Communication terminal

Abstract

Provided in the present application is a communication terminal. The communication terminal comprises a bezel and an antenna system, the bezel being arranged around the circumference of the communication terminal. The antenna system comprises a radio frequency chip, at least two radiators arranged on the bezel, and a radiating branch, the at least two radiators being connected; the radio frequency chip is separately coupled to the at least two radiators by means of different feed points to form at least two antennas; the operating frequency band of each of the at least two antennas covers a first frequency band; the radiating branch is coupled to one of the radiators to form an annular structure, and the radiating branch is bent towards the radiator. In the communication terminal, the annular structure can be used for constraining current generated by one antenna from flowing to another antenna, which improves the isolation between at least two co-frequency antennas, thereby helping to improve the communication capability of the communication terminal. Furthermore, using the solution can effectively avoid slitting the bezel, thereby improving the structural strength, appearance attractiveness and consistency of the communication terminal.

Description

A communication terminal

[0001] Cross-reference to related applications

[0002] The present application claims priority to the Chinese patent application No. 202411345133.2, filed on September 25, 2024, and entitled "A communication terminal", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the field of communication technology, and in particular to a communication terminal. BACKGROUND

[0004] With the rapid development of communication technology and the popularity of smart phones, people's demand for communication terminals is becoming higher and higher. In particular, the requirement for the communication capability of the communication terminal is also becoming higher and higher. The communication capability of the communication terminal is realized through an antenna system, therefore, improving the performance of the antenna system of the communication terminal is an important development direction in the field.

[0005] At present, the antenna system of the communication terminal usually includes multiple antennas, and the multiple antennas can exist in simultaneous working and non-simultaneous working scenarios. In addition, the working frequency bands of the multiple antennas can cover at least one same frequency band, or the working frequency bands of the multiple antennas are all different. For the multiple antennas that work simultaneously and whose working frequency bands cover at least one same frequency band, isolation is a difficult problem. However, the existing scheme for improving isolation usually sacrifices the performance of the antenna system in some application scenarios, or is only suitable for improving the isolation of a single frequency band or a small number of radiators, in short, it cannot meet the requirements of the communication of the antenna system of the communication terminal for isolation. SUMMARY

[0006] The communication terminal provided by the present application includes an antenna system, and the isolation of the antenna system is improved to improve the communication capability of the communication terminal.

[0007] The application provides a communication terminal, which comprises a frame and an antenna system. The frame is arranged around the circumference of the communication terminal and comprises a first frame edge, a second frame edge, a third frame edge and a fourth frame edge connected in sequence. The first frame edge and the third frame edge are arranged oppositely, and the second frame edge and the fourth frame edge are arranged oppositely. The antenna system comprises a first radiator, a second radiator, a first radiation branch and a radio frequency chip. The first radiator is arranged on the first frame edge, the second frame edge and the fourth frame edge. The second radiator is arranged on the second frame edge, the third frame edge or the fourth frame edge. The first radiator and the second radiator are connected. The first radiation branch comprises a first end portion and a second end portion. The first end portion is coupled with the second frame edge, and the second end portion is coupled with the fourth frame edge. The first radiation branch is coupled with the first radiator through the first end portion and the second end portion to form a first annular structure. The part of the first radiation branch between the first end portion and the second end portion is bent towards the first frame edge. The first port of the radio frequency chip is coupled with the first radiator through a first feeding point to form a first antenna. The second port of the radio frequency chip is coupled with the second radiator through a second feeding point to form a second antenna. The working frequency range of the first antenna and the working frequency range of the second antenna both cover a first frequency range. In the communication terminal provided by the application, the working frequency range of the first radiator and the working frequency range of the second radiator both cover the first frequency range. Therefore, the antenna system comprises at least two same-frequency antennas. In addition, in the antenna system, the first annular structure is formed by the first radiation branch and the first radiator. The majority of the current generated by the working of the first antenna is restrained in the area between the connection line of the first end portion and the second end portion to the first frame edge. Therefore, the isolation between the first antenna and the second antenna can be effectively improved, which is beneficial to improving the communication capability of the communication terminal. In addition, the structure strength, the appearance aesthetics and the consistency of the communication terminal can be improved by avoiding the opening of the frame.

[0008] In a possible implementation of the application, the projection length of the first radiation branch on the second frame edge in the direction from the first frame edge to the third frame edge is L11. The length L11 and the circumference L1 of the first annular structure satisfy the following relationship: L11≥(1 / 16)×L1. In this way, the restraint effect on the current generated by the working of the first antenna can be improved, so that the isolation of the antenna system can be improved.

[0009] In addition, in actual application, the length L11 and the circumference L1 of the first annular structure can satisfy the following relationship: (1 / 8)×L1≤L11≤(1 / 4)×L1. In this way, the bending degree of the first radiation branch to the first frame edge direction can be increased, so that the distance between the first radiation branch and the first frame edge can be reduced. Therefore, the restraint effect on the current generated by the working of the first antenna can be further improved, which is beneficial to improving the isolation between the first antenna and the second antenna.

[0010] In the specific setting of the first annular structure, the circumference L1 of the first annular structure satisfies (n+1) x lambda x 0.8 < L1 < (n+1) x lambda x 1.2, where n is an integer greater than or equal to 1, and lambda is a medium wavelength corresponding to the operating frequency of the first antenna. This satisfies the radiation requirement of the antenna mode in which the first antenna operates.

[0011] In one possible embodiment of the present application, the minimum distance L12 from the part of the first radiating branch that is bent towards the first frame edge to the second frame edge satisfies L12 >= (1 / 20) x lambda. Similarly, the minimum distance L13 from the part of the first radiating branch that is bent towards the first frame edge to the fourth frame edge satisfies L13 >= (1 / 20) x lambda. Where lambda is a medium wavelength corresponding to the operating frequency of the first antenna. This ensures that the first radiating branch can effectively isolate the first antenna, thereby ensuring the isolation between the first antenna and the second antenna.

[0012] In addition, in the present application, the length L14 of the first radiating branch satisfies 0.8 x n x (1 / 2) x lambda <= L14 <= 1.2 x n x (1 / 2) x lambda, where n is an integer greater than or equal to 1, and lambda is a medium wavelength corresponding to the operating frequency of the first antenna. This can satisfy the communication requirement of the first antenna while ensuring that the first radiating branch can effectively isolate the first antenna.

[0013] In the communication terminal provided by the present application, the third port of the radio frequency chip is coupled with the first radiating body through the third feeding point to form a third antenna, and the operating frequency range of the third antenna and the operating frequency range of the first antenna both cover the first frequency range. And along the circumference of the first annular structure, the length L15 of the part between the first feeding point and the third feeding point satisfies (2n) x (1 / 4) x lambda <= L15 <= (2n+1) x (1 / 2) x lambda, where n is an integer greater than or equal to 0, and lambda is a medium wavelength corresponding to the operating frequency of the first antenna. This can excite a group of resonant modes through the first antenna and the third antenna to improve the isolation of the first antenna and the third antenna.

[0014] In one possible implementation of the present application, when the positions of the first feeding point and the third feeding point are set, the first feeding point can be set at the first frame edge, and the third feeding point can be set at the second frame edge. This makes the distance between the first feeding point and the third feeding point smaller, so as to facilitate the excitation of the resonant mode.

[0015] In addition, the distance d from the first feeding point to the midpoint of the first frame edge and the length L111 of the first frame edge satisfy 0 <= d <= (1 / 4) x L111; and the distance L15 from the third feeding point to the first feeding point satisfies (1 / 8) x L1 <= L15 <= (3 / 2) x L1. This makes the first antenna and the third antenna more easily excite the resonant mode.

[0016] In a possible implementation of the present application, when the first antenna and the third antenna are excited in a capacitive manner, the first feed point is located at an electric field null of the third antenna, and the third feed point is located at an electric field null of the first antenna. When the first antenna and the third antenna are excited in an inductive manner, the first feed point is located at a current null of the third antenna, and the third feed point is located at a current null of the first antenna. In this way, the communication requirement of the first antenna can be met, and the first radiating branch can also meet the requirement of isolation.

[0017] In the present application, the position of the first radiating branch can also be set to adjust the isolation. For example, in a possible implementation, the first end of the first radiating branch is connected to a current strong point of the first antenna, and the second end is connected to another current strong point of the first antenna. Alternatively, the first end can be connected to a current strong point of the third antenna, and the second end can be connected to another current strong point of the third antenna. In this way, the isolation effect of the first radiating branch can be improved.

[0018] As described above, in the present application, a set of resonant modes can be excited by the first antenna and the third antenna to improve the isolation between the first antenna and the third antenna. Based on this, in a possible implementation, the first antenna and the third antenna can be used to excite a set of orthogonal modes. In this way, a high isolation effect can be generated to improve the isolation between the first antenna and the third antenna.

[0019] In actual applications, the first antenna can be used to excite a symmetric mode, and the third antenna can be used to excite an anti-symmetric mode. Alternatively, the first antenna can be used to excite an anti-symmetric mode, and the third antenna can be used to excite a symmetric mode. In this way, the first antenna and the third antenna can excite a set of orthogonal modes to generate a high isolation effect.

[0020] As described above, the first radiating branch is a bent structure. In a possible implementation of the present application, the portion of the first radiating branch bent towards the first frame edge can be bent in a C shape or a snake shape. In this way, the first radiating branch can be miniaturized while meeting the isolation requirement of the first antenna and the third antenna, thereby facilitating the reduction of the space occupied by the first radiating branch in the communication device. In other implementations, the first radiating branch can also have other bending forms, which are not limited in the present application.

[0021] To further improve the isolation effect of the antenna system, in a possible implementation of the present application, the antenna system further comprises a second radiating branch, a projection of the second radiating branch falls within the projection profile of the first radiating body along the direction from the second frame edge to the fourth frame edge. The second radiating branch comprises a third end portion and a fourth end portion, the third end portion is coupled with the second frame edge, the fourth end portion is coupled with the fourth frame edge, the third end portion is closer to the third frame edge relative to the first end portion, and the fourth end portion is closer to the third frame edge relative to the second end portion, so that the second radiating branch has no overlapping part with the first radiating branch. In addition, the second radiating branch is coupled with the first radiating body through the third end portion and the fourth end portion to form a closed third annular structure, and a part of the second radiating branch between the third end portion and the fourth end portion is bent towards the first frame edge. In this way, the first annular structure and the third annular structure are arranged to improve the isolation degree of the antenna system.

[0022] In the specific arrangement of the second radiating branch, the length L16 satisfies: n×(1 / 8)×λ≤L16≤n×(3 / 8)×λ, where n is an integer greater than or equal to 1, and λ is the medium wavelength corresponding to the working frequency of the first antenna. In this way, the communication requirements of the first antenna can be met while ensuring that the second radiating branch can achieve the required isolation effect.

[0023] In a possible implementation of the present application, the antenna system further comprises a third radiating branch, a projection of the third radiating branch falls within the projection profile of the second radiating body along the direction from the second frame edge to the fourth frame edge. The third radiating branch comprises a fifth end portion and a sixth end portion, the fifth end portion is coupled with the second frame edge, the sixth end portion is coupled with the fourth frame edge, the fifth end portion is closer to the third frame edge relative to the first end portion, and the sixth end portion is closer to the third frame edge relative to the second end portion, so that the third radiating branch has no overlapping part with the first radiating branch. In addition, the third radiating branch is connected with the second radiating body to form a closed third annular structure, and a part of the third radiating branch between the fifth end portion and the sixth end portion is bent towards the third frame edge. In this way, the first radiating branch can bind the current generated by the working of the first antenna, and the third radiating branch can bind the current generated by the working of the second antenna, so that the isolation degree between the first antenna and the second antenna can be effectively improved to improve the communication capability of the communication terminal.

[0024] In the specific arrangement of the third radiating branch, along the direction from the first frame edge to the third frame edge, the projection length of the third radiating branch on the second frame edge is L21, and the length L21 and the circumference L2 of the third annular structure satisfy: L21≥(1 / 16)×L2. In this way, the current generated by the working of the second antenna can be more bound in the area between the line connecting the fifth end portion and the sixth end portion and the third frame edge, so as to improve the isolation effect.

[0025] In the present application, the circumference L2 of the second annular structure satisfies: (n+1) x lambda x 0.8 < L2 < (n+1) x lambda x 1.2, where n is an integer greater than or equal to 1, and lambda is the wavelength of the second antenna in the medium corresponding to the operating frequency. This satisfies the radiation requirement of the antenna mode in which the second antenna operates.

[0026] In addition, the length L22 of the third radiating branch satisfies: 0.8 x n x (1 / 2) x lambda <= L22 <= 1.2 x n x (1 / 2) x lambda, where n is an integer greater than or equal to 1, and lambda is the wavelength of the second antenna in the medium corresponding to the operating frequency. In this way, the third radiating branch can satisfy the required isolation effect while satisfying the communication requirement of the second antenna.

[0027] In the communication terminal provided in the present application, the fourth port of the radio frequency chip is coupled to the second radiator through the fourth feeding point to form a fourth antenna. The length L23 of the portion between the second feeding point and the fourth feeding point along the contour line of the third annular structure satisfies: (2n) x (1 / 4) x lambda <= L23 <= (2n+1) x (1 / 2) x lambda, where n is an integer greater than or equal to 0, and lambda is the wavelength of the second antenna in the medium corresponding to the operating frequency. In this way, a set of resonant modes can be excited by the third antenna and the fourth antenna to improve the isolation of the third antenna and the fourth antenna.

[0028] In addition, when the positions of the second feeding point and the fourth feeding point are set, the second feeding point can be arranged at the third frame edge, and the fourth feeding point can be arranged at the second frame edge or the fourth frame edge. In addition, when the excitation mode of the second antenna and the fourth antenna is capacitive excitation, the second feeding point is located at the electric field zero point of the fourth antenna, and the fourth feeding point is located at the electric field zero point of the second antenna. When the excitation mode of the second antenna and the fourth antenna is capacitive excitation, the second feeding point is located at the current zero point of the fourth antenna, and the fourth feeding point is located at the current zero point of the second antenna. In this way, the third radiating branch can satisfy the required isolation effect while satisfying the communication requirement of the second radiator.

[0029] In the present application, the position of the third radiating branch can also be set to achieve the purpose of adjusting the isolation. For example, in one possible implementation, the fifth end of the third radiating branch is connected to one current strong point of the second antenna, and the sixth end is connected to another current strong point of the second antenna. Alternatively, the fifth end is connected to one current strong point of the fourth antenna, and the sixth end is connected to another current strong point of the fourth antenna. In this way, the isolation effect between the second antenna and the fourth antenna can be improved.

[0030] As described above, in the present application, a set of resonant modes can be excited by the second antenna and the fourth antenna to improve the isolation of the second antenna and the fourth antenna. Based on this, in one possible implementation, the second antenna and the fourth antenna can be used to excite a set of orthogonal modes. This can facilitate the generation of a high isolation effect to improve the isolation between the second antenna and the fourth antenna.

[0031] In actual applications, the second antenna can be used to excite a symmetric mode, and the fourth antenna can be used to excite an anti-symmetric mode. Or the second antenna is used to excite an anti-symmetric mode, and the fourth antenna is used to excite a symmetric mode. In this way, the second antenna and the fourth antenna can excite a set of orthogonal modes, thereby generating a high isolation effect.

[0032] To further improve the isolation effect of the antenna system, in one possible implementation of the present application, the antenna system further includes a fourth radiation branch, and a projection of the fourth radiation branch falls within the contour range of the projection of the second radiator along the direction from the second frame edge to the fourth frame edge. The fourth radiation branch includes a seventh end portion and an eighth end portion, the seventh end portion is connected with the second frame edge, and the eighth end portion is connected with the fourth frame edge. The seventh end portion is located between the first end portion and the third end portion, and the eighth end portion is located between the second end portion and the fourth end portion, so that the fourth radiation branch does not overlap with the first radiation branch and the second radiation branch. In addition, the fourth radiation branch is coupled with the second radiator through the seventh end portion and the eighth end portion to form a closed fourth annular structure, and a portion of the fourth radiation branch between the seventh end portion and the eighth end portion is bent towards the third frame edge. In this way, the isolation between the first antenna and the second antenna can be effectively improved, thereby improving the communication capability of the communication terminal.

[0033] When the fourth radiation branch is specifically arranged, the length L24 of the fourth radiation branch satisfies: n×(1 / 8)×λ≤L24≤n×(3 / 8)×λ, where n is an integer greater than or equal to 1, and λ is the medium wavelength corresponding to the working frequency of the second antenna. In this way, the communication requirements of the second antenna can be met while ensuring that the fourth radiation branch can achieve the required isolation effect.

[0034] In a possible implementation of the present application, the antenna system further comprises a third radiator and a fourth radiator, the third radiator is arranged on the fourth frame edge, and the fourth radiator is arranged on the second frame edge; the first radiator, the third radiator, the second radiator and the fourth radiator are connected into a closed integrated structure. In addition, the fifth port of the radio frequency chip is coupled with the third radiator through a fifth feeding point to form a fifth antenna, and the sixth port of the radio frequency chip is coupled with the fourth radiator through a sixth feeding point to form a sixth antenna, wherein the operating frequency range of the first antenna, the operating frequency range of the second antenna, the operating frequency range of the third antenna and the operating frequency range of the fourth antenna all cover the first frequency range. The antenna isolation design scheme provided in the present application can also achieve good isolation effect when applied to an antenna system comprising multiple same-frequency antennas, thereby ensuring the communication performance of the communication terminal.

[0035] In the communication terminal provided in the present application, the fifth antenna and the sixth antenna can be used to excite a set of orthogonal modes. In this way, high isolation effect can be achieved between the fifth antenna and the sixth antenna and other antennas, thereby improving the isolation degree of the antenna system.

[0036] In actual application, the fifth antenna can be used to excite a symmetric mode, and the sixth antenna can be used to excite an anti-symmetric mode. Alternatively, the fifth antenna is used to excite an anti-symmetric mode, and the sixth antenna is used to excite a symmetric mode. In this way, the fifth antenna and the sixth antenna can excite a set of orthogonal modes, thereby achieving high isolation effect.

[0037] The scheme for improving the isolation degree of the antenna system provided in the present application is not only applicable to a completely closed metal frame, but also applicable to a non-closed frame comprising an opening. For example, in a possible implementation, the second frame edge comprises an opening, and the opening is located between the first radiator and the second radiator. In addition, the antenna system further comprises a third radiator, the third radiator is arranged on the fourth frame edge, and the first radiator, the third radiator and the second radiator are sequentially connected. Moreover, the operating frequency range of the first antenna, the operating frequency range of the second antenna and the operating frequency range of the third antenna all cover the first frequency range. In this way, high isolation effect can still be achieved between the antennas, thereby improving the communication performance of the communication terminal.

[0038] On the basis of the design principle of the antenna system provided in the present application, other structures capable of blocking the flow of current can also be added to improve the isolation degree. For example, in a possible implementation, the communication terminal further comprises a housing and a floor, the frame is arranged on the housing, the floor is arranged on or in the housing, and the frame is arranged around the floor. Based on this, the floor can comprise at least one slit, and the at least one slit is located between the first radiator and the second radiator along the direction from the first frame edge to the third frame edge. In this way, the slit on the floor can block the transmission path of the current generated by the antennas, thereby improving the isolation degree between the antennas of the antenna system.

[0039] In the present application, the length L3 of the slit of the floor satisfies: n×(1 / 8)×λ≤L3≤n×(3 / 8)×λ, where n is an integer greater than or equal to 1, and λ is the medium wavelength corresponding to the operating frequency of the first antenna or the second antenna. In this way, the communication requirements of the respective antennas can be met while ensuring that the slit of the floor can meet the required isolation effect. BRIEF DESCRIPTION OF DRAWINGS

[0040] Fig. 1 is a schematic diagram of a structure of a communication terminal according to an embodiment of the present application;

[0041] Fig. 2 is a schematic diagram of another structure of a communication terminal according to an embodiment of the present application;

[0042] Fig. 3 is a schematic diagram of a structure of an antenna box according to an embodiment of the present application;

[0043] Fig. 4 is a schematic diagram of a structure of an antenna system of a communication terminal according to an embodiment of the present application;

[0044] Fig. 5 is a schematic diagram of another structure of an antenna system of a communication terminal according to an embodiment of the present application;

[0045] Figs. 6a and 6b are schematic diagrams of two first loop structures according to an embodiment of the present application, in which a first feed point and a third feed point are arranged at different positions;

[0046] Fig. 7 is a S-parameter curve of the first antenna and the third antenna in the structure shown in Figs. 6a and 6b;

[0047] Fig. 8a is a schematic diagram of an excitation mode of the first antenna of an antenna system according to an embodiment of the present application;

[0048] Fig. 8b shows the electric field distribution excited by the first antenna as shown in Fig. 8a;

[0049] Fig. 9a is a schematic diagram of an excitation mode of the third antenna of an antenna system according to an embodiment of the present application;

[0050] Fig. 9b shows the electric field distribution excited by the third antenna as shown in Fig. 9a;

[0051] Fig. 10 is a schematic diagram of a structure of an LC series resonant circuit according to an embodiment of the present application;

[0052] Fig. 11a is a schematic diagram of another structure of a first loop structure according to an embodiment of the present application;

[0053] Fig. 11b is a schematic diagram of another structure of a first loop structure according to an embodiment of the present application;

[0054] Fig. 12 is a S-parameter curve of the first antenna and the third antenna in the structure shown in Figs. 11a and 11b.

[0055] Fig. 13a is a schematic diagram of an excitation pattern of a first antenna of an antenna system according to an embodiment of the present application;

[0056] Fig. 13b shows an electric field distribution excited by the first antenna as shown in Fig. 13a;

[0057] Fig. 14a is a schematic diagram of an excitation pattern of a third antenna of an antenna system according to an embodiment of the present application;

[0058] Fig. 14b shows an electric field distribution excited by the third antenna as shown in Fig. 14a;

[0059] Fig. 15 is a schematic diagram of another structure of an antenna system of a communication terminal according to an embodiment of the present application;

[0060] Fig. 16 is a curve of S parameters of an antenna system without a first radiation branch and a second radiation branch and the antenna system shown in Fig. 15;

[0061] Fig. 17 is a schematic diagram of another structure of an antenna system of a communication terminal according to an embodiment of the present application;

[0062] Fig. 18 is a curve of S parameters of the antenna system shown in Fig. 17 and Fig. 15;

[0063] Fig. 19 is a schematic diagram of another structure of an antenna system of a communication terminal according to an embodiment of the present application;

[0064] Fig. 20 is a schematic diagram of another structure of an antenna system according to an embodiment of the present application;

[0065] Fig. 21 is a curve of S parameters of the antenna system shown in Fig. 15 and Fig. 20;

[0066] Fig. 22 is a schematic diagram of another structure of an antenna system of a communication terminal according to an embodiment of the present application;

[0067] Fig. 23 is a curve of S parameters of the first antenna, the second antenna, the third antenna and the fourth antenna of the antenna system shown in Fig. 22;

[0068] Fig. 24 is a schematic diagram of another structure of an antenna system of a communication terminal according to an embodiment of the present application;

[0069] Fig. 25a is a curve of isolation between the fifth antenna and other antennas of the antenna system shown in Fig. 24;

[0070] Fig. 25b is a curve of isolation between the sixth antenna and other antennas of the antenna system shown in Fig. 24;

[0071] Fig. 26 is a schematic diagram of a structure of an antenna system of an antenna box in practical application according to an embodiment of the present application;

[0072] Fig. 27a to Fig. 27d are several possible setting modes of the antenna system in the mobile terminal according to the embodiments of the present application.

[0073] Reference signs: 100 - cover plate; 200 - display screen / module; 300 - printed circuit board; 400 - middle frame; 500 - back cover; 600 - frame; 61 - first frame edge; 62 - second frame edge; 63 - third frame edge; 64 - fourth frame edge; 700 - antenna box; 701 - four-side metal frame; 702 - opening; 800 - display; 11 - first radiator; 12 - first radiating branch; 121 - first end; 122 - second end; 13 - first feeding point; 14 - third feeding point; 21 - second radiator; 22 - third radiating branch; 221 - fifth end; 222 - sixth end; 23 - second feeding point; 24 - fourth feeding point; 31 - second radiating branch; 311 - third end; 312 - fourth end; 41 - fourth radiating branch; 411 - seventh end; 412 - eighth end; 51 - floor; 511 - first slit; 512 - second slit; 71 - third radiator; 72 - fifth feeding point; 81 - fourth radiator; 82 - sixth feeding point. DETAILED DESCRIPTION

[0074] In order to make the objects, technical solutions and advantages of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the drawings. However, the example embodiments can be implemented in various forms, and should not be understood as being limited to the embodiments set forth herein. The same reference signs in the drawings represent the same or similar structures, and thus repeated description thereof will be omitted. The expressions of position and direction described in the embodiments of the present application are described with reference to the drawings, but can be changed as needed, and the changes made are included in the scope of protection of the present application. The drawings of the embodiments of the present application are only used to illustrate the relative positional relationship and do not represent the true proportions.

[0075] It should be noted that specific details are set forth in the following description in order to facilitate understanding of the present application. However, the embodiments of the present application can be implemented in various other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the connotations of the embodiments of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0076] Hereinafter, the terms that can occur in the embodiments of the present application are explained.

[0077] Radiating element: is the device in the antenna used to receive / send electromagnetic wave radiation. In some cases, the term "antenna" is understood in a narrow sense as a radiating element that changes the guided wave energy from a transmitter into radio waves, or converts radio waves into guided wave energy for radiating and receiving radio waves. The modulated high-frequency current energy (or guided wave energy) generated by the transmitter is transmitted to the transmitting radiating element via a feed line, which is converted into some polarized electromagnetic wave energy by the radiating element and radiated in the desired direction. The receiving radiating element converts the electromagnetic wave energy from a certain polarization direction in space into modulated high-frequency current energy, which is delivered to the input terminal of the receiver via a feed line.

[0078] RF chip: is a combination of all components of the antenna for receiving and transmitting radio frequency waves. In the case of a receiving antenna, the RF chip can be considered as the antenna part from the first amplifier to the front-end transmitter. In a transmitting antenna, the RF chip can be considered as the part after the last power amplifier. In some cases, the RF chip can also be understood as a feed unit. The RF chip has the function of converting radio waves into electrical signals and sending them to the receiver components. Usually, it is considered as part of the antenna system 3 for converting radio waves into electrical signals and vice versa. The antenna should be designed to consider the maximum power transmission possibility and efficiency. For this purpose, the antenna feed impedance must be matched to the load resistance. The antenna feed impedance is a combination of resistance, capacitance and inductance. To ensure maximum power transmission conditions, the two impedances (load resistance and feed impedance) should be matched. Matching can be done by considering the frequency requirements and design parameters of the antenna (such as gain, directivity and radiation efficiency).

[0079] Feed line: also called transmission line, refers to the connection line between the RF chip and the radiating element of the antenna. Transmission lines can directly transmit current waves or electromagnetic waves according to different frequencies and forms. The connection between the transmission line and the radiating element is usually called the feed point. Transmission lines include wire transmission lines, coaxial transmission lines, waveguides, or microstrip lines, etc. Transmission lines can include support antenna bodies or glass antenna bodies according to the implementation form. Transmission lines can be realized by LCP (Liquid Crystal Polymer), FPC (Flexible Printed Circuit), or PCB (Printed Circuit Board) according to the carrier.

[0080] Communication band / operating band: Regardless of the type of antenna, it always works within a certain frequency range (bandwidth). For example, an antenna supporting B40 band has an operating band including frequencies in the range of 2300MHz-2400MHz, or in other words, the operating band of the antenna includes the B40 band. The frequency range that meets the index requirements can be regarded as the operating band of the antenna. The width of the operating band is called the operating bandwidth. The operating bandwidth of an omnidirectional antenna can reach 3-5% of the center frequency. The operating bandwidth of a directional antenna can reach 5-10% of the center frequency. The bandwidth can be considered as a range of frequencies on both sides of the center frequency (for example, the resonant frequency of a dipole), within which the antenna characteristics are within an acceptable range of values.

[0081] The resonant band and the operating band can be the same or different, or their frequency ranges can partially overlap. In one embodiment, the resonant band of an antenna can cover multiple operating bands of the antenna.

[0082] Medium wavelength: refers to the wavelength of electromagnetic waves propagating in a medium at the operating band. For example, the operating band is [f1, f2], and the corresponding medium wavelength is also a range value [w1, w2]. Alternatively, in order to simplify the calculation, the above medium wavelength can also refer to the wavelength of electromagnetic waves propagating in a medium at the center frequency f0 of the operating band, at this time, the medium wavelength is a specific value w0.

[0083] Antenna return loss: can be understood as the ratio of the signal power reflected back to the antenna port to the antenna port transmission power. The smaller the signal reflected back, the greater the signal radiated into space through the antenna, and the greater the radiation efficiency of the antenna. The greater the signal reflected back, the smaller the signal radiated into space through the antenna, and the smaller the radiation efficiency of the antenna.

[0084] The antenna return loss can be represented by the S11 parameter, which belongs to the S parameter. S11 represents the reflection coefficient, and this parameter can represent the pros and cons of the antenna transmission efficiency.

[0085] In one embodiment, the S11 graph can be understood as a schematic diagram for representing the resonance generated by the antenna. In one embodiment, the resonance shown in the S11 graph in the part less than -6dB can be understood as the resonance frequency / frequency range / operating band generated by the antenna. The S11 parameter is usually negative, and the smaller the S11 parameter, the smaller the antenna return loss, the smaller the energy reflected back by the antenna itself, which means that the actual energy entering the antenna is more, and the radiation efficiency of the antenna is higher; the larger the S11 parameter, the larger the antenna return loss, and the lower the radiation efficiency of the antenna.

[0086] It should be noted that the S11 value of -6dB is generally used as a standard in engineering. When the S11 value of the antenna is less than -6dB, it can be considered that the antenna can work normally, or it can be considered that the antenna has better transmission efficiency.

[0087] Radiation efficiency: refers to the ratio of the power radiated by the antenna into space (i.e., the power of the electromagnetic wave portion effectively converted) to the active power input to the antenna. Among them, the active power input to the antenna = the input power of the antenna - the loss power; the loss power mainly includes the return loss power and the ohmic loss power of the metal and / or the dielectric loss power. Metal loss, dielectric loss are factors affecting radiation efficiency.

[0088] As can be understood by those skilled in the art, radiation efficiency is generally expressed in percentage, and there is a corresponding conversion relationship between percentage and dB. The closer the radiation efficiency is to 0dB, the better the radiation efficiency of the antenna is represented.

[0089] dB: decibel, a logarithmic concept with a base of ten. Decibel is only used to evaluate the ratio between one physical quantity and another physical quantity, and it itself has no physical dimension. The ratio between the two quantities increases by 10 times, and their difference can be expressed as 10 decibels. For example: A = "100", B = "10", C = "5", D = "1", then A / D = 20dB; B / D = 10dB; C / D = 7dB; B / C = 3dB. That is, a difference of 10 decibels between two quantities is a difference of 10 times, a difference of 20 decibels is a difference of 100 times, and so on. A difference of 3dB is a difference of 2 times between two quantities.

[0090] End: "end" in the first end / second end / third end / fourth end / ground end / open end of the main radiator, which cannot be understood as a point or end that is physically disconnected from other radiators. It can also be considered as a section of the main radiator including the first end point, which is the end point of the main radiator at the gap. For example, the first end of the main radiator can be considered as a section of the main radiator within one-eighth of the first wavelength range from the first end point, wherein the first wavelength can be the wavelength corresponding to the working frequency band of the main radiator, the wavelength corresponding to the center frequency of the working frequency band, or the wavelength corresponding to the resonance point. In an embodiment, the "end / point" can include a connection / coupling area on the radiator that couples other conductive structures, for example, a feed end / point can be a coupling area (e.g., an area facing a part of the feed structure) on the antenna radiator that couples the feed structure, and for example, a ground end / point can be a connection / coupling area on the antenna radiator that couples the ground structure.

[0091] Open end and closed end: In some embodiments, open end and closed end are for example relative to ground, closed end is grounded, open end is not grounded. In one embodiment, open end can also be referred to as floating end, free end, open end, or open circuit end. In one embodiment, closed end can also be referred to as grounded end, or short circuit end. It should be appreciated that in some embodiments, other conductors can be coupled through open end to transfer coupling energy (it can be appreciated that current is transferred).

[0092] In some embodiments, open end and closed end are for example relative to other conductors, closed end is electrically connected to other conductors, open end is not electrically connected to other conductors.

[0093] In some embodiments, open end and closed end are for example relative to other conductors, closed end is electrically connected to other conductors, open end is not electrically connected to other conductors.

[0094] In some embodiments, open end and closed end are for example relative to other conductors, closed end is electrically connected to other conductors, open end is not electrically connected to other conductors.

[0095] In some embodiments, open end and closed end are for example relative to other conductors, closed end is electrically connected to other conductors, open end is not electrically connected to other conductors.

[0096] In some embodiments, open end and closed end are for example relative to other conductors, closed end is electrically connected to other conductors, open end is not electrically connected to other conductors.

[0097] In some embodiments, open end and closed end are for example relative to other conductors, closed end is electrically connected to other conductors, open end is not electrically connected to other conductors.

[0098] Capacitance: can be understood as lumped capacitance and / or distributed capacitance. Lumped capacitance includes components that exhibit capacitance, such as a capacitor element; distributed capacitance (or distributed capacitance) includes the equivalent capacitance formed by two conductive pieces spaced apart by a certain gap.

[0099] Electrical length: the electrical length can refer to the physical length (i.e. mechanical length or geometric length) multiplied by the ratio of the transmission time of an electrical or electromagnetic signal in a medium to the time required for this signal to pass through the same distance in free space as the physical length of the medium, the electrical length can satisfy the following formula:

[0100] Wherein, L is the physical length, a is the transmission time of the electrical or electromagnetic signal in the medium, and b is the transmission time in free space.

[0101] Alternatively, the electrical length can also refer to the ratio of the physical length (i.e. mechanical length or geometric length) to the wavelength of the transmitted electromagnetic wave, the electrical length can satisfy the following formula:

[0102] Wherein, L is the physical length, and λ is the wavelength of the electromagnetic wave.

[0103] In some embodiments of the present application, the physical length of the radiator can be understood as within ±20% of the electrical length of the radiator, for example, within ±10%, or within ±5%.

[0104] In embodiments of the present application, the wavelength in a certain wavelength mode (such as a half-wavelength mode, etc.) of an antenna can refer to the wavelength of the signal radiated by the antenna. It should be understood that the wavelength of the radiated signal in air can be calculated as follows: wavelength = speed of light / frequency, wherein the frequency is the frequency of the radiated signal. The wavelength of the radiated signal in a medium can be calculated as follows: wavelength = (speed of light / √ε) / frequency, wherein ε is the relative permittivity of the medium, and the frequency is the frequency of the radiated signal.

[0105] For the convenience of understanding the communication terminal provided in the embodiments of the present application, the application scenario thereof is first introduced below. The communication terminal in the embodiments of the present application refers to a terminal with a communication function. Specifically, it can refer to a communication terminal using one or more of the following communication technologies: Bluetooth (BT) communication technology, global positioning system (GPS) communication technology, wireless fidelity (WiFi) communication technology, global system for mobile communications (GSM) communication technology, wideband code division multiple access (WCDMA) communication technology, long term evolution (LTE) communication technology, 5G communication technology, and other future communication technologies. The communication terminal in the embodiments of the present application can include a mobile terminal or a fixed terminal. For example, the mobile terminal can be a mobile phone, a tablet computer, a notebook computer, a smart bracelet, a smart watch, a smart helmet, and smart glasses, etc.; the fixed terminal can be a router, a smart television, a smart home, a smart speaker, and a desktop computer, etc. In addition, the above-mentioned communication terminal can also be a handheld device, a computing device with a wireless communication function, or other processing devices connected to a wireless modem, a vehicle-mounted device, a communication terminal in a 5G network, or a communication terminal in a future evolved public land mobile network (PLMN), etc., and the embodiments of the present application are not limited thereto.

[0106] First, FIG. 1 exemplarily shows a communication terminal provided in the embodiments of the present application, taking a mobile terminal such as a mobile phone as an example for illustration. As shown in FIG. 1, in an embodiment, the communication terminal includes a cover 100, a display 200, a printed circuit board (PCB) 300, a middle frame 400, and a rear cover 500. It should be understood that in some embodiments, the cover 100 can be a cover glass, and can also be replaced by a cover made of other materials, such as a cover made of ultra-thin glass material, a cover made of polyethylene terephthalate (PET) material, etc. In an embodiment, the above-mentioned cover 100, middle frame 400, and rear cover 500 can all be considered as belonging to a housing.

[0107] The cover plate 100 can be arranged close to the display screen 200 and can be mainly used for protecting and dustproofing the display screen 200.

[0108] In an embodiment, the display screen 200 can include a liquid crystal display (LCD) panel, a light emitting diode (LED) display panel, or an organic light-emitting diode (OLED) display panel, etc., which are not limited in the present application.

[0109] The middle frame 400 mainly serves as a support for the whole machine. In FIG. 1, the PCB 300 is arranged between the middle frame 400 and the back cover 500. It should be understood that, in an embodiment, the PCB 300 can also be arranged between the middle frame 400 and the display screen 200, which are not limited in the present application. The PCB 300 can be made of a flame-retardant material (FR-4) dielectric plate, a Rogers dielectric plate, a hybrid dielectric plate of Rogers and FR-4, etc. Here, FR-4 is a code of a flame-retardant material grade, and the Rogers dielectric plate is a high-frequency board. The PCB 300 carries electronic components such as radio frequency chips, etc.

[0110] In an embodiment, a metal layer can be arranged on the PCB 300. The metal layer can be used for grounding the electronic components carried on the PCB 300, and can also be used for grounding other components such as a bracket antenna, a frame antenna, etc. The metal layer can be referred to as a ground plate, a grounding plate, or a grounding layer. In an embodiment, the metal layer can be formed by etching metal on the surface of any one of the dielectric plates in the PCB 300. In an embodiment, the metal layer for grounding can be arranged on one side of the PCB 300 close to the middle frame 400. In an embodiment, the edge of the PCB 300 can be regarded as the edge of its grounding layer. In an embodiment, the metal middle frame 400 can also be used for grounding the above-mentioned components. The communication terminal can also have other ground plates / grounding plates / grounding layers, which are not described herein again.

[0111] The communication terminal can also include a battery (not shown in the figure). The battery can be arranged between the middle frame 400 and the back cover 500, or can be arranged between the middle frame 400 and the display screen 200, which are not limited in the present application. In some embodiments, the PCB 300 is divided into a main board and a sub-board, and the battery can be arranged between the main board and the sub-board. The main board can be arranged between the middle frame 400 and the upper edge of the battery, and the sub-board can be arranged between the middle frame 400 and the lower edge of the battery.

[0112] The communication terminal can also include a bezel 600, which can be formed of a conductive material such as metal. The bezel 600 can be disposed between the display 200 and the back cover 500 and extend circumferentially around the periphery of the communication terminal. The bezel 600 can have four sides that surround the display 200 and help secure the display 200. In one implementation, the bezel 600 made of metal material can be used directly as a metal bezel of the communication terminal, forming a metal bezel appearance, which is suitable for a metal industrial design (ID). In another implementation, the outer surface of the bezel 600 can also be a non-metal material, such as a plastic bezel, forming a non-metal bezel appearance, which is suitable for a non-metal ID.

[0113] The middle frame 400 can include the bezel 600, and the middle frame 400 including the bezel 600 as a one-piece can support the electronic devices in the entire machine. The cover plate 100 and the back cover 500 are respectively attached along the upper and lower edges of the bezel to form a housing of the communication terminal. Alternatively, the bezel 600 can not be considered as a part of the middle frame 400. In one embodiment, the bezel 600 can be connected to and integrally formed with the middle frame 400. In another embodiment, the bezel 600 can include a protruding member extending inwardly to be connected to the middle frame 400, for example, by a spring, a screw, welding, or the like. In one embodiment, the cover plate 100, the back cover 500, the bezel 600, and the middle frame 400 can be collectively referred to as a housing of the communication terminal. It should be understood that the "housing" can be used to refer to part or all of any one of the cover plate 100, the back cover 500, the bezel 600, or the middle frame 400, or part or all of any combination of the cover plate 100, the back cover 500, the bezel 600, or the middle frame 400.

[0114] The back cover 500 can be a back cover made of metal material; can be a back cover made of non-conductive material, such as a glass back cover, a plastic back cover, or the like non-metal back cover; or can be a back cover including both conductive material and non-conductive material.

[0115] In an embodiment, the frame 600 can at least partially serve as a radiator to receive / transmit radio frequency signals. The portion of the frame 600 serving as the radiator can be separated from other portions of the frame 400 or the middle frame 400, so as to ensure that the radiator has a good radiation environment. In an embodiment, an aperture can be provided near the portion of the frame 600 serving as the radiator. In an embodiment, the aperture can include an internal aperture provided inside the communication terminal, for example, an aperture that is not visible from the appearance of the communication terminal. In an embodiment, the internal aperture can be formed by any one of the middle frame 400, the battery, the circuit board, the back cover 500, the display screen 200, and other internal conductive components, or formed by a plurality of components together, for example, the internal aperture can be formed by a structural component of the middle frame 400. In an embodiment, the aperture can also include a slit / gap / slot provided on the frame 600. In an embodiment, the slit / gap / slot on the frame 600 can be a break formed on the frame 600, and the frame 600 is divided into two parts at the break, which are not directly connected. In an embodiment, the aperture can also include a slit / gap / slot provided on the back cover 500 or the display screen 200. In an embodiment, the back cover 500 includes a conductive material, and the aperture provided at the conductive material can be in communication with the slot or break of the frame 600, so as to form a continuous aperture on the appearance of the communication terminal.

[0116] In an embodiment, the radiator of the communication terminal can also be provided in the frame 600. The frame 600 includes a non-conductive material, and the radiator of the antenna can be located inside the communication terminal and arranged along the frame 600, or the radiator can be at least partially embedded in the non-conductive material of the frame. In an embodiment, the radiator is arranged against the non-conductive material of the frame 600, so as to minimize the volume occupied by the radiator and be closer to the outside of the communication terminal, thereby achieving better signal transmission effect. It should be noted that the radiator arranged against the frame 600 means that the radiator can be closely arranged against the frame 600, or can be arranged close to the frame 600, for example, the radiator and the frame 600 can have a small gap therebetween.

[0117] In an embodiment, the radiator of the communication terminal can also be arranged in the housing, such as a bracket antenna (not shown in FIG. 1). A gap can exist between the radiator arranged in the housing and other conductive parts inside the housing, so as to ensure that the radiator has a good radiation environment. In an embodiment, an aperture can be arranged near the radiator. In an embodiment, the aperture can include an aperture arranged inside the communication terminal, such as an aperture that is invisible from the appearance surface of the communication terminal. In an embodiment, the aperture inside can be formed by any one of or multiple of the following: the frame 600, the middle frame 400, the battery, the circuit board, the back cover 500, the display screen 200, and other internal conductive parts, such as the aperture inside can be formed by a structural part of the middle frame 400. In an embodiment, the aperture can also include a slit / slot / hole arranged on the frame 600. In an embodiment, the slit / slot / hole on the frame 600 can be a break formed on the frame 600, and the frame 600 is divided into two parts at the break, which are not directly connected. In an embodiment, the aperture can also include a slit / slot / hole arranged on the back cover 500 or the display screen 200. In an embodiment, the back cover 500 includes a conductive material, and the aperture arranged at the conductive material can be in communication with the slot or break of the frame 600, so as to form a continuous aperture on the appearance surface of the communication terminal. In an embodiment, the aperture on the back cover 500 or the display screen 200 can also be used to place other devices, such as a camera, and / or a sensor, and / or a microphone, and / or a speaker, and the like.

[0118] FIG. 1 only schematically shows some components included in the communication terminal, and the actual shape, actual size, and actual structure of the components are not limited by FIG. 1. In addition, FIG. 1 only shows some possible forms of the communication terminal, and in other embodiments, the above-mentioned communication terminal can also be a foldable mobile terminal or other terminal device having a communication function.

[0119] In addition, FIG. 2 exemplarily shows another communication terminal provided in an embodiment of the present application, and in this embodiment, a fixed terminal such as a smart large screen is taken as an example for illustration. As shown in FIG. 2, in order to realize a communication function, the smart large screen usually includes an antenna box 700, which is exemplarily arranged at a middle position on the top of a display 800, and of course can also be arranged at other positions of the display 800, as long as the communication performance of the antenna in the antenna box 700 can be ensured.

[0120] It can be understood that, compared with the mobile terminal shown in FIG. 1, the fixed terminal such as the smart large screen can be understood as adopting a split manner to arrange the display 800 and the antenna system, and the two are electrically connected through a circuit board or the like, so as to realize communication between the antenna system and the display 800.

[0121] At present, the antenna box 700 is usually a cuboid structure including a four-side metal frame 701. FIG. 3 is a structural schematic diagram of an antenna box provided by an embodiment of the present application. The four-side metal frame 701 of the antenna box 700 is similar to the setting mode of the frame of the communication terminal shown in FIG. 1, that is, the four-side metal frame 701 is arranged around the periphery of the antenna box 700 in a circumferential direction. In addition, the four-side metal frame 701 can be directly used as the appearance surface of the antenna box 700 to form a metal ID of the antenna box 700, or the four-side metal frame 701 can be at least partially embedded in a non-metal material, or the outer surface of the four-side metal frame can be a non-metal material, for example, plastic. It is worth mentioning that the outer surface of the four-side metal frame 701 being a non-metal material can be understood as the four-side metal frame 701 being arranged against a non-metal appearance surface, that is, the four-side metal frame 701 is closely attached to the non-metal appearance surface, or there is a small gap between the four-side metal frame 701 and the non-metal appearance surface. In addition, the four-side metal frame 701 can be a frame structure having a certain supporting function, or a metal coating arranged on the inner side of the appearance surface of the antenna box 700. In the present application, the specific setting form of the four-side metal frame 701 of the antenna box 700 is not limited.

[0122] Similar to the frame of the mobile terminal introduced above, at least part of the four-side metal frame 701 of the antenna box 700 can also be used as a radiator to transmit / receive radio frequency signals. In the present application, the antenna box 700 itself can also be regarded as a communication terminal.

[0123] In addition, based on the above introduction of the four-side metal frame 701 of the antenna box 700 and the frame of the mobile phone, in the following embodiments of the present application, structures similar to the four-side metal frame 701 of the antenna box 700 and the frame of the mobile phone can be collectively referred to as the frame of the communication terminal. In addition, regardless of the form of the frame of the communication terminal, it can be a completely closed structure or a non-closed frame including an opening.

[0124] Since the antenna system in the communication terminal usually includes multiple antennas for realizing communication functions. Regardless of the mobile terminal or the antenna box described above, the multiple antennas integrated inside can exist in a simultaneous working and non-simultaneous working scenario, in addition, the working frequency bands of the multiple antennas can cover at least one same frequency band, or the working frequency bands of the multiple antennas are all different. Usually, in order to ensure the communication stability of the multiple antennas, a certain isolation degree is required between the antennas. It can be understood that for the multiple antennas working simultaneously and covering at least one same frequency band, the requirement for isolation degree is higher.

[0125] Therefore, the communication terminal provided in the present application sets a radiation branch in the antenna system to improve the isolation of the antenna system, thereby improving the communication capability of the communication terminal. In order to make the purpose, technical solutions and advantages of the present application more clear, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0126] FIG. 4 is a structural schematic diagram of an antenna system of a communication terminal provided in an embodiment of the present application. As shown in FIG. 4, the frame of the communication terminal includes a first frame side 61, a second frame side 62, a third frame side 63 and a fourth frame side 64 connected in sequence, the first frame side 61 and the third frame side 63 are oppositely arranged, and the second frame side 62 and the fourth frame side 64 are oppositely arranged. It is worth mentioning that in the present application, the frame side can be not only a line, but also a surface, or a plate with obvious thickness.

[0127] In addition, the antenna system includes a first radiator 11, a second radiator 21 and a first radiation branch 12, the first radiator 11 is arranged on the first frame side 61, the second frame side 62 and the fourth frame side 64, the second radiator 21 is arranged on the third frame side 63, the second frame side 62 or the fourth frame side 64, and in the embodiment shown in FIG. 4, the second radiator 21 is arranged on the third frame side 63, the second frame side 62 and the fourth frame side 64 at the same time.

[0128] In the present application, the first radiator 11 and the second radiator 21 are connected. In addition, the antenna system further includes a radio frequency chip (not shown in FIG. 4), a first port of the radio frequency chip is coupled with the first radiator 11 through a first feeding point 13 to form a first antenna, a second port of the radio frequency chip is coupled with the second radiator 21 through a second feeding point 23 to form a second antenna, and the working frequency band of the first antenna and the working frequency band of the second antenna both cover a first frequency band, for example, the first frequency band can be a 2.4GHz Wi-Fi frequency band or a 5GHz Wi-Fi frequency band.

[0129] It is worth mentioning that the present application does not limit the specific arrangement form of the radio frequency chip, for example, the radio frequency chip can be an integral whole, and then each port of the radio frequency chip can be used to be coupled with a corresponding radiator to form different antennas respectively. Alternatively, in the present application, the radio frequency chips used to be coupled with different radiators are arranged respectively, and in the present application, the ports of the radio frequency chips coupled with different radiators refer to the ports of different radio frequency chips.

[0130] In addition, in the present application, the first radiator 11 and the second radiator 21 can be connected through a non-metallic part on the frame. Alternatively, the first radiator 11 and the second radiator 21 can be connected through a metallic part on the frame, or the first radiator 11 and the second radiator 21 can be directly connected, so that the first radiator 11 and the second radiator 21 are connected as an integral structure, which is beneficial to improving the integrity of the frame and can use the complete metallic frame as the radiator of multiple same-frequency antennas.

[0131] Referring to FIG. 4, the first radiating branch 12 includes a first end 121 and a second end 122, wherein the first end 121 is coupled with the second frame edge 62, the second end 122 is coupled with the fourth frame edge 64, and the first radiating branch 12 is coupled with the first radiator 11 through the first end 121 and the second end 122 to form a first loop structure.

[0132] In actual application, the specific position of the first radiator 11 on the frame can be determined by the positions of the connection points of the first end 121 and the second end 122 of the first radiating branch 12 with the frame, that is, the continuous metallic structure of the frame between the first end 121 and the second end 122 of the first radiating branch 12 and including the first frame edge 61 can be used as the first radiator 11. At least part of the frame between the first end 121 and the second end 122 of the first radiating branch 12, except the first radiator 11, can be used as the second radiator 21.

[0133] In addition, as shown in FIG. 4, in the embodiment of the present application, the part of the first radiating branch 12 between the first end 121 and the second end 122 is bent towards the first frame edge 61. So that the first radiating branch 12 and the first radiator 11 form a first loop structure in the shape of approximately U.

[0134] It can be understood that by using the above-mentioned antenna system solution provided by the present application, the length of the first radiator 11, the length of the first radiating branch 12, and the size of the part of the first radiating branch 12 bent towards the first frame edge 61 can be adjusted, so that most of the current generated by the first antenna working flows along the first loop structure, thereby confining most of the current generated by the first antenna working in the area between the line of the first end 121 and the second end 122 to the first frame edge 61, which is beneficial to improving the isolation between the first antenna and the second antenna, improving the stability of the first antenna and the second antenna working in the same frequency band, and further improving the communication performance of the communication terminal.

[0135] In addition, as can be known from the above introduction of the antenna system provided by the present application, since the first radiator 11 and the second radiator 21 are connected, the frame can be effectively avoided to be slotted, thereby improving the structural strength, appearance beauty and consistency of the communication terminal.

[0136] Continuing to refer to FIG. 4, in the embodiment of the present application, the length of the projection of the first radiating branch 12 on the second frame edge 62 in the direction from the first frame edge 61 to the third frame edge 63, i.e. the X direction shown in FIG. 4, is L11, and the length L11 and the circumference L1 of the first loop structure satisfy L11≥(1 / 16)×L1. In this way, the current generated by the operation of the first antenna can be more bound in the area between the line connecting the first end 121 and the second end 122 and the first frame edge 61, so as to improve the isolation effect.

[0137] In actual application, the length L11 and the circumference L1 of the first loop structure satisfy (1 / 8)×L1≤L11≤(1 / 4)×L1. In this way, the bending degree of the first radiating branch 12 in the direction of the first frame edge 61 can be increased to reduce the distance between the first radiating branch 12 and the first frame edge 61, so as to further improve the binding effect of the current generated by the operation of the first antenna, which is beneficial to improve the isolation between the first antenna and the second antenna.

[0138] In addition, in the present application, the minimum distance L12 of the part of the first radiating branch 12 bent towards the first frame edge 61 to the second frame edge 62 in the Y direction, i.e. the minimum distance of the part of the first radiating branch 12 bent towards the first frame edge 61 to the second frame edge 62, satisfies L12≥(1 / 20)×λ. Similarly, the minimum distance L13 of the part of the first radiating branch 12 bent towards the first frame edge 61 to the fourth frame edge 64 satisfies L13≥(1 / 20)×λ. Wherein, λ is the medium wavelength corresponding to the operating frequency of the first antenna. In this way, the first radiating branch 12 can effectively ensure the isolation effect, so as to ensure the isolation between the first antenna and the second antenna.

[0139] Since different radio frequency signals fed into the first radiating body 11 can excite corresponding resonance modes of the first antenna, and different resonance modes have different effects on the isolation, in actual application, the first radiating body 11 can be fed according to specific communication requirements. FIG. 5 is another structure schematic diagram of the antenna system of the communication terminal provided by the embodiment of the present application. In the embodiment shown in FIG. 5, the first port of the radio frequency chip is coupled with the first radiating body 11 through the first feeding point 13 to form the first antenna, and the first port of the radio frequency chip can feed radio frequency signals in the operating frequency band of the first antenna into the first radiating body 11 through the first feeding point 13. In addition, the third port of the radio frequency chip is coupled with the first radiating body 11 through the third feeding point 14 to form the third antenna, and the third port of the radio frequency chip can feed radio frequency signals in the operating frequency band of the third antenna into the first radiating body 11 through the third feeding point 14.

[0140] It is worth mentioning that in the present application, the operating frequency band of the first antenna and the operating frequency band of the third antenna can both cover the first frequency band, which can be, for example, the 2.4GHz Wi-Fi frequency band or the 5GHz Wi-Fi frequency band.

[0141] The present application does not limit the specific arrangement of the first feeding point 13 and the third feeding point 14 on the first annular structure. For example, in the embodiment shown in FIG. 5, the first feeding point 13 is arranged at the first frame edge 61, and the third feeding point 14 is arranged at the second frame edge 62.

[0142] In order to illustrate the influence of the arrangement position of the first feeding point 13 and the third feeding point 14 on the isolation of the antenna system, reference can be made to FIGS. 6a and 6b, which are structural schematic diagrams of two first annular structures provided by embodiments of the present application, in which the first feeding point and the third feeding point are arranged at different positions. It can be seen from the comparison that in the embodiments shown in FIGS. 6a and 6b, the arrangement position of the first feeding point 13 is the same, but the distance between the first feeding point 13 and the third feeding point 14 in the embodiment shown in FIG. 6b is greater than the above-mentioned distance in FIG. 6a.

[0143] In addition, reference can be made to FIG. 7, which is the S parameter curve of the first antenna and the third antenna in the structures shown in FIGS. 6a and 6b. Among them, case 1 represents the embodiment shown in FIG. 6a, and case 2 represents the embodiment shown in FIG. 6b. It can be seen from FIG. 7 that by using the design scheme shown in FIG. 6a, a decoupling notch can be generated at 2.42GHz, and the isolation of the first antenna and the third antenna can reach -30dB. However, due to the fact that in the design scheme shown in FIG. 6b, the distance between the first feeding point 13 and the third feeding point 14 is far, the isolation of the first antenna and the third antenna deteriorates to -2dB.

[0144] It can thus be understood that the distance between the first feeding point 13 and the third feeding point 14 has a great influence on the isolation of the antenna system. Then in a possible embodiment of the present application, the length L15 of the part between the first feeding point 13 and the third feeding point 14 along the circumference of the first annular structure satisfies: (2n)×(1 / 4)×λ≤L15≤(2n+1)×(1 / 2)×λ, and exemplarily, (2n+1)×(1 / 8)×λ≤L15≤(2n+1)×(3 / 8)×λ, where n is an integer greater than or equal to 0, and λ is the medium wavelength corresponding to the operating frequency of the first antenna. In this way, a set of resonant modes can be excited by the first antenna and the third antenna, so as to improve the isolation of the first antenna and the third antenna.

[0145] In the above embodiment, as shown in Fig. 5, the first feeding point 13 can be arranged at the first frame edge 61, and the third feeding point 14 can be arranged at the second frame edge 62. In addition, the distance d between the first feeding point 13 and the midpoint of the first frame edge 61 satisfies: 0≤d≤(1 / 4)×L111, and the distance L15 between the third feeding point 14 and the first feeding point 13 satisfies: (1 / 8)×L1≤L15≤(3 / 2)×L1. In this way, the first antenna and the third antenna can be more easily excited to resonate.

[0146] In practical applications, by adjusting the positions of the first feeding point 13 and the third feeding point 14 and the distance between them, the first antenna and the third antenna can be used to excite a set of orthogonal modes at appropriate positions. For example, the first antenna can be fed with a radio frequency signal so as to be used to excite a symmetric mode as shown in Fig. 8a. In addition, Fig. 8b shows the electric field distribution excited by the first antenna as shown in Fig. 8a.

[0147] Meanwhile, the third antenna can also be used to excite an anti-symmetric mode as shown in Fig. 9a. In addition, Fig. 9b shows the electric field distribution excited by the third antenna as shown in Fig. 9a.

[0148] As can be seen from Figs. 8a and 8b and Figs. 9a and 9b, in the present application, by exciting a symmetric mode by the first antenna and exciting an anti-symmetric mode by the third antenna, a high isolation effect can be achieved. This is because the first loop structure formed by the first radiating branch 12 and the first radiator 11 can constitute an LC series resonance circuit as shown in Fig. 10, which can effectively improve the isolation of the first antenna and the third antenna.

[0149] It is worth mentioning that in a possible embodiment of the present application, when the first antenna and the third antenna are excited in a capacitive manner, the first feeding point 13 can be located at the electric field zero point of the third antenna, and the third feeding point 14 can be located at the electric field zero point of the first antenna. When the first antenna and the third antenna are excited in an inductive manner, the first feeding point 13 can be located at the current zero point of the third antenna, and the third feeding point 14 can be located at the current zero point of the first antenna. In this way, the communication requirements of the first radiator 11 can be met while ensuring that the first radiating branch 12 can achieve the required isolation effect.

[0150] In the above embodiments, the first feeding point 13 is arranged at the first frame edge 61, and the third feeding point 14 is arranged at the second frame edge 62, as an example, the influence of the arrangement mode of the two feeding points on the isolation effect is introduced. In other possible embodiments, at least one of the first feeding point 13 and the third feeding point 14 can be arranged at the first radiation branch 12, and the distance between the two feeding points can be adjusted to excite a set of orthogonal modes at a suitable position of the first antenna and the third antenna, so as to meet the isolation requirement of the first antenna and the third antenna.

[0151] In the embodiments of the present application, the circumference L1 of the first annular structure satisfies: (n+1) x λ x 0.8 < L1 < (n+1) x λ x 1.2, where n is an integer greater than or equal to 1, and λ is the medium wavelength corresponding to the working frequency band of the first antenna. In this way, the radiation requirement of the antenna mode in which the first antenna works can be met, and the communication stability of the antenna system can be improved.

[0152] It is worth mentioning that in the above formula, λ in (n+1) x λ x 0.8 is the medium wavelength corresponding to the minimum working frequency point in the working frequency of the first antenna, and λ in (n+1) x λ x 1.2 is the medium wavelength corresponding to the maximum working frequency point in the working frequency of the first antenna.

[0153] It can be understood that the circumference of the first annular structure is the sum of the length of the first radiator 11 and the length of the first radiation branch 12. Wherein, the length of the first radiation branch 12 can be understood as the straight line length of the first radiation branch 12 after being straightened along the direction from the first end 121 to the second end 122, and the length of the first radiator 11 is the straight line length of the first radiator 11 after being straightened along the direction from the first end 121 to the second end 122. In addition, when the first radiation branch 12 is coupled to the first radiator 11 through a device or a gap, the circumference of the first annular structure is still the length of the complete annular structure.

[0154] In actual application, the length ratio of the first radiator 11 and the first radiation branch 12 can be adjusted according to specific design needs. For example, referring to FIG. 11a, FIG. 11a is another structure schematic diagram of the first annular structure provided by the embodiments of the present application. Compared with the first annular structure shown in FIG. 6a, in FIG. 11a, the length ratio of the first radiation branch 12 and the first radiator 11 is reduced.

[0155] In addition, FIG. 11b also shows another structure schematic diagram of the first annular structure provided by the embodiments of the present application. In FIG. 11a and FIG. 11b, the position of the first feeding point 13 is the same, but the distance between the first feeding point 13 and the third feeding point 14 is different.

[0156] Referring to FIG. 12, FIG. 12 is a S-parameter curve of the first antenna and the third antenna in the structure shown in FIG. 11a and FIG. 11b. Wherein, case 1 represents the embodiment shown in FIG. 11a, and case 2 represents the embodiment shown in FIG. 11b. As can be seen from FIG. 12, by using the design scheme shown in FIG. 11a, a decoupling notch can be generated at 2.42 GHz, and the isolation of the first antenna and the third antenna can reach -23 dB. However, due to the long distance between the first feeding point 13 and the third feeding point 14 in the design scheme shown in FIG. 11b, the isolation of the first antenna and the third antenna is deteriorated to -1 dB.

[0157] As can also be seen from the comparison in FIG. 12, by adjusting the distance between the two feeding points, the resonant mode excited by the first antenna and the third antenna can be adjusted, so as to adjust the isolation of the first antenna and the third antenna.

[0158] In actual application, the first antenna and the third antenna can still be used to excite a set of orthogonal modes at appropriate positions. For example, the first antenna can be used to excite a symmetric mode as shown in FIG. 13a, and in addition, FIG. 13b shows the electric field distribution excited by the first antenna as shown in FIG. 13a. Meanwhile, the third antenna can also be used to excite an anti-symmetric mode as shown in FIG. 14a. In addition, FIG. 14b shows the electric field distribution excited by the third antenna as shown in FIG. 14a.

[0159] As can be seen from the above FIG. 13a and FIG. 13b and FIG. 14a and FIG. 14b, in the present application, by exciting a symmetric mode by the first antenna and exciting an anti-symmetric mode by the third antenna, a high isolation effect can be generated, which can effectively improve the isolation of the first antenna and the third antenna.

[0160] In the above embodiments, the first antenna is used to excite a symmetric mode and the third antenna is used to excite an anti-symmetric mode as an example to illustrate the isolation effect generated thereby. In other embodiments of the present application, the first antenna can also be used to excite an anti-symmetric mode and the third antenna can be used to excite a symmetric mode, and a high isolation effect can still be generated.

[0161] In addition, as can be seen from the comparison of the isolation effect of the scheme shown in FIG. 11a and the scheme shown in FIG. 6a, by adjusting the length ratio of the first radiating branch 12 and the first radiator 11, the isolation of the first antenna and the third antenna will also be affected.

[0162] In a possible embodiment of the present application, the length L14 of the first radiating branch 12 satisfies: 0.8xn(1 / 2)Xl≤L14≤1.2xn(1 / 2)Xl, where n is an integer greater than or equal to 1, and l is the medium wavelength corresponding to the operating frequency of the first antenna. In this way, the communication requirements of the first radiator 11 can be met, and the first radiating branch 12 can also have the required isolation effect.

[0163] In the above embodiments, the first end portion 121 and the second end portion 122 are oppositely arranged along the direction from the second frame edge 62 to the fourth frame edge 64. However, in actual applications, the specific arrangement positions of the first end portion 121 and the second end portion 122 are not limited. For example, referring to FIGS. 13a and 14a, the first end portion 121 and the second end portion 122 are arranged at current strong points of the first loop structure, respectively. For example, the first end portion 121 is connected to a current strong point of the first antenna, and the second end portion 122 is connected to another current strong point of the first antenna. Alternatively, the first end portion 121 is connected to a current strong point of the third antenna, and the second end portion 122 is connected to another current strong point of the third antenna.

[0164] As can be understood from the above introduction of the design principle of the isolation degree improvement scheme of the antenna system provided in the present application, in actual applications, the radiating branch can be arranged according to the isolation requirements of the antenna system. For example, referring to FIG. 15, which is another structural schematic view of an antenna system of a communication terminal provided in an embodiment of the present application. In this embodiment, the antenna system further includes a third radiating branch 22. In the direction from the second frame edge 62 to the fourth frame edge 64, the projection of the third radiating branch 22 falls within the outline of the projection of the second radiator 21. In the present application, the third radiating branch 22 is similar to the first radiating branch 12 in terms of arrangement. For example, as shown in FIG. 15, the third radiating branch 22 includes a fifth end portion 221 and a sixth end portion 222. The fifth end portion 221 is coupled to the second frame edge 62, and the sixth end portion 222 is coupled to the fourth frame edge 64. The third radiating branch 22 is coupled to the second radiator 21 through the fifth end portion 221 and the sixth end portion 222 to form a closed third loop structure. In addition, the fifth end portion 221 is closer to the third frame edge 63 than the first end portion 121, and the sixth end portion 222 is closer to the third frame edge 63 than the second end portion 122, so that there is no overlapping part between the first radiating branch 12 and the third radiating branch 22.

[0165] It can be understood that the specific arrangement position of the second radiator 21 on the frame can be determined by the positions of the connection points of the fifth end portion 221 and the sixth end portion 222 of the third radiating branch 22 to the frame. That is, the continuous metal structure of the frame between the fifth end portion 221 and the sixth end portion 222 of the third radiating branch 22 and including the third frame edge 63 can be used as the second radiator 21.

[0166] Since the first end 121 and the fifth end 221 are spaced apart, the second end 122 and the sixth end 222 are spaced apart. In actual application, in order to connect the first radiator 11 and the second radiator 21, the first end 121 and the fifth end 221 can be connected, or the second end 122 and the sixth end 222 can be connected, or the first end 121 and the fifth end 221 are connected at the same time, and the second end 122 and the sixth end 222 are also connected.

[0167] Continuing to refer to FIG. 15, the part of the third radiating branch 22 between the fifth end 221 and the sixth end 222 is bent towards the third frame edge 63. In the direction from the first frame edge 61 to the third frame edge 63, the projection length of the third radiating branch 22 on the second frame edge 62 is L21, and the length L21 and the circumference L2 of the third annular structure satisfy: L21≥(1 / 16)×L2. In this way, more current generated by the second antenna 21 working can be bound in the area between the line connecting the fifth end 221 and the sixth end 222 to the third frame edge 63, thereby improving the isolation effect.

[0168] In actual application, the length L21 and the circumference L2 of the third annular structure can also satisfy: (1 / 8)×L2≤L21≤(1 / 4)×L2. In this way, by increasing the bending degree of the third radiating branch 22 towards the third frame edge 63, the distance between the third radiating branch 22 and the third frame edge 63 can be reduced, thereby further improving the binding effect of the current generated by the second antenna working, which is beneficial to improving the isolation between the first antenna and the second antenna.

[0169] In addition, the minimum distance L221 from the part of the third radiating branch 22 bent towards the third frame edge to the second frame edge 62 satisfies: L221≥(1 / 20)×λ. Similarly, the minimum distance L222 from the part of the third radiating branch 22 bent towards the third frame edge to the fourth frame edge 64 satisfies: L222≥(1 / 20)×λ. Wherein, λ is the medium wavelength corresponding to the working frequency of the second antenna. In this way, the third radiating branch 22 can play an effective isolation effect, thereby ensuring the isolation between the first antenna and the second antenna.

[0170] In the present application, the circumference L2 of the third annular structure satisfies: (n+1)×λ×0.8<L2<(n+1)×λ×1.2, wherein n is an integer greater than or equal to 1, and λ is the medium wavelength corresponding to the working frequency of the second antenna. In this way, the communication stability of the antenna system can be improved while meeting the communication requirements of the second antenna.

[0171] It is worth mentioning that in the above formula, λ in (n+1) x λ x 0.8 is the dielectric wavelength corresponding to the minimum operating frequency point in the operating frequency range of the second antenna, and λ in (n+1) x λ x 1.2 is the dielectric wavelength corresponding to the maximum operating frequency point in the operating frequency range of the second antenna.

[0172] Continuing to refer to FIG. 15, the fourth port of the radio frequency chip is coupled with the second radiator 21 through the fourth feeding point 24 to form a fourth antenna, so that the second port of the radio frequency chip can feed the radio frequency signal of the operating frequency range of the second antenna to the second radiator 21 through the second feeding point 23, and the fourth port of the radio frequency chip can feed the radio frequency signal of the operating frequency range of the fourth antenna to the second radiator 21 through the fourth feeding point 24.

[0173] It is worth mentioning that in the present application, the operating frequency range of the second antenna and the operating frequency range of the fourth antenna can both cover the first frequency range, which can be, for example, the 2.4GHz Wi-Fi frequency range or the 5GHz Wi-Fi frequency range.

[0174] In addition, as introduced above, the operating frequency range of the first antenna and the operating frequency range of the second antenna also cover the first frequency range. Therefore, in the embodiments of the present application, the operating frequency ranges of the first antenna, the second antenna, the third antenna and the fourth antenna can cover at least one same frequency range, which can be, for example, the 2.4GHz Wi-Fi frequency range or the 5GHz Wi-Fi frequency range. Then the antenna system provided by the present application can include at least four same frequency antennas, which can work simultaneously or non-simultaneously, and the isolation between the antennas can be ensured through specific design of the feeding points and the radiating branches.

[0175] Exemplarily, similar to the setting mode of the first annular structure, in the embodiment shown in FIG. 15, the second feeding point 23 is arranged at the third frame edge 63, and the fourth feeding point 24 is arranged at the fourth frame edge 64. In a possible embodiment, the distance d1 from the second feeding point 23 to the midpoint of the third frame edge 63 satisfies: 0≤d1≤(1 / 4) x L333, and the distance L23 from the fourth feeding point 24 to the second feeding point 23 satisfies: (1 / 8) x L1≤L23≤(3 / 2) x L1. So that the second antenna and the fourth antenna are more likely to excite the resonance mode.

[0176] In addition, the isolation can also be adjusted by adjusting the distance between the second feeding point 23 and the fourth feeding point 24. In a specific implementation, the length L23 of the portion between the second feeding point 23 and the fourth feeding point 24 along the circumference of the third annular structure satisfies (2n)×(1 / 4)×λ≤L23≤(2n+1)×(1 / 2)×λ, and an example is (2n+1)×(1 / 8)×λ≤L23≤(2n+1)×(3 / 8)×λ, where n is an integer greater than or equal to 0, and λ is the wavelength of the operating frequency of the second antenna in the medium. In this way, the second antenna and the fourth antenna can be excited to a set of resonant modes, for example, the second antenna and the fourth antenna can be excited to a set of orthogonal modes at a suitable position, thereby improving the isolation of the second antenna and the fourth antenna.

[0177] It is worth mentioning that there are many ways to enable the second antenna and the fourth antenna to be excited to a set of orthogonal modes. For example, the second antenna can be used to excite a symmetric mode, and the fourth antenna can be used to excite an anti-symmetric mode, or the second antenna and the fourth antenna can be used to excite other possible modes, respectively. In this way, the isolation of the second antenna and the fourth antenna can be improved.

[0178] In addition, in a possible embodiment of the present application, when the excitation mode of the second antenna and the fourth antenna is capacitive excitation, the second feeding point 23 can be located at the electric field zero point of the fourth antenna, and the fourth feeding point 24 can be located at the electric field zero point of the second antenna. When the excitation mode of the second antenna and the fourth antenna is inductive excitation, the second feeding point 23 can be located at the current zero point of the fourth antenna, and the fourth feeding point 24 can be located at the current zero point of the second antenna. In this way, the third radiating branch 22 can satisfy the required isolation effect while meeting the communication requirements of the second radiator 21.

[0179] In the above embodiment, the second feeding point 23 is arranged on the third frame edge 63, and the fourth feeding point 24 is arranged on the fourth frame edge 64. The arrangement of the two feeding points affects the isolation effect. In other possible embodiments, the fourth feeding point 24 can be arranged on the second frame edge 62, or at least one of the second feeding point 23 and the fourth feeding point 24 can be arranged on the third radiating branch 22. The distance between the two feeding points can be adjusted to enable the second antenna and the fourth antenna to be excited to a set of orthogonal modes at a suitable position, thereby meeting the isolation requirement of the second antenna and the fourth antenna.

[0180] In addition, similar to the introduction of the first annular structure above, in the present application, the isolation effect can also be adjusted by adjusting the ratio of the length of the third radiation branch 22 to the length of the second radiator 21. In one possible embodiment of the present application, the length L22 of the third radiation branch 22 satisfies: 0.8xn(1 / 2)λ≤L22≤1.2xn(1 / 2)λ, where n is an integer greater than or equal to 1, and λ is the medium wavelength corresponding to the operating frequency of the second antenna. In this way, the communication requirements of the second antenna can be met while ensuring that the third radiation branch 22 can achieve the required isolation effect.

[0181] In the present application, the isolation effect can also be adjusted by adjusting the positions of the fifth end portion 221 and the sixth end portion 222. For example, in one possible embodiment, the fifth end portion 221 and the sixth end portion 222 are respectively arranged at a current strong point of the third annular structure, for example, the fifth end portion 221 is electrically connected to a current strong point of the second antenna, and the sixth end portion 222 is electrically connected to another current strong point of the second antenna; or, the fifth end portion 221 is electrically connected to a current strong point of the fourth antenna, and the sixth end portion 222 is electrically connected to another current strong point of the fourth antenna. In this way, the third radiation branch 22 can confine most of the currents generated by the operation of the second antenna and the fourth antenna to the side of the line connecting the fifth end portion 221 and the sixth end portion 222 close to the third frame edge 63, and significantly reduce the current transmitted to the side of the first frame edge 61, thereby achieving the purpose of improving the isolation.

[0182] It is worth mentioning that, since the isolation effect achieved by the specific arrangement of the parts in the third annular structure is similar to the introduction of the first annular structure above, it will not be described here.

[0183] Figure 16 is the S-parameter curve of the conventional antenna system without the first radiation branch and the third radiation branch and the antenna system shown in Figure 15. In Figure 16, case 1 represents the conventional antenna system, and case 2 represents the antenna system shown in Figure 15. As can be seen from Figure 16, compared with the conventional scheme, the design scheme provided in the present application can improve the isolation of the first antenna and the second antenna from -2dB to -25dB, because the first radiation branch 12 can confine most of the currents generated by the operation of the first antenna and the third antenna to the side of the line connecting the first end portion 121 and the second end portion 122 close to the first frame edge 61, and significantly reduce the current transmitted to the side of the third frame edge 63; at the same time, the third radiation branch 22 can confine most of the currents generated by the operation of the second antenna and the fourth antenna to the side of the line connecting the fifth end portion 221 and the sixth end portion 222 close to the third frame edge 63, and significantly reduce the current transmitted to the side of the first frame edge 61, thereby achieving the purpose of improving the isolation.

[0184] To further improve the isolation of the antenna system, the radiation branch can be continuously increased in the antenna system. For example, referring to FIG. 17, which is another schematic diagram of the antenna system of the communication terminal according to an embodiment of the present application. In this embodiment, the antenna system further includes a second radiation branch 31, the projection of the second radiation branch 31 falls within the contour of the projection of the first radiator along the direction from the second frame edge 62 to the fourth frame edge 64. In the present application, the second radiation branch 31 is similar to the first radiation branch 12 in terms of the arrangement, and simply speaking, the second radiation branch 31 includes a third end portion 311 and a fourth end portion 312, the third end portion 311 is coupled to the second frame edge 62, and the fourth end portion 312 is coupled to the fourth frame edge 64, the third end portion 311 is close to the third frame edge 63 relative to the first end portion 121, and the fourth end portion 312 is close to the third frame edge 63 relative to the second end portion 122.

[0185] In addition, it is worth mentioning that when the antenna system includes the first radiation branch 12, the third radiation branch 22 and the second radiation branch 31, the third end portion 311 is located between the first end portion 121 and the fifth end portion 221, and the fourth end portion 312 is located between the second end portion 122 and the sixth end portion 222, so that there is no overlapping part between the first radiation branch 12, the third radiation branch 22 and the second radiation branch 31.

[0186] Continuing to refer to FIG. 17, the second radiation branch 31 is connected to the first radiator 11 through the third end portion 311 and the fourth end portion 312 to form a third loop structure, and the part of the second radiation branch 31 between the third end portion 311 and the fourth end portion 312 is bent towards the first frame edge 61.

[0187] In a possible embodiment of the present application, the length L14 of the second radiation branch 31 satisfies L14=n×(1 / 4)×λ, where n is an integer greater than or equal to 1, and λ is the medium wavelength corresponding to the working frequency of the first radiator 11. In this way, the communication requirements of the first radiator 11 can be met, and the second radiation branch 31 can also have the required isolation effect.

[0188] FIG. 18 is a S-parameter curve diagram of the antenna system shown in FIG. 17 and FIG. 15. In FIG. 18, case 1 represents the antenna system shown in FIG. 15, and case 2 represents the antenna system shown in FIG. 17. By comparison, it can be seen that the antenna system shown in FIG. 17 can further improve the isolation of the antenna system by adding the second radiation branch 31.

[0189] In some possible embodiments of the present application, the antenna system can further improve the isolation by further increasing the radiation branches. FIG. 19 is another structural schematic diagram of an antenna system of a communication terminal according to an embodiment of the present application. In the embodiment shown in FIG. 19, the antenna system further includes a fourth radiation branch 41, which is similar to the third radiation branch 22 in the arrangement manner. In brief, the fourth radiation branch 41 includes a seventh end portion 411 and an eighth end portion 412, the seventh end portion 411 is located between the first end portion 121 and the fifth end portion 221, and the eighth end portion 412 is located between the second end portion 122 and the sixth end portion 222. In addition, in the embodiment shown in FIG. 19, the seventh end portion 411 is also located between the third end portion 311 and the fifth end portion 221, and the eighth end portion 412 is also located between the fourth end portion 312 and the sixth end portion 222, that is, there is no overlap between each radiation branch in the antenna system.

[0190] Continuing to refer to FIG. 19, the fourth radiation branch 41 is connected with the second radiation body 21 through the seventh end portion 411 and the eighth end portion 412 to form a closed fourth loop structure, and the portion of the fourth radiation branch 41 between the seventh end portion 411 and the eighth end portion 412 is bent towards the third frame edge 63.

[0191] In a possible embodiment of the present application, the length L24 of the fourth radiation branch 41 satisfies: n x (1 / 8) x λ ≤ L24 ≤ n x (3 / 8) x λ, where n is an integer greater than or equal to 1, and λ is the medium wavelength corresponding to the working frequency of the second antenna. In this way, the communication requirements of the second antenna can be met while ensuring that the fourth radiation branch 41 can achieve the required isolation effect.

[0192] It can be understood that the design scheme of the antenna system shown in FIG. 19 can further improve the isolation of the antenna system.

[0193] In a possible embodiment of the present application, the bezel can be arranged around the floor 51. In addition, considering that the current generated by the antennas in the antenna system can also be transmitted through the floor 51, the transmission path of the current can also be blocked by opening slots on the floor 51. In implementation, referring to FIG. 20, which is another structural schematic diagram of the antenna system provided by an embodiment of the present application. Compared with the antenna system shown in FIG. 15, in FIG. 20, the floor 51 further includes two slots, namely a first slot 511 and a second slot 512, and the first slot 511 and the second slot 512 are both located between the first radiator and the second radiator 21 along the direction from the first frame edge 61 to the third frame edge 63. In addition, the first slot 511 extends in the direction towards the first frame edge 61, and the second slot 512 extends in the direction towards the third frame edge 63, and the first slot 511 and the second slot 512 do not overlap.

[0194] In addition, in a possible embodiment of the present application, the slot on the floor 51 is also located between the first radiation branch 12 and the third radiation branch 22. In this way, the slot on the floor and each radiation branch jointly block the transmission path of the current, thereby improving the isolation of the antenna system.

[0195] FIG. 21 is an S parameter curve of the antenna system shown in FIG. 15 and FIG. 20. In FIG. 21, case 1 represents the antenna system shown in FIG. 15, and case 2 represents the antenna system shown in FIG. 20. It can be seen through comparison that, by arranging the slots on the floor 51, the isolation between the first antenna and the second antenna can be significantly improved, thereby further improving the isolation of the entire antenna system.

[0196] It can be understood that, in the present application, the length of the slot on the floor 51 can be adjusted to adjust the isolation of the antenna system. In a possible embodiment of the present application, the length L3 of the slot can satisfy: n×(1 / 8)×λ≤L3≤n×(3 / 8)×λ, where n is an integer greater than or equal to 1, and λ is the dielectric wavelength corresponding to the operating frequency of the first antenna or the second antenna.

[0197] In the present application, the length of the slot can be understood as the straight line length of the slot after being straightened along the connecting direction of the two ends of the slot. It is worth mentioning that, FIG. 20 only exemplarily shows one possible arrangement of the slot on the floor 51, and in other embodiments of the present application, the slot on the floor 51 can also be arranged in other possible manners, which are not limited in the present application. In addition, the number of the slot on the floor 51 can also be set to one or more according to the communication requirements in actual application scenarios.

[0198] Fig. 22 is another structural schematic diagram of an antenna system of a communication terminal according to an embodiment of the present application. In this embodiment, the antenna system is provided with a first radiating branch 12, a third radiating branch 22, and a fourth radiating branch 41, and the ground plate 51 is provided with a first slot 511 and a second slot 512. In addition, it is worth mentioning that, in the embodiment shown in Fig. 22, the portion of the first radiating branch 12 that is bent towards the first frame edge 61 is in a serpentine shape, the portion of the third radiating branch 22 that is bent towards the third frame edge 63 is in a serpentine shape, and the portion of the fourth radiating branch 41 that is bent towards the third frame edge 63 is in a C shape.

[0199] Fig. 23 is an S curve of the first antenna, the second antenna, the third antenna, and the fourth antenna of the antenna system shown in Fig. 22. As shown in Fig. 23, the isolation between each antenna is high. This is because, in this antenna system, the first antenna and the third antenna can excite a set of orthogonal modes, and the second antenna and the fourth antenna can excite another set of orthogonal modes, so that, along the direction from the first frame edge 61 to the third frame edge 63, the current can be confined on both sides of the frame, respectively; meanwhile, the slots on the ground plate 51 can block the transmission path of the current.

[0200] In addition, by bending the first radiating branch 12 into a serpentine shape, the miniaturization design of the first radiating branch 12 can be realized while meeting the isolation requirement of the first antenna and the third antenna, thereby facilitating the reduction of the space occupied by the first radiating branch 12 in the communication device. Similarly, by bending the third radiating branch 22 into a serpentine shape, the miniaturization design of the third radiating branch 22 can be realized while meeting the isolation requirement of the second antenna and the fourth antenna, thereby facilitating the reduction of the space occupied by the third radiating branch 22 in the communication device.

[0201] Fig. 24 is another structural schematic diagram of an antenna system of a communication terminal according to an embodiment of the present application. Different from the embodiment shown in Fig. 15, the antenna system shown in Fig. 24 further includes a third radiating body 71 and a fourth radiating body 81, the third radiating body 71 is arranged on the fourth frame edge 64, the fourth radiating body 81 is arranged on the second frame edge 62, and the first radiating body 11, the third radiating body 71, the second radiating body 21, and the fourth radiating body 81 are connected into a closed integrated structure. In addition, the fifth port of the radio frequency chip is coupled with the third radiating body 71 through a fifth feeding point 72 to form a fifth antenna, and the sixth port of the radio frequency chip is coupled with the fourth radiating body 81 through a sixth feeding point 82 to form a sixth antenna. The working frequency range of the first antenna, the working frequency range of the second antenna, the working frequency range of the fifth antenna, and the working frequency range of the sixth antenna all cover a first frequency range, which may, for example, be a 2.4 GHz Wi-Fi frequency range or a 5 GHz Wi-Fi frequency range.

[0202] Fig. 25a is a plot of the isolation between the fifth antenna and the other antennas in the antenna system of Fig. 24. Fig. 25b is a plot of the isolation between the sixth antenna and the other antennas in the antenna system of Fig. 24. As can be seen, the fifth and sixth antennas have high isolation from the other antennas.

[0203] This is because, with the design of the antenna system provided in the present application, the first loop structure formed by the first radiator 11 and the first radiating branch 12 can confine most of the current generated by the first radiator 11 to the side of the two end connections of the first radiating branch 12 facing the first frame edge 61, and the second loop structure formed by the second radiator 21 and the third radiating branch 22 can confine most of the current generated by the second radiator 21 to the side of the two end connections of the third radiating branch 22 facing the third frame edge 63. At the same time, the modes excited by the fifth and sixth antennas can confine the current generated by them between the two loop structures.

[0204] In a possible embodiment of the present application, the fifth and sixth antennas can be used to excite a set of orthogonal modes. For example, the fifth antenna can be used to excite a symmetric mode, and the sixth antenna can be used to excite an anti-symmetric mode, or the fifth antenna can be used to excite an anti-symmetric mode, and the sixth antenna can be used to excite a symmetric mode. In this way, the isolation of the antenna system can be effectively improved.

[0205] The above embodiments are only some exemplary descriptions of the specific configuration of the antenna system provided in the present application. Based on the design principle, the specific configuration of the antenna system can be adjusted adaptively according to the communication requirements in the actual application scenario. For example, the antenna system can include one or more of the first radiating branch 12, the third radiating branch 22, the second radiating branch 31, the fourth radiating branch 41, and the slits, or each radiating branch can be bent into a C shape, a snake shape, or other possible shapes, or the number of antennas in the antenna system can be adjusted. Here, various possible configurations of the antenna system are not listed one by one, but they should all be understood to fall within the scope of protection of the present application.

[0206] As described above, the scheme for improving the isolation of the antenna system provided in the present application is not only applicable to the completely closed metal frame, but also applicable to the non-closed frame including the opening. Fig. 26 is a structural schematic diagram of an antenna system of an antenna box in practical application provided in an embodiment of the present application. It can be referred to Figs. 2 and 26 together. Since the antenna box 700 and the display 800 are communicatively connected through the connecting components such as the circuit board, an opening 702 can be arranged on the side of the antenna box 700 facing the display 800 for avoiding the connecting components such as the circuit board. Therefore, in the antenna box 700 shown in Fig. 26, the frame is a non-closed frame. In addition, it can be understood that the other three connected surfaces of the frame of the antenna box 700 shown in Fig. 26 can all be used as the radiator for realizing the communication function.

[0207] The other structures of the antenna box shown in Fig. 26 can be arranged according to any of the above embodiments, which will not be described herein.

[0208] In addition, based on the design principle of the antenna system provided in the present application, the antenna box can also be designed in appearance according to specific design requirements in practical application.

[0209] It can be understood that when one frame edge of the frame of the communication terminal includes an opening, for example, the second frame edge 62 includes the opening 702, the opening 702 is located between the first radiator 11 and the second radiator 21. In addition, the antenna system can further include a third radiator 71 arranged on the fourth frame edge 64, and a fifth port of the radio frequency chip is coupled with the third radiator 71 through a fifth feeding point to form a fifth antenna, the first radiator 11, the third radiator 71 and the second radiator 21 are connected in sequence, and the working frequency range of the first antenna, the working frequency range of the second antenna and the working frequency range of the fifth antenna all cover the first frequency range, for example, the first frequency range can be 2.4 GHz Wi-Fi frequency range or 5 GHz Wi-Fi frequency range. Among them, the first radiator 11, the second radiator 21 and the third radiator 71 can all be arranged according to any of the above embodiments, which can make the antenna system have a structure including five same-frequency antennas. In this structure, the current can be bound by the first radiating branch 12 and the third radiating branch 22, so that the isolation between the antennas meets the communication requirements.

[0210] The scheme for improving the isolation of the antenna system provided in the present application is not only applicable to the fixed communication terminal such as the antenna box, but also applicable to various communication terminals having the four-surface metal structure. For example, it can be used in mobile terminals such as mobile phones. Figs. 27a to 27d show several possible arrangement modes of the above antenna system in the mobile terminal, which are similar to the arrangement modes of the antenna systems in the above embodiments and the isolation effects that can be achieved, which will not be described herein.

[0211] The above merely provides the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A communication terminal, characterized by comprising: The communication terminal comprises a frame and an antenna system, the frame is arranged around the circumference of the communication terminal, the frame comprises a first frame edge, a second frame edge, a third frame edge and a fourth frame edge connected in sequence, the first frame edge is arranged opposite to the third frame edge, and the second frame edge is arranged opposite to the fourth frame edge; the antenna system comprises a first radiator, a second radiator, a first radiation branch and a radio frequency chip, wherein: the first radiator is arranged on the first frame edge, the second frame edge and the fourth frame edge, at least part of the second radiator is arranged on the second frame edge, the third frame edge or the fourth frame edge; the first radiator and the second radiator are connected; the first radiation branch comprises a first end and a second end, the first end is coupled with the second frame edge, the second end is coupled with the fourth frame edge, the first radiation branch is coupled with the first radiator through the first end and the second end to form a first annular structure, and part of the first radiation branch between the first end and the second end is bent towards the first frame edge; a first port of the radio frequency chip is coupled with the first radiator through a first feeding point to form a first antenna, a second port of the radio frequency chip is coupled with the second radiator through a second feeding point to form a second antenna, and the working frequency range of the first antenna and the working frequency range of the second antenna both cover a first frequency range.

2. The communication terminal of claim 1, wherein, In the direction from the first frame edge to the third frame edge, the projection length of the first radiation branch on the second frame edge is L11; the length L11 and the circumference L1 of the first annular structure satisfy: L11≥(1 / 16)×L1.

3. The communication terminal of claim 2, wherein, The length L11 and the circumference L1 of the first annular structure satisfy: (1 / 8)×L1≤L11≤(1 / 4)×L1.

4. The communication terminal according to claim 2 or 3, characterized by The circumference L1 of the first annular structure satisfies: (n+1)×λ×0.8<L1<(n+1)×λ×1.2, wherein n is an integer greater than or equal to 1, and λ is the dielectric wavelength corresponding to the working frequency of the first antenna.

5. The communication terminal according to any one of claims 1 to 4, characterized by The minimum distance L12 from the part of the first radiation branch bent towards the first frame edge to the second frame edge satisfies: L12≥(1 / 20)×λ; the minimum distance L13 from the part of the first radiation branch bent towards the first frame edge to the fourth frame edge satisfies: L13≥(1 / 20)×λ, wherein λ is the dielectric wavelength corresponding to the working frequency of the first antenna.

6. The communication terminal according to any one of claims 1 to 5, characterized by The length L14 of the first radiation branch satisfies: 0.8×n×(1 / 2)×λ≤L14≤1.2×n×(1 / 2)×λ, wherein n is an integer greater than or equal to 1, and λ is the dielectric wavelength corresponding to the working frequency of the first antenna.

7. The communication terminal according to any one of claims 1 to 6, characterized by A third port of the radio frequency chip is coupled with the first radiator through a third feeding point to form a third antenna, and the working frequency range of the third antenna and the working frequency range of the first antenna both cover the first frequency range. The length L15 of the portion between the first feeding point and the third feeding point along the circumference of the first loop structure satisfies (2n)×(1 / 4)×λ≤L15≤(2n+1)×(1 / 2)×λ, where n is an integer greater than or equal to 0, and λ is a dielectric wavelength corresponding to the operating frequency of the first antenna.

8. The communication terminal of claim 7, wherein, The first feeding point is arranged at the first frame edge, and the third feeding point is arranged at the second frame edge.

9. The communication terminal of claim 8, wherein, The distance d between the first feeding point and the midpoint of the first frame edge satisfies 0≤d≤(1 / 4)×L111, and the distance L15 between the third feeding point and the first feeding point satisfies (1 / 8)×L1≤L15≤(3 / 2)×L1.

10. The communication terminal according to claim 8 or 9, characterized by When the first antenna and the third antenna are excited in a capacitive manner, the first feeding point is located at an electric field zero point of the third antenna, and the third feeding point is located at an electric field zero point of the first antenna; when the first antenna and the third antenna are excited in an inductive manner, the first feeding point is located at a current zero point of the third antenna, and the third feeding point is located at a current zero point of the first antenna.

11. The communication terminal of claim 10, wherein, The first end portion is connected to one current strong point of the first antenna, and the second end portion is connected to another current strong point of the first antenna; or the first end portion is connected to one current strong point of the third antenna, and the second end portion is connected to another current strong point of the third antenna.

12. The communication terminal according to any one of claims 1 to 11, characterized by The portion of the first radiating branch that is bent towards the first frame edge is bent in a C shape or a serpentine shape.

13. The communication terminal according to any one of claims 1 to 12, characterized by The antenna system further comprises a second radiating branch, a projection of the second radiating branch falls within the contour range of the projection of the first radiator along the direction from the second frame edge to the fourth frame edge; the second radiating branch comprises a third end portion and a fourth end portion, the third end portion is coupled to the second frame edge, and the fourth end portion is coupled to the fourth frame edge, the third end portion is closer to the third frame edge than the first end portion, and the fourth end portion is closer to the third frame edge than the second end portion. The second radiating branch is coupled to the first radiator through the third end portion and the fourth end portion to form a closed second loop structure, and a portion of the second radiating branch between the third end portion and the fourth end portion is bent towards the first frame edge.

14. The communication terminal of claim 13, wherein, The length L16 of the second radiating branch satisfies n×(1 / 8)×λ≤L16≤n×(3 / 8)×λ, where n is an integer greater than or equal to 1, and λ is a dielectric wavelength corresponding to the operating frequency of the first antenna.

15. The communication terminal according to any one of claims 1 to 14, characterized by The antenna system further comprises a third radiation branch, a projection of the third radiation branch falls within a contour range of the projection of the second radiator in a direction from the second frame edge to the fourth frame edge; the third radiation branch comprises a fifth end and a sixth end, the fifth end is coupled with the second frame edge, the sixth end is coupled with the fourth frame edge, the fifth end is close to the third frame edge relative to the first end, and the sixth end is close to the third frame edge relative to the second end; the third radiation branch and the second radiator are coupled to form a closed third annular structure, and a part of the third radiation branch between the fifth end and the sixth end is bent towards the third frame edge.

16. The communication terminal of claim 15, wherein, The fourth port of the radio frequency chip is coupled with the second radiator through a fourth feeding point to form a fourth antenna, and operating frequency bands of the second antenna and the fourth antenna both cover the first frequency band. In a contour line of the third annular structure, a length L23 of a part between the second feeding point and the fourth feeding point satisfies (2n)×(1 / 4)×λ≤L23≤(2n+1)×(1 / 2)×λ, where n is an integer greater than or equal to 0, and λ is a medium wavelength corresponding to an operating frequency of the second antenna.

17. The communication terminal according to claim 15 or 16, characterized by The antenna system further comprises a fourth radiation branch, a projection of the fourth radiation branch falls within a contour range of the projection of the second radiator in a direction from the second frame edge to the fourth frame edge; the fourth radiation branch comprises a seventh end and an eighth end, the seventh end is connected with the second frame edge, the eighth end is connected with the fourth frame edge, the seventh end is between the first end and the third end, and the eighth end is between the second end and the fourth end; The fourth radiation branch is coupled with the second radiator through the seventh end and the eighth end to form a closed fourth annular structure, and a part of the fourth radiation branch between the seventh end and the eighth end is bent towards the third frame edge.

18. The communication terminal according to any one of claims 15 to 17, characterized by The antenna system further comprises a third radiator and a fourth radiator, the third radiator is arranged at the fourth frame edge, and the fourth radiator is arranged at the second frame edge; the first radiator, the third radiator, the second radiator and the fourth radiator are connected into a closed integrated structure. A fifth port of the radio frequency chip is coupled with the third radiator through a fifth feeding point to form a fifth antenna, and a sixth port of the radio frequency chip is coupled with the fourth radiator through a sixth feeding point to form a sixth antenna; operating frequency bands of the first antenna, the second antenna, the fifth antenna and the sixth antenna all cover the first frequency band.

19. The communication terminal according to any one of claims 15 to 17, characterized by The second frame edge comprises an opening, the opening is between the first radiator and the second radiator; the antenna system further comprises a third radiator, the third radiator is arranged at the fourth frame edge, and the first radiator, the third radiator and the second radiator are connected in sequence. The fifth port of the radio frequency chip is coupled with the third radiator through a fifth feeding point to form a fifth antenna, and the operating frequency range of the first antenna, the operating frequency range of the second antenna and the operating frequency range of the fifth antenna all cover the first frequency range.

20. The communication terminal according to any one of claims 1 to 19, characterized by The communication terminal further comprises a housing and a floor, the bezel is arranged on the housing, the floor is arranged on or in the housing, and the bezel is arranged around the floor. The floor comprises at least one slit, and the at least one slit is located between the first radiator and the second radiator in the direction from the first frame edge to the third frame edge.

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