Antenna structure and electronic equipment

Abstract

The invention provides an antenna structure and electronic equipment. The antenna structure comprises n antenna units, n transmission lines and a signal line, the n antenna units are in one-to-one connection with the n transmission lines, and the n transmission lines are connected with the signal line after being combined at a combining point; wherein the n transmission lines are arranged according to the size sequence of the first phase values, the first phase values are values obtained by complementing 180 degrees by absolute phases of the transmission lines, and the difference value between the first phase value corresponding to the kth transmission line in the n transmission lines and the first phase value corresponding to the (k + 1) th transmission line is 180 degrees / n + / -180 degrees / 2n, the output impedance of the combining point is smaller than the characteristic impedance of the transmission line with the smallest characteristic impedance in the n transmission lines, n is larger than or equal to 2, and k is larger than or equal to 1 and smaller than n. According to the technical scheme, the antenna structure can be arranged in the electronic equipment with limited space, and good matching can be realized, so that the signal transmitting capability is improved.

Description

Technical Field

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

[0002] An electronic device can achieve communication functions through an antenna. Generally, the signal transmission ability of an antenna highly depends on the matching degree of the antenna. The better the antenna matching, the less signal reflection and the more signal transmission. Antenna matching is a process to ensure maximum power transfer between the antenna and the transmission line or RF circuit in an RF system. The goal of antenna matching is to match the input impedance of the antenna with the output impedance of the system to minimize reflection loss and ensure that as much RF energy as possible is transmitted into the antenna.

[0003] With the increasing demand for high-speed data transmission, the industrial design (ID) of electronic devices is developing towards a trend of large screen ratio and multiple cameras, which also causes a significant reduction in the antenna clearance and increasingly limited layout space. Currently, a distributed antenna design is mostly adopted, where multiple radiators connected to the same signal source are set in the electronic device to transmit RF signals. In this way, there are more degrees of freedom to design the antenna to adapt to the layout space of the electronic device. However, the matching effect of the existing distributed antenna is not good, resulting in low signal transmission ability of the antenna.

[0004] Therefore, in the increasingly tense layout space of electronic devices, how to design an antenna with a better matching degree is an urgent problem to be solved. Summary of the Invention

[0005] This application provides an antenna structure and an electronic device, which can have good matching, thereby improving the signal transmission ability.

[0006] In a first aspect, an antenna structure is provided, including: n antenna units, n transmission lines, and a signal line. The n antenna units are connected to the n transmission lines one by one. After being combined at a combining point, the n transmission lines are connected to the signal line. Wherein, the n transmission lines are arranged in the order of the magnitude of the first phase value, and the first phase value is the remainder of the absolute phase of the transmission line divided by 180°. The difference between the first phase value corresponding to the k-th transmission line among the n transmission lines and the first phase value corresponding to the (k + 1)-th transmission line among the n transmission lines is 180° / n ± 180° / 2n. The output impedance of the combining point is less than the characteristic impedance of the transmission line with the smallest characteristic impedance among the n transmission lines. n is greater than or equal to 2, and k is greater than or equal to 1 and less than n.

[0007] In the embodiments of the present application, after passing through a transmission line with a phase difference of 180 / n ± 180° / 2n, the antenna unit can be transformed into an impedance value different from the antenna impedance of the antenna unit itself, showing a phenomenon with both inductance and capacitance. When n antenna units are connected in parallel, the inductance and capacitance of different antenna units can cancel each other out, thereby forming an input impedance with relatively small inductance and capacitance at the combining point. This is beneficial for obtaining good impedance matching and further improving the signal transmission ability.

[0008] In combination with the first aspect, in some implementation manners of the first aspect, the n transmission lines are directly connected to the signal line after being combined at the combining point.

[0009] In this way, the antenna architecture is simple and convenient to be arranged in an electronic device with limited space.

[0010] In combination with the first aspect, in some implementation manners of the first aspect, the antenna structure further includes: a matching network, and the matching network is arranged between the combining point and the signal line.

[0011] By adding a matching network before connecting the signal line, the matching can be further optimized.

[0012] In combination with the first aspect, in some implementation manners of the first aspect, the output impedance of the combining point is the characteristic impedance of the signal line.

[0013] In this way, it is beneficial to naturally obtain impedance matching.

[0014] In combination with the first aspect, in some implementation manners of the first aspect, the characteristic impedance of the signal line is less than the characteristic impedance of the transmission line with the smallest characteristic impedance among the n transmission lines.

[0015] In combination with the first aspect, in some implementation manners of the first aspect, the antenna structure further includes: an impedance transformer, and the impedance transformer is arranged between the combining point and the signal line.

[0016] The impedance transformer can perform impedance transformation between the combining point and the signal line, and can decouple the characteristic impedance of the signal line from the characteristic impedance of the transmission line.

[0017] In combination with the first aspect, in some implementation manners of the first aspect, the output impedance of the combining point is the impedance obtained by transforming the characteristic impedance of the signal line through the impedance transformer.

[0018] In combination with the first aspect, in some implementation manners of the first aspect, the output impedance of the combining point is less than the characteristic impedance of the signal line.

[0019] In combination with the first aspect, in some implementation manners of the first aspect, the characteristic impedance of the signal line is greater than or equal to the characteristic impedance of the transmission line with the smallest characteristic impedance among the n transmission lines.

[0020] In combination with the first aspect, in some implementations of the first aspect, the characteristic impedance value of each of the n transmission lines is a first value, the characteristic impedance of the signal line is a third value, and the third value is equal to the first value.

[0021] The characteristic impedance of the signal line is the same as that of the transmission line.

[0022] In combination with the first aspect, in some implementations of the first aspect, the impedance transformer is a quarter-wavelength impedance transformer.

[0023] In combination with the first aspect, in some implementations of the first aspect, the characteristic impedance of each of the n transmission lines is a first value, the output impedance of the combining point is a second value, and the second value is 1 / n of the first value.

[0024] In combination with the first aspect, in some implementations of the first aspect, the first antenna unit among the n antenna units is any one of the following antenna forms: wire antenna, patch antenna, or slot antenna.

[0025] In combination with the first aspect, in some implementations of the first aspect, when the first antenna unit is a wire antenna, the radiator of the first antenna unit is L-shaped.

[0026] In combination with the first aspect, in some implementations of the first aspect, when the first antenna unit is a patch antenna, the first antenna unit includes a first patch and a second patch arranged side by side. The first patch includes a first open end and a first ground end, and the second patch includes a second open end and a second ground end. Among them, the second ground end is rotated 90° relative to the first ground end, the second open end is rotated 90° relative to the first open end, and the rotation directions of the second open end and the second ground end are the same.

[0027] The first antenna unit includes two patches, which can form double resonance, thereby expanding the operating bandwidth of the antenna.

[0028] In combination with the first aspect, in some implementations of the first aspect, when the first antenna unit and the second antenna unit among the n antenna units are patch antennas, the first antenna unit includes a third patch, the second antenna unit includes a fourth patch, the third patch is excited with a first resonance mode, and the fourth patch is excited with a second resonance mode.

[0029] Different antenna units are excited with different resonance modes, which can form double resonance or multi-resonance, thereby expanding the operating bandwidth of the antenna.

[0030] In combination with the first aspect, in some implementations of the first aspect, the antenna forms of the n antenna units are the same.

[0031] In combination with the first aspect, in some implementations of the first aspect, the absolute phases of the n transmission lines form an arithmetic progression.

[0032] In combination with the first aspect, in some implementations of the first aspect, the combining point is located on the radiator of the third antenna element among the n antenna elements.

[0033] In combination with the first aspect, in some implementations of the first aspect, the physical length of the transmission line connected to the third antenna element is zero, the absolute phase of the transmission line connected to the third antenna element is zero, and the characteristic impedance of the transmission line connected to the third antenna element is equal to the characteristic impedance of the transmission line connected to the fourth antenna element among the n antenna elements, where the fourth antenna element is any one of the n antenna elements other than the third antenna element.

[0034] In combination with the first aspect, in some implementations of the first aspect, the difference between the first phase value corresponding to the k-th transmission line and the first phase value corresponding to the (k + 1)-th transmission line is achieved by at least one of the following methods: generating a phase difference by adjusting the length difference between the k-th transmission line and the (k + 1)-th transmission line; generating a phase difference by a phase shifter; generating a phase difference by a capacitor and / or an inductor; generating a phase difference by a coupled line; or generating a phase difference by adjusting the antenna forms of the antenna elements respectively connected to the k-th transmission line and the (k + 1)-th transmission line.

[0035] In combination with the first aspect, in some implementations of the first aspect, the antenna structure is a distributed antenna.

[0036] Based on the distributed antenna design, there are more degrees of freedom to design the antenna, thus obtaining better matching results.

[0037] In a second aspect, an electronic device is provided, including the antenna structure in the first aspect and any implementation of the first aspect.

[0038] In combination with the second aspect, in some implementations of the second aspect, the electronic device further includes a radio frequency chip, which is used to adjust the radio frequency signals received and transmitted by the antenna structure.

[0039] For the beneficial effects of the electronic device related to the second aspect above, reference can be made to the relevant descriptions of the first aspect. For the sake of brevity, they will not be elaborated here. Description of the Drawings

[0040] Figure 1 It is a schematic structural diagram of an electronic device provided by an embodiment of the present application.

[0041] Figure 2It is a schematic structural diagram of an antenna structure provided by an embodiment of the present application.

[0042] Figure 3 It is a schematic structural diagram of an antenna structure provided by an embodiment of the present application.

[0043] Figure 4 It is a schematic structural diagram of an antenna structure provided by an embodiment of the present application.

[0044] Figure 5 Figure 4 Two possible circuit connection schematic diagrams of the antenna structure in

[0045] Figure 6 It is Figure 4 The antenna structure in Figure 5 The polar coordinate diagram of the reflection coefficient connected according to Circuit 1 in

[0046] Figure 7 It is Figure 4 The antenna structure in Figure 5 The S-parameter simulation result connected according to Circuit 1 in

[0047] Figure 8 It is Figure 4 The antenna structure in Figure 5 The matching result schematic diagram connected according to Circuit 2 in

[0048] Figure 9 It is Figure 4 The antenna structure in Figure 5 The S-parameter simulation result connected according to Circuit 2 in

[0049] Figure 10 It is Figure 4 The S-parameter simulation result of the antenna structure in

[0050] Figure 11 It is Figure 4 The S-parameter simulation result of the antenna structure in

[0051] Figure 12 It is Figure 4 The S-parameter simulation result of the antenna structure in

[0052] Figure 13 It is a schematic structural diagram of an antenna structure provided by an embodiment of the present application.

[0053] Figure 14 It is Figure 13 The matching result schematic diagram of the single antenna in

[0054] Figure 15 It is Figure 13 ​Schematic diagram of the matching result of the synthetic antenna with no matching network in

[0055] Figure 16 is Figure 13 Schematic diagram of the matching result of the synthetic antenna with a matching network in

[0056] Figure 17 Schematic diagram of an antenna structure provided by an embodiment of the present application.

[0057] Figure 18 Schematic diagram of an antenna structure provided by an embodiment of the present application.

[0058] Figure 19 is Figure 18 Schematic diagram of the matching result of the antenna structure in

[0059] Figure 20 is Figure 18 Schematic diagram of the matching result of the individual antenna corresponding to the antenna structure in

[0060] Figure 21 Schematic diagram of an antenna structure provided by an embodiment of the present application.

[0061] Figure 22 is Figure 21 Smith chart of the antenna structure in

[0062] Figure 23 is Figure 21 Schematic diagram of the matching result of the individual antenna corresponding to the antenna structure in

[0063] Figure 24 Schematic diagram of an antenna structure provided by an embodiment of the present application.

[0064] Figure 25 is Figure 24 Schematic diagram of the matching result of the antenna structure in

[0065] Figure 26 Schematic diagram of an antenna structure provided by an embodiment of the present application and the corresponding circuit connection diagram.

[0066] Figure 27 is Figure 26 Smith chart of the antenna structure in

[0067] Figure 28 is Figure 26 S-parameter simulation result of the antenna structure in

[0068] Figure 29 Comparison diagram of the matching results between the antenna structure provided by an embodiment of the present application and the existing structure.

[0069] Figure 30It is a schematic structural block diagram of an electronic device provided by an embodiment of the present application. Detailed implementation manners

[0070] The technical solutions in the present application will be described below with reference to the accompanying drawings.

[0071] It should be noted that in the description of the embodiments of the present application, unless otherwise specified, " / " means "or". For example, A / B may mean A or B; herein, "and / or" is merely a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B may mean: A exists alone, A and B exist simultaneously, and B exists alone.

[0072] In the present application, the phrase "within... range", unless it is separately specified that the end values are not included, by default includes the two end values of the range. For example, within the range of 1 to 5, the two values 1 and 5 are included.

[0073] In the embodiments of the present application, the terms "first", "second", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In addition, in the description of the embodiments of the present application, "a plurality of" means two or more than two, "at least one" and "one or more" mean one, two or more than two. The singular forms "a", "one kind", "the", "above-mentioned", "this" and "this one" are also intended to include expressions such as "one or more", unless there is a clear contrary indication in the context.

[0074] The reference to "an embodiment" or "some embodiments" etc. described in this specification means that a specific feature, structure or characteristic described in combination with the embodiment is included in one or more embodiments of the present application. Thus, the statements "in an embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments" etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "include", "comprise", "have" and their variants all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0075] In the description of the embodiments of the present application, the orientation or positional relationship indicated by terms such as "upper", "lower", "inner", "outer", "vertical", "horizontal", etc. is defined relative to the orientation or position in which the components in the drawings are schematically placed. It should be understood that these directional terms are relative concepts, which are used for description and clarification relative to, rather than indicating or implying that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. It can change accordingly with the change of the orientation in which the components in the drawings are placed, so it should not be understood as a limitation to the present application. In addition, the "vertical" involved in the present application is not strictly vertical, but within the allowable error range. The "parallel" is not strictly parallel, but within the allowable error range.

[0076] In the embodiments of the present application, the same reference numeral is used to represent the same component or the same part. For the same parts in the embodiments of the present application, only one of the parts or components may be marked with a reference numeral in the drawing. It should be understood that the reference numeral also applies to other identical parts or components. In addition, the components in the drawings are not drawn to actual scale, and the sizes and dimensions of the components shown in the drawing are only exemplary and should not be understood as a limitation to the present application.

[0077] For ease of understanding, the technical terms involved in the present application will be explained and described below.

[0078] Coupling: includes direct coupling and / or indirect coupling. "Coupled connection" includes direct coupled connection and / or indirect coupled connection. Direct coupling can be understood as physical contact and electrical conduction between components, or as a form of connection between different components in a circuit structure through physical lines such as copper foils or wires of a printed circuit board (PCB) that can transmit electrical signals. Indirect coupling can be understood as electrical conduction between two conductors in a non-contact manner through air space. For example, there is no conductor medium interference between component A and component B, and the energy radiated by component A can be transmitted to component B through the space between component A and component B. In one embodiment, indirect coupling can also be called capacitive coupling. For example, signal transmission is achieved by forming an equivalent capacitance through the coupling between the gaps between two conductive members.

[0079] Element / device: includes at least one of lumped element / devices and distributed element / devices.

[0080] Lumped element: refers to the general term for all elements when the size of the element is much smaller than the wavelength corresponding to the operating frequency of the circuit. For a signal, at any moment, the characteristics of the element always remain fixed and are independent of frequency.

[0081] Distributed element: Different from lumped elements, when the size of an element is about the same as or larger than the wavelength corresponding to the operating frequency of the circuit, the characteristics of each point of the element itself will vary with the change of the signal when the signal passes through the element. At this time, the element as a whole cannot be regarded as a single entity with fixed characteristics, but should be called a distributed element.

[0082] Capacitor: Includes lumped capacitance and / or distributed capacitance. Lumped capacitance refers to capacitive components, such as capacitor elements; distributed capacitance (or distributed capacitor) refers to the equivalent capacitance formed by two conductive parts separated by a certain gap.

[0083] Inductor: Includes lumped inductance and / or distributed inductance. Lumped inductance refers to inductive components, such as inductor elements; distributed inductance (or distributed inductor) refers to the equivalent inductance formed by a conductive part of a certain length.

[0084] Radiator: It is a device in an antenna used to receive / transmit electromagnetic wave radiation. In some cases, "antenna" is understood narrowly as a radiator. The radiator can convert the guided wave energy from the transmitter into radio waves, or convert radio waves into guided wave energy, so as to realize the radiation and reception of radio waves. The modulated high-frequency current energy (or guided wave energy) generated by the transmitter is transmitted to the transmitting radiator through the feeder line. Through the radiator, it is converted into electromagnetic wave energy of a certain polarization and radiated in the required direction. The receiving radiator converts the electromagnetic wave energy of a certain polarization from a specific direction in space back into modulated high-frequency current energy, and transmits it to the input end of the receiver through the feeder line.

[0085] The radiator can include conductors with specific shapes and sizes, such as linear or sheet-like, etc. The present application does not limit the specific shape.

[0086] In one embodiment, the linear radiator may be simply referred to as a wire antenna. In one embodiment, the linear radiator may be implemented by a conductive frame, and may also be referred to as a frame antenna. In one embodiment, the linear radiator may be implemented by a support conductor, and may also be referred to as a support antenna. In one embodiment, the wire 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 dielectric wavelength) (e.g., less than 1 / 16 of the wavelength), and the length may be comparable to the wavelength (e.g., the dielectric wavelength) (e.g., the length is around 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 (IFA), and planar inverted F antennas (PIFA). For example, for a dipole antenna, each dipole antenna generally includes two radiating branches, and each branch is fed by a feeding portion from the feeding end of the radiating branch. For example, an inverted F antenna can be regarded as obtained by adding a grounding path to a monopole antenna. The IFA antenna has a feeding point and a grounding point, and is called an inverted F antenna because its side view is in the shape of an inverted F.

[0087] In one embodiment, the sheet radiator may include a microstrip antenna or a patch antenna. In one embodiment, the sheet radiator may be implemented by a planar conductor (such as a conductive sheet or a conductive coating, etc.). In one embodiment, the sheet radiator may include a conductive sheet, such as a copper sheet. In one embodiment, the sheet radiator may include a conductive coating, such as silver paste. The shapes of the sheet radiator include circular, rectangular, annular, etc., and the present application does not limit the specific shape. The structure of a microstrip antenna generally consists of a dielectric substrate, a radiator, and a ground plane, where the dielectric substrate is disposed between the radiator and the ground plane.

[0088] The radiator may also include slots or slits formed on a conductor. For example, closed or semi-closed slots or slits are formed on a grounded conductor surface. In one embodiment, the slotted or slit radiator may be simply referred to as a slot antenna or a slit antenna. In one embodiment, the radiator with a closed slot or slit may be simply referred to as a closed slot antenna. In one embodiment, the radiator with a semi-closed slot or slit (such as adding an opening to a closed slot or slit) may be simply referred to as an open slot antenna. In some embodiments, the shape of the slit is elongated. In some embodiments, the length of the slit is about half a wavelength (e.g., the dielectric wavelength). In some embodiments, the length of the slit is about an integer multiple of the wavelength (e.g., one dielectric wavelength). In some embodiments, the slit can be fed by a transmission line bridging one or both of its sides. Thus, a radio frequency electromagnetic field is excited on the slit and radiates electromagnetic waves into space. In one embodiment, the radiator of the slot antenna or the slit antenna can be implemented by a conductive frame grounded at both ends, which can also be called a frame antenna; in this embodiment, it can be considered that the slot antenna or the slit antenna includes a linear radiator, which is spaced from the floor and grounded at both ends of the radiator, thereby forming a closed or semi-closed slot or slit. In one embodiment, the radiator of the slot antenna or the slit antenna can be implemented by a support conductor grounded at both ends, which can also be called a support antenna.

[0089] Feeding circuit: It is a combination of all circuits for receiving and transmitting radio frequency signals. The feeding circuit may include a transceiver and a radio frequency front end circuit. In some cases, "feeding circuit" is narrowly understood as a radio frequency integrated circuit (RFIC), and the RFIC can be considered to include a radio frequency front end chip and a transceiver. The feeding circuit has the function of converting radio waves (e.g., radio frequency signals) and electrical signals (e.g., digital signals). Generally, it is considered to be part of the radio frequency.

[0090] In some embodiments, the electronic device may further include a test socket (or called a radio frequency socket or a radio frequency test socket). This test socket can be used to insert a coaxial cable to test the characteristics of the radio frequency front end circuit or the radiator of the antenna through the cable. The radio frequency front end circuit can be considered as the circuit part coupled between the test socket and the transceiver.

[0091] In some embodiments, the radio frequency front end circuit can be integrated into a radio frequency front end chip in the electronic device, or the radio frequency front end circuit and the transceiver can be integrated into a radio frequency chip in the electronic device.

[0092] It should be understood that any two of the first / second / ... / Nth feeding circuits in the present application can share the same transceiver. For example, signals can be transmitted 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, signals can be processed by a switch or an amplifier in a radio frequency front-end.

[0093] It should also be understood that two of the first / second / ... / Nth feeding circuits in the present application generally correspond to two radio frequency test sockets in an electronic device.

[0094] Matching circuit: A circuit used to adjust the radiation characteristics of an antenna. In one embodiment, the matching circuit is coupled between the feeding circuit and the corresponding radiator. In one embodiment, the matching circuit is coupled between the test socket and the radiator. Generally, the matching circuit is a combination of circuits coupled between the radiator and the ground plane. In one embodiment, the matching circuit can include switches and / or electronic components. The switch can be an electronic component for switching the coupling connection of the radiator. The matching circuit has the functions of impedance matching and / or frequency tuning. Generally, it is considered to be part of the antenna.

[0095] When designing an antenna, the maximum power transfer possibility and efficiency should be considered. For this purpose, the antenna feed impedance must match the load resistance. The antenna feed impedance is a combination of resistance, capacitance, and inductance. To ensure the maximum power transfer condition, the two impedances (load resistance and feed impedance) should match. The matching can be achieved by considering the frequency requirements and the design parameters of the antenna (such as gain, directivity, and radiation efficiency). Ideally, when the antenna and the circuit are completely matched, all the current in the circuit is sent to the antenna part, and no current is reflected back at the connection. In actual situations, when the current reflected back to the circuit is small enough to meet the requirements, the antenna can be considered to be matched with the circuit. The quality of the matching can be measured by the following four parameters, namely, reflection coefficient, traveling wave coefficient, voltage standing wave ratio, and return loss. There are fixed numerical relationships among the four parameters.

[0096] Grounding structure / feeding structure: The grounding structure / feeding structure can include connectors, such as metal shrapnel. The radiator is coupled to the ground plane through the grounding structure or coupled to the feeding circuit through the feeding structure. In some embodiments, the feeding structure can include a transmission line / feed line, and the grounding structure can include a ground wire.

[0097] Terminal / Point: The "terminal / point" in the first terminal / second terminal / feeding terminal / grounding terminal / feeding point / grounding point / connection point of the antenna radiator should not be narrowly understood as necessarily being an end point or end part physically disconnected from other radiators. It can also be considered as a certain point or a certain section on a continuous radiator. In one embodiment, the "terminal / point" may include a connection / coupling area on the antenna radiator for coupling and connecting other conductive structures. For example, the feeding terminal / feeding point may be a coupling area on the antenna radiator for coupling and connecting the feeding structure (e.g., an area facing a part of the feeding structure), and for another example, the grounding terminal / grounding point may be a connection / coupling area on the antenna radiator for coupling and connecting the grounding structure.

[0098] Open End, Closed End: In some embodiments, the open end / grounding end, for example, is relative to whether it is grounded. The closed end is grounded and the open end is not grounded. In some embodiments, the open end / closed end, for example, is relative to other conductive bodies. The closed end is electrically connected to other conductive bodies and the open end is not electrically connected to other conductive bodies. In one embodiment, the open end can also be called a floating end, a free end, an open end, or an open-circuit end. In one embodiment, the closed end can also be called a grounding end or a short-circuit end. It should be understood that in some embodiments, other conductive bodies can be coupled and connected through the open end to transfer coupled energy (which can be understood as transferring current).

[0099] Resonance / Resonant Frequency: The resonant frequency is also called the resonance frequency. The resonant frequency can refer to the frequency at which the imaginary part of the antenna input impedance is zero. The resonant frequency can have a frequency range, that is, the frequency range where resonance occurs. The frequency corresponding to the strongest resonance point is the center frequency point.

[0100] Resonant Band / Communication Band / Operating Band: No matter what type of antenna, it always operates within a certain frequency range (bandwidth). For example, an antenna supporting Band B40 has an operating band including frequencies in the range of 2300 MHz to 2400 MHz, or it can be said that the operating band of this antenna includes Band B40. The frequency range that meets the index requirements can be regarded as the operating band of the antenna.

[0101] Electrical Length: It can refer to the ratio of the physical length (i.e., the mechanical length or geometric length) to the wavelength of the transmitted electromagnetic wave. For example, an electrical length of several wavelengths. The electrical length can be calculated using the following formula:

[0102]

[0103] where L is the physical length and λ is the wavelength of the electromagnetic wave.

[0104] Wavelength: Or the operating wavelength, which 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 frequency band (resonant frequency from 1920 MHz to 1980 MHz) is 1955 MHz, the operating wavelength can be the wavelength calculated using this frequency of 1955 MHz. Not limited to the center frequency, the "operating wavelength" can also refer to the wavelength corresponding to a non - center frequency of the resonant frequency or the operating frequency band.

[0105] It should be understood that the wavelength of the radiation signal in air can be calculated as follows: (air wavelength, or vacuum wavelength) = speed of light / frequency, where the frequency is the frequency of the radiation signal (MHz), and the speed of light can be taken as 3×10 8 m / s. The wavelength of the radiation signal in a medium can be calculated as follows: where ε is the relative dielectric constant of the medium. The wavelength in the embodiments of the present application generally refers to the medium wavelength, which can be the medium 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 frequency band (resonant frequency from 1920 MHz to 1980 MHz) is 1955 MHz, the wavelength can be the medium wavelength calculated using this frequency of 1955 MHz. Not limited to the center frequency, the "medium wavelength" can also refer to the medium wavelength corresponding to a non - center frequency of the resonant frequency or the operating frequency band. For ease of understanding, the medium wavelength mentioned in the embodiments of the present application can be simply calculated through the relative dielectric constant of the medium filled on one side or multiple sides of the radiator.

[0106] Antenna return loss (return loss, RL): It can be understood as the ratio of the signal power reflected back to the antenna port through the antenna circuit to the transmission power of the antenna port. The smaller the reflected signal, the larger the signal radiated into space through the antenna, and the higher the radiation efficiency of the antenna. The larger the reflected signal, the smaller the signal radiated into space through the antenna, and the lower the radiation efficiency of the antenna.

[0107] The antenna return loss can be represented by the S11 parameter. S11 belongs to one of the scattering (scatter) parameters (also known as S - parameters). S11 represents the reflection coefficient, and this parameter can characterize the quality of the antenna transmission efficiency. The S11 parameter is usually negative. The smaller the S11 parameter, the smaller the antenna return loss, the smaller the energy reflected back by the antenna itself, which means that in fact, the more energy enters the antenna, and the higher the system efficiency of the antenna; the larger the S11 parameter, the larger the antenna return loss, and the lower the system efficiency of the antenna.

[0108] It should be noted that in engineering, generally, the S11 value of -6 dB is used as the standard. When the S11 value of the antenna is less than -6 dB, it can be considered that the antenna can work normally, or it can be considered that the transmission efficiency of the antenna is good.

[0109] Smith Chart: A nomogram plotted with a family of constant normalized input impedance (or admittance) circles on the reflection coefficient plane. The chart consists of three families of circles and is used to solve problems in transmission lines and some waveguide problems by graphical methods to avoid cumbersome calculations.

[0110] Ground (GND): Generally refers to at least a part of any ground plane, ground plate, or ground metal layer in an electronic device (such as a mobile phone), or at least a part of any combination of the above ground planes, ground plates, or ground components. "Ground" can be used for grounding components in an electronic device. In one embodiment, "ground" can be the ground plane of the circuit board of the electronic device, or the ground plate formed by the middle frame of the electronic device, or the ground metal layer formed by the metal film under the screen. In one embodiment, the circuit board can be a printed circuit board (PCB), such as an 8-layer, 10-layer, or 12- to 14-layer board with 8, 10, 12, 13, or 14 layers of conductive material, or components separated and electrically insulated by dielectric or insulating layers such as fiberglass, polymers, etc. In one embodiment, the circuit board includes a dielectric substrate, a ground plane, and a trace layer, and the trace layer and the ground plane are electrically connected through vias. In one embodiment, components such as a display, a touch screen, input buttons, a transmitter, a processor, a memory, a battery, a charging circuit, a system on chip (SoC) structure, etc. can be mounted on the circuit board or connected to the circuit board; or electrically connected to the trace layer and / or the ground plane in the circuit board. For example, a radio frequency source is disposed on the trace layer.

[0111] Any of the above ground planes, ground plates, or ground metal layers is made of a conductive material. In one embodiment, the conductive material can be any one of the following materials: 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, cloth impregnated with graphite powder, a substrate coated with graphite, a copper-plated substrate, a brass-plated substrate, and an aluminum-plated substrate. Those skilled in the art can understand that the ground layer / ground plate / ground metal layer can also be made of other conductive materials.

[0112] Grounding: It refers to the coupling with the above-mentioned ground / floor through a grounding structure and / or a grounding circuit. In one embodiment, grounding can be achieved through physical grounding, such as through some structural components of the middle frame to achieve physical grounding at specific positions on the frame (or referred to as physical ground). In one embodiment, grounding can be achieved through device grounding, such as grounding through devices such as capacitors / inductors / resistors connected in series or in parallel (or referred to as device ground).

[0113] Distributed antenna system: It refers to a network composed of multiple spatially separated antenna elements connected to a common signal source through a transmission medium within a predetermined space.

[0114] Transmission line: It is a linear structure with specific parameters and characteristic impedance, such as a wire or a wire system, used to transmit electromagnetic energy. In a circuit, transmission lines include twisted pairs, coaxial cables, coplanar lines, microstrip lines, strip lines, etc. In fact, in an antenna system, as long as it is a position where a coupling capacitor is required to transmit energy, a transmission line structure can be applied, and it can have corresponding names, such as baluns, phase shifters, feeders, etc. In some cases, "transmission line" is narrowly understood as a linear structure used to connect different devices.

[0115] Characteristic impedance: It refers to the impedance of an infinitely long transmission line or the impedance of a transmission line without reflection. The characteristic impedance is related to the structural dimensions of the cross-section of the transmission line and has nothing to do with the length in the propagation direction. The characteristic impedance is usually expressed in units of ohm (physically represented as Ω). The characteristic impedance is an inherent property of the transmission line and is not affected by factors such as the amplitude and phase of the signal. In other words, on the same transmission line, the characteristic impedance is a constant value and will not change due to changes in signal amplitude and phase.

[0116] Figure 1 Fig. shows a schematic structural diagram of an electronic device to which the embodiments of the present application are applicable.

[0117] In the embodiments of the present application, the electronic device 100 is an electronic device with communication functions. The communication technologies adopted by the electronic device 100 include, but are not limited to, Bluetooth (BT) communication technology, Global Positioning System (GPS) communication technology, Wireless Fidelity (Wi-Fi) communication technology, Global System for Mobile Communications (GSM) communication technology, Wideband Code Division Multiple Access (WCDMA) communication technology, Long Term Evolution (LTE) communication technology, 5th-generation (5G) communication technology, SUB-6G communication technology (also known as low-to-medium frequency band spectrum communication technology or centimeter wave communication technology, where SUB-6G refers to the frequency band less than 6 GHz in 5G), millimeter wave (mmW) communication technology, 6th-generation (6G) communication technology, and other future communication technologies, etc.

[0118] The electronic device 100 in the embodiments of the present application can be a mobile phone, a personal digital assistant (PDA) computer, a tablet computer, a laptop computer, a laptop computer, an ultra-mobile personal computer (UMPC), a netbook, a smart watch, a smart wristband, an in-vehicle computer, a television (or smart screen), an augmented reality (AR) / virtual reality (VR) device, a wearable device, a wireless headset, etc., and can also be other handheld devices, computing devices with wireless communication functions, or processing devices connected to a wireless modem, in-vehicle devices, etc. The embodiments of the present application do not impose special restrictions on the specific form of the electronic device 100. For the convenience of description and understanding below, the electronic device 100 is taken as an example of a mobile phone for illustration.

[0119] As Figure 1 shown, the electronic device 100 may include: a cover 12, a display 13, a printed circuit board (PCB) 14, a middle frame 15, a rear cover 16, and an antenna 17.

[0120] The cover plate 12 can be disposed closely to the display screen 13, mainly for protecting the display screen 13 and preventing dust. In some embodiments, the cover plate 12 can be a cover glass, or can be replaced with a cover plate of other materials, such as a cover plate made of polyethylene terephthalate (PET) material, etc.

[0121] The display screen 13 is used for displaying images. In one embodiment, the display screen 13 can include a liquid crystal display (LCD) panel, a light emitting diode (LED) display panel, an organic light-emitting diode (OLED) display panel, an active-matrix organic light emitting diode (AMOLED) display panel, a flexible light-emitting diode (FLED) display panel, a quantum dot light emitting diode (QLED) display panel, etc., and the embodiments of the present application are not limited thereto.

[0122] The middle frame 15 is a support frame located inside the electronic device 100, mainly for supporting the whole machine. For example, the middle frame 15 can be used to support and fix the display screen 13. In one embodiment, the middle frame 15 can be formed of a metal material such as copper, magnesium alloy, stainless steel, etc.

[0123] The printed circuit board 14 is a support for electronic components and also serves as a carrier for electrical connection of electronic components. Here, the electronic components can include but are not limited to capacitors, inductors, resistors, processors, radio frequency chips, cameras, flashlights, microphones, batteries, etc. The printed circuit board 14 can adopt a flame-retardant material (FR-4) dielectric board, a Rogers dielectric board (a high-frequency board), or a hybrid dielectric board of Rogers and FR-4, etc.

[0124] In one embodiment, a metal layer may be provided on the printed circuit board 14. This metal layer can be used for grounding the electronic components carried on the printed circuit board 14, and can also be used for grounding other components, such as a bracket antenna, a frame antenna, etc. This metal layer can be referred to as a floor, or a ground plane, or a ground layer. In one embodiment, this metal layer can be formed by etching metal on the surface of any dielectric layer in the printed circuit board 14. In one embodiment, the metal layer for grounding can be provided on one side of the printed circuit board 14 close to the middle frame 15. In one embodiment, the edge of the printed circuit board 14 can be regarded as the edge of its ground layer. In one embodiment, the metal middle frame 15 can also be used for grounding the above-mentioned components. The electronic device 100 may also have other floors / ground planes / ground layers, as described above, which will not be elaborated here.

[0125] As Figure 1 shown, the printed circuit board 14 can be disposed between the middle frame 15 and the rear cover 16. In some other embodiments, the printed circuit board 14 can also be disposed between the middle frame 15 and the display screen 13, and the embodiments of the present application do not limit this.

[0126] In some embodiments, the electronic device 100 may further include a battery (not shown in the figure). The battery can be disposed between the middle frame 15 and the rear cover 16, or can be disposed between the middle frame 15 and the display screen 13, and the embodiments of the present application do not limit this. In some embodiments, the printed circuit board 14 can be divided into a main board and a daughter board, and the battery can be disposed between the main board and the daughter board. Among them, the main board can be disposed between the middle frame 15 and the upper edge of the battery, and the daughter board can be disposed between the middle frame 15 and the lower edge of the battery.

[0127] The electronic device 100 may further include a frame 11, and the frame 11 can be formed of a conductive material such as metal. The frame 11 can be disposed between the display screen 13 and the rear cover 16 and extend circumferentially around the periphery of the electronic device 100. The frame 11 can have four sides surrounding the display screen 13 to help fix the display screen 13.

[0128] In one implementation, the frame 11 made of a conductive material can be directly used as the conductive frame of the electronic device 100, for example, to form the appearance of a metal frame, which is suitable for metal industrial design (ID). In one embodiment, the outer surface of the frame 11 can be a conductive material. In one embodiment, the conductive part of the frame 11 can be used as the antenna radiator of the electronic device 100.

[0129] In another implementation, the outer surface of the frame 11 can also be made of a non-conductive material, such as a plastic frame, to form the appearance of a non-metallic frame, which is suitable for non-metallic IDs. In one embodiment, the inner surface of the frame 11 can include a conductive material, such as a metallic material. In this implementation, the conductive portion of the frame 11 can be used as the antenna radiator of the electronic device 100. It should be understood that the radiator disposed on the inner surface of the frame 11 (or rather, the conductive material on the inner surface) is arranged to fit the non-conductive material of the frame 11 to facilitate antenna radiation, and both the conductive material and the non-conductive material should be regarded as part of the frame 11.

[0130] In one embodiment, the middle frame 15 can include the frame 11. Here, the middle frame 15 including the frame 11, as an integral part, can support the electronic components in the whole machine. The cover plate 12 and the rear cover 16 are respectively closed along the upper and lower edges of the frame 11 to form the outer shell or housing of the electronic device 100. In one embodiment, the cover plate 12, the rear cover 16, the frame 11, and / or the middle frame 15 can be collectively referred to as the outer shell or housing of the electronic device 100. It should be understood that the "outer shell or housing" can be used to refer to part or all of any one of the cover plate 12, the rear cover 16, the frame 11, or the middle frame 15, or refer to part or all of any combination of the cover plate 12, the rear cover 16, the frame 11, or the middle frame 15.

[0131] In some embodiments, the frame 11 on the middle frame 15 can at least partially serve as an antenna radiator to receive / transmit radio frequency signals. There can be a gap between this part of the frame serving as the radiator and the other parts of the middle frame 15, so as to ensure that the antenna radiator has a good radiation environment. In one embodiment, the middle frame 15 can be provided with apertures at this part of the frame serving as the radiator to facilitate the radiation of the antenna.

[0132] In another embodiment, the frame 11 may not be regarded as part of the middle frame 15. For example, the frame 11 can be connected to and integrally formed with the middle frame 15. Alternatively, the frame 11 can include a protruding member extending inward to be connected to the middle frame 15. For example, the protruding member is connected to the middle frame 15 by means of a spring piece, a screw, welding, etc. Exemplarily, the protruding member of the frame 11 can also be used to receive a feeding signal, so that at least a part of the frame 11 serves as the radiator of the antenna to receive / transmit radio frequency signals. There can be a gap between this part of the frame serving as the radiator and the middle frame 15, so as to ensure that the antenna radiator has a good radiation environment and the antenna has a good signal transmission function.

[0133] The rear cover 16 is usually disposed on the back of the electronic device 100, for example, on the side of the middle frame 15 facing away from the display screen 13. The rear cover 16 is mainly used to protect the components inside the electronic device 100. For example, it can prevent external impurities such as dust and water stains from entering the inside of the electronic device 100. In some embodiments, the rear cover 16 can also be used to fix other display screens except the display screen 13, or to fix antennas, etc. The rear cover 16 can be a rear cover made of a metal material; it can also be a rear cover made of a non-conductive material, such as a glass rear cover, a plastic rear cover and other non-metal rear covers; it can also be a rear cover made of both conductive material and non-conductive material. In one embodiment, the rear cover 16 including the conductive material can replace the middle frame 15 and, together with the frame 11, serve as a single piece to support the electronic components in the whole machine.

[0134] In one embodiment, the middle frame 15 and / or the conductive part of the rear cover 16 can be used as the reference ground of the electronic device 100. Among them, the frame 11, the printed circuit board 14, etc. of the electronic device 100 can be grounded by electrically connecting to the middle frame 15.

[0135] The antenna 17 is used to implement the communication function of the electronic device 100. When transmitting a signal, the electronic device 100 mainly outputs the radio frequency signal power through the radio transmitter, and then conveys it to the antenna 17 through the feeder, and the antenna 17 radiates it in the form of electromagnetic waves. When receiving a signal, the antenna 17 receives the electromagnetic waves in space and conveys them to the radio receiver through the feeder.

[0136] In one embodiment, the antenna 17 can be disposed inside the frame 11. When the frame 11 of the electronic device 100 is made of a non-conductive material, the antenna radiator can be located inside the electronic device 100 and disposed along the frame 11. For example, the antenna radiator is disposed close to the frame 11 to minimize the volume occupied by the antenna radiator and be closer to the outside of the electronic device 100 to achieve a better signal transmission effect. It should be noted that the antenna radiator being disposed close to the frame 11 means that the antenna radiator can be disposed closely to the frame 11 or be disposed close to the frame 11. For example, there can be a certain small gap between the antenna radiator and the frame 11.

[0137] In one embodiment, the antenna 17 can be disposed inside the housing, such as a bracket antenna, a millimeter wave antenna, etc.( Figure 1(not shown in the figure). The clearance for the antenna disposed within the housing can be obtained by a slit / aperture on any one of the middle frame 15, and / or the side frame 11, and / or the rear cover 16, and / or the display screen 13, or by a non-conductive gap / aperture formed between any several of them. The setting of the clearance for the antenna can ensure the radiation characteristics of the antenna. It should be understood that the clearance for the antenna can be a non-conductive area formed by any conductive component within the electronic device 100, and the antenna radiates signals to the external space through this non-conductive area. In some embodiments, the form of the antenna 17 can be an antenna form based on a flexible printed circuit (FPC), an antenna form based on laser-direct-structuring (LDS), or an antenna form such as a microstrip disk antenna (MDA), a slot antenna, etc. In some embodiments, the antenna 17 can also adopt a transparent structure embedded inside the screen of the electronic device 100, such that the antenna 17 is a transparent antenna unit embedded inside the screen of the electronic device 100.

[0138] Exemplarily, when the antenna 17 is a wire antenna, the radiator of the antenna 17 can be an additionally provided metal sheet, or a metal trace formed by laser on an insulating material (such as a dielectric substrate, a plastic bracket) on the electronic device 100, or the metal side frame of the electronic device 100. Among them, the antenna 17 can be a stick-on type, for example, directly sticking the metal sheet on the insulating material of the electronic device (such as an insulating side frame, a dielectric substrate, etc.), or directly laser-etching the metal trace on the insulating material of the electronic device. The antenna 17 can also be a bracket type, for example, fixing the metal sheet to the plastic bracket, or laser-etching the metal trace on the plastic bracket and then fixing the plastic bracket to the inner side of the housing. When the antenna 17 is a slot antenna (i.e., a slotted antenna), a slot can be directly opened on a waveguide, a metal plate (such as the ground plane of the printed circuit board 14, a metal middle frame, a metal rear cover, etc.), a coaxial cable, or a resonant cavity, and the electromagnetic wave radiates to the external space through the slot.

[0139] Figure 1 Only some components included in the electronic device 100 are schematically shown, and the actual shape, actual size, and actual structure of these components are not limited by Figure 1 the description. In some other embodiments, the electronic device 100 may further include more or fewer components than those shown in the figure, which is not limited in the embodiments of the present application. In some other embodiments, the types of the electronic device 100 are different, and the components included therein are different. The electronic device structure provided in the embodiments of the present application is only for exemplary illustration.

[0140] It should be understood that in the embodiments of the present application, the surface where the display screen 13 of the electronic device 100 is located can be regarded as the front surface, the surface where the rear cover 16 is located can be regarded as the back surface, and the surface where the side frame 11 is located can be regarded as the side surface.

[0141] It should be understood that in the embodiments of the present application, when the user holds the electronic device 100 (usually vertically and facing the screen), the electronic device 100 has orientations such as a top, a bottom, a left side, and a right side.

[0142] As described above, the electronic device can implement a communication function through an antenna. Generally speaking, the signal transmission ability of the antenna highly depends on the matching degree of the antenna. Specifically, the better the antenna matching, the less signal reflection and the more signal transmission. Antenna matching is a process to ensure the maximum power transmission between the antenna and the transmission line or the radio frequency circuit in the radio frequency system. The goal of antenna matching is to match the input impedance (or called feeding impedance) of the antenna with the output impedance (referring to the characteristic impedance of the radio frequency circuit or the transmission line) of the system, so as to minimize the reflection loss and ensure that as much radio frequency energy as possible is transmitted into the antenna.

[0143] With the increasing demand for high-speed data transmission by people, the industrial design (ID) of electronic devices has developed towards a trend of large screen ratio and multiple cameras, which has also caused a significant reduction in the antenna clearance, and the layout space is becoming more and more limited. Currently, a distributed antenna design is mostly adopted, and multiple radiators connected to the same signal source are arranged in the electronic device to transmit radio frequency signals. In this way, there are more degrees of freedom to design the antenna to adapt to the layout space of the electronic device. However, the matching effect of the existing distributed antennas is not good, and a lot of electromagnetic waves are reflected back to the radio frequency chip instead of being transmitted, resulting in a low signal transmission ability.

[0144] In view of this, the present application provides an antenna structure that can be arranged in an electronic device with limited space and can have good matching, thereby improving the signal transmission ability.

[0145] Figure 2 A schematic diagram of an antenna structure provided by an embodiment of the present application is shown. Figure 2 The shown antenna structure 200 can be applied to Figure 1 the shown electronic device 100, and this antenna structure 200 can be Figure 1 an example of the shown antenna 17.

[0146] As Figure 2As shown, the antenna structure 200 may include n antenna units, such as antenna unit 1, antenna unit 2, antenna unit 3, …, antenna unit n - 1, antenna unit n. Each of the n antenna units is connected to a transmission line, and there are a total of n transmission lines. For example, antenna unit 1, antenna unit 2, antenna unit 3, …, antenna unit n - 1, antenna unit n are respectively connected to transmission line 1, transmission line 2, transmission line 3, …, transmission line n - 1, transmission line n. After being combined at the combining point, the n transmission lines are electrically connected to the signal line. Taking one of the n transmission lines as an example, one end of this transmission line is electrically connected to the corresponding antenna unit, and the other end is electrically connected to the ends of other transmission lines at the combining point. After the n transmission lines are combined at the combining point, they are then electrically connected to the signal line. In this application, the combining point may also be referred to as the synthesis point.

[0147] The n transmission lines are arranged in the order of the magnitudes of the first phase values. Each transmission line corresponds to a first phase value, and the first phase value corresponding to a transmission line is the value obtained by taking the remainder of the absolute phase of this transmission line with respect to 180°. That is to say, the n transmission lines are arranged in the order of the values obtained by taking the remainder of the absolute phase with respect to 180°. Among them, the difference between the first phase value corresponding to the k-th transmission line among the n transmission lines and the first phase value corresponding to the (k + 1)-th transmission line among the n transmission lines is 180° / n ± 180° / 2n. For ease of description, in this application, the difference between the first phase values corresponding to two transmission lines is referred to as the transmission phase difference. Specifically, the difference between the first phase value corresponding to the k-th transmission line and the first phase value corresponding to the (k + 1)-th transmission line is the transmission phase difference between the k-th transmission line and the (k + 1)-th transmission line.

[0148] Each of the n transmission lines has a characteristic impedance. For example, the characteristic impedances of transmission line 1, transmission line 2, transmission line 3, …, transmission line n - 1, transmission line n are Z11, Z12, Z13, …, Z1 n-1 , Z1 n . The output impedance of the combining point is less than the characteristic impedance of the transmission line with the smallest characteristic impedance among the n transmission lines. For example, the output impedance of the combining point is Z2, that is, Z2 < min(Z11, Z12, Z13, …, Z1 n-1 , Z1 n ). Here, n ≥ 2, k ≥ 1 and k < n, and both n and k are integers.

[0149] In the embodiments of this application, both the signal line and the transmission line are used to transmit signals (or referred to as feeding). Among them, the signal line is used to feed the n antenna units, and each transmission line is used to feed the antenna unit connected thereto.

[0150] In the embodiments of the present application, the arrangement order of the n transmission lines can be understood as the logical arrangement order, which is decoupled from the physical arrangement order. That is to say, the present application does not limit the physical arrangement order of the n transmission lines.

[0151] In the embodiments of the present application, after passing through the transmission lines with a phase difference of 180 / n ± 180° / 2n, the antenna unit can be transformed into an impedance value different from the antenna impedance of the antenna unit itself, showing both inductive and capacitive phenomena. When n antenna units are connected in parallel, the inductance and capacitance of different antenna units can cancel each other out, so as to form an input impedance with smaller inductance and capacitance at the combining point, that is, the imaginary part of the impedance is close to zero, and the real part of the impedance is smaller, which is beneficial to obtaining good impedance matching and further improving the signal transmission ability.

[0152] As Figure 2 shown, in the embodiments of the present application, the impedance of the combining point includes an input impedance and an output impedance. The input impedance of the combining point is the impedance obtained by connecting n antenna units in parallel at the combining point after passing through the transmission lines. Specifically, the input impedance of the combining point is the ratio of the voltage to the current when looking from the combining point towards the antenna unit side. The output impedance of the combining point is the impedance obtained when the signal line reaches the combining point. Specifically, the output impedance of the combining point is the ratio of the voltage to the current when looking from the combining point towards the signal line (i.e., the signal source) side. The output impedance of the combining point can be determined according to the characteristic impedance of the signal line. For example, if the signal line is directly connected to the combining point, the output impedance of the combining point is the characteristic impedance of the signal line. Another example is that if there is an impedance transformer between the signal line and the combining point, the output impedance of the combining point is the impedance of the characteristic impedance of the signal line after passing through the impedance transformer. The input impedance of the combining point is a complex value, and the output impedance of the combining point is a real number. When the impedance matching is good, the imaginary part of the input impedance is close to 0, and the real part of the input impedance is close to or equal to the output impedance. When the input impedance and the output impedance of the combining point are matched, better signal transmission performance can be obtained.

[0153] In some embodiments, the n transmission lines are directly connected to the signal line after being combined at the combining point. That is to say, the signal line is divided into n transmission lines at the combining point to connect n antenna units. Correspondingly, the signal transmitted by the signal line is transmitted to the corresponding antenna unit through the n transmission lines at the combining point. In this way, while obtaining a good matching effect, the antenna structure is simple and easy to be arranged in an electronic device with limited space.

[0154] Exemplarily, taking n = 2 as an example, Figure 3 shows a schematic diagram of an antenna structure provided by the embodiments of the present application. As Figure 3As shown, the antenna structure 300 may include antenna unit 1 and antenna unit 2. Antenna unit 1 is connected to transmission line 1, and antenna unit 2 is connected to transmission line 2. After being combined at the combining point 301, transmission line 1 and transmission line 2 are connected to signal line 302.

[0155] The signal line 302 for feeding is connected to antenna unit 1 and antenna unit 2 through two transmission lines (i.e., transmission line 1 and transmission line 2). The reflection coefficient of the combined antenna (i.e., antenna unit 1 and antenna unit 2 working together) is less than that of a single antenna (such as antenna unit 1 or antenna unit 2), so that the matching can be optimized and the system efficiency can be improved.

[0156] It can be understood that the single antenna involved in the embodiments of the present application can be understood as an antenna structure including one or more antenna units, and the one or more antenna units are respectively connected to feed lines to independently feed each antenna unit. The combined antenna involved in the embodiments of the present application can be understood as an antenna structure including multiple antenna units, and the multiple antenna units are fed through the same signal source, that is, a distributed antenna.

[0157] For ease of understanding, some specific non-limiting examples of the present application will be further described below.

[0158] Figure 4 shows a schematic diagram of an antenna structure provided by an embodiment of the present application. As Figure 4 shown, the antenna structure 400 includes antenna unit 1 and antenna unit 2. Antenna unit 1 and antenna unit 2 are wire antennas (for example, the radiator is L-shaped). Antenna unit 1 is connected to transmission line 1, and antenna unit 2 is connected to transmission line 2. Transmission line 1 and transmission line 2 are combined at the combining point 301 and electrically connected to signal line 302.

[0159] As an example but not a limitation, the characteristic impedance of transmission line 1 is the same as that of transmission line 2, both being Z0 = 100 ohms. The transmission phase difference between transmission line 1 and transmission line 2 is 90° (i.e., 180° / 2). The characteristic impedance Z3 of signal line 302 is 50 ohms, which is half of the characteristic impedance of transmission line 1 or transmission line 2. Signal line 302 is directly connected to the combining point 301, and the output impedance Z2 of the combining point 301 is also 50 ohms. For convenience, the above relevant parameters are shown in Table 1 below.

[0160] Table 1

[0161]

[0162] Figure 5 shows Figure 4 two possible circuit connection schematic diagrams of the antenna structure 400 in Figure 5The difference between the circuit connection diagrams shown in (a) and (b) lies in the absolute phases of the transmission lines. Specifically, Figure 5 In the circuit connection diagram shown in (a), the absolute phase of transmission line 1 is 0° (the physical length of transmission line 1 is 0), and the absolute phase of transmission line 2 is 90°. Figure 5 In the circuit connection diagram shown in (b), the absolute phase of transmission line 1 is 30°, and the absolute phase of transmission line 2 is 120°. However, Figure 5 In the two circuit connection schemes shown, the difference between the absolute phase of transmission line 1 and the absolute phase of transmission line 2 (i.e., the transmission phase difference, also known as the relative phase or phase difference) is 90°.

[0163] Figure 6 shows Figure 4 the polar plot of the reflection coefficient of the antenna structure 400 shown connected to the circuit 1 as Figure 5 shown.

[0164] The polar plot of the reflection coefficient includes two parameters: the linear magnitude and the phase value. The curves shown in the figure are the results of the reflection coefficient at various frequencies. If the magnitude is expressed in dB, the conversion formula with the linear magnitude is 20log10(linear magnitude). For example Figure 6 in (a), when the linear magnitude is 0.7, the magnitude approximately corresponds to -3 dB; again, Figure 6 in (b), when the linear magnitude is 0.5, the magnitude approximately corresponds to -6 dB.

[0165] Figure 6 (a) shows a schematic diagram of the initial matching result of the antenna structure 400. It should be noted that the initial matching result involved in this application can be understood as the matching result of a single antenna. Exemplarily, Figure 6 in (a) shows the initial matching result obtained when the antenna element 1 (or antenna element 2) is fed by a 100-ohm transmission line, that is, the reflection coefficient situation. According to Figure 6 shown in (a), the reflection coefficient of a single antenna (such as antenna element 1 or antenna element 2) is less than -3 dB.

[0166] Figure 6 (b) shows a schematic diagram of the combined matching result of the antenna structure 400. It should be noted that the combined matching result involved in this application can be understood as the matching result of a combined antenna. Exemplarily, Figure 6 in (b) shows the combined matching result obtained when the antenna element 1 is fed by a 100-ohm transmission line and the antenna element 2 is fed by a 100-ohm transmission line. According to Figure 6 shown in (b), the reflection coefficient of the combined antenna is less than -6 dB.

[0167] Figure 7 Shown Figure 4 The antenna structure 400 shown is Figure 5 The S parameter simulation results of the circuit 1 are shown. Figure 7 In the figure, the dotted line is the curve of S11 parameter of a single antenna changing with frequency, and the solid line is the curve of S11 parameter of a composite antenna changing with frequency. Figure 7 As shown, the S11 of a single antenna (such as antenna unit 1 or antenna unit 2) in the working frequency band (about 0.9 GHz-1.05 GHz) is less than -3 dB, and the S11 of the combined antenna in the working frequency band (about 0.9 GHz-1.05 GHz) is less than -6 dB.

[0168] according to Figure 6 and Figure 7 It can be seen that antenna unit 1 and antenna unit 2 are discrete antennas (i.e., the radiators are discrete). When the reflection coefficient of antenna unit 1 or antenna unit 2 is -XdB, the reflection coefficient of the composite antenna can be increased to -2XdB, thereby optimizing matching and improving system efficiency.

[0169] Figure 8 Shown Figure 4 The antenna structure 400 shown is Figure 5 The matching result diagram of circuit 2 is shown. Figure 8 (a) is a Smith chart of the antenna structure 400, which represents the inductance, capacitance, and resistance characteristics of the reflection coefficient from an impedance perspective, and can facilitate engineers to perform subsequent matching optimization. Figure 8 (b) in FIG is a polar coordinate diagram of the reflection coefficient of the antenna structure 400, which makes it easy to see the magnitude of the reflection coefficient. Figure 8 As shown in (a) and (b) in FIG. 1 , the antenna structure 400 is Figure 5 The reflection coefficient of the composite antenna formed by the connection of the circuit 2 shown is less than -6dB.

[0170] Figure 9 Shown Figure 4 The antenna structure 400 shown is Figure 5 The S parameter simulation results of the circuit 2 are shown. Figure 9 In the figure, the solid line is the curve of the S11 parameter of the synthetic antenna changing with frequency. ​ As shown, the S11 of the composite antenna in the working frequency band (about 0.9 GHz-1.05 GHz) is less than -6 dB.

[0171] according to ​It can also be seen that although the absolute phase of the transmission line is different when the antenna structure 400 is connected according to Circuit 1 and Circuit 2, the S11 depth result corresponding to Circuit 1 is the same as the S11 depth result corresponding to Circuit 2. That is, the composite matching result of the antenna structure provided in the embodiments of the present application is not affected by the absolute phase of the transmission line. Thus, when performing impedance matching and matching optimization, it is only necessary to control the relative phase between the pairs of transmission lines connected to the antenna elements, and there is no need to precisely control the absolute phase of the transmission line.

[0172] It can be understood that ​ in the shown antenna structure 400, the design parameters of the antenna element, such as the length from the open end of the radiator to the ground point, the distance from the feeding point to the ground point, etc., and the circuit connection method can be designed according to actual requirements, and the present application does not make any limitations here. It can also be understood that ​ the form of the shown wire antenna element is only exemplary. In some other embodiments, the antenna element can also adopt other forms of wire antennas, which will not be described one by one here.

[0173] In some other embodiments, in the antenna structure 400, the transmission phase difference between Transmission Line 1 and Transmission Line 2 can also be other values, such as 90°±45°.

[0174] ​ shows ​ the S-parameter simulation results of the antenna structure 400 in at different transmission phase differences.

[0175] According to ​ it can be known that the S11 of a single antenna (such as Antenna Element 1 or Antenna Element 2) is less than -3 dB in the operating frequency band (about 0.9 GHz - 1.05 GHz). When the phase difference between Transmission Line 1 and Transmission Line 2 is 90°, the S11 of the composite antenna in this operating frequency band is less than -6 dB, and the optimization matching effect is the best. When the phase difference between Transmission Line 1 and Transmission Line 2 is 45°, the S11 of the composite antenna in this operating frequency band is less than the S11 result corresponding to the single antenna, and there is still an optimization matching effect. When the phase difference between Transmission Line 1 and Transmission Line 2 is 135°, the S11 of the composite antenna in this operating frequency band is less than the S11 result corresponding to the single antenna, and there is still an optimization matching effect. In other words, when the phase difference between Transmission Line 1 and Transmission Line 2 is within the range of 45° - 135°, the composite antenna can operate within the designed operating frequency band.

[0176] In addition, when the phase difference is 45°, 90°, and 135°, the operating bandwidths corresponding to the case where the S11 of the combined antenna is less than -6 dB are approximately equal, about 150 MHz. That is to say, the operating bandwidth of the combined antenna will not be significantly reduced due to the change in the phase difference between the transmission lines, which can meet the required transmission bandwidth of the signal. Although the optimal operating frequency bands of the combined antenna in the above three cases have deviations. For example, the optimal operating frequency bands of the combined antennas with phase differences of 45° and 135° are frequency-offset relative to the designed operating frequency band (about 0.9 GHz - 1.05 GHz), but in practical applications, the optimal operating frequency band can be adjusted to the designed operating frequency band by other means (such as fine-tuning the antenna size).

[0177] In some other embodiments, in the antenna structure 400, the characteristic impedance of transmission line 1 and the characteristic impedance of transmission line 2 may also be unequal. For example, the characteristic impedance of transmission line 1 is greater than the characteristic impedance of transmission line 2, or the characteristic impedance of transmission line 1 is less than the characteristic impedance of transmission line 2.

[0178] ​ Shows ​ The S-parameter simulation results of the antenna structure 400 in

[0179] According to ​ It can be known that when the characteristic impedance of the feeder line feeding the individual antenna is 100 ohms, the S11 of the individual antenna (such as antenna element 1 or antenna element 2) is less than -3 dB in the operating frequency band (about 0.9 GHz - 1.05 GHz). When the characteristic impedances of both transmission line 1 and transmission line 2 are 100 ohms, the S11 of the combined antenna in this operating frequency band is less than -6 dB, and the optimal matching effect is the best. When the characteristic impedance of transmission line 1 is 80 ohms and the characteristic impedance of transmission line 2 is 100 ohms, the S11 of the combined antenna in this operating frequency band is less than the S11 result corresponding to the individual antenna, and there is still an optimal matching effect. When the characteristic impedance of transmission line 1 is 100 ohms and the characteristic impedance of transmission line 2 is 120 ohms, the S11 of the combined antenna in this operating frequency band is less than the S11 result corresponding to the individual antenna, and there is still an optimal matching effect. In other words, whether the characteristic impedance of transmission line 1 is equal to or unequal to the characteristic impedance of transmission line 2, the combined antenna can operate within the designed operating frequency band.

[0180] In addition, when the characteristic impedances of transmission line 1 and transmission line 2 change, the operating bandwidth and frequency range corresponding to the case where the S11 of the combined antenna is less than -6 dB are approximately equal, which can meet the required transmission bandwidth and transmission frequency of the signal.

[0181] In some other embodiments, in the antenna structure 400, the characteristic impedance of the signal line (or the output impedance of the combining point) can also be other values less than 100 ohms.

[0182] ​ shows ​ the simulation results of the S-parameters of the antenna structure 400 in

[0183] According to ​ it can be known that when the characteristic impedance of the feeder line feeding the individual antenna is 100 ohms, the S11 of the individual antenna (such as antenna element 1 or antenna element 2) in the operating frequency band (about 0.9 GHz - 1.05 GHz) is less than -3 dB. When the characteristic impedance of the signal line is 50 ohms, the S11 of the combined antenna in this operating frequency band is less than -6 dB, and the optimized matching effect is the best. When the characteristic impedance of the signal line is 75 ohms, the S11 of the combined antenna in this operating frequency band is less than -5 dB, and there is still an optimized matching effect compared with the S11 result of the individual antenna.

[0184] In addition, when the characteristic impedance of the signal line changes, the operating bandwidth and frequency range corresponding to the combined antenna when S11 is less than -6 dB are approximately equal, so that the required transmission bandwidth and transmission frequency of the signal can be satisfied.

[0185] Return reference ​ , in some embodiments, the antenna structure 200 may further include a matching network 210, and the matching network 210 is disposed between the combining point and the signal line. By adding the matching network 210 before connecting the signal line, the matching can be further optimized. The following combines ​ to illustrate the optimized matching effect of the matching network 210 by way of example.

[0186] As an example but not a limitation, still taking n = 2 as an example, as ​ shown, antenna element 1 and antenna element 2 are patch antennas (such as 1 / 4-wavelength patch antennas, specifically referring to the electrical length from the ground end to the open end of the patch antenna being close to 1 / 4 of the antenna operating wavelength, where the operating wavelength refers to the wavelength corresponding to the center of the antenna operating frequency). ​ In (a) shown in ​ is a schematic diagram of an individual antenna. Specifically, antenna element 1 and antenna element 2 are two independent antennas. Antenna element 1 is fed by a 100-ohm feeder line, and antenna element 2 is fed by a 100-ohm feeder line. ​As shown in (c) therein, the synthetic antenna with a matching network is presented. Specifically, antenna element 1 is connected to transmission line 1 with a characteristic impedance of 100 ohms, and antenna element 2 is connected to transmission line 2 with a characteristic impedance of 100 ohms. After the combination of transmission line 1 and transmission line 2, they are connected to a matching network, and the matching network is then connected to a signal line with a 50-ohm impedance. The transmission phase difference between transmission line 1 and transmission line 2 is 90°.

[0187] ​ shows ​ a schematic diagram of the matching result of the single antenna shown in (a) therein. ​ In (a) and (b) therein, respectively, show ​ the polar plot of the reflection coefficient and the S-parameter simulation result of the single antenna shown. According to ​ it can be known that S11 of antenna element 1 is less than -1 dB in the operating frequency band (about 6 GHz - 7 GHz), and S11 of antenna element 2 is less than -1 dB in the operating frequency band (about 6 GHz - 7 GHz).

[0188] ​ shows ​ a schematic diagram of the matching result of the synthetic antenna without a matching network shown in (b) therein. ​ In (a) and (b) therein, respectively, show ​ the Smith chart and the S-parameter simulation result of the synthetic antenna without a matching network shown. According to ​ it can be known that S11 of the synthetic antenna is less than -2 dB in the operating frequency band (about 6 GHz - 7 GHz). Compared with the single antenna, the matching is optimized.

[0189] ​ shows ​ a schematic diagram of the matching result of the synthetic antenna with a matching network shown in (c) therein. ​ In (a) and (b) therein, respectively, show ​ the Smith chart and the S-parameter simulation result of the synthetic antenna without a matching network shown. According to ​It can be known that the S11 of the combined antenna at the same operating frequency band (about 6 GHz - 7 GHz) is less than -3 dB. Compared with the combined antenna without a matching network, the impedance matching is further optimized. Of course, from another perspective, when the matching results are similar, the bandwidth of the combined antenna with a series matching network is extended compared to that of the combined antenna without a matching network. For example, when the reflection coefficient is less than -2 dB, the operating bandwidth of the combined antenna without a matching network is about 6 GHz - 7 GHz, while the operating bandwidth of the combined antenna with a matching network can be extended to 5.9 GHz - 7.1 GHz. Another example is that when the reflection coefficient is less than -3 dB, the operating bandwidth of the combined antenna without a matching network is about 6.1 GHz - 6.8 GHz, while the operating bandwidth of the combined antenna with a matching network can be extended to 6 GHz - 7 GHz. In addition, the series matching network (such as devices and / or traces) can also form double resonances. For example ​ as shown in (b) of

[0190] the combined antenna can generate a first resonance near 6.2 GHz and a second resonance near 6.8 GHz. In some embodiments, the output impedance of the combining point (such as combining point 301) is the characteristic impedance of the signal line (such as signal line 302). For example, when n transmission lines are directly connected to the signal line after being combined at the combining point, or when n transmission lines are first connected to a matching network and then to the signal line after being combined at the combining point, the characteristic impedance of the signal line can be used as the output impedance of the combining point. This is beneficial for directly and naturally obtaining impedance matching.

[0191] Correspondingly, the characteristic impedance of the signal line is less than the characteristic impedance of the transmission line with the smallest characteristic impedance among the n transmission lines.

[0192] In other embodiments, the output impedance of the combining point may not be equal to the characteristic impedance of the signal line either. For example, the output impedance of the combining point is greater than or less than the characteristic impedance of the signal line. In one embodiment, referring back ​ the antenna structure 200 may include an impedance transformer 220, which is disposed between the combining point and the signal line and is used for impedance transformation between the combining point and the signal line. The output impedance of the combining point can be the impedance after the characteristic impedance of the signal line is transformed by the impedance transformer 220.

[0193] Exemplarily, taking n = 2 as an example, ​ a schematic diagram of an antenna structure provided by an embodiment of the present application is shown. As ​ shown, the antenna structure 500 may include an antenna unit 1 and an antenna unit 2. The antenna unit 1 is connected to a transmission line 1, and the antenna unit 2 is connected to a transmission line 2. The transmission line 1 and the transmission line 2 are combined at the combining point 301 and then connected to the impedance transformer 220, and the impedance transformer 220 is then connected to the signal line 302.

[0194] By way of example and not limitation, the characteristic impedance of transmission line 1 is the same as that of transmission line 2, both being Z0 = 100 ohms. The transmission phase difference between transmission line 1 and transmission line 2 is 90°. The output impedance Z2 of the combining point 301 is 50 ohms, which is half of the characteristic impedance of transmission line 1 or transmission line 2. The impedance transformer 220 is a 1 / 4 wavelength impedance transformer (i.e., the electrical length of the impedance transformer is 1 / 4 of the wavelength corresponding to the center frequency of the antenna), and its characteristic impedance Z4 is The characteristic impedance Z3 of the signal line 302 is the same as the characteristic impedance of transmission line 1 / transmission line 2, also being 100 ohms. For convenience, the above relevant parameters are shown in Table 2 below.

[0195] Table 2

[0196]

[0197] In this embodiment, the characteristic impedance Z4 of the 1 / 4 wavelength impedance transformer can be calculated by the following formula: Z4 2 = Z3 * Z2. It should be understood that for different types of impedance transformers, the calculation methods of the characteristic impedance are different. This is only for illustrative purposes and the present application is not limited thereto.

[0198] In the embodiment of the present application, by adding an impedance transformer between the signal line 302 and the combining point 301, impedance transformation can be performed between the combining point 301 and the signal line 302. In this way, the characteristic impedance of the signal line 302 can be decoupled from the output impedance of the combining point 301, that is, the characteristic impedance of the signal line 302 can be decoupled from the characteristic impedance of the transmission line. For example, through impedance transformation, the characteristic impedance of the signal line 302 can be the same as or different from the characteristic impedance of the transmission line.

[0199] In some embodiments, the characteristic impedance of the signal line 302 is greater than or equal to the characteristic impedance of the transmission line with the smallest characteristic impedance among n transmission lines. Exemplarily, the characteristic impedance value of each of the n transmission lines is a first value, and the characteristic impedance of the signal line 302 is a third value, and the third value can be equal to the first value. In other words, when the characteristic impedances of the n transmission lines are all the same, the characteristic impedance of the signal line 302 can be equal to the characteristic impedance of the transmission line.

[0200] In some embodiments, the number of sections of the impedance transformer 220 can be one or more. The impedance transformer with one section has a simple structure, and the impedance transformer with multiple sections can obtain impedance transformation in a wide frequency band.

[0201] Exemplarily, when the number of sections of the impedance transformer 220 is one, the impedance transformer 220 can be a quarter-wavelength impedance transformer. When the number of sections of the impedance transformer 220 is multiple, the impedance transformer 220 can be a Chebyshev impedance transformer.

[0202] As mentioned above, the output impedance of the combining point 301 is less than the characteristic impedance of the transmission line with the smallest characteristic impedance among the n transmission lines. Exemplarily, when the characteristic impedance of each of the n transmission lines is a first value and the output impedance of the combining point 301 is a second value, the second value can be 1 / n of the first value. Correspondingly, when the output impedance of the combining point 301 is the characteristic impedance of the signal line, the characteristic impedance of the signal line is the second value, that is, the characteristic impedance of the signal line is 1 / n of the characteristic impedance of the transmission line.

[0203] Return to reference ​ , in the embodiments of the present application, the form of the antenna element in the antenna structure 200 can be various. For example, it can be a wire antenna, a patch antenna, a slot antenna, etc.

[0204] As an example, taking one antenna element (hereinafter referred to as the first antenna element) among the n antenna elements as an example, the first antenna element can be a wire antenna, for example, it can be an L-shaped wire antenna as ​ shown. The L-shape involved here can be understood as that the radiator of the first antenna element is in an L-shape.

[0205] As another example, the first antenna element can be a patch antenna. The patch antenna is small in size and light in weight, and is more flexible in terms of space utilization. In addition, the patch antenna can be designed with different sizes and shapes according to different application requirements, so as to be applicable to different frequency ranges.

[0206] In one implementation, the first antenna element can include a first patch and a second patch arranged side by side. The first patch includes a first open end and a first ground end, and the second patch includes a second open end and a second ground end. Wherein, the second ground end rotates 90° relative to the first ground end, the second open end rotates 90° relative to the first open end, and the rotation directions of the second open end and the second ground end are the same. The first antenna element includes two patches, which can form double resonance, thereby expanding the working bandwidth of the antenna.

[0207] Exemplarily, ​ shows a schematic diagram of an antenna structure provided by the embodiments of the present application. As ​As shown, the antenna structure 600 includes antenna element 1 and antenna element 2, and antenna element 1 and antenna element 2 are patch antennas. Among them, antenna element 1 includes a first patch and a second patch arranged side by side, and antenna element 2 includes a first patch and a second patch arranged side by side. The first patch has a grounding end (referred to as the first grounding end in this application) and an open end (referred to as the first open end in this application), the second patch has a grounding end (referred to as the second grounding end in this application) and an open end (referred to as the second open end in this application), and the second patch is rotated 90° relative to the first patch. Specifically, the second grounding end is rotated 90° relative to the first grounding end, the second open end is rotated 90° relative to the first open end, and the rotation directions of the second open end and the second grounding end are the same. Here, both antenna element 1 and antenna element 2 are examples of the first antenna element. Antenna element 1 is connected to transmission line 1, and antenna element 2 is connected to transmission line 2. After transmission line 1 and transmission line 2 are combined, they are electrically connected to the signal line.

[0208] By way of example and not limitation, the characteristic impedance of transmission line 1 is the same as that of transmission line 2, both being Z0 = 100 ohms. The transmission phase difference between transmission line 1 and transmission line 2 is 90° (i.e., 180° / 2). The characteristic impedance Z3 of the signal line is also 50 ohms, which is half of the characteristic impedance of transmission line 1 or transmission line 2, and the signal line is directly connected to the combining point.

[0209] Taking the first patch and the second patch as 1 / 4 wavelength patches as an example, ​ shows ​ a schematic diagram of the matching result of the antenna structure shown. ​ In (a) and (b) respectively show the Smith chart and S-parameter simulation results of the antenna structure 600. According to ​ it can be known that the S11 of the antenna structure 600 in the operating frequency band (about 6 GHz - 7.2 GHz) is less than -4 dB. In addition, the antenna structure 600 can form double resonances. For example, ​ as shown in (b), the antenna structure 600 can generate a first resonance near 6.2 GHz and a second resonance near 7.0 GHz.

[0210] In order to compare the matching results, ​ shows a schematic diagram of the matching result of the corresponding individual antennas of the antenna structure 600 (for example, antenna element 1 and antenna element 2 are fed separately). ​ In (a) and (b) respectively show the polar plot of the reflection coefficient of the individual antenna and the S-parameter simulation results. According to ​It can be known that the S11 of antenna unit 1 is less than -2 dB in the operating frequency band (about 6 GHz - 7.2 GHz), and the S11 of antenna unit 2 is less than -2 dB in the operating frequency band (about 6 GHz - 7.2 GHz). In the antenna structure 600 provided by the embodiments of the present application, the S11 of the combined antenna is lower in the operating frequency band, and the matching is optimized compared with the individual antennas.

[0211] In another implementation, the n antenna units may include a first antenna unit and a second antenna unit, where the first antenna unit includes a third patch, and the second antenna unit includes a fourth patch. The third patch is excited with a first resonance mode, and the fourth patch is excited with a second resonance mode. Different antenna units being excited with different resonance modes can form dual resonance or multiple resonances, thereby expanding the operating bandwidth of the antenna.

[0212] Exemplarily, ​ shows a schematic diagram of an antenna structure provided by the embodiments of the present application. As ​ shown, the antenna structure 700 includes antenna unit 1 and antenna unit 2, and antenna unit 1 and antenna unit 2 are patch antennas. Among them, antenna unit 1 includes a third patch, and antenna unit 2 includes a fourth patch. The third patch is excited with a first resonance mode, such as the TM01 mode, and the fourth patch is excited with a second resonance mode, such as the TM10 mode. Here, antenna unit 1 is an example of the first antenna unit, and antenna unit 2 is an example of the second antenna unit. Antenna unit 1 is connected to transmission line 1, and antenna unit 2 is connected to transmission line 2. After transmission line 1 and transmission line 2 are combined, they are electrically connected to the signal line.

[0213] As an example rather than a limitation, the characteristic impedance of transmission line 1 and the characteristic impedance of transmission line 2 are the same, both being Z0 = 100 ohms. The transmission phase difference between transmission line 1 and transmission line 2 is 90°. The characteristic impedance Z3 of the signal line is also 50 ohms, which is half of the characteristic impedance of transmission line or transmission line 2, and the signal line is directly connected to the combining point.

[0214] Taking the third patch and the fourth patch as rectangular patches as an example, ​ shows ​ the Smith chart of the antenna structure shown. According to ​ it can be known that the S11 of the antenna structure 700 is less than -4 dB in the operating frequency band (about 6 GHz - 7 GHz). In addition, the antenna structure 700 can form dual resonance, thereby expanding the operating bandwidth of the antenna.

[0215] To compare the matching results, ​ shows a schematic diagram of the matching results of the individual antennas corresponding to the antenna structure 700 (for example, antenna unit 1 and antenna unit 2 are fed separately). ​(a) and (b) in show the Smith chart of a single antenna and the S-parameter simulation results respectively. According to ​ it can be known that S11 of antenna unit 1 is less than -2 dB in the operating frequency band (about 6 GHz - 7 GHz), and S11 of antenna unit 2 is less than -2 dB in the operating frequency band (about 6 GHz - 7 GHz). In the antenna structure 700 provided by the embodiments of the present application, the S11 of the combined antenna is lower in the operating frequency band, and the matching is optimized compared with the single antenna.

[0216] In some embodiments, when the third patch and the fourth patch are rectangular patches, the first resonance mode and the second resonance mode are the TM01 mode and the TM10 mode respectively, where the excitation position is at a corner of the patch. It can be understood that the contour of the rectangular patch involved in the present application is rectangular, and there may be parts with physical defects thereon, which can increase the layout space for other components.

[0217] Of course, in some other embodiments, the third patch and the fourth patch may also be of other shapes, such as circular, and the corresponding excitation modes also have corresponding names, which will not be introduced one by one here.

[0218] It can be understood that the above embodiments are described by taking the formation of a dual resonance in the antenna structure as an example. In some other embodiments, more than two resonance modes can also be excited to form a multi-resonance antenna, and the present application does not limit this.

[0219] In some embodiments, in the antenna structure provided by the present application, the physical length of each of the n transmission lines is greater than 0. That is, there is a certain length of transmission line connected between each antenna unit and the combining point. Correspondingly, the combining point is not arranged on the radiator of the antenna unit.

[0220] In some other embodiments, the combining point may also be located on the radiator of one of the n antenna units (referred to as the third antenna unit in the present application). Correspondingly, the physical length of the transmission line between the antenna unit where the combining point is located and the combining point is 0, the absolute phase of this transmission line is zero, and the characteristic impedance of this transmission line is equal to the characteristic impedance of the transmission line connected to the fourth antenna unit among the n antenna units, where the fourth antenna unit can be any one of the n antenna units except the third antenna unit.

[0221] Exemplarily, ​ shows a schematic diagram of an antenna structure provided by an embodiment of the present application. ​ The shown antenna structure 800 is different from ​ the shown antenna structure 700 in that in the antenna structure 800, the combining point is located on the radiator of antenna unit 2. Correspondingly, the physical length of transmission line 2 is 0.

[0222] By way of example and not limitation, the characteristic impedance of the transmission line 1 may be Z0 = 100 ohms. The characteristic impedance of the transmission line 2 is considered to be the same as that of the transmission line 1, also 100 ohms. The transmission phase difference between the transmission line 1 and the transmission line 2 is 90°. The characteristic impedance Z3 of the signal line is 50 ohms, which is half of the characteristic impedance of the transmission line 1.

[0223] Still taking the third patch and the fourth patch as rectangular patches as an example, ​ A schematic diagram of the matching result of the antenna structure 800 is shown. ​ In (a) and (b) respectively show the Smith chart and the S-parameter simulation results of the antenna structure 800. According to ​ It can be known that S11 of the antenna structure 800 is less than -4 dB in the operating frequency band (about 6 GHz - 7 GHz).

[0224] In the embodiments of the present application, in the antenna structure 700 and the antenna structure 800, the absolute phases of the transmission lines are different, but the transmission phase differences are the same. According to ​ and ​ It can be known that the matching depth after the combination of the antenna element 1 and the antenna element 2 is not affected by the absolute phase of the transmission line and can reach the expected matching result. In addition, each antenna element is a dual-resonant patch. Correspondingly, the antenna is a 1 / 2 wavelength antenna and does not require grounding.

[0225] Exemplarily, taking n = 3 as an example, ​ A schematic diagram of an antenna structure provided by an embodiment of the present application and a corresponding circuit connection schematic diagram are shown. As ​ shown in (a) of, the antenna structure 900 includes an antenna element 1, an antenna element 2, and an antenna element 3. The antenna element 1 is connected to a transmission line 1, the antenna element 2 is connected to a transmission line 2, and the antenna element 3 is connected to a transmission line 3. The transmission line 1, the transmission line 2, and the transmission line 3 are combined and electrically connected to a signal line 302 at a combining point 301. The antenna structure 900 can be circuit-connected according to the circuit connection schematic diagram shown in (b) of ​

[0226] In this embodiment, the signal line 302 for feeding is connected to the antenna element 1, the antenna element 2, and the antenna element 3 through three transmission lines. The reflection coefficient of the combined antenna is less than that of the individual antennas, so that the matching can be optimized and the system efficiency can be improved.

[0227] ​By way of example and not limitation, the antenna element 1, the antenna element 2, and the antenna element 3 may be patch antennas (e.g., 1 / 4 wavelength patch antennas). The characteristic impedances of the transmission lines 1, 2, and 3 are the same, all being Z0 = 150 ohms. The transmission phase difference between the transmission lines is 60° (i.e., 180° / 3). The characteristic impedance Z3 of the signal line 302 is 50 ohms, which is one-third of the characteristic impedance of the transmission line 1 / transmission line 2 / transmission line 3. The signal line 302 is directly connected to the combining point 301, and the output impedance Z2 of the combining point 301 is also 50 ohms. For convenience, the above relevant parameters are shown in Table 3 below.

[0228] Table 3

[0229]

[0230] ​ Shows ​ The matching result schematic diagram of the antenna structure 900 shown connected according to the circuit shown in (b) in ​ The matching result schematic diagram of the antenna structure 900 shown connected according to the circuit shown in (b) in figure ​ The initial matching result schematic diagram of the antenna structure 900 shown in (a) in figure ​ As shown in (a) in figure ​ The combined matching result schematic diagram of the antenna structure 900 shown in (b) in figure ​ As shown in (b) in figure

[0231] ​ Shows ​ The S-parameter simulation result of the antenna structure 900 shown connected according to the circuit shown in (b) in figure ​ According to what is shown in ​ As shown, for a single antenna (e.g., antenna element 1 or antenna element 2 or antenna element 3), S11 is less than -1 dB in the operating frequency band (about 6 GHz - 7 GHz), and for the combined antenna, S11 is less than -3 dB in the operating frequency band (about 6 GHz - 7 GHz).

[0232] According to ​ And ​ It can be known that the antenna element 1, the antenna element 2, and the antenna element 3 are discrete antennas (i.e., the radiators are discrete). When the reflection coefficient of the antenna element 1 or the antenna element 2 or the antenna element 3 is -X dB, the reflection coefficient of the combined antenna can be increased to -3X dB, thereby optimizing the matching and improving the system efficiency.

[0233] In summary, in the antenna structure provided by the embodiments of the present application, when the characteristic impedances of n transmission lines are equal and the characteristic impedance of the signal line is 1 / n of the characteristic impedance of the transmission line, if the reflection coefficient of a single antenna unit is -X dB, the reflection coefficient of the combined antenna can be increased to -nX dB.

[0234] In the antenna structure provided by the embodiments of the present application, the antenna forms of n antenna units can be completely the same, partially the same, or completely different. Exemplarily, the antenna forms of n antenna units are the same. Here, the antenna form includes the radiator shape (for example, divided into wire antennas, patch antennas, slot antennas, etc.) and / or the radiator size (for example, divided into 1 / 2 wavelength antennas, 1 / 4 wavelength antennas, etc.). For example, the antenna forms of n antenna units are the same, and the specific shapes are the same or similar.

[0235] In some embodiments, in the antenna structure, the absolute phases of n transmission lines form an arithmetic sequence. For example, when n = 2, the absolute phases of the 2 transmission lines can be 0° and 90° respectively; when n = 3, the absolute phases of the 3 transmission lines can be 0°, 60°, and 120° respectively; when n = 4, the absolute phases of the 4 transmission lines can be 0°, 45°, 90°, and 135° respectively; and so on.

[0236] In some embodiments, the transmission phase difference between the k-th transmission line and the (k + 1)-th transmission line among n transmission lines is 180° / n ± 180° / 4n.

[0237] It should be noted that the transmission phase difference involved in the embodiments of the present application is calculated using the absolute phases of the corresponding two transmission lines. Before calculating the phase difference, the absolute phases of the n transmission lines are first taken modulo 180° to obtain the first phase value corresponding to each transmission line, and then the remainders (i.e., the first phase values) corresponding to the n transmission lines are sorted, for example, sorted from small to large or from large to small, and the phase difference between adjacent two transmission lines is calculated according to the order of the arranged transmission lines. For example, taking a group of transmission lines with absolute phases of 0°, 45°, 90°, and 135° and a group of transmission lines with absolute phases of 0°, 45°, 270°, and 135° as an example, taking the absolute phases of the second group of transmission lines modulo 180° gives the absolute phases of the first group of transmission lines. The matching results formed by these two groups of transmission lines are the same. The essential principle of the modulo operation is that due to the periodicity of impedance change, the impedance after the phase changes by 180° is the same as the impedance before the phase change.

[0238] In the embodiments of the present application, there are multiple ways to implement the transmission phase difference. Taking the implementation of the transmission phase difference between the kth transmission line and the k+1th transmission line as an example, for example, the phase difference can be generated by adjusting the length difference between the kth transmission line and the k+1th transmission line; or, the phase difference can be generated by a phase shifting device; or, the phase difference can be generated by a capacitor device and / or an inductor device; or, the phase difference can be generated by a coupling line; or, the phase difference can be generated by adjusting the antenna form of the antenna unit connected to the kth transmission line and the antenna unit connected to the k+1th transmission line; or, the phase difference can be generated by combining at least two of the above methods; and so on. The embodiments of the present application do not limit the implementation method of the phase difference.

[0239] It is understood that the antenna structure provided in the embodiments of the present application can also be referred to as a distributed antenna. Distributed antenna design allows for greater freedom in antenna design, such as antenna form, feeder impedance, and phase, leading to better matching results, thereby improving signal transmission capabilities and enhancing system transmission efficiency and performance.

[0240] In the embodiments of this application, the antenna structure has separate radiators. The form of the radiators and the corresponding feed direction can be designed according to actual needs, and this application does not limit this. Furthermore, the polarization direction and number of polarizations of the antenna structure provided by this application can also be designed according to actual needs, and this application does not limit this. The antenna structure provided by this application is general and has a wide range of applications.

[0241] ​ The figure shows the comparison of the matching results between the antenna structure provided by the embodiment of the present application and the existing structure. ​ Taking the antenna structure 400 shown in FIG. 1 as an example, the phase differences between the transmission line 1 and the transmission line 2 are 180 / n (ie 90°) and 360 / n (ie 180°), respectively. ​ As shown, the matching of 90° phase difference (solid line) is significantly better than the matching of 180° phase difference (dashed line). Moreover, in the present application, the phase difference between the transmission lines is small, so shorter transmission lines can be used.

[0242] ​ A schematic structural block diagram of an electronic device provided in an embodiment of the present application is shown. ​ The electronic device 1000 shown may be ​ A specific example of an electronic device 100 is shown.

[0243] like ​As shown, the electronic device 1000 may include an antenna 1010 and a radio frequency chip 1020. The antenna 1010 is connected to the radio frequency chip 1020. The antenna 1010 is used for transmitting and receiving radio frequency signals, and the radio frequency chip 1020 is used for adjusting radio frequency signals. Specifically, the radio frequency chip 1020 may perform signal conversion (such as converting radio frequency signals into digital signals or converting digital signals into radio frequency signals), power amplification, frequency synthesis, etc. The antenna 1010 may adopt the antenna structures involved in the foregoing embodiments, such as antenna structures 200, 300, 400, 500, 600, 700, 800, 900, etc.

[0244] In some embodiments, the electronic device 1000 may further include an upper layer chip 1030. The upper layer chip 1030 is connected to the radio frequency chip 1020. The upper layer chip 1030 is used for processing radio frequency signals. Exemplarily, the upper layer chip 1030 may be a baseband chip, and the baseband chip may synthesize a baseband signal to be transmitted or decode a received baseband signal.

[0245] In the description of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0246] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present application can easily think of changes or substitutions, which should all be covered by the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An antenna structure, characterized in that, Comprising: n antenna elements, n transmission lines and a signal line, where the n antenna elements are connected to the n transmission lines one by one, and the n transmission lines are combined at a combining point and then connected to the signal line; Among them, the n transmission lines are arranged in the order of the magnitude of the first phase value, the first phase value is the remainder of the absolute phase of the transmission line divided by 180°, and the difference between the first phase value corresponding to the k-th transmission line among the n transmission lines and the first phase value corresponding to the (k + 1)-th transmission line among the n transmission lines is 180° / n ± 180° / 2n, the output impedance of the combining point is less than the characteristic impedance of the transmission line with the smallest characteristic impedance among the n transmission lines, n is greater than or equal to 2, and k is greater than or equal to 1 and less than n.

2. The antenna structure according to claim 1, wherein The n transmission lines are directly connected to the signal line after being combined at the combining point.

3. The antenna structure according to claim 1, characterized in that, The antenna structure further includes: A matching network, which is arranged between the combining point and the signal line.

4. The antenna structure according to claim 2 or 3, characterized in that, The output impedance of the combining point is the characteristic impedance of the signal line.

5. The antenna structure according to claim 4, wherein, The characteristic impedance of the signal line is less than the characteristic impedance of the transmission line with the smallest characteristic impedance among the n transmission lines.

6. The antenna structure according to claim 2 or 3, characterized in that, The antenna structure further includes: An impedance transformer, which is arranged between the combining point and the signal line.

7. The antenna structure according to claim 6, characterized in that, The output impedance of the combining point is the impedance obtained by transforming the characteristic impedance of the signal line through the impedance transformer.

8. The antenna structure according to claim 7, characterized in that, The output impedance of the combining point is less than the characteristic impedance of the signal line.

9. The antenna structure according to claim 8, wherein The characteristic impedance of the signal line is greater than or equal to the characteristic impedance of the transmission line with the smallest characteristic impedance among the n transmission lines.

10. The antenna structure according to claim 8 or 9, characterized in that, The characteristic impedance value of each of the n transmission lines is a first value, the characteristic impedance of the signal line is a third value, and the third value is equal to the first value.

11. The antenna structure according to any one of claims 6 to 10, characterized in that, The impedance transformer is a quarter-wavelength impedance transformer.

12. The antenna structure according to any one of claims 1 to 11, characterized in that, The characteristic impedance of each of the n transmission lines is a first value, the output impedance of the combining point is a second value, and the second value is 1 / n of the first value.

13. The antenna structure according to any one of claims 1 to 12, characterized in that, The first antenna element among the n antenna elements is any one of the following antenna forms: wire antenna, patch antenna or slot antenna.

14. The antenna structure according to claim 13, characterized in that, When the first antenna element is a wire antenna, the radiator of the first antenna element is L-shaped.

15. The antenna structure according to claim 13, wherein When the first antenna element is a patch antenna, the first antenna element includes a first patch and a second patch arranged side by side, the first patch includes a first open end and a first ground end, the second patch includes a second open end and a second ground end, where the second ground end rotates 90° relative to the first ground end, the second open end rotates 90° relative to the first open end, and the rotation directions of the second open end and the second ground end are the same.

16. The antenna structure according to claim 13, wherein When the first antenna element and the second antenna element among the n antenna elements are patch antennas, the first antenna element includes a third patch, the second antenna element includes a fourth patch, the third patch is excited with a first resonance mode, and the fourth patch is excited with a second resonance mode.

17. The antenna structure according to any one of claims 1 to 16, characterized in that, The antenna forms of the n antenna elements are the same.

18. The antenna structure according to any one of claims 1 to 17, characterized in that, The absolute phases of the n transmission lines form an arithmetic progression.

19. The antenna structure according to any one of claims 1 to 18, characterized in that, The combining point is located on the radiator of the third antenna unit among the n antenna units.

20. The antenna structure according to claim 19, wherein, The physical length of the transmission line connected to the third antenna unit is zero, the absolute phase of the transmission line connected to the third antenna unit is zero, and the characteristic impedance of the transmission line connected to the third antenna unit is equal to the characteristic impedance of the transmission line connected to the fourth antenna unit among the n antenna units, where the fourth antenna unit is any one of the n antenna units other than the third antenna unit.

21. The antenna structure according to any one of claims 1 to 20, characterized in that, The difference between the first phase value corresponding to the k-th transmission line and the first phase value corresponding to the (k + 1)-th transmission line is achieved by at least one of the following methods: Generating a phase difference by adjusting the length difference between the k-th transmission line and the (k + 1)-th transmission line; Generating a phase difference by a phase shifter; Generating a phase difference by a capacitor and / or an inductor; Generating a phase difference by a coupled line; or Generating a phase difference by adjusting the antenna forms of the antenna units respectively connected to the k-th transmission line and the (k + 1)-th transmission line.

22. The antenna structure according to any one of claims 1 to 21, characterized in that, The antenna structure is a distributed antenna.

23. An electronic device, characterized in that, It includes the antenna structure according to any one of claims 1 to 22.

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