Communication terminal

Abstract

The invention provides a communication terminal, an antenna system of the communication terminal comprises a frame and an antenna system, and the frame is arranged in the circumferential direction of the communication terminal. The antenna system comprises a radio frequency chip, at least two radiators arranged on the frame and a radiation branch knot, and the at least two radiators are connected. The radio frequency chip is respectively coupled with the at least two radiators through different feeding points to form at least two antennas, and the working frequency bands of the at least two antennas cover the first frequency band. The radiation branch knot is coupled with one radiation body to form an annular structure, and the radiation branch knot is bent towards the radiation body. In the communication terminal, the annular structure can be used for restricting the current generated by the antenna to flow to the other antenna, so that the isolation between at least two antennas with the same frequency can be improved, and the communication capability of the communication terminal can be improved. Due to the adoption of the scheme, the frame can be effectively prevented from being slotted, so that the structural strength, the appearance attractiveness and the consistency of the communication terminal can be improved.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a communication terminal. Background Technology

[0002] With the rapid development of communication technology and the widespread use of smartphones, people's demands for communication terminals are increasing. In particular, the requirements for the communication capabilities of communication terminals are also rising. The communication capabilities of a communication terminal are achieved through its antenna system; therefore, improving the performance of the antenna system in communication terminals is an important development direction in this field.

[0003] Currently, communication terminal antenna systems typically include multiple antennas. These antennas may operate simultaneously or asynchronously. Furthermore, the operating frequency bands of these antennas may cover at least one common frequency band, or they may operate in different frequency bands. For multiple antennas operating simultaneously and covering at least one common frequency band, isolation is a significant challenge. However, existing solutions for improving isolation often sacrifice antenna system performance in certain application scenarios, or are only suitable for improving the isolation of a single frequency band or a small number of radiators. In short, they cannot meet the isolation requirements of communication terminal antenna systems. Summary of the Invention

[0004] The communication terminal provided in this application includes an antenna system, and the communication capability of the communication terminal is improved by improving the isolation of the antenna system.

[0005] This application provides a communication terminal, which includes a frame and an antenna system. The frame is arranged circumferentially around the communication terminal and includes a first frame edge, a second frame edge, a third frame edge, and a fourth frame edge connected sequentially. The first frame edge and the third frame edge are arranged opposite each other, and the second frame edge and the fourth frame edge are arranged opposite each other. The antenna system includes a first radiator, a second radiator, a first radiating stub, and a radio frequency chip. The first radiator is disposed on the first frame edge, the second frame edge, and the fourth frame edge, and the second radiator is disposed on the second frame edge, the third frame edge, or the fourth frame edge. The first radiator and the second radiator are connected. In a specific arrangement of the first radiating stub, it includes a first end and a second end. The first end is coupled to the second frame edge, and the second end is coupled to the fourth frame edge. The first radiating stub is coupled to the first radiator through the first end and the second end to form a first ring structure, and the portion of the first radiating stub located between the first end and the second end bends toward the first frame edge. A first port of the radio frequency chip is coupled to a first radiator through a first feed point to form a first antenna, and a second port of the radio frequency chip is coupled to a second radiator through a second feed point to form a second antenna. The operating frequency bands of both the first and second antennas cover the first frequency band. In the communication terminal provided in this application, since the operating frequency bands of both the first and second radiators cover the first frequency band, the antenna system includes at least two antennas operating at the same frequency. Furthermore, in this antenna system, the first radiating stub and the first radiator form the aforementioned first ring structure, thereby confining most of the current generated by the first antenna to the area between the connection between the first and second ends and the first frame edge. This effectively improves the isolation between the first and second antennas, which is beneficial for enhancing the communication capability of the communication terminal. Moreover, since this solution effectively avoids gaps in the frame, it improves the structural strength, aesthetics, and consistency of the communication terminal.

[0006] In one possible implementation of this application, the projection length of the first radiating branch on the second frame edge along the direction from the first frame edge to the third frame edge is L11, and this length L11 satisfies the following relationship with the perimeter L1 of the first ring structure: L11 ≥ (1 / 16) × L1. This can improve the confinement effect on the current generated by the operation of the first antenna, thereby improving the isolation of the antenna system.

[0007] Furthermore, in practical applications, the aforementioned length L11 can be made to satisfy the following relationship with the perimeter L1 of the first annular structure: (1 / 8)×L1≤L11≤(1 / 4)×L1. This increases the bending degree of the first radiating stub towards the first frame edge, thereby reducing the distance between the first radiating stub and the first frame edge. This further enhances the confinement effect on the current generated by the first antenna, which is beneficial for improving the isolation between the first and second antennas.

[0008] When specifically setting up the first ring structure, the perimeter L1 of the first ring structure satisfies: (n+1)×λ×0.8<L1<(n+1)×λ×1.2, where n is an integer greater than or equal to 1, and λ is the wavelength of the medium corresponding to the operating frequency of the first antenna. This satisfies the radiation requirements of the antenna mode in which the first antenna operates.

[0009] In one possible embodiment of this application, the minimum distance L12 from the portion of the first radiating stub that bends towards the first frame edge to the second frame edge satisfies: L12 ≥ (1 / 20) × λ. Similarly, the minimum distance L13 from the portion of the first radiating stub that bends towards the first frame edge to the fourth frame edge satisfies: L13 ≥ (1 / 20) × λ. Wherein, λ is the dielectric wavelength corresponding to the operating frequency of the first antenna. This ensures that the first radiating stub can provide effective isolation, thereby guaranteeing the isolation between the first antenna and the second antenna.

[0010] Furthermore, in this application, the length L14 of the first radiating stub satisfies: 0.8×n×(1 / 2)×λ≤L14≤1.2×n×(1 / 2)×λ, where n is an integer greater than or equal to 1, and λ is the wavelength of the medium corresponding to the operating frequency of the first antenna. This ensures that the first radiating stub provides adequate isolation while meeting the communication requirements of the first antenna.

[0011] In the communication terminal provided in this application, the third port of the radio frequency chip is coupled to the first radiator through a third feed point to form a third antenna. The operating frequency band of the third antenna and the operating frequency band of the first antenna both cover the first frequency band. Furthermore, along the circumference of the first annular structure, the length L15 between the first feed point and the third feed point 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 the dielectric wavelength corresponding to the operating frequency of the first antenna. This allows the first and third antennas to be excited to generate a set of resonant modes, thereby improving the isolation between the first and third antennas.

[0012] In one possible implementation of this application, when setting the positions of the first feed point and the third feed point, the first feed point can be set on the first frame edge, and the third feed point can be set on the second frame edge. This makes the distance between the first feed point and the third feed point smaller, so as to facilitate the excitation of the resonant mode.

[0013] Furthermore, the distance d from the first feed point to the midpoint of the first frame edge satisfies the following relationship with the length L111 of the first frame edge: 0 ≤ d ≤ (1 / 4) × L111; the distance L15 from the third feed point to the first feed point satisfies the following relationship: (1 / 8) × L1 ≤ L15 ≤ (3 / 2) × L1. This is to make it easier for the first and third antennas to excite the resonant mode.

[0014] In one possible implementation of this application, when the first and third antennas are capacitively excited, the first feed point is located at the electric field zero of the third antenna, and the third feed point is located at the electric field zero of the first antenna. When the first and third antennas are inductively excited, the first feed point is located at the current zero of the third antenna, and the third feed point is located at the current zero of the first antenna. This ensures that the communication requirements of the first antenna are met while also guaranteeing that the first radiating stub provides the required isolation.

[0015] In this application, the isolation level can also be adjusted by setting the position of the first radiating stub. For example, in one possible implementation, the first end of the first radiating stub is connected to a high-current point of the first antenna, and the second end is connected to another high-current point of the first antenna. Alternatively, the first end can be connected to a high-current point of the third antenna, and the second end can be connected to another high-current point of the third antenna. This can improve the isolation effect of the first radiating stub.

[0016] As described above, in this application, a set of resonant modes can be excited by the first antenna and the third antenna to improve the isolation between them. Based on this, in one possible implementation, the first antenna and the third antenna can be used to excite a set of orthogonal modes. This can help produce a high isolation effect, thereby improving the isolation between the first antenna and the third antenna.

[0017] In practical applications, the first antenna can be used to excite a symmetrical mode, and the third antenna can be used to excite an antisymmetric mode. Alternatively, the first antenna can be used to excite an antisymmetric mode, and the third antenna can be used to excite a symmetrical mode. This allows the first and third antennas to excite a set of orthogonal modes, thereby producing a high isolation effect.

[0018] As mentioned above, the first radiating stub is a bent structure. In one possible implementation of this application, the portion of the first radiating stub that bends towards the first frame edge can be C-shaped or serpentine. This allows for miniaturization of the first radiating stub while ensuring the isolation requirements of the first and third antennas are met, thereby reducing the space occupied by the first radiating stub within the communication equipment. In other implementations, the first radiating stub can also have other bending forms, which are not limited in this application.

[0019] To further improve the isolation effect of the antenna system, in one possible implementation of this application, the antenna system further includes a second radiating stub. Along the direction from the second frame edge to the fourth frame edge, the projection of the second radiating stub falls within the projection outline of the first radiator. The second radiating stub includes a third end and a fourth end. The third end is coupled to the second frame edge, and the fourth end is coupled to the fourth frame edge. The third end is closer to the third frame edge relative to the first end, and the fourth end is closer to the third frame edge relative to the second end, so that the second radiating stub and the first radiating stub do not overlap. Furthermore, the second radiating stub forms a closed third ring structure with the first radiator through its third and fourth ends, and the portions of the second radiating stub located at the third and fourth ends bend towards the first frame edge. This arrangement of the first and third ring structures improves the isolation of the antenna system.

[0020] When specifically configuring the second radiating stub, its 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 wavelength of the medium corresponding to the operating frequency of the first antenna. This ensures that the second radiating stub provides adequate isolation while meeting the communication requirements of the first antenna.

[0021] In one possible implementation of this application, the antenna system further includes a third radiating stub. Along the direction from the second frame edge to the fourth frame edge, the projection of the third radiating stub falls within the outline of the projection of the second radiator. The third radiating stub includes a fifth end and a sixth end. The fifth end is coupled to the second frame edge, and the sixth end is coupled to the fourth frame edge. The fifth end is closer to the third frame edge than the first end, and the sixth end is closer to the third frame edge than the second end, so that the third radiating stub does not overlap with the first radiating stub. Furthermore, the third radiating stub connects with the second radiator to form a closed third ring structure, and the portion of the third radiating stub located between the fifth and sixth ends bends towards the third frame edge. This effectively improves the isolation between the first and second antennas by confining the current generated by the first antenna through the first radiating stub and confining the current generated by the second antenna through the third radiating stub, thereby enhancing the communication capability of the communication terminal.

[0022] When specifically setting 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. This length L21 satisfies the following relationship with the circumference L2 of the third ring structure: L21 ≥ (1 / 16) × L2. This can confine more of the current generated by the second antenna operation within the area between the connection between the fifth and sixth ends and the third frame edge, thereby improving the isolation effect.

[0023] In this application, the perimeter L2 of the second ring structure satisfies: (n+1)×λ×0.8<L2<(n+1)×λ×1.2, where n is an integer greater than or equal to 1, and λ is the dielectric wavelength corresponding to the operating frequency of the second antenna. This satisfies the radiation requirements of the antenna mode for the second antenna operation.

[0024] Furthermore, the length L22 of the third radiating stub satisfies: 0.8×n×(1 / 2)×λ≤L22≤1.2×n×(1 / 2)×λ, where n is an integer greater than or equal to 1, and λ is the wavelength of the medium corresponding to the operating frequency of the second antenna. This ensures that the third radiating stub provides adequate isolation while meeting the communication requirements of the second antenna.

[0025] In the communication terminal provided in this application, the fourth port of the radio frequency chip is coupled to the second radiator through the fourth feed point to form a fourth antenna. Along the contour line of the third ring structure, the length L23 of the portion between the second feed point and the fourth feed 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 the dielectric wavelength corresponding to the operating frequency of the second antenna. This allows for the excitation of a set of resonant modes by the third and fourth antennas, thereby improving the isolation between the third and fourth antennas.

[0026] Furthermore, when setting the positions of the second and fourth feed points, the second feed point can be placed on the third frame edge, and the fourth feed point can be placed on either the second or fourth frame edge. Additionally, when the second and fourth antennas are excited capacitively, the second feed point is located at the electric field zero point of the fourth antenna, and the fourth feed point is located at the electric field zero point of the second antenna. Conversely, when the second and fourth antennas are excited capacitively, the second feed point is located at the current zero point of the fourth antenna, and the fourth feed point is located at the current zero point of the second antenna. This ensures that the third radiating stub provides the required isolation while meeting the communication requirements of the second radiator.

[0027] In this application, the isolation can also be adjusted by setting the position of the third radiating stub. For example, in one possible implementation, the fifth end of the third radiating stub is connected to a high-current point of the second antenna, and the sixth end is connected to another high-current point of the second antenna. Alternatively, the fifth end is connected to a high-current point of the fourth antenna, and the sixth end is connected to another high-current point of the fourth antenna. This can improve the isolation effect between the second and fourth antennas.

[0028] As described above, in this application, the isolation between the second and fourth antennas can be improved by exciting a set of resonant modes. Based on this, in one possible implementation, the second and fourth antennas can be used to excite a set of orthogonal modes. This can help produce a high isolation effect, thereby improving the isolation between the second and fourth antennas.

[0029] In practical applications, the second antenna can be used to excite symmetric modes, and the fourth antenna can be used to excite antisymmetric modes. Alternatively, the second antenna can be used to excite antisymmetric modes, and the fourth antenna can be used to excite symmetric modes. This allows the second and fourth antennas to excite a set of orthogonal modes, thereby producing a high isolation effect.

[0030] To further improve the isolation effect of the antenna system, in one possible implementation of this application, the antenna system further includes a fourth radiating stub. Along the direction from the second frame edge to the fourth frame edge, the projection of the fourth radiating stub falls within the outline of the projection of the second radiator. The fourth radiating stub includes a seventh end and an eighth end. The seventh end is connected to the second frame edge, and the eighth end is connected to the fourth frame edge. The seventh end is located between the first end and the third end, and the eighth end is located between the second end and the fourth end, so that the fourth radiating stub does not overlap with either the first or second radiating stub. Furthermore, the fourth radiating stub couples with the second radiator through the seventh and eighth ends to form a closed fourth ring structure, and the portion of the fourth radiating stub located between the seventh and eighth ends bends towards the third frame edge. This effectively improves the isolation between the first and second antennas, thereby enhancing the communication capability of the communication terminal.

[0031] When specifically configuring the fourth radiating stub, its length L24 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 wavelength of the medium corresponding to the operating frequency of the second antenna. This ensures that the fourth radiating stub provides adequate isolation while meeting the communication requirements of the second antenna.

[0032] In one possible implementation of this application, the antenna system further includes a third radiator and a fourth radiator. The third radiator is disposed on the fourth frame edge, and the fourth radiator is disposed on the second frame edge. The first, third, second, and fourth radiators are connected to form a closed, integrated structure. Additionally, the fifth port of the RF chip is coupled to the third radiator through a fifth feed point to form a fifth antenna, and the sixth port of the RF chip is coupled to the fourth radiator through a sixth feed point to form a sixth antenna. The operating frequency bands of the first, second, third, and fourth antennas all cover the first frequency band. The antenna isolation design provided in this application can also achieve good isolation when applied to antenna systems including multiple antennas operating at the same frequency, thereby ensuring the communication performance of the communication terminal.

[0033] In the communication terminal provided in this application, the fifth and sixth antennas can be used to excite a set of orthogonal modes. This creates a high isolation effect between the fifth and sixth antennas and other antennas, thereby improving the isolation of the antenna system.

[0034] In practical applications, the fifth antenna can be used to excite a symmetric mode, and the sixth antenna can be used to excite an antisymmetric mode. Alternatively, the fifth antenna can be used to excite an antisymmetric mode, and the sixth antenna can be used to excite a symmetric mode. This allows the fifth and sixth antennas to excite a set of orthogonal modes, thereby producing a high isolation effect.

[0035] The proposed solution for improving the isolation of an antenna system is applicable not only to completely enclosed metal frames but also to non-enclosed frames including openings. For example, in one possible implementation, the second frame edge includes an opening located between the first and second radiators. Furthermore, the antenna system includes a third radiator disposed on a fourth frame edge, with the first, third, and second radiators sequentially connected. The operating frequency bands of the first, second, and third antennas all cover the first frequency band. This still achieves a high level of isolation between the antennas, thereby improving the communication performance of the communication terminal.

[0036] Based on the design principles of the antenna system provided in this application, isolation can be further improved by adding other structures capable of blocking the flow of current. For example, in one possible implementation, the communication terminal further includes a housing and a floor, with a frame disposed on the housing and the floor disposed on or inside the housing, and the frame surrounding the floor. Based on this, the floor can include at least one slot along the direction from the first frame edge to the third frame edge, and this at least one slot is located between the first radiator and the second radiator. This allows the slot on the floor to block the transmission path of the current generated by each antenna, thereby improving the isolation between the antennas of the antenna system.

[0037] In this application, the length L3 of the floor slit 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 dielectric wavelength corresponding to the operating frequency of the first or second antenna. This ensures that the floor slit provides adequate isolation while meeting the communication requirements of each antenna. Attached Figure Description

[0038] Figure 1 A schematic diagram of the structure of a communication terminal provided in an embodiment of this application;

[0039] Figure 2 Another structural schematic diagram of the communication terminal provided in the embodiments of this application;

[0040] Figure 3 A schematic diagram of the structure of an antenna box provided in an embodiment of this application;

[0041] Figure 4 A schematic diagram of the antenna system of a communication terminal provided in an embodiment of this application;

[0042] Figure 5 Another schematic diagram of the antenna system of the communication terminal provided in the embodiments of this application;

[0043] Figure 6a and Figure 6b This application provides a schematic diagram of two first ring structures with the first and third feed points located at different positions.

[0044] Figure 7 for Figure 6a and Figure 6b The S-parameter curves of the first and third antennas in the structure shown;

[0045] Figure 8a A schematic diagram of the excitation mode of the first antenna of the antenna system provided in an embodiment of this application;

[0046] Figure 8b Demonstrated as Figure 8a The electric field distribution excited by the first antenna is shown.

[0047] Figure 9a A schematic diagram of the excitation mode of the third antenna of the antenna system provided in the embodiments of this application;

[0048] Figure 9b Demonstrated as Figure 9a The electric field distribution excited by the third antenna is shown.

[0049] Figure 10 A schematic diagram of an LC series resonant circuit provided in an embodiment of this application;

[0050] Figure 11a This is another schematic diagram of the first annular structure provided in the embodiments of this application;

[0051] Figure 11b This is another schematic diagram of the first annular structure provided in the embodiments of this application;

[0052] Figure 12 for Figure 11a and Figure 11b The S-parameter curves of the first and third antennas in the structure shown;

[0053] Figure 13a A schematic diagram of the excitation mode of the first antenna of the antenna system provided in an embodiment of this application;

[0054] Figure 13b Demonstrated as Figure 13a , 13b The electric field distribution excited by the first antenna is shown.

[0055] Figure 14a A schematic diagram of the excitation mode of the third antenna of the antenna system provided in the embodiments of this application;

[0056] Figure 14b Demonstrated as Figure 14a The electric field distribution excited by the third antenna is shown.

[0057] Figure 15 Another schematic diagram of the antenna system of the communication terminal provided in the embodiments of this application;

[0058] Figure 16 For traditional antenna systems without first and second radiating stubs and Figure 15 The S-parameter curves of the antenna system are shown below;

[0059] Figure 17 Another schematic diagram of the antenna system of the communication terminal provided in the embodiments of this application;

[0060] Figure 18 for Figure 17 and Figure 15 The S-parameter curves of the antenna system are shown below.

[0061] Figure 19 Another schematic diagram of the antenna system of the communication terminal provided in the embodiments of this application;

[0062] Figure 20 This is another schematic diagram of the antenna system provided in the embodiments of this application;

[0063] Figure 21 for Figure 15and Figure 20 The S-parameter curve of the antenna system described above;

[0064] Figure 22 Another schematic diagram of the antenna system of the communication terminal provided in the embodiments of this application;

[0065] Figure 23 for Figure 22 The S-curves of the first, second, third, and fourth antennas of the antenna system shown;

[0066] Figure 24 Another schematic diagram of the antenna system of the communication terminal provided in the embodiments of this application;

[0067] Figure 25a for Figure 24 The isolation curves between the fifth antenna and the other antennas in the antenna system shown.

[0068] Figure 25b for Figure 24 The isolation curves between the sixth antenna and the other antennas in the antenna system shown.

[0069] Figure 26 A schematic diagram of an antenna system for an antenna box in a practical application provided by an embodiment of this application;

[0070] Figures 27a to 27d Several possible configuration methods of the antenna system provided in the embodiments of this application in a mobile terminal.

[0071] Figure label:

[0072] 100 - Cover plate; 200 - Display screen / module; 300 - Printed circuit board; 400 - Middle frame; 500 - Back cover; 600 - Frame; 61 - First frame edge;

[0073] 62 - Second frame edge; 63 - Third frame edge; 64 - Fourth frame edge;

[0074] 700 - Antenna box; 701 - Four-sided metal frame; 702 - Opening; 800 - Display;

[0075] 11-First radiator; 12-First radiating branch; 121-First end; 122-Second end; 13-First feed point; 14-Third feed point;

[0076] 21-Second radiator; 22-Third radiating branch; 221-Fifth end; 222-Sixth end; 23-Second feed point; 24-Fourth feed point;

[0077] 31-Second radial branch; 311-Third end; 312-Fourth end;

[0078] 41-Fourth radial branch; 411-Seventh terminal; 412-Eighth terminal;

[0079] 51-Floor; 511-First seam; 512-Second seam;

[0080] 71 - Third radiator; 72 - Fifth feed point; 81 - Fourth radiator; 82 - Sixth feed point. Detailed Implementation

[0081] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings. However, the exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein. The same reference numerals in the figures denote the same or similar structures, and therefore repeated descriptions of them will be omitted. The terms expressing position and direction described in the embodiments of this application are illustrative based on the accompanying drawings, but changes can be made as needed, and all such changes are included within the scope of protection of this application. The accompanying drawings of the embodiments of this application are only for illustrating relative positional relationships and do not represent actual scale.

[0082] It should be noted that specific details are set forth in the following description to facilitate understanding of this application. However, the embodiments of this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the embodiments of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0083] The following explains the terminology that may appear in the embodiments of this application.

[0084] Radiator: In an antenna, this is the device used to receive / transmit electromagnetic wave radiation. In some cases, the term "antenna" is narrowly defined as a radiator, which converts guided wave energy from the 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 radiator via a feed line, where it is converted into electromagnetic wave energy of a specific polarization and radiated in the desired direction. The receiving radiator converts the electromagnetic wave energy of a specific polarization from a specific direction in space back into modulated high-frequency current energy, which is then transmitted to the receiver input via a feed line.

[0085] The radio frequency (RF) chip is the combination of all components of an antenna used for receiving and transmitting radio frequency waves. In the case of a receiving antenna, the RF chip can be considered as the antenna section from the first amplifier to the front-end transmitter. In a transmitting antenna, the RF chip can be seen as the section after the last power amplifier. In some cases, the RF chip can also be understood as the feed unit. The RF chip has the function of converting radio waves into electrical signals and sending them to the receiver components. Generally, it is considered as part of the antenna system 3, used for converting radio waves into electrical signals and vice versa. Maximum power transfer capability and efficiency should be considered when designing an antenna. For this purpose, the antenna feed impedance must be matched with the load resistance. The antenna feed impedance is a combination of resistance, capacitance, and inductance. To ensure maximum power transfer conditions, the two impedances (load resistance and feed impedance) should be matched. Matching can be achieved by considering frequency requirements and antenna design parameters (e.g., gain, directivity, and radiation efficiency).

[0086] Feed line: Also called a transmission line, it refers to the connection line between the antenna's radio frequency chip and the radiator. Depending on the frequency and form, the transmission line can directly transmit current waves or electromagnetic waves. The connection point on the radiator where it connects to the transmission line is usually called the feed point. Transmission lines include conductive transmission lines, coaxial transmission lines, waveguides, or microstrip lines. Depending on the implementation, transmission lines can include bracket antenna bodies or glass antenna bodies. Depending on the carrier, transmission lines can be implemented using LCP (Liquid Crystal Polymer), FPC (Flexible Printed Circuit), or PCB (Printed Circuit Board), etc.

[0087] Communication / Operating Frequency Band: Regardless of the type of antenna, it always operates within a certain frequency range (bandwidth). For example, an antenna supporting the B40 band operates within the frequency range of 2300MHz to 2400MHz, or in other words, its operating frequency band includes the B40 band. The frequency range that meets the specifications can be considered the antenna's operating frequency band. The width of the operating frequency band is called the operating bandwidth. The operating bandwidth of an omnidirectional antenna may reach 3-5% of the center frequency. The operating bandwidth of a directional antenna may reach 5-10% of the center frequency. Bandwidth can be considered as a frequency range on both sides of the center frequency (e.g., the resonant frequency of a dipole), where the antenna characteristics are within the acceptable range of the center frequency.

[0088] The resonant frequency band and the operating frequency band can be the same or different, or their frequency ranges can partially overlap. In one embodiment, the resonant frequency band of the antenna can cover multiple operating frequency bands of the antenna.

[0089] Medium wavelength: refers to the wavelength of electromagnetic waves propagating in a medium at the operating frequency band. For example, if the operating frequency band is [f1, f2], the corresponding medium wavelength is also the range [w1, w2]. Alternatively, to simplify calculations, the above-mentioned medium wavelength can also refer to the wavelength of electromagnetic waves propagating in the medium at the center frequency f0 of the operating frequency band. In this case, the medium wavelength is a specific value w0.

[0090] Antenna return loss: This can be understood as the ratio of the signal power reflected back to the antenna port after passing through the antenna circuit to the transmit power at the antenna port. The smaller the reflected signal, the larger the signal radiated into space through the antenna, and the higher the antenna's radiation efficiency. Conversely, the larger the reflected signal, the smaller the signal radiated into space through the antenna, and the lower the antenna's radiation efficiency.

[0091] Antenna return loss can be represented by the S11 parameter, which is one of the S-parameters. S11 represents the reflection coefficient, and this parameter characterizes the antenna's transmission efficiency.

[0092] In one embodiment, the S11 diagram can be understood as a schematic diagram representing the resonance generated by the antenna. In one embodiment, the resonance shown in the S11 diagram within the range of -6dB can be understood as the resonant frequency / frequency range / operating frequency band generated by the antenna. The S11 parameter is usually negative. The smaller the S11 parameter, the smaller the antenna return loss, the less energy reflected back by the antenna itself, which means more energy actually enters the antenna, and the higher the antenna radiation efficiency; the larger the S11 parameter, the greater the antenna return loss, and the lower the antenna radiation efficiency.

[0093] It should be noted that in engineering, an S11 value of -6dB is generally used as the standard. When the S11 value of an antenna is less than -6dB, the antenna can be considered to be working normally, or the antenna can be considered to have good transmission efficiency.

[0094] Radiation efficiency refers to the ratio of the power radiated by an antenna into space (i.e., the power effectively converted into electromagnetic waves) to the active power input to the antenna. The active power input to the antenna equals the antenna's input power minus the power loss. Power loss mainly includes return loss power, ohmic loss power of the metal, and / or dielectric loss power. Both metal loss and dielectric loss are factors affecting radiation efficiency.

[0095] Those skilled in the art will understand that radiation efficiency is generally expressed as a percentage, and there is a corresponding conversion relationship between it and dB. The closer the radiation efficiency is to 0 dB, the better the radiation efficiency of the antenna.

[0096] dB: This stands for decibel, a logarithmic concept with base 10. Decibels are used to evaluate the proportional relationship between two physical quantities; they themselves have no physical dimensions. For every 10-fold increase in the ratio between two quantities, their difference can be expressed as 10 decibels. For example: A = 100, B = 10, C = 5, D = 1, then A / D = 20 dB; B / D = 10 dB; C / D = 7 dB; B / C = 3 dB. In other words, a 10-decibel difference between two quantities is a 10-fold difference, a 20-decibel difference is a 100-fold difference, and so on. A 3-decibel difference is a 2-fold difference between the two quantities.

[0097] The term "end" in the context of the main radiator's first / second / third / fourth / grounded / open ends should not be narrowly interpreted as a point or end physically disconnected from other radiators. It can also refer to a segment of the main radiator including the first endpoint, which is the endpoint of the main radiator at the gap. For example, the first end of the main radiator can be considered a segment of the main radiator within a range of one-eighth of a first wavelength from the first endpoint. The first wavelength can be the wavelength corresponding to the operating frequency band of the main radiator, the wavelength corresponding to the center frequency of the operating frequency band, or the wavelength corresponding to the resonant point. In one embodiment, "end / point" can include a connection / coupling region on the radiator that is coupled to other conductive structures. For example, a feed end / feed point can be a coupling region on the antenna radiator that is coupled to a feed structure (e.g., a region facing a part of the feed structure). Similarly, a ground end / grounding point can be a connection / coupling region on the antenna radiator that is coupled to a ground structure.

[0098] Open and Closed Terminals: In some embodiments, open and closed terminals are defined relative to whether or not they are grounded; the closed terminal is grounded, and the open terminal is not grounded. In one embodiment, the open terminal may also be referred to as a floating terminal, a free terminal, an open terminal, or an open-circuit terminal. In one embodiment, the closed terminal may also be referred to as a grounded terminal or a short-circuit terminal. It should be understood that in some embodiments, other conductors can be coupled through the open terminal to transfer coupled energy (which can be understood as transferring current).

[0099] In some embodiments, the open end and the closed end are, for example, relative to other conductors, with the closed end electrically connected to other conductors and the open end not electrically connected to other conductors.

[0100] To put it simply, the "open end" of a radiator can be defined as one end of the radiator that is spaced apart from the floor or coupled to the floor through a capacitive device.

[0101] To put it simply, the "grounding terminal" of a radiator can be understood as: if one end of the radiator is directly connected to the floor or coupled to the floor through an inductive device, it can be regarded as the grounding terminal of the radiator.

[0102] In some embodiments, the understanding of "closed end" can also be from the perspective of current distribution. A closed end or ground end can be understood as a point of high current or low electric field on a radiator. In one embodiment, coupling electronic devices (e.g., inductive devices) through a closed end can maintain the current distribution characteristics of the point of high current / low electric field. In one embodiment, opening a gap at or near the closed end (e.g., filling the gap with insulating material) can maintain the current distribution characteristics of the point of high current / low electric field.

[0103] In some embodiments, the understanding of "open terminal" can also be from the perspective of current distribution. An open terminal or a floating terminal can be understood as a point with a small current or a point with a large electric field on the radiator. In one embodiment, coupling electronic devices (e.g., capacitive devices) through an open terminal can maintain the current distribution characteristics of the point with a small current or a large electric field.

[0104] It should be understood that when an electronic device (e.g., capacitor, inductor, etc.) is coupled at the radiator end of a gap (which, from the perspective of the radiator's structure, resembles a radiator at the opening of an open or suspended end), the radiator end can be a point with a large current / small electric field. In this case, it should be understood that the radiator end at the gap is actually a closed end or a grounded end, etc.

[0105] Capacitance: can be understood as lumped capacitance and / or distributed capacitance. Lumped capacitance includes capacitive components, such as capacitor elements; distributed capacitance (or distributed capacitance) includes the equivalent capacitance formed by two conductive components separated by a certain gap.

[0106] Electrical length: Electrical length can be expressed as the ratio of physical length (i.e., mechanical length or geometric length) multiplied by the time it takes for an electrical or electromagnetic signal to travel in a medium to the time required for that signal to travel a distance in free space equal to the physical length of the medium. Electrical length can be expressed by the following formula:

[0107]

[0108] Where L is the physical length, a is the transmission time of the electrical or electromagnetic signal in the medium, and b is the transmission time in free space.

[0109] Alternatively, electrical length can also refer to the ratio of physical length (i.e., mechanical length or geometric length) to the wavelength of the transmitted electromagnetic wave, and electrical length can satisfy the following formula:

[0110]

[0111] Where L is the physical length and λ is the wavelength of the electromagnetic wave.

[0112] In some embodiments of this 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%.

[0113] In the embodiments of this application, the wavelength in a certain wavelength mode of the antenna (such as half-wavelength mode, etc.) 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, where 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, where ε is the relative permittivity of the medium, and the frequency is the frequency of the radiated signal.

[0114] To facilitate understanding of the communication terminal provided in this application embodiment, its application scenario is first introduced below. The communication terminal in this application embodiment refers to a terminal with communication functions. Specifically, it can refer to a communication terminal employing 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 this application embodiment can include a mobile terminal or a fixed terminal. For example, a mobile terminal can be a mobile phone, tablet computer, laptop computer, smart bracelet, smartwatch, smart helmet, and smart glasses; a fixed terminal can be a router, smart TV, smart home device, smart speaker, and desktop computer. In addition, the aforementioned communication terminal may also be a handheld device with wireless communication function, a computing device or other processing device 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 this application are not limited to this.

[0115] first, Figure 1An exemplary embodiment of a communication terminal provided in this application is illustrated, with a mobile terminal such as a mobile phone as an example for explanation. Figure 1 As shown, in one embodiment, the communication terminal includes a cover 100, a display / module 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 may be a glass cover, or it may be replaced with a cover made of other materials, such as an ultra-thin glass cover, a polyethylene terephthalate (PET) cover, etc. In one embodiment, the cover 100, the middle frame 400, and the rear cover 500 can all be considered as part of the housing.

[0116] The cover plate 100 can be set close to the display screen 200, and can be mainly used to protect the display screen 200 from dust.

[0117] In one embodiment, the display screen 200 may include a liquid crystal display (LCD), a light emitting diode (LED) display panel, or an organic light-emitting diode (OLED) display panel, etc., and this application does not limit it.

[0118] The 400mm mid-frame primarily serves to support the entire machine. Figure 1 The diagram shows PCB 300 positioned between the mid-frame 400 and the back cover 500. It should be understood that in one embodiment, PCB 300 may also be positioned between the mid-frame 400 and the display screen 200; this application does not impose any limitations on this. PCB 300 may be made of flame-retardant material (FR-4) dielectric substrate, Rogers dielectric substrate, or a hybrid dielectric substrate of Rogers and FR-4, etc. Here, FR-4 is a designation for a flame-retardant material grade, and Rogers dielectric substrate is a high-frequency board. Electronic components, such as radio frequency chips, are mounted on PCB 300.

[0119] In one embodiment, a metal layer may be disposed on the PCB 300. This metal layer can be used for grounding electronic components carried on the PCB 300, or for grounding other components, such as bracket antennas, frame antennas, etc. This metal layer may be referred to as a ground plane, grounding plate, or grounding layer. In one embodiment, this metal layer can be formed by etching metal onto the surface of any dielectric substrate in the PCB 300. In one embodiment, the grounding metal layer may be disposed on the side of the PCB 300 near the middle frame 400. In one embodiment, the edge of the PCB 300 can be considered as the edge of its grounding layer. In one embodiment, the metal middle frame 400 may also be used for grounding the aforementioned components. The communication terminal may also have other ground planes / grounding plates, as previously described, and will not be repeated here.

[0120] The communication terminal may also include a battery (not shown in the figure). The battery may be located between the middle frame 400 and the back cover 500, or between the middle frame 400 and the display screen 200; this application does not impose any limitations on this. In some embodiments, the PCB 300 is divided into a motherboard and a daughterboard, and the battery may be located between the motherboard and the daughterboard. Specifically, the motherboard may be located between the middle frame 400 and the upper edge of the battery, and the daughterboard may be located between the middle frame 400 and the lower edge of the battery.

[0121] The communication terminal may also include a frame 600, which may be formed of a conductive material such as metal. The frame 600 may be disposed between the display screen 200 and the back cover 500 and extend circumferentially around the periphery of the communication terminal. The frame 600 may have four sides surrounding the display screen 200 to help secure the display screen 200. In one implementation, the frame 600 made of metal can be directly used as the metal frame of the communication terminal, forming a metal frame appearance suitable for industrial design (ID). In another implementation, the outer surface of the frame 600 may also be made of a non-metallic material, such as a plastic frame, forming a non-metallic frame appearance suitable for non-metallic ID.

[0122] The middle frame 400 may include a border 600. The middle frame 400, including the border 600, is a single unit that supports the electronic components in the device. The cover plate 100 and the rear cover 500 respectively cover the upper and lower edges of the border to form the outer shell or housing of the communication terminal. Alternatively, the border 600 may not be considered part of the middle frame 400. In one embodiment, the border 600 may be connected to the middle frame 400 and integrally formed. In another embodiment, the border 600 may include an inwardly extending protrusion to connect with the middle frame 400, for example, by means of spring clips, screws, welding, etc. In one embodiment, the cover plate 100, the rear cover 500, the border 600, and the middle frame 400 may be collectively referred to as the outer shell or housing of the communication terminal. It should be understood that "outer shell or housing" can be used to refer to part or all of any one of the cover plate 100, rear cover 500, frame 600 or middle frame 400, or to part or all of any combination of the cover plate 100, rear cover 500, frame 600 or middle frame 400.

[0123] The back cover 500 can be made of metal; it can also be made of non-conductive materials, such as glass or plastic; or it can be made of both conductive and non-conductive materials.

[0124] In one embodiment, the frame 600 can at least partially function as a radiator to receive / transmit radio frequency signals. This portion of the frame acting as a radiator may have gaps between itself and other parts of the middle frame 400, or between itself and the middle frame 400, thereby ensuring a good radiation environment for the radiator. In one embodiment, an aperture may be provided near this portion of the frame acting as a radiator. In one embodiment, the aperture may include an aperture located inside the communication terminal, for example, an aperture not visible from the exterior of the communication terminal. In one embodiment, the internal aperture may be formed by any one or more of the middle frame 400, battery, circuit board, back cover 500, display screen 200, and other internal conductive components; for example, the internal aperture may be formed by a structural component of the middle frame 400. In one embodiment, the aperture may also include a slot / slit / opening on the frame 600. In one embodiment, the slot / slit / opening on the frame 600 may be a slit formed on the frame 600, at which the frame 600 is divided into two parts without a direct connection. In one embodiment, the aperture may further include a slit / gap / aperture provided on the back cover 500 or the display screen 200. In one embodiment, the back cover 500 includes a conductive material, and the aperture provided in the conductive material may communicate with a slit or gap in the frame 600 to form a continuous aperture on the surface of the communication terminal.

[0125] In one embodiment, the radiator of the communication terminal may also be disposed within the frame 600. The frame 600 comprises a non-conductive material, and the radiator of the antenna may be located within the communication terminal and disposed along the frame 600, or the radiator may be at least partially embedded within the non-conductive material of the frame. In one embodiment, the radiator is disposed close to the non-conductive material of the frame 600 to minimize the volume occupied by the radiator and to be closer to the outside of the communication terminal, thereby achieving better signal transmission performance. It should be noted that "disposed close to the frame 600" means that the radiator can be disposed tightly against the frame 600 or close to the frame 600, for example, there may be a small gap between the radiator and the frame 600.

[0126] In one embodiment, the radiator of the communication terminal may also be disposed within the housing, such as a bracket antenna, etc. Figure 1 (Not shown in the image). A gap may exist between the radiator located within the housing and other conductive components inside the housing to ensure a good radiation environment for the radiator. In one embodiment, an aperture may be provided near the radiator. In one embodiment, the aperture may include an aperture located inside the communication terminal, for example, an aperture not visible from the exterior of the communication terminal. In one embodiment, the internal aperture may be formed by any one or multiple of the frame 600, middle frame 400, battery, circuit board, back cover 500, display screen 200, and other internal conductive components; for example, the internal aperture may be formed by a structural component of the middle frame 400. In one embodiment, the aperture may also include a slot / slit / opening on the frame 600. In one embodiment, the slot / slit / opening on the frame 600 may be a slit formed on the frame 600, at which the frame 600 is divided into two parts without a direct connection. In one embodiment, the aperture may also include a slot / slit / opening on the back cover 500 or the display screen 200. In one embodiment, the back cover 500 includes a conductive material, and the apertures formed in the conductive material can communicate with the slots or breaks in the frame 600 to form continuous apertures on the surface of the communication terminal. In one embodiment, the apertures on the back cover 500 or the display screen 200 can also be used to house other devices, such as cameras, and / or sensors, and / or microphones, and / or speakers, etc.

[0127] Figure 1 The diagram only schematically illustrates some of the components included in the communication terminal; the actual shape, size, and construction of these components are not subject to change. Figure 1 The limitations. Furthermore. Figure 1 The above only illustrates some possible forms of communication terminals. In other embodiments, the above-mentioned communication terminal may also be a foldable mobile terminal or other terminal device with communication functions.

[0128] in addition, Figure 2 This application provides an exemplary embodiment of another communication terminal, where a fixed terminal such as a smart screen is used as an example for illustration. Figure 2 As shown, in order to realize the communication function, the smart screen usually includes an antenna box 700. The antenna box 700 is exemplarily set at the top center of the display 800, but it can also be set at other positions of the display 800, as long as the communication performance of the antenna in the antenna box 700 can be guaranteed.

[0129] Understandably, compared with the above Figure 1 Compared to the mobile terminal shown, a fixed terminal like a smart screen can be understood as setting up the display 800 and the antenna system separately, and then connecting the two through a circuit board or other electrical connections to achieve communication between the antenna system and the display 800.

[0130] Currently, the antenna box 700 is typically a cuboid structure consisting of four metal frames 701. Figure 3 This is a schematic diagram of an antenna box provided in an embodiment of this application. The four metal frames 701 of the antenna box 700 are similar to those described above. Figure 1 The frame arrangement of the communication terminal shown is similar, meaning that the four-sided metal frame 701 is arranged circumferentially around the antenna box 700. Furthermore, the four-sided metal frame 701 can directly serve as the outer surface of the antenna box 700, forming its metal ID; or it can be at least partially embedded in a non-metallic material, or its outer surface can be made of a non-metallic material, such as plastic. It is worth noting that the outer surface of the four-sided metal frame 701 being a non-metallic material can be understood as the four-sided metal frame 701 being set against the non-metallic outer surface, i.e., the four-sided metal frame 701 is in close contact with the non-metallic outer surface, or there is a certain small gap between the four-sided metal frame 701 and the non-metallic outer surface. Additionally, the four-sided metal frame 701 can be a frame structure with a certain supporting function, or it can be a metal coating located on the inner side of the outer surface of the antenna box 700. Therefore, in this application, the specific arrangement of the four-sided metal frame 701 of the antenna box 700 is not limited.

[0131] Similar to the frame of the mobile terminal described above, at least a portion of the four-sided metal frame 701 of the antenna box 700 can also serve as a radiator to receive / transmit radio frequency signals. Therefore, in this application, the antenna box 700 itself can also be regarded as a communication terminal.

[0132] Furthermore, based on the above description of the four-sided metal frame 701 of the antenna box 700 and the frame of the mobile phone, in the following embodiments of this application, structures similar to the four-sided metal frame 701 in the antenna box 700 and the frame of the mobile phone can be collectively referred to as the frame of the communication terminal. Additionally, regardless of the form of the frame of the communication terminal, it can be either a completely closed structure or a non-closed frame including openings.

[0133] In communication terminals, the antenna system typically includes multiple antennas to achieve communication functions. Whether it's the aforementioned mobile terminal or antenna box, the multiple antennas integrated within may operate simultaneously or not simultaneously. Furthermore, the operating frequency bands of these multiple antennas may cover at least one common frequency band, or the operating frequency bands of the multiple antennas may all be different. Generally, to ensure the communication stability of multiple antennas, a certain degree of isolation is required between the antennas. Understandably, for multiple antennas operating simultaneously, and whose operating frequency bands cover at least one common frequency band, the requirement for isolation is even higher.

[0134] In view of this, the communication terminal provided in this application improves the isolation of the antenna system by setting radiating stubs in the antenna system, thereby enhancing the communication capability of the communication terminal. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0135] Figure 4 This is a schematic diagram of the antenna system of a communication terminal provided in an embodiment of this application. Figure 4 As shown, the frame of the communication terminal includes a first frame edge 61, a second frame edge 62, a third frame edge 63, and a fourth frame edge 64 connected in sequence. The first frame edge 61 and the third frame edge 63 are arranged opposite to each other, and the second frame edge 62 and the fourth frame edge 64 are arranged opposite to each other. It is worth mentioning that, in this application, the frame edge can be not only a line, but also a surface, or a plate with a significant thickness.

[0136] Additionally, the antenna system includes a first radiator 11, a second radiator 21, and a first radiating stub 12. The first radiator 11 is disposed on the first frame edge 61, the second frame edge 62, and the fourth frame edge 64. The second radiator 21 is disposed on the third frame edge 63, the second frame edge 62, or the fourth frame edge 64. Figure 4 In the embodiment shown, the second radiator 21 is simultaneously disposed on the third frame edge 63, the second frame edge 62, and the fourth frame edge 64.

[0137] In this application, the first radiator 11 and the second radiator 21 are connected. Additionally, the antenna system also includes a radio frequency chip (RF chip). Figure 4(Not shown in the image) The first port of the RF chip is coupled to the first radiator 11 through the first feed point 13 to form the first antenna, and the second port of the RF chip is coupled to the second radiator 21 through the second feed point 23 to form the second antenna. The operating frequency bands of the first antenna and the second antenna both cover the first frequency band, which may be, for example, the 2.4GHz Wi-Fi band or the 5GHz Wi-Fi band.

[0138] It is worth noting that this application does not limit the specific configuration of the radio frequency (RF) chip. For example, the RF chip can be a single unit, in which case each port of the RF chip can be used to couple with a corresponding radiator to form different antennas. Alternatively, in this application, the RF chips used for coupling with different radiators are configured separately. In this application, the ports of the RF chips coupled with different radiators refer to the ports of the different RF chips.

[0139] In addition, in this application, the first radiator 11 and the second radiator 21 can be connected through the non-metallic portion of the frame. Alternatively, the first radiator 11 and the second radiator 21 can be connected through the metallic portion of 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 into a single structure. This is beneficial to improving the integrity of the frame and allows the complete metal frame to be used as the radiator of multiple antennas of the same frequency at the same time.

[0140] You can continue to refer to Figure 4 The first radiating branch 12 includes a first end 121 and a second end 122, wherein the first end 121 is coupled to the second frame edge 62, the second end 122 is coupled to the fourth frame edge 64, and the first radiating branch 12 is coupled to the first radiator 11 through the first end 121 and the second end 122 to form a first ring structure.

[0141] In practical applications, the specific location of the first radiator 11 on the frame can be determined by the position of the connection point between the first end 121 and the second end 122 of the first radiating branch 12 and the frame. That is, the continuous metal structure of the frame located between the first end 121 and the second end 122 of the first radiating branch 12, including the first frame edge 61, can serve as the first radiator 11. At least the portion of the frame located between the first end 121 and the second end 122 of the first radiating branch 12, excluding the first radiator 11, can serve as the second radiator 21.

[0142] In addition, such as Figure 4 As shown in the embodiment of this application, the portion of the first radiating branch 12 located between the first end 121 and the second end 122 is bent toward the first frame edge 61, so that the first radiating branch 12 and the first radiator 11 form an approximately U-shaped first annular structure.

[0143] It is understood that by adopting the antenna system solution provided in this application, the length of the first radiator 11, the length of the first radiating stub 12, and the size of the portion of the first radiating stub 12 bent toward the first frame edge 61 can be adjusted so that most of the current generated by the first antenna flows along the first ring structure. This confines most of the current generated by the first antenna to the area between the line connecting the first end 121 and the second end 122 and the first frame edge 61, which helps to improve the isolation between the first antenna and the second antenna, thereby improving the stability of the first antenna and the second antenna when they operate in the same frequency band, and thus improving the communication performance of the communication terminal.

[0144] In addition, as can be seen from the above description of the antenna system provided in this application, since the first radiator 11 and the second radiator 21 are connected, it can effectively avoid gaps in the frame, thereby improving the structural strength, appearance and consistency of the communication terminal.

[0145] You can continue to refer to Figure 4 In this embodiment of the application, along the direction from the first frame edge 61 to the third frame edge 63, that is... Figure 4 In the X direction shown, the projection length of the first radiating branch 12 on the second frame edge 62 is L11. This length L11 satisfies the condition L1≥(1 / 16)×L1 with the circumference L1 of the first ring structure. This can confine more of the current generated by the operation of the first antenna to the area between the line connecting the first end 121 and the second end 122 and the first frame edge 61, thereby improving the isolation effect.

[0146] In practical applications, the aforementioned length L11 and the perimeter L1 of the first annular structure satisfy the following relationship: (1 / 8)×L1≤L11≤(1 / 4)×L1. This allows for an increase in the bending degree of the first radiating stub 12 towards the first frame edge 61, thereby reducing the distance between the first radiating stub 12 and the first frame edge 61. This further enhances the confinement effect on the current generated by the first antenna, which is beneficial for improving the isolation between the first and second antennas.

[0147] Furthermore, in this application, the minimum distance L12 from the portion of the first radiating stub 12 bent towards the first frame edge 61 to the second frame edge 62, that is, along the Y direction, satisfies: L12 ≥ (1 / 20) × λ. Similarly, the minimum distance L13 from the portion of the first radiating stub 12 bent towards the first frame edge 61 to the fourth frame edge 64 satisfies: L13 ≥ (1 / 20) × λ. Wherein, λ is the dielectric wavelength corresponding to the operating frequency of the first antenna. This ensures that the first radiating stub 12 can provide effective isolation, thereby guaranteeing the isolation between the first antenna and the second antenna.

[0148] Since different radio frequency signals can be fed into the first radiator 11 to excite the first antenna to corresponding resonant modes, and different resonant modes have different effects on isolation, in practical applications, the first radiator 11 can be fed according to specific communication requirements. Figure 5 This is another schematic diagram of the antenna system of the communication terminal provided in the embodiments of this application. Figure 5 In the illustrated embodiment, the first port of the RF chip is coupled to the first radiator 11 through the first feed point 13 to form a first antenna. Thus, the first port of the RF chip can feed RF signals within the operating frequency band of the first antenna to the first radiator 11 through the first feed point 13. Furthermore, the third port of the RF chip is coupled to the first radiator 11 through the third feed point 14 to form a third antenna. Thus, the third port of the RF chip can feed RF signals within the operating frequency band of the third antenna to the first radiator 11 through the third feed point 14.

[0149] It is worth mentioning that in this 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 may be, for example, the 2.4GHz Wi-Fi band or the 5GHz Wi-Fi band.

[0150] This application does not limit the specific arrangement of the first feed point 13 and the third feed point 14 on the first ring structure, for example... Figure 5 In the embodiment shown, the first power supply point 13 is located on the first frame edge 61, and the third power supply point 14 is located on the second frame edge 62.

[0151] To illustrate the impact of the placement of the first feed point 13 and the third feed point 14 on the isolation of the antenna system, please refer to [reference needed]. Figure 6a and Figure 6b , Figure 6a and Figure 6b This application provides a schematic diagram of two first ring structures with the first and third feed points located at different positions. A comparison shows that... Figure 6a and Figure 6bIn the embodiments shown, the location of the first feed point 13 is the same, but... Figure 6b The distance between the first feed point 13 and the third feed point 14 in the embodiment shown is greater than 1 / 3. Figure 6a The aforementioned spacing.

[0152] Additionally, refer to Figure 7 , Figure 7 for Figure 6a and Figure 6b The S-parameter curves of the first and third antennas in the structure shown are displayed. Case 1 represents... Figure 6a In the illustrated embodiment, case 2 represents Figure 6b The illustrated embodiment. (By...) Figure 7 It can be seen that, using Figure 6a The design shown can generate a decoupling pit at 2.42 GHz, and the isolation between the first and third antennas can reach -30 dB. And because of... Figure 6b In the design shown, the distance between the first feed point 13 and the third feed point 14 is relatively large, and the isolation between the first antenna and the third antenna deteriorates to -2dB.

[0153] Therefore, it can be understood that the spacing between the first feed point 13 and the third feed point 14 has a significant impact on the isolation of the antenna system. In one possible embodiment of this application, the length L15 of the portion between the first feed point 13 and the third feed point 14 along the circumference of the first annular structure satisfies: (2n)×(1 / 4)×λ≤L15≤(2n+1)×(1 / 2)×λ, for example, (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 dielectric wavelength corresponding to the operating frequency of the first antenna. This allows the first and third antennas to be excited to form a set of resonant modes, thereby improving the isolation between them.

[0154] In the above embodiments, such as Figure 5 As shown, the first feed point 13 can be located on the first frame edge 61, and the third feed point 14 can be located on the second frame edge 62. Furthermore, the distance d from the first feed point 13 to the midpoint of the first frame edge 61 satisfies the following relationship with the length L111 of the first frame edge 61: 0 ≤ d ≤ (1 / 4) × L111. The distance L15 from the third feed point 14 to the first feed point 13 satisfies the following relationship: (1 / 8) × L1 ≤ L15 ≤ (3 / 2) × L1. This is to make it easier for the first and third antennas to excite resonant modes.

[0155] In practical applications, by adjusting the positions of the first feed point 13 and the third feed point 14, as well as the distance between them, the first antenna and the third antenna can be used to excite a set of orthogonal modes at suitable locations. For example, by feeding an radio frequency signal into the first antenna, the first antenna can be used to excite a set of orthogonal modes, such as... Figure 8a The symmetrical pattern shown, in addition, Figure 8b Demonstrated as Figure 8a The electric field distribution excited by the first antenna is shown.

[0156] At the same time, the third antenna can also be used to excite such as Figure 9a The antisymmetric mode shown. Additionally, Figure 9b Demonstrated as Figure 9a The electric field distribution excited by the third antenna is shown.

[0157] From the above Figure 8a and Figure 8b as well as Figure 9a and Figure 9b As can be seen, in this application, by exciting the first antenna in a symmetrical mode and the third antenna in an antisymmetric mode, a high isolation effect can be achieved. This is because the first ring structure formed by connecting the first radiating stub 12 and the first radiator 11 can constitute a structure as follows: Figure 10 The LC series resonant circuit shown can effectively improve the isolation between the first antenna and the third antenna.

[0158] It is worth mentioning that, in one possible embodiment of this application, when the excitation method of the first antenna and the third antenna is capacitive excitation, the first feed point 13 may also be located at the electric field zero point of the third antenna, and the third feed point 14 may be located at the electric field zero point of the first antenna. When the excitation method of the first antenna and the third antenna is inductive excitation, the first feed point 13 may be located at the current zero point of the third antenna, and the third feed point 14 may be located at the current zero point of the first antenna. Thus, while satisfying the communication requirements of the first radiator 11, the first radiating stub 12 can also achieve the required isolation effect.

[0159] In the above embodiments, the example of the first feed point 13 being located on the first frame edge 61 and the third feed point 14 being located on the second frame edge 62 is used to illustrate the impact of the arrangement of the two feed points on the isolation effect. In other possible embodiments, at least one of the first feed point 13 and the third feed point 14 can be located on the first radiating stub 12. The distance between the two feed points can also be adjusted to excite a set of orthogonal modes in the first and third antennas at appropriate positions, thereby meeting the isolation requirements of the first and third antennas.

[0160] In this embodiment, the perimeter L1 of the first ring structure satisfies: (n+1)×λ×0.8<L1<(n+1)×λ×1.2, where n is an integer greater than or equal to 1, and λ is the dielectric wavelength corresponding to the operating frequency band of the first antenna. This satisfies the radiation requirements of the antenna mode of the first antenna and improves the communication stability of the antenna system.

[0161] It is worth mentioning that in the above formula, λ in (n+1)×λ×0.8 is the dielectric wavelength corresponding to the minimum operating frequency point within the operating frequency range of the first antenna, and λ in (n+1)×λ×1.2 is the dielectric wavelength corresponding to the maximum operating frequency point within the operating frequency range of the first antenna.

[0162] It is understandable 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 radiating branch 12. The length of the first radiating branch 12 can be understood as the straight line length of the first radiating branch 12 stretched along the direction from the first end 121 to the second end 122. Therefore, the length of the first radiator 11 is the straight line length of the first radiator 11 stretched along the direction from the first end 121 to the second end 122. Furthermore, when the first radiating branch 12 is coupled to the first radiator 11 through a device or gap, the circumference of the first annular structure remains the length of the complete annular ring.

[0163] In practical applications, the length ratio of the first radiator 11 and the first radiating branch 12 can be adjusted according to specific design requirements. For example, refer to... Figure 11a , Figure 11a This is another schematic diagram of the first annular structure provided in an embodiment of this application. Similar to the above... Figure 6a Compared to the first ring structure shown, in Figure 11a In the process, the ratio of the length of the first radiating branch 12 to the length of the first radiating body 11 decreases.

[0164] in addition, Figure 11b Another schematic diagram of the first annular structure provided in the embodiments of this application is also shown. Figure 11a and Figure 11b In the middle, the positions of the first feed point 13 are the same, but the distance between the first feed point 13 and the third feed point 14 is different.

[0165] Reference Figure 12 , Figure 12 for Figure 11a and Figure 11b The S-parameter curves of the first and third antennas in the structure shown are displayed. Case 1 represents... Figure 11a In the illustrated embodiment, case 2 represents Figure 11b The illustrated embodiment. (By...) Figure 12 It can be seen that, using Figure 11aThe design shown can generate a decoupling pit at 2.42 GHz, and the isolation between the first and third antennas can reach -23 dB. And because of... Figure 11b In the design scheme shown, due to the large distance between the first feed point 13 and the third feed point 14, the isolation between the first antenna and the third antenna deteriorates to -1dB.

[0166] Then by Figure 12 The comparison also shows that by adjusting the distance between the two feed points, the resonant modes that the first and third antennas can be excited can be adjusted, thereby adjusting the isolation between the first and third antennas.

[0167] In practical applications, the first and third antennas can still be used to excite a set of orthogonal modes at appropriate locations. For example, the first antenna can be used to excite... Figure 13a The symmetrical pattern shown, in addition, Figure 13b Demonstrated as Figure 13a The electric field distribution excited by the first antenna is shown. Simultaneously, a third antenna can also be used to excite, such as... Figure 14a The antisymmetric mode shown. Additionally, Figure 14b Demonstrated as Figure 14a The electric field distribution excited by the third antenna is shown.

[0168] From the above Figure 13a and Figure 13b as well as Figure 14a and Figure 14b As can be seen, in this application, by exciting the first antenna in a symmetrical mode and the third antenna in an antisymmetric mode, a high isolation effect can be achieved, which can effectively improve the isolation between the first antenna and the third antenna.

[0169] In the above embodiments, the first antenna is used to excite the symmetric mode and the third antenna is used to excite the antisymmetric mode as examples to illustrate the resulting isolation effect. In other embodiments of this application, the first antenna can also be used to excite the antisymmetric mode and the third antenna can be used to excite the symmetric mode, while still producing a high degree of isolation.

[0170] In addition, through the Figure 11a The scheme shown and Figure 6a The comparison of the isolation effects of the schemes shown shows that adjusting the length ratio of the first radiating stub 12 and the first radiator 11 will also affect the isolation between the first antenna and the third antenna.

[0171] In one possible embodiment of this application, the length L14 of the first radiating stub 12 satisfies: 0.8×n×(1 / 2)×λ≤L14≤1.2×n×(1 / 2)×λ, where n is an integer greater than or equal to 1, and λ is the wavelength of the medium corresponding to the operating frequency of the first antenna. This ensures that the first radiating stub 12 provides the required isolation while meeting the communication requirements of the first radiator 11.

[0172] In the above embodiments, the first end 121 and the second end 122 are arranged opposite each other along the direction from the second frame edge 62 to the fourth frame edge 64 as examples. However, in actual applications, the specific positions of the first end 121 and the second end 122 are not limited. For example, please continue to refer to... Figure 13a and Figure 14a The first end 121 and the second end 122 are respectively disposed at a strong current point of the first ring structure. For example, the first end 121 is connected to a strong current point of the first antenna, and the second end 122 is connected to another strong current point of the first antenna; or the first end 121 is connected to a strong current point of the third antenna, and the second end 122 is connected to another strong current point of the third antenna.

[0173] As can be understood from the above description of the design principle of the antenna system isolation improvement scheme provided in this application, in practical applications, radiating stubs can be set according to the isolation requirements of the antenna system. For example, refer to... Figure 15 , Figure 15 This is another schematic diagram of the antenna system of the communication terminal provided in an embodiment of this application. In this embodiment, the antenna system further includes a third radiating stub 22, and the projection of the third radiating stub 22 falls within the outline of the projection of the second radiator 21 along the direction from the second frame edge 62 to the fourth frame edge 64. In this application, the third radiating stub 22 is arranged in a similar manner to the first radiating stub 12, specifically, as shown below. Figure 15 As shown, the third radiating branch 22 includes a fifth end 221 and a sixth end 222. The fifth end 221 is coupled to the second frame edge 62, and the sixth end 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 221 and the sixth end 222 to form a closed third annular structure. In addition, the fifth end 221 is closer to the third frame edge 63 than the first end 121, and the sixth end 222 is closer to the third frame edge 63 than the second end 122, so that there is no overlapping portion between the first radiating branch 12 and the third radiating branch 22.

[0174] It is understandable that the specific location of the second radiator 21 on the frame can be determined by the location of the connection point between the fifth end 221 and the sixth end 222 of the third radiating branch 22 and the frame. That is, the continuous metal structure of the frame located between the fifth end 221 and the sixth end 222 of the third radiating branch 22 and including the third frame edge 63 can serve as the second radiator 21.

[0175] Since the first end 121 and the fifth end 221 are spaced apart, and the second end 122 and the sixth end 222 are spaced apart, in practical applications, 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 can be connected at the same time, and the second end 122 and the sixth end 222 can also be connected.

[0176] You can continue to refer to Figure 15 The portion of the third radiating stub 22 located between the fifth end 221 and the sixth end 222 bends towards the third frame edge 63. The projected length of the third radiating stub 22 on the second frame edge 62 along the direction from the first frame edge 61 to the third frame edge 63 is L21. This length L21 satisfies the following relationship with the circumference L2 of the third annular structure: L21 ≥ (1 / 16) × L2. This confines more of the current generated by the antenna formed by the second radiator 21 within the region between the line connecting the fifth end 221 and the sixth end 222 and the third frame edge 63, thereby improving the isolation effect.

[0177] In practical applications, the length L21 can be made to satisfy the following relationship with the perimeter L2 of the third ring structure: (1 / 8)×L2≤L21≤(1 / 4)×L2. This can reduce the distance between the third radiating stub 22 and the third frame edge 63 by increasing the bending degree of the third radiating stub 22 towards the third frame edge 63, thereby further improving the confinement effect on the current generated by the second antenna operation, which is beneficial to improving the isolation between the first antenna and the second antenna.

[0178] Furthermore, the minimum distance L221 from the portion of the third radiating stub 22 that bends towards the third frame edge to the second frame edge 62 satisfies: L221 ≥ (1 / 20) × λ. Similarly, the minimum distance L222 from the portion of the third radiating stub 22 that bends towards the third frame edge to the fourth frame edge 64 satisfies: L222 ≥ (1 / 20) × λ. Here, λ is the dielectric wavelength corresponding to the operating frequency of the second antenna. This ensures that the third radiating stub 22 provides effective isolation, thereby guaranteeing the isolation between the first and second antennas.

[0179] In this application, the perimeter L2 of the third ring structure satisfies: (n+1)×λ×0.8<L2<(n+1)×λ×1.2, where n is an integer greater than or equal to 1, and λ is the dielectric wavelength corresponding to the operating frequency of the second antenna. This improves the communication stability of the antenna system while meeting the communication requirements of the second antenna.

[0180] It is worth mentioning that in the above formula, λ in (n+1)×λ×0.8 is the medium wavelength corresponding to the minimum operating frequency within the operating frequency range of the second antenna, and λ in (n+1)×λ×1.2 is the medium wavelength corresponding to the maximum operating frequency within the operating frequency range of the second antenna.

[0181] You can continue to refer to Figure 15 The fourth port of the RF chip is coupled to the second radiator 21 through the fourth feed point 24 to form a fourth antenna, so that the second port of the RF chip can feed the second antenna's operating frequency band RF signal to the second radiator 21 through the second feed point 23, and the fourth port of the RF chip can feed the fourth antenna's operating frequency band RF signal to the second radiator 21 through the fourth feed point 24.

[0182] It is worth mentioning that in this application, the operating frequency band of the second antenna and the operating frequency band of the fourth antenna can both cover the first frequency band, which can be, for example, the 2.4GHz Wi-Fi band or the 5GHz Wi-Fi band.

[0183] Furthermore, as described above, the operating frequency bands of the first antenna and the second antenna also cover the first frequency band. Therefore, in this embodiment, the operating frequency bands of the first antenna, the second antenna, the third antenna, and the fourth antenna can cover at least one of the same frequency bands, such as the 2.4GHz Wi-Fi band or the 5GHz Wi-Fi band. Thus, the antenna system provided in this application can include at least four antennas operating at the same frequency. These four antennas can operate simultaneously or not simultaneously, and the isolation between the antennas can be ensured through the specific design of each feed point and radiating stub.

[0184] For example, similar to the arrangement of the first ring structure described above, in Figure 15 In the illustrated embodiment, the second feed point 23 is located on the third frame edge 63, and the fourth feed point 24 is located on the fourth frame edge 64. In one possible embodiment, the distance d1 from the second feed point 23 to the midpoint of the third frame edge 63 satisfies the following relationship with the length L333 of the third frame edge 63: 0 ≤ d1 ≤ (1 / 4) × L333. The distance L23 from the fourth feed point 24 to the second feed point 23 satisfies the following relationship: (1 / 8) × L1 ≤ L23 ≤ (3 / 2) × L1. This makes it easier for the second and fourth antennas to excite resonant modes.

[0185] Additionally, the isolation can be adjusted by changing the distance between the second feed point 23 and the fourth feed point 24. Specifically, along the circumference of the third annular structure, the length L23 between the second feed point 23 and the fourth feed point 24 satisfies: (2n)×(1 / 4)×λ≤L23≤(2n+1)×(1 / 2)×λ, for example, (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 dielectric wavelength corresponding to the operating frequency of the second antenna. This allows the second and fourth antennas to excite a set of resonant modes, for example, enabling them to excite a set of orthogonal modes at appropriate locations, thereby improving the isolation between the second and fourth antennas.

[0186] It is worth mentioning that there are multiple ways to enable the second and fourth antennas to excite 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 antisymmetric mode, or the second and fourth antennas can be used to excite other possible modes respectively. This achieves the goal of improving the isolation between the second and fourth antennas.

[0187] In another possible embodiment of this application, when the excitation method of the second antenna and the fourth antenna is capacitive excitation, the second feed point 23 may also be located at the electric field zero point of the fourth antenna, and the fourth feed point 24 may be located at the electric field zero point of the second antenna. When the excitation method of the second antenna and the fourth antenna is inductive excitation, the second feed point 23 may be located at the current zero point of the fourth antenna, and the fourth feed point 24 may be located at the current zero point of the second antenna. This ensures that the communication requirements of the second radiator 21 are met while also guaranteeing that the third radiating stub 22 provides the required isolation effect.

[0188] In the above embodiments, the second feed point 23 is set at the third frame edge 63 and the fourth feed point 24 is set at the fourth frame edge 64 as examples to illustrate the impact of the arrangement of the two feed points on the isolation effect. In other possible embodiments, the fourth feed point 24 can also be set at the second frame edge 62, or at least one of the second feed point 23 and the fourth feed point 24 can be set at the third radiating stub 22. The distance between the two feed points can also be adjusted to excite a set of orthogonal modes in the second antenna and the fourth antenna at appropriate positions, thereby meeting the isolation requirements of the second antenna and the fourth antenna.

[0189] In addition to the above description of the first ring structure, similar to this application, the isolation effect can also be adjusted by changing the ratio of the length of the third radiating branch 22 to the length of the second radiator 21. In one possible embodiment of this application, the length L22 of the third radiating branch 22 satisfies: 0.8×n×(1 / 2)×λ≤L22≤1.2×n×(1 / 2)×λ, where n is an integer greater than or equal to 1, and λ is the wavelength of the medium corresponding to the operating frequency of the second antenna. This ensures that the third radiating branch 22 can achieve the required isolation effect while meeting the communication requirements of the second antenna.

[0190] In this application, the isolation effect can also be adjusted by adjusting the positions of the fifth end 221 and the sixth end 222. For example, in one possible embodiment, the fifth end 221 and the sixth end 222 are respectively located at a high-current point in the third ring structure. For instance, the fifth end 221 is electrically connected to a high-current point of the second antenna, and the sixth end 222 is connected to another high-current point of the second antenna; or, the fifth end 221 is connected to a high-current point of the fourth antenna, and the sixth end 222 is connected to another high-current point of the fourth antenna. This allows the third radiating stub 22 to confine most of the current generated by the second and fourth antennas to the side of the connection between the fifth end 221 and the sixth end 222 near the third frame edge 63, and significantly reduces the current transmitted to the first frame edge 61, thereby improving the isolation.

[0191] It is worth mentioning that since the isolation effect achievable by specifically configuring each part of the third ring structure is similar to that described above for the first ring structure, it will not be elaborated upon here.

[0192] Figure 16 For traditional antenna systems without first and third radiating stubs and Figure 15 The S-parameter curves of the antenna system are shown. Among them, in... Figure 16 In the text, case 1 represents a traditional antenna system, and case 2 represents... Figure 15 The antenna system shown is then... Figure 16As can be seen, compared with the traditional solution, the design provided in this application can improve the isolation between the first antenna and the second antenna from -2dB to -25dB. This is because the first radiating stub 12 can confine most of the current generated by the operation of the first antenna and the third antenna to the side of the connection between the first end 121 and the second end 122 close to the first frame edge 61, and significantly reduce the current transmitted to the third frame edge 63. At the same time, the third radiating stub 22 can confine most of the current generated by the operation of the second antenna and the fourth antenna to the side of the connection between the fifth end 221 and the sixth end 222 close to the third frame edge 63, and significantly reduce the current transmitted to the first frame edge 61, thereby achieving the purpose of improving the isolation.

[0193] To further improve the isolation of the antenna system, radiating stubs can be added to the antenna system. For example, refer to... Figure 17 , Figure 17 This is another schematic diagram of the antenna system of the communication terminal provided in an embodiment of this application. In this embodiment, the antenna system further includes a second radiating stub 31, and the projection of the second radiating stub 31 falls within the outline range of the projection of the first radiator along the direction from the second frame edge 62 to the fourth frame edge 64. In this application, the second radiating stub 31 is arranged similarly to the first radiating stub 12. Simply put, the second radiating stub 31 includes a third end 311 and a fourth end 312. The third end 311 is coupled to the second frame edge 62, and the fourth end 312 is coupled to the fourth frame edge 64. The third end 311 is closer to the third frame edge 63 than the first end 121, and the fourth end 312 is closer to the third frame edge 63 than the second end 122.

[0194] Additionally, it is worth mentioning that when the antenna system includes a first radiating stub 12, a third radiating stub 22, and a second radiating stub 31, the third end 311 is located between the first end 121 and the fifth end 221, and the fourth end 312 is located between the second end 122 and the sixth end 222, so that there is no overlap between any of the first radiating stub 12, the third radiating stub 22, and the second radiating stub 31.

[0195] You can continue to refer to Figure 17 The second radiating branch 31 is connected to the first radiator 11 through the third end 311 and the fourth end 312 to form a third ring structure, and the portion of the second radiating branch 31 located between the third end 311 and the fourth end 312 is bent toward the first frame edge 61.

[0196] In one possible embodiment of this application, the length L14 of the second radiating stub 31 satisfies: L14 = n × (1 / 4) × λ, where n is an integer greater than or equal to 1, and λ is the wavelength of the medium corresponding to the operating frequency of the first radiator 11. This ensures that the second radiating stub 31 provides the required isolation while meeting the communication requirements of the first radiator 11.

[0197] Figure 18 for Figure 17 and Figure 15 The S-parameter curves of the antenna system are shown. Figure 18 In the middle, case1 represents Figure 15 The antenna system shown, case 2 represents Figure 17 The antenna system shown. A comparison reveals... Figure 17 The antenna system shown can further improve its isolation by adding a second radiating stub 31.

[0198] In some possible embodiments of this application, the antenna system can further improve isolation by adding radiating branches. Figure 19 This is another schematic diagram of the antenna system of the communication terminal provided in an embodiment of this application. Figure 19 In the illustrated embodiment, the antenna system further includes a fourth radiating stub 41, which is arranged similarly to the third radiating stub 22. Simply put, the fourth radiating stub 41 includes a seventh end 411 and an eighth end 412. The seventh end 411 is located between the first end 121 and the fifth end 221, and the eighth end 412 is located between the second end 122 and the sixth end 222. Additionally, in Figure 19 In the embodiment shown, the seventh end 411 is also located between the third end 311 and the fifth end 221, and the eighth end 412 is also located between the fourth end 312 and the sixth end 222. That is to say, there is no overlap between the various radiating branches in the antenna system.

[0199] You can continue to refer to Figure 19 The fourth radiating branch 41 is connected to the second radiator 21 through the seventh end 411 and the eighth end 412 to form a closed fourth ring structure, and the portion of the fourth radiating branch 41 located between the seventh end 411 and the eighth end 412 bends toward the third frame edge 63.

[0200] In one possible embodiment of this application, the length L24 of the fourth radiating stub 41 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 dielectric wavelength corresponding to the operating frequency of the second antenna. This ensures that the fourth radiating stub 41 provides the required isolation while meeting the communication requirements of the second antenna.

[0201] It is understandable that the adoption Figure 19 The antenna system design shown can further improve the isolation of the antenna system.

[0202] Since the communication terminal includes a floor 51, which can be located on or inside the housing of the communication terminal, and the frame of the communication terminal can be disposed on the housing, in one possible embodiment of this application, the frame can be disposed around the floor 51. Furthermore, considering that the current generated by the antenna in the antenna system can also be transmitted through the floor 51, slots can be made in the floor 51 to block the current transmission path. For specific implementation, refer to... Figure 20 , Figure 20 This is another schematic diagram of the antenna system provided in an embodiment of this application. Similar to the above... Figure 15 Compared to the antenna system shown, in Figure 20 In the floor 51, there are two openings, namely a first opening 511 and a second opening 512. Both the first opening 511 and the second opening 512 are located between the first radiator and the second radiator 21 along the direction from the first frame edge 61 to the third frame edge. Furthermore, the first opening 511 extends towards the first frame edge 61, and the second opening 512 extends towards the third frame edge 63, so there is no overlap between the first opening 511 and the second opening 512.

[0203] In another possible embodiment of this application, the slot on the floor 51 is also located between the first radiating stub 12 and the third radiating stub 22. This allows the slot on the floor, together with the various radiating stubs, to block the current transmission path, thereby improving the isolation of the antenna system.

[0204] Figure 21 for Figure 15 and Figure 20 The S-parameter curves of the antenna system. Where case1 represents... Figure 15 The antenna system shown, case 2 represents Figure 20 The antenna system shown. A comparison reveals... Figure 20 The antenna system shown can significantly improve the isolation between the first antenna and the second antenna by setting a slot on the floor 51, thereby further improving the isolation of the entire antenna system.

[0205] It is understood that in this application, the isolation of the antenna system can be adjusted by adjusting the length of the slot on the floor 51. In a specific implementation, in one possible embodiment of this 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.

[0206] In this application, the length of the slit can be understood as the straight line length of the slit stretched along the line connecting its two ends. It is worth mentioning that... Figure 20 This application only demonstrates one possible arrangement of the gaps on the floor 51. In other embodiments of this application, the gaps on the floor 51 may also be arranged in other ways, and this application does not limit them. In addition, the number of gaps on the floor 51 may be set to one or more depending on the communication requirements of the actual application scenario.

[0207] Figure 22 This is another schematic diagram of the antenna system of the communication terminal provided in an embodiment of this application. In this embodiment, the antenna system is provided with a first radiating stub 12, a third radiating stub 22, and a fourth radiating stub 41, and the floor 51 is provided with a first slot 511 and a second slot 512. Furthermore, it is worth mentioning that... Figure 22 In the illustrated embodiment, the portion of the first radial branch 12 that bends toward the first frame edge 61 is serpentine, the portion of the third radial branch 22 that bends toward the third frame edge 63 is serpentine, and the portion of the fourth radial branch 41 that bends toward the third frame edge 63 is C-shaped.

[0208] Figure 23 for Figure 22 The S-curves of the first, second, third, and fourth antennas of the antenna system shown are illustrated. Figure 23 As shown, the isolation between each antenna is high. This is because in this antenna system, the first and third antennas can excite one set of orthogonal modes, and the second and fourth antennas can excite another set of orthogonal modes. Thus, along the direction from the first frame edge 61 to the third frame edge 63, the current can be confined to both sides of the frame respectively; at the same time, the slots on the ground 51 can block the current transmission path.

[0209] Furthermore, by bending the first radiating stub 12 into a serpentine shape, the isolation requirements of the first and third antennas can be met while simultaneously achieving a miniaturized design of the first radiating stub 12, thereby reducing the space occupied by the first radiating stub 12 within the communication equipment. Similarly, bending the third radiating stub 22 into a serpentine shape allows for the isolation requirements of the second and fourth antennas to be met while simultaneously achieving a miniaturized design of the third radiating stub 22, thus reducing the space occupied by the third radiating stub 22 within the communication equipment.

[0210] Figure 24 This is another schematic diagram of the antenna system of the communication terminal provided in an embodiment of this application. (Similar to the above...) Figure 15 The difference between the embodiments shown is that, Figure 24 The antenna system shown also includes a third radiator 71 and a fourth radiator 81. The third radiator 71 is disposed on the fourth frame edge 64, and the fourth radiator 81 is disposed on the second frame edge 62. The first radiator 11, the third radiator 71, the second radiator 21, and the fourth radiator 81 are connected to form a closed integrated structure. Furthermore, the fifth port of the RF chip is coupled to the third radiator 71 through the fifth feed point 72 to form a fifth antenna, and the sixth port of the RF chip is coupled to the fourth radiator 81 through the sixth feed point 82 to form a sixth antenna. The operating frequency bands of the first antenna, the second antenna, the fifth antenna, and the sixth antenna all cover the first frequency band, which may be, for example, the 2.4GHz Wi-Fi band or the 5GHz Wi-Fi band.

[0211] Figure 25a for Figure 24 The isolation curves between the fifth antenna and the other antennas in the antenna system shown. Figure 25b for Figure 24 The diagram shows the isolation curves between the sixth antenna and the other antennas in the antenna system. It can be seen that the fifth and sixth antennas have high isolation from the other antennas.

[0212] This is because, using the antenna system design provided in this application, the majority of the current generated by the first radiator 11 can be confined to the side of the line connecting the two ends of the first radiating branch 12 facing the first frame edge 61 through the first ring structure formed by the first radiator 11 and the first radiating branch 12. Similarly, the majority of the current generated by the second radiator 21 can be confined to the side of the line connecting the two ends of the third radiating branch 22 facing the third frame edge 63 through the second ring structure formed by the second radiator 21 and the third radiating branch 22. Simultaneously, the current generated by the modes excited by the fifth and sixth antennas can be confined between the two ring structures.

[0213] In one possible embodiment of this 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 antisymmetric mode, or the fifth antenna can be used to excite an antisymmetric mode and the sixth antenna can be used to excite a symmetric mode. This can effectively improve the isolation of the antenna system.

[0214] The above embodiments are merely illustrative examples of the specific configuration of the antenna system provided in this application. Based on its design principles, the specific configuration of the antenna system can be adapted to meet the communication requirements of actual application scenarios. For example, the antenna system may include one or more of the following: a first radiating stub 12, a third radiating stub 22, a second radiating stub 31, a fourth radiating stub 41, and a slot; or each radiating stub may be bent into a C-shape, a serpentine shape, or other possible shapes; or the number of antennas in the antenna system may be adjusted. All possible configurations of the antenna system are not listed here, but they should all be understood to fall within the protection scope of this application.

[0215] As mentioned above, the solution for improving the isolation of the antenna system provided in this application is applicable not only to completely enclosed metal frames, but also to non-enclosed frames including openings. Figure 26 This is a schematic diagram of an antenna system for an antenna box in a practical application provided by an embodiment of this application. It can be referred to concurrently. Figure 2 and Figure 26 Since the antenna box 700 and the display 800 can communicate via connecting components such as a circuit board, an opening 702 can be provided on the side of the antenna box 700 facing the display 800 to allow for the passage of connecting components such as the circuit board. Therefore, in Figure 26 In the antenna box 700 shown, its frame is a non-closed type. Furthermore, it can be understood that... Figure 26 The other three connected surfaces of the frame of the antenna box 700 shown can all be used as radiators to enable communication functions.

[0216] Figure 26 Other structures of the antenna box shown can be configured with reference to any of the above embodiments, and will not be described in detail here.

[0217] In addition, based on the design principles of the antenna system provided in this application, the antenna box can also be designed with specific appearance requirements in practical applications.

[0218] It is understood that when one edge of the communication terminal's frame includes an opening, such as the second frame edge 62 including an opening 702, then the opening 702 is located between the first radiator 11 and the second radiator 21. Additionally, the antenna system may also include a third radiator 71, which is disposed on the fourth frame edge 64. The fifth port of the RF chip is coupled to the third radiator 71 through a fifth feed point to form a fifth antenna. The first radiator 11, the third radiator 71, and the second radiator 21 are connected sequentially, and the operating frequency bands of the first antenna, the second antenna, and the fifth antenna all cover the first frequency band, which may be, for example, the 2.4GHz Wi-Fi band or the 5GHz Wi-Fi band. The first radiator 11, the second radiator 21, and the third radiator 71 can all be configured according to any of the above embodiments, allowing the antenna system to have an architecture including five antennas operating at the same frequency. In this architecture, the isolation between the antennas can meet communication requirements by confining the current through the first radiating stub 12 and the third radiating stub 22.

[0219] The solution for improving the isolation of antenna systems provided in this application is applicable not only to fixed communication terminals such as antenna boxes, but also to various other communication terminals with a four-sided metal structure. For example, it can be used in mobile terminals such as mobile phones. Figures 27a to 27d Several possible configurations of the antenna system in a mobile terminal are presented, which are similar to the configurations of the antenna systems in the above embodiments and the isolation effects they can achieve, and will not be described in detail here.

[0220] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A communication terminal, characterized in that, The communication terminal includes a frame and an antenna system. The frame is arranged circumferentially around the communication terminal. The frame includes 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 opposite to the third frame edge, and the second frame edge is opposite to the fourth frame edge. The antenna system includes a first radiator, a second radiator, a first radiating stub, and a radio frequency chip, wherein: The first radiator is disposed on the first frame edge, the second frame edge, and the fourth frame edge; at least a portion of the second radiator is disposed 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 radiating branch includes a first end and a second end. The first end is coupled to the second frame edge, and the second end is coupled to the fourth frame edge. The first radiating branch is coupled to the first radiator through the first end and the second end to form a first ring structure, and the portion of the first radiating branch located between the first end and the second end bends toward the first frame edge. The first port of the radio frequency chip is coupled to the first radiator through a first feed point to form a first antenna, and the second port of the radio frequency chip is coupled to the second radiator through a second feed point to form a second antenna. The operating frequency bands of the first antenna and the second antenna both cover the first frequency band.

2. The communication terminal as described in claim 1, characterized in that, Along the direction from the first frame edge to the third frame edge, the projection length of the first radiating branch on the second frame edge is L11; the length L11 and the perimeter L1 of the first annular structure satisfy: L11≥(1 / 16)×L1.

3. The communication terminal as described in claim 2, characterized in that, The length L11 and the circumference L1 of the first ring structure satisfy the following condition: (1 / 8)×L1≤L11≤(1 / 4)×L1.

4. The communication terminal as described in claim 2 or 3, characterized in that, The perimeter L1 of the first ring structure satisfies: (n+1)×λ×0.8<L1<(n+1)×λ×1.2, 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.

5. The communication terminal as described in any one of claims 1 to 4, characterized in that, The minimum distance L12 from the portion of the first radiating stub that bends toward the first frame edge to the second frame edge satisfies: L12≥(1 / 20)×λ; the minimum distance L13 from the portion of the first radiating stub that bends toward the first frame edge to the fourth frame edge satisfies: L13≥(1 / 20)×λ, where λ is the dielectric wavelength corresponding to the operating frequency of the first antenna.

6. The communication terminal as described in any one of claims 1 to 5, characterized in that, The length L14 of the first radiating stub satisfies: 0.8×n×(1 / 2)×λ≤L14≤1.2×n×(1 / 2)×λ, where n is an integer greater than or equal to 1, and λ is the wavelength of the medium corresponding to the operating frequency of the first antenna.

7. The communication terminal as described in any one of claims 1 to 6, characterized in that, The third port of the radio frequency chip is coupled to the first radiator through the third feed point to form a third antenna. The operating frequency band of the third antenna and the operating frequency band of the first antenna both cover the first frequency band. Along the circumference of the first annular structure, the length L15 of the portion between the first feed point and the third feed point 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 the dielectric wavelength corresponding to the operating frequency of the first antenna.

8. The communication terminal as described in claim 7, characterized in that, The first power supply point is located on the first frame edge, and the third power supply point is located on the second frame edge.

9. The communication terminal as described in claim 8, characterized in that, The distance d from the first feed point to the midpoint of the first frame edge satisfies the following relationship with the length L111 of the first frame edge: 0 ≤ d ≤ (1 / 4) × L111; the distance L15 from the third feed point to the first feed point satisfies the following relationship: (1 / 8) × L1 ≤ L15 ≤ (3 / 2) × L1.

10. The communication terminal as described in claim 8 or 9, characterized in that, When the excitation method of the first antenna and the third antenna is capacitive excitation, the first feed point is located at the electric field zero point of the third antenna, and the third feed point is located at the electric field zero point of the first antenna; when the excitation method of the first antenna and the third antenna is inductive excitation, the first feed point is located at the current zero point of the third antenna, and the third feed point is located at the current zero point of the first antenna.

11. The communication terminal as described in claim 10, characterized in that, The first end is connected to a high-current point of the first antenna, and the second end is connected to another high-current point of the first antenna; or the first end is connected to a high-current point of the third antenna, and the second end is connected to another high-current point of the third antenna.

12. The communication terminal as described in any one of claims 1 to 11, characterized in that, The portion of the first radiating branch that bends toward the edge of the first frame has a C-shaped bend or a serpentine bend.

13. The communication terminal as described in any one of claims 1 to 12, characterized in that, The antenna system further includes a second radiating stub, and the projection of the second radiating stub falls within the outline of the projection of the first radiator along the direction from the second frame edge to the fourth frame edge; the second radiating stub includes a third end and a fourth end, the third end being coupled to the second frame edge, the fourth end being coupled to the fourth frame edge, the third end being closer to the third frame edge relative to the first end, and the fourth end being closer to the third frame edge relative to the second end; The second radiating branch is coupled to the first radiator through the third end and the fourth end to form a closed second ring structure, and the portion of the second radiating branch located between the third end and the fourth end bends toward the first frame edge.

14. The communication terminal as described in claim 13, characterized in that, The length L16 of the second radiating stub 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 dielectric wavelength corresponding to the operating frequency of the first antenna.

15. The communication terminal as described in any one of claims 1 to 14, characterized in that, The antenna system further includes a third radiating stub, the projection of which falls within the outline of the projection of the second radiator along the direction from the second frame edge to the fourth frame edge; the third radiating stub includes a fifth end and a sixth end, the fifth end being coupled to the second frame edge, the sixth end being coupled to the fourth frame edge, the fifth end being closer to the third frame edge relative to the first end, and the sixth end being closer to the third frame edge relative to the second end; the third radiating stub and the second radiator are coupled to form a closed third ring structure, and the portion of the third radiating stub located between the fifth end and the sixth end bends toward the third frame edge.

16. The communication terminal as described in claim 15, characterized in that, The fourth port of the radio frequency chip is coupled to the second radiator through the fourth feed point to form a fourth antenna. The operating frequency band of the second antenna and the operating frequency band of the fourth antenna both cover the first frequency band. Along the outline of the third annular structure, the length L23 of the portion between the second feed point and the fourth feed 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 the dielectric wavelength corresponding to the operating frequency of the second antenna.

17. The communication terminal as described in claim 15 or 16, characterized in that, The antenna system further includes a fourth radiating stub, the projection of which falls within the outline of the projection of the second radiator along the direction from the second frame edge to the fourth frame edge; the fourth radiating stub includes a seventh end and an eighth end, the seventh end being connected to the second frame edge, the eighth end being connected to the fourth frame edge, the seventh end being located between the first end and the third end, and the eighth end being located between the second end and the fourth end; The fourth radiating branch is coupled to the second radiator through the seventh end and the eighth end to form a closed fourth ring structure, and the portion of the fourth radiating branch located between the seventh end and the eighth end bends toward the third frame edge.

18. The communication terminal as described in any one of claims 15 to 17, characterized in that, The antenna system further includes a third radiator and a fourth radiator. The third radiator is disposed on the fourth frame edge, and the fourth radiator is disposed on the second frame edge. The first radiator, the third radiator, the second radiator, and the fourth radiator are connected to form a closed integral structure. The fifth port of the radio frequency chip is coupled to the third radiator through the fifth feed point to form a fifth antenna, and the sixth port of the radio frequency chip is coupled to the fourth radiator through the sixth feed point to form a sixth antenna; the 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 as described in any one of claims 15 to 17, characterized in that, The second frame edge includes an opening located between the first radiator and the second radiator; the antenna system further includes a third radiator disposed on 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 to the third radiator through the fifth feed point to form a fifth antenna. The operating frequency bands of the first antenna, the second antenna, and the fifth antenna all cover the first frequency band.

20. The communication terminal according to any one of claims 1 to 19, characterized in that, The communication terminal further includes a housing and a floor, the frame is disposed on the housing, the floor is disposed on or inside the housing, and the frame is disposed around the floor; The floor includes at least one slit along the direction from the first frame edge to the third frame edge, the at least one slit being located between the first radiator and the second radiator.

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