Antenna and terminal device

Abstract

Provided in the embodiments of the present application are an antenna and a terminal device. The antenna comprises a first branch, a second branch, an inductive structure and a capacitive structure. The first branch, the inductive structure and the second branch form a first antenna, and the first antenna is used for generating a first resonance. The first branch, the capacitive structure and the second branch form a second antenna, and the second antenna is used for generating a second resonance. The working frequency of the second antenna in the second resonance is higher than the working frequency of the first antenna in the first resonance. By means of the radiation body reconstruction, the present application achieves the arrangement of two or more antennas in a limited space, and a terminal device can accommodate more antennas, thus improving the radio frequency transceiving performance of the terminal device.

Description

Antennas and terminal equipment

[0001] This application claims priority to Chinese Patent Application No. 202410142347.3, filed with the China National Intellectual Property Administration on January 31, 2024, entitled “Antenna and Terminal Equipment”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to the field of radio frequency communication technology, and more particularly to an antenna and a terminal device. Background Technology

[0003] Mobile phones and other terminal devices need to communicate through the mobile communication networks provided by operators and also need to have other communication functions, such as Wi-Fi, Bluetooth, and infrared. For mobile phones, communication signals are transmitted and received via antennas. Due to the diverse communication methods of mobile phones, a relatively large number of antennas need to be installed inside the phone. In the design of antennas within terminal devices, the limited space makes antenna layout a key challenge.

[0004] The frame of a terminal device houses numerous antennas. With the addition of new frequency band specifications for antennas, how to reuse antenna segments without increasing the frame size, and how to reuse the same segment to achieve different antenna functions, is a problem that the industry urgently needs to solve. Summary of the Invention

[0005] This application provides an antenna and a terminal device that can reuse antenna stubs within a limited space to enable the construction of different antennas.

[0006] In a first aspect, embodiments of this application provide an antenna comprising a first stub, a second stub, an inductive structure, and a capacitive structure. One end of the first stub is an open-circuit terminal, and the other end is a first coupling terminal. One end of the second stub is a second coupling terminal, and the other end is a ground terminal, with a gap formed between the second coupling terminal and the first coupling terminal. One end of the inductive structure is coupled to the first stub, and the other end of the inductive structure is coupled to the second stub. One end of the capacitive structure is coupled to the first stub, and the other end of the capacitive structure is coupled to the second stub. The first stub, the inductive structure, and the second stub constitute a first antenna, which generates a first resonance. The first stub, the capacitive structure, and the second stub constitute a second antenna, which generates a second resonance. The operating frequency of the second antenna at the second resonance is higher than the operating frequency of the first antenna at the first resonance.

[0007] This application embodiment utilizes the radiating part composed of the first and second branches in combination with inductive and capacitive structures to realize the arrangement of antennas in at least two different resonant frequency bands. This application embodiment realizes the arrangement of two or more antennas in a limited space through the reconstruction of the radiator, which can save the space occupied by the antenna in the terminal device. For the terminal device, it can accommodate more antennas and improve the radio frequency transceiver performance of the terminal device.

[0008] In one possible implementation, the sum of the electrical lengths of the second stub and the first stub is less than one-quarter of the wavelength corresponding to the resonant frequency of the first resonance. This implementation, by constraining the relationship between the sum of the electrical lengths of the second and first stubs and the wavelength corresponding to the resonant frequency of the first resonance, combined with the coupling of the second stub, the first stub, and the inductive connection, facilitates the construction of the first antenna and satisfies the requirement that the first antenna generates the first resonance.

[0009] In one possible implementation, the sum of the electrical lengths of the second stub and the first stub is greater than one-quarter of the wavelength corresponding to the resonant frequency of the second resonance. This implementation, by constraining the relationship between the sum of the electrical lengths of the second and first stubs and the wavelength corresponding to the resonant frequency of the first resonance, combined with the coupling of the second stub, the first stub, and the capacitive connection, facilitates the construction of a second antenna and satisfies the requirement that the second antenna generates a second resonance.

[0010] In one possible implementation, the inductance value of the inductive structure ranges from 3nH to 10nH. This embodiment of the application, by constraining the effective inductance value range of the inductive structure to greater than or equal to 3nH and less than or equal to 10nH, ensures that the inductive structure has a minimal impact on the second antenna, thus benefiting the performance of the second antenna. If the inductive structure 25 has an inductance value less than 3nH, its impact on the second antenna is significant.

[0011] In one possible implementation, the capacitance of the capacitive structure is adjustable, and the capacitive structure is used to tune the resonance generated by the second antenna. This embodiment of the application makes it easier to tune the second antenna by setting the capacitive structure to have an adjustable capacitance. Since the capacitive structure is located at the position corresponding to the gap between the first and second stubs, which is a weak point in the electric field, the first antenna is not sensitive to adjustments in the effective capacitance value of the capacitive structure. Therefore, adjustments to the effective capacitance value of the capacitive structure have a relatively small impact on the first antenna.

[0012] In one possible implementation, the inductive structure is a lumped inductor or a distributed inductor; or, the capacitive structure is a lumped capacitor or a distributed capacitor. The antenna provided in this application embodiment can flexibly select various inductive and / or capacitive structures, enabling the antenna to have more application scenarios.

[0013] In one possible implementation, the antenna further includes a first feed structure and a second feed structure. The second stub has a first feed point and a second feed point. Along the extension direction of the second stub, the grounding terminal, the first feed point, the second feed point, and the second coupling terminal are arranged sequentially at intervals. The first feed structure and the first feed point are coupled together and used to feed signals in a first frequency band. The second feed structure and the second feed point are coupled together and used to feed signals in a second frequency band. The first resonance corresponds to the signal in the first frequency band, and the second resonance corresponds to the signal in the second frequency band. This solution, by setting the first feed point and the second feed point on the second stub, and feeding radio frequency signals to the first feed point and the second feed point respectively through the first feed structure and the second feed structure, facilitates the separate tuning and matching of the first antenna and the second antenna, and helps ensure that both the first antenna and the second antenna have good performance.

[0014] In one possible implementation, the antenna further includes a first feed structure and a second feed structure. A first feed point is located on the second stub, and a second feed point is located on the first stub. The first feed structure and the first feed point are coupled together and used to feed signals in a first frequency band. The second feed structure and the second feed point are coupled together and used to feed signals in a second frequency band. The first resonance corresponds to the signal in the first frequency band, and the second resonance corresponds to the signal in the second frequency band. This solution, by setting the first and second feed points on the second stub and feeding RF signals to the first and second feed points respectively through the first and second feed structures, facilitates the separate tuning and matching of the first and second antennas, ensuring good performance for both antennas. This solution adjusts the positions of the first and second feed points, making antenna feeding and matching more flexible.

[0015] In one possible implementation, the antenna includes a total feed structure, with the first or second stub having a total feed point. The total feed structure and the total feed point are coupled together for feeding a first frequency band signal and a second frequency band signal to the total feed point. The first resonance corresponds to the first frequency band signal, and the second resonance corresponds to the second frequency band signal. This solution, by feeding the first and second frequency band signals to the total feed point through the total feed structure, facilitates a compact overall antenna structure and saves space within the terminal equipment.

[0016] In one possible implementation, the antenna includes a main feed structure, and the second branch has a main feed point. The main feed structure and the main feed point are electrically connected for feeding a first frequency band signal and a second frequency band signal to the main feed point. The first resonance corresponds to the first frequency band signal, and the second resonance corresponds to the second frequency band signal. This solution feeds the first and second frequency band signals to the main feed point through the main feed structure, which is beneficial for a compact overall antenna structure and saves space within the terminal equipment. By changing the position of the feed point, with the main feed point located in the second branch, the position of the main feed point can be adjusted according to different antenna matching requirements, making the antenna feeding and matching more flexible, which is beneficial for tuning the antenna and achieving better radiation performance.

[0017] In one possible implementation, the antenna further includes a switch coupled between the open terminal of the first stub and the ground plane. The switch provided in this solution is used to achieve tuning between a parallel capacitor and a parallel inductor at the open terminal of the first stub to achieve a tuning frequency. When the switch is used to achieve the state of the parallel capacitor, it is used to achieve tuning that shifts the resonance to a lower frequency; when the switch is used to achieve the state of the parallel inductor, it is used to achieve tuning that shifts the resonance to a higher frequency.

[0018] In one possible implementation, the first resonant frequency band includes at least one communication frequency band within the frequency range of 698MHz-960MHz; and / or, the second resonant frequency band includes at least one communication frequency band within the frequency range of 1700MHz-2700MHz. This solution achieves matching of the first antenna and the second antenna for specific application scenarios by constraining the first resonant frequency band of the first antenna and the second resonant frequency band of the second antenna.

[0019] In one possible implementation, the antenna further includes a parasitic stub, with the open ends of the parasitic stub and the first stub spaced apart. One embodiment of this application utilizes a parasitic stub to participate in the resonance of the second antenna, thereby improving the radiation performance of the second antenna and enabling two resonance modes. By coupling the parasitic stub to the first antenna and participating in the resonance of the first antenna, two resonance modes of the first antenna can be achieved.

[0020] In one possible implementation, the antenna further includes a first switch coupled between the first stub and the second stub. The first switch is used to tune the first resonance of the first antenna and the second resonance of the second antenna. This solution uses the first switch to tune the first resonance of the first antenna and the second resonance of the second antenna.

[0021] In one possible implementation, the antenna further includes a second switch. One end of the second switch is coupled to ground, and the other end is coupled to the open circuit end of the first stub or the parasitic coupling end of the parasitic stub. The parasitic coupling end is the end of the parasitic stub adjacent to the first stub. The second switch is used to tune a resonant frequency band in the second resonance of the second antenna. This scheme uses a second switch connected in parallel between the first stub and the parasitic stub. When the second switch is connected to the first stub and ground, it is used to tune the resonant mode of the antenna in which the first and second stubs participate in radiation. When the second switch is connected to the parasitic stub and ground, it is used to tune the resonant mode of the antenna in which the parasitic stub participates in radiation. In one possible implementation, the second switch is located at a position corresponding to the gap between the first stub and the parasitic stub.

[0022] In one possible implementation, the electrical length of the parasitic stub is one-quarter of the wavelength corresponding to the resonant frequency of the first resonance. This scheme, by constraining the electrical length of the parasitic stub, enables the stub to operate within the frequency range of the first resonance, participate in the radiation of the first antenna, and allows the first antenna to generate two resonance modes.

[0023] Secondly, embodiments of this application provide an antenna, which includes a first radiating stub, a second radiating stub, and a parasitic stub. One end of the first radiating stub is a ground terminal, and the other end of the first radiating stub is a first coupling terminal. One end of the second radiating stub is a second coupling terminal, and the other end of the second radiating stub is a third coupling terminal. One end of the parasitic stub is a ground terminal, and the other end of the parasitic stub is a fourth coupling terminal. The second radiating stub is located between the parasitic stub and the first radiating stub. The second coupling terminal of the second radiating stub and the first coupling terminal of the first radiating stub are opposite to each other and spaced apart. The third coupling terminal of the second radiating stub and the fourth coupling terminal of the parasitic stub are opposite to each other and spaced apart.

[0024] The antenna further includes the inductive structure, one end of which is coupled to the parasitic stub and the other end of which is coupled to the second radiating stub; a portion of the parasitic stub, the inductive structure, and a portion of the second radiating stub constitute a first antenna, which is used to generate a first resonance;

[0025] The antenna further includes a capacitive structure coupled between the first radiating stub and the second radiating stub. The first radiating stub, the capacitive structure, and the second radiating stub constitute a second antenna, which is used to generate a second resonance.

[0026] The second antenna operates at a higher frequency at the second resonance than the first antenna operates at the first resonance.

[0027] This application embodiment connects an inductive structure in parallel and a capacitive structure in series between the second radiating stub and the parasitic stub. A first antenna and a second antenna can be constructed using the first radiating stub, the second radiating stub, the parasitic stub, and the inductive and capacitive structures. The first antenna uses an inductive structure, and the second antenna uses a capacitive structure. This application constructs different antenna radiators based on the same radiating stub, achieving antenna reconfiguration. This facilitates the arrangement of two or more antennas within a limited space, saving space occupied by antennas within the terminal device. For the terminal device, this allows for the accommodation of more antennas, improving the RF transceiver performance of the terminal device.

[0028] In one possible implementation, the sum of the electrical lengths of the second stub and the first stub is less than one-quarter of the wavelength corresponding to the resonant frequency of the first resonance. This implementation, by constraining the relationship between the sum of the electrical lengths of the second and first stubs and the wavelength corresponding to the resonant frequency of the first resonance, combined with the coupling of the second stub, the first stub, and the inductive connection, facilitates the construction of the first antenna and satisfies the requirement that the first antenna generates the first resonance.

[0029] In one possible implementation, the sum of the electrical lengths of the second stub and the first stub is greater than one-quarter of the wavelength corresponding to the resonant frequency of the second resonance. This implementation, by constraining the relationship between the sum of the electrical lengths of the second and first stubs and the wavelength corresponding to the resonant frequency of the first resonance, combined with the coupling of the second stub, the first stub, and the capacitive connection, facilitates the construction of a second antenna and satisfies the requirement that the second antenna generates a second resonance.

[0030] In one possible implementation, the inductive structure is a distributed inductor, with one end coupled to the parasitic stub at a position between the two ends of the parasitic stub, and the other end coupled to the second radiating stub at a position between the two ends of the second radiating stub; or, the inductive structure is a lumped inductor, with one end coupled to the third coupling terminal of the second radiating stub, and the other end coupled to the fourth coupling terminal of the parasitic stub. The antenna provided in this application embodiment can flexibly select various inductive structure settings, enabling the antenna to have more application scenarios.

[0031] In one possible implementation, the antenna further includes a first switch coupled between the first radiating stub and the second radiating stub. The first switch is used to tune one of the resonant frequency bands of the second resonance of the second antenna. This solution uses the first switch to tune the first resonance of the first antenna and the second resonance of the second antenna.

[0032] In one possible implementation, the antenna further includes a second switch coupled between the second radiating stub and the parasitic stub. The second switch is used to tune the first resonance of the first antenna and to tune another resonant frequency band of the second resonance of the second antenna. This solution uses a second switch connected in parallel between the second radiating stub and the parasitic stub. When the second switch is coupled to ground, it is used to tune the resonant modes of the antennas radiating from the second and first radiating stubs. When the second switch is coupled to ground, it is used to tune the resonant mode of the antenna radiating from the parasitic stub.

[0033] Thirdly, embodiments of this application provide a terminal device, which includes a radio frequency chip and an antenna in any possible implementation of the first or second aspect, wherein the radio frequency chip is used to power the antenna. Attached Figure Description

[0034] Figure 1 is a schematic diagram of a terminal device provided in one embodiment of this application;

[0035] Figure 2 is a schematic diagram of a terminal device provided in one embodiment of this application;

[0036] Figure 3 is a schematic diagram of a terminal device provided in one embodiment of this application;

[0037] Figure 4 is a schematic diagram of the hardware architecture of the antenna system in a terminal device provided in one embodiment of this application.

[0038] Figures 5A and 5B are schematic diagrams of an antenna provided in one embodiment of this application. Figure 5A shows the current distribution of a first antenna, and the direction indicated by the arrowed indicator line in Figure 5A is the current distribution of the first antenna at a certain time period. Figure 5B shows the current distribution of a second antenna, and the direction indicated by the arrowed indicator line in Figure 5B is the current distribution of the second antenna at a certain time period.

[0039] Figure 5C is a schematic diagram of the overall system efficiency and radiation efficiency of the second antenna in the antenna provided by the embodiments shown in Figures 5A and 5B.

[0040] Figure 5D is a schematic diagram of the S11 curve of the second antenna in the embodiment provided by Figures 5A and 5B;

[0041] Figure 5E is a schematic diagram of the S22 curve of the first antenna in the embodiment provided by Figures 5A and 5B;

[0042] Figure 5F is a schematic diagram of the overall system efficiency and radiation efficiency of the first antenna in the embodiment provided in Figures 5A and 5B.

[0043] Figure 6 is a schematic diagram of an antenna provided in one embodiment of this application. The direction indicated by the arrowed indicator line in Figure 6 is the current distribution of the first antenna at a certain time period.

[0044] Figure 7 is a schematic diagram of an antenna provided in one embodiment of this application. The direction indicated by the arrowed indicator line in Figure 7 is the current distribution of the first antenna at a certain time period.

[0045] Figure 8 is a schematic diagram of an antenna provided in one embodiment of this application. The direction indicated by the arrowed indicator line in Figure 8 is the current distribution of the first antenna at a certain time period.

[0046] Figure 9 is a schematic diagram of an antenna provided in one embodiment of this application. The direction indicated by the arrowed indicator line in Figure 9 is the current distribution of the first antenna at a certain time period.

[0047] Figure 10 is a schematic diagram of an antenna provided in one embodiment of this application. The direction indicated by the arrowed indicator line in Figure 10 is the current distribution of the first antenna at a certain time period.

[0048] Figure 11 is a schematic diagram of an antenna provided in one embodiment of this application. The direction indicated by the arrowed indicator line in Figure 11 is the current distribution of the second antenna at a certain time period.

[0049] Figure 12 is a schematic diagram of an antenna provided in one embodiment of this application;

[0050] Figure 13 is a schematic diagram of an antenna provided in one embodiment of this application;

[0051] Figure 14 is a schematic diagram of an antenna provided in one embodiment of this application;

[0052] Figure 15 is a schematic diagram of an antenna provided in one embodiment of this application;

[0053] Figure 16 is a schematic diagram of an antenna provided in one embodiment of this application;

[0054] Figure 17 is a schematic diagram of an antenna provided in one embodiment of this application;

[0055] Figures 18A and 18B are schematic diagrams of an antenna provided in one embodiment of this application. Figure 18A includes the current distribution of the first antenna. The direction indicated by the arrow in Figure 18A is the current distribution of the first antenna at a certain time period.

[0056] Figures 19A and 19B are schematic diagrams of an antenna provided in one embodiment of this application. Figure 19A includes the current distribution of the first antenna. The direction indicated by the arrow in Figure 19A is the current distribution of the first antenna at a certain time period.

[0057] Figure 20 is a schematic diagram of an antenna provided in one embodiment of this application;

[0058] Figure 21 is a schematic diagram of an antenna provided in one embodiment of this application;

[0059] Figures 22A and 22B are schematic diagrams of an antenna provided in one embodiment of this application. Figure 22A includes the current distribution of the first antenna, and Figure 22B includes the current distribution of the second antenna.

[0060] Figures 23A and 23B are schematic diagrams of an antenna provided in one embodiment of this application. Figure 23A includes the current distribution of the first antenna, and Figure 23B includes the current distribution of the second antenna.

[0061] Figure 24 is a schematic diagram of the overall system efficiency and radiation efficiency of the first antenna in the embodiment provided in Figures 23A and 23B.

[0062] Figures 25A and 25B are schematic diagrams of an antenna provided in one embodiment of this application. Figure 25A includes the current distribution of the first antenna, and Figure 25B includes the current distribution of the second antenna.

[0063] Figure 26A is a schematic diagram of an antenna provided in one embodiment of this application;

[0064] Figure 26B is a schematic diagram of the S77 curve of the antenna provided in the embodiment shown in Figure 26A;

[0065] Figure 26C is a schematic diagram of the overall system efficiency and radiation efficiency curves of the first antenna in the embodiment shown in Figure 26A.

[0066] Figure 26D is a schematic diagram of the overall system efficiency and radiation efficiency curves of the second antenna in the embodiment shown in Figure 26A. Curve SE represents the overall system efficiency of the second antenna, and curve RE represents the radiation efficiency of the second antenna. Detailed Implementation

[0067] Explanation of some terms

[0068] Radiator (or antenna stub): This is the device in an antenna used to receive / transmit electromagnetic wave radiation. In some cases, the term "antenna" in a narrow sense refers to the radiator (or antenna stub), 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 (or antenna stub) via a feed line. The radiator (or antenna stub) converts this energy into electromagnetic wave energy of a specific polarization and radiates it in the desired direction. The receiving radiator (or antenna stub) 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.

[0069] Radiators (or antenna stubs) may include conductors with specific shapes and sizes, such as wires or sheets, and this application does not limit the specific shape. In one embodiment, a linear radiator (or antenna stub) may be simply referred to as a wire antenna. In one embodiment, a linear radiator may be implemented by a conductive frame, and may also be referred to as a frame antenna. In one embodiment, a linear radiator (or antenna stub) may be implemented by a support conductor, and may also be referred to as a support antenna. In one embodiment, the diameter (e.g., including thickness and width) of the linear radiator, or the radiator of the wire antenna, is much smaller than the wavelength (e.g., the wavelength of the medium) (e.g., less than 1 / 16 of the wavelength), and the length may be comparable to the wavelength (e.g., the wavelength of the medium) (e.g., a length of approximately 1 / 8 of the wavelength, or 1 / 8 to 1 / 4, or 1 / 4 to 1 / 2, or longer). The main forms of wire antennas include dipole antennas, half-wave dipole antennas, monopole antennas, loop antennas, inverted F antennas (also known as IFA, Inverted F Antenna), and planar inverted F antennas (also known as PIFA, Planar Inverted F Antenna). For example, in the case of a dipole antenna, each dipole antenna typically includes two radiating stubs, each of which is fed from the feed end of the radiating stub by a feed section. For example, an inverted-F antenna (IFA) can be considered as a monopole antenna with an added ground path. An IFA antenna has one feed point and one ground point, and is called an inverted-F antenna because its side view is inverted-F shaped. In one embodiment, the sheet radiator (or antenna stub) may include a microstrip antenna or a patch antenna. In one embodiment, the sheet radiator (or antenna stub) may be implemented using a planar conductor (e.g., a conductive sheet or conductive coating). In one embodiment, the sheet radiator (or antenna stub) may include a conductive sheet, such as a copper sheet. In one embodiment, the sheet radiator (or antenna stub) may include a conductive coating, such as silver paste. The shape of the sheet radiator includes circular, rectangular, and annular shapes, and this application does not limit the specific shape. A microstrip antenna typically consists of a dielectric substrate, a radiator (or antenna stub), and a ground plane, with the dielectric substrate positioned between the radiator (or antenna stub) and the ground plane.

[0070] Radiators (or antenna stubs) may also include slots or gaps formed on a conductor, for example, closed or semi-closed slots or gaps formed on a grounded conductor surface. In one embodiment, a slotted or slit radiator may be simply referred to as a slot antenna or a gap antenna. In one embodiment, the radial dimension (e.g., including width) of the slot or gap of the slot antenna / gap antenna is much smaller than the wavelength (e.g., the dielectric wavelength) (e.g., less than 1 / 16 of the wavelength), while the length dimension may be comparable to the wavelength (e.g., the dielectric wavelength) (e.g., a length of approximately 1 / 8 of the wavelength, or 1 / 8 to 1 / 4, or 1 / 4 to 1 / 2, or longer). In one embodiment, a radiator with a closed slot or gap may be simply referred to as a closed slot antenna. In one embodiment, a radiator with a semi-closed slot or gap (e.g., an opening added to a closed slot or gap) may be simply referred to as an open slot antenna. In some embodiments, the gap shape is elongated. In some embodiments, the length of the gap is approximately half a wavelength (e.g., the dielectric wavelength). In some embodiments, the length of the gap is approximately an integer multiple of a wavelength (e.g., one dielectric wavelength). In some embodiments, the slot can be fed by transmission lines connected across one or both sides, thereby exciting a radio frequency electromagnetic field on the slot and radiating electromagnetic waves into space. In one embodiment, the radiator of the slot antenna or gap antenna can be implemented by a conductive frame grounded at both ends, also known as a frame antenna; in this embodiment, the slot antenna or gap antenna can be viewed as including a linear radiator, the linear radiator being spaced apart from the ground and grounded at both ends, thereby forming a closed or semi-closed slot or gap. In one embodiment, the radiator of the slot antenna or gap antenna can be implemented by a support conductor grounded at both ends, also known as a support antenna.

[0071] A feed power supply / feed circuit is a combination of all circuits used for receiving and transmitting radio frequency (RF) signals. A feed circuit may include a transceiver and an RF front-end. In some cases, the term "feed circuit" is narrowly interpreted as an RF IC (Radio Frequency Integrated Circuit), which can be considered to include both the RF front-end chip and the transceiver. The feed circuit has the function of converting radio waves (e.g., RF signals) into electrical signals (e.g., digital signals). It is generally considered part of the RF component. The feed circuit may include a transmit path and a receive path to realize the RF signal transmission and reception functions of the antenna system. The antenna system in the terminal device provided in this application includes a feed source and at least two antennas, and the feed circuit includes a transmit path and at least two sets of receive paths.

[0072] In some embodiments, the electronic device may also include a test socket (or, RF socket or RF test socket). This test socket can be used to insert a coaxial cable to test the characteristics of the RF front-end circuitry or the radiator of the antenna. The RF front-end circuitry can be considered as the circuitry coupled between the test socket and the transceiver.

[0073] In some embodiments, the radio frequency front-end circuit can be integrated into a radio frequency front-end chip in an electronic device, or the radio frequency front-end circuit and the transceiver can be integrated into a radio frequency chip in an electronic device.

[0074] It should be understood that any two feed circuits in the first / second / ...Nth feed circuit of this application can share the same transceiver, for example, by transmitting signals through a radio frequency channel (e.g., a port (pin) of a radio frequency chip) in a transceiver; they can also share a radio frequency front-end circuit, for example, by processing signals through a switch or amplifier in a radio frequency front-end.

[0075] It should also be understood that the two feed circuits in the first / second / ...Nth feed circuit of this application typically correspond to two RF test sockets in an electronic device.

[0076] Ground / Plug: This can broadly refer to at least a portion of any grounding layer, ground plane, or grounding metal layer within an electronic device (such as a mobile phone), or at least a portion of any combination of the aforementioned grounding layers, ground planes, or grounding components. "Ground / Plug" can be used for grounding components within an electronic device. In one embodiment, "Ground / Plug" may include any one or more of the following: a grounding layer of a circuit board of an electronic device, a ground plane formed by the frame of the electronic device, a grounding metal layer formed by a thin metal film beneath the screen, a conductive grounding layer of a battery, and conductive or metallic components electrically connected to the aforementioned grounding layer / ground plane / metal layer. In one embodiment, the circuit board may be a printed circuit board (PCB), such as an 8-layer, 10-layer, or 12-14-layer board having 8, 10, 12, 13, or 14 layers of conductive material, or components separated and electrically insulated by dielectric or insulating layers such as glass fiber or polymers. In one embodiment, the circuit board includes a dielectric substrate, a grounding layer, and a trace layer, with the trace layer and grounding layer electrically connected via vias. In one embodiment, components such as display 120, touch screen, input buttons, transmitter, processor, memory, battery 140, charging circuit, system-on-chip (SoC) architecture, etc., may be mounted on or connected to the circuit board; or electrically connected to the trace layers and / or ground layers in the circuit board. For example, an RF source is disposed on a trace layer.

[0077] Any of the aforementioned grounding layers, ground planes, or grounding metal layers are made of conductive materials. In one embodiment, the conductive material may be any of the following: copper, aluminum, stainless steel, brass and their alloys, copper foil on an insulating substrate, aluminum foil on an insulating substrate, gold foil on an insulating substrate, silver-plated copper, silver-plated copper foil on an insulating substrate, silver foil on an insulating substrate and tin-plated copper, graphite-impregnated cloth, graphite-coated substrates, copper-plated substrates, brass-plated substrates, and aluminum-plated substrates. Those skilled in the art will understand that grounding layers / ground planes / grounding metal layers may also be made of other conductive materials.

[0078] Grounding: refers to coupling with the aforementioned ground / floor via a grounding structure and / or grounding circuit. In one embodiment, grounding can be achieved through physical grounding, such as through a structural component of the mid-frame to achieve physical grounding at a specific location on the frame (or, physical ground). In another embodiment, grounding can be achieved through device grounding, such as through devices like capacitors / inductors / resistors connected in series or parallel (or, device ground).

[0079] Capacitor: can be understood as lumped capacitance and / or distributed capacitance. Lumped capacitance refers to capacitive components, such as capacitor elements; distributed capacitance (or distributed capacitance) refers to the equivalent capacitance formed by two conductive components separated by a certain gap.

[0080] Inductance: can be understood as lumped inductance and / or distributed inductance. Lumped inductance refers to components that exhibit inductance, such as capacitors; distributed inductance (or distributed inductance) refers to the equivalent inductance formed through a conductive element of a certain length, such as the equivalent inductance formed by a conductor due to bending or rotation.

[0081] Resonance / Resonant Frequency: The resonant frequency is also called the resonance frequency. The resonant frequency can have a frequency range, that is, the frequency range where resonance occurs. The resonant frequency can be a frequency range where the return loss characteristic is less than -6dB. The frequency corresponding to the strongest resonance point is the center frequency. The return loss characteristic of the center frequency can be less than -20dB. It should be understood that, unless otherwise specified, in the phrase "generating the first resonance" mentioned in this application, the first resonance should be the fundamental mode resonance generated by the antenna / radiator, or the lowest frequency resonance generated by the antenna / radiator in a certain antenna mode. It should be understood that the antenna / radiator can generate one or more antenna modes according to a specific design, and each antenna mode can correspond to a fundamental mode resonance.

[0082] Resonant frequency band: The range of resonant frequencies is the resonant frequency band. The return loss characteristics at any frequency point within the resonant frequency band can be less than -6dB or -5dB.

[0083] Communication band / operating 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, the antenna's operating band includes the B40 band. The frequency range that meets the specifications can be considered the antenna's operating band.

[0084] The resonant frequency band and the operating frequency band may be the same or different, or their frequency ranges may partially overlap. In one embodiment, one or more resonant frequency bands of the antenna may cover one or more operating frequency bands of the antenna.

[0085] Electrical length: can be the ratio of physical length (i.e., mechanical length or geometric length) to the wavelength of the transmitted electromagnetic wave. Electrical length can satisfy the following formula:

[0086] Where L is the physical length and λ is the wavelength of the electromagnetic wave.

[0087] Wavelength: or operating wavelength, can be the wavelength corresponding to the center frequency of the resonant frequency or the center frequency of the operating frequency band supported by the antenna. For example, assuming the center frequency of the B1 uplink band (resonant frequency from 1920MHz to 1980MHz) is 1955MHz, then the operating wavelength can be the wavelength calculated using this frequency. Not limited to the center frequency, "operating wavelength" can also refer to the wavelength corresponding to the non-center frequency of the resonant frequency or operating frequency band.

[0088] It should be understood that wavelength (operating wavelength) can be understood as the wavelength of an electromagnetic wave in a medium. For example, the wavelength of an electromagnetic wave generated by a radiator propagating in a medium and the wavelength propagating in a vacuum satisfy the following formula:

[0089] Wherein, λε is the wavelength of the electromagnetic wave in the medium, λc is the wavelength of the electromagnetic wave in vacuum, and εr is the relative permittivity of the medium in the dielectric layer. In the embodiments of this application, the wavelength typically refers to the dielectric wavelength, which can be the dielectric wavelength corresponding to the center frequency of the resonant frequency, or the dielectric wavelength corresponding to the center frequency of the operating frequency band supported by the antenna. For example, assuming the center frequency of the B1 uplink band (resonant frequency of 1920MHz to 1980MHz) is 1955MHz, the wavelength can be the dielectric wavelength calculated using this frequency. Not limited to the center frequency, the "dielectric wavelength" can also refer to the dielectric wavelength corresponding to the non-center frequency of the resonant frequency or operating frequency band. For ease of understanding, the dielectric wavelength mentioned in the embodiments of this application can be simply calculated using the relative permittivity of the dielectric filling one or more sides of the radiator.

[0090] Coupling can be understood as direct coupling and / or indirect coupling. "Coupled connection" can be understood as a direct coupling connection and / or indirect coupling connection. Direct coupling can also be called "electrical connection," which can be understood as physical contact and electrical conduction between components; it can also be understood as the form of connection between different components in a circuit structure through physical lines that can transmit electrical signals, such as copper foil or wires on a printed circuit board (PCB). "Indirect coupling" can be understood as electrical conduction between two conductors through a gap / non-contact method. In one embodiment, indirect coupling can also be called capacitive coupling, for example, signal transmission is achieved by forming an equivalent capacitance through coupling between the gaps between two conductive parts.

[0091] A matching circuit is a circuit associated with adjusting the radiation characteristics of an antenna. In one embodiment, the matching circuit is coupled between the feed circuit and the corresponding radiator. Typically, the matching circuit is coupled between the test mount and the radiator. In one embodiment, the matching circuit has impedance matching and / or frequency tuning functions. It is generally considered part of the antenna.

[0092] A tuning circuit is a circuit associated with adjusting the resonant frequency of an antenna. In one embodiment, the tuning circuit is coupled between the radiator and the ground. In another embodiment, the tuning circuit is coupled between the feed circuit and the radiator. In yet another embodiment, the tuning circuit functions as impedance matching and / or frequency tuning. Typically, it is considered part of the antenna.

[0093] In one embodiment, the matching circuit / tuning circuit may include switches and / or electronic components / devices, where the switches are electronic components / devices for switching the coupling connection of the radiator. The switches in the matching circuit / tuning circuit may also be referred to as antenna switches. In one embodiment, the matching circuit / tuning circuit may include a filter circuit.

[0094] The grounding / feeding structure may include connectors, such as metal springs, and the radiator is coupled to the ground / feeding circuit via the grounding structure. In some embodiments, the feeding structure may include a transmission line / feeding wire, and the grounding structure may include a grounding wire.

[0095] A feed line, also called a transmission line, is the connection line between the transceiver of an antenna and the radiator. Transmission lines can transmit current waves or electromagnetic waves directly, depending on the frequency and type. The connection point on the radiator where the transmission line connects is usually called the feed point. Transmission lines include conductive transmission lines, coaxial transmission lines, waveguides, and microstrip lines. Depending on their implementation, transmission lines can include antenna frames or glass antenna frames. Depending on the carrier, transmission lines can be implemented using LCP (Liquid Crystal Polymer), FPC (Flexible Printed Circuit), or PCB (Printed Circuit Board).

[0096] End / Point: The term "end / point" in the context of the antenna radiator's first end / second end / feed end / ground end / feed point / ground point / connection point should not be narrowly interpreted as an endpoint or end that is physically disconnected from other radiators. It can also be considered as a point or segment on a continuous radiator. In one embodiment, "end / point" may include a connection / coupling region on the antenna radiator that is coupled to other conductive structures. For example, a feed end / feed point may 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 / ground point may be a connection / coupling region on the antenna radiator that is coupled to a ground structure.

[0097] Open terminal, closed terminal: In some embodiments, open terminal and closed terminal are, for example, relative to whether or not they are grounded; the closed terminal is grounded, and the open terminal is not grounded. In some embodiments, open terminal and closed terminal are, for example, relative to other conductors; the closed terminal is electrically connected to other conductors, and the open terminal is not electrically connected to other conductors. In one embodiment, the open terminal may also be referred to as a floating terminal, free terminal, open terminal, or open-circuit terminal. In one embodiment, the closed terminal may also be referred to as a ground terminal or 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).

[0098] 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., capacitors, inductors, etc.) through a closed end can maintain the current distribution characteristics of the point of high current / low electric field. In one embodiment, opening a slit at or near the closed end (e.g., filling the slit with insulating material) can maintain the current distribution characteristics of the point of high current / low electric field.

[0099] 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., capacitors, inductors, etc.) through an open terminal can maintain the current distribution characteristics of the point with a small current or a large electric field.

[0100] 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.

[0101] The current unidirectional / reverse distribution mentioned in the embodiments of this application should be understood as the main currents on conductors on the same side being in the same / reverse direction. For example, when a unidirectional current is excited on a bent or looped conductor (e.g., the current path is also bent or looped), it should be understood that, for example, the main currents excited on the conductors on both sides of a looped conductor (e.g., on the conductors on both sides of a gap) are in opposite directions, but still fall under the definition of unidirectional current in this application. In one embodiment, unidirectional current on a conductor can mean that the current on that conductor has no reversal point. In one embodiment, reversible current on a conductor can mean that the current on that conductor has at least one reversal point. In one embodiment, unidirectional current on two conductors can mean that the currents on both conductors have no reversal points and flow in the same direction. In one embodiment, reversible current on two conductors can mean that the currents on both conductors have no reversal points and flow in opposite directions. The unidirectional / reverse current on multiple conductors can be understood accordingly.

[0102] The terms "middle" or "middle position" mentioned in the embodiments of this application refer to certain ranges or distances. For example, the middle (position) of a conductor can be a section of the conductor including the midpoint, or the middle (position) of a conductor can be a section of the conductor that is less than a predetermined threshold (e.g., 1 mm, 2 mm, or 2.5 mm) from the midpoint.

[0103] Antenna system efficiency (total efficiency): refers to the ratio of input power to output power at the antenna port.

[0104] Antenna radiation efficiency refers to the ratio of the power radiated into space by an antenna (i.e., the power effectively converted into electromagnetic waves) to the active power input to the antenna. Active power input to the antenna = antenna input power - loss power; loss power mainly includes return loss power and ohmic loss power of metals and / or dielectric loss power. Radiation efficiency is a measure of an antenna's radiation capability; metal loss and dielectric loss are both factors affecting radiation efficiency.

[0105] Those skilled in the art will understand that efficiency is generally expressed as a percentage, and there is a corresponding conversion relationship between it and dB. The closer the efficiency is to 0dB, the better the efficiency of the antenna.

[0106] 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.

[0107] 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. The S11 parameter is usually negative. The smaller the S11 parameter, the smaller the antenna return loss, the less energy the antenna reflects back, meaning more energy actually enters the antenna, and the higher the antenna's system efficiency. Conversely, the larger the S11 parameter, the greater the antenna return loss, and the lower the antenna's system efficiency. It should be noted that in engineering, an S11 value of -6dB is generally used as a standard. When the antenna's S11 value is less than -6dB, the antenna can be considered to be operating normally, or its transmission efficiency can be considered to be good.

[0108] Parallelism: The parallelism defined in this application is not limited to absolute parallelism. This definition of parallelism can be understood as basic parallelism. It allows for situations where the parallelism is not absolute due to factors such as assembly tolerance, design tolerance, and structural flatness. It also allows for errors within a small angular range, such as within 10 degrees of assembly error. These can all be considered as parallel relationships.

[0109] Perpendicularity: The perpendicularity defined in this application is not limited to an absolute perpendicular intersection (with an included angle of 90 degrees). It is permissible for non-absolute perpendicular intersections caused by factors such as assembly tolerances, design tolerances, and structural flatness. It is permissible for errors within a small angular range, such as an assembly error range of 80 to 100 degrees, which can all be understood as a perpendicular relationship.

[0110] The terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.

[0111] The possible embodiments of this application are described below with reference to the accompanying drawings.

[0112] The antenna provided in this specific embodiment is used in a terminal device to achieve the transmission and reception of communication signals. The terminal device can be, but is not limited to, devices such as mobile phones, tablets, and laptops, or wearable devices such as watches.

[0113] Figure 1 is a schematic diagram of a terminal device provided in one embodiment of this application. Referring to Figure 1, the terminal device 100 is a smartphone and also a tablet. The terminal device 100 includes a frame 10, an antenna 20, and a radio frequency chip 30.

[0114] In one embodiment, the terminal device 100 includes a back cover, a display screen, and a frame 10 connected between the back cover and the display screen. The frame 10 is independent of the back cover and assembled between the back cover and the display screen. In another embodiment, the frame 10 may also be part of the back cover, and the frame 10 may be integrally formed with the back cover. The antenna 20 includes a feed structure 21 and a radiator 22. In one embodiment, the frame 10 is made of a conductive material, such as metal. The radiator 22 is integrated onto the frame 10, that is, a portion of the frame 10 constitutes the radiator 22. In another embodiment, the frame 10 may also be made of a non-conductive material, and the radiator 22 may be a conductive structure connected to the frame 10; alternatively, the radiator 22 may also be formed onto the frame 10 using laser direct forming (LDS) technology. In the embodiment shown in FIG1, the radiator 22 of the antenna 20 is disposed at the bottom of the terminal device 100.

[0115] The radio frequency (RF) chip 30 is located inside the terminal device 100 and can be mounted on the main board or sub-board of the terminal device 100. The RF chip 30 is electrically connected to the power supply structure 21, for example, through an RF line to connect the RF chip 30 and the power supply structure 21, thereby enabling the transmission of RF signals. In one embodiment, the power supply structure 21 and the RF chip 30 can be mounted on the same circuit board, allowing for electrical connection between the RF chip 30 and the power supply structure 21 through traces within the circuit board. In other embodiments, the RF chip 30 and the power supply structure 21 can be mounted on different circuit boards and connected through transmission lines within the terminal device, such as an FPC.

[0116] Figure 2 is a schematic diagram of a terminal device provided in one embodiment of this application. Referring to Figure 2, the terminal device 100 is a foldable device, such as a foldable smartphone. The term "foldable device" as used herein refers to a device capable of being folded and unfolded, and a terminal device that remains in a folded or unfolded state. In one embodiment, the terminal device has a smaller display interface and overall smaller size in its folded state, making it easy to carry; in its unfolded state, the terminal device has a larger display interface. In the embodiment shown in Figure 2, the terminal device 100 includes a frame 10, an antenna 20, and an RF chip 30. The radiator 22 of the antenna 20 is disposed on the frame 10, and the radiator 22 can be disposed at the bottom of the frame 10, or at the side or top of the frame 10. The feed structure 21 of the antenna 20 is electrically connected to the RF chip 30. In this solution, the terminal device 100 has a main screen and a sub-screen capable of being folded and unfolded relative to each other, and a hinge connecting the main screen and the sub-screen. The RF chip 30 and the power supply structure 21 can be located on the same side of the hinge, for example, both the RF chip 30 and the power supply structure 21 can be located on one side of the main screen. Alternatively, the RF chip 30 and the power supply structure 21 can be distributed on both sides of the hinge, for example, the RF chip 30 can be located on one side of the main screen and the power supply structure 21 can be located on one side of the secondary screen.

[0117] Figure 3 is a schematic diagram of a terminal device provided in one embodiment of this application. Referring to Figure 2, the terminal device 100 is a tablet computer. The terminal device 100 includes a frame 10, an antenna 20, and an RF chip 30. The radiator 22 of the antenna 20 is disposed on the frame 10, and the radiator 22 can be disposed on the side of the frame 10. The feeding structure 21 of the antenna 20 is electrically connected to the RF chip 30.

[0118] Figure 4 is a schematic diagram of the hardware architecture of an antenna system in a terminal device according to one embodiment of this application. In one embodiment, the antenna system includes a baseband chip, a transceiver (also called an RF transceiver unit), an RF front-end chip, a matching circuit, and radiators. In one embodiment, the antenna system may further include an RF socket, which is disposed between the RF front-end chip and the matching circuit; the RF socket may also be called an RF test socket. In the embodiment shown in Figure 4, there are two radiators. This can be understood as the antenna system provided by this solution employing diversity technology, where one radiator is the radiator of the main antenna and the other is the radiator of the diversity antenna, and each radiator is coupled to a matching circuit. The matching circuit can be used to achieve impedance matching of the signals transmitted and received by the radiators. The matching circuit can also be used to match the resonant frequency band of the RF signal.

[0119] In one embodiment, the RF front-end chip can be the RF chip shown in the embodiments of Figures 1, 2, and 3. In the embodiment shown in Figure 4, the RF front-end chip includes a transmit path, a receive path, and a switching component. It should be understood that Figure 4 only shows the RF front-end chip architecture of one embodiment; in other embodiments, the RF front-end chip may have other architectures. The transmit path includes a power amplifier, a duplexer, and a switch; the receive path includes a low-noise amplifier, a filter, and a switch. In one embodiment, the switching component includes a circuit-side-cut TAS (Transmit Antenna Selection) switch, an antenna tuning switch, etc. In one embodiment, the matching circuit may further include one or more of the following: a circuit with tuning function, a circuit with filtering function, and a switching circuit.

[0120] In Figure 4, the arrows on the signal transmission lines indicate the direction of signal flow. The signal interaction between the baseband chip and the transceiver is bidirectional. The transceiver receives communication signals from the baseband chip and transmits them to the transmission path. In the transmission path, the communication signal passes sequentially through a power amplifier, a duplexer, and a switch. After exiting the transmission path, the signal passes through the switching assembly and is then transmitted to the RF socket. The RF socket and the matching circuit are coupled, and their signal interaction is also bidirectional. The communication signal is transmitted to the radiator after passing through the matching circuit. The communication signal received by the radiator can be transmitted to the RF socket after passing through the matching circuit, and then from the RF socket to the RF front-end chip. After passing through the switching assembly, the communication signal enters the receiving path, where it passes sequentially through a switch, a filter, and a low-noise amplifier. The transceiver receives the communication signal and then transmits it to the baseband chip.

[0121] In one embodiment, the RF front-end chip has multiple independent RF paths, for example, one transmit path and two receive paths. In other embodiments, the RF front-end chip may include one or more transmit paths and one or more receive paths, etc.

[0122] Figures 5A and 5B are schematic diagrams of an antenna provided in one embodiment of this application. Figure 5A shows the current distribution of a first antenna, and the direction indicated by the arrow in Figure 5A is the current distribution of the first antenna at a certain time period. Figure 5B shows the current distribution of a second antenna, and the direction indicated by the arrow in Figure 5B is the current distribution of the second antenna at a certain time period.

[0123] Referring to Figures 5A and 5B, in one embodiment, antenna 20 includes a first stub 23 (i.e., stub AB), a second stub 24 (i.e., stub CD), an inductive structure 25, and a capacitive structure 26. Antenna reconfiguration can be achieved through coupling between the first stub 23, the second stub 24, the inductive structure 25, and the capacitive structure 26. The radiator of the first antenna is constructed through the coupling between the inductive structure 25 and the first stub 23 and the second stub 24. The radiator of the second antenna is constructed through the coupling between the capacitive structure 26 and the first stub 23 and the second stub 24. The resonant ranges of the first antenna and the second antenna are different. The first antenna is used to generate a first resonance. The second antenna is used to generate a second resonance. In one embodiment, the first antenna is a low-to-medium frequency antenna, and the second antenna is a mid-to-high frequency antenna. For example, in one embodiment, the frequency band of the first resonance includes, but is not limited to, at least one communication frequency band in the frequency range of 698MHz-960MHz; the frequency band of the second resonance includes, but is not limited to, at least one communication frequency band in the frequency range of 1700MHz-2700MHz. The antenna provided in this application embodiment can also be reconstructed into a third antenna, a fourth antenna, etc. In other words, an antenna provided in one embodiment may include multiple antennas and is not limited to the first antenna and the second antenna.

[0124] The embodiments of this application utilize the radiating part formed by the first branch 23 and the second branch 24 in combination with the inductive structure 25 and the capacitive structure 26 to realize the arrangement of antennas in at least two different resonant frequency bands. Through radiator reconstruction, two or more antennas can be arranged in a limited space, saving the space occupied by antennas in the terminal device. For the terminal device, it can accommodate more antennas and improve the radio frequency transceiver performance of the terminal device.

[0125] One end of the first branch 23 is an open-circuit terminal A, and the other end is a first coupling terminal B. One end of the second branch 24 is a second coupling terminal C, and the other end is a ground terminal D. The second branch 24 is located on one side of the electrical length extension direction of the first branch 23. The second coupling terminal C of the second branch 24 is adjacent to the first coupling terminal B of the first branch 23, and a gap is formed between the first coupling terminal B and the second coupling terminal C.

[0126] In one embodiment, the sum of the electrical length of the first stub 23 and the electrical length of the second stub 24 is less than one-quarter of the wavelength corresponding to the resonant frequency of the first resonance.

[0127] In one embodiment, the sum of the electrical length of the first stub 23 and the electrical length of the second stub 24 is greater than one-quarter of the wavelength corresponding to the resonant frequency of the second resonance.

[0128] In one embodiment, the first branch 23, the second branch 24, and the inductive structure 25 are coupled together to form the resonant mode of the first antenna, generating a first resonance.

[0129] In one embodiment, the first branch 23, the second branch 24, and the capacitive structure 26 are coupled together to form the resonant mode of the second antenna, generating a second resonance.

[0130] The first stub 23 and the second stub 24 form the main radiating part of the antenna. The inductive structure 25 and the main radiating part together constitute the radiator of the first antenna. The capacitive structure 26 and the main radiating part (the first stub 23 and the second stub 24) together constitute the radiator of the second antenna. In this embodiment, by setting a gap between the first stub 23 and the second stub 24, and by setting the sum of the electrical lengths of the first stub 23 and the second stub 24 to be less than one-quarter of the wavelength corresponding to the resonant point of the first resonance and less than one-quarter of the wavelength corresponding to the resonant point of the second resonance, the electrical length of the radiator of the first antenna can satisfy one-quarter of the wavelength corresponding to the resonant point frequency of the first antenna; and the electrical length of the radiator of the second antenna can also satisfy one-quarter of the wavelength corresponding to the resonant point frequency of the second antenna.

[0131] In this embodiment, the inductive structure 25 and the capacitive structure 26 enable the antenna 20 to construct the radiator of the first antenna and the radiator of the second antenna. This allows for antenna reconfiguration by reusing antenna stubs within a limited space. The first antenna and the second antenna can be configured at the same position on the frame, saving space on the frame of the terminal device.

[0132] In one embodiment, the first segment 23 and the second segment 24 form part of the frame of the terminal device. The frame of the terminal device is made of metal, and the first segment 23 and the second segment 24 are constructed by creating slits in the frame. Since the frame of the terminal device needs to accommodate many antennas, using the same segment of the frame to arrange antenna radiators within a limited space allows for the arrangement of at least two antennas, improving the antenna integration of the terminal device and saving space.

[0133] In one embodiment, the frame of the terminal device forms a rectangular outline, with a portion of the frame forming the top edge, a portion forming the bottom edge, and a portion forming the side edge. In one embodiment, the first branch 23 and the second branch 24 are formed on the bottom or top edge of the terminal device, and both the first branch 23 and the second branch 24 extend in the width direction of the terminal device. In one embodiment, the first branch 23 and the second branch 24 can also be distributed on the side edge of the terminal device, and both the first branch 23 and the second branch 24 extend in the length direction of the terminal device. In one embodiment, the first branch 23 and the second branch 24 can be distributed on the bottom edge and the side edge (or the top edge and the side edge), with a portion of the radiating portion formed by the first branch 23 and the second branch 24 located on the side edge and a portion located on the bottom edge (or the top edge). In one embodiment, the radiating portion formed by the first branch 23 and the second branch 24 is generally linear. In one embodiment, the radiating portion formed by the first branch 23 and the second branch 24 has an overall shape close to an L-shape. In one embodiment, the overall shape of the radiating portion formed by the first branch 23 and the second branch 24 is close to U-shaped.

[0134] Referring to Figures 5A and 5B, the inductive structure 25 is coupled between the first branch 23 and the second branch 24. The inductive structure 25 is either a lumped inductor or a distributed inductor. The antenna provided in this embodiment can flexibly select various inductive structure configurations, enabling the antenna to have more application scenarios. One end of the inductive structure 25 is coupled to the first branch 23, and the other end is coupled to the second branch 24. In one embodiment, the inductive structure 25 and the first branch 23 are coupled at a first position M1, which is close to the first coupling end B of the first branch 23. This can be understood as the distance between the first position M1 and the first coupling end B being less than the distance between the first position M1 and the open-circuit end A of the first branch 23. The inductive structure 25 and the second branch 24 are coupled at a second position M2, which is close to the second coupling end C of the second branch 24. This can be understood as the distance between the second position M2 and the second coupling end C being less than the distance between the second position M2 and the ground end D of the second branch 24.

[0135] In other embodiments, the first position M1 can be located at the first coupling terminal B, the open terminal A of the first branch 23, or other positions on the first branch 23. The second position M2 can be located at the second coupling terminal C, the ground terminal D of the second branch 24, or other positions on the second branch 24.

[0136] Referring to Figures 5A and 5B, a capacitive structure 26 is coupled between a first branch 23 and a second branch 24. The capacitive structure 26 is a lumped capacitor or a distributed capacitor. One end of the capacitive structure 26 is coupled to the first branch 23, and the other end is coupled to the second branch 24. In one embodiment, the coupling connection between the capacitive structure 26 and the first branch 23 is located near the first coupling end B. In another embodiment, the coupling connection between the capacitive structure 26 and the second branch 24 is located near the second coupling end C. In yet another embodiment, the coupling connection between the capacitive structure 26 and the first branch 23 is located at a first position M1, and the coupling connection between the capacitive structure 26 and the second branch 24 is located at a second position M2. The first position M1 and the second position M2 can simultaneously couple the inductive structure 25 and the capacitive structure 26.

[0137] In other embodiments, the capacitive structure 26 may also be coupled between the first coupling end B and the second coupling end C.

[0138] In one embodiment, the capacitance of the capacitive structure 26 is adjustable; for example, the capacitive structure 26 includes a variable capacitor. This solution, by setting the capacitive structure 26 to an adjustable capacitance architecture, makes it easier to tune the second antenna. In other embodiments, the capacitive structure 26 can also be a capacitor with a fixed capacitance or a distributed capacitor. The antenna provided in this application embodiment can flexibly select various capacitive structure settings, making the antenna suitable for more application scenarios. The capacitive structure 26 is used to control the tuning of the second antenna. Since the capacitive structure 26 is located at the gap between the first stub 23 and the second stub 24, this location is a weak point in the electric field, and the first antenna is not sensitive to the adjustment of the effective capacitance value of the capacitive structure 26. Therefore, the adjustment of the effective capacitance value of the capacitive structure 26 has a small impact on the first antenna.

[0139] Referring to Figures 5A and 5B, the antenna 20 further includes a first feed structure 211 and a second feed structure 212, and the second branch 24 has a first feed point E and a second feed point F. In one embodiment, along the extension direction of the second branch 24, the ground terminal D, the first feed point E, the second feed point F, and the second coupling terminal C are arranged sequentially at intervals. The first feed structure 211 and the first feed point E are coupled together and used to feed signals in a first frequency band, and the second feed structure 212 and the second feed point F are coupled together and used to feed signals in a second frequency band. The first resonance corresponds to the signal in the first frequency band, and the second resonance corresponds to the signal in the second frequency band.

[0140] In other embodiments, the positions of the first feed point E and the second feed point F on the second stub 24 can be interchanged. The antenna 20 provided in this application embodiment does not limit the specific positions of the first feed point E and the second feed point F on the second stub 24.

[0141] In one embodiment, the first feed point E is matched with: a series capacitor structure (effective capacitance value of 1.5pF), a parallel inductive structure (effective inductance value of 3nH), a series capacitor structure (effective capacitance value of 2pF), and an inductive structure (effective inductance value of 4nH).

[0142] In one embodiment, the second feed point F is matched as follows: a parallel capacitor structure (effective capacitance value of 10pF), a series capacitor structure (effective capacitance value of 2.5pF), and a series inductive structure (effective inductance value of 10nH).

[0143] In one embodiment, the physical length of the first branch 23 is 21 mm, the physical length of the second branch 24 is 11 mm, the physical length between the second feed point F and the grounding terminal D of the second branch 24 is 4.7 mm, and the physical length between the first feed point E and the grounding terminal D of the second branch 24 is 2.8 mm.

[0144] The first feed structure 211 is coupled to the radio frequency chip in the terminal device. The first feed structure 211 transmits the feed signal to the first feed point E, which excites the antenna to generate the current of the first antenna. The current distribution shown in Figure 5A is a schematic diagram of the current distribution of the first antenna. The current flows from the ground terminal D of the second branch 24 to the position (second position M2) where the inductive structure 25 and the second branch 24 are coupled. The current passes through the inductive structure 25 and flows from the coupling connection position (first position M1) between the inductive structure 25 and the first branch 23 to the open terminal A of the first branch 23.

[0145] Since the first branch 23 and the second branch 24 are connected by the inductive structure 25, the gap between the first branch 23 and the second branch 24 is a weak point in the electric field because the inductive structure 25 carries current. Therefore, for the first antenna, the gap between the first coupling end B and the second coupling end C is a weak point in the electric field.

[0146] The second feeding structure 212 is coupled to the radio frequency chip in the terminal device. The second feeding structure 212 transmits the feeding signal to the second feeding point F, which excites the antenna to generate the current of the second antenna. The current distribution shown in Figure 5B is a schematic diagram of the current distribution of the second antenna. The current flows from the ground terminal D of the second branch 24 to the position where the capacitive structure 26 and the second branch 24 are coupled (second position M2). The current passes through the capacitive structure 26 and flows from the coupling connection position of the capacitive structure 26 and the first branch 23 (first position M1) to the open terminal A of the first branch 23.

[0147] In one embodiment, the effective inductance of the inductive structure 25 ranges from 3nH to 10nH. Constraining the effective inductance of the inductive structure 25 within the range of 3nH or greater and 10nH or less ensures that the inductive structure has a minimal impact on the second antenna, thus contributing to the performance of the second antenna. If the inductive structure 25 has an inductance less than 3nH, its impact on the second antenna is significant.

[0148] Figure 5C is a schematic diagram showing the overall system efficiency and radiation efficiency of the second antenna in the antenna provided by the embodiments shown in Figures 5A and 5B. In Figure 5C, the dashed line represents the radiation efficiency of the second antenna, and the solid line represents the overall system efficiency of the second antenna. In one embodiment, the capacitive structure 26 of the antenna provided by the embodiments shown in Figures 5A and 5B is an adjustable capacitor, and the inductance value of the inductive structure 25 is 5.6nH. Curve SE1 in Figure 5C represents the overall system efficiency of the second antenna when the capacitance value of the capacitive structure 26 is 2.2pF. Curve SE2 in Figure 5C represents the overall system efficiency of the second antenna when the capacitance value of the capacitive structure 26 is 1.5pF. Curve SE3 in Figure 5C represents the overall system efficiency of the second antenna when the capacitance value of the capacitive structure 26 is 1pF. Curve RE1 in Figure 5C represents the radiation efficiency of the second antenna when the capacitance value of the capacitive structure 26 is 2.2pF. Curve RE2 in Figure 5C represents the radiation efficiency of the second antenna when the capacitance value of the capacitive structure 26 is 1.5pF. Curve RE3 in Figure 5C represents the radiation efficiency of the second antenna under the condition that the capacitance of capacitive structure 26 is 1pF.

[0149] Referring to Figure 5C, in one embodiment of the antenna provided by this application, a change in the capacitance value of the capacitive structure 26 can cause a change in the resonant frequency of the second antenna. A smaller capacitance value of the capacitive structure 26 results in a higher resonant frequency for the second antenna. For example, the resonant frequency of the second antenna with a capacitance value of 1 pF is higher than the resonant frequency of the second antenna with a capacitance value of 2.2 pF. Although the capacitance value of the capacitive structure 26 is different, the radiation efficiency and overall system efficiency of the second antenna both meet the radiation performance requirements of the second antenna.

[0150] Figure 5D is a schematic diagram of the S11 curve of the second antenna provided in the embodiments shown in Figures 5A and 5B. In one embodiment, the capacitive structure 26 of the antenna provided in the embodiments shown in Figures 5A and 5B is an adjustable capacitor, and the inductance value of the inductive structure 25 is 5.6nH. Curve S11A in Figure 5D represents the return loss of the second antenna when the capacitance value of the capacitive structure 26 is 2.2pF. Curve S11B in Figure 5D represents the return loss of the second antenna when the capacitance value of the capacitive structure 26 is 1.5pF. Curve S11C in Figure 5D represents the return loss of the second antenna when the capacitance value of the capacitive structure 26 is 1pF. As can be seen from Figure 5D, the change in the capacitance value of the capacitive structure 26 can cause a change in the resonant frequency of the second antenna. A smaller capacitance value of the capacitive structure 26 results in a higher resonant frequency for the second antenna. Although the capacitance values ​​of the capacitive structure 26 are different, the return loss of the second antenna meets the radiation performance requirements of the second antenna.

[0151] Figure 5E is a schematic diagram of the S22 curve of the first antenna in the embodiment provided by Figures 5A and 5B. In one embodiment, the capacitive structure 26 of the antenna provided by the embodiment shown in Figures 5A and 5B is an adjustable capacitor, and the inductance value of the inductive structure 25 is 5.6nH. Curve S22A in Figure 5E represents the return loss of the first antenna when the capacitance value of the capacitive structure 26 is 2.2pF. Curve S22B in Figure 5E represents the return loss of the first antenna when the capacitance value of the capacitive structure 26 is 1.5pF. Curve S22C in Figure 5E represents the return loss of the first antenna when the capacitance value of the capacitive structure 26 is 1pF. As can be seen from Figure 5E, the first antenna has two resonance modes. In the first resonance mode, the resonant frequency of the first antenna is between 800MHz and 850MHz; in the second resonance mode, the resonant frequency of the first antenna is between 900MHz and 1030MHz. The change in the capacitance value of the capacitive structure 26 has little effect on the resonant frequency of the first antenna in the first resonance mode. The change in capacitance value of capacitive structure 26 will affect the second resonant frequency of the first antenna.

[0152] Figure 5F is a schematic diagram showing the system overall efficiency and radiation efficiency curves of the first antenna in the embodiments shown in Figures 5A and 5B. In Figure 5F, the dashed line represents the radiation efficiency of the first antenna, and the solid line represents the system overall efficiency of the first antenna. In one embodiment, the capacitive structure 26 of the antenna provided in the embodiments shown in Figures 5A and 5B is an adjustable capacitor, and the inductance value of the inductive structure 25 is 5.6nH. Curve SE1 in Figure 5F represents the system overall efficiency of the first antenna when the capacitance value of the capacitive structure 26 is 2.2pF. Curve SE2 in Figure 5F represents the system overall efficiency of the first antenna when the capacitance value of the capacitive structure 26 is 1.5pF. Curve SE3 in Figure 5F represents the system overall efficiency of the first antenna when the capacitance value of the capacitive structure 26 is 1pF. Curve RE1 in Figure 5F represents the radiation efficiency of the first antenna when the capacitance value of the capacitive structure 26 is 2.2pF. Curve RE2 in Figure 5F represents the radiation efficiency of the first antenna when the capacitance value of the capacitive structure 26 is 1.5pF. Curve RE3 in Figure 5F represents the radiation efficiency of the first antenna under the condition that the capacitance of capacitive structure 26 is 1pF.

[0153] Referring to Figure 5F, in one embodiment of the antenna provided by this application, the change in the capacitance value of the capacitive structure 26 has little effect on the frequency of a resonant mode of the first antenna. Although the capacitance value of the capacitive structure 26 is different, the radiation efficiency of the first antenna and the overall system efficiency both meet the radiation performance requirements of the first antenna.

[0154] Figure 6 is a schematic diagram of an antenna provided in one embodiment of this application. The direction indicated by the arrowed indicator line in Figure 6 is the current distribution of the first antenna during a certain period of time.

[0155] Referring to the embodiment shown in Figure 5A and Figure 6, in one embodiment, one end of the inductive structure 25 is coupled to the open terminal A of the first stub 23, and the other end of the inductive structure 25 is coupled to the second stub 24. In one embodiment, the inductive structure 25 can be a distributed inductor. In another embodiment, the inductive structure 25 can be a combination of a distributed inductor and a lumped inductor. The coupling connection position between the inductive structure 25 and the second stub 24 is the second position M2. The portion of the second stub 24 from the ground terminal D to the second position M, together with the inductive structure 25, constitutes the radiator of the first antenna. The sum of the electrical length of the second stub 24 from the ground terminal D to the second position M2 and the electrical length of the inductive structure 25 can satisfy one-quarter of the wavelength corresponding to the resonant frequency of the first resonance of the first antenna.

[0156] In the embodiment shown in Figure 6, the current of the first resonance of the first antenna excited by the first feed structure 211 flows through the inductive structure 25 in the region where the first stub 23 is located. The first stub 23 does not participate in the radiation of the first antenna. The first stub 23 is used to participate in the second resonance of the second antenna. The inductive structure 25 and the first stub 23 are coupled together, which is beneficial to the weak coupling between the inductive structure 25 and the first stub 23, and is beneficial to improving the radiation performance of the second antenna.

[0157] Figure 7 is a schematic diagram of an antenna provided in one embodiment of this application. The direction indicated by the arrowed indicator line in Figure 7 is the current distribution of the first antenna during a certain period of time.

[0158] Referring to the embodiment shown in Figure 5A and Figure 7, in one embodiment, one end of the inductive structure 25 is coupled to the middle position M3 of the first branch 23. In one embodiment, the middle position M3 can be understood as the midpoint of the physical length between the open terminal A and the first coupled terminal B. In another embodiment, the middle position M3 can be understood as a position within a region on the first branch 23, located in the middle region of the first branch 23, the distance of this region from the open terminal A being equal to the distance of this region from the first coupled terminal B, and the middle position M3 can be any position within this region. The other end of the inductive structure 25 is coupled to the second branch 24. In one embodiment, the inductive structure 25 can be a distributed inductor. In another embodiment, the inductive structure 25 can be a combination of a distributed inductor and a lumped inductor. The coupling connection between the inductive structure 25 and the first branch 23 is the middle position M3, and the coupling connection between the inductive structure 25 and the second branch 24 is the second position M2. The portion of the second branch 24 between the ground terminal D and the second position M2, the inductive structure 25, and the portion of the first branch 23 between the intermediate position M3 and the open terminal A of the first branch 23 together constitute the radiator of the first antenna. The sum of the electrical lengths of the second branch 24 between the ground terminal D and the second position M2, the inductive structure 25, and the intermediate position M3 to the open terminal A of the first branch 23 can satisfy the requirement that the resonant frequency of the first antenna corresponds to one-quarter of the wavelength.

[0159] In the embodiment shown in Figure 7, the current of the first resonance of the first antenna excited by the first feed structure 211 passes through the region between the open end A of the first stub 23 and the third position, the region between the second position on the inductive structure 25 and the ground end D on the second stub 24, and half of the region on the first stub 23 does not participate in the radiation of the first antenna. The portion of the first stub 23 from the third position to the first coupling end B is used to participate in the second resonance of the second antenna. Compared with the embodiment shown in Figure 5A, this is beneficial to reduce the coupling between the inductive structure 25 and the first stub 23, which is beneficial to improve the radiation performance of the second antenna.

[0160] Figure 8 is a schematic diagram of an antenna provided in one embodiment of this application. The direction indicated by the arrowed indicator line in Figure 8 is the current distribution of the first antenna during a certain period of time.

[0161] Referring to the embodiment shown in Figure 5A and Figure 8, in one embodiment, one end of the inductive structure 25 is coupled to the first coupling terminal B of the first stub 23, and the other end of the inductive structure 25 is coupled to the second coupling terminal C of the second stub 24. The first stub 23 from the open-circuit terminal A to the first coupling terminal B, the inductive structure 25, and the second stub 24 from the second coupling terminal C to the ground terminal D together constitute the radiator of the first antenna. The current distribution of the first resonance of the first antenna is: from the ground terminal D to the second coupling terminal C, the inductive structure 25, and from the first coupling terminal B to the open-circuit terminal A. In one embodiment, the first stub 23 and the second stub 24 are completely reused in the first antenna and the second antenna. The electrical length of the inductive structure 25 is smaller than that of the inductive structure 25 in the aforementioned embodiments, and the space occupied by the inductive structure 25 is also smaller. Therefore, it is beneficial to the miniaturization of the overall size of the antenna 20.

[0162] Figure 9 is a schematic diagram of an antenna provided in one embodiment of this application. The direction indicated by the arrowed indicator line in Figure 9 is the current distribution of the first antenna during a certain period of time.

[0163] Referring to the embodiment shown in Figure 5A and Figure 9, in one embodiment, one end of the inductive structure 25 is coupled to the first branch 23, and the other end of the inductive structure 25 is coupled to the middle position M4 of the second branch 24. In one embodiment, the middle position M4 can be understood as the midpoint of the physical length between the ground terminal D and the second coupling terminal C. In another embodiment, the middle position M4 can be understood as a location within a region on the second branch 24, located in the middle region of the second branch 24, where the distance from the ground terminal D is equal to the distance from the second coupling terminal C; the middle position M4 can be any location within this region. In one embodiment, the inductive structure 25 can be a distributed inductor. In yet another embodiment, the inductive structure 25 can be a combination of a distributed inductor and a lumped inductor. The coupling connection between the inductive structure 25 and the second branch 24 is the middle position M4, and the coupling connection between the inductive structure 25 and the first branch 23 is the first position M1. The portion of the first stub 23 from the open terminal A to the first position M1, the portion of the inductive structure 25 from the intermediate position M4 to the ground terminal D of the second stub 24, together constitute the radiator of the first antenna. The sum of the electrical lengths of the first stub 23 from the open terminal A to the first position M1, the inductive structure 25, and the intermediate position M4 to the ground terminal D of the second stub 24 can satisfy the requirement that the resonant frequency of the first antenna corresponds to one-quarter of the wavelength.

[0164] Figure 10 is a schematic diagram of an antenna provided in one embodiment of this application. The direction indicated by the arrowed indicator line in Figure 10 is the current distribution of the first antenna during a certain period of time.

[0165] Referring to the embodiment shown in Figure 5A and Figure 10, in one embodiment, one end of the inductive structure 25 is coupled to the first stub 23, and the other end of the inductive structure 25 is coupled to the ground terminal D of the second stub 24. In one embodiment, the inductive structure 25 can be a distributed inductor. In another embodiment, the inductive structure 25 can be a combination of a distributed inductor and a lumped inductor. The coupling connection position between the inductive structure 25 and the first stub 23 is the first position M1. The portion from the open terminal A on the first stub 23 to the first position, together with the inductive structure 25, constitutes the radiator of the first antenna. The sum of the electrical length from the open terminal A of the first stub 23 to the first position M1 and the electrical length of the inductive structure 25 satisfies one-quarter of the wavelength corresponding to the resonant frequency of the first resonance of the first antenna.

[0166] In the embodiment shown in Figure 10, the current of the first resonance of the first antenna excited by the first feed structure 211 flows through the inductive structure 25 in the region where the second branch 24 is located. The second branch 24 does not participate in the radiation of the first antenna, but is used to participate in the second resonance of the second antenna. The inductive structure 25 and the second branch 24 are coupled together, which is beneficial to the weak coupling between the inductive structure 25 and the second branch 24, and is beneficial to improving the radiation performance of the second antenna.

[0167] Figure 11 is a schematic diagram of an antenna provided in one embodiment of this application. The direction indicated by the arrowed indicator line in Figure 11 is the current distribution of the second antenna at a certain time period.

[0168] Referring to the embodiment shown in Figure 5B and Figure 11, in one embodiment, the capacitive structure 26 is a distributed capacitor, formed at a first coupling terminal B and a second coupling terminal C. The capacitive structure 26 is constructed by configuring the structures of the first coupling terminal B and the second coupling terminal C. The required equivalent capacitance value of the capacitive structure 26 can be obtained by setting factors such as the area of ​​the end faces of the first coupling terminal B and the second coupling terminal C, the distance between the first coupling terminal B and the second coupling terminal C, and the corresponding materials of the structures of the first coupling terminal B and the second coupling terminal C. The required equivalent capacitance value of the capacitive structure 26 is used to satisfy the second antenna generating a second resonance.

[0169] Figure 12 is a schematic diagram of an antenna provided according to one embodiment of this application. Referring to Figure 12 and the embodiments shown in Figures 5A and 5B, in one embodiment, the second branch 24 has a first feed point E, and the first branch 23 has a second feed point A (located at the open-circuit end A). The first feed structure 211 is coupled to the first feed point E and is used to feed in a signal of the first frequency band. The second feed structure 212 is coupled to the second feed point A and is used to feed in a signal of the second frequency band. The first resonance corresponds to the signal of the first frequency band, and the second resonance corresponds to the signal of the second frequency band.

[0170] In one embodiment, the second feed point A is located at the open end of the first stub 23. The first feed point E is located between the ground end D and the second coupling end C of the second stub 24. The first feed structure 211 is coupled to the radio frequency chip in the terminal device. The first feed structure 211 transmits the feed signal to the first feed point, exciting the antenna to generate the current of the first antenna. The current of the first antenna in the antenna shown in FIG. 12 can be the same as the current distribution of the first antenna shown in FIG. 5A. The second feed structure 212 is coupled to the radio frequency chip in the terminal device. The second feed structure 212 transmits the feed signal to the second feed point A, exciting the antenna to generate the current of the second antenna. The current of the second antenna in the antenna shown in FIG. 12 can be the same as the current distribution of the second antenna shown in FIG. 5B.

[0171] Figure 13 is a schematic diagram of an antenna provided in one embodiment of this application. Referring to Figure 13 and the embodiments shown in Figures 5A and 5B, the antenna includes a main feed structure 213, a first branch 23 having a main feed point P, and the main feed structure 213 and the main feed point P being coupled together for feeding a first frequency band signal and a second frequency band signal to the main feed point P. The first resonance corresponds to the first frequency band signal, and the second resonance corresponds to the second frequency band signal. In one embodiment, the main feed point P is located at the open end A of the first branch 23.

[0172] Figure 14 is a schematic diagram of an antenna provided according to one embodiment of this application. Referring to Figure 14 and the embodiments shown in Figures 5A and 5B, the antenna includes a main feed structure 213, and a second branch 24 having a main feed point P. The main feed structure 213 and the main feed point P are coupled together for feeding a first frequency band signal and a second frequency band signal to the main feed point P. The first resonance corresponds to the first frequency band signal, and the second resonance corresponds to the second frequency band signal. In one embodiment, the main feed point P is located between the ground terminal D and the second coupling terminal C of the second branch 24.

[0173] Figure 15 is a schematic diagram of an antenna provided in one embodiment of this application. Referring to the embodiments shown in Figures 5A and 5B, and referring to Figure 15, the antenna further includes a switch SW0. The switch SW0 is coupled between the open terminal A of the first branch 23 and the ground plane. The switch SW0 is used to achieve tuning between the parallel capacitor and the parallel inductor at the open terminal A of the first branch 23 to achieve the tuning frequency. When the switch SW0 is used to achieve the state of the parallel capacitor, it is used to achieve tuning that shifts the resonance to a lower value. When the switch SW0 is used to achieve the state of the parallel inductor, it is used to achieve tuning that shifts the resonance to a higher value.

[0174] Figure 16 is a schematic diagram of an antenna provided in one embodiment of this application. Referring to Figure 14 and then to Figure 16, the antenna further includes a switch SW0. The switch SW0 is coupled between the open terminal A of the first branch 23 and the ground plane. The switch SW0 is used to achieve tuning between the parallel capacitor and the parallel inductor at the open terminal A of the first branch 23 to achieve a tuning frequency. When the switch SW0 is used to achieve the state of the parallel capacitor, it is used to achieve tuning that shifts the resonance to a lower value. When the switch SW0 is used to achieve the state of the parallel inductor, it is used to achieve tuning that shifts the resonance to a higher value.

[0175] Figure 17 is a schematic diagram of an antenna provided in one embodiment of this application. Referring to Figure 17 in conjunction with Figure 15, in one embodiment, the capacitive structure 26 is a distributed capacitor, and the capacitive structure 26 is formed at a first coupling end B and a second coupling end C. The capacitive structure 26 is constituted by setting the structure of the first coupling end B and the second coupling end C. The required equivalent capacitance value of the capacitive structure 26 can be obtained by setting factors such as the size of the end face area of ​​the first coupling end B and the second coupling end C, the distance between the first coupling end B and the second coupling end C, and the corresponding materials of the structures of the first coupling end B and the second coupling end C. The required equivalent capacitance value of the capacitive structure 26 is used to satisfy the second antenna generating a second resonance. In one embodiment, the inductive structure 25 is a distributed inductor, and the two ends of the inductive structure 25 are respectively coupled to a first stub and a second stub 24.

[0176] Figures 18A and 18B are schematic diagrams of an antenna provided in one embodiment of this application. Figure 18A shows the current distribution of the first antenna, and the direction indicated by the arrow in Figure 18A is the current distribution of the first antenna during a certain period. Figure 18B shows the current distribution of the second antenna, and the direction indicated by the arrow in Figure 18B is the current distribution of the second antenna during a certain period. Referring to the embodiments shown in Figures 5A and 5B, and referring to Figures 18A and 18B, the antenna 20 further includes a parasitic stub 27, with the open-circuit terminals A of the parasitic stub 27 and the first stub 23 spaced apart. In one embodiment, the first stub 23 is arranged between the second stub 24 and the parasitic stub 27, with the end of the parasitic stub 27 away from the first stub 23 being the parasitic ground terminal H, and the end of the parasitic stub 27 adjacent to the first stub 23 being the parasitic coupling terminal G. The current on the first branch 23 is coupled to the parasitic branch 27 through the gap between the parasitic coupling terminal G and the open terminal A of the first branch 23.

[0177] In one embodiment, the parasitic stub 27 participates in the resonance of the second antenna, which can improve the radiation performance of the second antenna and realize two resonance modes of the second antenna. In another embodiment, the parasitic stub 27 can also be coupled to the first antenna and participate in the resonance of the first antenna, which can realize two resonance modes of the first antenna.

[0178] Referring to Figure 18A, the current distribution of the first antenna is as follows: it flows from the grounding terminal D of the second branch 24 to the location where the inductive structure 25 and the second branch 24 are coupled, flows along the inductive structure 25 to the first branch 23, and flows from the location where the first branch 23 and the inductive structure 25 are coupled to the open terminal A of the first branch 23.

[0179] Referring to Figure 18B, the solid line with arrows represents the current distribution of the second antenna in the resonant mode of the first frequency band, and the dashed line with arrows represents the current distribution of the second antenna in the resonant mode of the second frequency band. In one embodiment, the parasitic stub 27 is used to operate within the frequency range of the second resonance generated by the second antenna. In one embodiment, the second antenna includes a first frequency band and a second frequency band. The second antenna generates two resonant modes, one of which has a frequency range in the first frequency band, and the other has a frequency range in the second frequency band. In the first resonant mode, the second antenna is excited, and the direction of the current in the first stub 23 and the second stub 24 is the same as the direction of the current in the excited parasitic stub 27. In the second resonant mode, the direction of the current in most or all areas of the first stub 23 and the second stub 24 excited by the second antenna is opposite to the direction of the current in the excited parasitic stub 27.

[0180] Figures 19A and 19B are schematic diagrams of an antenna provided in one embodiment of this application. Figure 19A shows the current distribution of the first antenna, and the direction indicated by the arrow in Figure 19A is the current distribution of the first antenna at a certain time period. Figure 19B shows the current distribution of the second antenna, and the direction indicated by the arrow in Figure 19B is the current distribution of the second antenna at a certain time period. Referring to Figures 18A and 18B, and referring to Figures 19A and 19B, in one embodiment, the electrical length L of the parasitic stub 27 is one-quarter of the wavelength corresponding to the resonant frequency of the first resonance. The parasitic stub 27 is used to operate within the frequency range of the first resonance, and the parasitic stub 27 participates in the radiation of the first antenna.

[0181] The first stub 23, inductive structure 25, second stub 24, and parasitic stub 27 can construct two resonant modes of the first antenna. The first antenna includes a first frequency band and a second frequency band. The frequency range of the first resonant mode is the first frequency band, and the frequency range of the second resonant mode is the second frequency band. Referring to Figure 19A, the solid line with arrows represents the current distribution of the first antenna in the resonant mode in the first frequency band, and the dashed line with arrows represents the current distribution of the first antenna in the resonant mode in the second frequency band. In the first resonant mode, the current distribution of the first antenna is as follows: it flows from the ground terminal D of the second stub 24 to the coupling connection between the inductive structure 25 and the second stub 24, along the inductive structure 25 to the first stub 23, from the coupling connection between the first stub 23 and the inductive structure 25 to the open terminal A of the first stub 23, and finally from the parasitic coupling terminal G of the parasitic stub 27 to the parasitic ground terminal H. In the second resonant mode, the current distribution of the first antenna is as follows: it flows from the ground terminal D of the second stub 24 to the coupling point between the inductive structure 25 and the second stub 24, then along the inductive structure 25 to the first stub 23, and from the coupling point between the first stub 23 and the inductive structure 25 to the open terminal A of the first stub 23. The current flows from the parasitic ground terminal H of the parasitic stub 27 to the parasitic coupling terminal G. The current direction on the parasitic stub 27 is opposite to the current direction distributed on the first stub 23, the second stub 24, and the inductive structure 25.

[0182] Referring to Figure 19B, the current distribution of the second antenna is as follows: from the grounding terminal D of the second branch 24 to the location where the capacitive structure 26 and the second branch 24 are coupled, and from the location where the capacitive structure 26 and the first branch 23 are coupled to the open terminal A of the first branch 23.

[0183] Figure 20 is a schematic diagram of an antenna provided in one embodiment of this application. Referring to Figure 20, in conjunction with the embodiments shown in Figures 19A and 19B, the antenna 20 includes a first switch SW1, which is connected in series between a first stub 23 and a second stub 24. In one embodiment, one end of the first switch SW1 is connected to a first coupling terminal B, and the other end is connected to a second coupling terminal C. The first switch SW1 is used to tune the first resonance of the first antenna and the second resonance of the second antenna. In one embodiment, the antenna 20 further includes a second switch SW2, one end of which is coupled to ground, and the other end is coupled to the open terminal A of the first stub 23 or the parasitic coupling terminal G of the parasitic stub 27. When the second switch SW2 is coupled to the first stub 23 and ground, it is used to tune the resonant mode of the antenna in which the first stub 23 and the second stub 24 participate in radiation; when the second switch SW2 is coupled to the parasitic stub 27 and ground, it is used to tune the resonant mode of the antenna in which the parasitic stub 27 participates in radiation. In one embodiment, the second switch SW2 is located at the position corresponding to the gap between the first stub 23 and the parasitic stub 27. In another embodiment, the second switch SW2 is coupled between the first stub 23 and the parasitic stub 27 to support the tuning of the resonant modes of the antenna radiated by the first stub 23 and the second stub 24, as well as the tuning of the resonant modes of the antenna radiated by the parasitic stub 27.

[0184] In one embodiment shown in Figure 20, one end of the first switch SW1 between the first stub 23 and the second stub 24 is grounded, and the other end is coupled to either the first coupling terminal B of the first stub 23 or the second coupling terminal C of the second stub 24. The first coupling terminal B has at least two switch switching contacts. The second coupling terminal C may also have at least two switch switching contacts. By adjusting the switch to different switch switching contact positions, the first resonance of the first antenna and the second resonance of the second antenna can be tuned. In another embodiment, one end of the second switch SW2 between the first stub 23 and the parasitic stub 27 is coupled to the parasitic stub 27, and the other end is coupled to the first stub 23. At least two switch switching contacts are coupled to the first stub 23. By adjusting the switch to different switch switching contact positions, one resonant frequency band of the second resonance of the second antenna can be tuned.

[0185] In one embodiment shown in Figure 20, a first feed point E is provided on the second branch 24, and the first feed point E is coupled to a first feed structure 211. The first feed structure 211 is used to feed the signal of the first antenna into the first feed point E. A second feed point F is provided on the first branch 23, and the second feed point F is coupled to a second feed structure 212. The second feed structure 212 is used to feed the signal of the second antenna into the second feed point F.

[0186] In one embodiment shown in Figure 20, the inductive structure 25 is a distributed inductor. The inductive structure 25 and the first branch 23 are coupled at a first position M1, and the inductive structure 25 and the second branch 24 are coupled at a second position M2. The first feed point E and the second feed point F are located between the first position M1 and the second position M2.

[0187] Figure 21 is a schematic diagram of an antenna provided according to one embodiment of this application. Referring to the embodiment shown in Figure 20 and to Figure 21, in one embodiment, the first stub 23 has a first feed point E and a second feed point F. The inductive structure 25 is coupled to the first stub 23 at a first position M1, which is located between the first feed point E and the second feed point F. In another embodiment, the second feed point F is located between the first position M1 and the first coupling terminal B, and the first feed point is located between the open terminal A of the first stub 23 and the first position M1.

[0188] Figures 22A and 22B are schematic diagrams of an antenna provided in one embodiment of this application. Figure 22A shows the current distribution of the first antenna, and Figure 22B shows the current distribution of the second antenna. Referring to the embodiment shown in Figure 21, and referring to Figures 22A and 22B, in one embodiment, the antenna 20 may also have only one main feed structure 213 and one main feed point P. The main feed point P may be located on the first stub 23 or on the second stub 24. The main feed structure 213 feeds the main feed point P, enabling simultaneous feeding of signals from the first antenna and the second antenna. Referring to Figure 22A, in one embodiment, the current of the first antenna flows from the ground terminal D of the second stub 24 to the location where the inductive structure 25 and the second stub 24 are coupled, flows along the inductive structure 25 to the location where the inductive structure 25 and the first stub 23 are coupled, and flows along the first stub 23 to the open terminal A of the first stub 23. Referring to Figure 22A, in one embodiment, the second antenna has two resonance modes. In the first resonant mode, the current on the second antenna is in the same direction, flowing from the ground terminal D of the second stub 24 to the second coupling terminal C of the second stub 24, then through the first coupling terminal B of the first stub 23 to the open terminal A of the first stub 23, and then into the parasitic stub 27, flowing to the ground terminal D of the parasitic stub 27. In the second resonant mode, the current on the second antenna is in opposite directions. The first direction of the current flows from the ground terminal D of the second stub 24 to the first stub 23 and into the interior of the first stub 23, while the second direction of the current flows from the ground terminal D of the parasitic stub 27 to the first stub 23 and into the interior of the first stub 23. In one embodiment, two currents in opposite directions can be distributed on the first stub 23.

[0189] Figures 23A and 23B are schematic diagrams of an antenna provided in one embodiment of this application. Figure 23A shows the current distribution of the first antenna, and Figure 23B shows the current distribution of the second antenna. Referring to the embodiment shown in Figure 20 and Figures 23A and 23B, in one embodiment, the electrical length of the parasitic stub 27 is one-quarter of the wavelength corresponding to the resonant frequency of the first resonance. The parasitic stub 27 is used to operate within the frequency range of the first resonance and participates in the radiation of the first antenna. The first antenna has two resonance modes, as shown in Figure 23A, where the solid line with arrows represents the current distribution of the first antenna in the first resonance mode, and the dashed line with arrows represents the current distribution of the first antenna in the second resonance mode. Referring to Figure 23B, the current distribution of the second antenna is as follows: it flows from the ground terminal D of the second stub 24 to the position where the capacitive structure 26 and the second stub 24 are coupled, and through the capacitive structure 26, it flows from the coupling connection position of the capacitive structure 26 and the first stub 23 to the open terminal A of the first stub 23.

[0190] Figure 24 is a schematic diagram showing the system overall efficiency and radiation efficiency curves of the first antenna in the embodiments shown in Figures 23A and 23B. The dashed line RE represents the radiation efficiency of the first antenna, and the solid line SE represents the system overall efficiency of the first antenna. In one embodiment, the antenna provided in the embodiments shown in Figures 23A and 23B has a capacitor and an inductor at both feed points. The equivalent capacitance of the capacitor connected in series at the first feed point is 3pF, the equivalent capacitance of the capacitor connected in parallel at the first feed point is 3pF, and the equivalent inductance of the inductor connected in parallel at the first feed point is 10nH. The equivalent capacitance of the capacitor connected in series at the second feed point is 2pF, and the equivalent inductance of the inductor connected in parallel at the second feed point is 2nH. The equivalent capacitance of the capacitive structure 26 formed by the gap between the first stub 23 and the second stub 24 is 0.5pF. Referring to Figure 24, the first antenna generates two resonant modes, one of which has a frequency band between 650MHz and 720MHz, and the other has a frequency band between 750MHz and 810MHz.

[0191] Figures 25A and 25B are schematic diagrams of an antenna provided in one embodiment of this application. Figure 25A includes the current distribution of the first antenna, and Figure 25B includes the current distribution of the second antenna. Referring to Figures 25A and 25B, the antenna 20 includes a first radiating stub 28, a second radiating stub 29, and a parasitic stub 27. One end of the first radiating stub 28 is a ground terminal D, and the other end of the first radiating stub 28 is a first coupling terminal B. One end of the second radiating stub 29 is a second coupling terminal C, and the other end of the second radiating stub 29 is a third coupling terminal T. One end of the parasitic stub 27 is a parasitic ground terminal H, and the other end of the parasitic stub 27 is a parasitic coupling terminal G. The second radiating stub 29 is located between the parasitic stub 27 and the first radiating stub 28. The second coupling terminal C of the second radiating stub 29 and the first coupling terminal B of the first radiating stub 28 are opposite to each other and spaced apart. The third coupling terminal T of the second radiating stub 29 and the parasitic coupling terminal G of the parasitic stub 27 are opposite to each other and spaced apart.

[0192] Antenna 20 also includes the inductive structure 25, one end of which is coupled to the parasitic stub 27, and the other end to the second radiating stub 29. A portion of the parasitic stub 27, the inductive structure 25, and a portion of the second radiating stub 29 constitute a first antenna for generating a first resonance. The sum of the electrical lengths of the parasitic stub 27 and the second radiating stub 29 is less than one-quarter of the wavelength corresponding to the resonant frequency of the first resonance.

[0193] The antenna also includes a capacitive structure 26 connected in series between the first radiating stub 28 and the second radiating stub 29. The first radiating stub 28, the capacitive structure 26, and the second radiating stub 29 constitute a second antenna. The second antenna is used to generate a second resonance. The sum of the electrical lengths of the first radiating stub 28 and the second radiating stub 29 is greater than one-quarter of the wavelength corresponding to the resonant frequency of the second resonance.

[0194] This application embodiment connects an inductive structure in parallel and a capacitive structure in series between the second radiating stub and the parasitic stub. A first antenna and a second antenna can be constructed through the first radiating stub, the second radiating stub, the parasitic stub, and the inductive and capacitive structures. The first antenna uses an inductive structure, and the second antenna uses a capacitive structure. This application constructs different antenna radiators based on the same radiating stub, realizing antenna reconfiguration. This is beneficial for arranging two or more antennas in a limited space, saving the space occupied by antennas in the terminal device. For the terminal device, it can accommodate more antennas and improve the radio frequency transceiver performance of the terminal device.

[0195] In one embodiment, the inductive structure 25 is a distributed inductor. One end of the inductive structure 25 is coupled to the parasitic stub 27 at a position between the two ends of the parasitic stub 27, and the other end of the inductive structure 25 is coupled to the second radiating stub 29 at a position between the two ends of the second radiating stub 29.

[0196] In one embodiment, the inductive structure 25 is a lumped inductor, one end of the inductive structure 25 is coupled to the third coupling terminal T of the second radiating stub 29, and the other end of the inductive structure 25 is coupled to the parasitic coupling terminal G of the parasitic stub 27.

[0197] In one embodiment, the antenna 20 includes a total feed structure 213, and the second radiating stub 29 has a total feed point P. The total feed structure 213 and the total feed point P are coupled together for feeding a first frequency band signal and a second frequency band signal to the total feed point P. The first resonance corresponds to the first frequency band signal, and the second resonance corresponds to the second frequency band signal.

[0198] The location of the total feed point P is located at one end of the second radiating branch 29 adjacent to the parasitic branch 27.

[0199] In one embodiment, the antenna 20 further includes a first switch SW1, which is coupled between the first radiating stub 28 and the second radiating stub 29. The first switch SW1 is used to tune one of the resonant frequency bands of the second resonance of the second antenna. The first switch SW1 may include multiple switching contacts arranged in parallel. By turning on different switching contacts, the antenna can be tuned.

[0200] In one embodiment, the antenna further includes a second switch SW2 located between the second radiating stub 29 and the parasitic stub 27, and coupled between them. One end of the second switch SW2 is coupled to ground, and the other end is coupled to a third coupling terminal T of the second radiating stub 29 or a parasitic coupling terminal G of the parasitic stub 27. When the second switch SW2 is coupled to the second radiating stub 29 and ground, it is used to tune the resonant mode of the antenna in which the first radiating stub 28 and the second radiating stub 29 participate in radiation. When the second switch SW2 is coupled to the parasitic stub 27 and ground, it is used to tune the resonant mode of the antenna in which the parasitic stub 27 participates in radiation. The second switch SW2 is used to tune the first resonance of the first antenna and to tune another resonant frequency band of the second resonance of the second antenna.

[0201] In one embodiment, the first resonant frequency band of the first antenna includes at least one communication frequency band within the frequency range of 698MHz-960MHz. The second resonant frequency band of the second antenna includes at least one communication frequency band within the frequency range of 1700MHz-2700MHz.

[0202] Figure 26A is a schematic diagram of an antenna provided in one embodiment of this application. Referring to Figure 26A, in conjunction with the embodiments shown in Figures 25A and 25B, the antenna 20 includes a first feed structure 211 and a second feed structure 212. The second radiating stub 29 has a first feed point E and a second feed point F. The first feed structure 211 and the first feed point E are coupled together and used to feed signals in a first frequency band. The second feed structure 212 and the second feed point F are coupled together and used to feed signals in a second frequency band. The first resonance corresponds to the signal in the first frequency band, and the second resonance corresponds to the signal in the second frequency band. In one embodiment, the first feed point E is adjacent to the second coupling end C of the second radiating stub 29, and the second feed point is adjacent to the third coupling end D of the second radiating stub 29. The coupling connection position of the inductive structure 25 and the second radiating stub 29 is a first position M1, which is located between the first feed point E and the second feed point F. This scheme arranges the first feed point E and the second feed point F at the adjacent ends of the second radiating stub 29, which is beneficial for setting the feed matching structure of the first antenna and the second antenna, and also facilitates the tuning of the resonance and bandwidth of the first antenna and the second antenna.

[0203] Figure 26B is a schematic diagram of the S77 curve of the antenna provided in the embodiment shown in Figure 26A. Referring to Figure 26B, it can be seen that the first antenna of the antenna provided in the embodiment shown in Figure 26A has one resonant mode (e.g., 0.749 GHz), and the second antenna has two resonant modes (e.g., 1.912 GHz and 2.264 GHz).

[0204] Figure 26C is a schematic diagram of the system overall efficiency and radiation efficiency curves of the first antenna in the embodiment shown in Figure 26A. Curve SE represents the system overall efficiency of the first antenna, and curve RE represents the radiation efficiency of the first antenna. Referring to Figure 26C, it can be seen that the system overall efficiency and radiation efficiency of the first antenna in the embodiment shown in Figure 26A both meet the requirements of the antenna's radiation performance.

[0205] Figure 26D is a schematic diagram of the overall system efficiency and radiation efficiency curves of the second antenna in the antenna provided by the embodiment shown in Figure 26A. Curve SE represents the overall system efficiency of the second antenna, and curve RE represents the radiation efficiency of the second antenna. Referring to Figure 26D, it can be seen that the overall system efficiency and radiation efficiency of the second antenna in the antenna provided by the embodiment shown in Figure 26A both meet the requirements of the antenna's radiation performance.

[0206] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0207] The above description is merely a specific embodiment 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 technical scope disclosed in this application should be included within the scope of protection of this application. Where there is no conflict, possible embodiments of this application and features thereof can be combined with each other. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An antenna, characterized by It includes a first branch, a second branch, an inductive structure, and a capacitive structure. One end of the first branch is an open circuit, and the other end is a first coupling terminal. One end of the second branch is a second coupling terminal, and the other end is a ground terminal. A gap is formed between the second coupling terminal and the first coupling terminal. One end of the inductive structure is coupled to the first branch, and the other end of the inductive structure is coupled to the second branch. One end of the capacitive structure is coupled to the first branch, and the other end of the capacitive structure is coupled to the second branch; The first stub, the inductive structure, and the second stub constitute a first antenna, which is used to generate a first resonance; The first stub, the capacitive structure, and the second stub constitute a second antenna, which is used to generate a second resonance; The second antenna operates at a higher frequency at the second resonance than the first antenna operates at the first resonance.

2. The antenna according to claim 1, characterized in that, The sum of the electrical lengths of the second stub and the first stub is less than one-quarter of the wavelength corresponding to the resonant frequency of the first resonance; and / or The sum of the electrical length of the second stub and the electrical length of the first stub is greater than one-quarter of the wavelength corresponding to the resonant frequency of the second resonance.

3. The antenna according to claim 1 or 2, characterized in that The sensitivity range of the inductive structure is 3nH-10nH.

4. The antenna according to any one of claims 1-3, characterized in that, The capacitance of the capacitive structure is adjustable, and the capacitive structure is used to tune the resonance generated by the second antenna.

5. The antenna according to any one of claims 1-4, characterized in that, The inductive structure is a lumped inductor or a distributed inductor; or, the capacitive structure is a lumped capacitor or a distributed capacitor.

6. The antenna according to any one of claims 1-5, wherein, The antenna further includes a first feeding structure and a second feeding structure. The second branch has a first feeding point and a second feeding point. Along the extension direction of the second branch, the grounding terminal, the first feeding point, the second feeding point, and the second coupling terminal are arranged in sequence at intervals. The first feeding structure and the first feeding point are coupled together and used to feed in a signal of the first frequency band. The second feeding structure and the second feeding point are coupled together and used to feed in a signal of the second frequency band. The first resonance corresponds to the signal of the first frequency band, and the second resonance corresponds to the signal of the second frequency band.

7. The antenna according to any one of claims 1-5, wherein, The antenna further includes a first feeding structure and a second feeding structure. The second branch has a first feeding point, and the first branch has a second feeding point. The first feeding structure and the first feeding point are coupled together and used to feed in a signal of a first frequency band. The second feeding structure and the second feeding point are coupled together and used to feed in a signal of a second frequency band. The first resonance corresponds to the signal of the first frequency band, and the second resonance corresponds to the signal of the second frequency band.

8. The antenna according to any one of claims 1-5, wherein, The antenna includes a total feed structure, with the first stub or the second stub having a total feed point. The total feed structure and the total feed point are coupled together for feeding a signal of a first frequency band and a signal of a second frequency band to the total feed point. The first resonance corresponds to the signal of the first frequency band, and the second resonance corresponds to the signal of the second frequency band.

9. The antenna according to any of claims 1-8, characterized by The antenna also includes a switch coupled between the open end of the first stub and the ground.

10. The antenna according to any one of claims 1-9, wherein, The first resonant frequency band includes at least one communication frequency band in the frequency range of 698MHz-960MHz; and / or, the second resonant frequency band includes at least one communication frequency band in the frequency range of 1700MHz-2700MHz.

11. The antenna according to any of claims 1-10, characterized by It also includes parasitic branches, which are spaced apart from the open ends of the first branch.

12. The antenna according to claim 11, characterized in that, It also includes a first switch, which is coupled between the first stub and the second stub, and is used to tune the first resonance of the first antenna and the second resonance of the second antenna.

13. The antenna according to claim 12, characterized in that, It also includes a second switch, one end of which is coupled to ground, and the other end is coupled to the open end of the first stub or the parasitic coupling end of the parasitic stub. The parasitic coupling end is the end of the parasitic stub adjacent to the first stub. The second switch is used to tune one of the resonant frequency bands in the second resonance of the second antenna.

14. The antenna according to any of claims 11-13, characterized by The electrical length of the parasitic branch is one-quarter of the wavelength corresponding to the resonant frequency of the first resonance.

15. An antenna, characterized by It includes a first radiating branch, a second radiating branch, and a parasitic branch. One end of the first radiating branch is a grounding terminal, and the other end of the first radiating branch is a first coupling terminal. One end of the second radiating branch is a second coupling terminal, and the other end of the second radiating branch is a third coupling terminal. One end of the parasitic branch is a grounding terminal, and the other end of the parasitic branch is a fourth coupling terminal. The second radiating branch is located between the parasitic branch and the first radiating branch. The second coupling terminal of the second radiating branch and the first coupling terminal of the first radiating branch are opposite to each other and spaced apart. The third coupling terminal of the second radiating branch and the fourth coupling terminal of the parasitic branch are opposite to each other and spaced apart. The antenna further includes the inductive structure, one end of which is coupled to the parasitic stub and the other end of which is coupled to the second radiating stub; a portion of the parasitic stub, the inductive structure, and a portion of the second radiating stub constitute a first antenna, which is used to generate a first resonance; The antenna further includes a capacitive structure coupled between the first radiating stub and the second radiating stub. The first radiating stub, the capacitive structure, and the second radiating stub constitute a second antenna, which is used to generate a second resonance. The second antenna operates at a higher frequency at the second resonance than the first antenna operates at the first resonance.

16. The antenna according to claim 15, characterized in that, The sum of the electrical length of the parasitic branch and the electrical length of the second radiating branch is less than one-quarter of the wavelength corresponding to the resonant frequency of the first resonance. and / or The sum of the electrical lengths of the first radiating stub and the second radiating stub is greater than one-quarter of the wavelength corresponding to the resonant frequency of the second resonance.

17. The antenna according to claim 15 or 16, characterized in that The inductive structure is a distributed inductor. One end of the inductive structure is coupled to the parasitic branch at a position between the two ends of the parasitic branch, and the other end of the inductive structure is coupled to the second radiating branch at a position between the two ends of the second radiating branch. or, The inductive structure is a lumped inductor, one end of which is coupled to the third coupling terminal of the second radiating stub, and the other end of which is coupled to the fourth coupling terminal of the parasitic stub.

18. The antenna according to any of claims 15-17, characterized by The antenna also includes a first switch, which is coupled between the first radiating stub and the second radiating stub. The first switch is used to tune one of the resonant frequency bands of the second resonance of the second antenna.

19. The antenna according to claim 18, wherein, The antenna further includes a second switch coupled between the second radiating stub and the parasitic stub. The second switch is used to tune the first resonance of the first antenna and to tune another resonant frequency band of the second resonance of the second antenna.

20. A terminal device, comprising: It includes a radio frequency chip and an antenna as described in any one of claims 1-19, wherein the radio frequency chip is used to power the antenna.

Images