Antenna structure and electronic device

Abstract

Embodiments of this application provide an antenna structure and an electronic device. A slit is disposed on a ground plane of the antenna structure. Due to the slit, the antenna structure may have at least two different current paths when generating radiation. Correspondingly, the antenna structure may generate at least two different resonances, so that the antenna structure has a good radiation characteristic. The antenna structure includes a first radiator, a second radiator, a ground plane, and a first feed part. A first end of the first radiator and a first end of the second radiator are opposite to each other and are not in contact with each other. A first ground position of the ground plane is coupled to a second end of the first radiator, a second ground position of the ground plane is coupled to a second end of the second radiator, and a first slit extending to the inside of the ground plane is disposed between the first ground position and the second ground position. The first feed part is electrically connected between the ground plane on two sides of the first slit.

Description

[0001] This application claims priorities to Chinese Patent Application No. 202310257395.2, filed with the China National Intellectual Property Administration on March 6, 2023 and entitled "ANTENNA STRUCTURE AND ELECTRONIC DEVICE", and to Chinese Patent Application No. 202310478856.9, filed with the China National Intellectual Property Administration on April 27, 2023 and entitled "ANTENNA STRUCTURE AND ELECTRONIC DEVICE", both of which are incorporated herein by reference in their entireties.TECHNICAL FIELD

[0002] This application relates to the field of wireless communication, and in particular, to an antenna structure and an electronic device.BACKGROUND

[0003] In a current state, frequency bands of a third generation mobile communication technology (3rd generation wireless system, 3G), a fourth generation mobile communication technology (4th generation wireless system, 4G), and a fifth generation mobile communication technology (5th generation wireless system, 5G) coexist as communication frequency bands of an electronic device for a long time, and a quantity of antennas increases.

[0004] An electronic device with a metal appearance is a trend of a current industrial design (industrial design, ID). For the electronic device with the metal appearance, the metal appearance (for example, a side frame or a rear cover) usually needs to be slit, and a part of the metal appearance is used as a radiator of an antenna. However, because a plurality of slits need to be disposed on the metal appearance, integrity of the metal appearance is affected, and an aesthetic appearance is affected. Therefore, structural requirements for miniaturization and fewer slits and performance of a wide frequency band and high efficiency become an important design direction of an antenna in an electronic device.SUMMARY

[0005] Embodiments of this application provide an antenna structure and an electronic device. A slit is disposed on a ground plane of the antenna structure. Due to the slit, the antenna structure may have at least two different current paths when generating radiation. Correspondingly, the antenna structure may generate at least two different resonances, so that the antenna structure has a good radiation characteristic.

[0006] According to a first aspect, an antenna structure is provided, including a first radiator and a second radiator, where a first end of the first radiator and a first end of the second radiator are opposite to each other and are not in contact with each other, and the first end of the first radiator and the first end of the second radiator are open ends; a ground plane, where the ground plane includes a first ground position, a second ground position, and a first slit, a first gap is formed between the ground plane and the first radiator, a second gap is formed between the ground plane and the second radiator, the first ground position is coupled to a second end of the first radiator, the second ground position is coupled to a second end of the second radiator, the first slit extends from an edge of the ground plane to the inside of the ground plane, and at least a part of the first slit is located between the first ground position and the second ground position; and a first feed part, where a first end of the first feed part is coupled to the ground plane on a first side of the first slit, and a second end of the first feed part is coupled to the ground plane on a second side of the first slit.

[0007] According to the technical solution in this embodiment of this application, in the technical solution provided in this embodiment of this application, the ground plane is provided with the first slit between two ground positions of the radiators of the antenna structure. The first feed part and an electronic element are electrically connected between the ground plane on the two sides of the first slit. The antenna structure may generate a first resonance and a second resonance. A frequency of the first resonance is lower than a frequency of the second resonance. An operating bandwidth of the antenna structure may be expanded based on the first resonance and the second resonance.

[0008] With reference to the first aspect, in some implementations of the first aspect, the antenna structure further includes an electronic element. The first end of the first feed part is coupled to the ground plane on the first side of the first slit via a first end of the electronic element, and a second end of the electronic element is coupled to the ground plane on the second side of the first slit.

[0009] According to the technical solution in this embodiment of this application, when the first feed part feeds an electrical signal, there may be two different current paths due to a current selection characteristic (high-pass characteristic) of the electronic element.

[0010] With reference to the first aspect, in some implementations of the first aspect, the electronic element includes a capacitor, and an equivalent capacitance value of the electronic element may be greater than or equal to 0.3 pF and less than or equal to 3 pF.

[0011] According to the technical solution in this embodiment of this application, a capacitance value (or the equivalent capacitance value) of the electronic element may be determined based on an operating frequency band of the antenna structure. In an embodiment, the operating frequency band of the antenna structure includes at least a part of a low frequency band (698 MHz to 960 MHz), and the capacitance value (or the equivalent capacitance value) of the electronic element may be greater than or equal to 0.3 pF and less than or equal to 3 pF. In an embodiment, the operating frequency band of the antenna structure includes at least a part of a middle frequency band (1710 MHz to 2170 MHz) or a high frequency band (2300 MHz to 2690 MHz), and the capacitance value (or the equivalent capacitance value) of the electronic element is greater than or equal to 0.3 pF and less than or equal to 2 pF.

[0012] With reference to the first aspect, in some implementations of the first aspect, a physical length of the first slit between the edge of the ground plane and a position at which the first feed part is electrically connected to the ground plane is less than half of a physical length L1 of the first slit.

[0013] With reference to the first aspect, in some implementations of the first aspect, the antenna structure is configured to generate the first resonance and a second resonance, and a frequency of the first resonance is lower than a frequency of the second resonance. At a resonance point of the first resonance, currents on edges of the ground plane on the two sides of the first slit are the same in direction; and at a resonance point of the second resonance, currents on the edges of the ground plane on the two sides of the first slit are the same in direction.

[0014] According to the technical solution in this embodiment of this application, the first slit disposed on the ground plane has little impact on current distribution and electric field distribution on the first radiator and the second radiator. At the resonance point of the first resonance and the resonance point of the second resonance, the currents on the edges of the ground plane on the two sides of the first slit are the same in direction. Because the current distribution and the electric field distribution on the first radiator and the second radiator do not change, characteristics of the CM mode in the foregoing embodiment are maintained in both a first mode in which the first resonance is generated and a second mode in which the second resonance is generated.

[0015] Because both the first mode and the second mode are CM modes, a maximum radiation direction of a pattern corresponding to the first resonance is approximately the same as a maximum radiation direction of a pattern corresponding to the second resonance, and no pattern change occurs. This facilitates application to a MIMO antenna system.

[0016] In addition, because both the first mode and the second mode are CM modes, no efficiency dip is generated in an operating frequency band formed by the first resonance and the second resonance, so that the antenna structure can have good radiation efficiency and system efficiency.

[0017] With reference to the first aspect, in some implementations of the first aspect, at a resonance point of a first resonance, a current between the first ground position and the second ground position flows through an edge of the ground plane between the first ground position and the second ground position and the ground plane on the two sides of the first slit; and at a resonance point of a second resonance, a current between the first ground position and the second ground position flows through the edge of the ground plane between the first ground position and the second ground position and the electronic element.

[0018] With reference to the first aspect, in some implementations of the first aspect, an electrical length of the first slit falls within a range (a quarter of a first wavelength±10%), and the first wavelength is a wavelength corresponding to a first resonance. In an embodiment, the first wavelength is a dielectric wavelength corresponding to the first resonance.

[0019] According to the technical solution in this embodiment of this application, when the electrical length of the first slit is approximately the quarter of the first wavelength, and in a resonant frequency band of the first resonance, a current is transmitted from the first side of the first slit (a second position) to the second side through the ground plane around the first slit, an electrical length of a current path is approximately half of the first wavelength. After the current passes through the path with the electrical length of the half wavelength, a phase change is 360°, so that currents on the ground plane on two sides of the second position are the same in direction.

[0020] With reference to the first aspect, in some implementations of the first aspect, a sum of an electrical length of the first radiator and an electrical length of the second radiator falls within a range (half of the first wavelength±10%), and the first wavelength is the wavelength corresponding to the first resonance. In an embodiment, the first wavelength is the dielectric wavelength corresponding to the first resonance.

[0021] With reference to the first aspect, in some implementations of the first aspect, the first slit is in a straight line shape, a fold line shape, an arc shape, or a T shape.

[0022] According to the technical solution in this embodiment of this application, the first slit may alternatively be in a straight line shape, a fold line shape, an arc shape, a T shape, or the like. This is not limited in embodiments of this application. It should be understood that, when the first slit is in the foregoing different shapes, the physical length of the first slit may be understood as a sum of physical lengths of parts of the first slit that extend in different directions.

[0023] With reference to the first aspect, in some implementations of the first aspect, the physical length L1 of the first slit, a physical length L2 of the first radiator, and a physical length L3 of the second radiator satisfy: (L2+L3)×25%≤L1≤(L2+L3)×100%.

[0024] With reference to the first aspect, in some implementations of the first aspect, the physical length L2 of the first radiator and the physical length L3 of the second radiator satisfy: L2×70%≤L3≤L2×130%.

[0025] According to the technical solution in this embodiment of this application, the physical length of the first radiator and the physical length of the second radiator need to be approximately the same, so that a difference between a frequency of the resonance point of the second resonance and a frequency of the resonance point of the first resonance falls within a threshold, and the first resonance and the second resonance may jointly form the operating frequency band, to expand the operating bandwidth of the antenna structure. In an embodiment, the electrical length of the first radiator and the electrical length of the second radiator need to be approximately the same.

[0026] With reference to the first aspect, in some implementations of the first aspect, the antenna structure further includes a third radiator and a second feed part, and the second feed part is different from the first feed part. A first end of the third radiator and a second end of the third radiator are open ends. A central area of the third radiator includes a feed point, and the second feed part is coupled to the feed point.

[0027] According to the technical solution in this embodiment of this application, in the antenna structure, the first radiator, the second radiator, and the first feed part may form a first antenna element, and the first antenna element may operate in a CM mode of a slot antenna. The third radiator and the second feed part may form a second antenna element, and the second antenna element may operate in a CM mode of a wire antenna. Because electric fields generated by the first antenna element and the second antenna element are orthogonal ((integrally orthogonal) an inner product of the electric fields in a far field is zero), there is good isolation between the first antenna element and the second antenna element. In an embodiment, an operating frequency band of the first antenna element and an operating frequency band of the second antenna element include a same communication frequency band, and may be applied to a MIMO antenna system in an electronic device.

[0028] With reference to the first aspect, in some implementations of the first aspect, a distance between the third radiator and the first radiator or the second radiator is less than or equal to 10 mm.

[0029] According to the technical solution in this embodiment of this application, a distance between the third radiator and the first radiator or the second radiator is less than or equal to 10 mm, so that the radiators of the antenna structure are compactly arranged and occupy small space.

[0030] With reference to the first aspect, in some implementations of the first aspect, a length L4 of the third radiator in a first direction and a distance L5 between the first ground position and the second ground position in the first direction satisfy: L4×90%≤L5≤L4×110%, and the first direction is an extension direction of a length of the first radiator.

[0031] According to the technical solution in this embodiment of this application, when the length of the third radiator in the first direction is approximately the same as a length of an area in which the first radiator and the second radiator are located in the first direction, the radiators of the antenna structure occupy smallest space, and are more convenient to be disposed in an electronic device with compact space.

[0032] With reference to the first aspect, in some implementations of the first aspect, a frequency of an electrical signal fed by the first feed part is the same as a frequency of an electrical signal fed by a second feed part.

[0033] According to the technical solution in this embodiment of this application, the operating frequency band of the first antenna element and the operating frequency band of the second antenna element include the same communication frequency band, and may be applied to the MIMO antenna system in the electronic device.

[0034] According to a second aspect, an electronic device is provided, including the antenna structure according to any one of the implementations of the first aspect. The electronic device further includes a side frame and a PCB, and the side frame includes a conductive part. The side frame has a first position, a second position, and a second slit, and the second slit is located between the first position and the second position. The first radiator of the antenna structure includes at least a part of the side frame between the first position and the second slit, and the second radiator of the antenna structure includes at least a part of the side frame between the second slit and the second position. The PCB includes the ground plane of the antenna structure.

[0035] With reference to the second aspect, in some implementations of the second aspect, the electronic device further includes a bracket, and at least a part of the third radiator of the antenna structure is located on a surface of the bracket.

[0036] With reference to the second aspect, in some implementations of the second aspect, the electronic device further includes a rear cover, and at least a part of the third radiator of the antenna structure is located on a surface of the rear cover.

[0037] With reference to the second aspect, in some implementations of the second aspect, a distance between the ground plane and a projection of the first radiator on a plane on which the ground plane is located or a projection of the second radiator on a plane on which the ground plane is located is less than 1 mm.

[0038] With reference to the second aspect, in some implementations of the second aspect, the first radiator and the second radiator are configured to generate a first resonance and a second resonance, where a resonant frequency band formed by the first resonance and the second resonance includes a first frequency band; the third radiator is configured to generate a third resonance, where a resonant frequency band formed by the third resonance includes the first frequency band; and an operating frequency band of the electronic device includes the first frequency band.BRIEF DESCRIPTION OF DRAWINGS

[0039] FIG. 1 is a diagram of an electronic device according to an embodiment of this application; FIG. 2 is a diagram of current distribution corresponding to an HWM of a dipole antenna according to this application; FIG. 3 is a diagram of current distribution corresponding to an OWM of a dipole antenna according to this application; FIG. 4 is a diagram of current distribution of a bent dipole antenna according to an embodiment of this application; FIG. 5 is a diagram of current distribution of a bent dipole antenna according to an embodiment of this application; FIG. 6 is a diagram of a common-mode structure of a slot antenna and distribution of corresponding currents, electric fields, and magnetic currents according to this application; FIG. 7 is a diagram of a differential-mode structure of a slot antenna and distribution of corresponding currents, electric fields, and magnetic currents according to this application; FIG. 8 shows a pattern generated by the slot antenna shown in FIG. 6 in a CM mode; FIG. 9 shows a pattern generated by the slot antenna shown in FIG. 7 in a DM mode; FIG. 10 is a diagram of an antenna structure 200 according to an embodiment of this application; FIG. 11 is a diagram of an antenna structure 300 according to an embodiment of this application; FIG. 12 is a diagram of S-parameter simulation results of the antenna structures shown in FIG. 10 and FIG. 11; FIG. 13 is a Smith chart of the antenna structures shown in FIG. 10 and FIG. 11; FIG. 14 is a diagram of simulation results of system efficiency of the antenna structures shown in FIG. 10 and FIG. 11; FIG. 15 is a diagram of current distribution of the antenna structure 200 shown in FIG. 10 at a first resonance (for example, 1.6 GHz); FIG. 16 is a diagram of current distribution of the antenna structure 200 shown in FIG. 10 at a second resonance (for example, 1.9 GHz); FIG. 17 is a diagram of electric field distribution of the antenna structure 200 shown in FIG. 10 at a first resonance (for example, 1.6 GHz); FIG. 18 is a diagram of electric field distribution of the antenna structure 200 shown in FIG. 10 at a second resonance (for example, 1.9 GHz); FIG. 19 shows a pattern of the antenna structure 200 shown in FIG. 10 at a first resonance (for example, 1.6 GHz); FIG. 20 shows a pattern of the antenna structure 200 shown in FIG. 10 at a second resonance (for example, 1.9 GHz); FIG. 21 is a diagram of another antenna structure 200 according to an embodiment of this application; FIG. 22 is a diagram of another antenna structure 200 according to an embodiment of this application; FIG. 23 is a diagram of another antenna structure 200 according to an embodiment of this application; FIG. 24 is a diagram of S-parameter simulation results of the antenna structures shown in FIG. 10 and FIG. 21 to FIG. 23; FIG. 25 is a Smith chart of the antenna structures shown in FIG. 10 and FIG. 21 to FIG. 23; FIG. 26 is a diagram of simulation results of system efficiency of the antenna structures shown in FIG. 10 and FIG. 21 to FIG. 23; FIG. 27 is a diagram of simulation results of radiation efficiency of the antenna structures shown in FIG. 10 and FIG. 21 to FIG. 23; FIG. 28 is a diagram of an electronic device 10 according to an embodiment of this application; FIG. 29 is a diagram of another antenna structure 200 according to an embodiment of this application; FIG. 30 is a diagram of a layout of the antenna structure 200 shown in FIG. 29; FIG. 31 is a diagram of a layout of the antenna structure 200 shown in FIG. 29; FIG. 32 is a diagram of an S-parameter simulation result of the antenna structure shown in FIG. 30; FIG. 33 is a diagram of an S-parameter simulation result of the antenna structure shown in FIG. 31; FIG. 34 is a diagram of a simulation result of system efficiency of the antenna structure shown in FIG. 30; and FIG. 35 is a diagram of a simulation result of system efficiency of the antenna structure shown in FIG. 31. DESCRIPTION OF EMBODIMENTS

[0040] The following explains terms that may appear in embodiments of this application.

[0041] It should be understood that the term "and / or" in this specification describes only a same field for describing associated objects and represents that three relationships may exist. For example, A and / or B may represent the following three cases: Only A exists, both A and B exist, and only B exists. In addition, the character " / " in this specification generally indicates an "or" relationship between the associated objects.

[0042] In this application, "within a range of ..." is used, except when it is separately specified that no end value is included, end values at both ends of the range are included by default. For example, within a range from 1 to 5, two values 1 and 5 are included.

[0043] Coupling: The coupling may be understood as direct coupling and / or indirect coupling, and a "coupling connection" may be understood as a direct coupling connection and / or an indirect coupling connection. The direct coupling may also be referred to as an "electrical connection", and may be understood as physical contact and electrical conduction of components; or may be understood as a form in which different components in a line structure are connected through a physical line that may transmit an electrical signal, for example, a copper foil or a conductive wire of a printed circuit board (printed circuit board, PCB). The "indirect coupling" may be understood as electrical conduction of two conductors through air or without contact. In an embodiment, the indirect coupling may also be referred to as capacitive coupling. For example, signal transmission is implemented by forming an equivalent capacitor through coupling in a gap between two spaced conductive members.

[0044] Lumped element / component: The lumped element / component is a general name of all elements whose sizes are far less than a wavelength corresponding to an operating frequency of a circuit. For a signal, a characteristic of the element is always constant at any time, regardless of a frequency.

[0045] Distributed element / component: A difference between the distributed element and the lumped element lies in that if a size of an element is close to or greater than a wavelength corresponding to an operating frequency of a circuit, a characteristic of each point of the element varies with a signal when the signal passes through the element. In this case, the element cannot be considered as a single entity with a constant characteristic, but needs to be referred to as a distributed element.

[0046] Capacitor: The capacitor may be understood as a lumped capacitor and / or a distributed capacitor. The lumped capacitor is a capacitive component, for example, a capacitive element. The distributed capacitor (or a distributed type capacitor) is an equivalent capacitor formed by two conductive members that are spaced by a specific gap.

[0047] Inductor: The inductor may be understood as a lumped inductor and / or a distributed inductor. The lumped inductor is an inductive component, for example, an inductive element. The distributed inductor (or distributed type inductor) is an equivalent inductor formed by a conductive member with a specific length.

[0048] Radiator: The radiator is an apparatus configured to receive / send electromagnetic wave radiation in an antenna. In some cases, an "antenna" is a radiator in a narrow sense. The radiator converts guided wave energy from a transmitter into a radio wave, or converts a radio wave into guided wave energy to radiate and receive a radio wave. Modulated high-frequency current energy (or guided wave energy) generated by the transmitter is transmitted to a transmit radiator through a feeder. The radiator converts the energy into specific polarized electromagnetic wave energy and radiates the energy in a required direction. A receive radiator converts specific polarized electromagnetic wave energy from a specific direction of space into modulated high-frequency current energy, and transmits the modulated high-frequency current energy to an input end of a receiver through a feeder.

[0049] The radiator may include a conductor having a specific shape and size, for example, a linear radiator or a sheet-like radiator. A specific shape is not limited in this application. In an embodiment, the linear radiator may be referred to as a wire antenna for short. In an embodiment, the linear radiator may be implemented by a conductive side frame, and may also be referred to as a side frame antenna. In an embodiment, the linear radiator may be implemented by a bracketed conductor, and may also be referred to as a bracketed antenna. In an embodiment, a wire diameter (for example, including a thickness and a width) of the linear radiator or a radiator of the wire antenna is far less than a wavelength (for example, a dielectric wavelength) (for example, is less than 1 / 16 of the wavelength), and a length may be compared with the wavelength (for example, the dielectric wavelength) (for example, the length is approximately 1 / 8 of the wavelength, or 1 / 8 to 1 / 4 of the wavelength, or 1 / 4 to 1 / 2 of the wavelength, or greater). Main forms of the wire antenna include a dipole antenna, a half-wave dipole antenna, a monopole antenna, a loop antenna, an inverted F antenna (inverted F antenna, IFA), and a planar inverted F antenna (planar inverted F antenna, PIFA). For example, for the dipole antenna, each dipole antenna usually includes two radiation stubs, and each stub is fed by a feed part from a feed end of the radiation stub. For example, the IFA may be considered as being obtained by adding a ground path to a monopole antenna. The IFA has one feed point and one ground point, and is referred to as the inverted F antenna because a side view of the IFA is in an inverted F shape. In an embodiment, the sheet-like radiator may include a microstrip antenna or a patch (patch) antenna. In an embodiment, the sheet-like radiator may be implemented by a planar conductor (for example, a conductive sheet or a conductive coating). In an embodiment, the sheet-like radiator may include a conductive sheet, for example, a copper sheet. In an embodiment, the sheet-like radiator may include a conductive coating, for example, silver paste. The sheet-like radiator is in a shape of a circle, a rectangle, a loop, or the like. A specific shape is not limited in this application. A structure of the microstrip antenna generally includes a dielectric substrate, a radiator, and a ground plane, where the dielectric substrate is disposed between the radiator and the ground plane.

[0050] The radiator may also include a slot or a slit formed on the conductor, for example, a closed or semi-closed slot or slit formed on a grounded conductor surface. In an embodiment, a radiator with a slot or slit may be referred to as a slot antenna or a slotted antenna for short. In an embodiment, a radiator with a closed slot or slit may be referred to as a closed slot antenna for short. In an embodiment, a radiator with a semi-closed slot or slit (for example, an opening is additionally provided on the closed slot or slit) may be referred to as an open slot antenna for short. In some embodiments, the slit is long strip-shaped. In some embodiments, a length of the slit is approximately half the wavelength (for example, the dielectric wavelength). In some embodiments, a length of the slit is approximately an integer multiple of the wavelength (for example, one time of the dielectric wavelength). In some embodiments, the slit may be used for feeding through a transmission line bridged on one side or two sides of the slot. In this way, a radio frequency electromagnetic field is excited on the slit, and an electromagnetic wave is radiated to space. In an embodiment, a radiator of the slot antenna or the slotted antenna may be implemented by a conductive side frame that is grounded at two ends, and may also be referred to as a side frame antenna. In this embodiment, it may be considered that the slot antenna or the slotted antenna includes a linear radiator, and the linear radiator is spaced apart from the ground plane and is grounded at two ends of the radiator, to form a closed or semi-closed slot or slit. In an embodiment, the radiator of the slot antenna or the slotted antenna may be implemented by a bracketed conductor that is grounded at both ends, and may also be referred to as a bracketed antenna.

[0051] A feed unit (feed part) / feed circuit / feed structure is a combination of all components of an antenna for receiving and transmitting radio frequency waves. In a case of a receive antenna, the feed unit may be considered as an antenna part from a first amplifier to a front-end transmitter. In a transmit antenna, the feed unit may be considered as a part after a last power amplifier. In some cases, the "feed unit" is understood in a narrow sense as a radio frequency chip, or includes a transmission path from the radio frequency chip to a radiator or a feed point on a transmission line. The feed unit has a function of converting a radio wave into an electrical signal and sending the electrical signal to a receiver component. Usually, the feed circuit is considered as a part of the antenna, and is configured to convert a radio wave into an electrical signal, and vice versa. When the antenna is designed, maximum power transmission possibility and efficiency need to be considered. Therefore, a feed impedance of the antenna shall match a load resistance. The feed impedance of the antenna is a combination of a resistance, a capacitance, and an inductance. To ensure a maximum power transmission condition, two impedances (the load resistance and the feed impedance) need to match. The matching can be completed by considering a frequency requirement and a design parameter (for example, a gain, directivity, and radiation efficiency) of the antenna.

[0052] End / point: The "end / point" in a first end / second end / feed end / ground end / feed point / ground point / connection point of an antenna radiator cannot be understood in a narrow sense as an endpoint or an end part that is physically disconnected from another radiator, and may also be considered as a point or a segment on a continuous radiator. In an embodiment, the "end / point" may include a connection / coupling area that is on the antenna radiator and that is coupled to another conductive structure. For example, the feed end / feed point may be a coupling area (for example, an area opposite to a part of the feed circuit) that is on the antenna radiator and that is coupled to the feed structure or the feed circuit. For another example, the ground end / ground point may be a connection / coupling area that is on the antenna radiator and that is coupled to a ground structure or a ground circuit.

[0053] Open end and closed end: In some embodiments, the open end / ground end is, for example, relative to whether the end is grounded. The closed end is grounded, and the open end is not grounded. In some embodiments, the open end / closed end is, for example, relative to another conductor. The closed end is electrically connected to the another conductor, and the open end is not electrically connected to the another conductor. In an embodiment, the open end may also be referred to as a free end, an opening end, or an open-circuit end. In an embodiment, the closed end may also be referred to as a ground end or a short-circuit end. It should be understood that, in some embodiments, another conductor may be coupled through the open end, to transfer coupling energy (which may be understood as transferring a current).

[0054] Resonance / resonance frequency: The resonance frequency is also referred to as a resonant frequency. The resonance frequency may be a frequency at which an imaginary part of an input impedance of an antenna is zero. The resonance frequency may have a frequency range, namely, a frequency range in which a resonance occurs. A frequency corresponding to a strongest resonance point is a center frequency. A return loss of the center frequency may be less than -20 dB. It should be understood that, unless otherwise specified, in "generating a first resonance" by the antenna / radiator mentioned in this application, the first resonance is a fundamental mode resonance generated by the antenna / radiator, or a resonance with a lowest frequency generated by the antenna / radiator.

[0055] Resonant frequency band / communication frequency band / operating frequency band: Regardless of a type of antenna, the antenna always operates within a specific frequency range (a frequency band width). For example, an operating frequency band of an antenna supporting a B40 frequency band includes a frequency within a range of 2300 MHz to 2400 MHz. In other words, the operating frequency band of the antenna includes the B40 frequency band. A frequency range that meets a requirement of an indicator may be considered as an operating frequency band of the antenna.

[0056] Electrical length: The electrical length may be a ratio of a physical length (namely, a mechanical length or a geometric length) to a wavelength of a transmitted electromagnetic wave, and the electrical length may satisfy the following formula: L ¯ = L λ .

[0057] L is the physical length, and λ is the wavelength of the electromagnetic wave.

[0058] Wavelength: The wavelength or an operating wavelength may be a wavelength corresponding to a center frequency of a resonance frequency or a center frequency of an operating frequency band supported by an antenna. For example, it is assumed that a center frequency of a B1 uplink frequency band (with a resonance frequency ranging from 1920 MHz to 1980 MHz) is 1955 MHz. The operating wavelength may be a wavelength calculated based on the frequency of 1955 MHz. The "operating wavelength" is not limited to the center frequency, and may alternatively be a wavelength corresponding to a non-center frequency of the resonance frequency or the operating frequency band.

[0059] It should be understood that a wavelength of a radiation signal in the air may be calculated as follows: (air wavelength or vacuum wavelength)=speed of light / frequency, where the frequency is a frequency (MHz) of the radiation signal, and the speed of light may be 3×108 m / s. A wavelength of the radiation signal in a medium may be calculated as follows: dielectric wavelength = speed of light / ε / frequency ,, where ε is a relative dielectric constant of the medium. The wavelength in embodiments of this application is usually a dielectric wavelength, and may be a dielectric wavelength corresponding to the center frequency of the resonance frequency, or a dielectric wavelength corresponding to the center frequency of the operating frequency band supported by the antenna. For example, it is assumed that the center frequency of the B1 uplink frequency band (with the resonance frequency ranging from 1920 MHz to 1980 MHz) is 1955 MHz. The wavelength may be a dielectric wavelength calculated based on the frequency of 1955 MHz. The "dielectric wavelength" is not limited to the center frequency, and may alternatively be a dielectric wavelength corresponding to the non-center frequency of the resonance frequency or the operating frequency band. For ease of understanding, the dielectric wavelength mentioned in embodiments of this application may be simply calculated based on a relative dielectric constant of the medium filled on one or more sides of the radiator.

[0060] Antenna system efficiency (total efficiency) of an antenna: The total efficiency of the antenna is a ratio of input power to output power at an antenna port.

[0061] Radiation efficiency (radiation efficiency) of an antenna: The radiation efficiency of the antenna is a ratio of power radiated by the antenna to space (namely, power that is effectively converted into an electromagnetic wave) to active power input to the antenna. Herein, active power input to the antenna=input power of the antenna-loss power. The loss power mainly includes return loss power and metal ohmic loss power and / or dielectric loss power. The radiation efficiency is a value for measuring a radiation capability of the antenna. Both a metal loss and a dielectric loss are factors that affect the radiation efficiency.

[0062] A person skilled in the art may understand that the efficiency is usually indicated by a percentage, and there is a corresponding conversion relationship between the efficiency and dB. Efficiency closer to 0 dB indicates better antenna efficiency.

[0063] Antenna pattern: The antenna pattern is also referred to as a radiation pattern, is a pattern in which relative field strength (a normalized modulus value) of a radiation field of an antenna changes with a direction at a specific distance from the antenna (a far field), and is usually represented by two plane patterns that are perpendicular to each other in a maximum radiation direction of the antenna.

[0064] The antenna pattern usually includes a plurality of radiation beams. A radiation beam with highest radiation intensity is referred to as a main lobe, and the other radiation beams are referred to as minor lobes or side lobes. In the minor lobes, a minor lobe in an opposite direction of the main lobe is also referred to as a back lobe.

[0065] Smith (Smith) chart: The Smith chart is a calculation chart with equivalent circles for normalized input impedance (or admittance) plotted on a reflection coefficient plane. The chart includes three circles for solving a problem with a transmission line and some waveguide problems by using a graphical method, to avoid a complex operation.

[0066] Antenna return loss: The antenna return loss may be understood as a ratio of power of a signal reflected back to an antenna port through an antenna circuit to transmit power of the antenna port. A smaller reflected signal indicates a larger signal radiated by an antenna to space and higher radiation efficiency of the antenna. A larger reflected signal indicates a smaller signal radiated by the antenna to space and lower radiation efficiency of the antenna.

[0067] The antenna return loss may be represented by an S11 parameter, and S11 is one of S parameters. S11 indicates a reflection coefficient, and the parameter can represent transmit efficiency of the antenna. The S11 parameter is usually a negative number. A smaller S11 parameter indicates a smaller antenna return loss, less energy reflected back by the antenna, namely, more energy that actually enters the antenna, and higher system efficiency of the antenna. A larger S11 parameter indicates a larger antenna return loss and lower system efficiency of the antenna.

[0068] It should be noted that, -6 dB is usually used as a standard value of S11 in engineering. When the value of S11 of the antenna is less than -6 dB, it may be considered that the antenna can operate normally, or it may be considered that transmit efficiency of the antenna is good.

[0069] Ground (Ground plane) (ground, GND): The ground (ground plane) may generally be at least a part of any grounding plane, grounding plate, ground metal layer, or the like in an electronic device (like a mobile phone), or at least a part of any combination of the foregoing grounding plane, grounding plate, ground component, or the like. The "ground" may be configured to ground components in the electronic device. In an embodiment, the "ground" may be a grounding plane of a circuit board of the electronic device, or may be a grounding plate formed by a middle frame of the electronic device or a ground metal layer formed by a metal film below a screen of the electronic device. In an embodiment, the circuit board may be a printed circuit board (printed circuit board, PCB), for example, an 8-layer board, a 10-layer board, a 12-layer board, a 13-layer board, or a 14-layer board having 8, 10, 12, 13, or 14 layers of conductive materials respectively, or an element that is separated and electrically insulated by a dielectric layer or an insulation layer like a glass fiber or a polymer. In an embodiment, the circuit board includes a dielectric substrate, a grounding plane, and a trace layer. The trace layer and the grounding plane are electrically connected through a via. In an embodiment, components such as a display, a touchscreen, an input button, a transmitter, a processor, a memory, a battery, a charging circuit, and a system on chip (system on chip, SoC) structure may be mounted on or connected to the circuit board, or electrically connected to the trace layer and / or the grounding plane in the circuit board. For example, a radio frequency source is disposed on the trace layer.

[0070] Any of the foregoing grounding plane, or grounding plate, or ground metal layer is made of a conductive material. In an embodiment, the conductive material may be any one of the following materials: copper, aluminum, stainless steel, brass and an alloy thereof, copper foil on an insulation substrate, aluminum foil on the insulation substrate, gold foil on the insulation substrate, silver-plated copper, silver-plated copper foil on the insulation substrate, silver foil on the insulation substrate, tin-plated copper, cloth impregnated with graphite powder, a graphite-coated substrate, a copper-plated substrate, a brass-plated substrate, and an aluminum-plated substrate. A person skilled in the art may understand that the grounding plane / grounding plate / ground metal layer may alternatively be made of another conductive material.

[0071] Grounding: The grounding is coupling with the ground / ground plane in any manner. In an embodiment, the grounding may be grounding via an entity, for example, grounding via an entity (or referred to as entity grounding) at a specific position on a side frame is implemented via some mechanical parts of a middle frame. In an embodiment, the grounding may be grounding via a component, for example, grounding via a component (or referred to as component grounding) like a capacitor / inductor / resistor connected in series or in parallel.

[0072] The following describes technical solutions of embodiments of this application with reference to accompanying drawings.

[0073] As shown in FIG. 1, an electronic device 10 may include a cover (cover) 13, a display / module (display) 15, a printed circuit board (printed circuit board, PCB) 17, a middle frame (middle frame) 19, and a rear cover (rear cover) 21. It should be understood that, in some embodiments, the cover 13 may be cover glass (cover glass), or may be replaced with a cover made of another material, for example, a cover made of a polyethylene terephthalate (Polyethylene terephthalate, PET) material.

[0074] The cover 13 may be tightly attached to the display module 15, and may be mainly configured to protect the display module 15 for dust resistance.

[0075] In an embodiment, the display module 15 may include a liquid crystal display (liquid crystal display, LCD) panel, a light-emitting diode (light-emitting diode, LED) display panel, an organic light-emitting semiconductor (organic light-emitting diode, OLED) display panel, or the like. This is not limited in embodiments of this application.

[0076] The middle frame 19 is mainly used to support the entire electronic device. FIG. 1 shows that the PCB 17 is disposed between the middle frame 19 and the rear cover 21. It should be understood that, in an embodiment, the PCB 17 may alternatively be disposed between the middle frame 19 and the display module 15. This is not limited in embodiments of this application. The printed circuit board PCB 17 may be a flame-resistant material (FR-4) dielectric board, or may be a Rogers (Rogers) dielectric board, or may be a hybrid dielectric board of Rogers and FR-4, or the like. Herein, FR-4 is a grade designation of a flame-resistant material, and the Rogers dielectric board is a high-frequency board. An electronic element, for example, a radio frequency chip, is carried on the PCB 17. In an embodiment, a metal layer may be disposed on the printed circuit board PCB 17. The metal layer may be configured to ground the electronic element carried on the printed circuit board PCB 17, or may be configured to ground another element, for example, a bracketed antenna or a side frame antenna. The metal layer may be referred to as a ground plane, a grounding plate, or a grounding plane. In an embodiment, the metal layer may be formed by etching metal on a surface of any dielectric board in the PCB 17. In an embodiment, the metal layer configured for grounding may be disposed on a side that is of the printed circuit board PCB 17 that is close to the middle frame 19. In an embodiment, an edge of the printed circuit board PCB 17 may be considered as an edge of the grounding plane of the PCB 17. In an embodiment, the metal middle frame 19 may also be configured to ground the foregoing element. The electronic device 10 may further have another ground plane / grounding plate / grounding plane. As described above, details are not described herein again.

[0077] The electronic device 10 may further include a battery (not shown in the figure). The battery may be disposed between the middle frame 19 and the rear cover 21, or may be disposed between the middle frame 19 and the display module 15. This is not limited in embodiments of this application. In some embodiments, the PCB 17 is divided into a mainboard and a sub-board. The battery may be disposed between the mainboard and the sub-board. The mainboard may be disposed between the middle frame 19 and an upper edge of the battery, and the sub-board may be disposed between the middle frame 19 and a lower edge of the battery.

[0078] The electronic device 10 may further include a side frame 11. The side frame 11 may be made of a conductive material like metal. The side frame 11 may be disposed between the display module 15 and the rear cover 21, and circumferentially extends around a periphery of the electronic device 10. The side frame 11 may have four sides surrounding the display module 15, to help fasten the display module 15. In an implementation, the side frame 11 made of a metal material may be directly used as a metal side frame of the electronic device 10 to form an appearance of the metal side frame, and is applicable to a metal industrial design (industrial design, ID). In another implementation, an outer surface of the side frame 11 may alternatively be made of a non-metal material, for example, a plastic side frame, to form an appearance of a non-metal side frame, and is applicable to a non-metal ID.

[0079] The middle frame 19 may include the side frame 11, and the middle frame 19 including the side frame 11 is used as an integrated part, and may support an electronic component in the entire device. The cover 13 and the rear cover 21 are respectively closed along an upper edge and a lower edge of the side frame, to form a casing or a housing (housing) of the electronic device. In an embodiment, the cover 13, the rear cover 21, the side frame 11, and / or the middle frame 19 may be collectively referred to as a casing or a housing of the electronic device 10. It should be understood that the "casing or housing" may mean a part or all of any one of the cover 13, the rear cover 21, the side frame 11, and the middle frame 19, or mean a part or all of any combination of the cover 13, the rear cover 21, the side frame 11, and the middle frame 19.

[0080] At least a part of the side frame 11 on the middle frame 19 may serve as a radiator of an antenna to transmit / receive a radio frequency signal. A gap may exist between the part of the side frame that serves as the radiator and another part of the middle frame 19, to ensure that the radiator of the antenna has a good radiation environment. In an embodiment, the middle frame 19 may be provided with an aperture at the part of the side frame that serves as the radiator, to facilitate radiation of the antenna.

[0081] Alternatively, the side frame 11 may not be considered as a part of the middle frame 19. In an embodiment, the side frame 11 may be connected to and integrally formed with the middle frame 19. In another embodiment, the side frame 11 may include a protruding part extending inward, to be connected to the middle frame 19, for example, connected via a spring or a screw, or connected through welding. The protruding part of the side frame 11 may be further configured to receive a feed signal, so that at least a part of the side frame 11 serves as a radiator of an antenna to receive / transmit a radio frequency signal. A gap 42 may exist between the middle frame 30 and the part of the side frame that serves as the radiator, to ensure that the radiator of the antenna has a good radiation environment, and the antenna has a good signal transmission function.

[0082] The rear cover 21 may be a rear cover made of a metal material, or may be a rear cover made of a non-conductive material, for example, may be a non-metal rear cover like a glass rear cover and a plastic rear cover, or may be a rear cover made of both a conductive material and a non-conductive material. In an embodiment, the rear cover 21 including the conductive material may replace the middle frame 19, and serves as an integrated part with the side frame 11, to support an electronic component in the entire device.

[0083] In an embodiment, the middle frame 19 and / or a conductive part of the rear cover 21 may serve as a reference ground of the electronic device 10. The side frame 11, the PCB 17, and the like of the electronic device may be electrically connected to the middle frame for grounding.

[0084] The antenna of the electronic device 10 may be further disposed in the side frame 11. When the side frame 11 of the electronic device 10 is made of a non-conductive material, the radiator of the antenna may be located in the electronic device 10 and disposed along the side frame 11. For example, the radiator of the antenna is disposed close to the side frame 11, to reduce a volume occupied by the radiator of the antenna as much as possible, and is closer to the outside of the electronic device 10, to achieve better signal transmission effect. It should be noted that, that the radiator of the antenna is disposed close to the side frame 11 means that the radiator of the antenna may be tightly attached to the side frame 11, or may be disposed close to the side frame 11. For example, there may be a specific small slit between the radiator of the antenna and the side frame 11.

[0085] The antenna of the electronic device 10 may be further disposed in the casing, for example, a bracketed antenna or a millimeter wave antenna (not shown in FIG. 1). Clearance of the antenna disposed in the housing may be obtained via a slit / hole in any one of the middle frame, and / or the side frame, and / or the rear cover, and / or the display, or via a non-conductive slit / aperture formed between any several of the middle frame, and / or the side frame, and / or the rear cover, and / or the display. The clearance of the antenna may be provided, to ensure radiation performance of the antenna. It should be understood that, the clearance of the antenna may be a non-conductive area formed by any conductive component in the electronic device 10, and the antenna radiates a signal to external space through the non-conductive area. In an embodiment, a form of the antenna 40 may be an antenna form based on a flexible mainboard (flexible printed circuit, FPC), an antenna form based on laser-direct-structuring (laser-direct-structuring, LDS), or an antenna form like a microstrip antenna (microstrip disk antenna, MDA). In an embodiment, the antenna may alternatively use a transparent structure embedded into a screen of the electronic device 10, so that the antenna is a transparent antenna element embedded into the screen of the electronic device 10.

[0086] FIG. 1 shows only an example of some parts included in the electronic device 10. Actual shapes, actual sizes, and actual structures of the parts are not limited to those in FIG. 1.

[0087] It should be understood that, in embodiments of this application, it may be considered that a surface on which the display of the electronic device is located is a front surface, a surface on which the rear cover is located is a rear surface, and a surface on which the side frame is located is a side surface.

[0088] It should be understood that, in embodiments of this application, it is considered that when a user holds the electronic device (the user usually holds the electronic device vertically and faces the screen), an orientation in which the electronic device is located has a top part, a bottom part, a left part, and a right part. It should be understood that, in embodiments of this application, it is considered that when the user holds the electronic device (the user usually holds the electronic device vertically and faces the screen), the orientation in which the electronic device is located has the top part, the bottom part, the left part, and the right part.

[0089] FIG. 2 and FIG. 3 describe two antenna modes in this application. In embodiments in FIG. 2 and FIG. 3, a dipole antenna is used as an example. It should be understood that a specific antenna form and / or antenna shape are / is not used to limit the description of the antenna mode in this application. FIG. 2 is a diagram of current distribution corresponding to a half-wavelength mode (half wavelength mode, HWM, also referred to as a half-wavelength mode or a half mode) of the dipole antenna according to an embodiment. FIG. 3 is a diagram of current distribution corresponding to a one wavelength mode (one wavelength mode, OWM) of the dipole antenna according to an embodiment. In another embodiment of this application, the half-wavelength mode and the one wavelength mode are applicable to another antenna form, and are not only applicable to a wire antenna (wire antenna), but also applicable to a patch antenna (patch antenna). The specific antenna form may be, for example, a planar inverted-L antenna (planar inverted-L antenna, PILA), a planar inverted-F antenna (planar inverted-F antenna, PIFA), an inverted-F antenna (inverted-F antenna, IFA), an inverted-L antenna (inverted-L antenna, ILA), or a monopole (monopole) antenna. In addition, in another embodiment of this application, a radiator of the antenna may be in any shape / form (for example, a straight form, a bent form, a linear form, a sheet form, a split form, or an integrated form), and an operating mode of the antenna is not affected.1. Half-wavelength mode

[0090] As shown in FIG. 2, a dipole antenna 101 is in an HWM. In this mode, currents on a radiator of the antenna are the same in direction, and there is one current strong point. For example, a current amplitude is largest at a center of the radiator of the antenna, and is smallest at two ends of the radiator.2. One wavelength mode

[0091] As shown in FIG. 3, the dipole antenna 101 is in an OWM. In this mode, currents on two sides of the radiator (for example, two sides of a middle position of the radiator) of the antenna are reverse in direction, and there are two current strong points and three current zero points. For example, a current amplitude is smallest at the two ends and the center of the radiator, and is largest at middle positions between a center point of the radiator and the two ends.

[0092] That the currents are the same / reverse in direction mentioned in embodiments of this application should be understood as that directions of main currents on the radiator are the same / reverse. For example, the currents are integrally the same / reverse in direction. When co-directionally distributed currents are excited on an annular radiator (for example, a current path is also annular), it should be understood that, although main currents excited on conductors (for example, conductors around a slit, or conductors on two sides of the slit) on two sides of the annular conductor are reverse in direction, the main currents still meet a definition of the co-directionally distributed currents in this application.

[0093] It can be learned from an electromagnetic induction theorem that the current strong point mentioned in embodiments of this application may correspond to an electric field zero point and the current zero point may correspond to an electric field strong point. A strong point and a zero point are relative concepts, are conventionally understood by a person skilled in the art, are not largest and smallest in a strict sense, and are not merely a point, but an area. For example, an area in which an amplitude is far greater than an average value may be a strong point, and an area in which an amplitude is far less than the average value may be a zero point. A largest / smallest amplitude and the like should be accordingly understood. A person skilled in the art may understand that a ground end generally corresponds to a current strong point (or an electric field zero point), an open end generally corresponds to an electric field strong point (or a current zero point), a current reverse area generally corresponds to a current zero point (or an electric field strong point), and an electric field reverse area generally corresponds to an electric field zero point (or a current strong point).

[0094] It should be understood that a diagram of current distribution shown in each embodiment of this application shows only a general current direction of an antenna structure at a moment when an electrical signal is fed into a radiator. The schematic current distribution is a distribution diagram of currents (for example, a current whose current amplitude exceeds 50%) that are simplified for ease of understanding. For example, current distribution on a ground plane is simplified to current distribution in some areas close to the radiator, and only a general direction of the current distribution is shown. It should be noted that a current distribution arrow is merely used as an example of a current direction, and does not indicate that a current flow area is limited to a position shown by the arrow.

[0095] FIG. 4 and FIG. 5 are diagrams of current distribution of a radiator of a bent antenna according to an embodiment of this application.

[0096] Two ends of the dipole antenna shown in FIG. 2 and FIG. 3 are bent inward to form shapes shown in FIG. 4 and FIG. 5. The HWM and the OWM still exist. In this case, currents generated by the dipole antenna 101 in the HWM are shown in FIG. 4, and the currents are co-directionally distributed around a middle slit. Currents generated by the dipole antenna 101 in the OWM are shown in FIG. 5, and the currents are reversely distributed around the middle slit. Current amplitude features are the same as or similar to those shown in FIG. 2 and FIG. 3.

[0097] FIG. 6 and FIG. 7 show two modes of a slot antenna. FIG. 8 is a diagram of a common-mode structure of a slot antenna and distribution of corresponding currents, electric fields, and magnetic currents according to this application. FIG. 9 is a diagram of a differential-mode structure of another slot antenna and distribution of corresponding currents, electric fields, and magnetic currents according to this application.1. Common mode (common mode, CM) mode of a slot antenna

[0098] A slot antenna 60 shown in (a) in FIG. 6 may be formed by a hollowed-out slot or slit 61 disposed in a radiator of the slot antenna, or formed by enclosing the slot or slot 61 by the radiator of the slot antenna and a ground (for example, a ground plane, which may be a PCB). The slot 61 may be formed by slotting the ground plane. An opening 62 is disposed on a side of the slot 61, and the opening 62 may be specifically disposed at a middle position of the side. The middle position of the side of the slot 61 may be, for example, a geometric midpoint of the slot antenna, or a midpoint of an electrical length of the radiator. For example, an area of the opening 62 on the radiator covers the middle position of the side. A feed part may be connected to the opening 62, and anti-symmetrical feed (anti-symmetrical feed) is used. It should be understood that the anti-symmetrical feed may be understood as that positive and negative electrodes of the feed part are respectively connected to two ends of the radiator. Signals output from the positive and negative electrodes of the feed part have a same amplitude but opposite phases. For example, a phase difference is 180°±10°.

[0099] (b) in FIG. 6 shows distribution of currents, electric fields, and magnetic currents of the slot antenna 60. As shown in (b) in FIG. 6, currents are co-directionally distributed around the slot 61 and on a conductor (for example, the ground plane and / or the radiator 60) around the slot 61, electric fields are reversely distributed on two sides of a middle position of the slot 61, and magnetic currents are reversely distributed on the two sides of the middle position of the slot 61. As shown in (b) in FIG. 84, electric fields at the opening 62 (for example, a feed position) are the same in direction, and magnetic currents at the opening 62 (for example, the feed position) are the same in direction. Based on the co-directional magnetic currents at the opening 62 (the feed position), such feed shown in (a) in FIG. 6 may be referred to as slot antenna CM feed. Based on asymmetric distribution (for example, co-directional distribution) of currents on the radiator on two sides of the opening 62, or based on co-directional distribution of the currents around the slot 61 and on the conductor around the slot 61, such slot antenna mode shown in (b) in FIG. 6 may be referred to as a CM mode of the slot antenna (which may also be referred to as a CM mode for short, for example, for the slot antenna, the CM mode is the CM mode of the slot antenna). Distribution of the electric fields, the currents, and the magnetic currents shown in (b) in FIG. 6 may be referred to as a CM mode electric field, a CM mode current, and a CM mode magnetic current of the slot antenna.

[0100] The CM mode current and the CM mode electric field of the slot antenna are generated by using slot antenna bodies on two sides of the middle position of the slot antenna 60 as an antenna operating in a half-wavelength mode. The magnetic field is weak at the middle position of the slot antenna 60 and strong at two ends of the slot antenna 60. The electric field is strong at the middle position of the slot antenna 60 and weak at two ends of the slot antenna 60.

[0101] It should be understood that the CM mode of the slot antenna may be understood as being evolved from a half-wavelength mode of the bent dipole antenna shown in FIG. 4, and the CM mode and the half-wavelength mode have same current strong point distribution. A structural difference between the two antennas lies only in that a ground plane electrically connected to the dipole antenna is added, to form a slot antenna structure.4. Differential mode (differential mode, DM) mode of a slot antenna

[0102] A slot antenna 70 shown in (a) in FIG. 7 may be formed by a hollowed-out slot or slit 72 disposed in a radiator of the slot antenna, or formed by enclosing the slot or slot 72 by the radiator of the slot antenna and a ground (for example, a ground plane, which may be a PCB). The slot 72 may be formed by slotting the ground plane. A feed part is connected to a middle position 71 of the slot 72, and symmetrical feed (symmetrical feed) is used. It should be understood that the symmetrical feed may be understood as that one end of the feed part is connected to the radiator and the other end is grounded. A joint (feed point) between the feed part and the radiator is located in a center of the radiator. The center of the radiator may be, for example, a midpoint of an integrated structure, or a midpoint of an electrical length (or an area within a specific range near the midpoint). A middle position of one side edge of the slot 72 is connected to a positive electrode of the feed part, and a middle position of the other side edge of the slot 72 is connected to a negative electrode of the feed part. The middle position of the side edge of the slot 72 may be, for example, a middle position of the slot antenna 60 / a middle position of the ground, for example, a geometric center of the slot antenna, or a midpoint of an electrical length of the radiator. For example, a joint between the feed part and the radiator covers the middle position 51 of the side.

[0103] (b) in FIG. 7 shows distribution of currents, electric fields, and magnetic currents of the slot antenna 70. As shown in (b) in FIG. 7, on a conductor (for example, the ground plane and / or the radiator 60) around the slot 72, currents are distributed around the slot 72 and are reversely distributed on two sides of the middle position of the slot 72, electric fields are co-directionally distributed on the two sides of the middle position 71, and magnetic currents are co-directionally distributed on the two sides of the middle position 71. Magnetic currents at the feed part are reversely distributed (not shown). Based on reverse distribution of the magnetic currents at the feed part, such feed shown in (a) in FIG. 7 may be referred to as slot antenna DM feed. Based on symmetric distribution (for example, reverse distribution) of currents on two sides of the joint between the feed part and the radiator, or based on symmetric distribution (for example, reverse distribution) of currents around the slit 71, such slot antenna mode shown in (b) in FIG. 7 may be referred to as a DM mode of the slot antenna (which may also be referred to as a DM mode for short, for example, for the slot antenna, the DM mode is the DM mode of the slot antenna). Distribution of the electric fields, the currents, and the magnetic currents shown in (b) in FIG. 7 may be referred to as a DM mode electric field, a DM mode current, and a DM mode magnetic current of the slot antenna.

[0104] The DM mode current and the DM mode electric field of the slot antenna are generated by using the entire slot antenna 70 as an antenna operating in a one wavelength mode. The current is weak at the middle position of the slot antenna 70 and strong at two ends of the slot antenna 70. The electric field is strong at the middle position of the slot antenna 70 and weak at two ends of the slot antenna 70.

[0105] It should be understood that the DM mode of the slot antenna may be understood as being evolved from a one wavelength mode of the bent dipole antenna shown in FIG. 5, and the DM mode and the one wavelength mode have same current strong point distribution. A structural difference between the two antennas lies only in that a ground plane electrically connected to the dipole antenna is added, to form a slot antenna structure.

[0106] It should be understood that the radiator of the slot antenna may be understood as a metal mechanical part (for example, including a part of the ground plane) that generates radiation, may include an opening as shown in FIG. 6 or may be a complete loop as shown in FIG. 7, and may be adjusted based on an actual design or production requirement. For example, in the CM mode of the slot antenna, the complete loop radiator may also be used as shown in FIG. 7, two feed points are disposed at a middle position of the radiator on one side of the slot 61, and an anti-symmetrical feed manner is used. For example, signals of a same amplitude and opposite phases are respectively fed into two ends of an original opening position, so that effect similar to that of the antenna structure shown in FIG. 6 may also be achieved. Correspondingly, in the DM mode of the slot antenna, a radiator including an opening may also be used as shown in FIG. 6, and a symmetrical feed manner is used at two ends of the opening position. For example, a same feed source signal is separately fed into two ends of the radiator on two sides of the opening, so that effect similar to that of the antenna structure shown in FIG. 7 may also be achieved.

[0107] FIG. 8 and FIG. 9 show patterns of the slot antenna. FIG. 8 shows a pattern generated by the slot antenna shown in FIG. 6 in the CM mode. FIG. 9 shows a pattern generated by the slot antenna shown in FIG. 7 in the DM mode.

[0108] A radiation direction of maximum radiation generated by the slot antenna in the CM mode is in a z direction, as shown in FIG. 8. A radiation direction of maximum radiation generated by the slot antenna in the DM mode deviates from the z direction, as shown in FIG. 9.

[0109] When an operating bandwidth of the slot antenna is expanded based on a resonance generated in the CM mode and a resonance generated in the DM mode, in this operating frequency band, a pattern generated by the slot antenna changes (directions of maximum radiation generated at different frequencies are different). All subunits in a (multi-input multi-output, MIMO) antenna system may have different maximum radiation directions, to implement omnidirectional coverage of radiation beams (a good gain is obtained in each direction, to improve communication performance of the electronic device). Therefore, when the slot antenna is used as a subunit in the MIMO antenna system, a pattern change in an operating frequency band may result in poor omnidirectivity of the MIMO antenna system.

[0110] In addition, due to characteristics of the CM mode and the DM mode, an efficiency dip occurs in an operating frequency band of the slot antenna, resulting in poor system efficiency and radiation efficiency of the slot antenna within some frequency ranges.

[0111] Embodiments of this application provide an antenna structure and an electronic device. A slit is disposed on a ground plane of the antenna structure. Due to the slit, the antenna structure may have at least two different current paths when generating radiation. Correspondingly, the antenna structure may generate at least two different resonances, so that the antenna structure has a good radiation characteristic.

[0112] FIG. 10 is a diagram of an antenna structure 200 according to an embodiment of this application.

[0113] As shown in FIG. 10, the antenna structure 200 includes a first radiator 210, a second radiator 220, a ground plane 230, and a first feed part 240.

[0114] A first end of the first radiator 210 and a first end of the second radiator 220 are opposite to each other and are not in contact with each other. The first end of the first radiator 210 and the first end of the second radiator 220 are open ends, and a second end of the first radiator 210 and a second end of the second radiator 220 are ground ends.

[0115] In an embodiment, a distance between the first end of the first radiator 210 and the first end of the second radiator 220 is greater than or equal to 0.1 mm and less than or equal to 5 mm. It should be understood that the distance between the first end of the first radiator 210 and the first end of the second radiator 220 may be understood as a width of a slit formed between the first end of the first radiator 210 and the first end of the second radiator 220.

[0116] The ground plane 230 is a metal layer, and includes a first ground position 231, a second ground position 232, and a first slit 252. A first gap is formed between the ground plane 230 and the first radiator 210, and a second gap is formed between the ground plane 230 and the second radiator 220. An edge of the ground plane 230 between the first ground position 231 and the second ground position 232 further includes a third ground position 233. The first ground position 231 is coupled to the second end of the first radiator 210, so that the second end of the first radiator 210 is grounded. The second ground position 232 is coupled to the second end of the second radiator 220, so that the second end of the second radiator 220 is grounded. The first slit 252 extends from the edge of the ground plane 230 to the inside of the ground plane 230, and at least a part of the first slit 252 is located between the first ground position 231 and the second ground position 232.

[0117] It should be understood that, for ease of understanding of the technical solutions provided in this application, it may be considered that a position at which the first slit 252 is connected to the edge of the ground plane 230 is the third ground position 233, and the third ground position 233 is a virtual position.

[0118] A first end of the first feed part 240 is coupled to the ground plane 230 on a first side of the first slit 252, and a second end of the first feed part 240 is coupled to the ground plane 230 on a second side of the first slit 252.

[0119] It should be understood that, for brevity of description, in embodiments of this application, a coupling connection is described by using only an electrical connection as an example. In actual production or design, the coupling connection may alternatively be implemented as indirect coupling.

[0120] It should be understood that, in the technical solution provided in this embodiment of this application, the ground plane 230 is provided with the first slit 252 between the two ground positions of the radiators of the antenna structure 200, and the first feed part 240 is coupled to the ground plane on the two sides of the first slit 252, to feed an electrical signal for the antenna structure 200. The antenna structure 200 may generate a first resonance and a second resonance. A frequency of the first resonance is lower than a frequency of the second resonance. An operating bandwidth of the antenna structure 200 may be expanded based on the first resonance and the second resonance.

[0121] In an embodiment, the antenna structure 200 further includes an electronic element 251. The electronic element 251 is coupled between the first end of the first feed part 240 and the ground plane on the first side of the first slit 252. The first end of the first feed part 240 is coupled to the ground plane on the first side of the first slit 252 via a first end of the electronic element 251, and a second end of the electronic element 251 is coupled to the ground plane on the second side of the first slit 252.

[0122] It should be understood that, when the first feed part 240 feeds an electrical signal, there may be two different current paths due to a current selection characteristic (high-pass characteristic) of the electronic element 251. In a first current path, the electronic element 251 is in an open-circuit state, and a current flows through the edge of the ground plane between the first ground position 231 and the second ground position 232 and the ground plane around the first slit 252. In a second current path, the electronic element 251 is in a short-circuit state, and a current flows through the edge of the ground plane between the first ground position 231 and the second ground position 232 and the electronic element 251.

[0123] The two different current paths correspond to the foregoing two different resonances. The first current path may correspond to the first resonance, and the second current path may correspond to the second resonance. The electronic element 251 may be equivalent to being in different electrical connection states in a resonant frequency band of the first resonance and a resonant frequency band of the second resonance (for example, the electronic element 251 may be equivalent to being in an open circuit at a resonance point of the first resonance, and the electronic element 251 may be equivalent to being in a short circuit at a resonance point of the second resonance).

[0124] In an embodiment, when the first feed part 240 is coupled to the ground plane on the first side and the second side of the first slit 252 through a coaxial cable, an inner core of the coaxial cable is coupled to the ground plane 230 on the first side of the first slit 252, and a sheath of the coaxial cable is coupled to the ground plane 230 on the second side of the first slit 252.

[0125] In an embodiment, at the resonance point of the first resonance, currents on edges of the ground plane 230 on the two sides of the third ground position 233 (the first slit 252) are the same in direction; and at the resonance point of the second resonance, currents on edges of the ground plane 230 on the two sides of the third ground position 233 (the first slit 252) are the same in direction.

[0126] It should be understood that the first slit 252 disposed on the ground plane 230 has little impact on current distribution and electric field distribution on the first radiator 210 and the second radiator 220. At the resonance point of the first resonance and the resonance point of the second resonance, the currents on the edges of the ground plane 230 on the two sides of the third ground position 233 are the same in direction. Because the current distribution and the electric field distribution on the first radiator 210 and the second radiator 220 do not change, characteristics of the CM mode in the foregoing embodiment are maintained in both a first mode in which the first resonance is generated and a second mode in which the second resonance is generated.

[0127] Because both the first mode and the second mode are CM modes, a maximum radiation direction of a pattern corresponding to the first resonance is approximately the same as a maximum radiation direction of a pattern corresponding to the second resonance, and no pattern change occurs. This facilitates application to a MIMO antenna system.

[0128] In addition, because both the first mode and the second mode are CM modes, no efficiency dip is generated in an operating frequency band formed by the first resonance and the second resonance, so that the antenna structure 200 can have good radiation efficiency and system efficiency.

[0129] In an embodiment, a physical length of the first slit 252 between the edge (the third ground position 233) of the ground plane and a position at which the first feed part 240 is electrically connected to the ground plane 230 is less than half of a physical length L1 of the first slit 252.

[0130] It should be understood that, due to an error in engineering processing, when a feed position of the first feed part 240 is in an upper half area of the first slit 252, the antenna structure 200 can have good radiation efficiency and system efficiency. For brevity of description, in this embodiment of this application, only an example in which the first feed part 240 is electrically connected between the ground plane on the two sides of the third ground position 233 is used for description. In an embodiment, an electrical length D1 of the first slit 252 may fall within a range (a quarter of a first wavelength D0±10%), and the first wavelength is a wavelength corresponding to the first resonance. In an embodiment, due to an error in engineering processing, the electrical length D1 of the first slit 252 and the first wavelength D0 may satisfy: D0×20%≤D1≤D0×30%.

[0131] It should be understood that the first wavelength may be a vacuum wavelength. Because there is a specific conversion relationship between a vacuum wavelength and a dielectric wavelength, a corresponding dielectric wavelength may be obtained through calculation.

[0132] When the electrical length of the first slit 252 is approximately the quarter of the first wavelength, and in the resonant frequency band of the first resonance, a current is transmitted from the first side of the first slit 252 (the third ground position 233) to the second side through the ground plane around the first slit 252, an electrical length of a current path is approximately half of the first wavelength. After the current passes through the path with the electrical length of the half wavelength, a phase change is 360°, so that currents on the ground plane 230 on the two sides of the third ground position 233 are the same in direction.

[0133] In an embodiment, the electrical length D1 of the first slit 252 and the first wavelength D0 may satisfy: D1≤D0×25%×N, where N is a positive integer.

[0134] It should be understood that, when the electrical length D1 of the first slit 252 is approximately N times the quarter of the first wavelength D0, and correspondingly, in the resonant frequency band of the first resonance, a current is transmitted from the first side of the first slit 252 (the third ground position 233) to the second side through the ground plane around the first slit 252, an electrical length of a current path is approximately N times half of the first wavelength. After the current passes through the path with the electrical length of the N times the half wavelength, a phase change is N times 360°, so that currents on the ground plane 230 on the two sides of the third ground position 233 may also be the same in direction.

[0135] In an embodiment, the physical length L1 of the first slit 252, a physical length L2 of the first radiator 210, and a physical length L3 of the second radiator 220 may satisfy: L 2 + L 3 × 25 % ≤ L 1 ≤ L 2 + L 3 × 100 % .

[0136] In an embodiment, the first slit 252 may alternatively be in a straight line shape, a fold line shape, an arc shape, a T shape, or the like. This is not limited in embodiments of this application.

[0137] It should be understood that, when the first slit 252 is in the foregoing different shapes, the physical length of the first slit may be understood as a sum of physical lengths of parts of the first slit 252 that extend in different directions.

[0138] In an embodiment, a physical length of an edge (a contour) of the first slit 252 is greater than or equal to (L2+L3)×50% and less than or equal to (L2+L3)×200%.

[0139] It should be understood that the physical length of the edge (contour) of the first slit 252 may be understood as a physical length of a path in which a current is transmitted along the ground plane around the first slit 252.

[0140] In an embodiment, a width of the first slit 252 is greater than or equal to 0.1 mm and less than or equal to 5 mm. It should be understood that widths of parts of the first slit 252 may be different. That the width of the first slit 252 is greater than or equal to 0.1 mm and less than or equal to 5 mm may be understood as that a width of a widest part of the first slit 252 is less than or equal to 5 mm and a width of a narrowest part is greater than or equal to 0.1 mm.

[0141] It should be understood that the physical length and the width of the first slit 252 are related to the electrical length of the first slit 252, and the physical length and the width of the first slit 252 may be determined based on actual production or design.

[0142] In an embodiment, the electronic element 251 may include a capacitor, or may be equivalent to a capacitor. In an embodiment, a capacitance value (an equivalent capacitance value) of the electronic element 251 may be greater than or equal to 0.3 pF and less than or equal to 3 pF.

[0143] It should be understood that the capacitance value (or the equivalent capacitance value) of the electronic element 251 may be determined based on an operating frequency band of the antenna structure 200. In an embodiment, the operating frequency band of the antenna structure 200 includes at least a part of a low frequency band (low band, LB) (698 MHz to 960 MHz), and the capacitance value (or the equivalent capacitance value) of the electronic element 251 may be greater than or equal to 0.3 pF and less than or equal to 3 pF. In an embodiment, the operating frequency band of the antenna structure 200 includes at least a part of a middle frequency band (middle band, MB) (1710 MHz to 2170 MHz) or a high frequency band (high band, HB) (2300 MHz to 2690 MHz), and the capacitance value (or the equivalent capacitance value) of the electronic element 251 may be greater than or equal to 0.3 pF and less than or equal to 2 pF.

[0144] In an embodiment, the electronic element 251 may include an inductor, or may be equivalent to an inductor.

[0145] It should be understood that an inductance value (or an equivalent inductance value) of the electronic element 251 may be determined based on the operating frequency band of the antenna structure 200.

[0146] In an embodiment, a difference between a frequency of the resonance point of the second resonance and a frequency of the resonance point of the first resonance falls within a threshold, so that the first resonance and the second resonance jointly form one operating frequency band. It should be understood that, that the first resonance and the second resonance jointly form one operating frequency band may be understood as that, in an S-parameter diagram, a largest value of an S11 curve between the resonance point of the first resonance and the resonance point of the second resonance is less than a preset value (for example, -4 dB).

[0147] It should be understood that the threshold may be determined based on the operating frequency band of the antenna structure 200. In an embodiment, the operating frequency band of the antenna structure 200 includes at least a part of the LB (698 MHz to 960 MHz), and the difference between the frequency of the resonance point of the second resonance and the frequency of the resonance point of the first resonance is greater than or equal to 100 MHz and less than or equal to 300 MHz. In an embodiment, the operating frequency band of the antenna structure 200 includes at least a part of the middle frequency band (middle band, MB) (1710 MHz to 2170 MHz), and the difference between the frequency of the resonance point of the second resonance and the frequency of the resonance point of the first resonance is greater than or equal to 150 MHz and less than or equal to 800 MHz. In an embodiment, the operating frequency band of the antenna structure 200 includes at least a part of the high frequency band (high band, HB) (2300 MHz to 2690 MHz), and the difference between the frequency of the resonance point of the second resonance and the frequency of the resonance point of the first resonance is greater than or equal to 200 MHz and less than or equal to 1000 MHz.

[0148] In an embodiment, the physical length L2 of the first radiator 210 and the physical length L3 of the second radiator 220 may satisfy: L2×70%≤L3≤L2×130%.

[0149] In an embodiment, a sum of an electrical length D2 of the first radiator 210 and an electrical length D3 of the second radiator 220 falls within a range (half of the first wavelength±10%).

[0150] In an embodiment, the electrical length D2 of the first radiator 210 and the electrical length D3 of the second radiator 220 may satisfy: D2×70%≤D3≤D2×130%.

[0151] In an embodiment, the physical length L2 of the first radiator 210 and the physical length L3 of the second radiator 220 may satisfy: L2×90%≤L3≤L2×110%.

[0152] In an embodiment, the electrical length D2 of the first radiator 210 and the electrical length D3 of the second radiator 220 may satisfy: D2×90%≤D3≤D2×110%.

[0153] It should be understood that the electrical length of the first radiator 210 and the electrical length of the second radiator 220 need to be approximately the same, so that the difference between the frequency of the resonance point of the second resonance and the frequency of the resonance point of the first resonance falls within the threshold, and the first resonance and the second resonance may jointly form the operating frequency band, to expand the operating bandwidth of the antenna structure 200. In an embodiment, the physical length of the first radiator 210 and the physical length of the second radiator 220 need to be approximately the same.

[0154] In an embodiment, the physical length L2 of the first radiator 210 is the same as the physical length L3 of the second radiator 220. In an embodiment, a slit is formed between the first end of the first radiator 210 and the first end of the second radiator 220, the first radiator 210 and the second radiator 220 are symmetrical along a virtual axis of the slit, and the virtual axis is perpendicular to an extension direction of the first radiator 210 or the second radiator 220, and the slit has a same width on two sides of the symmetrical axis.

[0155] In an embodiment, the electrical length D2 of the first radiator 210 and the electrical length D3 of the second radiator 220 are approximately the same, and both fall within the range (the quarter of the first wavelength±10%).

[0156] It should be understood that, as symmetry of the first radiator 210 and the second radiator 220 is improved, the antenna structure 200 may have a better radiation characteristic. For example, better symmetry of the first radiator 210 and the second radiator 220 indicates a greater proportion of a CM mode and a smaller proportion of a DM mode in the first resonance and the second resonance, and higher radiation efficiency and system efficiency in the operating frequency band.

[0157] FIG. 11 is a diagram of another antenna structure 300 according to an embodiment of this application.

[0158] As shown in FIG. 11, a difference between the antenna structure 300 and the antenna structure 200 shown in FIG. 10 lies only in that no slit is provided on a ground plane, and a feed part of the antenna structure 300 is electrically connected between a first end and a second end of a first radiator. A characteristic impedance of the feed part of the antenna structure 300 is 1500 ohms, so that the antenna structure 300 excites, only via the feed part, a resonance generated in a CM mode.

[0159] FIG. 12 to FIG. 14 show simulation results of the antenna structures shown in FIG. 10 and FIG. 11. FIG. 12 is a diagram of S-parameter simulation results of the antenna structures shown in FIG. 10 and FIG. 11. FIG. 13 is a Smith chart of the antenna structures shown in FIG. 10 and FIG. 11. FIG. 14 is a diagram of simulation results of system efficiency of the antenna structures shown in FIG. 10 and FIG. 11.

[0160] It should be understood that a characteristic impedance of a first feed part of the antenna structure 200 shown in FIG. 10 is 50 ohms, and the first feed part is electrically connected between the ground plane on two sides of a third ground position.

[0161] As shown in FIG. 12, the antenna structure 200 may generate resonances near 1.6 GHz (a first resonance) and near 1.9 GHz (a second resonance). However, the antenna structure 300 can generate a resonance only near 1.8 GHz. When S11<-4 dB is used as a boundary, an operating bandwidth of the antenna structure 200 is greater than 700 MHz, and is far greater than an operating bandwidth of the antenna structure 300.

[0162] As shown in FIG. 13, between 1 GHz and 2.6 GHz, the antenna structure 200 may generate two resonances (impedance curves have an intersection), and the antenna structure 300 can generate only one resonance.

[0163] As shown in FIG. 14, in an operating frequency band of the antenna structure 200, there is no efficiency dip in system efficiency, and the system efficiency is greater than -4 dB.

[0164] FIG. 15 to FIG. 18 are diagrams of current distribution and electric field distribution of the antenna structure 200 shown in FIG. 10. FIG. 15 is a diagram of current distribution of the antenna structure 200 shown in FIG. 10 at a first resonance (for example, 1.6 GHz). FIG. 16 is a diagram of current distribution of the antenna structure 200 shown in FIG. 10 at a second resonance (for example, 1.9 GHz). FIG. 17 is a diagram of electric field distribution of the antenna structure 200 shown in FIG. 10 at the first resonance (for example, 1.6 GHz). FIG. 18 is a diagram of electric field distribution of the antenna structure 200 shown in FIG. 10 at the second resonance (for example, 1.9 GHz).

[0165] FIG. 15 shows a current path (the first current path in the foregoing embodiment) of the antenna structure 200 at the first resonance. In the current path, an electronic element may be equivalent to being in an open circuit, a third ground position is in an open-circuit state, and a current flows through a ground plane around a first slit.

[0166] FIG. 16 shows a current path (the second current path in the foregoing embodiment) of the antenna structure 200 at the second resonance. In the current path, the electronic element may be equivalent to being in a short circuit, the third ground position is in a short-circuit state, and the current flows through the third ground position.

[0167] As shown in FIG. 15 to FIG. 18, the first slit disposed on the ground plane has little impact on current distribution and electric field distribution on a first radiator and a second radiator. In addition, both the current distribution and the electric field distribution of the antenna structure at the first resonance and the second resonance maintain characteristics of the CM mode in the foregoing embodiment.

[0168] FIG. 19 and FIG. 20 show patterns of the antenna structure 200 shown in FIG. 10 at the first resonance (for example, 1.6 GHz) and the second resonance (for example, 1.9 GHz).

[0169] As shown in FIG. 19 and FIG. 20, because both a first mode and a second mode are CM modes, a maximum radiation direction of the pattern corresponding to the first resonance is approximately the same as a maximum radiation direction of the pattern corresponding to the second resonance, there is a high gain in a z direction, and no pattern change occurs.

[0170] FIG. 21 to FIG. 23 are diagrams of another antenna structure 200 according to an embodiment of this application.

[0171] It should be understood that a difference between the antenna structure 200 shown in FIG. 21 to FIG. 23 and the antenna structure 200 shown in FIG. 10 lies only in a shape of a first slit disposed at a third ground position of a ground plane.

[0172] As shown in FIG. 21, a first slit is in an L shape. In an embodiment, the first slit may alternatively be in a fold line shape.

[0173] As shown in FIG. 22, a first slit is in a T shape. An electrical length of the first slit shown in FIG. 10 and FIG. 21 falls within a range (a quarter of a first wavelength±10%), and an electrical length of the first slit shown in FIG. 22 falls within a range (half of the first wavelength±10%).

[0174] A difference between a first slit shown in FIG. 23 and the first slit shown in FIG. 22 lies only in that widths of the first slits are different, and electrical lengths of the first slit shown in FIG. 23 and the first slit shown in FIG. 22 are approximately the same.

[0175] FIG. 24 to FIG. 27 show simulation results of the antenna structures shown in FIG. 10 and FIG. 21 to FIG. 23. FIG. 24 is a diagram of S-parameter simulation results of the antenna structures shown in FIG. 10 and FIG. 21 to FIG. 23. FIG. 25 is a Smith chart of the antenna structures shown in FIG. 10 and FIG. 21 to FIG. 23. FIG. 26 is a diagram of simulation results of system efficiency of the antenna structures shown in FIG. 10 and FIG. 21 to FIG. 23. FIG. 27 is a diagram of simulation results of radiation efficiency of the antenna structures shown in FIG. 10 and FIG. 21 to FIG. 23.

[0176] As shown in FIG. 24, the antenna structures shown in FIG. 10 and FIG. 21 to FIG. 23 may generate a first resonance and a second resonance. When S11<-4 dB is used as a boundary, all the antenna structures have a wide operating bandwidth. A resonance point of the first resonance and a resonance point of the second resonance may be offset by adjusting the electrical length or the shape of the first slit.

[0177] As shown in FIG. 25, between 1 GHz and 2.6 GHz, the antenna structures shown in FIG. 10 and FIG. 21 to FIG. 23 each may generate two resonances (impedance curves have an intersection).

[0178] As shown in FIG. 26, in each operating frequency band of the antenna structures shown in FIG. 10 and FIG. 21 to FIG. 23, there is no efficiency dip in system efficiency, and the system efficiency is greater than -4 dB.

[0179] As shown in FIG. 27, in each operating frequency band of the antenna structures shown in FIG. 10 and FIG. 21 to FIG. 23, there is no efficiency dip in radiation efficiency, and the radiation efficiency is greater than -3 dB.

[0180] FIG. 28 is a diagram of an electronic device 10 according to an embodiment of this application.

[0181] It should be understood that all the antenna structures 200 provided in embodiments of this application may be used in the electronic device shown in FIG. 1.

[0182] As shown in FIG. 28, the electronic device 10 further includes a side frame 11, and the side frame 11 includes a conductive part. In an embodiment, the side frame 11 includes at least two conductive parts and at least one non-conductive part, and the conductive parts are connected through the non-conductive part. In an embodiment, the non-conductive part of the side frame 11 is a non-conductive gap, and is connected to the conductive parts by filling an insulation material, to form the complete side frame 11.

[0183] The side frame 11 has a first position 201, a second slit 202, and a second position 203, and the second slit 202 is located between the first position 201 and the second position 203.

[0184] A first radiator 210 includes at least a part of the side frame 11 between the first position 201 and the second slit 202, and a second radiator 220 includes at least a part of the side frame 11 between the second slit 202 and the second position 203. A first end of the first radiator 210 and a first end of the second radiator 220 are open ends.

[0185] In an embodiment, a first gap is formed between an edge of a ground plane 230 and the first radiator 210, and a second gap is formed between an edge of the ground plane 230 and the second radiator 220.

[0186] In an embodiment, the electronic device 10 includes a first side 204 and a second side 205 that intersect at an angle. In an embodiment, the first position 201, the second slit 202, and the second position 203 may all be located on the first side 204. In an embodiment, at least one of the first position 201, the second slit 202, and the second position 203 may be located on the second side 205.

[0187] In an embodiment, a clearance of the antenna structure 200 is less than 1 mm. In an embodiment, a clearance of the antenna structure 200 is greater than or equal to 0 and less than or equal to 0.7 mm.

[0188] It should be understood that the clearance of the antenna structure 200 in the electronic device 10 may be understood as a shortest distance between a radiator (for example, the first radiator or the second radiator) of the antenna structure 200 and the ground plane 230.

[0189] In an embodiment, the electronic device 10 may further include a PCB, and the PCB may include the ground plane in the antenna structure in the foregoing embodiment. In an embodiment, a ground plane layer (metal layer) in the PCB may be used as the ground plane in the antenna structure in the foregoing embodiment. The first slit may be formed by hollowing out the ground plane layer.

[0190] FIG. 29 is a diagram of another antenna structure 200 according to an embodiment of this application.

[0191] As shown in FIG. 29, the antenna structure 200 may further include a third radiator 310 and a second feed part 320, and the second feed part 320 is different from a first feed part 240.

[0192] It should be understood that, that the second feed part 320 is different from the first feed part 240 may be understood as that the second feed part 320 and the first feed part 240 are different radio frequency channels in a radio frequency chip (RF IC).

[0193] A first end of the third radiator 310 and a second end of the third radiator 310 are open ends.

[0194] A central area of the third radiator 310 includes a feed point 311, and the second feed part 320 is coupled to the feed point 311.

[0195] It should be understood that the central area of the third radiator 310 may be understood as a region formed by points that are within 5 mm away from a geometric center of the third radiator 310. A difference between the antenna structure 200 shown in FIG. 29 and the antenna structure 200 in the foregoing embodiment lies only in that the antenna structure 200 shown in FIG. 29 includes the third radiator 310 and the second feed part 320.

[0196] In the antenna structure 200 shown in FIG. 29, a first radiator 210, a second radiator 220, and the first feed part 240 may form a first antenna element, and the first antenna element may operate in a CM mode of a slot antenna. The third radiator 310 and the second feed part 320 may form a second antenna element, and the second antenna element may operate in a CM mode of a wire antenna. Because electric fields generated by the first antenna element and the second antenna element are orthogonal ((integrally orthogonal) an inner product of the electric fields in a far field is zero), there is good isolation between the first antenna element and the second antenna element.

[0197] In an embodiment, a frequency of an electrical signal fed by the first feed part 240 is the same as a frequency of an electrical signal fed by the second feed part 320.

[0198] In an embodiment, the first radiator 210 and the second radiator 220 are configured to generate a first resonance and a second resonance. The third radiator 310 is configured to generate a third resonance. A resonant frequency band formed by the first resonance and the second resonance includes a first frequency band. A resonant frequency band formed by the third resonance also includes the first frequency band. When the antenna structure 200 is used in the electronic device, an operating frequency band of the electronic device may include the first frequency band.

[0199] It should be understood that an operating frequency band of the first antenna element and an operating frequency band of the second antenna element include a same communication frequency band, and may be applied to a multiple-input multiple-output (multi-input multi-output, MIMO) antenna system, so that the electronic device has good communication performance in the frequency band.

[0200] In an embodiment, a distance between the third radiator 310 and the first radiator 210 or the second radiator 210 is less than or equal to 10 mm, so that the radiators of the antenna structure 200 are compactly arranged and occupy small space.

[0201] It should be understood that the distance between the third radiator 310 and the first radiator 210 or the second radiator 210 may be understood as a smallest distance between any point on the third radiator 310 and any point on the first radiator 210 or the second radiator 210.

[0202] In an embodiment, a length L4 of the third radiator 310 in a first direction and a distance L5 between a first ground position and a second ground position in the first direction satisfy: L4×90%≤L5≤L4× 110%. It should be understood that the first direction is an extension direction of a length of the first radiator 210, for example, an x direction.

[0203] It should be understood that, when the length of the third radiator 310 in the first direction is approximately the same as a length of an area in which the first radiator 210 and the second radiator 210 are located in the first direction, the radiators of the antenna structure 200 occupy smallest space, and are more convenient to be disposed in an electronic device with compact space.

[0204] In an embodiment, the electronic device may further include a bracket, and at least a part of the third radiator 310 may be located on a surface of the bracket of the electronic device.

[0205] In an embodiment, the electronic device may further include a rear cover, and at least a part of the third radiator 310 may be located on a surface of the rear cover of the electronic device.

[0206] It should be understood that, when the first radiator 210 and the second radiator 220 include a conductive part of a side frame of the electronic device, the third radiator 310 may be disposed on a surface of a component close to the side frame. A location of the third radiator 310 is not limited in embodiments of this application, and may be disposed based on an actual layout in the electronic device.

[0207] FIG. 30 and FIG. 31 are diagrams of layouts of the antenna structure 200 shown in FIG. 29.

[0208] It should be understood that a difference between FIG. 30 and FIG. 31 lies only in that the antenna structure 200 is disposed at different positions on the ground plane 230.

[0209] A radiator of the antenna structure 200 is disposed along a first side 301 of a ground plane 230. A radiator of the antenna structure 200 shown in FIG. 30 is disposed in an area of a center of the first side 301, and a radiator of the antenna structure 200 shown in FIG. 31 is disposed in an area that deviates from a center of the first side 301. The radiator of the antenna structure 200 shown in FIG. 31 deviates to one side by 25 mm relative to the radiator of the antenna structure 200 shown in FIG. 30.

[0210] FIG. 32 to FIG. 35 show simulation results of the antenna structures shown in FIG. 30 and FIG. 31. FIG. 32 is a diagram of an S-parameter simulation result of the antenna structure shown in FIG. 30. FIG. 33 is a diagram of an S-parameter simulation result of the antenna structure shown in FIG. 31. FIG. 34 is a diagram of a simulation result of system efficiency of the antenna structure shown in FIG. 30. FIG. 35 is a diagram of a simulation result of system efficiency of the antenna structure shown in FIG. 31.

[0211] As shown in FIG. 32, in the antenna structure shown in FIG. 30, the first antenna element (S11) may generate two resonances near 1.7 GHz and 2.2 GHz, and the second antenna element (S22) may generate a resonance near 2 GHz.

[0212] Because the first antenna element operates in the CM mode of the slot antenna, the second antenna element operates in the CM mode of the wire antenna, and the electric fields generated by the two antenna elements are orthogonal in the far field, in the S-parameter simulation result shown in FIG. 32, isolation between the first antenna element and the second antenna element is greater than 40 dB (S12 / S21<-40 dB).

[0213] As shown in FIG. 33, in the antenna structure shown in FIG. 31, the first antenna element (S11) may generate two resonances near 1.7 GHz and 2.2 GHz, and the second antenna element (S22) may generate a resonance near 2 GHz.

[0214] Compared with the antenna structure shown in FIG. 30, the antenna structure shown in FIG. 31 deviates from the center of the first side of the ground plane, and isolation between the first antenna element and the second antenna element decreases and is only greater than 20 dB (S12 / S21<-20 dB). However, a requirement for isolation between subunits in a MIMO antenna system can still be met.

[0215] As shown in FIG. 34, in the antenna structure shown in FIG. 30, both the first antenna element and the second antenna element have good system efficiency. In a corresponding resonant frequency band (S11<-4 dB is used as a boundary), system efficiency is greater than -4 dB.

[0216] As shown in FIG. 35, in the antenna structure shown in FIG. 31, both the first antenna element and the second antenna element have good system efficiency. In a corresponding resonant frequency band (S11<-4 dB is used as a boundary), system efficiency of the antenna structure shown in FIG. 31 is approximately the same as that of the antenna structure shown in FIG. 30.

[0217] In the several embodiments provided in this application, it should be understood that the disclosed system, apparatus, and method may be implemented in another manner. For example, the described apparatus embodiments are merely examples. For example, division into the units is merely logical functional division and may be other division in actual implementation. For example, a plurality of units or components may be combined or integrated into another system, or some features may be ignored or not performed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections may be implemented through some interfaces. The indirect couplings or communication connections between the apparatuses or units may be implemented in an electrical form or another form.

[0218] The foregoing descriptions are merely specific implementations of this application, but are not intended to limit the protection scope of this application. Any variation or replacement readily figured out by a person skilled in the art within the technical scope disclosed in this application shall fall within the protection scope of this application. Therefore, the protection scope of this application shall be subject to the protection scope of the claims.

Claims

1. An antenna structure, comprising: a first radiator and a second radiator, wherein a first end of the first radiator and a first end of the second radiator are opposite to each other and are not in contact with each other, and the first end of the first radiator and the first end of the second radiator are open ends; a ground plane, wherein the ground plane comprises a first ground position, a second ground position, and a first slit, a first gap is formed between the ground plane and the first radiator, a second gap is formed between the ground plane and the second radiator, the first ground position is coupled to a second end of the first radiator, the second ground position is coupled to a second end of the second radiator, the first slit extends from an edge of the ground plane to the inside of the ground plane, and at least a part of the first slit is located between the first ground position and the second ground position; and a first feed part, wherein a first end of the first feed part is coupled to the ground plane on a first side of the first slit, and a second end of the first feed part is coupled to the ground plane on a second side of the first slit.

2. The antenna structure according to claim 1, wherein the antenna structure further comprises an electronic element; and the first end of the first feed part is coupled to the ground plane on the first side of the first slit via a first end of the electronic element, and a second end of the electronic element is coupled to the ground plane on the second side of the first slit.

3. The antenna structure according to claim 2, wherein the electronic element comprises a capacitor, and an equivalent capacitance value of the electronic element is greater than or equal to 0.3 pF and less than or equal to 3 pF.

4. The antenna structure according to any one of claims 1 to 3, wherein a physical length of the first slit between the edge of the ground plane and a position at which the first feed part is electrically connected to the ground plane is less than half of a physical length L1 of the first slit.

5. The antenna structure according to any one of claims 1 to 4, wherein an electrical length of the first slit falls within a range (a quarter of a first wavelength±10%), and the first wavelength is a wavelength corresponding to the first resonance.

6. The antenna structure according to any one of claims 1 to 5, wherein a sum of an electrical length of the first radiator and an electrical length of the second radiator falls within a range (half of the first wavelength+10%), and the first wavelength is the wavelength corresponding to the first resonance.

7. The antenna structure according to any one of claims 1 to 6, wherein the first slit is in a straight line shape, a fold line shape, an arc shape, or a T shape.

8. The antenna structure according to any one of claims 1 to 7, wherein the physical length L1 of the first slit, a physical length L2 of the first radiator, and a physical length L3 of the second radiator satisfy: (L2+L3)×25%≤L1≤(L2+L3)×100%.

9. The antenna structure according to any one of claims 1 to 8, wherein the physical length L2 of the first radiator and the physical length L3 of the second radiator satisfy: L2×70%≤L3≤L2×130%.

10. The antenna structure according to any one of claims 1 to 9, wherein the antenna structure is configured to generate the first resonance and a second resonance, and a frequency of the first resonance is lower than a frequency of the second resonance; at a resonance point of the first resonance, currents on edges of the ground plane on the two sides of the first slit are the same in direction; and at a resonance point of the second resonance, currents on the edges of the ground plane on the two sides of the first slit are the same in direction.

11. The antenna structure according to claim 2 or 3, wherein at a resonance point of the first resonance, a current between the first ground position and the second ground position flows through an edge of the ground plane between the first ground position and the second ground position and the ground plane on the two sides of the first slit; and at a resonance point of the second resonance, a current between the first ground position and the second ground position flows through the edge of the ground plane between the first ground position and the second ground position and the electronic element.

12. The antenna structure according to any one of claims 1 to 11, wherein the antenna structure further comprises a third radiator and a second feed part, and the second feed part is different from the first feed part, wherein a first end of the third radiator and a second end of the third radiator are open ends; and a central area of the third radiator comprises a feed point, and the second feed part is coupled to the feed point.

13. The antenna structure according to claim 12, wherein a distance between the third radiator and the first radiator or the second radiator is less than or equal to 10 mm.

14. The antenna structure according to claim 12 or 13, wherein a length L4 of the third radiator in a first direction and a distance L5 between the first ground position and the second ground position in the first direction satisfy: L4×90%≤L5≤L4×110%, and the first direction is an extension direction of a length of the first radiator.

15. The antenna structure according to any one of claims 1 to 7, wherein a frequency of an electrical signal fed by the first feed part is at least partially the same as a frequency of an electrical signal fed by the second feed part.

16. An electronic device, comprising the antenna structure according to any one of claims 1 to 15, wherein the electronic device further comprises a side frame and a printed circuit board PCB, and the side frame comprises a conductive part; the side frame has a first position, a second position, and a second slit, the second slit is located between the first position and the second position, the first radiator of the antenna structure comprises at least a part of the side frame between the first position and the second slit, and the second radiator of the antenna structure comprises at least a part of the side frame between the second slit and the second position; and the PCB comprises the ground plane of the antenna structure.

17. The electronic device according to claim 16, wherein the electronic device further comprises a bracket, and at least a part of the third radiator of the antenna structure is located on a surface of the bracket.

18. The electronic device according to claim 16, wherein the electronic device further comprises a rear cover, and at least a part of the third radiator of the antenna structure is located on a surface of the rear cover.

19. The electronic device according to any one of claims 16 to 18, wherein a distance between the ground plane and a projection of the first radiator on a plane on which the ground plane is located or a projection of the second radiator on a plane on which the ground plane is located is less than 1 mm.

20. The electronic device according to any one of claims 16 to 19, wherein the first radiator and the second radiator are configured to generate a first resonance and a second resonance, wherein a resonant frequency band formed by the first resonance and the second resonance comprises a first frequency band; the third radiator is configured to generate a third resonance, wherein a resonant frequency band formed by the third resonance comprises the first frequency band; and an operating frequency band of the electronic device comprises the first frequency band.

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