy is gradually transferred from the mode of the cavity to the parasitic radiation branch of the parasitic antenna unit. From Figure 15 It can be known that after the spurious wave is eliminated, the radiation efficiency of the antenna is obviously improved after 0.94GHz.

[0099] It should be noted that when the energy of the main antenna unit is concentrated in the first radiation branch 41, that is, the first radiation branch 41 is the main radiator of the main antenna unit, it does not mean that the second radiation branch 42 does not radiate. When the energy of the main antenna unit is concentrated in the second radiation branch 42, that is, the second radiation branch 42 is the main radiator of the main antenna unit, it also does not mean that the first radiation branch 41 does not radiate. When the energy of the parasitic antenna unit is concentrated in the third radiation branch 51, that is, the third radiation branch 51 is the main radiator of the parasitic antenna unit, it does not mean that the fourth radiation branch 52 does not radiate. When the energy of the parasitic antenna unit is concentrated in the fourth radiation branch 52, that is, the fourth radiation branch 52 is the main radiator of the parasitic antenna unit, it also does not mean that the third radiation branch 51 does not radiate.

[0100] As can be known from the above-mentioned idea of eliminating the spurious wave, the key to eliminating the spurious wave lies in staggering the mode of the main antenna unit and the mode of the parasitic antenna unit, that is, when the energy of the main antenna unit is concentrated in the first radiation branch 41, the energy of the parasitic antenna unit is concentrated in the fourth radiation branch 52. When the energy of the main antenna unit is concentrated in the second radiation branch 42, the energy of the parasitic antenna unit is concentrated in the third radiation branch 51. Therefore, as long as the main antenna unit and the parasitic antenna unit are staggered, the cavity spurious wave under the corresponding mode can be eliminated.

[0101] At the same time, since the spurious wave ① and the spurious wave ② are in different frequency bands, as long as the corresponding spurious wave is eliminated according to the type of the spurious wave generated by the working frequency band of the antenna, the corresponding spurious wave can be eliminated. For example, Figure 10 As shown in FIG. 9, the antenna works in the first frequency band (for example, 700MHz). At this time, the energy of the cavity spurious wave is concentrated on the side, the energy of the main antenna unit is concentrated in the second radiation branch 42, and the energy of the parasitic antenna unit is concentrated in the third radiation branch 51. As shown in FIG. 9, the antenna works in the first frequency band (for example, 700MHz). At this time, the energy of the cavity spurious wave is concentrated on the side, the energy of the main antenna unit is concentrated in the second radiation branch 42, and the energy of the parasitic antenna unit is concentrated in the third radiation branch 51. Figure 11As shown, the antenna works in the second frequency band (for example, 900MHz), at this time, the energy of the generated cavity spurious is concentrated in the top and bottom, the energy of the main antenna unit is concentrated in the first radiation branch 41, and the energy of the parasitic antenna unit is concentrated in the fourth radiation branch 52. Therefore, in actual use, as long as the mode of the main antenna unit and the parasitic antenna unit is switched according to the frequency band in which the antenna works, so that the electric field energy of the main antenna unit and the electric field energy of the parasitic antenna unit are staggered with each other, the generated cavity spurious can be eliminated.

[0102] In summary, in order to eliminate the cavity spurious generated when the electronic device is in the folded state and improve the performance of the antenna, the main antenna unit of the antenna needs to be able to switch between the modes of the first radiation branch 41 and the second radiation branch 42, and the parasitic antenna unit needs to be able to switch between the modes of the third radiation branch 51 and the fourth radiation branch 52, and the switching of the modes of the two is key to adjusting the electric field distribution of each radiation branch. Taking the main antenna unit as an example, the embodiments of the present application can adjust the electric field distribution ratio of the first radiation branch 41 and the second radiation branch 42, for example, the electric field distribution ratio of the first radiation branch 41 and the second radiation branch 42 is 2:8, then the mode of the second radiation branch 42 is the main mode of the main antenna unit; for example, the electric field distribution ratio of the first radiation branch 41 and the second radiation branch 42 is 7:3, then the mode of the first radiation branch 41 is the main mode of the main antenna unit. The electric field distribution of the parasitic antenna unit is similar. The specific switching mode of the antenna mode is described below.

[0103] In a specific embodiment, the main antenna unit further comprises a first adjusting device for adjusting the field intensity distribution ratio of the first radiation branch 41 and the second radiation branch 42, so that the first radiation branch 41 or the second radiation branch 42 is the main radiator of the main antenna unit. The parasitic antenna unit can also comprise a second adjusting device for adjusting the field intensity distribution ratio of the third radiation branch 51 and the fourth radiation branch 52, so that the third radiation branch 51 or the fourth radiation branch 52 is the main radiator of the parasitic antenna unit.

[0104] In a specific embodiment, as Figure 18As shown, the first adjusting device includes the first switch 46 and the second switch 44, and the second adjusting device includes the third switch 44 and the fourth switch 45. The first radiation branch 41 of the main antenna unit is provided with the second switch 46, and the second radiation branch 42 is provided with the first switch 44. The first switch 44 and the second switch 46 are both connected to the ground of the first main body, and the first switch 44 and the second switch 46 are connected to the first ground terminal 43 which is connected to the ground of the first main body. The third radiation branch 51 of the parasitic antenna unit is provided with the third switch 54, and the fourth radiation branch 52 is provided with the fourth switch 55. The third switch 54 and the fourth switch 55 are connected to the second ground terminal 53 which is connected to the ground of the second main body.

[0105] Therefore, for the main antenna unit, when the second switch 46 is connected and the first switch 44 is disconnected, the first radiation branch 41 forms a closed loop with the ground, and the second open end 421 of the second radiation branch 42 radiates energy outward. At this time, the main antenna unit is mainly in the mode of the second radiation branch 42, that is, the main antenna unit switches to the mode of the second radiation branch 42. Similarly, when the first switch 46 is disconnected and the second switch 44 is connected, the main antenna unit switches to the mode of the first radiation branch 41. Therefore, for the main antenna unit, only the connection or disconnection of the first switch 44 and the second switch 46 is needed to switch the mode of the main antenna unit. Similarly, for the parasitic antenna unit, when the third switch 54 is connected and the fourth switch 55 is disconnected, the third radiation branch 51 forms a closed loop with the ground, and the fourth open end 521 of the fourth radiation branch 52 radiates energy outward. At this time, the parasitic antenna unit is mainly in the mode of the fourth radiation branch 52, that is, the parasitic antenna unit switches to the mode of the fourth radiation branch 52. Similarly, when the first switch 46 is disconnected and the second switch 44 is connected, the parasitic antenna unit switches to the mode of the third radiation branch 51. Therefore, for the parasitic antenna unit, only the connection or disconnection of the fourth switch 55 and the third switch 54 is needed to switch the mode of the parasitic antenna unit.

[0106] When the above-mentioned spurious ① occurs during the operation of the antenna, the energy of the spurious is concentrated on the side of the cavity. At this time, the second switch 44 is disconnected, the first switch 46 is connected, the third switch 54 is disconnected, and the fourth switch 55 is connected. Therefore, the mode of the main antenna unit is switched to the mode of the second radiation branch 42 located at the bottom, so that the main antenna unit is away from the electric field of the cavity, and the excitation of the cavity by the main antenna unit is reduced. At the same time, the mode of the parasitic antenna unit is switched to the mode of the third radiation branch 51 located at the side, and the third radiation branch 51 is in a conjugate mode with the cavity. Therefore, the mode of the cavity is eliminated by the mode of the third radiation branch 51, so that the energy of the spurious of the cavity is transferred to the third radiation branch 51, and the radiation efficiency of the antenna is improved.

[0107] When the antenna produces the above-mentioned spurious ② during operation, the energy of the spurious is concentrated at the bottom of the cavity. At this time, the first switch 46 is turned off, the second switch 44 is turned on, the third switch 54 is turned on, and the fourth switch 55 is turned on, so that the mode of the main antenna unit is switched to the mode of the first radiation branch 41 located at the side, so that the main antenna unit is away from the electric field of the cavity, reducing the excitation of the cavity by the main antenna unit, and at the same time, the mode of the parasitic antenna unit is switched to the mode of the fourth radiation branch 52 located at the bottom, and the fourth radiation branch 52 is in a conjugate mode with the cavity, so that the mode of the fourth radiation branch 52 eliminates the mode of the cavity, so that the energy of the spurious of the cavity is transferred to the fourth radiation branch 52, improving the radiation efficiency of the antenna.

[0108] In a specific embodiment, as shown in Figure 19 In the embodiment shown in Figure 19 In the embodiment shown in

[0109] In the above two embodiments, the radiation branch of the main antenna unit is grounded at one end and open at the other end, and the radiation branch of the parasitic antenna unit is grounded at one end and open at the other end. The resonance mode of the main antenna unit and the resonance mode of the parasitic antenna unit can both be a quarter-wave resonance mode.

[0110] In addition, in the electronic device, the on or off of the first switch 46 and the second switch 44 is controlled by an internal control device to realize the mode switching of the main antenna unit, and the on or off of the third switch 54 and the fourth switch 55 is controlled by the internal control device to realize the mode switching of the parasitic antenna unit. The control device can be a chip of the electronic device.

[0111] In other embodiments, the resonance mode of the parasitic antenna unit can also be a resonance mode between a quarter-wave mode and a half-wave mode.

[0112] Specifically, as shown in Figures 20-22As shown, the second adjusting device can further include a first tuning device 57 and / or a second tuning device 58. For the parasitic antenna unit, the third open end 511 and the fourth open end 521 can be not grounded, and one end of the third open end 511 can be provided with the first tuning device 57, and / or one end of the fourth open end 521 can be provided with the second tuning device 58, the first tuning device 57 and / or the second tuning device 58 being grounded to the ground of the second body, the first tuning device 57 being used to adjust the inductance or capacitance between the third open end 511 and the ground, and the second tuning device 58 being used to adjust the inductance or capacitance between the fourth open end 521 and the ground, so as to cause the field intensity to be offset between the third radiation branch 51 and the fourth radiation branch 52, adjust the electric field distribution ratio of the third radiation branch 51 and the fourth radiation branch 52, and realize the mode adjustment of the parasitic antenna unit.

[0113] As shown in the embodiment, Figure 20 the first tuning device 57 is used to adjust the capacitance between the third radiation branch 51 and the ground, and the second tuning device 58 is used to adjust the capacitance between the fourth radiation branch 52 and the ground. When the capacitance between the third radiation branch 51 and the ground is made larger under the adjustment of the first tuning device 57, and the capacitance between the fourth radiation branch 52 and the ground is made smaller under the adjustment of the second tuning device 58, the third radiation branch 51 is approximately grounded, at this time, the mode of the parasitic antenna unit is biased to the side of the fourth radiation branch 52, that is, the field intensity of the fourth radiation branch 52 is larger than that of the third radiation branch 51. Similarly, when the capacitance between the third radiation branch 51 and the ground is made smaller under the adjustment of the first tuning device 57, and the capacitance between the fourth radiation branch 52 and the ground is made larger under the adjustment of the second tuning device 58, the fourth radiation branch 52 is approximately grounded, at this time, the mode of the parasitic antenna unit is biased to the side of the third radiation branch 51, that is, the field intensity of the third radiation branch 51 is larger than that of the fourth radiation branch 52.

[0114] As shown in the embodiment, Figure 20When the antenna produces the above-mentioned spurious ① in the working process, the energy of the spurious is concentrated in the side of the cavity, at this time, the second switch 44 is off and the first switch 46 is on, so that the mode of the main antenna unit is switched to the mode of the second radiation branch 42 located in the bottom, so that the main antenna unit is far away from the electric field of the cavity, and the excitation of the main antenna unit to the cavity is reduced. At the same time, when the first tuning device 57 reduces the capacitance between the third radiation branch 51 and the ground and the second tuning device 58 increases the capacitance between the fourth radiation branch 52 and the ground, the fourth radiation branch 52 is approximately conductive, at this time, the mode of the parasitic antenna unit is biased to the side of the third radiation branch 51, and the third radiation branch 51 is in a conjugate mode with the cavity, so that the mode of the cavity is eliminated through the mode of the third radiation branch 51, so that the energy of the spurious of the cavity is transferred to the third radiation branch 51, and the radiation efficiency of the antenna is improved.

[0115] When the antenna produces the above-mentioned spurious ② in the working process, the energy of the spurious is concentrated in the bottom of the cavity, at this time, the first switch 46 is off and the second switch 44 is on, so that the mode of the main antenna unit is switched to the mode of the first radiation branch 41 located in the side, so that the main antenna unit is far away from the electric field of the cavity, and the excitation of the main antenna unit to the cavity is reduced. At the same time, when the first tuning device 57 increases the capacitance between the third radiation branch 51 and the ground and the second tuning device 58 reduces the capacitance between the fourth radiation branch 52 and the ground, the third radiation branch 51 is approximately conductive to the ground, at this time, the mode of the parasitic antenna unit is biased to the side of the fourth radiation branch 52, and the fourth radiation branch 52 is in a conjugate mode with the cavity, so that the mode of the cavity is eliminated through the mode of the fourth radiation branch 52, so that the energy of the spurious of the cavity is transferred to the fourth radiation branch 52, and the radiation efficiency of the antenna is improved.

[0116] In other embodiments, the first tuning device 57 can also be used to adjust the inductance between the third radiation branch 51 and the ground, and the second tuning device 58 is used to adjust the inductance between the fourth radiation branch 52 and the ground. When the inductance between the third radiation branch 51 and the ground is small under the adjustment of the first tuning device 57 and the inductance between the fourth radiation branch 52 and the ground is large under the adjustment of the second tuning device 58, the third radiation branch 51 is approximately conductive to the ground, at this time, the mode of the parasitic antenna unit is biased to the side of the fourth radiation branch 52, that is, the field strength of the fourth radiation branch 52 is greater than that of the third radiation branch 51. Similarly, when the inductance between the third radiation branch 51 and the ground is large under the adjustment of the first tuning device 57 and the inductance between the fourth radiation branch 52 and the ground is small under the adjustment of the second tuning device 58, the fourth radiation branch 52 is approximately conductive, at this time, the mode of the parasitic antenna unit is biased to the side of the third radiation branch 51, that is, the field strength of the third radiation branch 51 is greater than that of the fourth radiation branch 52.

[0117] Therefore, in the embodiment, the distribution of the electric field between the third radiating branch 51 and the fourth radiating branch 52 can be adjusted by the first tuning device 57 and the second tuning device 58, so as to adjust the mode of the parasitic antenna unit. In the electronic device, the first tuning device 57 and the second tuning device 58 are controlled by the internal control device, so as to realize the mode switching of the parasitic antenna unit.

[0118] As shown in the embodiment, in the parasitic antenna unit, the fourth radiating branch 52 is suspended, and the third radiating branch 51 is connected with the first tuning device 57 at one end close to the third open end 511. The first tuning device 57 is used to adjust the capacitance or inductance between the third open end 511 and the ground, so as to adjust the distribution of the electric field between the third radiating branch 51 and the fourth radiating branch 52, and further adjust the mode of the parasitic antenna unit. Figure 21 As shown in the embodiment, in the parasitic antenna unit, the third radiating branch 51 is suspended, and the fourth radiating branch 52 is connected with the second tuning device 58 at one end close to the fourth open end 521. The second tuning device 58 is used to adjust the inductance or capacitance between the fourth open end 521 and the ground, so as to adjust the distribution of the electric field between the third radiating branch 51 and the fourth radiating branch 52, and further adjust the mode of the parasitic antenna unit. Figure 22 As shown in the embodiment, in the parasitic antenna unit, the third radiating branch 51 is suspended, and the fourth radiating branch 52 is connected with the second tuning device 58 at one end close to the fourth open end 521. The second tuning device 58 is used to adjust the inductance or capacitance between the fourth open end 521 and the ground, so as to adjust the distribution of the electric field between the third radiating branch 51 and the fourth radiating branch 52, and further adjust the mode of the parasitic antenna unit. Figure 20 Similar to the adjustment process of the first tuning device 57 or the second tuning device 58, which will not be described herein.

[0119] Those skilled in the art can understand that the key to solving the cavity clutter in the present application is that the main antenna unit and the parasitic antenna unit can freely switch the mode (switch to the bottom or the side). In addition to the above adjustment mode, other adjustment modes can also be used.

[0120] The above merely provides specific implementation of the embodiments of the present application, but the protection scope of the embodiments of the present application is not limited thereto. Any change or replacement within the technical scope disclosed in the embodiments of the present application shall be covered in the protection scope of the embodiments of the present application. Therefore, the protection scope of the embodiments of the present application shall be subject to the protection scope of the claims.

Claims

1. A foldable electronic device, characterized by comprising: The folding electronic device comprises: a first body and a second body connected by a folding device to enable the first body and the second body to rotate relative to each other; an antenna comprising a main antenna unit and a parasitic antenna unit, the main antenna unit being arranged on the first body, the parasitic antenna unit being arranged on the second body, the main antenna unit comprising a first radiating branch and a second radiating branch, the parasitic antenna unit comprising a third radiating branch and a fourth radiating branch, when the folding electronic device is in a folded state, the first radiating branch and the third radiating branch are arranged opposite to each other and spaced apart, and the first radiating branch and the third radiating branch are located at the side of the folding electronic device, the second radiating branch and the fourth radiating branch are arranged opposite to each other and spaced apart, and the second radiating branch and the fourth radiating branch are located at the bottom of the folding electronic device; wherein when the first radiating branch is the main radiator of the main antenna unit, the fourth radiating branch is the main radiator of the parasitic antenna unit, or when the second radiating branch is the main radiator of the main antenna unit, the third radiating branch is the main radiator of the parasitic antenna unit.

2. The foldable electronic device of claim 1, wherein, The main antenna unit further comprises a first adjusting device for adjusting the field strength distribution ratio of the first radiating branch and the second radiating branch, so that the first radiating branch or the second radiating branch is the main radiator of the main antenna unit.

3. The foldable electronic device of claim 2, wherein, The first radiating branch has a first open circuit end, the second radiating branch has a second open circuit end, and the first open circuit end and the second open circuit end have a first ground end and a feeding end therebetween; The first adjusting device comprises a first switch and a second switch which are conductive to ground, the first switch is arranged between the first open circuit end and the first ground end, the second switch is arranged between the second open circuit end and the first ground end, and one of the first switch and the second switch is conductive and the other is disconnected.

4. The foldable electronic device according to any one of claims 1-3, wherein, The parasitic antenna unit further comprises a second adjusting device for adjusting the field strength distribution ratio of the third radiating branch and the fourth radiating branch, so that the third radiating branch or the fourth radiating branch is the main radiator of the parasitic antenna unit.

5. The foldable electronic device of claim 4, wherein, The resonant mode of the parasitic antenna unit is a 1 / 4 wavelength resonant mode.

6. The foldable electronic device of claim 4, wherein, The third radiating branch has a third open circuit end, the fourth radiating branch has a fourth open circuit end, and the third open circuit end and the fourth open circuit end have at least one second ground end therebetween; The second adjusting device comprises a third switch and a fourth switch, the third switch is arranged between the third open circuit end and the second ground end, the fourth switch is arranged between the fourth open circuit end and the second ground end, and one of the third switch and the fourth switch is conductive and the other is closed.

7. The foldable electronic device of claim 4, wherein, The resonant mode of the parasitic antenna unit is between a 1 / 4 wavelength resonant mode and a 1 / 2 wavelength resonant mode.

8. The foldable electronic device of claim 7, wherein, The third radiating branch has a third open circuit end, the fourth radiating branch has a fourth open circuit end; The second adjusting device comprises a first tuning device and a second tuning device, the first tuning device is connected with the third open end and the ground, and is used for adjusting the capacitance or inductance between the third open end and the ground; the second tuning device is connected with the fourth open end and the ground, and is used for adjusting the capacitance or inductance between the fourth open end and the ground.

9. The foldable electronic device of claim 7, wherein, The third radiation branch has a third open end, the fourth radiation branch has a fourth open end, the second adjusting device comprises a first tuning device, the first tuning device is connected with the third open end and the ground, and is used for adjusting the capacitance or inductance between the third open end and the ground; The fourth radiation branch is suspended.

10. The foldable electronic device of claim 7, wherein, The third radiation branch has a third open end, the fourth radiation branch has a fourth open end, the second adjusting device comprises a second tuning device, the second tuning device is connected with the fourth open end and the ground, and is used for adjusting the capacitance or inductance between the fourth open end and the ground; The third radiation branch is suspended.

11. The foldable electronic device of claim 1, wherein, The folding electronic device comprises a control device, the main antenna unit comprises a first adjusting device, the parasitic antenna unit comprises a second adjusting device, and the control device is used for controlling the first adjusting device and the second adjusting device, so that the first radiation branch is the main radiator of the main antenna unit, the fourth radiation branch is the main radiator of the parasitic antenna unit, or the second radiation branch is the main radiator of the main antenna unit, and the third radiation branch is the main radiator of the parasitic antenna unit.

12. The foldable electronic device of claim 11, wherein, The first radiation branch has a first open end, the second radiation branch has a second open end, and the first open end and the second open end have a first ground end and a feeding end between them; the third radiation branch has a third open end, the fourth radiation branch has a fourth open end, and the third open end and the fourth open end have at least one second ground end between them; The first adjusting device comprises a first switch and a second switch which are connected with the ground, the first switch is arranged between the first open end and the first ground end, and the second switch is arranged between the second open end and the first ground end; The second adjusting device comprises a third switch and a fourth switch, the third switch is arranged between the third open end and the second ground end, and the fourth switch is arranged between the fourth open end and the second ground end; The control device is used for controlling the first switch to be turned on, the second switch to be turned off, the third switch to be turned off, and the fourth switch to be turned on, or the control device is used for controlling the first switch to be turned off, the second switch to be turned on, the third switch to be turned on, and the fourth switch to be turned off.

13. The foldable electronic device of claim 11, wherein, The first radiation branch has a first open end, the second radiation branch has a second open end, and the first open end and the second open end have a first ground end and a feeding end between them; the third radiation branch has a third open end, the fourth radiation branch has a fourth open end, and the third open end and the fourth open end have at least one second ground end between them; The first adjusting device comprises a first switch and a second switch which are turned on with the ground, the first switch is arranged between the first open end and the first ground end, and the second switch is arranged between the second open end and the first ground end; The second adjusting device comprises a first tuning device and / or a second tuning device, the first tuning device is connected between the third open end and the ground, and is used for adjusting the capacitance or inductance between the third open end and the ground, and / or the second tuning device is connected between the fourth open end and the ground, and is used for adjusting the capacitance or inductance between the fourth open end and the ground; The control device is used for controlling the first switch to be turned on, the second switch to be turned off, and the first tuning device and / or the second tuning device, so that the capacitance between the third radiation branch and the ground is less than the capacitance between the fourth radiation branch and the ground, or the control device is used for controlling the first switch to be turned off, the second switch to be turned on, and the first tuning device and / or the second tuning device, so that the capacitance between the third radiation branch and the ground is greater than the capacitance between the fourth radiation branch and the ground.

14. The foldable electronic device of any of claims 1-13, wherein, The first main body has a first metal frame, and the first radiation branch and the second radiation branch are arranged in the first metal frame; The second main body has a second metal frame, and the third radiation branch and the fourth radiation branch are arranged in the second metal frame.

Images