Electronic device

Abstract

The utility model relates to the technical field of antennas, and provides electronic equipment which comprises a circuit board and an antenna structure. The antenna structure comprises a main branch knot and a parasitic branch knot. The circuit board is provided with a feed unit, and the feed unit is used for feeding power to the main branch knot. The main branch and the parasitic branch are arranged in a coplanar manner and are respectively connected with the circuit board to the ground; the parasitic branch comprises a first radiation section and a second radiation section which are connected with each other; the main branch knot and the first radiation section extend in the same direction, a gap is formed between the main branch knot and the first radiation section, and the second radiation section is bent relative to the first radiation section. On the basis of the design of the antenna structure, the normal electric field component of the tissue fluid is reversely increased, the tangential electric field component of the tissue fluid is reduced, and the specific absorption rate of the antenna structure of the electronic equipment during working is reduced.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of antennas, and in particular, to an electronic device. BACKGROUND

[0002] With the wide use of electronic devices, the specific absorption rate (SAR) is an index for evaluating the influence of radio frequency electromagnetic field radiation on the human body. Ensuring the compliance of the specific absorption rate during the operation of the antenna of the electronic device is also an important parameter in the design of the antenna of the electronic device. Therefore, how to design the antenna so that the antenna has a low SAR value during operation becomes a technical problem to be solved. CONTENT OF THE INVENTION

[0003] The present disclosure provides an electronic device to at least solve or improve the reduction of the specific absorption rate of the existing antenna structure of the electronic device during operation.

[0004] The present disclosure provides an electronic device, comprising: a circuit board and an antenna structure; the antenna structure comprises a main branch and a parasitic branch;

[0005] The circuit board is provided with a feeding unit, and the feeding unit is used to feed the main branch; the main branch and the parasitic branch are coplanarly arranged and respectively connected to the ground plate of the circuit board.

[0006] The parasitic branch comprises a first radiation segment and a second radiation segment connected to each other; the main branch and the first radiation segment extend in the same direction, and a gap is formed between the main branch and the first radiation segment; and the second radiation segment is arranged in a bent manner relative to the first radiation segment.

[0007] According to the electronic device provided by the embodiment of the present disclosure, when the feeding unit feeds the main branch, the parasitic branch forms an excitation current under the magnetic field excitation of the main branch.

[0008] The excitation current of the parasitic branch flows from the first radiation segment to the second radiation segment, or from the second radiation segment to the first radiation segment, and the flow direction of the excitation current of at least part of the segments on the second radiation segment is opposite to the flow direction of the excitation current on the first radiation segment.

[0009] According to the electronic device provided by the embodiment of the present disclosure, the main branch has a feeding point and a first grounding point, and the parasitic branch has a second grounding point.

[0010] The first ground point is arranged at the first end of the main branch, the gap is formed between the second end of the main branch and the first end of the first radiation segment, one end of the second radiation segment is connected with the first end of the first radiation segment, and the second ground point is arranged at the second end of the first radiation segment.

[0011] The feeding point is arranged close to the first end of the main branch, the feeding unit feeds at the feeding point, and the first ground point and the second ground point are connected with the circuit board ground respectively.

[0012] According to the electronic device provided by the embodiment of the present disclosure, the second radiation segment comprises a first bending segment and a second bending segment.

[0013] The first end of the first bending segment is connected with the first radiation segment, and the second end of the first bending segment is connected with the first end of the second bending segment.

[0014] The second end of the second bending segment is arranged to extend towards a side away from the main branch.

[0015] According to the electronic device provided by the embodiment of the present disclosure, the length of the extension of the second bending segment is less than the length of the extension of the first radiation segment.

[0016] According to the electronic device provided by the embodiment of the present disclosure, the first bending segment is arranged perpendicularly to the first radiation segment, and the second bending segment is arranged in parallel to the first radiation segment.

[0017] According to the electronic device provided by the embodiment of the present disclosure, the length of the extension between the first end and the second end of the main branch corresponds to 1 / 4 working wavelength of the first target frequency band.

[0018] The length of the extension between the feeding point and the second end of the main branch is equal to 75% to 85% of the length of the extension between the first end and the second end of the main branch.

[0019] According to the electronic device provided by the embodiment of the present disclosure, the length of the extension of the parasitic branch along the extension direction thereof is 80% to 120% of 1 / 4 working wavelength of the second target frequency band.

[0020] According to the electronic device provided by the embodiment of the present disclosure, the width of the gap is 25% to 50% of the length of the first bending segment.

[0021] According to the electronic device provided by the embodiment of the present disclosure, the electronic device further comprises a metal middle frame, the metal middle frame is arranged around the periphery of the circuit board, and the main branch and the parasitic branch are formed on one side of the metal middle frame.

[0022] The electronic device provided by the embodiments of the present disclosure is configured with a circuit board and an antenna structure. A feeding unit on the circuit board can feed the main branch of the antenna structure. A gap is formed between the main branch and the first radiation segment, which facilitates resonance through coupling effect. The excitation signal on the main branch is loaded to the parasitic branch through the gap. Since the parasitic branch includes the first radiation segment and the second radiation segment connected by bending, and the main branch and the first radiation segment extend in the same direction, according to the wearing scenario of the human body to the electronic device, the extending direction of the main branch and the first radiation segment is usually parallel to the direction of the human body tissue fluid. This design can inversely increase the electric field component normal to the tissue fluid and reduce the electric field component tangent to the tissue fluid at the same efficiency, so as to reduce the specific absorption rate of the antenna structure of the electronic device during operation. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the present disclosure or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present disclosure, and other drawings can also be obtained by those skilled in the art without any creative effort based on these drawings.

[0024] Figure 1 is a schematic diagram of vector transformation of electromagnetic wave propagation from free space to human body tissue fluid in the prior art.

[0025] Figure 2 is a structural schematic diagram of an exemplary electronic device provided by the present disclosure.

[0026] Figure 3 is a structural schematic diagram of another exemplary electronic device provided by the present disclosure.

[0027] Figure 4 is a structural schematic diagram of an antenna structure provided by an embodiment of the present disclosure.

[0028] Figure 5 is a simulation diagram of current distribution on the parasitic branch when the antenna structure works in the resonant frequency band provided by an embodiment of the present disclosure.

[0029] Figure 6 is a SAR simulation schematic diagram of the screen surface of the electronic device when the antenna structure works in the resonant frequency band provided by an embodiment of the present disclosure.

[0030] Figure 7 is a SAR simulation schematic diagram of the back cover surface of the electronic device when the antenna structure works in the resonant frequency band provided by an embodiment of the present disclosure.

[0031] Figure 8This is a SAR simulation diagram of the button surface of an electronic device when the antenna structure is operating in the resonant frequency band, provided by one embodiment of this disclosure. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this disclosure clearer, the technical solutions of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0033] like Figure 1 As shown, based on the vector transformation relationship of electromagnetic waves propagating from free space to the tissue fluid of the human body, E 1x and E 1y These are the two perpendicular components of the electromagnetic wave E1 along the x-axis and y-axis in free space, E 2x and E 2y These are the two perpendicular components of electromagnetic wave E2 in the tissue fluid along the x-axis and y-axis directions, respectively.

[0034] The following three formulas describe the boundary conditions for electromagnetic wave propagation in different media, thereby describing the transformation from electromagnetic wave E1 in free space to electromagnetic wave E2 in tissue fluid:

[0035] ε1E 1x -ε2E 2x =ρ;

[0036] E 1y -E 2y =0;

[0037] μ1H1-μ2H2=0;

[0038] In the above formula, the dielectric constant and permeability of free space are ε1 and μ1, respectively, the dielectric constant and permeability of tissue fluid are ε2 and μ2, respectively, ρ represents the free charge density, and H1 and H2 are the permeabilities of free space and tissue fluid, respectively.

[0039] From the above formula, we can see that E 1x E1 is the normal component of the electromagnetic wave perpendicular to the tissue fluid. 1y Let E1 be the tangential component of the electromagnetic wave parallel to the tissue fluid. During the propagation of the electromagnetic wave from free space to the tissue fluid of the human body, E... 1x Transformed into E 2x E 1y Transformed into E 2yIn order to maintain the characteristic of the magnetic field line continuity on the boundary condition, the component of the electromagnetic wave along the normal direction of the tissue fluid is severely attenuated after entering the tissue fluid from the free space, and the tangential component is not attenuated.

[0040] Therefore, for the antenna design on the electronic device, the specific absorption rate of the antenna structure of the existing electronic device in operation can be improved by reducing the tangential component of the antenna radiation signal as much as possible.

[0041] The electronic device provided by the embodiments of the present disclosure will be described in detail below in combination with specific embodiments and application scenarios. Figures 2-8 The electronic device provided by the embodiments of the present disclosure will be described in detail below in combination with specific embodiments and application scenarios.

[0042] As shown in Figure 2 , Figure 3 and Figure 4 , Figure 2 is a structural schematic diagram of an exemplary electronic device provided by the present disclosure, Figure 3 is a structural schematic diagram of another exemplary electronic device provided by the present disclosure, Figure 4 is a structural schematic diagram of an antenna structure provided by an embodiment of the present disclosure, and the electronic device 100 comprises a circuit board 2 and an antenna structure 1; the antenna structure 1 comprises a main branch 11 and a parasitic branch 12.

[0043] The circuit board 2 is provided with a feeding unit, and the feeding unit is used for feeding the main branch 11; the main branch 11 and the parasitic branch 12 are coplanarly arranged and respectively connected to the ground plate of the circuit board 2.

[0044] The parasitic branch 12 comprises a first radiation segment 121 and a second radiation segment 122 connected to each other; the main branch 11 and the first radiation segment 121 extend in the same direction, and a gap K is formed between the main branch 11 and the first radiation segment 121; the second radiation segment 122 is arranged in a bent manner relative to the first radiation segment 121.

[0045] It can be understood that the electronic device 100 described in the present disclosure can be a mobile phone, a tablet computer, a wearable device, a vehicle-mounted device, an augmented reality (AR) / virtual reality (VR) device, a notebook computer, an ultra-mobile personal computer (UMPC), a netbook, a personal digital assistant (PDA), etc. The above electronic devices can be stations (STAs) in a WLAN, and can be cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital processing (PDA) devices, handheld devices with wireless communication function, computing devices or other processing devices connected to wireless modems, computers, laptop computers, handheld communication devices, handheld computing devices, and / or other devices for communicating over wireless systems and next-generation communication systems, such as mobile terminals in a 5G network, mobile terminals in a future evolved public land mobile network (PLMN), or mobile terminals in a future evolved non-terrestrial network (NTN), etc.

[0046] By way of example and not limitation, when the electronic device described in the present disclosure is a wearable device, the wearable device can also be a general term for devices that can be worn and are designed and developed by applying wearable technology to daily wear, such as gloves, watches, AR (augmented reality) head-mounted display devices, VR (virtual reality) head-mounted display devices, or MR (mixed reality) head-mounted display devices, etc. configured with a long-range communication module and / or a short-range communication module.

[0047] The present disclosure will use a mobile phone as an exemplary electronic device to exemplarily illustrate the technical solutions of the present disclosure, and it should be understood that the mobile phone does not constitute any artificial limitation on the electronic device of the present disclosure.

[0048] The circuit board 2 is arranged in the housing of the electronic device 100, and the feeding unit can be a radio frequency system on the circuit board 2 or a radio frequency front-end part in the radio frequency system, and the feeding unit is used to provide a radio frequency signal and feed the corresponding feeding point of the main branch 11.

[0049] The circuit board 2 can be a PCB (Printed Circuit Board) board. The PCB board is a multi-layer dielectric board that is pressed together. There are metal plating layers in the multi-layer dielectric board. These metal plating layers can be used as the ground plate of the circuit board 2, and the ground plate can be used to ground the main branch 11 and the parasitic branch 12.

[0050] For the antenna structure 1, the antenna structure 1 can be arranged in or outside the shell, and can also be part of the shell. The main branch 11 and the parasitic branch 12 of the antenna structure 1 are arranged in the same plane. For example, the main branch 11 and the parasitic branch 12 are arranged on the same side of the shell of the electronic device 100, such as the length side or the width side of the electronic device 100.

[0051] For example, as shown in Figure 3 The electronic device 100 has a length side 3a and a width side 3b. The length side 3a and the width side 3b are perpendicular to each other. The length side 3a extends along the length direction of the electronic device 100, and the width side 3b extends along the width direction of the electronic device 100. The main branch 11 and the parasitic branch 12 are arranged on the length side 3a.

[0052] The main branch 11 and the first radiation segment 121 of the antenna structure 1 can be arranged along the length side 3a or the width side 3b of the electronic device 100. One end of the main branch 11 and one end of the first radiation segment 121 are close to each other to form a gap K between the main branch 11 and the first radiation segment 121. The gap K can be used to generate resonance through coupling effect, so that the excitation signal on the main branch 11 can be loaded to the parasitic branch 12 through the gap K. In actual applications, the width of the gap K between the main branch 11 and the first radiation segment 121 can be adjusted to adjust the coupling degree between the main branch 11 and the parasitic branch 12, so as to realize the matching tuning of the antenna.

[0053] For the parasitic branch 12, the second radiation segment 122 can be arranged to be bent at least once with respect to the extension direction of the first radiation segment 121, so as to realize the bent connection between the first radiation segment 121 and the second radiation segment 122.

[0054] In actual applications, the arrangement position and the bending form of the second radiation segment 122 with respect to the first radiation segment 121 can be set according to application requirements. The following is an example.

[0055] Exemplarily, the extending direction of the second radiating section 122 can be arranged at an angle with the extending direction of the first radiating section 121, so that the second radiating section 122 is bent once relative to the extending direction of the first radiating section 121, and the second radiating section 122 can be arranged at one end of the first radiating section 121 close to the gap K or at a middle region of the first radiating section 121 away from the gap K.

[0056] Exemplarily, the second radiating section 122 is arranged at an angle, and the extending direction of the part of the second radiating section 122 connected with the first radiating section 121 is arranged at an angle with the extending direction of the first radiating section 121, so that the second radiating section 122 is bent twice relative to the extending direction of the first radiating section 121, and the second radiating section 122 can be arranged at one end of the first radiating section 121 close to the gap K or at a middle region of the first radiating section 121 away from the gap K.

[0057] For the above two embodiments, since the second radiating section 122 is bent relative to the extending direction of the first radiating section 121, the radiating signal generates a component in the direction perpendicular to the extending direction of the first radiating section 121, and the component of the radiating signal in the direction parallel to the extending direction of the first radiating section 121 is correspondingly reduced, so that according to the feature of maintaining the continuity of the magnetic field lines on the boundary condition, the tangential component of the electromagnetic wave along the tissue fluid is correspondingly reduced.

[0058] Therefore, for the electronic device 100 shown in the present disclosure, by configuring the circuit board 2 and the antenna structure 1, the feeding unit on the circuit board 2 can feed the main branch 11 of the antenna structure 1, the gap K is formed between the main branch 11 and the first radiating section 121, and resonance is facilitated by the coupling effect, so that the excitation signal on the main branch 11 is loaded to the parasitic branch 12 through the gap K. Since the parasitic branch 12 includes the first radiating section 121 and the second radiating section 122 connected by bending, and the main branch 11 and the first radiating section 121 extend in the same direction, according to the wearing scene of the human body to the electronic device 100, the extending direction of the main branch 11 and the first radiating section 121 is usually parallel to the direction of the tissue fluid of the human body. This design can inversely increase the electric field component of the tissue fluid in the normal direction and reduce the electric field component of the tissue fluid in the tangential direction under the condition of the same efficiency, so as to realize the reduction of the specific absorption rate of the antenna structure 1 of the electronic device 100 when working.

[0059] In some embodiments, as Figure 5 shown, Figure 5is the simulation diagram of the current distribution on the parasitic branch when the antenna structure works in the resonant frequency band, when the feeding unit feeds the main branch 11, the parasitic branch 12 forms an excitation current under the magnetic field excitation of the main branch 11; the excitation current of the parasitic branch 12 flows from the first radiation section 121 to the second radiation section 122, or from the second radiation section 122 to the first radiation section 121, and the flow direction of the excitation current on at least part of the second radiation section 122 is opposite to that on the first radiation section 121.

[0060] It can be understood that when the feeding unit feeds the main branch 11, the excitation current on the parasitic branch 12 flows from the first radiation section 121 to the second radiation section 122 at the previous moment, and flows from the second radiation section 122 to the first radiation section 121 at the next moment, and then alternates in this rule in turn. Among them, Figure 5 The simulation arrow in the figure shows the scenario of the excitation current flowing from the first radiation section 121 to the second radiation section 122.

[0061] In actual application, when the parasitic branch 12 forms an excitation current under the magnetic field excitation of the main branch 11, the excitation current on the parasitic branch 12 flows along the first radiation section 121 to one side of the main branch 11 at a certain moment, and after the excitation current flows to the second radiation section 122, a part of the excitation current on the second radiation section 122 flows along the second radiation section 122 to the side away from the main branch 11, so as to realize that the flow direction of the excitation current on at least part of the second radiation section 122 is opposite to that on the first radiation section 121. The current reversal is the same, and will not be described here. This design makes the component of the radiation signal of the parasitic branch 12 in the extension direction of the main branch 11 weakened, realizes the reduction of the tangential electric field component of the tissue fluid, and the design of the parasitic branch 12 also partially offsets the component of the radiation signal in the direction perpendicular to the extension direction of the main branch 11, thereby effectively reducing the proportion of the component of the radiation signal of the parasitic branch 12 in the extension direction of the main branch 11, and achieving the purpose of reducing the specific absorption rate of the antenna structure 1 of the electronic device 100 when working.

[0062] In some embodiments, as shown in Figure 3 and Figure 4 , the main branch 11 has a feeding point F and a first grounding point G1, and the parasitic branch 12 has a second grounding point G2; the first grounding point G1 is arranged at the first end of the main branch 11, a gap K is formed between the second end of the main branch 11 and the first end of the first radiation section 121, one end of the second radiation section 122 is connected to the first end of the first radiation section 121, and the second grounding point G2 is arranged at the second end of the first radiation section 121; the feeding point F is arranged close to the first end of the main branch 11, the feeding unit feeds at the feeding point F, and the first grounding point G1 and the second grounding point G2 are respectively connected to the ground of the circuit board 2.

[0063] It can be understood that when the feeding unit feeds the main branch 11, the first grounding point G1 of the main branch 11 is formed as a first current strong point, and since the second end of the main branch 11 is an open end, the second end of the main branch 11 is formed as a first current weak point, which makes the main branch 11 form a first excitation current, the first excitation current flows from the first grounding point G1 to the second end of the main branch 11 at the previous moment, flows from the second end of the main branch 11 to the first grounding point G1 at the next moment, and periodically oscillates along the main branch 11 between the first grounding point G1 and the second end of the main branch 11 at the first target frequency band, that is, the main branch 11 resonates at the first target frequency band.

[0064] Correspondingly, the excitation signal on the main branch 11 is loaded to the parasitic branch 12 through the gap K, the second grounding point G2 of the parasitic branch 12 is formed as a second current strong point, and since the second end of the second radiation section 122 corresponding to the parasitic branch 12 is an open end away from the first radiation section 121, the second end of the second radiation section 122 is formed as a second current weak point, which makes the parasitic branch 12 form a second excitation current, the second excitation current flows from the second grounding point G2 to the second end of the second radiation section 122 at the previous moment, flows from the second end of the second radiation section 122 to the second grounding point G2 at the next moment, and periodically oscillates along the parasitic branch 12 between the second grounding point G2 and the second end of the second radiation section 122 at the second target frequency band, that is, the parasitic branch 12 resonates at the second target frequency band.

[0065] In actual work, when the main branch 11 resonates, since the second end of the main branch 11 is formed as a first current weak point and has a relatively large impedance, when the parasitic branch 12 is arranged, the second grounding point G2 of the parasitic branch 12 is arranged as far away from the second end of the main branch 11 as possible, which can ensure that the impedance of the end of the parasitic branch 12 close to the main branch 11 (that is, the impedance of the end of the first radiation section 121 close to the main branch 11) matches the impedance of the second end of the main branch 11, which also makes the antenna structure shown in the present disclosure have a relatively high antenna efficiency.

[0066] As Figure 3As shown, the distance between the first end and the second end of the main branch 11 is L11, which also represents the length of the main branch 11; the distance between the feeding point F of the main branch 11 and the second end of the main branch 11 is L12. Among them, the feeding point F of the main branch 11 is arranged at a position close to the first end of the main branch 11, that is, the feeding point F of the main branch 11 is close to the corresponding first grounding point G1 of the main branch 11. This design not only improves the impedance matching of the main branch 11, making it easier for the main branch 11 to match the corresponding feeder of the feeding unit and reduce reflection loss, but also facilitates better control of the current distribution on the main branch 11 and reduces the parasitic effect between the main branch 11 and the ground plane.

[0067] As shown in Figure 3 and Figure 4 As shown, the effective electrical length of the parasitic branch 12 is the distance between the second grounding point G2 of the parasitic branch 12 and the end of the parasitic branch 12, for example, according to Figure 4 The structure of the parasitic branch 12 is schematically shown, and the length of the parasitic branch 12 is the sum of the lengths of L21, L22 and L23.

[0068] In some embodiments, as shown in Figure 4 The second radiation section 122 includes a first bending section 1221 and a second bending section 1222; the first end of the first bending section 1221 is connected to the first radiation section 121, and the second end of the first bending section 1221 is connected to the first end of the second bending section 1222.

[0069] Among them, the second bending section 1222 and the first radiation section 121 are spaced apart from each other, and the second end of the second bending section 1222 extends and is arranged towards the side away from the main branch 11.

[0070] Specifically, in actual application, when the parasitic branch 12 forms an excitation current under the magnetic field excitation of the main branch 11, at the previous moment, the excitation current on the parasitic branch 12 will first flow along the first radiation section 121 towards the side of the main branch 11, and then flow from the first bending section 1221 to the second bending section 1222 of the second radiation section 122; at the next moment, the excitation current on the parasitic branch 12 will first flow from the second bending section 1222 to the first bending section 1221 of the second radiation section 122, and then flow along the first radiation section 121 towards the side away from the main branch 11 after the excitation current reaches the first radiation section 121, and then follow this rule alternately.

[0071] The structure of the first bending section 1221 and the second bending section 1222 can be configured as a straight line or an arc line. Alternatively, the structure of the first bending section 1221 and the second bending section 1222 can be configured as a straight line, the first bending section 1221 and the first radiation section 121 are arranged at an angle, the first bending section 1221 and the second bending section 1222 are arranged at an angle, for example, the extension direction of the first radiation section 121 and the extension direction of the first bending section 1221 form a first angle, the extension direction of the first bending section 1221 and the extension direction of the second bending section 1222 form a second angle, and the first angle and the second angle can be the same or different. For example, the first angle and the second angle are both right angles, or the first angle is a right angle and the second angle is an acute angle or an obtuse angle, or the first angle and the second angle are other suitable angles, which will not be listed one by one.

[0072] For example, as shown in FIG. 12A, the first bending section 1221 is arranged perpendicular to the first radiation section 121, and the second bending section 1222 is arranged parallel to the first radiation section 121. Figure 4

[0073] Further, as shown in FIG. 12B, the length of the extension of the second bending section 1222 is less than the length of the extension of the first radiation section 121. This design can utilize the reverse current formed on the second bending section 1222 relative to the first radiation section 121 to weaken the component of the radiation signal of the parasitic branch 12 in the extension direction of the main branch 11, and ensure that the direction of the component of the radiation signal of the parasitic branch 12 in the extension direction of the main branch 11 is consistent with the direction of the component of the main branch 11 in the extension direction thereof. Figure 4

[0074] In some embodiments, the effective electrical length extending between the first end and the second end of the main branch 11 corresponds to 1 / 4 of the working wavelength of the first target frequency band; the effective electrical length extending between the feeding point F and the second end of the main branch 11 is equal to 75%-85% of the length extending between the first end and the second end of the main branch 11; at the same time, the effective electrical length of the parasitic branch 12 in the extension direction thereof is 80%-120% of 1 / 4 of the working wavelength of the second target frequency band.

[0075] It can be understood that when the feeding unit feeds the main branch 11, the excitation signal on the main branch 11 is loaded to the parasitic branch 12 through the gap K, and the excitation signal on the parasitic branch 12 is generated, the excitation signal of the main branch 11 and the excitation signal of the parasitic branch 12 interact with each other, and electromagnetic waves of the target frequency band are generated. For example, the main branch 11 and the parasitic branch 12 interact with each other to generate electromagnetic waves of the N78 frequency band to realize 5G communication.

[0076] ​​In some embodiments, the difference between the frequency values corresponding to the first target frequency band and the second target frequency band is a set frequency, which ensures that the frequency value of the second target frequency band is greater than the frequency value of the first target frequency band, and compared with a single inverted-F antenna, the radiation efficiency of the antenna structure shown in the present disclosure can be effectively improved, and the influence of the parasitic branch on the overall efficiency of the antenna can be reduced.

[0077] For example, the size of the set frequency is 200MHz-300MHz, for example, the size of the set frequency can be 200MHz, 250MHz, 300MHz and other suitable frequencies.

[0078] As shown in Figure 3 , the distance between the first end and the second end of the main branch 11 is L11, and the distance between the feeding point F of the main branch 11 and the second end of the main branch 11 is L12, and the length of L12 can be 75%, 80% or 85% of the length of L11.

[0079] As shown in Figure 4 , the length L2 of the parasitic branch 12 along its extension direction is L21+L22+L23, and the length L2 can be 80%-120% of the 1 / 4 working wavelength of the second target frequency band.

[0080] In some embodiments, as shown in Figure 4 , the width of the gap K is 25%-50% of the length of the first bending section 1221.

[0081] Wherein, the width of the gap K is the width value of the gap K along the extension direction of the main branch 11, and the width of the gap K can be 25%, 30%, 40% or 50% of the length of L22.

[0082] In some embodiments, as shown in Figure 2 , the electronic device 100 further comprises a metal middle frame 3, and the metal middle frame 3 surrounds the periphery of the circuit board 2; the main branch 11 and the parasitic branch 12 are formed on one side of the metal middle frame 3.

[0083] Specifically, the electronic device 100 further comprises a back cover 4, and the back cover 4 is arranged on the first side of the metal middle frame 3, and the second side of the metal middle frame 3 is configured to arrange a display module, and the first side and the second side are two opposite sides. The circuit board 2 is arranged in the area defined by the metal middle frame 3, and the circuit board 2 is electrically connected with the display module.

[0084] At the same time, the metal middle frame 3 is provided with a break, and the break can be filled with plastic, and the metal middle frame 3 defines the main branch 11 and the parasitic branch 12 through the break, and the main branch 11 and the parasitic branch 12 can be arranged on the same side of the metal middle frame 3, for example, see Figure 3The main branch 11 and the parasitic branch 12 can be arranged on the length side 3a of the metal middle frame 3 or the width side 3b of the metal middle frame 3.

[0085] Exemplarily, the main branch 11 and the parasitic branch 12 are arranged on the length side of the metal middle frame 3, and a key is further arranged on the length side of the metal middle frame 3, and the key is electrically connected to the processor on the circuit board 2.

[0086] As shown in Figure 6 , Figure 7 and Figure 8 , Figure 6 is a SAR simulation schematic diagram of a screen surface of an electronic device when an antenna structure is working in a resonant frequency band, provided by an embodiment of the present disclosure, Figure 7 is a SAR simulation schematic diagram of a back cover surface of an electronic device when an antenna structure is working in a resonant frequency band, provided by an embodiment of the present disclosure, Figure 8 is a SAR simulation schematic diagram of a key surface of an electronic device when an antenna structure is working in a resonant frequency band, provided by an embodiment of the present disclosure, and when the antenna structure 1 is working in resonance, the SAR values of the screen surface 101, the back cover surface 102 and the key surface 103 of the electronic device 100 are simulated and tested, and the test data shown in Table 1 below can be obtained.

[0087] Table 1: Antenna SAR value test comparison table of the present application scheme and the reference scheme

[0088]

[0089] The antenna structure of the reference scheme also has a main branch and a parasitic branch coupled through a gap, but the parasitic branch is arranged to extend along the extension direction of the main branch.

[0090] As can be seen from Table 1, compared with the reference scheme, the SAR value of the present application scheme decreases by 27%, 26% and 23% on the screen surface, the back cover surface and the key surface of the electronic device, respectively, when the antenna structure is working in the resonant frequency band, which also illustrates the effectiveness of the SAR reduction of the present application scheme.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than limit them; although the present disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. An electronic device, comprising: The circuit board and an antenna structure; the antenna structure comprises a main branch and a parasitic branch; The circuit board is provided with a feeding unit, which is used for feeding the main branch; The main branch and the parasitic branch are coplanarly arranged and are respectively connected to the ground plate of the circuit board; The parasitic branch comprises a first radiation segment and a second radiation segment connected to each other; the main branch and the first radiation segment extend in the same direction, and a gap is formed between the main branch and the first radiation segment; the second radiation segment is arranged in a bent manner relative to the first radiation segment. 2.The electronic device of claim 1, wherein, When the feeding unit feeds the main branch, the parasitic branch forms an excitation current under the magnetic field excitation of the main branch; The excitation current of the parasitic branch flows from the first radiation segment to the second radiation segment, or from the second radiation segment to the first radiation segment; the flow direction of the excitation current of at least part of the segments on the second radiation segment is opposite to that of the excitation current on the first radiation segment. 3.The electronic device of claim 1, wherein, The main branch has a feeding point and a first grounding point, and the parasitic branch has a second grounding point; The first grounding point is arranged at the first end of the main branch, the gap is formed between the second end of the main branch and the first end of the first radiation segment, one end of the second radiation segment is connected to the first end of the first radiation segment, and the second grounding point is arranged at the second end of the first radiation segment; The feeding point is arranged close to the first end of the main branch, the feeding unit feeds at the feeding point, and the first grounding point and the second grounding point are respectively connected to the ground plate of the circuit board.

4. The electronic device of claim 3, wherein, The second radiation segment comprises a first bent segment and a second bent segment; The first end of the first bent segment is connected to the first radiation segment, and the second end of the first bent segment is connected to the first end of the second bent segment; The second bent segment and the first radiation segment are spaced apart from each other, and the second end of the second bent segment extends and is arranged towards a side away from the main branch.

5. The electronic device of claim 4, wherein, The length of the extension of the second bent segment is less than the length of the extension of the first radiation segment.

6. The electronic device of claim 4, wherein, The first bent segment is arranged perpendicularly to the first radiation segment, and the second bent segment is arranged in parallel to the first radiation segment.

7. The electronic device of any one of claims 3 to 6, wherein, The length of the extension between the first end and the second end of the main branch corresponds to 1 / 4 of the working wavelength of a first target frequency band; The length of the extension between the feeding point and the second end of the main branch is equal to 75% to 85% of the length of the extension between the first end and the second end of the main branch.

8. The electronic device of any one of claims 1 to 6, wherein, The length of the extension of the parasitic branch in the extension direction thereof is 80% to 120% of 1 / 4 of the working wavelength of a second target frequency band.

9. The electronic device of any one of claims 4 to 6, wherein, The width of the gap is 25% to 50% of the length of the first bent segment.

10. The electronic device of any one of claims 1 to 6, wherein, The electronic device further comprises a metal middle frame, which surrounds the circuit board; the main branch and the parasitic branch are formed on one side of the metal middle frame.

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