Electronic Device

An electronic device includes an antenna structure having an antenna radiator, a first circuit, a first feeding element, and a second feeding element. The first circuit comprises feeding input ports configured to input electrical signals of the first feeding element and the second feeding element, and feeding output ports configured to feed processed electrical signals to the antenna radiator. The electrical signal of the first feeding element has a same phase on the feeding input ports. The electrical signal of the second feeding element has opposite phases on the feeding input ports.

This application claims priority to Chinese Patent Application No. 202011611722.2, filed with the China National Intellectual Property Administration on Dec. 30, 2020 and entitled “ELECTRONIC DEVICE”, and to Chinese Patent Application No. 202110296431.7, filed with the China National Intellectual Property Administration on Mar. 19, 2021 and entitled “ELECTRONIC DEVICE”, which are incorporated herein by reference in their entireties.

TECHNICAL FIELD

This application relates to the field of wireless communication, and in particular, to an electronic device.

BACKGROUND

With rapid development of wireless communication technologies, a second generation (second generation, 2G) mobile communication system mainly supports a call function, an electronic device is only a tool used by people to send and receive text messages and perform voice communication, and a wireless network access speed is very slow because data is transmitted through a voice channel. Currently, in addition to making a call, sending an SMS message, and taking a photo, the electronic device can also be used for listening to music online, watching an online movie and real-time video, and the like, covering various applications such as calling, film and television entertainment, and e-commerce in people's life. In these applications, a plurality of functional applications need to upload and download data through a wireless network. Therefore, high-speed data transmission is very important.

As people's demand for the high-speed data transmission increases, a multiple-input multiple-output (multiple-input multiple-output, MIMO) technology becomes particularly important. However, limited space inside the electronic device limits a frequency band that a MIMO antenna can cover and high performance. As a 5th generation (5th generation, 5G) wireless communication system requires more antennas, antennas share a radiator, so that space can be obviously multiplexed. In addition, an antenna design with high isolation and multi-band is becoming more important.

SUMMARY

This application provides an electronic device, and the electronic device may include an antenna structure. A first circuit of the antenna structure excites modes such as a half-wavelength mode, a one-time wavelength mode, and a three-half-wavelength mode of a CM mode, and may further excite modes such as a half-wavelength mode, a one-time wavelength mode, and a three-half-wavelength mode of a DM mode. The antenna structure can operate in the CM mode and the DM mode, and the antenna structure still has a plurality of resonances and a plurality of modes while having high isolation, which greatly improves practicability.

According to a first aspect, an electronic device is provided. The electronic device includes an antenna structure, where the antenna structure includes an antenna radiator, a first circuit, a first feeding element, and a second feeding element. The antenna radiator includes a first feeding point and a second feeding point, where the first feeding point and the second feeding point are respectively disposed on two sides of a virtual axis of the antenna radiator, the first feeding point and the second feeding point are symmetrical along the virtual axis, and electrical lengths of the antenna radiator on the two sides of the virtual axis are the same. The first circuit includes a first port, a second port, a third port, and a fourth port, where the first port and the second port are feeding output ports, the third port and the fourth port are feeding input ports, the feeding input ports are configured to input electrical signals of the first feeding element and the second feeding element, and the feeding output ports are configured to feed processed electrical signals to the antenna radiator. The first port is electrically connected to the first feeding point of the antenna radiator, and the second port is electrically connected to the second feeding point of the antenna radiator. The first feeding element is electrically connected to the third port and the fourth port, and the electrical signal of the first feeding element has a same phase on the third port and the fourth port. The second feeding element is electrically connected to the third port and the fourth port, and the electrical signal of the second feeding element has opposite phases on the third port and the fourth port.

According to the technical solution in this embodiment of this application, the first circuit is added to the antenna structure, so that a boundary condition corresponding to an (L-1/2) wavelength mode can be the same as a boundary condition corresponding to an M-time wavelength mode. A current corresponding to the (L-1/2) wavelength mode and a current corresponding to the M-time wavelength mode respectively go through different paths, to implement matching between the two modes, further to expand an operating bandwidth of the antenna structure. In addition, the first feeding element and the second feeding element may respectively excite the DM mode and the CM mode of the antenna structure. Therefore, in a same frequency band, good isolation can be maintained between resonant frequency bands respectively excited by the first feeding element and the second feeding element. The operating bandwidth of the antenna structure is further expanded.

With reference to the first aspect, in some implementations of the first aspect, when the first feeding element performs feeding, the electrical signal of the first feeding element passes through the first circuit, and is fed into the antenna radiator via the first port and the second port of the first circuit. When the second feeding element performs feeding, the electrical signal of the second feeding element passes through the first circuit, and is fed into the antenna radiator via the first port and the second port of the first circuit.

With reference to the first aspect, in some implementations of the first aspect, the antenna structure operates in at least one (L-1/2) wavelength mode and at least one M-time wavelength mode, where L and M are positive integers. An electrical signal corresponding to the at least one (L-1/2) wavelength mode in which the antenna structure operates and an electrical signal corresponding to the at least one M-time wavelength mode in which the antenna structure operates have different paths in the first circuit.

According to the technical solution in this embodiment of this application, because the first circuit is disposed, a current corresponding to the (L-1/2) wavelength mode and a current of the M-time wavelength mode go through different paths, to separately implement matching between the two modes.

With reference to the first aspect, in some implementations of the first aspect, the antenna radiator is symmetrical relative to the virtual axis.

According to the technical solution in this embodiment of this application, the virtual axis of the antenna radiator may be a virtual symmetry axis of the antenna radiator, and the antenna radiator is symmetrical to left and right along the symmetry axis. For the antenna structure, better symmetry of the structure indicates better isolation between resonant frequency bands respectively excited by the first feeding element and the second feeding element.

With reference to the first aspect, in some implementations of the first aspect, the electronic device further includes a first electric-conductor and a second electric-conductor. The antenna radiator includes a first radiator and a second radiator, and the first radiator and the second radiator are respectively disposed on the two sides of the virtual axis. A first end of the first radiator and a first end of the second radiator are opposite and do not contact each other, and form a first slot; a second end of the first radiator and a first end of the first electric-conductor form a second slot: and a second end of the second radiator and a first end of the second electric-conductor form a third slot.

With reference to the first aspect, in some implementations of the first aspect, the first electric-conductor and the second electric-conductor are a part of a ground, or both the first end of the first electric-conductor and the first end of the second electric-conductor are electrically connected to the ground.

According to the technical solution in this embodiment of this application, an example in which the first electric-conductor and the second electric-conductor are only a part of the ground is used. This is not limited in this application. In another embodiment of this application, the first electric-conductor and the second electric-conductor may be respectively electrically connected to the ground at first ends of the first electric-conductor and the second electric-conductor. For example, the first electric-conductor and the second electric-conductor are used as radiators of another antenna structure. It should be understood that, an electrical connection of the first end to the ground includes an electrical connection to the ground at the end, and also includes an electrical connection to the ground at a ground point on an electric-conductor near the end.

With reference to the first aspect, in some implementations of the first aspect, the first circuit includes a first inductor, a second inductor, a third inductor, and a fourth inductor. The first inductor is connected in series between the first port and the third port; the third inductor is connected in series between the second port and the fourth port: the second inductor is connected in parallel between the first inductor and the first port and is grounded; and the fourth inductor is connected in parallel between the third inductor and the second port and is grounded.

According to the technical solution in this embodiment of this application, the inductors are connected in parallel and connected in series in the first circuit, and the current corresponding to the (L-1/2) wavelength mode and the current of the M-time wavelength mode go through different paths, to separately implement matching between the two modes.

With reference to the first aspect, in some implementations of the first aspect, an inductance value of the first inductor is the same as an inductance value of the third inductor, and an inductance value of the second inductor is the same as an inductance value of the fourth inductor.

According to the technical solution in this embodiment of this application, an electronic component disposed between the first port and the third port and an electronic component disposed between the second port and the fourth port are symmetrical to each other.

With reference to the first aspect, in some implementations of the first aspect, the antenna structure generates a first resonance via the antenna radiator, the second inductor, the fourth inductor, the first feeding element, and the second feeding element. The antenna structure generates a second resonance via the antenna radiator, the first inductor, the third inductor, the first feeding element, and the second feeding element.

With reference to the first aspect, in some implementations of the first aspect, the first resonance corresponds to an (L-1/2) wavelength mode of the antenna structure. The second resonance corresponds to an M-time wavelength mode of the antenna structure, where L and M are positive integers.

According to the technical solution in this embodiment of this application, a boundary condition corresponding to the (L-1/2) wavelength mode is the same as a boundary condition corresponding to the M-time wavelength mode, and may be respectively matched with the (L-1/2) wavelength mode and the M-time wavelength mode. A same boundary condition may be considered as a same impedance corresponding to the antenna modes. Therefore, matching of the two modes can be implemented.

With reference to the first aspect, in some implementations of the first aspect, the electronic device further includes a first electric-conductor and a second electric-conductor. The antenna radiator is a complete metal piece, where one end of the antenna radiator and a first end of the first electric-conductor form a first slot, and the other end of the antenna radiator and the first end of the second electric-conductor form a second slot.

With reference to the first aspect, in some implementations of the first aspect, and the electronic device further includes a ground, the first electric-conductor and the second electric-conductor are a part of the ground, or both the first end of the first electric-conductor and the first end of the second electric-conductor are electrically connected to the ground.

In this application, an example in which the first electric-conductor and the second electric-conductor are only a part of the ground is used. This is not limited in this application. In another embodiment of this application, the first electric-conductor and the second electric-conductor may be respectively electrically connected to the ground at first ends of the first electric-conductor and the second electric-conductor. For example, the first electric-conductor and the second electric-conductor are used as radiators of another antenna structure. It should be understood that, an electrical connection of the first end to the ground includes an electrical connection to the ground at the end, and also includes an electrical connection to the ground at a ground point on an electric-conductor near the end.

With reference to the first aspect, in some implementations of the first aspect, the antenna radiator is a complete metal piece, and the antenna radiator is a wire antenna radiator.

With reference to the first aspect, in some implementations of the first aspect, the electronic device further includes a ground. The antenna radiator includes a first radiator and a second radiator, and the first radiator and the second radiator are respectively disposed on the two sides of the virtual axis. A first end of the first radiator and a first end of the second radiator are opposite and do not contact each other, and form a first slot; a second end of the first radiator is electrically connected to the ground; and a second end of the second radiator is electrically connected to the ground.

With reference to the first aspect, in some implementations of the first aspect, the first circuit includes a first capacitor, a second capacitor, and a third capacitor. The first capacitor is connected in series between the first port and the third port: the second capacitor is connected in series between the second port and the fourth port: and a first end of the third capacitor is disposed between the first capacitor and the first port, and a second end of the third capacitor is disposed between the second capacitor and the second port.

According to the technical solution in this embodiment of this application, the capacitors are connected in parallel and connected in series in the first circuit, and the current corresponding to the (L-1/2) wavelength mode and the current of the M-time wavelength mode go through different paths, to separately implement matching between the two modes.

With reference to the first aspect, in some implementations of the first aspect, capacitance values of the first capacitor and the second capacitor are the same.

According to the technical solution in this embodiment of this application, an electronic component disposed between the first port and the third port and an electronic component disposed between the second port and the fourth port are symmetrical to each other.

With reference to the first aspect, in some implementations of the first aspect, the antenna structure generates a first resonance via the antenna radiator, the first capacitor, the second capacitor, the first feeding element, and the second feeding element. The antenna structure generates a second resonance via the antenna radiator, the third capacitor, the first feeding element, and the second feeding element.

With reference to the first aspect, in some implementations of the first aspect, the first resonance corresponds to an (L-1/2) wavelength mode of the antenna structure. The second resonance corresponds to an M-time wavelength mode of the antenna structure, where L and M are positive integers.

According to the technical solution in this embodiment of this application, a boundary condition corresponding to the (L-1/2) wavelength mode is the same as a boundary condition corresponding to the M-time wavelength mode, and may be respectively matched with the (L-1/2) wavelength mode and the M-time wavelength mode. A same boundary condition may be considered as a same impedance corresponding to the two modes. Therefore, matching of the two modes can be implemented.

With reference to the first aspect, in some implementations of the first aspect, the electronic device further includes a 180° directional coupler. The 180° directional coupler is disposed between the first circuit and the first feeding element and the second feeding element. The 180° directional coupler is configured to enable the electrical signal of the first feeding element to have a same phase at the third port and the fourth port of the first circuit. The 180° directional coupler is further configured to enable the electrical signal of the second feeding element to have opposite phases at the third port and the fourth port of the first circuit.

According to the technical solution in this embodiment of this application, a 180° directional coupler240is merely a technical means for implementing that a phase of an electrical signal of a feeding element between a third port123and a fourth port124are the same or opposite, and may also be implemented via another technical means in actual production or design, for example, a balun, a 180° coupler, or a combination of a 90° coupler and a phase shift network. This is not limited in this application.

With reference to the first aspect, in some implementations of the first aspect, the electronic device further includes a first matching network and a second matching network. The first matching network is disposed between the first feeding element and the 180° directional coupler, and is configured to match an impedance of the first feeding element. The second matching network is disposed between the second feeding element and the 180° directional coupler, and is configured to match an impedance of the second feeding element.

According to the technical solution in this embodiment of this application, the first matching network is configured to match the impedance of the first feeding element and may match the electrical signal in the first feeding element with a characteristic of a radiator, so that transmission loss and distortion of the electrical signal are minimized. The second matching network is configured to match the impedance of the second feeding element, and may match the electrical signal in the second feeding element with a characteristic of a radiator, so that transmission loss and distortion of the electrical signal are minimized.

According to a second aspect, an electronic device is provided. The electronic device includes an antenna structure, where the antenna structure includes an antenna radiator, a first circuit, and a feeding element. The antenna radiator includes a first feeding point and a second feeding point, where the first feeding point and the second feeding point are respectively disposed on two sides of a virtual axis of the antenna radiator, the first feeding point and the second feeding point are symmetrical along the virtual axis, and electrical lengths of the antenna radiator on the two sides of the virtual axis are the same. The first circuit includes a first port, a second port, a third port, and a fourth port, where the first port and the second port are feeding output ports, the third port and the fourth port are feeding input ports, the feeding input ports are configured to input electrical signals of the feeding elements, and the feeding output ports are configured to feed processed electrical signals to the antenna radiator. The first port is electrically connected to the first feeding point of the antenna radiator, and the second port is electrically connected to the second feeding point of the antenna radiator. The feeding element is electrically connected to the third port and the fourth port, and the electrical signal of the feeding element has a same phase on the third port and the fourth port; or the electrical signal of the feeding element has opposite phases at the third port and the fourth port.

With reference to the second aspect, in some implementations of the second aspect, the antenna structure operates in at least one (L-1/2) wavelength mode and at least one M-time wavelength mode, where L and M are positive integers. An electrical signal corresponding to the at least one (L-1/2) wavelength mode in which the antenna structure operates and an electrical signal corresponding to the at least one M-time wavelength mode in which the antenna structure operates have different paths in the first circuit.

With reference to the second aspect, in some implementations of the second aspect, the antenna radiator is symmetrical relative to the virtual axis.

With reference to the second aspect, in some implementations of the second aspect, the electronic device further includes a first electric-conductor and a second electric-conductor. The antenna radiator includes a first radiator and a second radiator, and the first radiator and the second radiator are symmetrical along the virtual axis. A first end of the first radiator and a first end of the second radiator are opposite and do not contact each other, and form a first slot; a second end of the first radiator and a first end of the first electric-conductor form a second slot; and a second end of the second radiator and a first end of the second electric-conductor form a third slot.

With reference to the second aspect, in some implementations of the second aspect, and the electronic device further includes a ground, the first electric-conductor and the second electric-conductor are a part of the ground, or both the first end of the first electric-conductor and the first end of the second electric-conductor are electrically connected to the ground.

With reference to the second aspect, in some implementations of the second aspect, the first circuit includes a first inductor, a second inductor, a third inductor, and a fourth inductor. The first inductor is connected in series between the first port and the third port; the third inductor is connected in series between the second port and the fourth port: the second inductor is connected in parallel between the first inductor and the first port and is grounded; and the fourth inductor is connected in parallel between the third inductor and the second port and is grounded.

With reference to the second aspect, in some implementations of the second aspect, an inductance value of the first inductor is the same as an inductance value of the third inductor, and an inductance value of the second inductor is the same as an inductance value of the fourth inductor.

With reference to the second aspect, in some implementations of the second aspect, the antenna structure generates a first resonance via the antenna radiator, the second inductor, the fourth inductor, and the feeding element. The antenna structure generates a second resonance via the antenna radiator, the first inductor, the third inductor, and the feeding element.

With reference to the second aspect, in some implementations of the second aspect, the first resonance corresponds to an (L-1/2) wavelength mode of the antenna structure. The second resonance corresponds to an M-time wavelength mode of the antenna structure, where L and M are positive integers.

With reference to the second aspect, in some implementations of the second aspect, the electronic device further includes a ground. The antenna radiator includes a first radiator and a second radiator, and the first radiator and the second radiator are respectively disposed on the two sides of the virtual axis. A first end of the first radiator and a first end of the second radiator are opposite and do not contact each other, and form a first slot; a second end of the first radiator is electrically connected to the ground; and a second end of the second radiator is electrically connected to the ground.

With reference to the second aspect, in some implementations of the second aspect, the first circuit includes a first capacitor, a second capacitor, and a third capacitor. The first capacitor is connected in series between the first port and the third port; the second capacitor is connected in series between the second port and the fourth port: and a first end of the third capacitor is disposed between the first capacitor and the first port, and a second end of the third capacitor is disposed between the second capacitor and the second port.

With reference to the second aspect, in some implementations of the second aspect, capacitance values of the first capacitor and the second capacitor are the same.

With reference to the second aspect, in some implementations of the second aspect, the antenna structure generates a first resonance via the antenna radiator, the first capacitor, the second capacitor, and the feeding element. The antenna structure generates a second resonance via the antenna radiator, the third capacitor, and the feeding element.

With reference to the second aspect, in some implementations of the second aspect, the first resonance corresponds to an (L-1/2) wavelength mode of the antenna structure. The second resonance corresponds to an M-time wavelength mode of the antenna structure, where L and M are positive integers.

With reference to the second aspect, in some implementations of the second aspect, the electronic device further includes a 180° directional coupler. The 180° directional coupler is disposed between the first circuit and the first feeding element and the second feeding element. The 180° directional coupler is configured to enable the electrical signal of the first feeding element to have a same phase at the third port and the fourth port of the first circuit. The 180° directional coupler is further configured to enable the electrical signal of the second feeding element to have opposite phases at the third port and the fourth port of the first circuit.

DESCRIPTION OF EMBODIMENTS

The following describes the technical solutions in this application with reference to the accompanying drawings.

It should be understood that, in this application, “electrical connection” may be understood that components contact physically and conduct electrically. It may also be understood as a form in which different components in a line structure are connected through physical lines that can transmit an electrical signal, such as a printed circuit board (printed circuit board, PCB) copper foil or a conducting wire. A “communication connection” may refer to an electrical signal transmission, including a wireless communication connection and a wired communication connection. The wireless communication connection does not require a physical medium and does not belong to a connection relationship that defines a construction of a product. Both “connection” and “interconnection” may mean a mechanical connection relationship or a physical connection relationship. For example, A-B connection or A-B interconnection may mean that a fastened component (such as a screw, a bolt, a rivet, etc.) exists between A and B; or A and B are in contact with each other and are difficult to be separated.

The technical solutions provided in this application are applicable to an electronic device that uses one or more of the following communication technologies: a Bluetooth (Bluetooth, BT) communication technology, a global positioning system (global positioning system, GPS) communication technology, a wireless fidelity (wireless fidelity, Wi-Fi) communication technology, a global system for mobile communications (global system for mobile communications. GSM) communication technology, a wideband code division multiple access (wideband code division multiple access, WCDMA) communication technology, a long term evolution (long term evolution, LTE) communication technology, a 5G communication technology, and other future communication technologies. The electronic device in embodiments of this application may be a mobile phone, a tablet computer, a laptop computer, a smart band, a smart watch, a smart helmet, smart glasses, or the like. Alternatively, the electronic device may be a cellular phone, a cordless phone, a session initiation protocol (session initiation protocol, SIP) phone, a wireless local loop (wireless local loop, WLL) station, a personal digital assistant (personal digital assistant, PDA), a handheld device with a wireless communication function, a computing device or another processing device connected to a wireless modem, a vehicle-mounted device, an electronic device in a 5G network, an electronic device in a future evolved public land mobile network (public land mobile network, PLMN), or the like. This is not limited in this embodiment of this application.

FIG.1shows an example of an internal environment of an electronic device according to this application. An example in which the electronic device is a mobile phone is used for description.

As shown inFIG.1, an electronic device10may include a cover glass (cover glass)13, a display (display)15, a printed circuit board (printed circuit board, PCB)17, a housing (housing)19, and a rear cover (rear cover)21.

The cover glass13may be disposed close to the display15, and may be mainly configured to protect the display15from dust.

In an embodiment, the display15may be a liquid crystal display (liquid crystal display, LCD), a light-emitting diode (light-emitting diode, LED), an organic light-emitting diode (organic light-emitting diode, OLED), or the like. This is not limited in this application.

The printed circuit board PCB17may be a flame-resistant material (FR-4) dielectric board, or may be a Rogers (Rogers) dielectric board, or may be a dielectric board mixing Rogers and FR-4, or the like. Here, FR-4 is a grade designation for a flame-resistant material the Rogers dielectric board is a high-frequency board. A metal layer may be disposed on a side of the printed circuit board PCB17close to the housing19, and the metal layer may be formed by etching metal on a surface of the PCB17. The metal layer may be used for grounding an electronic component carried on the printed circuit board PCB17, to prevent an electric shock of a user or damage to a device. The metal layer may be referred to as a PCB ground. Not limited to the PCB ground, the electronic device10may alternatively have another ground for grounding, for example, a metal middle frame or another metal plane in the electronic device. In addition, a plurality of electronic components are disposed on the PCB17, and the plurality of electronic components include one or more of a processor, a power management module, a memory, a sensor, a SIM card interface, and the like. Metal is also disposed inside or on surfaces of these electronic components.

The electronic device10may alternatively include a battery, which is not shown herein. The battery may be disposed in the housing19, the battery may divide the PCB17into a main board and a sub-board, the main board may be disposed between a frame11of the housing19and an upper edge of the battery, and the sub-board may be disposed between the housing19and a lower edge of the battery. A metal layer is also disposed inside or on the surface of the battery.

The housing19is mainly used to support the electronic device10. The housing19may include the frame11, and the frame11may be formed of a conductive material such as metal. The frame11may extend around peripheries of the electronic device10and the display15. The frame11may specifically surround four side edges of the display15, to help fasten the display15. In an implementation, the frame11made of a metal material may be directly used as a metal frame of the electronic device10to form an appearance of the metal frame, and is applicable to a metal industrial design (industrial design, ID). In another implementation, an outer surface of the frame11may alternatively be a non-metal material, for example, a plastic frame, to form an appearance of the non-metal frame, and is applicable to a non-metal ID.

The rear cover21may be a rear cover made of a metal material, or may be a rear cover made of a non-conductive material, such as a non-metallic rear cover: a glass rear cover or a plastic rear cover.

FIG.1schematically shows only some components included in the electronic device10. Actual shapes, actual sizes, and actual structures of these components are not limited inFIG.1. In addition, the electronic device10may alternatively include components such as a camera and a sensor.

First, this application relates to four antenna modes as described with reference toFIG.2toFIG.5.FIG.2is a schematic diagram of a common-mode structure of a wire antenna and distribution of corresponding currents and electric fields according to this application.FIG.3is a schematic diagram of another differential-mode structure of a wire antenna and distribution of corresponding currents and electric fields according to this application.FIG.4is a schematic 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.5is a schematic diagram of another differential-mode structure of a slot antenna and distribution of corresponding currents, electric fields and magnetic currents according to this application.

1. Common Mode (Common Mode, CM) of a Wire Antenna

Herein. (a) inFIG.2shows a case in which a radiator of a wire antenna40is grounded (for example, connected to a ground, which may be a PCB) through a feeding line42. The wire antenna40is connected to a feeding element (not shown) at a middle position41, and uses a symmetrical feed (symmetrical feed). The feeding element may be connected to the middle position41of the wire antenna40through the feeding line42. It should be understood that the symmetrical feed may be understood as that one end of the feeding element is connected to the radiator and the other end is grounded. A connection point (feeding point) between the feeding element and the radiator is located in a center of the radiator, and the center of the radiator may be, for example, a midpoint of a collective structure, or a midpoint of an electrical length (or an area within a specific range near the midpoint).

The middle position41of the wire antenna40, for example, the middle position41, may be a geometric center of the wire antenna, or the midpoint of the electrical length of the radiator, for example, a connection between the feeding line42and the wire antenna40covers the middle position41.

Herein, (b) inFIG.2shows current and electric field distribution of the wire antenna40. As shown in (b) inFIG.2, the currents are symmetrically distributed on both sides of the middle position41, for example, reversely distributed. The electric fields are distributed in the same direction on both sides of the middle position41. As shown in (b) inFIG.2, the currents at the feeding line42are distributed in the same direction. Based on the co-directional distribution of currents at the feeding line42, such a feed as shown in (a) inFIG.2may be referred to as a CM feed of a wire antenna. Based on the symmetrical distribution of the currents at on two sides of the connection between the radiator and the feeding line42, the wire antenna mode shown in (b) inFIG.2may be referred to as a CM mode of the wire antenna (or may be referred to as a CM wire antenna for short). Currents and electric fields shown in (b) inFIG.2may be referred to as currents and electric fields of the CM mode of the wire antenna, respectively.

The currents and electric fields of the CM mode of the wire antenna are generated by two branches (for example, two horizontal branches) on both sides of the middle position41of the wire antenna40as antennas operating in a quarter-wavelength mode. The current is strong at the middle position41of the wire antenna40and weak at two ends of a wire antenna101. The electric field is weak at the middle position41of the wire antenna40and strong at two ends of the wire antenna40.

2. Differential Mode (Differential Mode, DM) of the Wire Antenna

Herein, (a) inFIG.3shows a case in which two radiators of a wire antenna50are grounded (for example, connected to a ground, which may be a PCB) through a feeding line52. The wire antenna50connects a feeding element at a middle position51between the two radiators and uses an anti-symmetrical feed (anti-symmetrical feed). One end of the feeding element is connected to one of the radiators through the feeding line52, and the other end of the feeding element is connected to the other of the radiators through the feeding line52. The middle position51may be a geometric center of the wire antenna, or a slot between the radiators.

It should be understood that the anti-symmetrical feed may be understood as that positive and negative poles of the feeding element are respectively connected to two ends of the radiator. Signals output from the positive and negative poles of the feeding element have the same amplitude but opposite phases, for example, a phase difference is 180°±10°.

(b) inFIG.3shows current and electric field distribution of the wire antenna50. As shown in (b) inFIG.3, the currents are asymmetrically distributed on two sides of the middle position51of the wire antenna50, for example, distributed in the same direction. The electric fields are distributed reversely on both sides of the middle position51. As shown in (b) inFIG.3, the currents at the feeding line52are distributed reversely. Based on the reverse distribution of the currents at the feeding line52, such a feed as shown in (a) inFIG.3may be referred to as a DM feed of a wire antenna. Based on the asymmetrical distribution (for example, the co-directional distribution) of the currents at both sides of the connection between the radiator and the feeding line52, the wire antenna mode shown in (b) inFIG.3may be referred to as a DM mode of the wire antenna (or may be referred to as a DM wire antenna for short). Currents and electric fields shown in (b) inFIG.3may be referred to as currents and electric fields in the DM mode of the wire antenna, respectively.

The currents and electric fields in the DM mode of the wire antenna are generated by the entire wire antenna50as an antenna operating in a half-wavelength mode. The current is strong at the middle position51of the wire antenna50and weak at two ends of the wire antenna50. The electric field is weak at the middle position51of the wire antenna50and strong at two ends of the wire antenna50.

It should be understood that the radiator of the wire antenna may be understood as a metal mechanical part that generates radiation, and a quantity of the radiator may be one, as shown inFIG.2, or may be two, as shown inFIG.3, and may be adjusted according to an actual design or production requirement. For example, for the CM mode of the wire antenna, as shown inFIG.3, two radiators may also be used, two ends of the two radiators are oppositely disposed and a slot is spaced apart, and two ends that are close to each other use a symmetrical feed manner. For example, an effect similar to that of the antenna structure shown inFIG.2may also be obtained by separately feeding a same feed signal into two ends that are close to each other of the two radiators. Correspondingly, for the DM mode of the wire antenna, as shown inFIG.2, one radiator may also be used, and two feeding points are disposed in the middle position of the radiator, and an anti-symmetrical feed manner is used. For example, an effect similar to that of the antenna structure shown inFIG.3may also be obtained if signals of a same amplitude and opposite phases are respectively fed into two symmetrical feeding points on the radiator.

3. CM Mode of the Slot Antenna

A slot antenna60shown in (a) inFIG.4may be formed by a hollowed-out groove or a slot61in a radiator of the slot antenna, or may be formed by a radiator of the slot antenna and a ground (for example, a ground, which may be a PCB) enclosing the groove or the slot61. The slot61may be formed by providing a slot on the ground. An opening62is disposed on one side of the slot61, and the opening62may be specifically disposed in a middle position of the side. The middle position of the side of the slot61may 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 opening62on the radiator covers the middle position of the side. A feeding element may be connected at the opening62, and anti-symmetrical feed is used. It should be understood that the anti-symmetrical feed may be understood as that positive and negative poles of the feeding element are respectively connected to two ends of the radiator. Signals output from the positive and negative poles of the feeding element have the same amplitude but opposite phases, for example, a phase difference is 180°±10°.

Herein, (b) inFIG.4shows current, electric field, and magnetic current distribution of the slot antenna60. As shown in (b) inFIG.4, currents are distributed in a same direction around the slot61on a conductor (for example, a ground and/or a radiator60) around the slot61, and the electric fields are distributed reversely on two sides of a middle position of the slot61. The magnetic currents are distributed reversely on both sides of the middle position of the slot61. As shown in (b) inFIG.4, electric fields are in the same direction at the opening62(for example, a feeding position), and magnetic currents are in the same direction at the opening62(for example, the feeding position). Based on co-directional magnetic currents at the opening62(the feeding position), the feed shown in (a) inFIG.4may be referred to as CM feed for the slot antenna. On the basis that the currents are distributed asymmetrically (for example, in the same direction) on the radiators on both sides of the opening62, or on the basis that the currents are distributed in the same direction around the slot61on the conductor around the slot61, the slot antenna mode shown in (b) inFIG.4may be referred to as a CM mode of the slot antenna (which may also be referred to as a CM slot antenna or a CM slot antenna for short). The electric field, the current, and the magnetic current distribution shown in (b) inFIG.4may be respectively referred to as an electric field, a current, and a magnetic current distribution of a CM mode of the slot antenna.

The current and the electric field of the CM mode of the slot antenna are generated via slot antenna bodies on both sides of the middle position of the slot antenna60as antennas operating in a half-wavelength mode. The magnetic field is weak at the middle position of the slot antenna60, and strong at two ends of the slot antenna60. The electric field is strong at the middle position of the slot antenna60, and weak at two ends of the slot antenna60.

4. DM Mode of the Slot Antenna

A slot antenna70shown in (a) inFIG.5may be formed by a hollowed-out groove or a slot72in a radiator of the slot antenna, or may be formed by a radiator of the slot antenna and a ground (for example, a ground, which may be a PCB) enclosing the groove or the slot72. The slot72may be formed by providing a slot on the ground. A middle position71of the slot72is connected to a feeding element, and symmetrical feed is used. It should be understood that the symmetrical feed may be understood as that one end of the feeding element is connected to the radiator and the other end is grounded. A connection point (feeding point) between the feeding element and the radiator is located in a center of the radiator, and the center of the radiator may be, for example, a midpoint of a collective structure, or a midpoint of an electrical length (or an area within a specific range near the midpoint). A middle position of one side of the slot72is connected to a positive electrode of the feeding element, and a middle position of the other side of the slot72is connected to a negative electrode of the feeding element. The middle position of the side of the slot72may be, for example, the middle position of the slot antenna60/the middle position of the ground, for example, a geometric midpoint of the slot antenna, or a midpoint of an electrical length of the radiator. For example, a connection between the feeding element and the radiator covers the middle position51of the side.

Herein, (b) inFIG.5shows current, electric field, and magnetic current distribution of the slot antenna70. As shown in (b) inFIG.5, on a conductor (such as the ground and/or the radiator60) around the slot72, currents are distributed around the slot72, and are distributed reversely on both sides of a middle position of the slot72, and electric fields are distributed in a same direction on both sides of the middle position71. The magnetic currents are distributed in the same direction on both sides of the middle position71. Magnetic currents are reversely distributed at the feeding element (not shown). Based on reverse distribution of the magnetic currents at the feeding element, the feed shown in (a) inFIG.5may be referred to as DM feed for the slot antenna. On the basis that the currents are symmetrically distributed (for example, reversely distributed) on two sides of a connection between the feeding element and the radiator, or on the basis that the currents are symmetrically distributed (for example, reversely distributed) around the slot71. The slot antenna mode shown in (b) inFIG.5may be referred to as a DM mode of the slot antenna (which may also be referred to as a DM slot antenna or a DM slot antenna for short). The electric field, the current, and the magnetic current distribution shown in (b) inFIG.5may be referred to as an electric field, a current, and a magnetic current of a DM mode of the slot antenna.

The currents and electric fields of the DM mode of the slot antenna are generated by the entire slot antenna70as an antenna operating in a one-time wavelength mode. The current is weak at the middle position of the slot antenna70, and strong at two ends of the slot antenna70. The electric field is strong at the middle position of the slot antenna70, and weak at two ends of the slot antenna70.

In the antenna field, an antenna operating in the CM mode and an antenna operating in the DM mode generally have high isolation. In addition, frequency bands of the antennas operating in the CM mode and operating in the DM mode are usually single-mode resonance, and it is difficult to cover a plurality of frequency bands required for communication. In particular, space left by an electronic device for an antenna structure is decreasing day by day. For a MIMO system, a single antenna structure is required to implement coverage of the plurality of frequency bands. Therefore, an antenna with multi-mode resonance and high isolation is of high research and practical value.

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 a ground) that generates radiation, and may include an opening, as shown inFIG.4, or may be a complete ring, as shown inFIG.5, and may be adjusted according to an actual design or production requirement. For example, for the CM mode of the slot antenna, as shown inFIG.5, a complete ring radiator may also be used, and two feeding points are disposed in a middle position of the radiator on one side of the slot61, 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 an effect similar to that of the antenna structure shown inFIG.4can also be obtained. Correspondingly, for the DM mode of the slot antenna, as shown inFIG.4, a radiator including an opening may also be used, and a symmetrical feed manner is used at two ends of the opening position. For example, a same feed signal is respectively fed into two ends of the radiator on two sides of the opening. An effect similar to that of the antenna structure shown inFIG.5may also be obtained.

This application provides an electronic device, and the electronic device may include an antenna structure. A first circuit of the antenna structure excites modes such as a half-wavelength mode, a one-time wavelength mode, and a three-half-wavelength mode of a CM mode, and may further excite modes such as a half-wavelength mode, a one-time wavelength mode, and a three-half-wavelength mode of a DM mode. The antenna structure can operate in the CM mode and the DM mode, and the antenna structure still has a plurality of resonances and a plurality of modes while having high isolation, which greatly improves practicability. In addition, because an antenna operating in the CM mode and an antenna operating in the DM mode share a same radiator, a volume of the antenna structure can also be effectively reduced.

FIG.6is a distribution diagram of current intensity points of a slot antenna according to an embodiment of this application.

As shown in (a) inFIG.6, current distribution of a slot antenna operating in a half-wavelength mode is shown. The slot antenna uses anti-symmetrical feed, and the current intensity points of the slot antenna are located in an area in which the feeding element is located. A radiator itself has a plurality of modes that can be excited, and a corresponding mode can be excited as long as an input impedance of the radiator is consistent with an impedance of an excitation source. Therefore, when the excitation source uses the input impedance corresponding to the current distribution shown in (a) inFIG.6, the half-wavelength mode of the slot antenna can be excited, and an (N-1/2) wavelength mode of the slot antenna can be excited, where N is a positive integer. For a slot antenna or a wire antenna, the (N-1/2) wavelength mode of the slot antenna may be considered as follows: A wavelength corresponding to resonance generated by the antenna structure in this mode is approximately (N-1/2) times of an electrical length of a radiator in the antenna structure. It should be understood that approximately (N-1/2) times means that due to an operating environment of the antenna structure and settings of a matching circuit and the like, a relationship between the wavelength corresponding to the resonance generated in the (N-1/2) wavelength mode and the electrical length of the radiator may not be strictly (N-1/2) times, but a specific error is allowed. In addition, the antenna structure has (N-1/2)/(1/2) current zero points in the (N-1/2) wavelength mode. This is specifically described inFIG.14below, and details are not described herein again.

It should be understood that anti-symmetrical feed may be understood as that positive and negative poles of the feeding element are respectively connected to two ends of the radiator. Signals output from the positive and negative poles of the feeding element have the same amplitude but opposite phases, for example, a phase difference is 180°±10°.

As shown in (b) inFIG.6, current distribution of a slot antenna operating in a one-time wavelength mode is shown. The slot antenna uses symmetrical feed, and current intensity points of the slot antenna are located on two sides of the slot. When the excitation source uses the input impedance corresponding to the current distribution shown in (b) inFIG.6, the one-time wavelength mode of the slot antenna can be excited, and N-time wavelength mode of the slot antenna can be excited, where N is a positive integer. For a slot antenna or a wire antenna, the N-time wavelength mode of the slot antenna may be considered as follows: A wavelength corresponding to resonance generated by the antenna structure in this mode is approximately N times of an electrical length of a radiator in the antenna structure. It should be understood that approximately N times means that due to an operating environment of the antenna structure and settings of a matching circuit and the like, a relationship between the wavelength corresponding to the resonance generated in the N-time wavelength mode and the electrical length of the radiator may not be strictly N times, but a specific error is allowed. In addition, the antenna structure has N/(1/2) current zero points in the N-time wavelength mode. This is specifically described inFIG.14below, and details are not described herein again.

It should be understood that the symmetrical feed may be understood as that one end of the feeding element is connected to the radiator and the other end is grounded. A connection point (feeding point) between the feeding element and the radiator is located in a center of the radiator, and the center of the radiator may be, for example, a midpoint of a collective structure, or a midpoint of an electrical length (or an area within a specific range near the midpoint).

Therefore, for the slot antenna shown in (a) inFIG.6, the N-time wavelength mode of the slot antenna is not excited. When the slot antenna operates in the half-wavelength mode, a current intensity point corresponding to the one-time wavelength mode is a current weak point, and vice versa. For an impedance of the N-time wavelength mode and an impedance of the (N-1/2) wavelength mode, the (N-1/2) wavelength mode corresponds to a high impedance, and the N-time wavelength mode corresponds to a low impedance. As a result, it is difficult to match the two modes at the same time, or the two modes cannot be excited at the same time.

FIG.7is a schematic diagram of a structure of a slot antenna according to an embodiment of this application.

As shown inFIG.7, a circuit20is added between a feeding element and a radiator, so that a current corresponding to an (N-1/2) wavelength mode and a current corresponding to an N-time wavelength mode separately go different paths, to implement matching between the two modes. The circuit20may be a filter circuit, a matching circuit, a circuit in another form, or a combination of these circuits. This is not limited in this application.

As shown inFIG.7, the slot antenna uses anti-symmetrical feed. From an input impedance of the anti-symmetrical feed, an impedance of a half-wavelength mode is a high impedance, and an impedance of a one-time wavelength mode is a low impedance. The impedance of the half-wavelength mode is often opposite to that of the one-time wavelength mode. It should be understood that, for the half-wavelength mode and the one-time wavelength mode, boundary conditions of the two modes are different (opposite impedances). To ensure that the half-wavelength mode and the one-time wavelength mode are excited in a same antenna, it is desirable for the circuit20to make the boundary conditions of the half-wavelength mode and the one-time wavelength mode the same, for example, both are high impedance or both are low impedance. A series capacitor21may match the half-wavelength mode, so that a current in this mode goes through the capacitor21connected in series by the feeding element, and a parallel capacitor22may match the one-time wavelength mode, so that a current in this mode goes through the capacitor22connected in parallel by the feeding element. For example, the radiator of the slot antenna, the feeding element, and the series capacitor21generate a first resonance, which corresponds to the half-wavelength mode. In this mode, a current has a zero point. For another example, the radiator of the slot antenna, the feeding element, and the parallel capacitor22generate a second resonance, which corresponds to the one-time wavelength mode. In this mode, a current has two zero points. It should be understood that the foregoing capacitors match corresponding modes to change current paths of electrical signals in the modes corresponding to the capacitors. Therefore, the circuit20may match a plurality of modes of the slot antenna, to implement multi-resonance, and to expand a bandwidth of the antenna.

It should be understood that the circuit20shown inFIG.7is merely an example. The circuit20is configured to make a current path of the half-wavelength mode different from a current path of the one-time wavelength mode, so that boundary conditions corresponding to the half-wavelength mode and the one-time wavelength mode are the same. In addition, an electronic component may also be added on the circuit20, and an equivalent electrical length of the radiator may be changed, to implement fine-tuning of a resonance frequency, as shown inFIG.8. This is not limited in this application, and may be adjusted according to actual production or design.

FIG.9andFIG.10are schematic diagrams of simulation results of the antenna structure shown inFIG.7.FIG.9is an S-parameter simulation result diagram of the antenna structure shown inFIG.7.FIG.10is a smith (smith) simulation result diagram of the antenna structure shown inFIG.7.

As shown inFIG.9, the antenna structure generates resonances at frequencies 2.17 GHz and 3.93 GHz respectively, and the resonances are respectively corresponding to a half-wavelength mode and a one-time wavelength mode of the antenna structure, so that the antenna structure can generate a plurality of resonances.

As shown inFIG.10, good matching can be achieved between the half-wavelength mode and the one-time wavelength mode of the antenna structure due to disposing of a circuit.

It should be understood that, for an antenna structure in which no circuit is added, a current path of a half-wavelength mode of the antenna structure is a capacitor connected in series, a feeding position is a large electric field, a current path of a one-time wavelength mode is a capacitor connected in parallel, and a feeding position is a large current. According to the circuit provided in this embodiment of this application, a boundary condition corresponding to the (N-1/2) wavelength mode and/or the N-time wavelength mode is changed, so that the boundary conditions of the two modes are the same, for example, both are high impedance, or both are low impedance, and both can be excited. Therefore, according to the circuit provided in this application, the antenna structure can match the half-wavelength mode and the one-time wavelength mode, to generate a plurality of resonances.

FIG.11is a schematic diagram of an antenna structure according to an embodiment of this application.

As shown inFIG.11, the antenna structure may include an antenna radiator110, a first circuit120, and a feeding element130.

Electrical lengths of antenna radiators on left and right of a virtual axis (which referred to as a “virtual axis” below) are the same. It should be understood that, in engineering application, antenna structures may not be completely the same due to internal layout of an electronic device. It may be considered that an error range of the electrical lengths of the antenna radiators on the left and right of the axis is within one-sixteenth of an operating wavelength, and “same electrical lengths” in this application is met. The antenna radiator110may include a first feeding point111and a second feeding point112. The first feeding point111and the second feeding point112are respectively disposed on two sides of the axis, and the first feeding point111and the second feeding point112are symmetrical along the axis. The first circuit120includes a first port121, a second port122, a third port123, and a fourth port124. The first port121and the second port122are output ports, and the third port123and the fourth port124are input ports. The first port121is electrically connected to the antenna radiator110at the first feeding point111, and the second port122is electrically connected to the antenna radiator110at the second feeding point112. The feeding element130is electrically connected to the third port123and the fourth port124. The feeding element130performs feeding to the antenna structure via anti-symmetrical feed. For example, signal amplitudes of electrical signals of the feeding element130at the third port123and the fourth port124are the same, and phases are opposite (for example, opposite phase may be a phase difference of 180°±10°).

It should be understood that the electrical length may be represented by multiplying a physical length (that is, a mechanical length or a geometric length) by a ratio of a transmission time of an electrical or electromagnetic signal in a medium to a time required when the signal passes through a distance the same as the physical length of the medium in free space. The electrical length may meet the following formula:

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

Alternatively, the electrical length may be a ratio of a physical length (that is, a mechanical length or a geometric length) to a wavelength of a transmitted electromagnetic wave, and the electrical length may meet the following formula:

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

In an embodiment, the axis of the antenna radiator may be a virtual symmetry axis of the antenna radiator110, and the antenna radiator is symmetrical to left and right along the axis.

In an embodiment, the first port121of the first circuit120is electrically connected to the antenna radiator110at the first feeding point111via a metal spring, and the second port122is electrically connected to the antenna radiator110at the second feeding point112via a metal spring.

In an embodiment, the antenna structure may be a slot antenna. The antenna radiator110may include a first radiator113and a second radiator114. A first end of the first radiator113and a first end of the second radiator114are opposite and do not contact each other. A slot115is formed between the first end of the first radiator113and the first end of the second radiator114, and a second end of the first radiator113and a second end of the second radiator114may be electrically connected to a ground (ground, GND). For example, the second end of the first radiator113is connected to the ground in a main extension direction of the first radiator113, and/or the second end of the second radiator114is connected to the ground in a main extension direction of the second radiator114. For another example, the second end of the first radiator113is connected to the ground in a direction (different from a main extension direction) in which the first radiator113is bent, and/or the second end of the second radiator114is connected to the ground in a direction (different from a main extension direction) in which the second radiator114is bent. It should be understood that the ground may be a metal layer, a housing, or another metal layer in a PCB of the electronic device.

In an embodiment, the first circuit120may include a first capacitor102and a second capacitor104. The first capacitor102is connected in series between the first port121and the third port123, or the first capacitor102is connected in series between a radio frequency channel formed between the first port121and the third port123, and is configured to match an (L-1/2) wavelength mode of the antenna structure, where L is a positive integer. A first end of the second capacitor104is disposed between the first capacitor102and the first port121, and a second end is disposed between the second port122and the fourth port123. Alternatively, the second capacitor104is connected in parallel between the radio frequency channel formed between the first port121and the third port123and a radio frequency channel formed between the second port122and the fourth port124, and is configured to match an M-time wavelength mode of the antenna structure, where M is a positive integer.

In an embodiment, a capacitance value of the first capacitor102may be less than 2 pF, and a capacitance value of the second capacitor may be less than 4 pF, which may be adjusted according to an actual design or production requirement.

It should be understood that, via the second capacitor104connected in parallel and the first capacitor102connected in series in the first circuit120, a current corresponding to the (L-1/2) wavelength mode and a current in the M-time wavelength mode respectively go through different paths (for example, paths through the first capacitor102, and the second capacitor104, respectively) to implement the matching of the two modes. For example, a boundary condition corresponding to the (L-1/2) wavelength mode is the same as a boundary condition corresponding to the M-time wavelength mode, and may be respectively matched with the (L-1/2) wavelength mode and the M-time wavelength mode. A same boundary condition may be considered as a same impedance corresponding to the antenna modes. Therefore, matching of the two modes can be implemented. The antenna structure shown inFIG.11may generate at least one first resonance via the first capacitor102connected in series in the first circuit120. The antenna structure shown inFIG.11may generate at least one second resonance frequency via the second capacitor104connected in parallel in the first circuit120, to expand an operating bandwidth of the antenna structure. The first resonance may correspond to the (L-1/2) wavelength mode of the antenna structure, and the first capacitor102may be configured to match the (L-1/2) wavelength mode of the antenna structure. The second resonance may correspond to the M-time wavelength mode of the antenna structure, and the second capacitor104may be configured to match the M-time wavelength mode of the antenna structure.

In an embodiment, the first circuit120may include a first inductor101, a second inductor103, and a third inductor105. The first inductor101is connected in series between the first end of the second capacitor104and the first port121, and the second inductor103is connected in series between the second end of the second capacitor104and the second port122. The first inductor101and the second inductor103may be configured to adjust a resonance frequency of the M-time wavelength mode. One end, of the third inductor105is disposed between the first end of the second capacitor104and the first capacitor102, and the other end is disposed between the second end of the second capacitor104and the fourth port124. The third inductor105may be configured to adjust a resonance frequency of the (L-1/2) wavelength mode.

In an embodiment, the antenna structure may further include an anti-symmetrical network140. The anti-symmetrical network140is located between the first circuit120and the feeding element130, and is configured to connect the third port123and the fourth port124of the first circuit120to the feeding element130. In this way, the electrical signal of the feeding element130has a same amplitude but opposite phases at the third port123and the fourth port124.

It should be understood that the anti-symmetrical network140is merely a technical means for implementing opposite phases of the electrical signals of the feeding element130between the third port123and the fourth port124, and opposite phases may also be implemented via other technical means in actual production or design. For example, a balun, and/or a1800coupler, and/or a combination of a 90° coupler and a phase shift network, and the like. This is not limited in this application.

FIG.12toFIG.14are schematic diagrams of simulation structures of the antenna structure shown inFIG.11.FIG.12, is an S-parameter simulation result diagram of the antenna structure shown inFIG.11.FIG.13is a diagram of simulation results of radiation efficiency (radiation efficiency) and total efficiency (total efficiency) of the antenna structure shown inFIG.11.FIG.14is a schematic diagram of current distribution at resonance points of the antenna structure shown inFIG.11.

As shown inFIG.12, when a feeding element operates, the antenna structure generates three resonances, and resonance points of the antenna structure are respectively 1.73 GHz, 3.48 GHz, and 4.43 GHz, where 1.73 GHz corresponds to a half-wavelength mode of the antenna structure. 3.48 GHz corresponds to a one-time wavelength mode of the antenna structure, and 4.43 GHz corresponds to a three-half wavelength mode of the antenna structure.

In an embodiment, operating frequency bands of the antenna structure may respectively cover a high frequency band in long term evolution (long term evolution, LTE), for example, 1700 MHz to 2700 MHz, an N77 (3.3 GHz to 4.2 GHz) frequency band and N79 (4.4 GHz to 5.0 GHz) frequency band in a 5G frequency band. It should be understood that parameters in the antenna structure may also be adjusted, so that the operating frequency bands cover other frequency bands. This application is merely an example, and the operating frequency bands of the antenna structure are not limited.

As shown inFIG.13, in an operating frequency band corresponding to resonance generated by the antenna structure, radiation efficiency is greater than −4 dB, and total efficiency is greater than −8 dB, which may also meet a requirement.

As shown in (a) inFIG.14, when the antenna structure operates at 1.73 GHz, currents of the antenna structure face a same direction, and there is a current zero point. It should be understood that the antenna structure shown inFIG.11is equivalent to a folded electric dipole antenna. For the electric dipole antenna, the current zero point exists at two ends of the radiator. After the radiator is folded to be the antenna structure shown inFIG.11, the current zero point is located at a slot. When the current on the radiator of the electric dipole antenna is in the same direction, the current zero point corresponds to the half-wavelength mode. Therefore, the current distribution shown in (a) inFIG.14corresponds to the half-wavelength mode. As shown in (b) inFIG.14, when the antenna structure operates at 3.48 GHz, there are two current zero points, which are twice that of the antenna structure shown in (a) inFIG.14. Therefore, the two current zero points correspond to the one-time wavelength mode. As shown in (c) inFIG.14, when the antenna structure operates at 4.43 GHz, there are three current zero points. Therefore, the three current zero points correspond to the three-half wavelength mode. Herein, (a), (b), and (c) inFIG.14respectively show that the slot antenna operates in the 1/2 wavelength mode, the one-time wavelength mode, and the 2/3 wavelength mode. It should be understood that: A 1/2 wavelength mode, a one-time wavelength mode, and 2/3 wavelength mode of a wire antenna are also similar, for example, having 1, 2 and 3 current zero points, respectively. Similarly, it can be learned that the antenna structure has (N-1/2)/(1/2) current zero points in the (N-1/2) wavelength mode, and has N/(1/2) current zero points in the N wavelength mode. It should be understood that the current on the radiator is an alternating current, and the current zero point is a current reverse point on the radiator. The operating mode of the antenna structure may be determined via the current zero point on the radiator, to determine that the antenna structure is in an (L-1/2) wavelength mode or an M-time wavelength mode. In addition, due to different antenna structures, a corresponding current zero point may not be on the antenna radiator, but is at a slot formed by the radiator or at a feeding position. This is not limited in this application, and may be determined based on an actual antenna structure.

Therefore, because the antenna structure includes the first circuit, boundary conditions corresponding to the (L-1/2) wavelength mode and the M-time wavelength mode are changed via the first circuit, so that the boundary conditions of the (L-1/2) wavelength mode and the M-time wavelength mode are the same, and simultaneous excitation can be performed. In this case, good matching can be implemented between the (L-1/2) wavelength mode and the M-time wavelength mode of the antenna structure, and a plurality of resonances can be generated in the antenna structure, so that an operating frequency band of the antenna structure can be expanded.

It should be understood that, for the antenna structure shown inFIG.11, a basic form of the antenna structure is a CM slot antenna. By adding the first circuit, the half-wavelength mode, the one-time wavelength mode, and the three-half wavelength mode of the slot antenna in a CM mode are excited. For other antenna forms, such as a wire antenna (for example, a CM mode, a DM mode of the wire antenna), an open slot antenna (for example, a CM mode and a DM mode of the open slot antenna), the (L-1/2) wavelength mode and the M-time wavelength mode of the antenna may also be excited by adding the first circuit.

FIG.15is a schematic diagram of a slot antenna whose two ends are open according to an embodiment of this application.

FIG.15is a schematic diagram of a structure of a slot antenna whose two ends are open. A first circuit of the slot antenna is different from the slot antenna shown inFIG.11. It is because that an initial impedance of the antenna structure starts from a circuit break point, and an initial circle impedance of the slot antenna shown inFIG.11starts from a short-circuit point. Therefore, the first circuit corresponds to the initial circle impedance of the antenna structure. For example, when the initial circle impedance starts from the short-circuit point, the first circuit may select a parallel capacitor and a series capacitor solution, and when the initial circle impedance starts from the circuit break point, the first circuit may select a parallel inductor and a series inductor solution.

It should be understood that, the slot antenna whose two ends are open may be considered that two ends of a radiator of the slot antenna are open, and is not directly connected to another conductor (for example, a ground or another metal mechanical part). For example, in an electronic device, a section of a metal frame is used as the radiator of the slot antenna, and two ends of the radiator are open. It may be considered that two ends of the radiator respectively form a slot with the metal frame, and are not directly connected to the metal frame. The slot formed by the two ends of the radiator with the metal frame may be filled with a dielectric, to meet a strength requirement of the electronic device. At the same time, the two ends of the radiator are open to form a slot antenna whose two ends are open.

As shown inFIG.15, the antenna radiator may include a first radiator151and a second radiator152. A slot181may be formed between an end that is of the first radiator151away from the second radiator152and a ground, and a slot182may be formed between an end that is of the second radiator152away from the first radiator151and the ground. A first circuit160and a feeding element170may be disposed between the first radiator151and the second radiator152, and two feeding points that are electrically connected between the feeding element and the first radiator151and the second radiator152may be symmetrical along a virtual axis of the antenna radiator. An inductor161connected in parallel in the first circuit160may be configured to match an (L-1/2) wavelength mode, and an inductor162connected in series may be configured to match an M-time wavelength mode.

In an embodiment, the slot181may be formed between the end of the first radiator151that is away from the second radiator152and a section of a first electric-conductor, and the slot182may be formed between the end of the second radiator152that is away from the first radiator151and a section of a second electric-conductor.

For brevity of description, in this application, an example in which the first electric-conductor and the second electric-conductor are only a part of the ground is used. This is not limited in this application. In another embodiment of this application, the first electric-conductor and the second electric-conductor may be respectively electrically connected to the ground at first ends of the first electric-conductor and the second electric-conductor. For example, the first electric-conductor and the second electric-conductor are used as radiators of other antenna structures. It should be understood that, an electrical connection of the first end to the ground includes an electrical connection to the ground at the end, and also includes an electrical connection to the ground at a ground point on an electric-conductor near the end.

In an embodiment, a positive electrode of the feeding element170is connected to the first radiator151, and a negative electrode of the feeding element is connected to the second radiator152. In this case, the antenna structure operates in a CM mode.

In an embodiment, an inductance value of the inductor161may be less than 15 nH, and an inductance value of the inductor162may be less than 10 nH, which may be adjusted according to an actual design or production requirement.

It should be understood that the first circuit is configured to make a current path of the (L-1/2) wavelength mode different from a current path of the M-time wavelength mode, to separately match the (L-1/2) wavelength mode and the M-time wavelength mode. In addition, an electronic component may also be added on the first circuit160shown inFIG.15, and an equivalent electrical length of the radiator may be changed, to implement fine-tuning of a resonance frequency, as shown inFIG.16. This is not limited in this application, and may be adjusted according to actual production or design.

In the foregoing embodiment, the first circuit is added to the antenna structure, and at least one (L-1/2) wavelength mode and at least one M-time wavelength mode are excited, for example, a half-wavelength mode, a one-time wavelength mode, and a three-half wavelength mode are excited. If a DM mode feed is added on this basis, the half-wavelength mode, one-time wavelength mode, and three-half wavelength mode of the CM mode, and the half-wavelength mode, one-time wavelength mode, and three-half wavelength mode of the DM mode may be generated together. It should be understood that, because electric fields corresponding to the CM mode and the DM mode are integrally orthogonal in a far field, integral orthogonality may be understood as that an electric field that generates resonance in the CM mode and the DM mode meets the following formula in the far field:

E1(θ,φ) is an electric field of a far field corresponding to a resonance generated in the CM mode, and E2(θ,φ) is an electric field of a far field corresponding to a resonance generated in the DM mode. In a three-dimensional coordinate system, θ is an angle with a z axis, and D is an angle with an x axis on an xoy plane. The electric fields corresponding to the resonance generated in the CM mode and the DM mode are integrally orthogonal between the far fields, and do not affect each other. Therefore, when the antenna structure operates in the CM mode and the DM mode, at least one (L-1/2) wavelength mode and at least one M-time wavelength mode in the CM mode can be generated, and at least one (L-1/2) wavelength mode and at least one M-time wavelength mode in the DM mode can be generated while maintaining high isolation. For example, a first resonance frequency of the CM mode and a first resonance frequency of the DM mode may be in the same frequency and have high isolation. The same frequency may be understood as being in a same frequency band.

FIG.17is a schematic diagram of an antenna structure according to an embodiment of this application.

As shown inFIG.17, the antenna structure may include an antenna radiator210, a first circuit220, a first feeding element231, and a second feeding element232.

Electrical lengths of the antenna radiator210on the left and right of a virtual axis are the same. It should be understood that, in engineering application, antenna structures may not be completely the same due to internal layout of an electronic device. It may be considered that an error range of the electrical lengths of the antenna radiator on the left and right of the axis is within a one-sixteenth operating wavelength, and “same electrical lengths” in this application is met. The antenna radiator210includes a first feeding point231and a second feeding point232. The first feeding point231and the second feeding point232are respectively disposed on two sides of the axis of the antenna radiator210, and the first feeding point231and the second feeding point232are symmetrical along the axis. The first circuit220includes a first port221, a second port222, a third port223, and a fourth port224. The first port221and the second port222are output ports, and the third port223and the fourth port224are input ports. The first port221is electrically connected to the antenna radiator210at the first feeding point211, and the second port222is electrically connected to the antenna radiator210at the second feeding point212. The first feeding element231is electrically connected to the third port223and the fourth port224, and feeds to the antenna structure via symmetrical feed. For the symmetrical feed, for example, signal amplitudes and phases of electrical signals of the first feeding element231between the third port223and the fourth port224are the same. The second feeding element232is electrically connected to the third port223and the fourth port224, and feeds to the antenna structure via anti-symmetrical feed. For the anti-symmetrical feed, for example, signal amplitudes of electrical signals of the second feeding element232between the third port223and the fourth port224are the same, and phases are opposite (for example, a phase difference of 180°).

In an embodiment, the virtual axis of the antenna radiator may be a virtual symmetry axis of the antenna radiator210, and the antenna radiator is symmetrical to left and right along the symmetry axis.

It should be understood that the antenna structure includes a first feeding element that uses symmetrical feed and a second feeding element that uses anti-symmetrical feed. Therefore, the CM mode and the DM mode of the antenna structure may be excited together. The antenna structure may operate in the at least one (L-1/2) wavelength mode and at least one M-time wavelength mode, where L and M are positive integers. The antenna structure may generate a resonant frequency band with a same frequency and high isolation, to meet a requirement of communication for a bandwidth and isolation.

At the same time, for a first antenna unit formed between the first feeding element231and the antenna radiator210and a second antenna unit formed between the second feeding element232and the antenna radiator210, the two antenna units multiplex a same antenna radiator (for example, a first radiator213and a second radiator214shown in the figure), space occupied by the antenna unit can be greatly reduced.

In an embodiment, the first port221of the first circuit220is electrically connected to the antenna radiator210at the first feeding point211via a metal spring, and the second port222is electrically connected to the antenna radiator210at the second feeding point212via a metal spring.

In an embodiment, the antenna structure may be a slot antenna whose two ends are open. It may be understood that two ends of the radiator of the slot antenna are open and are not directly connected to a ground, another electric-conductor, or the like. The antenna radiator210may include the first radiator213and the second radiator214. The first radiator213and the second radiator214may be respectively disposed on two sides of a virtual axis, and electrical lengths of the first radiator213and the second radiator214are equal. A first end of the first radiator213and a first end of the second radiator214are opposite and do not contact each other, and a slot215is formed between the first end of the first radiator213and the first end of the second radiator214. A slot216is formed between a second end of the first radiator213and the ground, and a slot217is formed between a second end of the second radiator214and the ground. It should be understood that the ground may be a metal layer, a housing, or another metal layer in a PCB of the electronic device.

In an embodiment, the slot216may be formed between the second end of the first radiator213and a first electric-conductor, and the slot217may be formed between the second end of the second radiator214and a second electric-conductor. Alternatively, a first dielectric is disposed at the second end of the first radiator213, to implement “open” of the second end of the first radiator213. Similarly, a second dielectric may be disposed at the second end of the second radiator214to implement “open” of the second end of the second radiator214.

In an embodiment, the first circuit220may further include a first inductor201, a second inductor202, a third inductor203, and a fourth inductor204. The first inductor201is connected in series between the first port221and the third port223, the third inductor203is connected in series between the second port222and the fourth port224, and the first inductor201and the third inductor203may be configured to match an N-time wavelength mode of the antenna structure. The second inductor202is connected in parallel between the first inductor201and the first port221and is grounded, the fourth inductor204is connected in parallel between the third inductor203and the second port222and is grounded, and the second inductor202and the fourth inductor204may be configured to match the (N-1/2) wavelength mode of the antenna structure.

It should be understood that an inductor is connected in series and parallel between an input port and an output port of the first circuit in the antenna structure shown inFIG.17. For example, an inductor is connected in parallel and in series in a radio frequency channel formed between the first port221and the third port223in sequence. A current corresponding to the (L-1/2) wavelength mode and a current corresponding to the M-time wavelength mode go separately through different paths, to separately implement matching between the two modes. For example, a boundary condition corresponding to the (L-1/2) wavelength mode is the same as a boundary condition corresponding to the M-time wavelength mode, and may be respectively matched with the (L-1/2) wavelength mode and the M-time wavelength mode. A same boundary condition may be considered as a same impedance corresponding to the antenna modes. Therefore, matching of the two modes can be implemented. The antenna structure shown inFIG.17may generate at least one first resonance via the second inductor202and the fourth inductor204in the first circuit220. The antenna structure shown inFIG.17may generate at least one second resonance via the first inductor201and the third inductor203in the first circuit220, to expand an operating bandwidth of the antenna structure. The first resonance may correspond to the (L-1/2) wavelength mode of the antenna structure, and the second inductor202and the fourth inductor204may be configured to match the (L-1/2) wavelength mode of the antenna structure. The second resonance may correspond to the M-time wavelength mode of the antenna structure, and the first inductor201and the third inductor203may be configured to match the M-time wavelength mode of the antenna structure.

In an embodiment, an electronic component disposed between the first port221and the third port223and an electronic component disposed between the second port222and the fourth port224are symmetrical to each other. For example, the first inductor201and the third inductor203are symmetrical to each other, and inductance values are the same. The second inductor202and the fourth inductor204are symmetrical to each other, and inductance values are the same.

In an embodiment, the first circuit220may include a first capacitor205, a second capacitor206, a third capacitor207, and a fourth capacitor208. The first capacitor205is connected in series between the second inductor202and the first port221, and the third capacitor207is connected in series between the second port222and the fourth inductor204. The first capacitor205and the third capacitor207may be configured to adjust a resonance frequency of the M-time wavelength mode. The second capacitor206is connected in parallel between the first inductor201and the second inductor202and is grounded, and the fourth capacitor208is connected in parallel between the third inductor203and the fourth inductor204and is grounded. The second capacitor206and the fourth capacitor208may be configured to adjust a resonance frequency of the (L-1/2) wavelength mode.

In an embodiment, the antenna structure may further include a 180° directional coupler240that is located between the first circuit220and the feeding element, for example, between the first feeding element231, the second feeding element121, and the third port123and the fourth port124of the first circuit120, so that phases of electrical signals of the first feeding element231between the third port223and the fourth port224are the same, and phases of electrical signals of the second feeding element232between the third port223and the fourth port224are opposite.

It should be understood that the 180° directional coupler240is merely a technical means for implementing same or opposite phases of the electrical signals of the feeding element between the third port123and the fourth port124, and opposite phases may also be implemented via other technical means in actual production or design. For example, a balun, and/or a 180° coupler, and/or a combination of a 90° coupler and a phase shift network, and the like. This is not limited in this application.

In an embodiment, the antenna structure may further include a first matching network251and a second matching network252. The first matching network251is configured to adjust an impedance of the first feeding element231, to minimize a transmission loss and distortion of an electrical signal. The second matching network252is configured to adjust an impedance of the second feeding element232, to minimize a transmission loss and distortion of an electrical signal.

In an embodiment, the first matching network251and the second matching network252may be an LC network or another type of network, and may be selected according to actual production or design. This is not limited in this application.

FIG.18andFIG.19are schematic diagrams of simulation results of the antenna structure shown inFIG.17.FIG.18is an S-parameter simulation result diagram of the antenna structure shown inFIG.17.FIG.19is a diagram of simulation results of radiation efficiency and total efficiency of the antenna structure shown inFIG.17.

As shown inFIG.18, when a first feeding element feeds, an electrical signal of the first feeding element is fed into an antenna radiator through a first port and a second port. An S parameter corresponding to the antenna structure is S11. A half-wavelength mode and a one-time wavelength mode may be excited, and the antenna structure may operate in a plurality of resonant frequency bands. When a second feeding element feeds, an electrical signal of the second feeding element is fed into the antenna radiator through the first port and the second port. The S parameter corresponding to the antenna structure is S22. The half-wavelength mode and the one-time wavelength mode may also be excited, and the antenna structure may operate in a plurality of resonant frequency bands. When the operating bandwidth of the antenna structure is ensured, because the first feeding element and the second feeding element respectively excite the DM mode and the CM mode of the antenna structure, in a same frequency band, good isolation can be maintained between resonant frequency bands respectively excited by the first feeding element and the second feeding element, and a worst isolation between the two is −30 dB.

It should be understood that, for the antenna structure shown inFIG.17, better symmetry of the structure indicates better isolation between resonant frequency bands respectively excited by the first feeding element and the second feeding element.

As shown inFIG.19, in an operating frequency band corresponding to resonance generated by the antenna structure, radiation efficiency is greater than −3 dB, and total efficiency is greater than −6 dB, which may meet a communication requirement.

FIG.20is a schematic diagram of an antenna structure according to an embodiment of this application. Different from the antenna structure shown inFIG.17, a radiator of the antenna structure shown inFIG.20is a complete metal mechanical part, and no slot is provided on the radiator. Other structures are the same. For brevity of description, details are not described one by one.

It should be understood that a first circuit provided in this embodiment of this application may be adjusted based on different antenna structures, so that the different antenna structures excite at least one (L-1/2) wavelength mode and at least one M-time wavelength mode.

As shown inFIG.20, the antenna structure may be a slot antenna whose two ends are open. Structurally, two ends of a radiator of the slot antenna whose two ends are open are not connected to a ground. An antenna radiator310may be a complete conductor, for example, a complete metal piece. One end of the antenna radiator310and the ground may form a slot311, and the other end of the antenna radiator310and the ground may form a slot312. The antenna structure may operate in at least one (L-1/2) wavelength mode and at least one M-time wavelength mode, where L and M are positive integers.

In an embodiment, the slot311may be formed between a first end of the antenna radiator310and a first electric-conductor, and the slot312may be formed between a second end of the antenna radiator310and a second electric-conductor. Alternatively, a first dielectric is disposed at the first end of the antenna radiator310, so that the first end of the antenna radiator310is “open”. Similarly, a second dielectric may be disposed at the second end of the antenna radiator310, so that the second end of the antenna radiator310is “open”.

In an embodiment, the first circuit320may include a first capacitor301, a second capacitor302, and a third capacitor303. The first capacitor301is connected in series between a first port321and a third port323, and the second capacitor302is connected in series between a second port322and a fourth port324. The first capacitor301and the second capacitor302may be configured to match an (N-1/2) wavelength mode of the antenna structure. A first end of the third capacitor303is disposed between the first capacitor301and the first port321, and a second end is disposed between the second capacitor302and the second port322. To be specific, the third capacitor303is connected in parallel between a radio frequency channel formed between the first port321and the third port323and a radio frequency channel formed between the second port322and the fourth port324, and is configured to match an N-time wavelength mode of the antenna structure.

It should be understood that the capacitors are connected in parallel and connected in series in the first circuit320, and the current corresponding to the (L-1/2) wavelength mode and the current of the M-time wavelength mode go through different paths, to separately implement matching between the two modes. For example, a boundary condition corresponding to the (L-1/2) wavelength mode is the same as a boundary condition corresponding to the M-time wavelength mode, and may be respectively matched with the (L-1/2) wavelength mode and the M-time wavelength mode. A same boundary condition may be considered as a same impedance corresponding to the antenna modes. Therefore, matching of the two modes can be implemented. The antenna structure may generate at least one first resonance via the first capacitor301and the second capacitor302in the first circuit320. The antenna structure may generate at least one second resonance via the third capacitor303in the first circuit320. The first resonance may correspond to the (L-1/2) wavelength mode of the antenna structure, and the first capacitor301and the second capacitor302may be configured to match the (L-1/2) wavelength mode of the antenna structure. The second resonance may correspond to an M-time wavelength mode of the antenna structure, and the third capacitor303may be configured to match the M-time wavelength mode of the antenna structure.

In an embodiment, an electronic component disposed between the first port321and the third port323and an electronic component disposed between the second port322and the fourth port324are symmetrical to each other. For example, the first capacitor301and the second capacitor302are symmetrical to each other, and capacitance values are the same.

In an embodiment, the first circuit320may further include a first inductor304and a second inductor305. The first inductor304is connected in parallel between the first capacitor301and a first end of the third capacitor303and is grounded, and the second inductor305is disposed between the second capacitor302and a second end of the third capacitor303in parallel to the ground. The first inductor304and the second inductor305may be configured to adjust a resonance frequency of the (L-1/2) wavelength mode.

FIG.21toFIG.23are schematic diagrams of simulation structures of the antenna structure shown inFIG.20.FIG.21is an S-parameter simulation result diagram of the antenna structure shown inFIG.20.FIG.22is a diagram of an isolation simulation result of the antenna structure shown inFIG.20.FIG.23is a diagram of simulation results of radiation efficiency and total efficiency of the antenna structure shown inFIG.20.

As shown inFIG.21, when a first feeding element feeds, an S parameter corresponding to the antenna structure is S11. A half-wavelength mode and a one-time wavelength mode may be excited, and the antenna structure may operate in a plurality of resonant frequency bands. When a second feeding element feeds, the S parameter corresponding to the antenna structure is S22. The half-wavelength mode and the one-time wavelength mode may also be excited, and the antenna structure may operate in a plurality of resonant frequency bands. It should be understood that, when the second feeding element operates, because a matching network is connected, one of resonant frequency bands corresponding to the half-wavelength mode is generated by the matching network.

In an embodiment, operating frequency bands of the antenna structure may respectively cover a high frequency band in LTE, for example, 1700 MHz to 2700 MHz, an N77 (3.3 GHz to 4.2 GHz) frequency band and N79 (4.4 GHz to 5.0 GHz) frequency band in a 5G frequency band. It should be understood that parameters in the antenna structure may also be adjusted, so that the operating frequency bands cover other frequency bands. This application is merely an example, and the operating frequency bands of the antenna structure are not limited.

As shown inFIG.22, when the operating bandwidth of the antenna structure is ensured, because the first feeding element and the second feeding element respectively excite the DM mode and the CM mode of the antenna structure, in a same frequency band, good isolation can be maintained between resonant frequency bands respectively excited by the first feeding element and the second feeding element, and a worst isolation between the two is −47 dB.

As shown inFIG.23, in an operating frequency band corresponding to resonance generated by the antenna structure, radiation efficiency is greater than −3 dB, and total efficiency is greater than −8 dB, which may meet a communication requirement.

FIG.24is a schematic diagram of an antenna structure according to an embodiment of this application.

It should be understood that a first circuit provided in this embodiment of this application may be adjusted based on different antenna structures, so that the different antenna structures may excite at least one (L-1/2) wavelength mode and at least one M-time wavelength mode, where L and M are positive integers.

As shown inFIG.24, the antenna structure may be a wire antenna, and an antenna radiator410may be a complete conductor, for example, a complete metal piece.

In an embodiment, a first circuit420may include a first capacitor401, a second capacitor402, and a third capacitor403. The first capacitor401is connected in series between a first port421and a third port423, and the second capacitor402is connected in series between a second port422and a fourth port424. The first capacitor401and the second capacitor402may be configured to match an (N-1/2) wavelength mode of the antenna structure. A first end of the third capacitor403is disposed between the first capacitor401and the first port421, and a second end is disposed between the second capacitor402and the second port422. To be specific, the third capacitor403is connected in parallel between a radio frequency channel formed between the first port421and the third port423and a radio frequency channel formed between the second port422and the fourth port424, and is configured to match an N-time wavelength mode of the antenna structure.

In an embodiment, an electronic component disposed between the first port421and the third port423and an electronic component disposed between the second port422and the fourth port424are symmetrical to each other. For example, the first capacitor401and the second capacitor402are symmetrical to each other, and capacitance values are the same.

It should be understood that the capacitors are connected in parallel and connected in series in the first circuit420, and the current corresponding to the (L-1/2) wavelength mode and the current of the M-time wavelength mode go through different paths, to separately implement matching between the two modes. For example, a boundary condition corresponding to the (L-1/2) wavelength mode is the same as a boundary condition corresponding to the M-time wavelength mode, and may be respectively matched with the (L-1/2) wavelength mode and the M-time wavelength mode. A same boundary condition may be considered as a same impedance corresponding to the two modes. Therefore, matching of the two modes can be implemented. The antenna structure shown inFIG.11may generate at least one first resonance via the first capacitor401and the second capacitor402in the first circuit420. The antenna structure shown inFIG.11may generate at least one second resonance via the third capacitor403in the first circuit420. The first resonance may correspond to the (L-1/2) wavelength mode of the antenna structure, and the first capacitor401and the second capacitor402may be configured to match the (L-1/2) wavelength mode of the antenna structure. The second resonance may correspond to an M-time wavelength mode of the antenna structure, and the third capacitor403may be configured to match the M-time wavelength mode of the antenna structure.

In an embodiment, the first circuit420may further include a first inductor404and a second inductor405. The first inductor404is connected in parallel between the first capacitor401and a first end of the third capacitor403and is grounded, and the second inductor405is disposed between the second capacitor402and a second end of the third capacitor403in parallel to the ground. The first inductor404and the second inductor405may be configured to adjust a resonance frequency of the (L-1/2) wavelength mode.

FIG.25toFIG.27are schematic diagrams of simulation structures of the antenna structure shown inFIG.24.FIG.25is an S-parameter simulation result diagram of the antenna structure shown inFIG.24.FIG.26is a diagram of an isolation simulation result of the antenna structure shown inFIG.24.FIG.17is a diagram of simulation results of radiation efficiency and total efficiency of the antenna structure shown inFIG.24.

As shown inFIG.25, when a first feeding element feeds, an S parameter corresponding to the antenna structure is S11. A half-wavelength mode and a one-time wavelength mode may be excited, and the antenna structure may operate in a plurality of resonant frequency bands. When a second feeding element feeds, the S parameter corresponding to the antenna structure is S22. The half-wavelength mode and the one-time wavelength mode may also be excited, and the antenna structure may operate in a plurality of resonant frequency bands. It should be understood that, when the second feeding element operates, because a matching network is connected, one of resonant frequency bands corresponding to the half-wavelength mode is generated by the matching network.

In an embodiment, operating frequency bands of the antenna structure may respectively cover a high frequency band in LTE, for example, 1700 MHz to 2700 MHz, an N77 (3.3 GHz to 4.2 GHz) frequency band and N79 (4.4 GHz to 5.0 GHz) frequency band in a 5G frequency band. It should be understood that parameters in the antenna structure may also be adjusted, so that the operating frequency bands cover other frequency bands. This application is merely an example, and the operating frequency bands of the antenna structure are not limited.

As shown inFIG.26, when the operating bandwidth of the antenna structure is ensured, because the first feeding element and the second feeding element respectively excite the DM mode and the CM mode of the antenna structure, in a same frequency band, good isolation can be maintained between resonant frequency bands respectively excited by the first feeding element and the second feeding element, and a worst isolation between the two is −45.5 dB.

As shown inFIG.27, in an operating frequency band corresponding to resonance generated by the antenna structure, radiation efficiency is greater than −2 dB, and total efficiency is greater than −8 dB, which may meet a communication requirement.

FIG.28is a schematic diagram of an antenna structure according to an embodiment of this application.

It should be understood that a first circuit provided in this embodiment of this application may be adjusted based on different antenna structures, so that the different antenna structures excite at least one (L-1/2) wavelength mode and at least one M-time wavelength mode, where L and M are positive integers.

As shown inFIG.28, the antenna structure510may be a slot antenna whose two ends are short-circuit. The antenna radiator510may include a first radiator511and a second radiator512. A first end of the first radiator511is opposite to a first end of the second radiator512and does not contact each other. A slot513is formed between the first end of the first radiator511and the first end of the second radiator512, and a second end of the first radiator511and a second end of the second radiator512may be electrically connected to a ground (ground, GND) to form short-circuit. For example, the second end of the first radiator511is connected to the ground in a main extension direction of the first radiator511, and/or the second end of the second radiator512is connected to the ground in a main extension direction of the second radiator512. For another example, the second end of the first radiator511is connected to the ground in a direction (different from a main extension direction) in which the first radiator511is bent, and/or the second end of the second radiator512is connected to the ground in a direction (different from a main extension direction) in which the second radiator512is bent.

It should be understood that, for the slot antenna whose two ends are short-circuit, it may be considered that two ends of the radiator of the slot antenna are directly connected to the ground. For example, in an electronic device, the radiator of the slot antenna is a section of a metal frame, and short-circuit at two ends of the radiator may be considered as that the two ends of the radiator are directly connected to the metal frame respectively.

In an embodiment, a first circuit520may include a first capacitor501, a second capacitor502, and a third capacitor503. The first capacitor501is connected in series between a first port521and a third port523, and the second capacitor502is connected in series between a second port522and a fourth port524. The first capacitor501and the second capacitor502may be configured to match an (N-1/2) wavelength mode of the antenna structure. A first end of the third capacitor503is disposed between the first capacitor501and the first port521, and a second end is disposed between the second capacitor502and the second port522. To be specific, the third capacitor503is connected in parallel between a radio frequency channel formed between the first port521and the third port523and a radio frequency channel formed between the second port522and the fourth port524, and is configured to match an N-time wavelength mode of the antenna structure.

It should be understood that the capacitors are connected in parallel and connected in series in the first circuit520, and the current corresponding to the (L-1/2) wavelength mode and the current of the M-time wavelength mode go through different paths, to separately implement matching between the two modes. For example, a boundary condition corresponding to the (L-1/2) wavelength mode is the same as a boundary condition corresponding to the M-time wavelength mode, and may be respectively matched with the (L-1/2) wavelength mode and the M-time wavelength mode. A same boundary condition may be considered as a same impedance corresponding to the two modes. Therefore, matching of the two modes can be implemented. The antenna structure shown inFIG.11may generate at least one first resonance via the first capacitor501and the second capacitor502in the first circuit520. The antenna structure shown inFIG.11may generate at least one second resonance via the third capacitor503in the first circuit520. The first resonance may correspond to the (L-1/2) wavelength mode of the antenna structure, and the first capacitor501and the second capacitor502may be configured to match the (L-1/2) wavelength mode of the antenna structure. The second resonance may correspond to an M-time wavelength mode of the antenna structure, and the third capacitor503may be configured to match the M-time wavelength mode of the antenna structure.

In an embodiment, an electronic component disposed between the first port521and the third port523and an electronic component disposed between the second port522and the fourth port524are symmetrical to each other. For example, the first capacitor501and the second capacitor502are symmetrical to each other, and capacitance values are the same.

In an embodiment, the first circuit320may further include a first inductor504, a second inductor505, and a third inductor506. The first inductor504is connected in series between the first port521and a first end of the third capacitor503, the second inductor505is connected in series between the second port522and a second end of the third capacitor503, and the first inductor504and the second inductor505may be configured to adjust a resonance frequency of the M-time wavelength mode. A first end of the third inductor506is disposed between a first end of the third capacitor503and the first capacitor501, and a second end of the third inductor506is disposed between a second end of the third capacitor503and the second capacitor502. To be specific, the third inductor506is connected in parallel between a radio frequency channel formed between the first port521and the third port523and a radio frequency channel formed between the second port522and the fourth port524, and may be configured to adjust a resonance frequency of the (L-1/2) wavelength mode of the antenna structure.

FIG.29andFIG.30are schematic diagrams of simulation structures of the antenna structure shown inFIG.28.FIG.29is an S-parameter simulation result diagram of the antenna structure shown inFIG.28.FIG.30is a diagram of an isolation simulation result of the antenna structure shown inFIG.28.

As shown inFIG.29, when a first feeding element feeds, an S parameter corresponding to the antenna structure is S11. A half-wavelength mode and a one-time wavelength mode may be excited, and the antenna structure may operate in a plurality of resonant frequency bands. When a second feeding element feeds, the S parameter corresponding to the antenna structure is S22. The half-wavelength mode and the one-time wavelength mode may also be excited, and the antenna structure may operate in a plurality of resonant frequency bands.

In an embodiment, operating frequency bands of the antenna structure may respectively cover a high frequency band in LTE, for example, 1700 MHz to 2700 MHz, an N77 (3.3 GHz to 4.2 GHz) frequency band and N79 (4.4 GHz to 5.0 GHz) frequency band in a 5G frequency band. It should be understood that parameters in the antenna structure may also be adjusted, so that the operating frequency bands cover other frequency bands. This application is merely an example, and the operating frequency bands of the antenna structure are not limited.

As shown inFIG.30, when the operating bandwidth of the antenna structure is ensured, because the first feeding element and the second feeding element respectively excite the DM mode and the CM mode of the antenna structure, in a same frequency band, good isolation can be maintained between resonant frequency bands respectively excited by the first feeding element and the second feeding element, and a worst isolation between the two is −42 dB.