Electronic device

Abstract

The invention discloses electronic equipment. A first antenna unit comprises a first radiator, a second radiator and a first feed source; the first radiator comprises a first free end, a first feeding point and a second free end which are arranged in sequence; the second radiator is arranged on one side frame and comprises a third free end and a first grounding end which are arranged oppositely, the third free end is located between the first grounding end and the bottom frame, a first coupling gap is formed between the third free end and the second free end, and the first grounding end is grounded. The first feed source is electrically connected with the first feed point to excite the first radiator to form a first resonance mode supporting a first frequency band, the first feed source further excites the first radiator and the second radiator to form a second resonance mode supporting a Bluetooth frequency band, and the energy radiation direction of the second resonance mode is deviated to the side where the bottom frame is located. The Bluetooth communication quality is improved when the electronic equipment is located in the pocket, and the occupied space is reduced.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to an electronic device. Background Art

[0002] The usage environment of portable electronic devices such as mobile phones is complex. For example, when the electronic device is in a pocket and is communicating via Bluetooth, the electronic device is generally positioned with its bottom facing the ear. Due to the special posture of the electronic device and the influence of the environment in which the electronic device is located, problems such as unstable Bluetooth communication signals (such as freezing) are prone to occur when the electronic device is in a pocket. In addition, since the space in the electronic device is extremely limited, how to improve the quality of Bluetooth communication when the electronic device is in a pocket and reduce the space occupied is a technical problem that needs to be solved. Summary of the invention

[0003] The present application provides an electronic device that improves the Bluetooth communication quality when the electronic device is in a pocket and reduces the space occupied.

[0004] An electronic device provided in an embodiment of the present application includes:

[0005] A frame, the frame comprising a top frame, a bottom frame and a pair of side frames connected between the top frame and the bottom frame;

[0006] A first antenna unit, the first antenna unit includes a first radiator, a second radiator and a first feed source; the first radiator includes a first free end, a first feeding point and a second free end arranged in sequence; the second radiator is arranged on one of the side frames, the second radiator includes a third free end and a first grounding end arranged opposite to each other, and the third free end is located between the first grounding end and the bottom frame, a first coupling gap is formed between the third free end and the second free end, and the first grounding end is grounded; and

[0007] The first feed source is electrically connected to the first feeding point to excite the first radiator to form a first resonance mode supporting the first frequency band. The first feed source also excites the first radiator and the second radiator to form a second resonance mode supporting the Bluetooth frequency band. The energy radiation direction of the second resonance mode is biased toward the side where the bottom frame is located.

[0008] The electronic device provided by the present application includes a first radiator, a second radiator and a first feed source by setting a first antenna unit, the first radiator includes a first free end, a first feeding point and a second free end which are arranged in sequence; the second radiator is arranged on a side frame, the second radiator includes a third free end and a first grounding end which are arranged back to back, and the third free end is located between the first grounding end and the bottom frame, a first coupling gap is formed between the third free end and the second free end, and the first grounding end is grounded; the first feed source is electrically connected to the first feeding point to excite the first radiator to form a first resonance mode supporting the first frequency band, the first feed source also excites the first radiator and the second radiator to form a second resonance mode supporting the Bluetooth frequency band, the energy radiation direction of the second resonance mode is biased toward the side where the bottom frame is located, so that the electronic device can also perform good Bluetooth communication with wearable devices such as Bluetooth headsets when it is in pocket mode, and the signals of the Bluetooth frequency band and the first frequency band both reuse the first radiator, thereby improving the Bluetooth communication quality when the electronic device is in a pocket and reducing the space occupied. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments are briefly introduced below.

[0010] Figure 1 It is a structural schematic diagram of an electronic device provided in an embodiment of the present application;

[0011] Figure 2 It is a schematic diagram of a partial decomposition structure of an electronic device provided in an embodiment of the present application;

[0012] Figure 3 is a partial back view of an electronic device provided by an embodiment of the present application;

[0013] Figure 4 yes Figure 3 A schematic diagram of the structure of the antenna assembly;

[0014] Figure 5 is a structural schematic diagram of a first antenna assembly provided in an embodiment of the present application;

[0015] Figure 6 is a schematic structural diagram of a first matching circuit provided in an embodiment of the present application;

[0016] Figure 7 is a current distribution diagram of a first resonant mode of an antenna assembly provided in an embodiment of the present application;

[0017] Figure 8 is a current distribution diagram of the third resonance mode of the antenna assembly provided in an embodiment of the present application;

[0018] Fig. 9is a current distribution diagram of the second resonant mode of the antenna assembly provided in an embodiment of the present application;

[0019] Fig.10 yes Figure 3 A directional diagram of a first antenna unit provided on the frame in a Bluetooth frequency band;

[0020] Fig.11 yes Figure 5 An S-parameter curve of the first antenna unit is provided;

[0021] Fig.12 is a structural schematic diagram of a second antenna assembly provided in an embodiment of the present application;

[0022] Fig.13 yes Fig.12 A schematic diagram of the structure of the provided antenna assembly on an electronic device;

[0023] Fig.14 is an S-curve diagram of the switch tuning circuit provided in the embodiment of the present application switching the first antenna unit to support a sub-band of the first frequency band;

[0024] Fig.15 is a structural schematic diagram of an electronic device provided in an embodiment of the present application provided with a third type of antenna assembly;

[0025] Fig.16 is a structural schematic diagram of a third antenna assembly provided in an embodiment of the present application;

[0026] Fig.17 yes Fig.16 A current distribution diagram of a fourth resonant mode on the provided antenna assembly;

[0027] Fig.18 yes Fig.16 A current distribution diagram of a fifth resonant mode on the provided antenna assembly;

[0028] Fig.19 yes Fig.16 The S parameter curve of the second antenna unit is provided;

[0029] Fig. 20 is an S parameter diagram of a sub-band of MHB supported by the switch tuning circuit switching the second antenna unit provided in an embodiment of the present application;

[0030] Fig.21 is a schematic structural diagram of a second matching circuit provided in an embodiment of the present application;

[0031] Fig. 22 is a structural schematic diagram of a switch tuning circuit provided in an embodiment of the present application;

[0032] Fig.23is a specific structural diagram of a switch tuning circuit provided in an embodiment of the present application;

[0033] Fig.24a It is the isolation degree when the first antenna unit provided in the embodiment of the present application works in the B28 frequency band and works simultaneously with the second antenna unit;

[0034] Figure 24b It is the isolation degree when the first antenna unit provided in the embodiment of the present application works in the B5 frequency band and works simultaneously with the second antenna unit;

[0035] Fig.24c It is the isolation degree when the first antenna unit provided in the embodiment of the present application works in the B8 frequency band and works simultaneously with the second antenna unit;

[0036] Fig.25 is a schematic diagram of current distribution of a medium-high frequency current on a first antenna unit coupled to a second antenna unit provided by an embodiment of the present application;

[0037] Fig.26 is a specific structural diagram of another switch tuning circuit provided in an embodiment of the present application;

[0038] Fig. 27 is a schematic diagram of current distribution when the medium and high frequency current on the first antenna unit is not coupled to the second antenna unit provided in an embodiment of the present application;

[0039] Fig.28 is a comparison curve of isolation between a switch tuning circuit provided in an embodiment of the present application without a filter circuit and a switch tuning circuit provided with a filter circuit;

[0040] Fig.29 It is an S parameter and efficiency comparison curve of the first antenna unit provided in the embodiment of the present application in which no filtering circuit is set in the switch tuning circuit and a filtering circuit is set;

[0041] Fig.30 This is an efficiency comparison curve of the second antenna unit provided in the embodiment of the present application when no filtering circuit is set in the switch tuning circuit and when a filtering circuit is set.

[0042] Description of Figure Numbers:

[0043] Electronic device 1000; antenna assembly 100; display screen 200; middle frame 300; back cover 400; reference floor 500; middle plate 310; frame 320; top frame 321; bottom frame 322; first side frame 323; second side frame 324; main board 610; auxiliary circuit board 620; first reference ground edge 510; second reference ground edge 520; third reference ground edge 530; fourth reference ground edge 540; first antenna unit 100a; first radiator 10; second radiator 20; first feed source 30; first free end A, first feed point B; second free end C; third free end D; first ground end E; first coupling gap 41; first matching circuit M1; first inductor L1; matching unit P1; second inductor L2; first capacitor C1; connection point F; switch tuning Circuit T; second antenna unit 100b; third radiator 50; fourth radiator 60; second feed source 70; fourth free end G; connecting end H; fifth free end J; second feeding point N; second grounding end R; second matching circuit M2; second capacitor C2; third inductor L3; fourth inductor L4; fifth inductor L5; third capacitor C3; switch unit K; first tuning branch T1; second tuning branch T2; first end K1; second end K2; third end K3; first sub-end K21; second sub-end K22; third sub-end K23; first sub-branch T11; second sub-branch T12; third sub-branch T13; fourth sub-branch T14; fifth sub-branch T15; sixth sub-branch T16; seventh sub-branch T17; eighth sub-branch T18; ninth sub-branch T19; tenth sub-branch T20. DETAILED DESCRIPTION

[0044] The technical solution of the present application will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the embodiments described in the present application are only a part of the embodiments, not all of the embodiments. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present application.

[0045] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it mutually exclusive, independent, or alternative to other embodiments. It can be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0046] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example: a component or device including one or more parts is not limited to the one or more parts listed, but optionally includes one or more parts that are not listed but inherent to the exemplified product, or one or more parts that it should have based on the described function.

[0047] See also Figure 1 , Figure 1 The following is a schematic diagram of the structure of an electronic device 1000 provided in an embodiment of the present application. The electronic device 1000 includes but is not limited to a mobile phone, a tablet computer, a laptop computer, a computer, a smart wearable device, and other devices with communication functions. The present embodiment of the present application is described using a mobile phone as an example, and other electronic devices may refer to this embodiment.

[0048] See also Figure 2 , Figure 2 1 is a partially exploded schematic diagram of an electronic device 1000 provided in an embodiment of the present application. The electronic device 1000 includes an antenna assembly 100, and the working environment of the antenna assembly 100 is illustrated by taking the electronic device 1000 as a mobile phone as an example. The electronic device 1000 also includes a display screen 200, a middle frame 300 and a back cover 400 arranged in sequence along the thickness direction. Among them, the middle frame 300 includes a middle plate 310 and a frame 320 surrounding the side of the middle plate 310. The frame 320 may be a conductive frame. Of course, in other embodiments, the electronic device 1000 may not have a middle plate 310. The display screen 200, the middle plate 310 and the back cover 400 are stacked in sequence, and a receiving space is formed between the display screen 200 and the middle plate 310, and between the middle plate 310 and the back cover 400 to accommodate circuit boards 600 (main board 610, auxiliary circuit board 620), camera modules, receiver modules, batteries, various sensors and other devices. One side of the frame 320 is connected to the edge of the display screen 200, and the other side of the frame 320 is connected to the edge of the back cover 400 to form a complete appearance structure of the electronic device 1000. In this embodiment, the frame 320 and the middle plate 310 are an integrated structure, and the frame 320 and the back cover 400 are separate structures. The above is the working environment of the antenna assembly 100 taking a mobile phone as an example, but the antenna assembly 100 of the present application is not limited to the above working environment.

[0049] See also Figure 3 , Figure 33 is a back view of the electronic device 1000. The frame 320 includes a top frame 321 and a bottom frame 322 arranged relatively to each other, and a pair of side frames connected to the top frame 321 and the bottom frame 322, the pair of side frames being a first side frame 323 and a second side frame 324. The top frame 321 is the side away from the ground when the user holds the electronic device 1000 and uses the electronic device 1000 in portrait mode, and the bottom frame 322 is the side facing the ground when the user holds the electronic device 1000 and uses the electronic device 1000 in portrait mode. The first side frame 323 is the right side frame when the user holds the electronic device 1000 and uses the electronic device 1000 in portrait mode. The second side frame 324 is the left side frame when the user holds the electronic device 1000 and uses the electronic device 1000 in portrait mode. Of course, the first side frame 323 can also be the left side frame when the user holds the electronic device 1000 and uses the electronic device 1000. The second side frame 324 is the right side frame when the user holds the electronic device 1000 and uses the electronic device 1000. The top frame 321 and the bottom frame 322 are a pair of short sides, the first side frame 323 and the second side frame 324 are a pair of long sides, and the size of the long side is greater than that of the short side.

[0050] See also Figure 3 and Figure 4 The electronic device 1000 further includes a reference floor 500 . The reference floor 500 is disposed in the frame 320 .

[0051] The reference floor 500 includes but is not limited to the metal alloy portion (e.g., aluminum alloy) of the middle plate 310 and the reference ground metal portion of the circuit board 600 (including the main board 610 and the auxiliary circuit board 620). Generally speaking, the reference ground system in the electronic device 1000 can be equivalent to a roughly rectangular shape, so it is called the reference floor 500. The reference floor 500 does not indicate that the reference ground is in the shape of a plate and is a rectangular plate. The outer contour of the reference floor 500 is close to the inner side of the frame 320.

[0052] Taking the reference floor 500 as an example, the reference ground edge of the reference floor 500 includes but is not limited to a straight edge or a regular edge. Because devices are set up or other structures are avoided as needed in the mobile phone, various grooves, holes, etc. are opened on the reference ground edge of the reference floor 500.

[0053] See also Figure 3 The reference floor 500 includes a first reference ground edge 510, a second reference ground edge 520, a third reference ground edge 530 and a fourth reference ground edge 540 connected end to end in sequence. The first reference ground edge 510 and the third reference ground edge 530 are transverse edges. The second reference ground edge 520 and the fourth reference ground edge 540 are longitudinal edges.

[0054] See also Figure 3, the first reference ground edge 510 is opposite to and spaced from the top frame 321. The second reference ground edge 520 is opposite to and spaced from the first side frame 323. The third reference ground edge 530 is opposite to and spaced from the bottom frame 322. The fourth reference ground edge 540 is opposite to and spaced from the second side frame 324.

[0055] See also Figure 3 , the antenna assembly 100 includes a first antenna unit 100a.

[0056] See also Figure 4 The first antenna unit 100a includes a first radiator 10, a second radiator 20 and a first feed source 30.

[0057] Optionally, the first radiator 10 is made of conductive material, including but not limited to conductive materials such as metal and alloy.

[0058] The present application does not specifically limit the shape of the first radiator 10. For example, the shape of the first radiator 10 includes but is not limited to a strip, a sheet, a rod, a coating, a film, and the like. Figure 4 The shape of the first radiator 10 shown is only an example and does not limit the shape of the first radiator 10 provided in the present application. In this embodiment, the first radiator 10 is in a strip shape. In this embodiment, the first radiator 10 extends in a straight line or other trajectory. The first radiator 10 can be a line with uniform width on the extension trajectory, or a strip with unequal width such as a gradient width and a widened area.

[0059] The present application does not specifically limit the form of the first radiator 10. Optionally, the specific form of the first radiator 10 includes but is not limited to a metal frame 320, a metal frame embedded in a plastic frame 320, a metal conductor located in or on the frame 320, a flexible printed circuit board antenna formed on a flexible printed circuit board (FPC), a laser direct structured antenna by laser direct structure (LDS), a printed direct structured antenna by printing direct structure (PDS), a conductive sheet antenna (such as a metal bracket antenna), etc. The present application takes the first radiator 10 as a part of the frame 320 as an example.

[0060] See also Figure 3 and Figure 4, the first radiator 10 is arranged along the reference ground edge of the reference floor 500, and is spaced apart from the reference ground edge of the reference floor 500. The present application does not specifically limit the spacing between the first radiator 10 and the reference ground edge of the reference floor 500, for example, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, etc.

[0061] See also Figure 4 The first radiator 10 includes a first free end A, a first feeding point B and a second free end C which are arranged in sequence. The first free end A and the second free end C are two ends of the first radiator 10. The first free end A is one of the ends formed after an insulating break is formed on the frame. The second free end C is one of the ends formed after an insulating break is formed on the frame 320.

[0062] There is no specific limitation on the position of the first feeding point B between the first free end A and the second free end C. Optionally, the first feeding point B is located in the middle of the first radiator 10, that is, near the midpoint, so that the first radiator 10 forms a T-shaped antenna.

[0063] The second radiator 20 is disposed on one of the side frames 320. Optionally, the second radiator 20 is disposed on the first side frame 323. Further, the second radiator 20 is a part of the first side frame 323, and the second radiator 20 is spaced apart from the second reference ground edge 520.

[0064] See also Figure 4 The second radiator 20 includes a third free end D and a first ground end E which are arranged opposite to each other. The third free end D is an end after an insulating gap is arranged on the frame 320. The insulating gap is filled with insulating material to insulate the first free end AC1 from the frame 320 on the other side of the insulating gap and improve the overall structural strength of the frame 320.

[0065] The first grounding terminal E is grounded. The first grounding terminal E is the position where the first radiator 10 is electrically connected to the reference ground 500, and its electrical connection includes but is not limited to physical connection (integrated molding), electrical connection through conductive springs, conductive ejector pins, etc.

[0066] See also Figure 4 , the third free end D is located between the first ground end E and the bottom frame 322. A first coupling gap 41 is formed between the third free end D and the second free end C. In other words, the first radiator 10 is coupled to the second radiator 20, and the current signal on the first radiator 10 can be transmitted to the second radiator 20.

[0067] The first feed source 30 includes but is not limited to a port for an RF transceiver chip or an RF transceiver chip electrically connected. The first feed source 30 is used to provide an RF signal toward the first radiator 10. The first feed source 30 is arranged in a space surrounded by the frame 320. Specifically, the first feed source 30 is arranged on the main board 610 or the auxiliary circuit board 620. The first feed source 30 is electrically connected to the first feeding point B to excite the first radiator 10 to form a first resonant mode supporting the first frequency band. In other words, the resonant current of the first resonant mode supporting the first frequency band is distributed on the first radiator 10.

[0068] The present application does not limit the specific frequency band of the first frequency band. For example, the first frequency band includes but is not limited to at least one of the LB band (less than 1 GHz), the MHB band (1-3 GHz), the UHB band (greater than 3 GHz), the Wi-Fi band, the GPS band, etc.

[0069] The electrical connection between the first feed source 30 and the first feed point B includes, but is not limited to, direct electrical connection or coupled electrical connection. The connection medium of the direct electrical connection includes, but is not limited to, conductive springs, radio frequency connecting wires, conductive ejector pins, and the like.

[0070] The first feed source 30 also excites the first radiator 10 and the second radiator 20 to form a second resonance mode supporting the Bluetooth frequency band. In other words, the resonance current of the second resonance mode supporting the Bluetooth frequency band is distributed on the first radiator 10 and the second radiator 20.

[0071] Since the third free end D of the second radiator 20 is toward the side where the bottom frame 322 is located, the energy radiation direction of the second resonance mode is biased toward the side where the bottom frame 322 is located. Specifically, the energy radiation direction of the second resonance mode may be the direction from the top frame 321 to the bottom frame 322, or the angle between the energy radiation direction of the second resonance mode and the direction from the top frame 321 to the bottom frame 322 is less than 45°.

[0072] When the electronic device 1000 is in pocket mode, the bottom frame 322 of the electronic device 1000 faces the ears of the operator. The electronic device 1000 provided in the present application adds the first feed source 30 to the lower half of the whole machine to excite the Bluetooth antenna formed by the second radiator 20, and designs the directivity of the Bluetooth antenna to face the side where the bottom frame 322 is located, and the energy radiation direction of the Bluetooth signal of the first antenna unit 100a faces the side where the bottom frame 322 is located. When the electronic device 1000 is in pocket mode, since the directivity of the Bluetooth antenna faces the ears of the operator, compared with the directivity of the Bluetooth antenna arranged in the upper half of the whole machine facing the feet of the operator, it is more conducive to the electronic device 1000 to have good Bluetooth communication with Bluetooth communication devices such as Bluetooth headsets, and effectively solves the freeze problem when Bluetooth communication devices such as Bluetooth headsets receive incoming waves.

[0073] Of course, the electronic device 1000 also includes another Bluetooth antenna, the energy radiation direction of which is located at the top frame 321, the first side frame 323, the second side frame 324, etc. of the electronic device 1000. Furthermore, the directional patterns of the two Bluetooth antennas have different main radiation directions. Furthermore, the directional patterns of the two Bluetooth antennas are complementary or nearly complementary, so that when the bottom frame 322 of the electronic device 1000 is facing away from the operator, it can also perform good Bluetooth communication with Bluetooth communication devices such as Bluetooth headsets.

[0074] The first radiator 10 is coupled to the second radiator 20, and the excitation signal of the first feed source 30 can be transmitted to the second radiator 20 via the first radiator 10, so that the first feed source 30 can excite the second radiator 20 to form a resonant mode. Moreover, the first radiator 10 is multiplexed to support the first frequency band and the Bluetooth frequency band, which reduces the total size of the radiator while supporting the first frequency band and the Bluetooth frequency band, and reduces the space occupied by the first antenna unit 100a.

[0075] The electronic device 1000 provided in the present application comprises the first radiator 10, the second radiator 20 and the first feed source 30 by setting the first antenna unit 100a; the first radiator 10 comprises the first free end A, the first feeding point B and the second free end C which are arranged in sequence; the second radiator 20 is arranged on a side frame 320, the second radiator 20 comprises the third free end D and the first grounding end E which are arranged in opposite directions, and the third free end D is located between the first grounding end E and the bottom frame 322, the third free end D and the second free end C are provided with a first coupling gap 41, and the first grounding end E is connected to the first free end C. The first feed source 30 is electrically connected to the first feeding point B to excite the first radiator 10 to form a first resonance mode supporting the first frequency band. The first feed source 30 also excites the first radiator 10 and the second radiator 20 to form a second resonance mode supporting the Bluetooth frequency band. The energy radiation direction of the second resonance mode is biased toward the side where the bottom frame 322 is located, so that the electronic device 1000 can also perform good Bluetooth communication with wearable devices such as Bluetooth headsets when it is in pocket mode. The signals of the Bluetooth frequency band and the first frequency band both reuse the first radiator 10, thereby improving the Bluetooth communication quality of the electronic device 1000 when it is in a pocket and reducing the space occupied.

[0076] See also Figure 3 , Figure 3 It is a back view of the first antenna unit 100a provided in the present application, which is arranged on the frame 320. The second radiator 20 is located in the lower middle part of the first side 323. A part of the first radiator 10 is located on the first side 323, and another part of the first radiator 10 is located on the bottom 322. Generally, the bottom 322 is provided with a USB charging port. In order to adapt to the design of the USB charging port on the bottom 322, the first free end A of the first radiator 10 is adjacent to the USB charging port and is disconnected by an insulating break, and the insulating break is filled with insulating material. Among them, when the first ground terminal E is arranged adjacent to the battery, the first ground terminal E can be grounded by physically connecting to the reference floor 500.

[0077] The following takes the case where the first frequency band is the LB frequency band as an example to specifically describe the first antenna unit 100a.

[0078] See also Figure 5, the first antenna unit 100a also includes a first matching circuit M1. The first matching circuit M1 is electrically connected between the first radiator 10 and the first feed source 30. The first matching circuit M1 and the first feed source 30 are both arranged on an auxiliary circuit board. The first matching circuit M1 can be electrically connected to the first feeding point B through a feeding spring. The first matching circuit M1 is used to adjust the impedance matching between the first feed source 30 and the first radiator 10 so as to excite the first resonant mode and the second resonant mode, and then tune the LB band signal and the Bluetooth band signal based on the design of the structure and electrical length of the first radiator 10 and the second radiator 20. The first matching circuit M1 includes at least one of capacitors, inductors, resistors and other devices.

[0079] See also Figure 6 , the first matching circuit M1 includes a first inductor L1 and a matching unit P1.

[0080] One end of the first inductor L1 is electrically connected to the first feeding point B, and the other end of the first inductor L1 is grounded, so that the current of the first resonant mode is grounded from the first feeding point B through the first inductor L1. Both ends of the first radiator 10 are free ends, the first feeding point B is located near the center, and the first feeding point B is also grounded through the first inductor L1. In this way, the structure of the first radiator 10 is a T-type antenna, so as to excite the radiation mode and balanced mode of the T-type antenna and support the LB frequency band.

[0081] The present application does not specifically limit the size of the first inductor L1. In the present application, the signal of the first frequency band of the first resonance mode is grounded through the first inductor L1, and the first inductor L1 is a small inductor. For example, the inductance value of the first inductor L1 is 3.9-7.5nH.

[0082] The matching unit P1 is electrically connected (in series) between the first feeding point B and the first feed source 30 .

[0083] The matching unit P1 includes an inductor and / or a capacitor. The matching unit P1 is used to tune the resonant frequency position and bandwidth of the first resonant mode and the second resonant mode, so that the first resonant mode supports the LB frequency band, the second resonant mode supports the Bluetooth frequency band, and the Bluetooth frequency band has a wider bandwidth. Furthermore, the matching unit P1 is used to tune the resonant frequency of the first sub-mode to be close to the resonant frequency of the second sub-mode, and form a first continuous frequency band supporting the Bluetooth frequency band, thereby increasing the bandwidth of the Bluetooth frequency band.

[0084] Optionally, the resonant frequency of the matching unit P1 is less than the center frequency of the Bluetooth frequency band. The matching unit P1 is equivalent to a capacitive element for the Bluetooth frequency band. The first feed source 30 feeds the first radiator 10 through capacitive coupling to excite a higher-order mode of the 1-times wavelength mode of the Bluetooth frequency band on the first radiator 10, thereby forming a dual-wave resonance supporting the Bluetooth frequency band. The matching unit P1 also tunes the resonant frequency of the first sub-mode to be close to the resonant frequency of the second sub-mode, forming a first continuous frequency band supporting the Bluetooth frequency band, increasing the bandwidth of the Bluetooth frequency band, and increasing the anti-frequency deviation capability of the first antenna unit 100a in the Bluetooth frequency band.

[0085] For example, see Figure 6 The matching unit P1 includes a second inductor L2 and a first capacitor C1. The second inductor L2 is electrically connected between the first feeding point B and the first feed source 30, and the first capacitor C1 is connected between the first feeding point B and the first feed source 30.

[0086] The present application does not specifically limit the size of the second inductor L2. For example, the inductance value of the second inductor L2 is 3-5nH, for example, 4.3nH. The capacitance value of the first capacitor C1 is 1-3pF, for example, 1.8nH. The resonant frequency of the matching unit P1 is less than the center frequency of the Bluetooth frequency band, 2.45GHz. For example, the resonant frequency of the matching unit P1 is about 1.7GHz.

[0087] The above matching circuit structures are examples. The matching circuit structures provided in the present application include but are not limited to the above examples.

[0088] The first resonant mode of the first antenna unit 100a is described in detail below with reference to the accompanying drawings.

[0089] See also Figure 7 The resonant current of the first resonant mode includes a first sub-resonant current Q11 that is connected to the ground from the first free end A through the first feeding point B and a second sub-resonant current Q12 that is connected to the ground from the second free end C through the first feeding point B. The first sub-resonant current Q11 and the second sub-resonant current Q12 are both connected to the ground through the first inductor L1.

[0090] The electrical length between the first free end A and the first feeding point B is close to 1 / 4 wavelength of the first frequency band. The working mode of the first sub-resonant current Q11 corresponds to the 1 / 4 wavelength mode of the first frequency band. The electrical length between the second free end C and the first feeding point B is close to 1 / 4 wavelength of the first frequency band. The working mode of the second sub-resonant mode corresponds to the 1 / 4 wavelength mode of the first frequency band. The direction of the first sub-resonant current Q11 is opposite to the direction of the second sub-resonant current Q12.

[0091] See also Figure 8 , the first radiator 10 forms a third resonance mode supporting the second frequency band under the excitation of the feed source. The resonance frequency of the third resonance mode is greater than the resonance frequency of the first resonance mode. The resonance current of the third resonance mode is distributed between the first free end A and the second free end C. For example, it flows from the second free end C to the first free end A. In other words, the current from the second free end C to the first feeding point B is in the same direction as the current from the first feeding point B to the first free end A. The electrical length between the first free end A and the second free end C is close to 1 / 2 wavelength of the second frequency band. The third resonance mode corresponds to the 1 / 2 wavelength mode of the second frequency band.

[0092] The center frequency of the second frequency band is greater than the center frequency of the first frequency band, and the difference between the center frequency of the second frequency band and the center frequency of the first frequency band is less than 1 GHz.

[0093] In short, the first radiator 10 is a T-shaped antenna, and the first sub-resonant current Q11 formed in the first resonant mode from the first free end A to the first feeding point B is opposite to the second sub-resonant current Q12 generated from the first feeding point B to the second free end C. The first resonant mode is also called the radiation mode of the T-shaped antenna, and the radiation mode is relatively independent of the reference floor 500.

[0094] At the same time, the resonant current formed by the third resonant mode from the first free end A to the first feeding point B is in the same direction as the resonant current generated from the first feeding point B to the second free end C. The resonant current of the third resonant mode forms a current loop with the floor current on the reference floor 500. The third resonant mode is also called the balanced mode of the T-type antenna, and the balanced mode is a mode that depends on the participation of the reference floor 500. When the frequency band supported by the balanced mode is on the high-frequency side of the frequency band supported by the radiation mode, and the frequency band supported by the balanced mode is close to the frequency band supported by the radiation mode, the balanced mode can produce an efficiency enhancement effect (from the efficiency curve, the balanced mode can form an efficiency convex hull on the high-frequency side of the frequency band where the radiation mode is located) and thus improve the in-band efficiency of the radiation mode, that is, improve the in-band efficiency of the first frequency band.

[0095] Optional, see Fig. 9 The second resonant mode includes a first sub-mode and a second sub-mode. The first sub-mode includes a 1 / 4 wavelength mode of the Bluetooth frequency band formed on the second radiator 20. The resonant current Q22 of the first sub-mode is distributed on the second radiator 20.

[0096] Optionally, the electrical length between the third free end D and the first ground end E is close to 1 / 4 wavelength of the center frequency of the Bluetooth frequency band. The working mode of the resonant current Q22 of the first sub-mode is the 1 / 4 wavelength mode of the Bluetooth frequency band. The resonant current Q22 of the first sub-mode can flow from the third free end D to the first ground end E and go to the ground through the first ground end E. The 1 / 4 wavelength mode is the ground state mode of the monopole antenna, so the first antenna unit 100a has a higher radiation efficiency in the Bluetooth frequency band.

[0097] The electrical length described in this application can satisfy the following formula:

[0098]

[0099] Where L is the physical length, a is the transmission time of the electrical or electromagnetic signal in the medium, and b is the transmission time in free space.

[0100] The second sub-mode includes a 1-times wavelength mode of the Bluetooth frequency band formed on the first radiator 10. The resonant current Q21 of the second sub-mode is distributed on the first radiator 10.

[0101] Optionally, the electrical length between the first free end A and the second free end C is close to 1 wavelength of the center frequency of the Bluetooth frequency band. The working mode of the resonant current Q21 of the second sub-mode is the 1 wavelength mode of the Bluetooth frequency band. A part of the resonant current of the second sub-mode can flow from the midpoint of the first radiator 10 to the first free end A, and the current mode of this part is the 1 / 2 wavelength mode of the Bluetooth mode; another part of the resonant current of the second sub-mode can flow from the midpoint of the first radiator 10 to the second free end C, and the current mode of this part is the 1 / 2 wavelength mode of the Bluetooth mode.

[0102] Moreover, the resonance current Q22 of the first sub-mode is greater than the resonance current Q21 of the second sub-mode. That is, the first sub-mode is the main radiation mode of the second resonance mode. The first sub-mode determines the main radiation direction of the second resonance mode.

[0103] Among them, the resonant frequency of the first sub-mode coincides with or is close to the resonant frequency of the second sub-mode, and the first sub-mode and the second sub-mode enable the Bluetooth frequency band to have a wider bandwidth. In this way, even when the electronic device 1000 is frequency-deviation-free, the Bluetooth antenna can have better efficiency, so that the Bluetooth antenna of the electronic device 1000 can be used in various scenarios (for example, handheld scenarios, pocket scenarios, etc.).

[0104] See also Fig.10 , Fig.10 yes Figure 3The first antenna unit 100a provided on the frame 320 has a directional diagram in the Bluetooth frequency band. It can be seen that the main radiation direction of the first antenna unit 100a in the Bluetooth frequency band (as shown by the dotted arrow in the figure) is biased toward the side where the bottom frame 322 is located, wherein the main radiation direction of the first antenna unit 100a and the direction of the top frame 321 pointing to the bottom frame 322 have a small angle. When the operator puts the mobile phone into the pocket, the posture of the electronic device 1000 is that the bottom frame 322 is facing the pocket opening, triggering the pocket mode. At this time, the directional diagram of the Bluetooth antenna is facing the bottom frame 322, that is, the direction of the human ear, which is conducive to earphone reception and solves the jamming problem. When multiple Bluetooth antennas are provided in the electronic device 1000, the multiple Bluetooth antennas can work separately after switching, or they can work simultaneously. The switching trigger condition can be determined according to the strength of each Bluetooth antenna receiving and sending Bluetooth signals.

[0105] See also Fig.11 , Fig.11 yes Figure 5 The S parameter curve of the first antenna unit 100a is provided. As can be seen from the figure, the first antenna unit 100a forms a first resonant mode, a second resonant mode and a third resonant mode. Among them, the first resonant mode supports the LB frequency band, and the second resonant mode supports the Bluetooth frequency band. Among them, the resonant frequency band supported by the first sub-mode and the resonant frequency band supported by the second sub-mode form a first continuous frequency band, and the first continuous frequency band covers at least 2.4GHz-2.6GHz. Fig.11 The wave of the third resonance mode is not obvious.

[0106] For example, the resonant frequency band supported by the first sub-mode is the frequency band corresponding to the return loss of -4dB of the first sub-mode in the S parameter curve. The resonant frequency band supported by the second sub-mode is the frequency band corresponding to the return loss of -4dB of the second sub-mode in the S parameter curve. The frequency band corresponding to the return loss of -4dB of the first sub-mode in the S parameter curve and the frequency band corresponding to the return loss of -4dB of the second sub-mode in the S parameter curve form a continuous frequency band, which is named the first continuous frequency band. The first continuous frequency band covers at least 2.4GHz-2.6GHz. Fig.11 It can be seen that the first continuous frequency band covers at least 2.35GHz-2.6GHz. Since the Bluetooth frequency band is mainly 2.4-2.5GHz, and the bandwidth of a general Bluetooth antenna is less than 0.1GHz, the present application designs the structure and matching of the first antenna unit 100a to achieve dual-wave resonance of the Bluetooth frequency band to increase the bandwidth of the Bluetooth frequency band. For some pocket scenarios or other scenarios, even if the frequency deviation of the Bluetooth frequency band occurs, the efficiency is still good.

[0107] Optionally, the first frequency band is the LB frequency band. For example, the first frequency band mainly covers 700-900 MHz. The first antenna unit 100a provided in the present application is an LB+Bluetooth coexistence antenna, and improves the Bluetooth communication function in the pocket scenario and improves the anti-frequency deviation capability of the Bluetooth antenna.

[0108] Optional, see Fig.12 The first radiator 10 further includes a connection point F. The connection point F is located between the first free end A and the first feeding point B.

[0109] See also Fig.12 and Fig.13 , the electronic device 1000 also includes a switch tuning circuit T.

[0110] One end of the switch tuning circuit T is electrically connected to the connection point F, and the other end of the switch tuning circuit T is grounded. The switch tuning circuit T is used to switch the sub-band of the first frequency band. The first frequency band includes the LB frequency band. The sub-bands of the first frequency band include the B5 frequency band, the B8 frequency band, and the B28 frequency band. The switch tuning circuit T is used to switch the first antenna unit 100a to support the B5 frequency band, the B8 frequency band, or the B28 frequency band.

[0111] Optional, see Fig.12 , the distance between the connection point F and the first free end A is less than the distance between the connection point F and the first feeding point B. Further, the connection point F is close to the first free end A. Further, the distance between the connection point F and the first free end A is less than 1 / 8 wavelength of the first frequency band. Optionally, the connection point F may be located at the first free end A.

[0112] The connection point F to which one end of the switch tuning circuit T is electrically connected is approximately close to the first free end A. The wider the frequency adjustment range of the switch tuning circuit T is, the easier it is to tune the LB full frequency band. The LB full frequency band refers to the commonly used LB frequency band of 700-1000MHz.

[0113] See also Fig.14 , Fig.14 : is an S-curve diagram of the switch tuning circuit T provided in the embodiment of the present application switching the sub-band of the first frequency band supported by the first antenna unit 100a. Curve a is an S-curve when the switch tuning circuit T switches the sub-band of the first frequency band supported by the first antenna unit 100a to B28. Curve b is an S-curve when the switch tuning circuit T switches the sub-band of the first frequency band supported by the first antenna unit 100a to B5. Curve c is an S-curve when the switch tuning circuit T switches the sub-band of the first frequency band supported by the first antenna unit 100a to B8.

[0114] It can be seen that when the switch tuning circuit T switches the sub-bands of the first frequency band among the B5 frequency band, the B8 frequency band, and the B28 frequency band, the Bluetooth frequency band is in a permanent state.

[0115] Since the switch tuning circuit T is connected to the first radiator 10, and the main radiation mode (first sub-mode) of the Bluetooth frequency band is on the second radiator 20, the switch tuning circuit T covers the frequency band required for LB operation when tuning the sub-band of the first frequency band supported by the first resonance mode, and will not affect the first sub-mode on the second radiator 20, and thus will not affect the Bluetooth frequency band, and maintain the resident state and efficiency of the Bluetooth frequency band. Further, when the switch tuning circuit T switches the sub-band of the first frequency band between 700-1000MHz, the Bluetooth frequency band is in a resident state.

[0116] See also Fig.15 , the electronic device 1000 also includes a second antenna unit 100b.

[0117] See also Fig.16 The second antenna unit 100b includes a third radiator 50, a fourth radiator 60 and a second feed source 70. The third radiator 50 includes a fourth free end G and a connecting end H disposed opposite to each other. The fourth free end G and the connecting end H are two opposite ends of the third radiator 50.

[0118] The third radiator 50 and the fourth radiator 60 are both part of the bottom frame 322. The third radiator 50 is located between the second radiator 20 and the fourth radiator 60. The third radiator 50 is a section with a USB charging port. Specifically, both sides of the USB charging port of the bottom frame 322 are provided with insulating gaps to form the third radiator 50, so that a section of the USB charging port of the bottom frame 322 is effectively reused as an antenna radiator.

[0119] The connection end H is electrically connected to the switch tuning circuit T. The connection end H is grounded via the switch tuning circuit T.

[0120] See also Fig.16 The fourth radiator 60 includes a fifth free end J, a second feeding point N and a second grounding end R which are arranged in sequence. A second coupling gap is formed between the fifth free end J and the fourth free end G. The second feeding point N is electrically connected to the second feed source 70. The second grounding end R is grounded.

[0121] The fourth radiator 60 and the third radiator 50 form a mouth-to-mouth antenna, wherein the fourth radiator 60 is a main radiator and the third radiator 50 is a parasitic radiator.

[0122] See also Fig.17The second feed source 70 excites the second feeding point N and the second ground terminal R to form a fourth resonance mode supporting the third frequency band, and the resonance current of the fourth resonance mode flows from the second feeding point N to the ground through the second ground terminal R.

[0123] See also Fig.18 The second feed source 70 also excites the second feeding point N and the connection end H to form a fifth resonance mode supporting the fourth frequency band. The resonance current of the fifth resonance mode is connected to the ground through the switch tuning circuit T.

[0124] The second feed source 70 excites the fourth radiator 60 and the third radiator 50 to form different resonance modes, respectively, and support the fourth frequency band and the third frequency band, respectively. The third frequency band and the fourth frequency band both belong to the MHB frequency band. And the center frequency of the third frequency band is spaced from the center frequency of the fourth frequency band, for example, by 1 GHz. In this way, the third frequency band and the fourth frequency band can cover the entire MHB frequency band, so that the second antenna unit 100b can cover the entire MHB frequency band with a smaller size. The first antenna unit 100a is combined with the second antenna unit 100b, and the antenna assembly can realize the LB+MHB+Bluetooth coexistence antenna, providing protection for cellular communication.

[0125] Optionally, the second feeding point N is close to the fifth free end J, so that the first feed source 30 and the second feed source 70 can be compactly arranged on the auxiliary circuit board. Specifically, the distance between the second feeding point N and the fifth free end J is less than 1 / 10 wavelength of the third frequency band. For another example, the distance between the second feeding point N and the fifth free end J is less than 3mm. When the distance between the second feeding point N and the fifth free end J is too large, the laying area of ​​the auxiliary circuit board is large, which will result in insufficient space for the speaker arranged on one side of the auxiliary circuit board, which is not conducive to the overall layout.

[0126] For example, the electrical length between the second feeding point N and the second ground terminal R is or is close to 1 / 8 wavelength of the third frequency band. In addition, the second feed source 70 feeds the fourth radiator 60 by capacitive coupling feeding, and the electrical length between the second feeding point N and the second ground terminal R of the fourth radiator 60 satisfies the condition, so that the fourth resonance mode includes the 1 / 8 wavelength mode of the third frequency band. Further, the fourth resonance mode corresponds to the 1 / 8 wavelength mode (left-hand mode) of the third frequency band. The second feeding point N is closer to the location of the sixth free end, and it is easier to excite the left-hand mode. Among them, the third frequency band includes but is not limited to the B3 frequency band, or the B3+B40 frequency band, or the B40 frequency band, etc. Among them, since the electrical length between the second feeding point N and the second ground terminal R is or is close to 1 / 8 wavelength of the third frequency band, the size of the fourth radiator 60 is small, so the size of the radiator of the second antenna unit 100b is small.

[0127] The fifth resonance mode includes the 1 / 4 wavelength mode of the fourth frequency band. Further, the electrical length of the path from the second feeding point N and the connection end H through the switch tuning circuit T is close to 1 / 4 wavelength of the fourth frequency band. The fifth resonance mode corresponds to the 1 / 4 wavelength mode of the fourth frequency band.

[0128] The second antenna unit 100b forms a fourth resonance mode on the fourth radiator 60 and a fifth resonance mode on the third radiator 50. The dual-wave resonance can cover the full frequency band of MHB. Since the second antenna unit 100b is a mouth-to-mouth antenna and the fourth resonance mode is a 1 / 8 wavelength mode, the size of the second antenna unit 100b is relatively small. While realizing the LB+MHB+Bluetooth coexistence antenna, the space occupied by the second antenna unit 100b is also reduced.

[0129] See also Fig.15 The third radiator 50 and the fourth radiator 60 are both disposed on the bottom frame 322 .

[0130] See also Fig.15 , the electronic device 1000 further includes an auxiliary circuit board 620. The auxiliary circuit board 620 is arranged close to the second radiator 20 and the bottom frame 322. That is, the auxiliary circuit board 620 is arranged at the lower right corner in the rear view of the frame 320. The first feed source 30 and the second feed source 70 both adopt a compact design, so that the first feed source 30 and the second feed source 70 are both arranged on the auxiliary circuit board 620, reducing the space occupied by the auxiliary circuit board 620, reserving space for other functional components, and facilitating the layout of the whole machine.

[0131] See also Fig.19 , Fig.19 yes Fig.16 The S parameter curve of the second antenna unit 100b is provided. As can be seen from the figure, the first antenna unit 100a forms a fourth resonant mode and a fifth resonant mode. Among them, the third frequency band supported by the fourth resonant mode and the fourth frequency band supported by the fifth resonant mode form a second continuous frequency band. That is, the frequency band supported by the fourth resonant mode and the frequency band supported by the fifth resonant mode form a second continuous frequency band. The second continuous frequency band covers the MHB frequency band. The commonly used frequency band of the MHB frequency band is 1.5GHz-3GHz. The second continuous frequency band covers 1.5GHz-3GHz.

[0132] For example, the resonant frequency band supported by the fourth resonant mode is the frequency band corresponding to the return loss of -3dB of the fourth resonant mode in the S parameter curve. The resonant frequency band supported by the fifth resonant mode is the frequency band corresponding to the return loss of -3dB of the fifth resonant mode in the S parameter curve. Among them, the frequency band corresponding to the return loss of -3dB of the fourth resonant mode in the S parameter curve and the frequency band corresponding to the return loss of -3dB of the fifth resonant mode in the S parameter curve form a continuous frequency band, which is named the second continuous frequency band. The second continuous frequency band covers 1.5GHz-3GHz. Fig.19 It can be seen that the second continuous frequency band covers 1.5GHz-3GHz. Since the commonly used frequency band of the MHB frequency band is the second continuous frequency band covering 1.5GHz-3GHz, the present application designs the structure and matching of the second antenna unit 100b to realize that the second antenna unit 100b forms a double-wave resonance, covers the entire MHB frequency band, and reduces the space occupied by the second antenna unit 100b.

[0133] The switch tuning circuit T is also used to tune a sub-band of the second continuous frequency band. When the sub-band of the second continuous frequency band is switched, the Bluetooth frequency band is always resident.

[0134] The connection end H of the third radiator 50 is grounded through the switch tuning circuit T. When the switch tuning circuit T is switched, the electrical length of the path from the connection end H to the ground of the resonant current of the fifth resonant mode changes, and the resonant frequency of the fifth resonant mode changes. For example, as the capacitance value of the electrical length of the path from the connection end H to the ground of the resonant current of the fifth resonant mode decreases, the resonant frequency of the fifth resonant mode moves toward a low frequency.

[0135] See also Fig. 20 , Fig. 20 It is an S parameter diagram of the sub-band of MHB supported by the second antenna unit 100b switched by the switch tuning circuit T provided in the embodiment of the present application. Curve a is the S curve when the sub-band of MHB supported by the second antenna unit 100b switched by the switch tuning circuit T is B3+B1. Curve b is the S curve when the sub-band of MHB supported by the second antenna unit 100b switched by the switch tuning circuit T is B3+B40+B41. By switching the switch tuning circuit T, the efficiency of the second antenna unit 100b can be higher when operating in the B3+B1 frequency band, or the second antenna unit 100b can cover the B3+B40+B41 frequency band at the same time.

[0136] Also, see Fig.14, the switch tuning circuit T is also used to tune the sub-band of the first frequency band. When the switch tuning circuit T is switched, the electrical length of the resonant current of the first resonant mode on the path from the connection point F to the ground changes, and the resonant frequency of the first resonant mode changes. For example, as the inductance value of the electrical length of the resonant current of the first resonant mode on the path from the connection point F to the ground decreases, the resonant frequency of the first resonant mode moves toward high frequency.

[0137] The process of the switch tuning circuit T tuning the sub-band of the first frequency band and the process of tuning the sub-band of the second continuous frequency band are independent of each other, that is, the switching tuning circuit T tuning the sub-band of the LB frequency band and the sub-band of the MHB frequency band are independent of each other. In addition, whether the switch tuning circuit T tunes the sub-band of the LB frequency band or the sub-band of the MHB frequency band, it will not affect the Bluetooth frequency band supported by the second radiator 20, that is, the antenna assembly covers the entire LB frequency band and can realize the sub-band switching of the LB frequency band, and also improves the efficiency of the LB frequency band; the antenna assembly can also cover the entire MHB frequency band and can realize the sub-band switching of the MHB frequency band, keep the Bluetooth frequency band resident and have relatively good efficiency.

[0138] See also Fig.16 , the second antenna unit 100b also includes a second matching circuit M2. The second matching circuit M2 is electrically connected between the fourth radiator 60 and the second feed source 70. The second matching circuit M2 and the second feed source 70 are both arranged on the auxiliary circuit board 620. The second matching circuit M2 can be electrically connected to the second feeding point N through a feeding spring. The second matching circuit M2 is used to adjust the impedance matching between the second feed source 70 and the fourth radiator 60, so as to excite the fourth resonant mode and the fifth resonant mode, and then tune the MHB frequency band signal based on the design of the structure and electrical length of the fourth radiator 60 and the third radiator 50, and tune the position and bandwidth of the resonant frequency of the fourth resonant mode, and tune the position and bandwidth of the resonant frequency of the fifth resonant mode. The second matching circuit M2 includes at least one of capacitors, inductors, resistors and other devices.

[0139] See also Fig.21 The second matching circuit M2 includes a second capacitor C2, a third inductor L3, a fourth inductor L4, a fifth inductor L5 and a third capacitor C3.

[0140] One end of the second capacitor C2 is electrically connected to the second feeding point N. The other end of the second capacitor C2 is electrically connected to one end of the third inductor L3. The other end of the third inductor L3 is grounded.

[0141] One end of the fourth inductor L4 is electrically connected to the second feeding point N. The other end of the fourth inductor L4 is grounded; the fifth inductor L5 is electrically connected between the second feeding point N and the second feed source 70. The third capacitor C3 is electrically connected between the second feeding point N and the second feed source 70. The third capacitor C3 is connected in series between the second feed source 70 and the second feeding point N, so that the second feed source 70 excites the fourth radiator 60 by capacitive coupling feeding, so as to excite the fourth resonant mode.

[0142] The structure of the above second matching circuit M2 is conducive to tuning the position of the resonant frequency point of the fourth resonant mode to a suitable position, and adjusting the impedance bandwidth of the fourth resonant mode, and tuning the position of the resonant frequency point of the fifth resonant mode to a suitable position, and adjusting the impedance bandwidth of the fifth resonant mode, so that the frequency band supported by the fourth resonant mode and the frequency band supported by the fifth resonant mode cover the full MHB frequency band.

[0143] The above is an example of the structure of the second matching circuit M2. Of course, the second matching circuit M2 can also be other structures, which are not limited in this case, as long as the frequency band supported by the fourth resonance mode and the frequency band supported by the fifth resonance mode cover the full MHB frequency band.

[0144] For example, the capacitance value of the second capacitor C2 is in the range of 0.1-1 pF, for example, 0.3 pF. The inductance value of the third inductor L3 is in the range of 4-7 nH, for example, 5.6 nH. The inductance value of the fourth inductor L4 is in the range of 5-10 nH, for example, 7.5 nH. The inductance value of the fifth inductor L5 is in the range of 5-8 nH, for example, 6.2 nH. The capacitance value of the third capacitor C3 is in the range of 1-4 pF, for example, 2.2 pF.

[0145] Furthermore, a grounding capacitor Cn or a grounding inductor may be provided between the fifth inductor L5, the third capacitor C3 and the second feed source 70 to further tune the resonant frequency position and impedance bandwidth of the fourth resonant mode and further tune the resonant frequency position and impedance bandwidth of the fifth resonant mode.

[0146] See also Fig. 22 The switch tuning circuit T includes a switch unit K, a plurality of first tuning branches T1 and a plurality of second tuning branches T2.

[0147] See also Fig. 22 The switch unit K comprises a first terminal K1, at least one second terminal K2 and at least one third terminal K3. The first terminal K1 is grounded. Each of the first tuning branches T1 is electrically connected between the connection point F and one of the second terminals K2. Each of the second tuning branches T2 is electrically connected between the connection terminal H and one of the third terminals K3.

[0148] The switch unit K is used to select any one or more of the at least one second end K2 and the at least one third end K3 to be connected to the first end K1. The switch unit K is used to select any one or more of the multiple first tuning branches T1 and the multiple second tuning branches T2 to be grounded to tune the sub-band of the MHB frequency band and the sub-band of the LB frequency band.

[0149] Generally, the sub-band of the LB band in the first antenna unit 100a is tuned through an independent switching circuit, and the sub-band of the MHB band in the second antenna unit 100b is tuned through another independent switching circuit. Two independent switching circuits need to be provided with two switches, resulting in an increase in the cost of the antenna assembly. Based on this, the present application tunes the sub-band of the LB band in the first antenna unit 100a and the sub-band of the MHB band in the second antenna unit 100b through the same switching unit K, thereby reducing the design of one switching unit K and saving antenna costs.

[0150] On the basis that the antenna assembly provided in the present application has good low-frequency efficiency and bandwidth, the sub-band of the LB band covers the entire LB band (0.7-1GHz) after about three switches. The antenna assembly provided in the present application covers the entire MHB band (1.5-3GHz) through dual-wave resonance. The antenna assembly can switch the sub-band of MHB through about one switch, making the efficiency of certain sub-bands higher. Therefore, when designing the switch unit K as a single-pole four-throw switch (SP4T), one grounding path in the switch unit K can be used for the sub-band switching of MHB, and three grounding paths can be used for the sub-band switching of LB. In this way, the switch unit K is fully utilized to realize the common switch design of the first antenna unit 100a and the second antenna unit 100b, and the sub-band switching of MHB and the sub-band switching of LB are also realized.

[0151] Optional, see Fig.23 , the at least one second terminal K2 includes a first sub-terminal K21, a second sub-terminal K22 and a third sub-terminal K23.

[0152] See also Fig.23 The plurality of first tuning branches T1 include a first sub-branch T11, a second sub-branch T12, a third sub-branch T13 and a fourth sub-branch T14.

[0153] The first sub-branch T11 is electrically connected to the connection point F and the first sub-end K21.

[0154] One end of the second sub-branch T12 is electrically connected to an end of the first sub-branch T11 away from the connection point F, and the other end of the second sub-branch T12 is grounded.

[0155] The third sub-branch T13 is electrically connected between the connection point F and the second sub-end K22. The fourth sub-branch T14 is electrically connected between the connection point F and the third sub-end K23.

[0156] The number of the third end K3 is one.

[0157] See also Fig.23 The plurality of second tuning branches T2 include a fifth sub-branch T15, a sixth sub-branch T16, and a seventh sub-branch T17.

[0158] The fifth sub-branch T15 is electrically connected between the connection end H and the third end K3.

[0159] One end of the sixth sub-branch T16 is electrically connected to an end of the fifth sub-branch T15 away from the connection end H, and the other end of the sixth sub-branch T16 is grounded.

[0160] One end of the seventh sub-branch T17 is electrically connected to the connection end H, and the other end of the seventh sub-branch T17 is grounded.

[0161] The first sub-branch T11, the second sub-branch T12, the third sub-branch T13, the fourth sub-branch T14, and the sixth sub-branch T16 are all inductors, and the fifth sub-branch T15 and the seventh sub-branch T17 are all capacitors.

[0162] Specifically, the first sub-branch T11 is an inductor, and the inductance value of the first sub-branch T11 is 20-30 nH, for example, 22 nH.

[0163] Specifically, the second sub-branch T12 is an inductor, and the inductance value of the second sub-branch T12 is 15-20nH, for example, 18nH.

[0164] Specifically, the third sub-branch T13 is an inductor, and the inductance value of the third sub-branch T13 is 8-15nH, for example, 10nH.

[0165] Specifically, the fourth sub-branch T14 is an inductor, and the inductance value of the fourth sub-branch T14 is 3-8 nH, for example, 5.1 nH.

[0166] When the switch unit K switches to the first sub-end K21, the second sub-end K22, and the third sub-end K23 are all disconnected from the first end K1, the resonant current of the first resonant mode is grounded through the first sub-branch T11 and the second sub-branch T12. For example, at this time, the first antenna unit 100a operates in the B28 frequency band in the LB frequency band.

[0167] When the switch unit K switches the first sub-terminal K21 and the first terminal K1 to be sub-conductive, the resonant current of the first resonant mode is grounded through the first sub-branch T11. For example, at this time, the first antenna unit 100a operates in the B5 frequency band in the LB frequency band.

[0168] When the switch unit K is switched to the second sub-end K22 and the first end K1 are connected, the resonant current of the first resonant mode is grounded through the third sub-branch T13. For example, at this time, the first antenna unit 100a operates in the B8 frequency band in the LB frequency band.

[0169] When the switch unit K switches to the third sub-terminal K23 and the first terminal K1 to be sub-conductive, the resonant current of the first resonant mode goes to ground through the fourth sub-branch T14. For example, at this time, the first antenna unit 100a operates in a frequency band higher than the B8 frequency band in the LB frequency band.

[0170] In the above switching process, the resonant current of the first resonant mode of the switch unit K is grounded through different inductors, thereby changing the position of the resonant point of the first resonant mode, thereby tuning the position of the resonant point of the first frequency band, and switching the sub-band of the LB frequency band.

[0171] Specifically, the fifth sub-branch T15 is a capacitor, and the capacitance value of the fifth sub-branch T15 is 0.5-2 pF, for example, 1 pF.

[0172] Specifically, the sixth sub-branch T16 is an inductor, and the inductance value of the sixth sub-branch T16 is 50-150nH, for example, 100nH.

[0173] Specifically, the seventh sub-branch T17 is a capacitor, and the inductance value of the seventh sub-branch T17 is 0-1 pF, for example, 0.3 pF.

[0174] The sixth sub-branch T16 is a large inductor, and when the switch unit K is switched to the third end K3 and the first end K1 is turned on, the sixth sub-branch T16 is short-circuited, and the resonant current of the fifth resonant mode is grounded through the fifth sub-branch T15 and the switch unit K. For example, at this time, the first antenna unit 100a operates in the B3+B1 frequency band in the MHB frequency band.

[0175] When the switch unit K is switched to the third end K3 and disconnected from the first end K1, since the sixth sub-branch T16 is a large inductor, it is equivalent to a circuit break. Therefore, the resonant current of the fifth resonant mode is grounded through the seventh sub-branch T17. For example, at this time, the first antenna unit 100a operates in the B3+B40+B41+B1 frequency band in the MHB frequency band.

[0176] When the switch unit K switches to the third end K3 and the first end K1 to be turned on or off, the resonant current of the fifth resonant mode goes to ground through different capacitors, thereby changing the resonant point position of the fifth resonant mode, thereby tuning the resonant point position of the fourth frequency band, and switching the sub-band of the MHB band.

[0177] See also Figure 24a-Figure 24c , Fig.24a It is the isolation degree when the first antenna unit 100a works in the B28 frequency band and works simultaneously with the second antenna unit 100b. In the figure, curve S1,1 represents the S parameter curve of the first antenna unit 100a. Curve S2,2 represents the S parameter curve of the second antenna unit 100b. Curve S1,2 represents the isolation curve of the first antenna unit 100a to the second antenna unit 100b. Curve S2,1 represents the isolation curve of the second antenna unit 100b to the first antenna unit 100a.

[0178] Figure 24b It is the isolation degree when the first antenna unit 100a works in the B5 frequency band and works simultaneously with the second antenna unit 100b. Curve S1,1 represents the S parameter curve of the first antenna unit 100a. Curve S2,2 represents the S parameter curve of the second antenna unit 100b. Curve S1,2 represents the isolation degree curve of the first antenna unit 100a to the second antenna unit 100b. Curve S2,1 represents the isolation degree curve of the second antenna unit 100b to the first antenna unit 100a.

[0179] Fig.24c It is the isolation when the first antenna unit 100a works in the B8 frequency band and works simultaneously with the second antenna unit 100b. Curve S1,1 represents the S parameter curve of the first antenna unit 100a. Curve S2,2 represents the S parameter curve of the second antenna unit 100b. Curve S1,2 represents the isolation curve of the first antenna unit 100a to the second antenna unit 100b. Curve S2,1 represents the isolation curve of the second antenna unit 100b to the first antenna unit 100a.

[0180] It can be seen that the isolation between the first antenna unit 100a and the second antenna unit 100b is relatively high in the LB frequency band, that is, the low-frequency signal in the second antenna unit 100b will not affect the first antenna unit 100a.

[0181] As the first antenna unit 100a switches from the B28 band to the B8 band, the isolation between the first antenna unit 100a and the second antenna unit 100b at 2.7 GHz (MHB-B41) deteriorates severely, from -9.8 dB to -7.1 dB. The deterioration of isolation affects the efficiency of MHB. In addition, a high suppression filter needs to be added at the RF end for optimization, which increases the cost. This indicates that part of the medium and high frequency signals in the first antenna unit 100a pass through the insulation gap to the second antenna unit 100b.

[0182] See also Fig.25 , Fig.25 It is a schematic diagram of current distribution when the medium and high frequency current on the first antenna unit 100a is coupled to the second antenna unit 100b.

[0183] The switch tuning circuit T provided in the present application can also improve the isolation between the first antenna unit 100a and the second antenna unit 100b in the MHB frequency band. The switch tuning circuit T also includes at least one filter branch.

[0184] One end of the at least one filter branch is electrically connected to at least one of the first tuning branches T1, and the other end of the filter branch is electrically connected to the second end K2 or grounded. The filter branch is used to conduct the resonant current of the MHB band to the ground. When the medium and high frequency current of the first antenna unit 100a flows to the connection point F, the medium and high frequency current is grounded through the filter branch to prevent the medium and high frequency current of the first antenna unit 100a from flowing to the first connection end H, affecting the second antenna unit 100b, especially affecting the fifth resonant mode, thereby improving the isolation between the first antenna unit 100a and the second antenna unit 100b at medium and high frequencies.

[0185] See also Fig.26 , the at least one filter branch includes an eighth sub-branch T18, a ninth sub-branch T19 and a tenth sub-branch T20. One end of the eighth sub-branch T18 is electrically connected to one end of the first sub-branch T11, and the other end of the eighth sub-branch is electrically connected to the other end of the second sub-branch T12. The eighth sub-branch T18 is a filter branch for filtering medium and high frequency signals when the resonant current of the first resonant mode flows through the first sub-branch T11 / the second sub-branch T12. The eighth sub-branch T18 includes a capacitor.

[0186] See also Fig.26, one end of the ninth sub-branch T19 is electrically connected to one end of the third sub-branch T13, and the other end of the ninth sub-branch T19 is electrically connected to the second sub-end K22. The ninth sub-branch T19 is a filtering branch for filtering medium and high frequency signals when the resonant current of the first resonant mode flows through the third sub-branch T13. The ninth sub-branch T19 includes a capacitor. The LC parallel resonant circuit formed by the ninth sub-branch T19 and the third sub-branch T13 has a resonant frequency less than 2.7 GHz and greater than the LB frequency band. For example, the resonant frequency of the LC parallel resonant circuit is 1 GHz.

[0187] See also Fig.26 , one end of the tenth sub-branch T20 is electrically connected to one end of the fourth sub-branch T14. The other end of the tenth sub-branch T20 is electrically connected to the third sub-terminal K23. The tenth sub-branch T20 is a filtering branch for filtering medium and high frequency signals when the resonant current of the first resonant mode flows through the fourth sub-branch T14. The tenth sub-branch T20 includes a capacitor. The tenth sub-branch T20 and the fourth sub-branch T14 form an LC parallel resonant circuit, and the resonant frequency of the resonant circuit is less than 2.7 GHz and greater than the LB frequency band. For example, the resonant frequency of the LC parallel resonant circuit is 1 GHz.

[0188] For the low frequency band, due to the characteristics of the LC parallel resonant circuit (the resonant frequency of the LC parallel resonant circuit is greater than the LB band), the low frequency current of the first antenna unit 100a still passes through the branch where the inductor is located to support the switching of the LB band and the sub-bands of the LB band. For the medium and high frequency (2.7GHz) band, since the resonant frequency of the LC parallel resonant circuit is lower than the medium and high frequency (2.7GHz) band, the medium and high frequency current of the first antenna unit 100a will pass through the capacitor in the LC parallel resonant circuit to the ground (when the switch unit K is turned on), and will not be coupled to the third radiator 50 of the second antenna unit 100b, thereby improving the isolation and efficiency of the first antenna unit 100a and the second antenna unit 100b at the medium and high frequencies. The switch tuning circuit T provided in the present application forms an LC resonant circuit by adding a filtering branch to each branch of the LB resonant current, thereby weakening the influence of the medium and high frequency currents on the first antenna unit 100a on the second antenna unit 100b, thereby achieving high isolation between the ports of the first antenna unit 100a and the second antenna unit 100b.

[0189] See also Fig. 27 , Fig. 27 It is a schematic diagram of current distribution when the medium and high frequency current on the first antenna unit 100a is not coupled to the second antenna unit 100b provided in an embodiment of the present application.

[0190] See also Fig.28 , Fig.281 is a comparison curve of the isolation between the switch tuning circuit T provided in the embodiment of the present application without a filter circuit and with a filter circuit. Curve a is the isolation curve when the first antenna unit 100a works in the B5 frequency band and the filter circuit is set in the switch tuning circuit T. Curve b is the isolation curve when the first antenna unit 100a works in the B5 frequency band and the filter circuit is not set in the switch tuning circuit T.

[0191] Curve c is an isolation curve when the first antenna unit 100a operates in the B8 frequency band and a filter circuit is provided in the switch tuning circuit T. Curve d is an isolation curve when the first antenna unit 100a operates in the B8 frequency band and a filter circuit is not provided in the switch tuning circuit T.

[0192] Curve e is an isolation curve when the first antenna unit 100a operates in the B28 frequency band and a filter circuit is provided in the switch tuning circuit T. Curve f is an isolation curve when the first antenna unit 100a operates in the B28 frequency band and no filter circuit is provided in the switch tuning circuit T.

[0193] It can be seen that after the filter circuit is set in the switch tuning circuit T, the isolation between the first antenna unit 100a and the second antenna unit 100b is improved by a maximum of 10 dB, ensuring that the high isolation requirement is basically achieved within the full frequency range of 0-3 GHz.

[0194] See also Fig.29 , Fig.29 It is an S parameter and efficiency comparison curve of the first antenna unit 100a provided in the embodiment of the present application when no filtering circuit is set in the switch tuning circuit T and when a filtering circuit is set.

[0195] Curve a1 is an S parameter curve when the first antenna unit 100a operates in the B5 frequency band and a filter circuit is provided in the switch tuning circuit T. Curve b1 is an S parameter curve when the first antenna unit 100a operates in the B5 frequency band and no filter circuit is provided in the switch tuning circuit T.

[0196] Curve c1 is an S parameter curve when the first antenna unit 100a operates in the B8 frequency band and a filter circuit is provided in the switch tuning circuit T. Curve d1 is an S parameter curve when the first antenna unit 100a operates in the B8 frequency band and no filter circuit is provided in the switch tuning circuit T.

[0197] Curve e1 is an S parameter curve when the first antenna unit 100a operates in the B28 frequency band and a filter circuit is provided in the switch tuning circuit T. Curve f1 is an S parameter curve when the first antenna unit 100a operates in the B28 frequency band and a filter circuit is not provided in the switch tuning circuit T.

[0198] Curve a2 is the total efficiency curve of the first antenna unit 100a operating in the B5 frequency band and a filter circuit is provided in the switch tuning circuit T. Curve b2 is the total efficiency curve of the first antenna unit 100a operating in the B5 frequency band and a filter circuit is not provided in the switch tuning circuit T.

[0199] Curve c2 is the total efficiency curve of the first antenna unit 100a operating in the B8 frequency band and a filter circuit is provided in the switch tuning circuit T. Curve d2 is the total efficiency curve of the first antenna unit 100a operating in the B8 frequency band and a filter circuit is not provided in the switch tuning circuit T.

[0200] Curve e2 is the total efficiency curve of the first antenna unit 100a operating in the B28 frequency band and a filter circuit is provided in the switch tuning circuit T. Curve f2 is the total efficiency curve of the first antenna unit 100a operating in the B28 frequency band and a filter circuit is not provided in the switch tuning circuit T.

[0201] It can be seen that after the filter circuit is provided in the switch tuning circuit T, the first antenna unit 100a can well achieve high performance in both the LB frequency band and the Bluetooth frequency band.

[0202] See also Fig.30 , Fig.30 This is an efficiency comparison curve of the second antenna unit 100b provided in the embodiment of the present application when no filtering circuit is provided in the switch tuning circuit T and when a filtering circuit is provided.

[0203] Curve a is a total efficiency curve when the second antenna unit 100b operates in the MHB frequency band, the first antenna unit 100a operates in the B5 frequency band, and a filter circuit is set in the switch tuning circuit T.

[0204] Curve b is a total efficiency curve when the second antenna unit 100b operates in the MHB frequency band, the first antenna unit 100a operates in the B5 frequency band, and no filtering circuit is provided in the switch tuning circuit T.

[0205] Curve c is a total efficiency curve when the second antenna unit 100b operates in the MHB frequency band, the first antenna unit 100a operates in the B8 frequency band, and a filter circuit is provided in the switch tuning circuit T.

[0206] Curve d is a total efficiency curve when the second antenna unit 100b operates in the MHB frequency band, the first antenna unit 100a operates in the B8 frequency band, and no filtering circuit is provided in the switch tuning circuit T.

[0207] Curve e is a total efficiency curve when the second antenna unit 100b operates in the MHB frequency band, the first antenna unit 100a operates in the B28 frequency band, and a filter circuit is set in the switch tuning circuit T.

[0208] Curve f is a total efficiency curve when the second antenna unit 100b operates in the MHB frequency band, the first antenna unit 100a operates in the B28 frequency band, and no filtering circuit is provided in the switch tuning circuit T.

[0209] It can be seen that after setting the filtering circuit in the switch tuning circuit T, the maximum improvement at 2.7GHz (MHB-B41) is 1.4dB, which effectively ensures the performance of mid- and high-frequency.

[0210] The electronic device 1000 provided in the present application comprises the first radiator 10, the second radiator 20 and the first feed source 30 by setting the first antenna unit 100a; the first radiator 10 comprises the first free end A, the first feeding point B and the second free end C which are arranged in sequence; the second radiator 20 is arranged on a side frame 320, the second radiator 20 comprises the third free end D and the first grounding end E which are arranged in opposite directions, and the third free end D is located between the first grounding end E and the bottom frame 322, the third free end D and the second free end C are provided with a first coupling gap 41, and the first grounding end E is connected to the first free end C. The first feed source 30 is electrically connected to the first feeding point B to excite the first radiator 10 to form a first resonance mode supporting the first frequency band. The first feed source 30 also excites the first radiator 10 and the second radiator 20 to form a second resonance mode supporting the Bluetooth frequency band. The energy radiation direction of the second resonance mode is biased toward the side where the bottom frame 322 is located, so that the electronic device 1000 can also perform good Bluetooth communication with wearable devices such as Bluetooth headsets when it is in pocket mode. The signals of the Bluetooth frequency band and the first frequency band both reuse the first radiator 10, thereby improving the Bluetooth communication quality of the electronic device 1000 when it is in a pocket and reducing the space occupied.

[0211] The present application provides a low-cost, high-isolation LB+MHB+BT coexistence antenna design, which supports the LB frequency band through the radiation mode and balanced mode of the T-type antenna, thereby improving the efficiency of the LB frequency band; the T-type antenna and its parasitic antenna are designed to form a resonant mode to support the Bluetooth frequency band, thereby improving the efficiency of the Bluetooth frequency band and increasing the bandwidth; the Bluetooth antenna is arranged in the lower half of the entire electronic device 1000, and the radiation pattern of the Bluetooth antenna is toward the bottom frame 322, so as to provide hardware support for optimizing the performance of the scenario in which the user puts the mobile phone in the pocket and uses Bluetooth; the first antenna unit 100a and the second antenna unit 100b share a switch tuning circuit T to achieve coverage of the full frequency band of LB + full frequency band of MHB + full frequency band of Bluetooth, thereby saving costs and realizing cellular communication functions and Bluetooth communication functions; a high isolation between LB and MHB is achieved by forming an LC resonant circuit, thereby improving the performance of LB+MHB+Bluetooth.

[0212] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present application, and these improvements and modifications are also regarded as the scope of protection of the present application.

Claims

1. An electronic device, characterized in that: include: A frame, the frame comprising a top frame, a bottom frame and a pair of side frames connected between the top frame and the bottom frame; A first antenna unit, the first antenna unit includes a first radiator, a second radiator and a first feed source; the first radiator includes a first free end, a first feeding point and a second free end arranged in sequence; the second radiator is arranged on one of the side frames, the second radiator includes a third free end and a first grounding end arranged opposite to each other, and the third free end is located between the first grounding end and the bottom frame, a first coupling gap is formed between the third free end and the second free end, and the first grounding end is grounded; and The first feed source is electrically connected to the first feeding point to excite the first radiator to form a first resonance mode supporting the first frequency band. The first feed source also excites the first radiator and the second radiator to form a second resonance mode supporting the Bluetooth frequency band. The energy radiation direction of the second resonance mode is biased toward the side where the bottom frame is located.

2. The electronic device according to claim 1, wherein: The second resonance mode includes a first sub-mode and a second sub-mode, the first sub-mode includes a 1 / 4 wavelength mode of the Bluetooth frequency band formed on the second radiator, and the second sub-mode includes a 1 times wavelength mode of the Bluetooth frequency band formed on the first radiator.

3. The electronic device according to claim 2, characterized in that: The resonance frequency band supported by the first sub-mode and the resonance frequency band supported by the second sub-mode form a first continuous frequency band, and the first continuous frequency band at least covers 2.4 GHz-2.6 GHz.

4. The electronic device according to claim 1, wherein: The resonant current of the first resonant mode includes a first sub-resonant current from the first free end through the first feeding point to the ground and a second sub-resonant current from the second free end through the first feeding point to the ground. The working mode of the first sub-resonant current corresponds to the 1 / 4 wavelength mode of the first frequency band, and the working mode of the second sub-resonant current corresponds to the 1 / 4 wavelength mode of the first frequency band.

5. The electronic device according to claim 4, characterized in that: The first radiator forms a third resonance mode supporting the second frequency band under the excitation of the feed source, the resonance frequency of the third resonance mode is greater than the resonance frequency of the first resonance mode, the resonance current of the third resonance mode is distributed between the first free end and the second free end, and the third resonance mode corresponds to the 1 / 2 wavelength mode of the second frequency band.

6. The electronic device according to claim 4, characterized in that: The first antenna unit further includes a first matching circuit, the first matching circuit includes a first inductor and a matching unit, one end of the first inductor is electrically connected to the first feeding point, the other end of the first inductor is grounded, and the first sub-resonant current and the second sub-resonant current are both grounded via the first inductor; The matching unit is electrically connected between the first feeding point and the first feed source, the matching unit includes an inductor and / or a capacitor, and the matching unit is used to tune the resonant frequency and bandwidth of the first resonant mode and the second resonant mode.

7. The electronic device according to claim 6, characterized in that: The resonant frequency of the matching unit is lower than the central frequency of the Bluetooth frequency band, and the matching unit is equivalent to a capacitive element for the Bluetooth frequency band.

8. The electronic device according to claim 7, characterized in that: The matching unit includes a second inductor and a first capacitor, the second inductor is electrically connected between the first feeding point and the first feed source, and the first capacitor is connected between the first feeding point and the first feed source.

9. The electronic device according to claim 1, wherein: The first radiator further includes a connection point, wherein the connection point is located between the first free end and the first feeding point; The electronic device also includes a switch tuning circuit, one end of which is electrically connected to the connection point, and the other end of which is grounded. The switch tuning circuit is used to switch sub-bands of the first frequency band, and the first frequency band includes the LB band.

10. The electronic device according to claim 9, characterized in that: The electronic device further comprises a second antenna unit, the second antenna unit comprises a third radiator, a fourth radiator and a second feed source, the third radiator comprises a fourth free end and a connecting end arranged opposite to each other, the connecting end is electrically connected to the switch tuning circuit; The fourth radiator comprises a fifth free end, a second feeding point and a second grounding end which are arranged in sequence, a second coupling gap is formed between the fifth free end and the fourth free end, the second feeding point is electrically connected to the second feed source, and the second grounding end is grounded; The second feed source excites the second feeding point and the second grounding end to form a fourth resonance mode supporting the third frequency band, and excites the second feeding point and the connecting end to form a fifth resonance mode supporting the fourth frequency band, and the resonance current of the fifth resonance mode is grounded through the switch tuning circuit.

11. The electronic device according to claim 10, characterized in that: The distance between the second feeding point and the fifth free end is less than 1 / 10 wavelength of the third frequency band, and the second feed source feeds the fourth radiator by capacitive coupling feeding; the fourth resonance mode includes a 1 / 8 wavelength mode of the third frequency band; and the fifth resonance mode includes a 1 / 4 wavelength mode of the fourth frequency band.

12. The electronic device according to claim 11, characterized in that: The third radiator and the fourth radiator are both arranged on the bottom frame; The electronic device further includes an auxiliary circuit board, which is disposed close to the second radiator and the bottom frame, and the first feed source and the second feed source are both disposed on the auxiliary circuit board.

13. The electronic device according to claim 10, characterized in that: The third frequency band and the fourth frequency band form a second continuous frequency band, and the second continuous frequency band covers the MHB frequency band.

14. The electronic device according to claim 13, characterized in that: The switch tuning circuit is used to tune the sub-band of the second continuous frequency band, and the sub-band of the second continuous frequency band is permanently resident in the Bluetooth frequency band when the sub-band of the second continuous frequency band is switched.

15. The electronic device according to claim 10, characterized in that: The second antenna unit also includes a second matching circuit, which includes a second capacitor, a third inductor, a fourth inductor, a fifth inductor and a third capacitor, one end of the second capacitor is electrically connected to the second feeding point, the other end of the second capacitor is electrically connected to one end of the third inductor, the other end of the third inductor is grounded, one end of the fourth inductor is electrically connected to the second feeding point, and the other end of the fourth inductor is grounded; the fifth inductor is electrically connected between the second feeding point and the second feed source, and the third capacitor is electrically connected between the second feeding point and the second feed source.

16. The electronic device according to claim 10, characterized in that: The switch tuning circuit comprises a switch unit, a plurality of first tuning branches and a plurality of second tuning branches; The switch unit includes a first end, at least one second end and at least one third end, the first end is grounded, and the switch unit is used to select any one or more of the at least one second end and the at least one third end to be connected to the first end; Each of the first tuning branches is electrically connected between the connection point and one of the second ends, and each of the second tuning branches is electrically connected between the connection end and one of the third ends.

17. The electronic device according to claim 16, characterized in that: The at least one second end includes a first sub-end, a second sub-end and a third sub-end, the plurality of first tuning branches include a first sub-branch, a second sub-branch, a third sub-branch and a fourth sub-branch, the first sub-branch is electrically connected to the connection point and the first sub-end, one end of the second sub-branch is electrically connected to an end of the first sub-branch away from the connection point, and the other end of the second sub-branch is grounded; The third sub-branch is electrically connected between the connection point and the second sub-end, and the fourth sub-branch is electrically connected between the connection point and the third sub-end; The number of the third ends is one, and the multiple second tuning branches include a fifth sub-branch, a sixth sub-branch, and a seventh sub-branch. The fifth sub-branch is electrically connected between the connection end and the third end, one end of the sixth sub-branch is electrically connected to an end of the fifth sub-branch away from the connection end, the other end of the sixth sub-branch is grounded, one end of the seventh sub-branch is electrically connected to the connection end, and the other end of the seventh sub-branch is grounded.

18. The electronic device according to claim 17, characterized in that: The first sub-branch, the second sub-branch, the third sub-branch, the fourth sub-branch, and the sixth sub-branch are all inductors, and the fifth sub-branch and the seventh sub-branch are all capacitors; When the switch unit is switched to the third end and the first end is turned on, the resonant current of the fifth resonant mode flows to the ground through the fifth sub-branch and the switch unit; When the switch unit is switched to the third end and disconnected from the first end, the resonant current of the fifth resonant mode flows to the ground via the seventh sub-branch.

19. The electronic device according to claim 17, wherein: The switch tuning circuit also includes at least one filter branch, one end of the at least one filter branch is electrically connected to at least one of the first tuning branches, the other end of the filter branch is electrically connected to the second end or is grounded, and the filter branch is used to conduct the resonant current of the MHB frequency band to ground.

20. The electronic device according to claim 19, characterized in that The at least one filter branch includes an eighth sub-branch, a ninth sub-branch and a tenth sub-branch, one end of the eighth sub-branch is electrically connected to one end of the first sub-branch, and the other end of the eighth sub-branch is electrically connected to the other end of the second sub-branch; one end of the ninth sub-branch is electrically connected to one end of the third sub-branch, and the other end of the ninth sub-branch is electrically connected to the second sub-end; one end of the tenth sub-branch is electrically connected to one end of the fourth sub-branch, and the other end of the tenth sub-branch is electrically connected to the third sub-end; the eighth sub-branch, the ninth sub-branch and the tenth sub-branch all include capacitors.

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