Electronic device

Abstract

The present application discloses an electronic device. The first antenna unit includes a first annular radiator, and the first annular radiator is disposed on the first side of the conductive middle frame. In the resonant mode, the first annular radiator excites a first current distribution and a second current distribution flowing in opposite directions on a pair of connecting sides of the conductive middle frame. The first current distribution flows from the first current weak point of the connecting side to the first side, and the second current distribution flows from the first current weak point to the second side. The second antenna unit includes a second annular radiator, and the second annular radiator is disposed on the second side of the conductive middle frame. In the resonant mode, the second annular radiator excites a third current distribution and a fourth current distribution flowing in opposite directions on a pair of connecting sides. The third current distribution flows from the second current weak point of the connecting side to the second side, and the fourth current distribution flows from the second current weak point to the first side. The electronic device provided by the present application can effectively improve the isolation degree between multiple antennas.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and particularly to an electronic device. Background Art

[0002] With the miniaturization of electronic devices and the pursuit of high-speed data transmission for Internet access, the number of antennas on electronic devices has increased. How to conduct structural design and layout design among multiple antennas to improve the isolation between multiple antennas, and thus improve the antenna performance of a multi-antenna system has become a key point for research. Summary of the Invention

[0003] Embodiments of this application provide an electronic device that can effectively improve the isolation between multiple antennas, and thus improve the antenna performance of a multi-antenna system.

[0004] In a first aspect, an electronic device provided by an embodiment of this application includes:

[0005] A conductive middle frame, including a first side and a second side that are oppositely arranged, and a pair of connecting sides connected between the first side and the second side;

[0006] A first antenna unit, where the first antenna unit includes a first annular radiator. The first annular radiator is disposed on the first side and electrically connected to the conductive middle frame. In a resonant mode, the first annular radiator excites a first current distribution and a second current distribution flowing in opposite directions on a pair of the connecting sides. The first current distribution flows from a first current weak point on the connecting side to the first side, and the second current distribution flows from the first current weak point to the second side; and

[0007] A second antenna unit, where the second antenna unit includes a second annular radiator. The second annular radiator is disposed on the second side and electrically connected to the conductive middle frame. In a resonant mode, the second annular radiator excites a third current distribution and a fourth current distribution flowing in opposite directions on a pair of the connecting sides. The third current distribution flows from a second current weak point on the connecting side to the second side, and the fourth current distribution flows from the second current weak point to the first side.

[0008] In a second aspect, an electronic device provided by an embodiment of this application includes:

[0009] A conductive middle frame, including a first side and a second side that are oppositely arranged; and

[0010] A plurality of antenna units, including a first antenna unit and a second antenna unit, the first antenna unit and the second antenna unit are respectively disposed on the first side and the second side, and the main radiation direction of the first antenna unit in the far field region is opposite to the main radiation direction of the second antenna unit in the far field region; wherein, the main radiation direction of the first antenna unit in the far field region is the direction pointed by the main radiation beam of the radiation field formed by exciting the region of the conductive middle frame near the second side by the first antenna unit, and the main radiation direction of the second antenna unit in the far field region is the direction pointed by the main radiation beam of the radiation field formed by exciting the region of the conductive middle frame near the first side.

[0011] The electronic device provided by the present application, by respectively disposing a first antenna unit and a second antenna unit on opposite sides of the conductive middle frame, and enabling the first antenna unit to excite a first current distribution and a second current distribution with opposite current flows between the opposite sides of the conductive middle frame during resonance, and enabling the second antenna unit to excite a third current distribution and a fourth current distribution with opposite current flows between the opposite sides of the conductive middle frame during resonance, the far-field main radiation direction of the first antenna unit tends to the direction where the second current distribution lags, and the far-field main radiation direction of the second antenna unit tends to the direction where the fourth current distribution lags. Since the current flow direction of the second current distribution is different from the current flow direction of the fourth current distribution, the far-field main radiation direction of the first antenna unit is different from the far-field main radiation direction of the second antenna unit, indicating that the energy distribution regions of the first antenna unit and the second antenna unit are different and the overlap degree is small, thereby improving the spatial independence of the first antenna unit and the second antenna unit, increasing the isolation degree of the first antenna unit and the second antenna unit, reducing the envelope correlation coefficient between the two, and improving the antenna performance of the multi-antenna unit. Description of the Drawings

[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0013] Figure 1 is a schematic structural diagram of an electronic device provided by an embodiment of the present application;

[0014] Figure 2 is Figure 1 the exploded structural diagram of the provided electronic device;

[0015] Figure 3 is a top view of an antenna assembly provided by the present application;

[0016] Figure 4It is the current distribution diagram of the first antenna unit in the first antenna assembly provided by this application;

[0017] Figure 5 It is the current distribution diagram of the second antenna unit in the antenna assembly provided by this application;

[0018] Figure 6 It is Figure 4 The structural schematic diagram and current distribution diagram of the first antenna unit shown;

[0019] Figure 7 It is Figure 6 The structural schematic diagram of the first matching circuit shown;

[0020] Figure 8 It is Figure 6 The enlarged structural diagram and current distribution diagram of the first antenna unit shown;

[0021] Figure 9 It is Figure 6 The far-field pattern of the first antenna unit provided;

[0022] Figure 10 It is Figure 6 The far-field plan view of the first antenna unit provided;

[0023] Figure 11 It is Figure 4 The structural schematic diagram and current distribution diagram of the second antenna unit shown;

[0024] Figure 12 It is Figure 11 The far-field pattern of the first antenna unit in the antenna assembly shown;

[0025] Figure 13 It is Figure 11 The far-field pattern of the second antenna unit in the antenna assembly shown;

[0026] Figure 14 It is Figure 11 The far-field plan view of the first antenna unit and the second antenna unit in the antenna assembly shown;

[0027] Figure 15 It is Figure 11 The ECC result diagram of the antenna assembly of the first antenna unit and the second antenna unit in the antenna assembly shown;

[0028] Figure 16 It is the top view of the second antenna assembly provided by this application;

[0029] Figure 17 It is Figure 16 The current distribution diagram of the third antenna unit in the antenna assembly shown;

[0030] Figure 18 is Figure 16 the far - field pattern of the third antenna unit in the antenna assembly shown;

[0031] Figure 19 is Figure 16 the planar pattern of the third antenna unit in the antenna assembly shown;

[0032] Figure 20 is Figure 16 the ECC result graph between the third antenna unit and the first antenna unit in the antenna assembly shown;

[0033] Figure 21 is the top view of the third antenna assembly provided by this application;

[0034] Figure 22 is Figure 21 the current distribution graph of the fourth antenna unit in the antenna assembly shown;

[0035] Figure 23 is Figure 21 the far - field pattern of the fourth antenna unit in the antenna assembly shown;

[0036] Figure 24 is Figure 21 the planar pattern of the fourth antenna unit in the antenna assembly shown;

[0037] Figure 25 is Figure 21 the ECC curve graph between the first antenna unit and the fourth antenna unit in the antenna assembly shown;

[0038] Figure 26 is Figure 21 the ECC curve graph between the third antenna unit and the fourth antenna unit in the antenna assembly shown.

[0039] Explanation of the reference numerals in the figures:

[0040] Electronic device 1000;

[0041] Antenna assembly 100; Display screen 200; Housing 300; Frame 310; Rear cover 320; Conductive middle frame 400; First side 401; Second side 402; Third side 403; Fourth side 404;

[0042] Antenna unit 10a; First antenna unit 10; Second antenna unit 20; Third antenna unit 30; Fourth antenna unit 40;

[0043] First current distribution Q1; Second current distribution Q; Third current distribution Q3; Fourth current distribution Q4; Fifth current distribution Q5; Sixth current distribution Q6; Seventh current distribution Q7; First region D1; Second region D2; Third region D3; Fourth region D4;

[0044] The first current intensity point A1; the second current intensity point A2; the third current intensity point A3; the fourth current intensity point A4; the fifth current intensity point A5; the sixth current intensity point A6; the seventh current intensity point A7; the eighth current intensity point A8; the ninth current intensity point A9;

[0045] The first current weakness point B1; the second current weakness point B2; the third current weakness point B3; the fourth current weakness point B4; the fifth current weakness point B5; the sixth current weakness point B6;

[0046] The first annular radiator 11; the first matching circuit M1; the first feeder 12; the first connection end 111; the second connection end 112; the changeover switch K1; a plurality of adjustment circuits T1; the first extension section 113; the second extension section 114; and the third extension section 115; the first connection segment 116; the second connection segment 117; the second annular radiator 21; the second matching circuit M2; the second feeder 22; the third connection end 211; the fourth connection end 212; the third annular radiator 31; the third matching circuit M3; the third feeder 32; the fifth connection end 311; the sixth connection end 312; the inverted-F radiator 41; the fourth matching circuit M4; the fourth feeder 42. Detailed implementation manners

[0047] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. In addition, the mention of "embodiment" or "implementation manner" in the present application means that a specific feature, structure or characteristic described in conjunction with the embodiment or implementation manner can be included in at least one embodiment of the present application. The appearance of this phrase in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described in the present application can be combined with other embodiments.

[0048] As the requirement for the Internet access speed of electronic devices increases, the requirement for the throughput of data transmission increases. The Multiple Input Multiple Output (MIMO) system has great advantages in improving the data rate. This system uses multiple transmit antennas and multiple receive antennas at the transmitting end and receiving end of a wireless communication system respectively, enabling signals to be transmitted and received through multiple antennas at the transmitting and receiving ends, creating multiple parallel spatial channels, and multiple information streams or multiple channels to be transmitted simultaneously in the same frequency band, thereby increasing the system capacity. The MIMO system can make full use of spatial resources, achieve multiple-input and multiple-output through multiple antennas, increase the spatial dimension by using multiple antennas without increasing the spectrum resources and antenna transmission power, realize multi-dimensional signal processing, obtain spatial diversity gain or spatial multiplexing gain, and can double the system channel capacity.

[0049] Since the MIMO system improves the signal capacity by transmitting parallel spatially independent data streams, the MIMO system requires low mutual coupling performance between antennas. The Envelope correlation coefficient (ECC) is a quantitative index reflecting the spatial correlation between antennas and can be used to evaluate the independence of antennas in terms of radiation pattern and polarization in the MIMO system. The smaller the envelope correlation coefficient, the smaller the correlation between antennas, the higher the diversity gain of the MIMO system, and the better the communication performance of the MIMO system.

[0050] To obtain better communication performance of the MIMO system, the MIMO system requires the spacing between antennas to be above half a wavelength. When the MIMO system is applied to low-frequency antennas, the MIMO system has certain requirements for the spacing between low-frequency antennas. However, with the miniaturization development of electronic devices, the space on electronic devices is extremely limited. How to improve the poor correlation between antennas in the MIMO system on electronic devices, effectively increase the isolation between multiple antennas, and then improve the antenna performance of the multi-antenna system urgently needs to be solved.

[0051] Please refer to Figure 1 , Figure 1Schematic diagram of the structure of an electronic device 1000 provided by an embodiment of the present application. The electronic device 1000 in the embodiments of the present application may be a mobile phone, a tablet computer, a desktop computer, a laptop computer, an e-reader, a handheld computer, an electronic display screen, a notebook computer, an ultra-mobile personal computer (UMPC), a netbook, as well as cellular phones, personal digital assistants (PDAs), augmented reality (AR) / virtual reality (VR) devices, media players, smart wearable devices and other electronic products.

[0052] Please refer to Figure 2 , the electronic device 1000 includes a conductive middle frame 400 and an antenna assembly 100.

[0053] The present application does not limit the specific shape of the conductive middle frame 400. The conductive middle frame 400 includes a first side 401 and a second side 402 which are oppositely arranged. Optionally, the conductive middle frame 400 may be generally rectangular. Of course, in other embodiments, the conductive middle frame 400 may also be trapezoidal, rhombic or other shapes, etc.

[0054] Optionally, please refer to Figure 2 , taking the electronic device 1000 as a mobile phone as an example to illustrate the inventive concept of the present application. The electronic device 1000 further includes a display screen 200 and a housing 300. The conductive middle frame 400 described in the present application may be the middle frame of the electronic device 1000. The display screen 200 is disposed on the front side of the conductive middle frame 400 (the front side refers to the direction facing the user when the user normally uses the display screen 200), and the housing 300 includes a frame 310 and a rear cover 320. The display screen 200 and the rear cover 320 are respectively located on the front and rear sides of the conductive middle frame 400. Among them, the frame 310 is connected between the display screen 200 and the rear cover 320 and surrounds the conductive middle frame 400 on all sides. The display screen 200, the frame 310 and the rear cover 320 form a relatively closed whole-machine housing for the electronic device 1000. Of course, in other embodiments, a display screen 200 may also be provided on the rear side of the electronic device 1000.

[0055] Among them, the frame 310 and the rear cover 320 can be an integrated structure or a split structure. When the frame 310 and the rear cover 320 are of a split structure, the frame 310 can form an integrated structure with the middle frame (the conductive middle frame 400). A plurality of mounting grooves for mounting various electronic devices are formed on the middle frame. After the display screen 200, the middle frame, and the rear cover 320 are covered, receiving spaces are formed on both sides of the middle frame. The electronic device 1000 further includes components such as a circuit board (including a main board, a secondary board, a flexible circuit board, etc.), a battery, a camera module, a microphone, a receiver, a speaker, a face recognition module, a fingerprint recognition module, etc. that are disposed in the receiving spaces and can implement the basic functions of a mobile phone, which will not be elaborated in this embodiment. It can be understood that the above introduction to the electronic device 1000 is only an illustration of an environment in which the antenna assembly 100 is applied, and the specific structure of the electronic device 1000 should not be construed as a limitation on the antenna assembly 100 provided in this application.

[0056] Please refer to Figure 3 , in this embodiment, the conductive middle frame 400 is taken as an example of being generally rectangular for illustration. The conductive middle frame 400 includes the first side 401 and the second side 402 that are oppositely arranged, and a pair of connecting sides connected between the first side 401 and the second side 402. Among them, the connecting sides include the third side 403 and the fourth side 404 that are oppositely arranged. Among them, the first side 401 and the second side 402 are two short sides of the conductive middle frame 400. The third side 403 and the fourth side 404 are two long sides of the conductive middle frame 400. It can be understood that the conductive middle frame 400 has conductivity.

[0057] For the convenience of subsequent reference and description, define the direction in which the first side 401 and the second side 402 of the conductive middle frame 400 are arranged as the Y-axis direction. Among them, the direction in which the second side 402 points to the first side 401 is the positive Y-axis direction, and the direction in which the first side 401 points to the second side 402 is the negative Y-axis direction. Define the direction in which the third side 403 and the fourth side 404 of the conductive middle frame 400 are arranged as the X-axis direction. Among them, the direction in which the fourth side 404 points to the third side 403 is the positive X-axis direction, and the direction in which the third side 403 points to the fourth side 404 is the negative X-axis direction. The thickness direction of the conductive middle frame 400 is the Z-axis direction, the direction in which the rear cover 320 points to the display screen 200 is the positive Z-axis direction, and the direction in which the display screen 200 points to the rear cover 320 is the negative Z-axis direction.

[0058] Please refer to Figure 3, the antenna assembly 100 further includes a plurality of antenna units 10a. The present application does not limit the specific number of the antenna units 10a. Optionally, the plurality of antenna units 10a can form a MIMO system to improve spatial diversity gain or spatial multiplexing gain, which can multiply the system channel capacity, thereby increasing the throughput of data transmission and the Internet access speed of the electronic device 1000.

[0059] Optionally, please refer to Figure 4 , the plurality of antenna units 10a include a first antenna unit 10 and a second antenna unit 20. The first antenna unit 10 and the second antenna unit 20 are respectively disposed on the first side 401 and the second side 402. It can be understood that the first antenna unit 10 being disposed on the first side 401 includes, but is not limited to, a part of the first antenna unit 10 (such as a radiator) being disposed outside the first side 401 and connected to the first side 401, and another part of the first antenna unit 10 (such as a feed source and a matching circuit) can be carried on a part of the conductive middle frame 400 close to the first side 401. The second antenna unit 20 being disposed on the second side 402 can refer to the first antenna unit 10 being disposed on the first side 401, which will not be elaborated here.

[0060] The first antenna unit 10 is electrically connected to the conductive middle frame 400. The conductive middle frame 400 can serve as a reference ground system for the first antenna unit 10.

[0061] Please refer to Figure 4 , the first antenna unit 10 includes a first annular radiator 11. The first annular radiator 11 is disposed on the first side 401 and electrically connected to the conductive middle frame 400. The first annular radiator 11 at least excites a first current distribution Q1 and a second current distribution Q2 flowing in opposite directions on a pair of connecting sides of the conductive middle frame 400 in the resonant mode. The first annular radiator 11 at least excites a first current distribution Q1 and a second current distribution Q2 flowing in opposite directions on the third side 403 and the fourth side 404 of the conductive middle frame 400 in the resonant mode. Each first current distribution Q1 flows from a first current weak point B1 on the connecting side where it is located to the first side 401, and each second current distribution Q2 flows from the first current weak point B1 on the connecting side where it is located to the second side 402.

[0062] For example, the first current distribution Q1 is in the first region D1 of the conductive middle frame 400 close to the first side 401. The second current distribution Q2 is in the second region D2 of the first region D1 away from the first side 401, where the first region D1 and the second region D2 are arranged in the reverse direction of the Y-axis. The current flow direction of the second current distribution Q2 is opposite to that of the first current distribution Q1. For example, the current flow direction of the first current distribution Q1 is along the positive direction of the Y-axis, and the current flow direction of the second current distribution Q2 is along the reverse direction of the Y-axis. It can be understood that the second current distribution Q2 is the far-field current distribution of the first antenna unit 10.

[0063] The area where the main radiation direction of the antenna unit 10a is located can be characterized from the far-field pattern of the antenna unit 10a. The far-field pattern of the antenna unit 10a is mainly generated by the effective current in the far field on the conductive middle frame 400. Specifically, the area where the main radiation direction of the antenna unit 10a is located is biased towards the direction of the current phase lag of the second current distribution Q2. Among them, the current flow direction of the second current distribution Q2 is along the reverse direction of the Y-axis, and the direction of the current phase lag of the second current distribution Q2 is the reverse direction of the Y-axis. Therefore, the main radiation direction of the first antenna unit 10 is biased towards the reverse direction of the Y-axis. Or rather, the area where the main radiation direction of the first antenna unit 10 is located is biased towards the reverse direction of the Y-axis.

[0064] The second antenna unit 20 is electrically connected to the conductive middle frame 400. The conductive middle frame 400 can be used as the reference ground system of the second antenna unit 20.

[0065] Please refer to Figure 5 , the second antenna unit 20 includes a second loop radiator 21. The second loop radiator 21 is arranged on the second side 402 and is electrically connected to the conductive middle frame 400. The second loop radiator 21 excites the third current distribution Q3 and the fourth current distribution Q4 with opposite flow directions on a pair of the connecting sides in the resonance mode. The second loop radiator 21 excites the third current distribution Q3 and the fourth current distribution Q4 with opposite flow directions on the third side 403 and the fourth side 404 of the conductive middle frame 400 in the resonance mode. Each of the third current distributions Q3 flows from the second current weak point B2 on its corresponding connecting side to the second side 402, and each of the fourth current distributions Q4 flows from the second current weak point B2 on its corresponding connecting side to the first side 401.

[0066] For example, the third current distribution Q3 is in the third region D3 of the conductive middle frame 400 close to the second side 402. The fourth current distribution Q4 is in the fourth region D4 of the third region D3 facing away from the second side 402, where the third region D3 and the fourth region D4 are arranged in sequence along the positive Y-axis direction.

[0067] Specifically, in this application, the region on the conductive middle frame 400 where the third current distribution Q3 is located is defined as the third region D3, and the region on the conductive middle frame 400 where the fourth current distribution Q4 is located is defined as the fourth region D4.

[0068] This application does not specifically limit the degree of overlap between the first region D1 and the fourth region D4, nor does it specifically limit the degree of integration between the second region D2 and the third region D3.

[0069] Optionally, the first region D1 coincides with the fourth region D4, and the second region D2 coincides with the third region D3, that is, the boundary line between the first region D1 and the second region D2 is the same as the boundary line between the third region D3 and the fourth region D4. Further optionally, a part of the first region D1 is the fourth region D4, another part of the first region D1 is the third region D3, and the whole of the second region D2 is the third region D3, that is, the boundary line between the first region D1 and the second region D2 is located within the third region D3, and the boundary line between the third region D3 and the fourth region D4 is located within the first region D1. Further optionally, a part of the first region D1 is the fourth region D4, a part of the second region D2 is the fourth region D4, and another part of the second region D2 is the third region D3, that is, the boundary line between the first region D1 and the second region D2 is located within the fourth region D4, and the boundary line between the third region D3 and the fourth region D4 is located within the second region D2. Further optionally, the second region D2 and the fourth region D4 may partially coincide or completely coincide.

[0070] The current flow direction of the third current distribution Q3 is opposite to the current flow direction of the fourth current distribution Q4. For example, the current flow direction of the third current distribution Q3 is along the negative Y-axis direction, and the current flow direction of the fourth current distribution Q4 is along the positive Y-axis direction. It can be understood that the fourth current distribution Q4 is the far-field current distribution of the second antenna unit 20.

[0071] For example, the current flow direction of the fourth current distribution Q4 is along the positive Y-axis, and the current phase lag direction of the fourth current distribution Q4 is the positive Y-axis. Therefore, the main radiation direction of the second antenna unit 20 is biased towards the positive Y-axis; in other words, the region where the main radiation direction of the second antenna unit 20 is located is biased towards the positive Y-axis.

[0072] In this application, the flow direction of the fourth current distribution Q4 is different from that of the second current distribution Q2, where the flow direction of the fourth current distribution Q4 is opposite to or intersects with that of the second current distribution Q2. In other words, the current phase lag direction of the second current distribution Q2 is different from that of the fourth current distribution Q4. Therefore, the region where the main radiation direction of the first antenna unit 10 is located is different from the region where the main radiation direction of the second antenna unit 20 is located, that is, the energy distribution direction of the first antenna unit 10 is different from that of the second antenna unit 20, and the space resources occupied by the first antenna unit 10 are different from the space resources occupied by the second antenna unit 20. That is, the independence between the first antenna unit 10 and the second antenna unit 20 is good, the envelope correlation coefficient is small, and the MIMO system formed by the first antenna unit 10 and the second antenna unit 20 can make full use of space resources and improve the antenna performance of the MIMO system.

[0073] This application does not specifically limit the frequency bands supported by the multiple antenna units 10a. The signal type to which the frequency band belongs can be a 4G signal for cellular mobile communication or a 5G signal for cellular mobile communication. The specific frequency band can be the LB band (low frequency), the MHB band (medium-high frequency), the UHB band (ultra-high frequency), etc. Among them, the LB band refers to the frequency band below 1000 MHz (excluding 1000 MHz). The MHB band refers to the frequency band of 1000 MHz - 3000 MHz (including 1000 MHz, excluding 3000 MHz). The UHB band refers to the frequency band of 3000 MHz - 10000 MHz (including 3000 MHz). The signal type to which the frequency band belongs can also be a Wi-Fi signal, a GNSS signal, a Bluetooth signal, etc. The Wi-Fi frequency band includes, but is not limited to, at least one of Wi-Fi 2.4G, Wi-Fi 5G, Wi-Fi 6E, etc. GNSS stands for Global Navigation Satellite System, and its Chinese name is the Global Navigation Satellite System. GNSS includes the global Global Positioning System (GPS), Beidou, the Global Navigation Satellite System (GLONASS), the Galileo satellite navigation system (Galileo), and regional navigation systems, etc.

[0074] The electronic device 1000 provided by the present application respectively sets the first antenna unit 10 and the second antenna unit 20 on the opposite sides of the conductive middle frame 400, and enables the first antenna unit 10 to excite the first current distribution Q1 and the second current distribution Q2 with opposite current flows between the opposite sides of the conductive middle frame 400 during resonance, and enables the second annular radiator 21 of the second antenna unit 20 to excite the third current distribution Q3 and the fourth current distribution Q4 with opposite current flows between the opposite sides of the conductive middle frame 400 during resonance. The far-field main radiation direction of the first antenna unit 10 biases towards the direction where the second current distribution Q2 lags, and the far-field main radiation direction of the second antenna unit 20 biases towards the direction where the fourth current distribution Q4 lags. Since the current flow direction of the second current distribution Q2 is different from that of the fourth current distribution Q4, the region where the far-field main radiation direction of the first antenna unit 10 is located is different from the region where the far-field main radiation direction of the second antenna unit 20 is located, indicating that the energy distribution regions of the first antenna unit 10 and the second antenna unit 20 are different and the overlap degree is small. Furthermore, the spatial independence of the first antenna unit 10 and the second antenna unit 20 is improved, the isolation degree of the first antenna unit 10 and the second antenna unit 20 is increased, the envelope correlation coefficient between the two is reduced, and the antenna performance of multiple antenna units 10a is improved.

[0075] Optionally, the current flow direction of the second current distribution Q2 is opposite to that of the fourth current distribution Q4. For example, the current flow direction of the first current distribution Q1 is along the positive Y-axis, and the current flow direction of the second current distribution Q2 is along the negative Y-axis. The current flow direction of the third current distribution Q3 is along the negative Y-axis, and the current flow direction of the fourth current distribution Q4 is along the positive Y-axis. In this way, the current directions of the first antenna unit 10 and the second antenna unit 20 provided by the embodiment of the present application are opposite. At this time, the direction where the region where the main radiation direction of the first antenna unit 10 is located biases is opposite to the direction where the region where the main radiation direction of the second antenna unit 20 is located biases. In this way, the energy radiation direction of the first antenna unit 10 is different from the energy radiation direction of the second antenna unit 20, and the energy distribution of the first antenna unit 10 and the second antenna unit 20 in their respective energy radiation directions is small, that is, the overlap degree of the energy distribution regions of the first antenna unit 10 and the second antenna unit 20 is low, further improving the correlation coefficient of the first antenna unit 10 and the second antenna unit 20 and enhancing the antenna performance.

[0076] Optionally, please refer to Figure 4When the first annular radiator 11 of the first antenna unit 10 generates a resonance mode, the current distribution on the conductive middle frame 400 is at least as follows: along the first direction (the reverse direction of the Y axis), a first current strong point A1, a first current weak point B1, and a seventh current strong point A7 are sequentially formed (the second current strong point A2 to the fourth current strong point A4 will be described later). The first current distribution Q1 flows from the first current weak point B1 to the first current strong point A1, and the second current distribution Q2 flows from the first current weak point B1 to the seventh current strong point A7.

[0077] It should be noted that the current intensity of the current strong point described in this application is greater than that of the current weak point. The current weak point described in this application includes, but is not limited to, a current zero point. And the intensity of each current weak point in this application is not limited, that is, the intensities of each current weak point can be the same or different. The intensity of each current strong point in this application is not limited, that is, the intensities of each current strong point can be the same or different.

[0078] This application is not limited to the first current strong point A1, the first current weak point B1, and the seventh current strong point A7 being collinearly arranged along the first direction. Optionally, the first current strong point A1, the first current weak point B1, and the seventh current strong point A7 can be arranged along the edge (connecting edge) of the conductive middle frame 400. Optionally, the position where the first annular radiator 11 of the first antenna unit 10 is electrically connected to the conductive middle frame 400 forms the first current strong point A1. For example, the first annular radiator 11 of the first antenna unit 10 is electrically connected to the first side 401 of the conductive middle frame 400, and the first current strong point A1 is arranged on the first side 401. The specific position where the first antenna unit 10 is connected to the first side 401 in this application is not limited. For example, the first antenna unit 10 is electrically connected to the midpoint position or near the midpoint position of the first side 401, and the first current strong point A1 is located at the midpoint position or near the midpoint position of the first side 401.

[0079] Optionally, the operating mode of the first antenna unit 10 between the second current weak point B2 and the first current strong point A1 is the 1 / 4 wavelength mode. In other words, the current distribution excited by the first annular radiator 11 of the first antenna unit 10 on the conductive middle frame 400 in the resonance mode is such that a first current strong point A1 is formed at the connection between the first annular radiator 11 of the first antenna unit 10 and the conductive middle frame 400, and after passing 1 / 4 wavelength (this wavelength is the dielectric wavelength corresponding to the frequency band supported by the first antenna unit 10) along the edge of the conductive middle frame 400, a first current weak point B1 is formed. Among them, the current direction is from the first current weak point B1 to the first current strong point A1. On the side of the first current weak point B1 facing away from the first current strong point A1, the current flow direction is reversed, and a seventh current strong point A7 is formed on the side of the first current weak point B1 facing away from the first current strong point A1. The above reverse current is from the first current weak point B1 to the seventh current strong point A7.

[0080] This application does not limit the intensity of the first current strong point A1 and the intensity of the seventh current strong point A7. Optionally, the intensity of the seventh current strong point A7 can be less than the intensity of the first current strong point A1, or can be equal to the intensity of the first current strong point A1. For example, when the distance between the seventh current strong point A7 and the first current weak point B1 is about 1 / 4 wavelength, the intensity of the seventh current strong point A7 can be close to the intensity of the first current strong point A1 or equal to the intensity of the seventh current strong point A7. When the distance between the seventh current strong point A7 and the first current weak point B1 is less than 1 / 4 wavelength, the intensity of the seventh current strong point A7 is less than the intensity of the first current strong point A1. It can be understood that the intensities of the first current strong point A1 and the seventh current strong point A7 are both greater than the intensity of the first current weak point B1.

[0081] Of course, in other embodiments, the operating mode of the first antenna unit 10 between the second current weak point B2 and the first current strong point A1 can also be the 1 / 2 wavelength mode, 3 / 4 wavelength mode, 1 times wavelength mode.

[0082] Optionally, please refer to Figure 4 , the first current strong point A1 is located on the first side 401. The current can flow to the first current strong point A1 from the clockwise direction or the counterclockwise direction. Therefore, in this embodiment, the number of the first current weak points B1 and the seventh current strong points A7 is two. The two first current weak points B1 are respectively located on both sides of the first current strong point A1. The two seventh current strong points A7 are respectively located on both sides of the first current strong point A1, so as to realize the current flowing along the edge of the conductive middle frame 400 from the clockwise direction or the counterclockwise direction to the first current strong point A1, forming a good current distribution.

[0083] Please refer to Figure 4, since the length of the first side 401 is short and the length of the first side 401 is less than 1 / 4 wavelength, one of the first current weak points B1 and one of the seventh current strong points A7 are located on the third side 403, and the other first current weak point B1 and the other seventh current strong point A7 are located on the fourth side 404.

[0084] When the first current strong point A1 is located at the central position of the first side 401, the two first current weak points B1 are symmetrically arranged in the Y-axis direction, and the two seventh current strong points A7 are symmetrically arranged in the Y-axis direction to form a good current distribution on the conductive middle frame 400 and form a better radiation pattern.

[0085] Optionally, please refer to Figure 6 , the first antenna unit 10 includes a first annular radiator 11, a first matching circuit M1 and a first feeder 12.

[0086] Among them, the first annular radiator 11 is the port for the first antenna unit 10 to receive and transmit radio frequency signals. Among them, the radio frequency signals are transmitted in the form of electromagnetic wave signals in the air medium. The present application does not specifically limit the shape of the first annular radiator 11, such as square, circular, etc. The form of the first annular radiator 11 includes but is not limited to strip, sheet, rod, coating, film, etc. Figure 3 The shown first annular radiator 11 is only an example and cannot limit the specific shape of the first annular radiator 11 provided by the present application. Optionally, the first annular radiator 11 can be integrated with the conductive frame, that is, the first annular radiator 11 is a frame antenna (or called a middle frame antenna). Further optionally, the antenna formed by the first annular radiator 11 is a bracket antenna. Among them, the bracket antenna includes but is not limited to a flexible circuit board antenna formed on a flexible printed circuit board (FPC), a laser direct structuring (LDS) antenna formed by laser direct structuring, a print direct structuring (PDS) antenna formed by printing directly, a conductive sheet antenna, etc.

[0087] Optionally, the material of the first annular radiator 11 is a conductive material, and the specific materials include but are not limited to metals such as copper, gold, and silver, or alloys formed by copper, gold, and silver with each other, or alloys formed by copper, gold, and silver with other materials; graphene, or conductive materials formed by combining graphene with other materials; oxide conductive materials such as indium tin oxide; hybrid materials formed by carbon nanotubes and polymers, etc.

[0088] Please refer to Figure 6, the first annular radiator 11 includes a first connection end 111 and a second connection end 112 that are close to each other. The first connection end 111 and the second connection end 112 are two ends of the first annular radiator 11. This application does not limit the distance between the first connection end 111 and the second connection end 112. Optionally, there is a relatively small spacing between the first connection end 111 and the second connection end 112. In this embodiment, the first annular radiator 11 is generally annular. In other words, the first annular radiator 11 is a loop antenna.

[0089] Please refer to Figure 6 , the first connection end 111 is electrically connected to the first side 401. Since the conductive middle frame 400 is a reference ground system, the first connection end 111 can also be referred to as a ground end.

[0090] Please refer to Figure 6 , the second connection end 112 is electrically connected to the first feed source 12 through the first matching circuit M1. The second connection end 112 can also be referred to as a first feeding point.

[0091] Please refer to Figure 6 , the first feed source 12 is electrically connected to the second connection end 112. Among them, the first feed source 12 includes but is not limited to a radio frequency transceiver chip and a radio frequency front-end circuit. The first feed source 12 is provided on the main board of the electronic device 1000. Among them, the main board of the electronic device 1000 is provided on the conductive middle frame 400.

[0092] The first matching circuit M1 is provided on the main board of the electronic device 1000. One end of the first matching circuit M1 is electrically connected to the second connection end 112, and the other end of the first matching circuit M1 is electrically connected to the first feed source 12. The first matching circuit M1 is used to tune the frequency band supported by the first annular radiator 11. The first matching circuit M1 includes but is not limited to capacitors, inductors, capacitor-inductor combinations, switch tuning devices, and so on.

[0093] The electrical connection manner in which the first matching circuit M1 is electrically connected to the second connection end 112 includes but is not limited to direct soldering, or indirect electrical connection through coaxial cables, microstrip lines, conductive shrapnel, conductive adhesives, etc. In this embodiment, the second connection end 112 is electrically connected to the first matching circuit M1 through a conductive member (such as conductive shrapnel).

[0094] The RF signal transmitted by the first feeder 12 is fed into the first annular radiator 11 through the second connection terminal 112. The RF signal can excite the first annular radiator 11 to generate a resonant current and form resonance to support the frequency band corresponding to the resonant current. Of course, the first feeder 12 can also receive the RF signal through the first annular radiator 11 via the second connection terminal 112. The first feeder 12 is used to excite the first annular radiator 11 to at least transmit and receive at least one of the LB band, MHB band, UHB band, Wi-Fi band, and GNSS band.

[0095] Please refer to Figure 6 , when the first annular radiator 11 of the first antenna unit 10 generates a resonant mode, a third current weak point B3 is formed between the first connection terminal 111 and the second connection terminal 112, a first current strong point A1 is formed at the first connection terminal 111, and a second current strong point A2 is formed at the second connection terminal 112.

[0096] Specifically, when the first annular radiator 11 of the first antenna unit 10 generates a resonant mode, the distribution of the resonant current on the first annular radiator 11 is as follows: current strong points are formed at both the first connection terminal 111 and the second connection terminal 112. Among them, the current strong point formed at the first connection terminal 111 is named the first current strong point A1, and the current strong point formed at the second connection terminal 112 is named the second current strong point A2. A current weak point is formed between the first connection terminal 111 and the second connection terminal 112, named the third current weak point B3. A part of the resonant current of the first annular radiator 11 of the first antenna unit 10 at resonance flows from the third current weak point B3 (e.g., in the clockwise direction) to the first current strong point A1 of the first connection terminal 111, and another part of the current (e.g., in the counterclockwise direction) of the first antenna unit 10 at resonance flows from the second current strong point A2 of the second connection terminal 112 to the third current weak point B3.

[0097] Optionally, the operating mode between the third current weak point B3 and the first current strong point A1 of the first antenna unit 10 is a 1 / 4 wavelength mode. The operating mode between the third current weak point B3 and the second current strong point A2 of the first antenna unit 10 is a 1 / 4 wavelength mode. Optionally, the third current weak point B3 is located at the middle position between the first connection terminal 111 and the second connection terminal 112 on the first annular radiator 11. Among them, the length of the first annular radiator 11 between the third current weak point B3 and the first current strong point A1 is about 1 / 4 wavelength (this wavelength is the dielectric wavelength corresponding to the frequency band supported by the first antenna unit 10), and the length of the first annular radiator 11 between the third current weak point B3 and the second current strong point A2 is about 1 / 4 wavelength (this wavelength is the dielectric wavelength corresponding to the frequency band supported by the first antenna unit 10).

[0098] Certainly, in other embodiments, the operating mode of the first antenna unit 10 between the third current weak point B3 and the first current strong point A1 may also be a 1 / 2 wavelength mode, a 3 / 4 wavelength mode, or a 1 wavelength mode. Correspondingly, the operating mode of the first antenna unit 10 between the third current weak point B3 and the second current strong point A2 may also be a 1 / 2 wavelength mode, a 3 / 4 wavelength mode, or a 1 wavelength mode.

[0099] Optionally, the first matching circuit M1 includes an inductor device. The inductance value of the inductor device is less than a preset inductance value. In other words, the first matching circuit M1 can perform small inductance feeding on the second connection end 112. Since the second connection end 112 is a current strong point, the impedance matching requirement for the second connection end 112 is relatively low. The first matching circuit M1 can be set to perform impedance matching on the second connection end 112 with a small inductor. Among them, the preset inductance value is not specifically limited, and the main consideration is to excite the frequency bands supported by actual requirements.

[0100] Alternatively, the first matching circuit M1 includes a 0-ohm resistor. The first matching circuit M1 is electrically connected to the second connection end 112 by setting a 0-ohm resistor. Since the second connection end 112 is a current strong point, the impedance matching requirement for the second connection end 112 is relatively low. The first matching circuit M1 can be set to perform impedance matching on the second connection end 112 with a 0-ohm resistor.

[0101] Optionally, please refer to Figure 7 , the first matching circuit M1 can be a switch switching circuit. Among them, the first matching circuit M1 includes at least one switching switch K1 and multiple adjustment circuits T1. The control end of the switching switch K1 is electrically connected to the controller. The selection end of at least one switching switch K1 can be selectively electrically connected to one of the multiple adjustment circuits T1. The other ends of the multiple adjustment circuits T1 are all grounded. The switching switch K1 is electrically connected to the controller, and the controller controls the selection end of the switching switch K1 to be selectively electrically connected to one of the multiple adjustment circuits T1. It can be understood that the impedance values of different adjustment circuits T1 are different. For example, the multiple adjustment circuits T1 are multiple capacitor devices with different capacitance values, or the multiple adjustment circuits T1 are multiple inductor devices with different inductance values. When the switching switch K1 is switched to be electrically connected to different adjustment circuits T1 under the action of the controller, the impedance value to the ground of the first matching circuit M1 is different, thereby adjusting the equivalent electrical length of the first matching circuit M1, further adjusting the sum of the equivalent electrical length of the first matching circuit M1 and the electrical length of the first annular radiator 11, and further tuning the frequency band size supported by the first annular radiator 11.

[0102] Optionally, the switching switch K1 can be a single-pole multi-throw switch. Further optionally, the number of the switching switches K1 is multiple. One end of each switching switch K1 is electrically connected to the first annular radiator 11, and the other ends of the multiple switching switches K1 are respectively electrically connected to multiple adjustment circuits T1. The multiple adjustment circuits T1 are selected by controlling the conduction and disconnection of the multiple switching switches K1.

[0103] Optionally, one of the adjustment circuits T1 can be a capacitor, an inductor, a series device of a capacitor and an inductor, a parallel device of a capacitor and an inductor, a parallel connection of the above series device and a capacitor, a parallel connection of the above series device and an inductor, a parallel connection of two of the above series devices, a series connection of two of the above parallel devices, and so on. Of course, in other embodiments, the first matching circuit M1 can include a tunable capacitor. Since the capacitance value of the tunable capacitor is adjustable, there is no need to additionally provide a first matching circuit M1 to switch and select different adjustment circuits T1. Of course, in other embodiments, at least one adjustment circuit T1 can be set as a tunable capacitor.

[0104] In this application, the first annular radiator 11 is not limited to being a rectangular ring, a circular ring, an oval ring, a diamond ring, etc. In this embodiment, the first annular radiator 11 is taken as an example of a rectangular ring for illustration.

[0105] Optionally, please refer to Figure 8 , the first annular radiator 11 further includes a first extension section 113, a second extension section 114 and a third extension section 115 connected in sequence. The second extension section 114 is disposed opposite to the first side 401. That is, the second extension section 114 extends along the X-axis direction. Further, the second extension section 114 can be disposed outside the first side 401 and parallel to the first side 401. The first extension section 113 and the third extension section 115 are both located between the second extension section 114 and the first side 401, and the first extension section 113 and the third extension section 115 are arranged in sequence along the extending direction of the first side 401. The first extension section 113 and the third extension section 115 are also parallel to the first side 401. The first extension section 113 and the third extension section 115 are collinear along the X-axis direction. Further, the first annular radiator 11 further includes a first connection section 116 connected between the first extension section 113 and the third extension section 115, wherein the first connection section 116 extends along the Y-axis direction. The first annular radiator 11 further includes a second connection section 117 connected between the second extension section 114 and the third extension section 115, wherein the second connection section 117 extends along the Y-axis direction.

[0106] The first connection end 111 is one end where the first extension section 113 is connected to the conductive middle frame 400, the second connection end 112 is one end where the third extension section 115 is connected to the first matching circuit M1, and the third current weak point B3 is located on the second extension section 114. Optionally, the first annular radiator 11 may have a structure symmetric about the Y-axis, that is, the first extension section 113 and the third extension section 115 have the same length, and the third current weak point B3 is located at the midpoint of the second extension section 114.

[0107] Please refer to Figure 6 and Figure 8 , Figure 8 When the first annular radiator 11 is a loop antenna, the current strong points, current weak points, and current distributions excited on the first annular radiator 11 and the conductive middle frame 400 are shown. The first antenna unit 10 forms a current weak point (i.e., the third current weak point B3) at the center position of the second extension section 114 of the first annular radiator 11, a current strong point (i.e., the first current strong point A1) at the center position of the first side 401 of the conductive middle frame 400, a current weak point (i.e., the first current weak point B1) and a current strong point (i.e., the seventh current strong point A7) are sequentially formed along the reverse Y-axis on the third side 403 of the conductive middle frame 400, a current weak point (i.e., the first current weak point B1) and a current strong point (i.e., the seventh current strong point A7) are sequentially formed along the reverse Y-axis on the fourth side 404 of the conductive middle frame 400, and a current weak point is formed at the center position of the second side 402 of the conductive middle frame 400. Among them, the current flow directions are all from the current weak points to the current strong points. The above forms the first current distribution Q1 and the second current distribution Q2.

[0108] Please refer to Figure 9 and Figure 10 , Figure 9 and Figure 10 are respectively Figure 6 the far-field pattern and the far-field plan view of the first antenna unit 10 provided. It can be seen from the far-field pattern that the far-field main radiation energy region of the first antenna unit 10 tends to the region where the second current distribution Q2 is located. It can be seen from the far-field plan view that the region to which the far-field main radiation direction of the first antenna unit 10 tends is biased towards the negative Y-axis direction. For example, referring to the part of the radiation boundary line exceeding the 0 equipotential line in the far-field plan view is below the X-axis and biased towards the negative Y-axis direction.

[0109] The above is an example description of the specific structure of the first antenna unit 10 and the current distribution formed by the first antenna unit 10 on the conductive middle frame 400. The following is an example description of the specific structure of the second antenna unit 20 and the current distribution formed by the second antenna unit 20 on the conductive middle frame 400.

[0110] Please refer to Figure 11 As shown in Figure 11 , when the second annular radiator 21 of the second antenna unit 20 is in resonance, third current intensity points A3, second current weak points B2, and eighth current intensity points A8 are sequentially formed along the reverse direction of the first direction on the connection side of the conductive middle frame 400. The third current distribution Q3 flows from the second current weak point B2 to the third current intensity point A3, and the fourth current distribution Q4 flows from the second current weak point B2 to the eighth current intensity point A8.

[0111] Among them, the second antenna unit 20 is disposed on the second side 402. The second antenna unit 20 is symmetric about the X-axis with the first antenna unit 10. The current intensity points, current weak points, and current distributions formed by the second annular radiator 21 of the second antenna unit 20 on the conductive middle frame 400 can also be symmetric about the X-axis with the current intensity points, current weak points, and current distributions formed by the first antenna unit 10 on the conductive middle frame 400.

[0112] Among them, the formation of the third current intensity point A3 can refer to the first current intensity point A1, the formation of the second current weak point B2 can refer to the first current weak point B1, and the formation of the eighth current intensity point A8 can refer to the seventh current intensity point A7.

[0113] Specifically, please refer to Figure 11 As shown in Figure 11 , the third current intensity point A3 is the connection point where the second annular radiator 21 of the second antenna unit 20 is electrically connected to the second side 402 of the conductive middle frame 400. Further, the third current intensity point A3 is located at the midpoint position of the second side 402. The number of the second current weak points B2 is two, and the two second current weak points B2 are respectively located on the third side 403 and the fourth side 404. The number of the eighth current intensity points A8 is two, and the two eighth current intensity points A8 are respectively located on the third side 403 and the fourth side 404.

[0114] The third current distribution Q3 flows from the second current weak point B2 to the third current intensity point A3. The fourth current distribution Q4 flows from the second current weak point B2 to the eighth current intensity point A8.

[0115] Optionally, the mode between the third current intensity point A3 and the second current weak point B2 is a 1 / 4 wavelength mode.

[0116] This application does not specifically limit the relative positions of the second current weak point B2 and the first current weak point B1. Optionally, the second current weak point B2 is located between the first current strong point A1 and the first current weak point B1; or, the positions of the second current weak point B2 and the first current weak point B1 coincide; or, the second current weak point B2 is located between the first current weak point B1 and the seventh current strong point A7; or, the second current weak point B2 is located between the seventh current strong point A7 and the second side 402.

[0117] This application does not specifically limit the length of the third side 403. In theory, the longer the length of the third side 403, the better. However, since the third side 403 is the long side of the conductive middle frame 400 of the electronic device 1000, it needs to be compatible with the overall length design of the electronic device 1000 and the supported frequency bands. This application designs the length of the third side 403. To ensure that the first antenna unit 10 can excite more of the second current distribution Q2 on the conductive middle frame 400, the distance between the seventh current strong point A7 and the first side 401 is at least about 1 / 2 wavelength (where the distance from the first current strong point A1 to the first current weak point B1 is about 1 / 4 wavelength, and the distance from the first current weak point B1 to the seventh current strong point A7 is about 1 / 4 wavelength); to ensure that the second antenna unit 20 can excite more of the fourth current distribution Q4 on the conductive middle frame 400, the distance between the eighth current strong point A8 and the second side 402 is at least about 1 / 2 wavelength (where the distance from the third current strong point A3 to the second current weak point B2 is about 1 / 4 wavelength, and the distance from the second current weak point B2 to the eighth current strong point A8 is about 1 / 4 wavelength). In other words, the distance between the first side 401 and the second side 402 is at least about 1 / 2 wavelength.

[0118] Optionally, the length of the third side 403 (i.e., the distance between the first side 401 and the second side 402) is greater than or equal to 0.45λ. Wherein, λ is the dielectric wavelength corresponding to the frequency band supported by the first antenna unit 10. The above distance makes the length of the third side 403 relatively suitable, the length of the electronic device 1000 will not be too long, and the envelope correlation coefficient between the first antenna unit 10 and the second antenna unit 20 is relatively low.

[0119] The following uses the accompanying drawings to give an example of the specific structure of the second antenna unit 20.

[0120] Please refer to Figure 11 , the second antenna unit 20 includes a second loop radiator 21, a second matching circuit M2, and a second feeder 22.

[0121] Among them, the specific description of the second annular radiator 21 can refer to that of the first annular radiator 11. The specific description of the second matching circuit M2 can refer to that of the second annular radiator 21. The specific description of the second feed 22 can refer to that of the first feed 12.

[0122] Optionally, the shape of the first annular radiator 11 can be the same as that of the second annular radiator 21, that is, the second annular radiator 21 is also an annular antenna. Further, the second annular radiator 21 is a rectangular loop antenna.

[0123] Among them, please refer to Figure 11 , the second annular radiator 21 includes a third connection end 211 and a fourth connection end 212 that are close to each other. The third connection end 211 is electrically connected to the second side 402. The fourth connection end 212 is electrically connected to the second feed 22 through the second matching circuit M2. Among them, the specific connection manner between the second annular radiator 21, the second matching circuit M2 and the second feed 22 can refer to the specific connection manner between the first annular radiator 11, the first matching circuit M1 and the first feed 12.

[0124] Please refer to Figure 11 , when the second annular radiator 21 of the second antenna unit 20 is in resonance, a fourth current weak point B4 is formed between the third connection end 211 and the fourth connection end 212, a third current strong point A3 is formed at the third connection end 211, and a fourth current strong point A4 is formed at the second connection end 112. In this embodiment, the formation of the fourth current weak point B4 can refer to the formation of the third current weak point B3.

[0125] Please refer to Figure 11 , when the second annular radiator 21 of the second antenna unit 20 is in resonance, a part of the current flows from the third current strong point A3 at the third connection end 211 to the fourth current weak point B4. When the second annular radiator 21 of the second antenna unit 20 is in resonance, another part of the current flows from the fourth current strong point A4 at the fourth connection end 212 to the fourth current weak point B4.

[0126] Optionally, the second antenna unit 20 can work simultaneously with the first antenna unit 10 and support the same frequency band to form a MIMO antenna system.

[0127] Optionally, the operating mode of the second antenna unit 20 between the fourth current weak point B4 and the third current strong point A3 is the 1 / 4 wavelength mode. The operating mode of the second antenna unit 20 between the fourth current weak point B4 and the fourth current strong point A4 is the 1 / 4 wavelength mode.

[0128] Of course, in other embodiments, the operating mode of the second antenna unit 20 between the fourth current weak point B4 and the third current strong point A3 may also be a 1 / 2 wavelength mode, a 3 / 4 wavelength mode, or a 1-fold wavelength mode. Correspondingly, the operating mode of the second antenna unit 20 between the fourth current weak point B4 and the fourth current strong point A4 may also be a 1 / 2 wavelength mode, a 3 / 4 wavelength mode, or a 1-fold wavelength mode.

[0129] Optionally, please refer to Figure 11 , the third current strong point A3 is located at or near the midpoint of the second side 402. Thus, the number of the second current weak points B2 is two, and the two second current weak points B2 are symmetrically arranged on the third side 403 and the fourth side 404 respectively. The number of the eighth current strong points A8 is two, and the two eighth current strong points A8 are symmetrically arranged on the third side 403 and the fourth side 404 respectively.

[0130] Optionally, the second matching circuit M2 can feed the fourth connection end 212 through a small inductor or a 0-ohm resistor. The second matching circuit M2 can also be a switch switching circuit, and specific descriptions can refer to the specific description in the first matching circuit M1.

[0131] The envelope correlation coefficient reflects the cross-correlation of the received complex radiation patterns of the main and auxiliary antennas in three-dimensional space. In receive diversity and MIMO reception, it is generally desired that the radiation performances of the main and auxiliary antennas can complement each other, and the radiation patterns of the two antennas have relatively large differences. There is no similarity between the radiation patterns of the main and auxiliary antennas, and at this time, the reception can achieve the best ideal effect. Based on the two factors of the polarization orthogonality principle of the far-field pattern of the antenna unit 10a and the different main radiation directions, this application obtains good ECC characteristics between them.

[0132] Based on the foregoing first antenna unit 10 and second antenna unit 20 that are annular antennas disposed on the conductive middle frame 400, the far-field patterns formed by exciting the first current distribution Q1, the second current distribution Q2, the third current distribution Q3, and the fourth current distribution Q4 on the conductive middle frame 400 are as follows.

[0133] Please refer to Figure 12 and Figure 13 , Figure 12 is Figure 11 the far-field pattern of the first antenna unit 10 in the antenna assembly 100 shown in Figure 13 is Figure 11 the far-field pattern of the second antenna unit 20 in the antenna assembly 100 shown in Figure 12 It can be seen that the main radiation direction region (the darker part) of the far-field pattern of the first antenna unit 10 tends to be in the reverse direction of the Y axis. FromFigure 13 It can be seen that the main radiation direction area (the darker part) of the far-field pattern of the second antenna unit 20 is biased towards the positive Y-axis.

[0134] Figure 14 is the far-field plan view of the first antenna unit 10 and the second antenna unit 20. Figure 14 The dashed part in it is the far-field plan view of the first antenna unit 10. From Figure 14 the dashed part indicated by the arrow in it is the area where the main radiation direction of the first antenna unit 10 is located. Figure 14 The solid part in it is the far-field plan view of the second antenna unit 20. Figure 14 the solid part indicated by the arrow in it is the area where the main radiation direction of the second antenna unit 20 is located. From Figure 14 it can be seen that the dashed part indicated by the arrow is biased towards the negative Y-axis, and the solid part indicated by the arrow is biased towards the positive Y-axis, that is, the area where the main radiation direction of the first antenna unit 10 is located is different (for example, opposite) from the area where the main radiation direction of the second antenna unit 20 is located, and the energy distribution of the first antenna unit 10 in the main radiation direction of the second antenna unit 20 is small, and the energy distribution of the second antenna unit 20 in the main radiation direction of the first antenna unit 10 is small, that is, the energy distribution of the first antenna unit 10 and the second antenna unit 20 in their respective main radiation directions is small, and the patterns of the first antenna unit 10 and the second antenna unit 20 are complementary, having good spatial independence.

[0135] Figure 15 is Figure 11 the ECC result diagram of the antenna assembly of the first antenna unit 10 and the second antenna unit 20 in the antenna assembly 100 shown. Taking 0.72 GHz - 0.78 GHz (for example, operating in the N28 band) as an example, from Figure 15 it can be seen that the ECC between the first antenna unit 10 and the second antenna unit 20 is less than 0.41, meeting the requirements of general operators (for example, less than 0.5).

[0136] Optionally, please refer to Figure 16 and Figure 17 The plurality of antenna units 10a further includes a third antenna unit 30. The third antenna unit 30 includes a third annular radiator 31. The third annular radiator 31 is disposed on the third side 403 and electrically connected to the conductive middle frame 400. When the third annular radiator 31 is in resonance, at least a fifth current distribution Q5 and a sixth current distribution Q6 flowing in opposite directions are excited on the third side 403, and the flowing direction of the sixth current distribution Q6 is opposite to the flowing direction of the fifth current distribution Q5.

[0137] Please refer to Figure 17When the third antenna unit 30 generates a resonant mode, at least the following current distributions are formed on the third side 403: a fifth current strong point A5, a fifth current weak point B5, and a ninth current strong point A9 are formed on the third side 403. The fifth current distribution Q5 flows from the fifth current weak point B5 to the fifth current strong point A5, and the sixth current distribution Q6 flows from the fifth current weak point B5 to the ninth current strong point A9.

[0138] Optionally, the structure of the third antenna unit 30 may be the same as that of the first antenna unit 10. The formation of the fifth current strong point A5 can refer to the first current strong point A1. The formation of the fifth current weak point B5 can refer to the formation of the first current weak point B1. The formation of the ninth current strong point A9 can refer to the formation of the fifth current strong point A5.

[0139] Among them, the current distribution of the third antenna unit 30 is equivalent to rotating the current distribution of the first antenna unit 10 counterclockwise by 90°. Of course, since the length of the third side 403 is greater than 1 / 4 wavelength, both the fifth current weak point B5 and the ninth current strong point A9 are located on the third side 403.

[0140] Optionally, please refer to Figure 17 When the current can flow to the fifth current strong point A5 in the clockwise or counterclockwise direction, the number of the fifth current weak points B5 is two, and the two fifth current weak points B5 are respectively arranged on the upper and lower sides of the fifth current strong point A5. The number of the ninth current strong points A9 is two, and the two ninth current strong points A9 are respectively arranged on the upper and lower sides of the fifth current strong point A5.

[0141] Optionally, the fifth current strong point A5 can be located at or near the midpoint of the third side 403.

[0142] Optionally, the mode between the fifth current strong point A5 and the fifth current weak point B5 is 1 / 4 wavelength.

[0143] The following takes the accompanying drawings as an example to illustrate the specific structure of the third antenna unit 30.

[0144] Please refer to Figure 17 The third antenna unit 30 includes a third loop radiator 31, a third matching circuit M3, and a third feed 32.

[0145] Among them, the third loop radiator 31 can refer to the specific description of the first loop radiator 11. The third matching circuit M3 can refer to the specific description of the second loop radiator 21. The third feed 32 can refer to the specific description of the first feed 12.

[0146] Optionally, the shape of the first annular radiator 11 may be the same as that of the third annular radiator 31, that is, the third annular radiator 31 is also an annular antenna. Further, the third annular radiator 31 is a rectangular loop antenna.

[0147] Please refer to Figure 17 , the third annular radiator 31 includes a fifth connection end 311 and a sixth connection end 312 that are close to each other. The fifth connection end 311 is electrically connected to the third side 403. The sixth connection end 312 is electrically connected to the third feed 32 through the third matching circuit M3. Among them, the specific connection manner among the third annular radiator 31, the third matching circuit M3, and the third feed 32 can refer to the specific connection manner among the first annular radiator 11, the first matching circuit M1, and the first feed 12.

[0148] When the third antenna unit 30 is in resonance, a sixth current weak point B6 is formed between the fifth connection end 311 and the sixth connection end 312, a fifth current strong point A5 is formed at the fifth connection end 311, and a sixth current strong point A6 is formed at the sixth connection end 312. In this embodiment, the formation of the sixth current weak point B6 can refer to the formation of the third current weak point B3.

[0149] Please refer to Figure 17 , when the third antenna unit 30 is in resonance, a part of the current flows from the fifth current strong point A5 of the fifth connection end 311 to the sixth current weak point B6. Another part of the current of the third antenna unit 30 when in resonance flows from the sixth current strong point A6 of the sixth connection end 312 to the sixth current weak point B6.

[0150] Optionally, the third antenna unit 30 can work simultaneously with the first antenna unit 10 and the second antenna unit 20 and support the same frequency band to form a MIMO antenna system.

[0151] Optionally, the operating mode of the third antenna unit 30 between the sixth current weak point B6 and the fifth current strong point A5 is a 1 / 4 wavelength mode. The operating mode of the third antenna unit 30 between the sixth current weak point B6 and the sixth current strong point A6 is a 1 / 4 wavelength mode.

[0152] Of course, in other embodiments, the operating mode of the third antenna unit 30 between the sixth current weak point B6 and the fifth current strong point A5 can also be a 1 / 2 wavelength mode, a 3 / 4 wavelength mode, or a 1-fold wavelength mode. Correspondingly, the operating mode of the third antenna unit 30 between the sixth current weak point B6 and the sixth current strong point A6 can also be a 1 / 2 wavelength mode, a 3 / 4 wavelength mode, or a 1-fold wavelength mode.

[0153] Figure 18 and Figure 19 are respectively the far - field pattern and the planar pattern of the third antenna unit 30. From Figure 18 it can be seen that the direction of the electric - field zero point of the third antenna unit 30 is along the X - axis direction, that is, the electric - field polarization direction in the far - field region is along the X - axis direction.

[0154] And from Figure 9 it can be seen that the direction of the electric - field zero point of the first antenna unit 10 is the Y - axis direction, that is, the electric - field polarization direction in the far - field region is along the Y - axis direction. From Figure 13 it can be seen that the direction of the electric - field zero point of the second antenna unit 20 is along the Y - axis direction, that is, the electric - field polarization direction in the far - field region is along the Y - axis direction. Obviously, the electric - field polarization direction of the third antenna unit 30 in the far - field region is orthogonal to the electric - field polarization direction of the second antenna unit 20 in the far - field region, and the electric - field polarization direction of the third antenna unit 30 in the far - field region is orthogonal to the electric - field polarization direction of the first antenna unit 10 in the far - field region, so as to achieve a lower envelope correlation coefficient between two adjacent antenna units 10a, thereby improving the communication performance of the MIMO system.

[0155] In addition, from Figure 14 it can be seen that the main - radiation - direction region of the first antenna unit 10 tends to be in the reverse Y - axis direction, and the main - radiation - direction region of the second antenna unit 20 tends to be in the positive Y - axis direction.

[0156] From Figure 19 it can be seen that the main - radiation - direction region of the third antenna unit 30 is along the positive Y - axis direction and the reverse Y - axis direction, as shown in Figure 19 the positions pointed by the arrows. Among them, the main - radiation - direction region of the third antenna unit 30 is different from the main - radiation - direction regions of the first antenna unit 10 and the second antenna unit 20. The energy distribution of the first antenna unit 10, the second antenna unit 20, and the third antenna unit 30 in their respective main - radiation directions is small. The first antenna unit 10, the second antenna unit 20, and the third antenna unit 30 have good spatial independence, which is also conducive to forming a lower envelope correlation coefficient, thereby improving the communication performance of the MIMO system.

[0157] Figure 20 is the ECC result diagram between the third antenna unit 30 and the first antenna unit 10. Taking 0.72 GHz - 0.78 GHz (for example, operating in the N28 band) as an example, it can be seen from the figure that the ECC between the third antenna unit 30 and the first antenna unit 10 is less than 0.33, meeting the requirements of general operators (for example, less than 0.5).

[0158] Please refer to Figure 21 , the multiple antenna units 10a further include a fourth antenna unit 40. The fourth antenna unit 40 is disposed on the fourth side 404.

[0159] Please refer to Figure 22 wherein the fourth antenna unit 40 includes an inverted-F radiator 41 disposed on the fourth side 404 and electrically connected to the conductive middle frame 400. The inverted-F radiator 41 forms at least a seventh current distribution Q7 on the fourth side 404 at resonance. The flow direction of the seventh current distribution Q7 intersects with the flow directions of the second current distribution Q2, the fourth current distribution Q4, and the fifth current distribution Q5. For example, the flow direction of the seventh current distribution Q7 is obliquely upward or obliquely downward to the left.

[0160] Optionally, the first antenna unit 10 to the fourth antenna unit 40 simultaneously support the same frequency band to form a 4*4 MIMO system.

[0161] Please refer to Figure 21 wherein the fourth antenna unit 40 includes an inverted-F radiator 41, a fourth matching circuit M4, and a fourth feeder 42. The present application is not limited to the shape of the inverted-F radiator 41.

[0162] Please refer to Figure 22 wherein the inverted-F radiator 41 includes a seventh connection end 411, a feeding point 412, and a free end 413 arranged in sequence. The seventh connection end 411 is electrically connected to the fourth side 404. Among them, the seventh connection end 411 can also be a grounding end.

[0163] The feeding point 412 is electrically connected to the fourth feeder 42 through the fourth matching circuit M4. The free end 413 is spaced from the fourth side 404.

[0164] When the fourth antenna unit 40 generates a resonance mode, the resonance current formed on the first loop radiator 11 flows from the free end 413 to the seventh connection end 411. Due to the periodicity of the current, the resonance current formed on the first loop radiator 11 can also flow from the seventh connection end 411 to the free end 413. Among them, the current excited by the fourth antenna unit 40 on the conductive middle frame 400 includes: flowing from the grounding end along the positive Y-axis to the first side 401 and along the first side 401 to the third side 403, and flowing from the grounding end along the negative Y-axis to the second side 402 and along the second side 402 to the third side 403. Thus, the equivalent current directions of the fourth antenna unit 40 include obliquely upward and obliquely downward to the left.

[0165] The far - field polarization direction of the fourth antenna unit 40 intersects (weakly orthogonal) or is orthogonal to the far - field polarization direction of the second antenna unit 20, and the far - field polarization direction of the fourth antenna unit 40 intersects (weakly orthogonal) or is orthogonal to the far - field polarization direction of the first antenna unit 10. The main radiation direction of the fourth antenna unit 40 in the far - field region intersects the main radiation direction of the third antenna unit 30 in the far - field region.

[0166] Figure 23 and Figure 24 are respectively the far - field pattern and the planar pattern of the fourth antenna unit 40. It can be seen from Figure 23 that the electric - field zero - point directions of the fourth antenna unit 40 are along the upper left - oblique and lower left - oblique directions, that is, the far - field electric - field polarization directions are along the upper left - oblique and lower left - oblique directions. And from Figure 12 it can be seen that the electric - field zero - point direction of the first antenna unit 10 is along the Y - axis direction, that is, the far - field polarization direction is along the Y - axis direction. From Figure 13 it can be seen that the electric - field zero - point direction of the second antenna unit 20 is along the Y - axis direction, that is, the far - field polarization direction is along the Y - axis direction. Obviously, the far - field polarization direction of the fourth antenna unit 40 intersects (weakly orthogonal) with the far - field polarization direction of the second antenna unit 20, and the far - field polarization direction of the fourth antenna unit 40 intersects (weakly orthogonal) with the far - field polarization direction of the first antenna unit 10, so as to achieve a lower envelope correlation coefficient between the adjacent fourth antenna unit 40 and the first antenna unit 10, and between the fourth antenna unit 40 and the second antenna unit 20, thereby improving the communication performance of the MIMO system.

[0167] From Figure 24 it can be seen that the main - radiation - direction region of the fourth antenna unit 40 tends to be biased towards the negative X - axis direction. Among them, the main - radiation - direction region of the third antenna unit 30 tends to be biased towards the positive Y - axis direction or the negative Y - axis direction. Therefore, the main - radiation - direction region of the third antenna unit 30 is different from that of the fourth antenna unit 40. The main radiation direction of the fourth antenna unit 40 intersects the main radiation direction of the third antenna unit 30. That is, the main - radiation - direction regions of the third antenna unit 30 and the fourth antenna unit 40 are different, and the energy distribution in their respective main radiation directions is small. The third antenna unit 30 and the fourth antenna unit 40 have good spatial independence, which is also conducive to forming a lower envelope correlation coefficient, thereby improving the communication performance of the MIMO system.

[0168] Figure 25 is the ECC result graph between the first antenna unit 10 and the fourth antenna unit 40. Taking 0.72 GHz - 0.78 GHz (for example, operating in the N28 band) as an example, it can be seen from Figure 25 that the ECC between the first antenna unit 10 and the fourth antenna unit 40 is less than 0.38, meeting the requirements of general operators (for example, less than 0.5).

[0169] Figure 26 It is the ECC result diagram between the third antenna unit 30 and the fourth antenna unit 40. Taking 0.72 GHz - 0.78 GHz (for example, operating in the N28 band) as an example, from Figure 26 it can be seen that the ECC between the third antenna unit 30 and the fourth antenna unit 40 is less than 0.022, meeting the requirements of general operators (for example, less than 0.5).

[0170] From another perspective, an electronic device 1000 provided by an embodiment of the present application includes the conductive middle frame 400 and a plurality of the antenna units 10a.

[0171] The conductive middle frame 400 includes the first side 401 and the second side 402 which are oppositely arranged.

[0172] The plurality of the antenna units 10a includes the first antenna unit 10 and the second antenna unit 20. The first antenna unit 10 and the second antenna unit 20 are respectively arranged on the first side 401 and the second side 402. The main radiation direction of the first antenna unit 10 in the far field region is opposite to the main radiation direction of the second antenna unit 20 in the far field region; wherein, the main radiation direction of the first antenna unit 10 in the far field region is the direction pointed by the main radiation beam of the radiation field formed by exciting the first antenna unit 10 in the region of the conductive middle frame 400 close to the second side 402. The far field region of the first antenna unit 10 is in the region of the conductive middle frame 400 close to the second side 402, for example Figure 4 the second region D2 in

[0173] The main radiation direction of the second antenna unit 20 in the far field region is the direction pointed by the main radiation beam of the radiation field formed by exciting the second antenna unit 20 in the region of the conductive middle frame 400 close to the first side 401. The far field region of the first antenna unit 10 is in the region of the conductive middle frame 400 close to the first side 401, for example Figure 5 the fourth region D4 in

[0174] The energy distribution regions of the first antenna unit 10 and the second antenna unit 20 are different, and the overlap degree is small, thereby improving the spatial independence of the first antenna unit 10 and the second antenna unit 20, increasing the isolation degree of the first antenna unit 10 and the second antenna unit 20, reducing the envelope correlation coefficient between the two, and improving the antenna performance of the plurality of the antenna units 10a.

[0175] It can be understood that the conductive middle frame 400, the first antenna unit 10, and the second antenna unit 20 in this embodiment are substantially the same as those in the previous embodiment, and will not be elaborated here one by one.

[0176] Among them, the first antenna unit 10 includes a first annular radiator 11. The first annular radiator 11 includes a first connection end 111 and a second connection end 112 that are close to each other. The first connection end 111 is electrically connected to the first side 401. The second connection end 112 is used to connect to the first matching circuit M1. The first annular radiator 11 forms a first current weak point between the first connection end 111 and the second connection end 112 in the resonance mode. Among them, the first current weak point in this embodiment is substantially the third current weak point B3 in the previous embodiment. A first current strong point A1 is formed at the first connection end 111. And a second current strong point A2 is formed at the second connection end 112. A part of the current of the first annular radiator 11 in the resonance mode flows from the first current strong point A1 of the first connection end 111 to the first current weak point. Another part of the current of the first annular radiator 11 in the resonance mode flows from the second current strong point A2 of the second connection end 112 to the first current weak point.

[0177] The conductive middle frame 400 further includes a pair of connecting sides connecting the first side 401 and the second side 402.

[0178] The first annular radiator 11 excites a first current distribution Q1 flowing from the second current weak point of the connecting side to the first current strong point A1 on the conductive middle frame 400 in the resonance mode. And excites a second current distribution Q2 flowing from the second current weak point to the second side 402. The second current weak point in this embodiment is substantially the first current weak point B1 in the previous embodiment.

[0179] Among them, the second antenna unit 20 includes a second annular radiator 21. The second annular radiator 21 includes a third connection end 211 and a fourth connection end 212 that are close to each other. The third connection end 211 is electrically connected to the second side 402. The fourth connection end 212 is used to connect to the second matching circuit M2. The second annular radiator 21 forms a third current weak point between the third connection end 211 and the fourth connection end 212 in the resonance mode. The third current weak point in this embodiment is substantially the fourth current weak point B4 in the previous embodiment.

[0180] A third current strong point A3 is formed at the third connection end 211. And a fourth current strong point A4 is formed at the fourth connection end 212. A part of the current of the second annular radiator 21 in the resonance mode flows from the third current strong point A3 of the third connection end 211 to the third current weak point. Another part of the current of the second annular radiator 21 in the resonance mode flows from the fourth current strong point A4 of the fourth connection end 212 to the third current weak point.

[0181] The second annular radiator 21 excites, in the resonance mode on the conductive middle frame 400, a third current distribution Q3 flowing from the fourth current weak point of the connection edge to the third current strong point A3, and a fourth current distribution Q4 flowing from the fourth current weak point to the first side 401. The fourth current weak point in this embodiment is substantially the second current weak point B2 in the previous embodiment.

[0182] For the electronic device 1000 provided in this application, by respectively arranging the first antenna unit 10 and the second antenna unit 20 on the opposite sides of the conductive middle frame 400, and enabling the first antenna unit 10 to excite, when in resonance, the first current distribution Q1 and the second current distribution Q2 with opposite current flows between the opposite sides of the conductive middle frame 400, and enabling the second annular radiator 21 of the second antenna unit 20 to excite, when in resonance, the third current distribution Q3 and the fourth current distribution Q4 with opposite current flows between the opposite sides of the conductive middle frame 400. The far - field main radiation direction of the first antenna unit 10 biases towards the direction where the second current distribution Q2 lags. The far - field main radiation direction of the second antenna unit 20 biases towards the direction where the fourth current distribution Q4 lags. Since the current flow directions of the second current distribution Q2 and the fourth current distribution Q4 are different, the region where the far - field main radiation direction of the first antenna unit 10 is located is different from the region where the far - field main radiation direction of the second antenna unit 20 is located, indicating that the energy distribution regions of the first antenna unit 10 and the second antenna unit 20 are different and have a small overlap degree. Furthermore, the spatial independence of the first antenna unit 10 and the second antenna unit 20 is improved, the isolation degree of the first antenna unit 10 and the second antenna unit 20 is increased, the envelope correlation coefficient between the two is reduced, and the antenna performance of multiple antenna units 10a is improved.

[0183] Optionally, the current flow direction of the second current distribution Q2 is opposite to that of the fourth current distribution Q4. For example, the current flow direction of the first current distribution Q1 is along the positive Y-axis, and the current flow direction of the second current distribution Q2 is along the negative Y-axis. The current flow direction of the third current distribution Q3 is along the negative Y-axis, and the current flow direction of the fourth current distribution Q4 is along the positive Y-axis. In this way, the current directions of the first antenna unit 10 and the second antenna unit 20 provided in the embodiments of the present application are opposite. At this time, the direction in which the area where the main radiation direction of the first antenna unit 10 is biased is opposite to the direction in which the area where the main radiation direction of the second antenna unit 20 is biased. In this way, it is realized that the energy radiation direction of the first antenna unit 10 is different from that of the second antenna unit 20, and the energy distribution of the first antenna unit 10 and the second antenna unit 20 in their respective energy radiation directions is small, that is, the coincidence degree of the energy distribution areas of the first antenna unit 10 and the second antenna unit 20 is low, further improving the correlation coefficient of the first antenna unit 10 and the second antenna unit 20 and improving the antenna performance.

[0184] Wherein, the operating mode of the first antenna unit 10 between the first current strong point A1 and the second current weak point is the 1 / 4 wavelength mode. The operating mode of the second antenna unit 20 between the third current strong point A3 and the fourth current weak point is the 1 / 4 wavelength mode. The fourth current weak point is located between the first current strong point A1 and the second current weak point. Or. The fourth current weak point coincides with the second current weak point. Or. The fourth current weak point is located between the second current weak point and the second side 402.

[0185] Wherein, the connecting side includes the third side 403 and the fourth side 404 which are oppositely arranged. The length of the third side 403 is greater than the length of the first side 401.

[0186] The plurality of antenna units 10a further includes a third antenna unit 30. The third antenna unit 30 includes a third annular radiator 31. The third annular radiator 31 is disposed on the third side 403 and is electrically connected to the conductive middle frame 400. The electric field polarization direction of the third antenna unit 30 in the far field intersects or is orthogonal to the electric field polarization direction of the first antenna unit 10 in the far field. The electric field polarization direction of the third antenna unit 30 in the far field intersects or is orthogonal to the electric field polarization direction of the second antenna unit 20 in the far field. It can be understood that the third antenna unit 30 in this embodiment is substantially the same as the third antenna unit 30 in the previous embodiment, and will not be described in detail here.

[0187] Through the above design, the far-field polarization direction of the third antenna unit 30 intersects or is orthogonal to the far-field polarization direction of the second antenna unit 20, and the far-field polarization direction of the third antenna unit 30 intersects or is orthogonal to the far-field polarization direction of the first antenna unit 10, so as to achieve a relatively low envelope correlation coefficient between two adjacent antenna units 10a, thereby improving the communication performance of the MIMO system. At the same time, the main radiation direction region of the third antenna unit 30 is different from the main radiation direction regions of the first antenna unit 10 and the second antenna unit 20. The energy distribution of the first antenna unit 10, the second antenna unit 20 and the third antenna unit 30 in their respective main radiation directions is small. The first antenna unit 10, the second antenna unit 20 and the third antenna unit 30 have good spatial independence, which is also conducive to forming a relatively low envelope correlation coefficient, thereby improving the communication performance of the MIMO system.

[0188] Among them, the multiple antenna units 10a further include a fourth antenna unit 40. The fourth antenna unit 40 includes an inverted-F radiator 41. The inverted-F radiator 41 is disposed on the fourth side 404 and electrically connected to the conductive middle frame 400. The electric field polarization direction of the fourth antenna unit 40 in the far field region intersects or is orthogonal to the electric field polarization direction of the first antenna unit 10 in the far field region. The electric field polarization direction of the fourth antenna unit 40 in the far field region intersects or is orthogonal to the electric field polarization direction of the second antenna unit 20 in the far field region. The main radiation direction of the fourth antenna unit 40 in the far field region intersects with the main radiation direction of the second antenna unit 20 in the far field region. It can be understood that the fourth antenna unit 40 in this embodiment is substantially the same as the fourth antenna unit 40 in the previous embodiment, and will not be elaborated here one by one.

[0189] Through the above design, the far-field polarization direction of the fourth antenna unit 40 intersects or is orthogonal to the far-field polarization direction of the second antenna unit 20, and the far-field polarization direction of the fourth antenna unit 40 intersects or is orthogonal to the far-field polarization direction of the first antenna unit 10, so as to achieve a relatively low envelope correlation coefficient between the adjacent fourth antenna unit 40 and the first antenna unit 10, and between the fourth antenna unit 40 and the second antenna unit 20, thereby improving the communication performance of the MIMO system. The main radiation direction region of the third antenna unit 30 is different from the main radiation direction region of the fourth antenna unit 40. The main radiation direction of the fourth antenna unit 40 intersects with the main radiation direction of the third antenna unit 30. That is, the main radiation direction regions of the third antenna unit 30 and the fourth antenna unit 40 are different, and the energy distribution in their respective main radiation directions is small. The third antenna unit 30 and the fourth antenna unit 40 have good spatial independence, which is also conducive to forming a relatively low envelope correlation coefficient, thereby improving the communication performance of the MIMO system.

[0190] The low-frequency band, such as the N28 band (703 - 733 MHz for uplink and 758 - 788 MHz for downlink), has the advantages of long coverage distance and good stability in low-frequency band communication. For a 5G communication system, reusing the low-frequency band communication is very important. Since this frequency band belongs to a relatively low frequency band, for the size of a mobile phone, the space occupied by this antenna is very large. Especially when designing a 4*4 MIMO antenna that supports the N28 band, the environment is very compact, and the envelope correlation coefficient between the antenna elements 10a is relatively poor, about 0.7, which will affect the communication performance of its MIMO system. The present application has made the following designs for the antenna assembly in the electronic device 1000. Starting from improving the performance of the MIMO system, the spatial correlation between multiple antennas is improved, thereby increasing the rank of the MIMO channel matrix and optimizing the throughput of the communication system.

[0191] The design of the antenna assembly in the electronic device 1000 in the present application is as follows: The present application provides a 4*4 MIMO antenna architecture, which is composed of a first antenna element 10, the second antenna element 20, a third antenna element 30, and a fourth antenna element 40 respectively. The first antenna element 10, the second antenna element 20, and the third antenna element 30 are all composed of a matching circuit, a feed source, a metal radiation loop, and an electrical connection of the metal radiation loop to the conductive middle frame 400; the fourth antenna element 40 is an IFA antenna (inverted F antenna), which is composed of a metal radiation frame, a matching circuit, a feed source, and an electrical connection of the metal radiation frame to the conductive middle frame 400.

[0192] Since the low-frequency band (0.7 - 0.96 GHz) belongs to the current golden frequency band for wireless communication, for a 5G communication system, reusing the low-frequency band communication is extremely necessary. The envelope correlation coefficient (ECC) between antennas is the most important indicator for measuring the spatial correlation of antennas. In the present application, through the basic principles of loop antennas and IFA antennas, antenna combinations are carried out to obtain a reasonable layout, so as to achieve good ECC between multiple antenna elements 10a and improve the communication performance of the MIMO antenna architecture.

[0193] Taking the loop antenna of the first antenna element 10 as an example. In the present application, a small inductor is fed at the end of the loop antenna (and the radiator) through a matching circuit, and the other end is grounded (i.e., connected to the conductive middle frame 400), as Figure 6 shown. According to the current distribution, it is symmetrically distributed around the structural center and is distributed in a quarter-wavelength. The center of the top of the loop antenna is at the weak point of the current, and the center of the bottom of the loop antenna (the contact position with the conductive middle frame 400) is at the strong point of the current. ECC is closely related to the polarization and far-field pattern between the two antenna elements 10a. For the far-field pattern of the loop antenna, its pattern is shown in Figure 9 andFigure 10 , since the length of the conductive middle frame 400 is about 140 mm, which is greater than one - quarter of the wavelength of the free - space electromagnetic wave, a reverse current distribution (i.e., the second current distribution Q2 in Figure 6 ) will appear, and the current phase lags in the reverse direction along the Y - axis. According to the theory of the array antenna, the main direction of far - field radiation will be along the direction of the current - element phase lag. Therefore, from Figure 9 and Figure 10 , the radiation strong points in the far - field plan view are all in the reverse direction of the Y - axis, that is, the main radiation direction area of the first antenna element 10 tends to the reverse direction of the Y - axis.

[0194] According to the above theory, the length of the conductive middle frame 400 is moderately increased, and the loop antennas are respectively placed at the top and bottom of the conductive middle frame 400, and by using the property that the main directions of far - field pattern radiation are opposite, good ECC performance is achieved between each of the antenna elements 10a. For example, Figure 11 the length of the conductive middle frame 400 is increased to 180 mm (about 0.48λ), and the first antenna element 10 and the second antenna element 20 are placed at the top and bottom. From Figure 12 and Figure 13 , it can be seen from the far - field pattern that the main radiation direction of the first antenna element 10 tends to the reverse direction of the Y - axis, and the main radiation direction of the second antenna element 20 tends to the positive direction of the Y - axis. Figure 15 also gives the ECC characteristics between the first antenna element 10 and the second antenna element 20. It can be seen that within the N28 frequency band, the ECC is less than 0.41, meeting the requirements of general operators.

[0195] Correspondingly, a third antenna (i.e., the third antenna element 30) is added to ensure good ECC characteristics with the first antenna element 10 and the second antenna element 20. Figure 16 In Figure 17 , the third antenna element 30 is placed on the third side 403 of the conductive middle frame 400. From the current in Figure 20 , it can be known that the current excited by the third antenna element 30 is perpendicular to the currents of the first antenna element 10 and the second antenna element 20. Since the lateral dimension of the conductive middle frame 400 is small, a pattern with the maximum radiation direction perpendicular to the X - axis will be generated, which is orthogonal to the patterns of the first antenna element 10 and the second antenna element 20. See the ECC between the third antenna element 30 and the first antenna element 10 given in

[0196] Figure 21 , correspondingly, a fourth antenna (i.e., the fourth antenna element 40) is added to the fourth side 404 of the conductive middle frame 400. The fourth antenna element 40 is an IFA antenna. The fourth antenna element 40 and its far - field pattern are shown in Figure 23, the main radiation direction of the fourth antenna unit 40 is along the negative X-axis direction.

[0197] In the context of refarming the low-frequency golden band, this antenna architecture utilizes the basic principle that the far-field pattern of a loop antenna changes with the size of the floor (i.e., the conductive middle frame 400). The first antenna unit 10 and the second antenna unit 20 are respectively arranged at the top and bottom of the conductive middle frame 400, so that the main radiation directions of the first antenna unit 10 and the second antenna unit 20 are opposite, thereby achieving better ECC characteristics. By using the loop antenna located on the third side 403, whose far-field pattern is orthogonal to the far-field patterns of the top and bottom (the far-field polarization directions are orthogonal), relatively small envelope correlations can be achieved among the antenna units 10a. Correspondingly, the IFA antenna is matched with the above three loop antennas to achieve better ECC characteristics among them. Starting from improving the performance of the MIMO system, the spatial correlation among multiple antennas is improved, thereby increasing the rank of the MIMO channel matrix and optimizing the throughput of the communication system. This solution uses the arrangement of loop antennas and IFA antennas to make the ECC between antennas less than 0.5, which can meet the actual requirements of operators and provide a practical solution for the design of low-frequency 4*4 MIMO.

[0198] The above are some embodiments of the present application. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present application, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present application.

Claims

1. An electronic device, characterized in that, Comprising: A conductive middle frame, including a first side and a second side disposed opposite to each other, and a pair of connecting sides connected between the first side and the second side; A first antenna unit, the first antenna unit including a first annular radiator, the first annular radiator being disposed on the first side and electrically connected to the conductive middle frame, the first annular radiator exciting a first current distribution and a second current distribution flowing in opposite directions on a pair of the connecting sides in a resonant mode, the first current distribution flowing from a first current weak point on the connecting side to the first side, and the second current distribution flowing from the first current weak point to the second side; And A second antenna unit, the second antenna unit including a second annular radiator, the second annular radiator being disposed on the second side and electrically connected to the conductive middle frame, the second annular radiator exciting a third current distribution and a fourth current distribution flowing in opposite directions on a pair of the connecting sides in a resonant mode, the third current distribution flowing from a second current weak point of the connecting side to the second side, and the fourth current distribution flowing from the second current weak point to the first side.

2. The electronic device according to claim 1, characterized in that, The first antenna unit further includes a first matching circuit and a first feed source; The first annular radiator includes a first connection end and a second connection end that are close to each other, the first connection end is electrically connected to the first side, the second connection end is electrically connected to the first feed source through the first matching circuit, the first annular radiator forms a third current weak point between the first connection end and the second connection end in a resonant mode, forms a first current strong point at the first connection end, and forms a second current strong point at the second connection end; a part of the current of the first annular radiator flows from the first current strong point of the first connection end to the third current weak point in a resonant mode, and another part of the current of the first annular radiator flows from the second current strong point of the second connection end to the third current weak point in a resonant mode.

3. The electronic device according to claim 2, characterized in that, The first annular radiator further includes a first extension section, a second extension section, and a third extension section connected in sequence, the second extension section is disposed opposite to the first side, both the first extension section and the third extension section are located between the second extension section and the first side, and the first extension section and the third extension section are arranged in sequence along the extending direction of the first side, the first connection end is the end of the first extension section connected to the conductive middle frame, the second connection end is the end of the third extension section connected to the first matching circuit, and the third current weak point is located on the second extension section.

4. The electronic device according to claim 2, characterized in that, The operating mode of the first antenna unit between the third current weak point and the first current strong point is a 1 / 4 wavelength mode, and the operating mode of the first antenna unit between the third current weak point and the second current strong point is a 1 / 4 wavelength mode.

5. The electronic device according to claim 2, characterized in that, The first matching circuit includes an inductor component, and the inductance value of the inductor component is less than a preset inductance value; or, the first matching circuit includes a 0 ohm resistor.

6. The electronic device according to claim 2, characterized in that, The operating mode of the first antenna unit between the second current weak point and the first current strong point is a 1 / 4 wavelength mode.

7. The electronic device according to any one of claims 2-6, characterized in that, The second antenna unit includes a second matching circuit and a second feed source. The second loop radiator includes a third connection end and a fourth connection end that are close to each other. The third connection end is electrically connected to the second side, and the fourth connection end is electrically connected to the second feed source through the second matching circuit. The second loop radiator forms a fourth current weak point between the third connection end and the fourth connection end, a third current strong point at the third connection end, and a fourth current strong point at the second connection end in the resonant mode. A part of the current of the second loop radiator flows from the third current strong point at the third connection end to the fourth current weak point in the resonant mode, and another part of the current of the second loop radiator flows from the fourth current strong point at the fourth connection end to the fourth current weak point in the resonant mode.

8. The electronic device according to any one of claims 2-6, characterized in that, The second current weak point is located between the first current strong point and the first current weak point; alternatively, the positions of the second current weak point and the first current weak point coincide; alternatively, the second current weak point is located between the first current weak point and the second side.

9. The electronic device according to any one of claims 1-6, characterized in that, The length between the first side and the second side is greater than or equal to 0.45λ, where λ is the dielectric wavelength corresponding to the frequency band supported by the first antenna unit.

10. The electronic device according to any one of claims 1-6, characterized in that, A pair of the connecting sides includes a third side and a fourth side that are oppositely arranged. The electronic device further includes a third antenna unit. The third antenna unit includes a third loop radiator disposed on the third side and electrically connected to the conductive middle frame. The third loop radiator excites a fifth current distribution and a sixth current distribution with opposite flowing directions on the third side during resonance. The fifth current distribution flows from the fifth current weak point on the third side to the third loop radiator, and the sixth current distribution flows from the fifth current weak point to the second side or the first side.

11. The electronic device according to claim 10, characterized in that, The third antenna unit further includes a third matching circuit and a third feed source. The third loop radiator includes a fifth connection end and a sixth connection end that are close to each other. The fifth connection end is electrically connected to the third side, and the sixth connection end is electrically connected to the third feed source through the third matching circuit. The third loop radiator forms a sixth current weak point between the fifth connection end and the sixth connection end, a fifth current strong point at the fifth connection end, and a sixth current strong point at the sixth connection end during resonance. A part of the current of the third loop radiator flows from the fifth current strong point at the fifth connection end to the sixth current weak point during resonance, and another part of the current of the third loop radiator flows from the sixth current strong point at the sixth connection end to the sixth current weak point during resonance.

12. The electronic device according to claim 10, characterized in that, The electronic device further includes a fourth antenna unit. The fourth antenna unit includes an inverted-F radiator disposed on the fourth side and electrically connected to the conductive middle frame. The inverted-F radiator forms at least a seventh current distribution on the fourth side during resonance, and the flowing direction of the seventh current distribution intersects with the flowing directions of the second current distribution, the fourth current distribution, and the fifth current distribution.

13. The electronic device according to claim 12, characterized in that, The fourth antenna unit further includes a fourth matching circuit and a fourth feed source. The inverted-F radiator includes a seventh connection end, a feeding point, and a free end arranged in sequence. The seventh connection end is electrically connected to the fourth side. The feeding point is electrically connected to the fourth feed source through the fourth matching circuit. The free end is spaced from the fourth side.

14. The electronic device according to claim 13, characterized in that, The electric field polarization direction of the fourth antenna unit in the far field intersects or is orthogonal to the electric field polarization direction of the first antenna unit in the far field. The electric field polarization direction of the fourth antenna unit in the far field intersects or is orthogonal to the electric field polarization direction of the second antenna unit in the far field. The main radiation direction of the fourth antenna unit in the far field intersects the main radiation direction of the third antenna unit in the far field.

15. An electronic device, characterized in that, Comprising: A conductive middle frame including a first side and a second side arranged opposite to each other; And Multiple antenna units including a first antenna unit and a second antenna unit. The first antenna unit and the second antenna unit are respectively arranged on the first side and the second side. The first antenna unit includes a first annular radiator. The main radiation direction of the first antenna unit in the far field is opposite to the main radiation direction of the second antenna unit in the far field; Wherein, the main radiation direction of the first antenna unit in the far field is the direction pointed by the main radiation beam of the radiation field formed by exciting the first antenna unit in the area of the conductive middle frame close to the second side. The main radiation direction of the second antenna unit in the far field is the direction pointed by the main radiation beam of the radiation field formed by exciting the second antenna unit in the area of the conductive middle frame close to the first side.

16. The electronic device according to claim 15, wherein The first annular radiator includes a first connection end and a second connection end close to each other. The first connection end is electrically connected to the first side. The second connection end is used to connect a first matching circuit. The first annular radiator forms a first current weak point between the first connection end and the second connection end, a first current strong point at the first connection end, and a second current strong point at the second connection end in the resonant mode. A part of the current of the first annular radiator in the resonant mode flows from the first current strong point of the first connection end to the first current weak point. Another part of the current of the first annular radiator in the resonant mode flows from the second current strong point of the second connection end to the first current weak point; The conductive middle frame further includes a pair of connection sides connecting the first side and the second side; The first annular radiator excites a first current distribution flowing from the second current weak point of the connection side to the first current strong point and a second current distribution flowing from the second current weak point to the second side on the conductive middle frame in the resonant mode.

17. The electronic device according to claim 16, wherein The second antenna unit includes a second loop radiator. The second loop radiator includes a third connection end and a fourth connection end that are close to each other. The third connection end is electrically connected to the second side. The fourth connection end is used to connect to a second matching circuit. The second loop radiator forms a third current weak point between the third connection end and the fourth connection end, a third current strong point at the third connection end, and a fourth current strong point at the fourth connection end in the resonance mode. A part of the current of the second loop radiator flows from the third current strong point at the third connection end to the third current weak point in the resonance mode, and another part of the current of the second loop radiator flows from the fourth current strong point at the fourth connection end to the third current weak point in the resonance mode. The second loop radiator excites a third current distribution flowing from the fourth current weak point of the connection side to the third current strong point and a fourth current distribution flowing from the fourth current weak point to the first side on the conductive middle frame in the resonance mode.

18. The electronic device according to claim 17, wherein The operating mode of the first antenna unit between the first current strong point and the second current weak point is the 1 / 4 wavelength mode. The operating mode of the second antenna unit between the third current strong point and the fourth current weak point is the 1 / 4 wavelength mode. The fourth current weak point is located between the first current strong point and the second current weak point, or the fourth current weak point coincides with the second current weak point, or the fourth current weak point is located between the second current weak point and the second side.

19. The electronic device according to claim 16, wherein The connection side includes a third side and a fourth side that are oppositely arranged, and the length of the third side is greater than the length of the first side. The plurality of antenna units further includes a third antenna unit. The third antenna unit includes a third loop radiator disposed on the third side and electrically connected to the conductive middle frame. The electric field polarization direction of the third antenna unit in the far field intersects or is orthogonal to the electric field polarization direction of the first antenna unit in the far field. The electric field polarization direction of the third antenna unit in the far field intersects or is orthogonal to the electric field polarization direction of the second antenna unit in the far field.

20. The electronic device according to claim 19, wherein The plurality of antenna units further includes a fourth antenna unit. The fourth antenna unit includes an inverted-F radiator disposed on the fourth side and electrically connected to the conductive middle frame. The electric field polarization direction of the fourth antenna unit in the far field intersects or is orthogonal to the electric field polarization direction of the first antenna unit in the far field. The electric field polarization direction of the fourth antenna unit in the far field intersects or is orthogonal to the electric field polarization direction of the second antenna unit in the far field. The main radiation direction of the fourth antenna unit in the far field intersects with the main radiation direction of the second antenna unit in the far field.

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