Antenna and electronic device

Abstract

The present application provides an antenna and an electronic device. The antenna comprises: a substrate; a radiator, wherein the radiator is provided on the surface of the substrate, and the distance between a feed point of the radiator and a central symmetry axis of the radiator is greater than 0; and a first parasitic stub and a second parasitic stub, wherein the first parasitic stub and the second parasitic stub are respectively arranged on two sides of the radiator in a first polarization direction, the projections of the first parasitic stub and the second parasitic stub in the first polarization direction partially overlap the radiator, the first parasitic stub and the second parasitic stub are arranged symmetrically about the center of the radiator, the lengths of the first parasitic stub and the second parasitic stub in a second polarization direction are equal, and the first polarization direction is orthogonal to the second polarization direction. The antenna provided by the present application still has a large circular polarization bandwidth, high radiation efficiency, and high gain even under an ultra-low profile.

Description

Antennas and electronic equipment

[0001] This application claims priority to Chinese Patent Application No. 202411190505.9, filed on August 27, 2024, entitled "Antenna and Electronic Equipment", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of antenna technology, and more particularly to an antenna and electronic device. Background Technology

[0003] With the development of communication technology, electronic devices are trending towards thinner, lighter, smaller, and more multifunctional designs, requiring antennas to occupy less space while meeting diverse communication needs. Ultra-low profile antennas, whose thickness or height is much smaller than the wavelength of electromagnetic waves corresponding to their operating frequency band, face increasing demands and challenges in antenna design. However, ultra-low profile antennas are prone to zero radiation efficiency within their operating frequency band. Therefore, improving the radiation efficiency of ultra-low profile antennas within their operating frequency band is an urgent problem to be solved. Summary of the Invention

[0004] This application provides an antenna and electronic device. The antenna has circular polarization characteristics and improves the zero point of radiation efficiency in the operating frequency band through a novel coupling design, thereby increasing the circular polarization bandwidth of the antenna and achieving high radiation efficiency and gain in the operating frequency band.

[0005] In a first aspect, an antenna is provided, comprising: a substrate; a radiator disposed on the surface of the substrate, wherein the distance between the feed point of the radiator and the central axis of symmetry of the radiator is greater than 0; a first parasitic branch and a second parasitic branch; the first parasitic branch and the second parasitic branch are respectively disposed on both sides of the radiator in a first polarization direction, the projections of the first parasitic branch and the second parasitic branch in the first polarization direction partially overlap with the radiator, the first parasitic branch and the second parasitic branch are centrally symmetrical with respect to the center of the radiator; the first parasitic branch and the second parasitic branch have equal lengths in a second polarization direction; the first polarization direction and the second polarization direction are orthogonal.

[0006] Based on the above technical solution, the antenna provided in this application adopts an eccentric feeding method, which can excite two mutually orthogonal polarization modes. These two polarization modes together form circular polarization. By setting parasitic branches on both sides of the first polarization direction of the radiator, the circular polarization bandwidth of the antenna can be improved.

[0007] In conjunction with the first aspect, in some implementations of the first aspect, the length of the first parasitic branch in the second polarization direction is between 0.8 and 1.2 times the length of the radiator; the length of the second parasitic branch in the second polarization direction is between 0.8 and 1.2 times the length of the radiator.

[0008] In conjunction with the first aspect, in some implementations of the first aspect, the number of the first parasitic branch and the number of the second parasitic branch are multiple and equal.

[0009] In conjunction with the first aspect, in certain implementations of the first aspect, among the plurality of first parasitic branches, the non-overlapping portion of the projection of the first parasitic branch and the adjacent first parasitic branch near the radiator in the first polarization direction has the same length in the second polarization direction, and is less than or equal to 5.5% of the operating wavelength of the radiator; among the plurality of second parasitic branches, the non-overlapping portion of the projection of the second parasitic branch and the adjacent second parasitic branch near the radiator in the first polarization direction has the same length in the second polarization direction, and is less than or equal to 5.5% of the operating wavelength of the radiator.

[0010] In conjunction with the first aspect, in some implementations of the first aspect, the projections of multiple first parasitic branches in the first polarization direction completely overlap; the projections of multiple second parasitic branches in the first polarization direction completely overlap.

[0011] Based on the above technical solution, there can be multiple parasitic stubs added at both ends of the first polarization direction of the radiator. Through multiple parasitic stubs, the troughs of the antenna's radiation efficiency within the operating frequency band can be transferred outside the operating frequency band.

[0012] In conjunction with the first aspect, in some implementations of the first aspect, the length of the projection of the portion of the first parasitic branch that does not overlap with the radiator in the first polarization direction onto the second polarization direction is less than or equal to 5.5% of the operating wavelength of the radiator; and the length of the projection of the portion of the second parasitic branch that does not overlap with the radiator in the first polarization direction onto the second polarization direction is less than or equal to 5.5% of the operating wavelength of the radiator.

[0013] Based on the above technical solution, by adjusting the central symmetry of the parasitic stubs of the antenna, when the parasitic stubs are staggered, energy can be coupled to the parasitic stubs in the orthogonal direction, thereby improving the radiation efficiency in the operating frequency band.

[0014] In conjunction with the first aspect, in some implementations of the first aspect, the distance between the first parasitic branch adjacent to the radiator and the radiator in the first polarization direction is greater than or equal to 1.75% and less than or equal to 2.8% of the operating wavelength of the radiator; the distance between the second parasitic branch adjacent to the radiator and the radiator in the first polarization direction is greater than or equal to 1.75% and less than or equal to 2.8% of the operating wavelength of the radiator.

[0015] In conjunction with the first aspect, in some implementations of the first aspect, the distances between the plurality of first parasitic branches in the first polarization direction are equal and greater than or equal to 1.2% and less than or equal to 1.9% of the operating wavelength of the radiator; the distances between the plurality of second parasitic branches in the first polarization direction are equal and greater than or equal to 1.2% and less than or equal to 1.9% of the operating wavelength of the radiator.

[0016] Based on the above technical solution, the common-mode resonance position of the antenna within the operating frequency band can be adjusted, and the position of the concave point of radiation efficiency outside the operating frequency band has little impact, thus ensuring high radiation efficiency of the antenna within the operating frequency band.

[0017] In conjunction with the first aspect, in some implementations of the first aspect, the antenna further includes: a third parasitic stub and a fourth parasitic stub; the third parasitic stub and the fourth parasitic stub are respectively disposed on both sides of the radiator in the second polarization direction, the projections of the third parasitic stub and the fourth parasitic stub in the second polarization direction partially overlap with the radiator, the third parasitic stub and the fourth parasitic stub are centrally symmetrical with respect to the center of the radiator; the lengths of the third parasitic stub and the fourth parasitic stub are equal in the first polarization direction.

[0018] Based on the above technical solution, by adding a third and a fourth parasitic stub at both ends of the second polarization direction of the radiator, the circular polarization bandwidth of the antenna can be further widened, and the radiation efficiency of the antenna in the operating frequency band can be improved.

[0019] In conjunction with the first aspect, in some implementations of the first aspect, the length of the third parasitic branch in the first polarization direction is between 0.8 and 1.2 times the length of the radiator; the length of the fourth parasitic branch in the first polarization direction is between 0.8 and 1.2 times the length of the radiator.

[0020] In conjunction with the first aspect, in some implementations of the first aspect, the number of the third parasitic branch and the fourth parasitic branch is multiple and equal.

[0021] In conjunction with the first aspect, in some implementations of the first aspect, among the plurality of third parasitic branches, the non-overlapping portion of the projection of the third parasitic branch and the adjacent third parasitic branch near the radiator in the second polarization direction has the same length in the first polarization direction and is less than or equal to 5.5% of the operating wavelength of the radiator; among the plurality of fourth parasitic branches, the non-overlapping portion of the projection of the fourth parasitic branch and the adjacent fourth parasitic branch near the radiator in the second polarization direction has the same length in the first polarization direction and is less than or equal to 5.5% of the operating wavelength of the radiator.

[0022] In conjunction with the first aspect, in some implementations of the first aspect, the projections of the plurality of third parasitic branches in the second polarization direction completely overlap; the projections of the plurality of fourth parasitic branches in the second polarization direction completely overlap.

[0023] In conjunction with the first aspect, in some implementations of the first aspect, the length of the projection of the portion of the third parasitic branch that does not overlap with the radiator in the second polarization direction in the first polarization direction is less than or equal to 5.5% of the operating wavelength of the radiator; and the length of the portion of the fourth parasitic branch that does not overlap with the radiator in the second polarization direction in the first polarization direction is less than or equal to 5.5% of the operating wavelength of the radiator.

[0024] Based on the above technical solution, by adjusting the central symmetry of the parasitic stubs of the antenna, when the parasitic stubs are staggered, energy can be coupled to the parasitic stubs in the orthogonal direction, thereby improving the radiation efficiency in the operating frequency band.

[0025] In conjunction with the first aspect, in certain implementations of the first aspect, the distance between the third parasitic branch adjacent to the radiator and the radiator in the second polarization direction is greater than or equal to 1.75% and less than or equal to 2.8% of the operating wavelength of the radiator; the distance between the fourth parasitic branch adjacent to the radiator and the radiator in the second polarization direction is greater than or equal to 1.75% and less than or equal to 2.8% of the operating wavelength of the radiator.

[0026] In conjunction with the first aspect, in some implementations of the first aspect, the spacing between the plurality of third parasitic branches in the second polarization direction is equal and greater than or equal to 1.2% and less than or equal to 1.9% of the operating wavelength of the radiator; the spacing between the plurality of fourth parasitic branches in the second polarization direction is equal and greater than or equal to 1.2% and less than or equal to 1.9% of the operating wavelength of the radiator.

[0027] Based on the above technical solution, the common-mode resonance position of the antenna within the operating frequency band can be adjusted, and the position of the concave point of radiation efficiency outside the operating frequency band has little impact, thus ensuring high radiation efficiency of the antenna within the operating frequency band.

[0028] In conjunction with the first aspect, in some implementations of the first aspect, the radiator is a rectangular radiator, the first parasitic branch and the second parasitic branch are both rectangular parasitic branches, and the distance between the feed point of the radiator and the diagonal of the radiator is greater than 0.

[0029] In some possible implementations, the third parasitic segment and the fourth parasitic segment are rectangular parasitic segments.

[0030] In conjunction with the first aspect, in some implementations of the first aspect, the radiator is a circular radiator, and the first parasitic branch and the second parasitic branch are respectively arc-shaped parasitic branches.

[0031] In some possible implementations, the third parasitic segment and the fourth parasitic segment are respectively arc-shaped parasitic segments.

[0032] In conjunction with the first aspect, in some implementations of the first aspect, a plurality of capacitor pillars are provided on the inner side of the radiator.

[0033] Based on the above technical solution, setting multiple capacitor pillars inside the radiator can change the current distribution in the antenna, reducing the size of the antenna by 25%-35%, which is beneficial for antenna miniaturization.

[0034] In conjunction with the first aspect, in some implementations of the first aspect, the thickness of the substrate is greater than or equal to 0.4 mm and less than or equal to 0.5 mm.

[0035] In a second aspect, an electronic device is provided, which includes an antenna as described in the first aspect and any implementation thereof. Attached Figure Description

[0036] Figure 1 is a schematic diagram of an electronic device provided in an embodiment of this application.

[0037] Figure 2 is a schematic diagram of the structure of an antenna 100.

[0038] Figure 3 is a schematic diagram of the performance of the antenna 100 shown in Figure 2.

[0039] Figure 4 is a schematic diagram of an antenna 200 provided in an embodiment of this application.

[0040] Figure 5 is a schematic diagram of the performance of the antenna 200 shown in Figure 4.

[0041] Figure 6 is a schematic diagram of the current distribution of the antenna 200 shown in Figure 4.

[0042] Figure 7 is a schematic diagram of the current distribution of the antenna 200 shown in Figure 4.

[0043] Figure 8 is a schematic diagram of an antenna 300 provided in an embodiment of this application.

[0044] Figure 9 is a performance schematic diagram of the antenna 300 shown in Figure 8.

[0045] Figure 10 is a schematic diagram of the current distribution of the antenna 300 shown in Figure 8.

[0046] Figure 11 is a schematic diagram of the current distribution of the antenna 300 shown in Figure 8.

[0047] Figure 12 is a schematic diagram of another antenna 400 provided in an embodiment of this application.

[0048] Figure 13 is a schematic diagram of the performance of the antenna 400 shown in Figure 12.

[0049] Figure 14 shows the radiation pattern and axial ratio pattern of the antenna 400 shown in Figure 12.

[0050] Figure 15 is a current distribution diagram of the antenna 400 shown in Figure 12.

[0051] Figure 16 is a schematic diagram of another antenna 500 provided in an embodiment of this application.

[0052] Figure 17 is a performance schematic diagram of the antenna 500 shown in Figure 16.

[0053] Figure 18 is a schematic diagram of another antenna 600 provided in an embodiment of this application.

[0054] Figure 19 is a performance schematic diagram of the antenna 600 shown in Figure 18.

[0055] Figure 20 is a schematic diagram of another antenna 700 provided in an embodiment of this application.

[0056] Figure 21 is a performance schematic diagram of the antenna 700 shown in Figure 20.

[0057] Figure 22 is a schematic diagram of another antenna 800 provided in an embodiment of this application.

[0058] Figure 23 is a performance schematic diagram of the antenna 800 shown in Figure 22.

[0059] Figure 24 is a schematic diagram of the current distribution of the antenna 800 shown in Figure 22.

[0060] Figure 25 is a schematic diagram of another antenna 900 provided in an embodiment of this application.

[0061] Figure 26 is a performance schematic diagram of the antenna 900 shown in Figure 25.

[0062] Figure 27 shows the radiation pattern and axial ratio pattern of the antenna 900 shown in Figure 25. Detailed Implementation

[0063] The technical solutions in this application will now be described with reference to the accompanying drawings.

[0064] The embodiments of this application are described in detail below, and examples of these embodiments are illustrated in the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0065] In the description of this application, it should be understood that the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0066] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between the components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0067] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. In the description of this application, it should be understood that the terms “center,” “longitudinal,” “lateral,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0068] To facilitate understanding of the embodiments of this application, the terminology involved in this application will be introduced below.

[0069] Antenna isolation: This refers to the ratio of the signal received by one antenna through another to the signal received by the transmitting antenna. Isolation is a physical quantity used to measure the degree of mutual coupling between antennas. The greater the isolation between antennas, the less mutual coupling they have; conversely, the smaller the isolation, the greater the mutual coupling. Antenna isolation depends on factors such as the antenna radiation pattern, the spatial distance between antennas, and the antenna gain.

[0070] Antenna return loss: This can be understood as the ratio of the signal power reflected back to the antenna port after passing through the antenna circuit to the transmit power at the antenna port. The smaller the reflected signal, the larger the signal radiated into space through the antenna, and the higher the antenna's radiation efficiency. Conversely, the larger the reflected signal, the smaller the signal radiated into space through the antenna, and the lower the antenna's radiation efficiency.

[0071] Antenna return loss can be represented by the S11 parameter, which is one of the S-parameters. S11 represents the reflection coefficient, and this parameter characterizes the antenna's transmission efficiency. The S11 parameter is usually negative. The smaller the S11 parameter, the smaller the antenna return loss, the less energy the antenna reflects back, which means more energy actually enters the antenna, and the higher the antenna's system efficiency. Conversely, the larger the S11 parameter, the greater the antenna return loss, and the lower the antenna's system efficiency.

[0072] It should be noted that in engineering, an S11 value of -6dB is generally used as the standard. When the S11 value of an antenna is less than -6dB, it can be considered that the antenna can work normally or that the antenna has good transmission efficiency.

[0073] Antenna polarization: At a given point in space, the electric field intensity E (vector) is a function of time t. As time progresses, the endpoint of the vector periodically traces a trajectory in space. If this trajectory is a straight line and perpendicular to the ground, it is called vertical polarization; if it is horizontal to the ground, it is called horizontal polarization. If the trajectory is elliptical or circular, and when viewed along the propagation direction, it rotates clockwise or right-handed with time, it is called right-hand circular polarization (RHCP); if it rotates counterclockwise or left-handed with time, it is called left-hand circular polarization (LHCP).

[0074] Radiation pattern: The distribution of the electromagnetic field radiated by the antenna on a sphere with a radius of a certain distance from the antenna, as a function of spatial angles (including azimuth and elevation).

[0075] E-plane: Abbreviated as E-plane, it is the electric field plane, a plane parallel to the direction of electric field propagation. It can also be described as the tangent between the antenna's maximum radiation direction and the electric field level. It is mainly used to describe the antenna's radiation characteristics in the direction of the electric field.

[0076] H-plane: Abbreviated as H-plane, it is the magnetic field plane, a plane parallel to the direction of magnetic field propagation. It can also be described as the tangent between the antenna's maximum radiation direction and the horizontal magnetic field. It is perpendicular to the E-plane and is mainly used to describe the antenna's radiation characteristics in the direction of the magnetic field.

[0077] Axial ratio (AR) of an antenna: In circular polarization, the trajectory traced periodically by the endpoints of the electric field vector in space is an ellipse. The ratio of the major axis to the minor axis of the ellipse is called the axial ratio. Axial ratio is an important performance indicator of a circularly polarized antenna, representing the purity of circular polarization and serving as a crucial metric for measuring the overall signal gain difference of the antenna in different directions. The closer the axial ratio value of an antenna is to 1 (the trajectory traced periodically by the endpoints of the electric field vector in space is a circle), the better its circular polarization performance. An axial ratio zero point can be the point where the antenna's axial ratio value is lowest within the operating frequency band. Within the operating frequency band, there can be one or more axial ratio zero points.

[0078] Low-profile antenna: This can refer to an antenna whose total height is less than the wavelength corresponding to its operating frequency band.

[0079] Wavelength: or operating wavelength, which can be the wavelength corresponding to the center frequency of the resonant frequency or the center frequency of the operating frequency band supported by the antenna. For example, assuming the center frequency of the B1 uplink band (resonant frequency of 1920MHz to 1980MHz) is 1955MHz, then the operating wavelength can be calculated using this frequency of 1955MHz.

[0080] It should be understood that the wavelength corresponding to the antenna's operating frequency band can be understood as the wavelength corresponding to the center frequency of the antenna's operating frequency band, or it can be understood as the wavelength corresponding to the antenna's resonant frequency.

[0081] The antenna provided in this application embodiment is applicable to electronic devices employing one or more of the following communication technologies: Bluetooth (BT) communication technology, Global Positioning System (GPS) communication technology, Wireless Fidelity (WiFi) communication technology, Global System for Mobile Communications (GSM) communication technology, Wideband Code Division Multiple Access (WCDMA) communication technology, Long Term Evolution (LTE) communication technology, 5G communication technology, and future communication networks. The electronic devices in this application embodiment can be mobile phones, tablets, laptops, smart bracelets, smartwatches, smart helmets, smart glasses, etc. The electronic device can also be a cellular phone, cordless phone, session initiation protocol (SIP) phone, wireless local loop (WLL) station, personal digital assistant (PDA), handheld device with wireless communication capabilities, computing device or other processing device connected to a wireless modem, in-vehicle device, electronic device in a 5G network, or electronic device in a future evolved public land mobile network (PLMN), etc., and this application embodiment is not limited thereto. Figure 1 exemplarily illustrates an electronic device provided in an embodiment of this application, using a mobile phone as an example for illustration.

[0082] As shown in Figure 1, the electronic device 1 may include: a cover 13, a display / module 15, a printed circuit board (PCB) 17, a middle frame 19, and a rear cover 21. It should be understood that in some embodiments, the cover 13 may be a glass cover, but it may also be replaced with a cover made of other materials, such as an ultra-thin glass cover, a PET (polyethylene terephthalate) cover, etc.

[0083] The cover plate 13 can be set close to the display module 15, and can be mainly used to protect the display module 15 from dust.

[0084] In one embodiment, the display module 15 may include a liquid crystal display (LCD), a light emitting diode (LED) display panel, or an organic light-emitting diode (OLED) display panel, etc., and this application does not limit it.

[0085] The mid-frame 19 primarily serves to support the entire device. Figure 1 shows the PCB 17 positioned between the mid-frame 19 and the rear cover 21. It should be understood that in one embodiment, the PCB 17 may also be positioned between the mid-frame 19 and the display module 15; this application does not impose any limitations on this. The printed circuit board PCB 17 can be made of flame-retardant material (FR-4) dielectric substrate, Rogers dielectric substrate, or a hybrid dielectric substrate of Rogers and FR-4, etc. Here, FR-4 is a designation for a flame-retardant material grade, and Rogers dielectric substrate is a high-frequency board. Electronic components, such as radio frequency chips, are carried on the PCB 17. In one embodiment, a metal layer can be disposed on the printed circuit board PCB 17. This metal layer can be used for grounding the electronic components carried on the printed circuit board PCB 17, or for grounding other components, such as bracket antennas, frame antennas, etc. This metal layer can be called a ground plane, grounding plate, or grounding layer. In one embodiment, this metal layer can be formed by etching metal onto the surface of any dielectric substrate in the PCB 17. In one embodiment, the metal layer for grounding may be disposed on the printed circuit board PCB 17 near the middle frame 19. In one embodiment, the edge of the printed circuit board PCB 17 may be considered as the edge of its ground layer. In one embodiment, the metal middle frame 19 may also be used for grounding the aforementioned components. The electronic device 1 may also have other ground planes / grounding layers, as previously described, and will not be repeated here.

[0086] The electronic device 1 may also include a battery (not shown in the figure). The battery may be disposed between the middle frame 19 and the back cover 21, or between the middle frame 19 and the display module 15; this application does not impose any limitations on this. In some embodiments, the PCB 17 is divided into a motherboard and a daughterboard, and the battery may be disposed between the motherboard and the daughterboard. The motherboard may be disposed between the middle frame 19 and the upper edge of the battery, and the daughterboard may be disposed between the middle frame 19 and the lower edge of the battery.

[0087] The electronic device 1 may also include a frame 11, which may be formed of a conductive material such as metal. The frame 11 may be disposed between the display module 15 and the back cover 21 and extend circumferentially around the periphery of the electronic device 1. The frame 11 may have four sides surrounding the display module 15 to help secure the display module 15. In one implementation, the frame 11 made of metal can be directly used as the metal frame of the electronic device 1, forming a metal frame appearance, suitable for industrial design (ID). In another implementation, the outer surface of the frame 11 may also be made of a non-metallic material, such as a plastic frame, forming a non-metallic frame appearance, suitable for non-metallic ID.

[0088] The middle frame 19 may include the frame 11. The middle frame 19, including the frame 11, is a single unit that supports the electronic components in the device. The cover plate 13 and the rear cover 21 respectively cover the upper and lower edges of the frame to form the housing of the electronic device. In one embodiment, the cover plate 13, the rear cover 21, the frame 11, and / or the middle frame 19 may be collectively referred to as the housing of the electronic device 1. It should be understood that "housing" may refer to part or all of any one of the cover plate 13, the rear cover 21, the frame 11, or the middle frame 19, or to any combination of the cover plate 13, the rear cover 21, the frame 11, or the middle frame 19.

[0089] Alternatively, the frame 11 may not be considered part of the middle frame 19. In one embodiment, the frame 11 may be connected to and integrally formed with the middle frame 19. In another embodiment, the frame 11 may include inwardly extending protrusions to connect with the middle frame 19, for example, by means of spring clips, screws, welding, etc. The protrusions of the frame 11 can also be used to receive feed signals, so that at least a portion of the frame 11 acts as a radiator of the antenna to transmit / receive radio frequency signals. A gap 42 may exist between this portion of the frame acting as the radiator and the middle frame 19, thereby ensuring that the antenna radiator has a good radiation environment, enabling the antenna to have good signal transmission capabilities.

[0090] The back cover 21 can be made of metal or non-conductive material, such as glass or plastic.

[0091] Figure 1 only schematically shows some of the components included in the electronic device 1, and the actual shape, size and construction of these components are not limited by Figure 1.

[0092] Current terminal products, represented by smartphones, are trending towards thinner, lighter, smaller, and more multifunctional designs, requiring antennas to occupy increasingly less space while simultaneously meeting diverse communication needs. Ultra-low profile antennas (ULSAs) are those whose thickness or height is significantly smaller than the wavelength of the electromagnetic waves corresponding to their operating frequency band. Their design faces ever-increasing demands and presents significant challenges. Radiation efficiency refers to the ratio of energy radiated by the antenna to the energy received from the feed port. Higher radiation efficiency means that energy is radiated more effectively into free space. However, ULSAs are prone to exhibiting zero radiation efficiency within their operating frequency band, meaning that certain frequency bands will be inoperable in practical applications, posing a critical design challenge. Circularly polarized antennas, commonly used in mobile phone positioning systems, can avoid polarization mismatch caused by placement, greatly improving the stability of the positioning system. In summary, the integrated design of ULSAs—small in size, high in radiation efficiency, wide bandwidth, and circularly polarized—is both a crucial development requirement for terminals and presents significant design challenges.

[0093] In existing technologies, the main broadband circularly polarized antenna designs are as follows: 1. Circular polarization is achieved by feeding a single-layer patch antenna and chamfering the patch antenna. Parasitic strips are added around the patch to increase the axial ratio zero point and further improve the circular polarization bandwidth. However, when applied to low profiles, the circular polarization bandwidth is still insufficient. 2. Two axial ratio zero points of circular polarization are generated by coupling two different patch structures in the upper and lower layers. However, this also requires a high profile height and a large size. 3. The circular polarization bandwidth is improved by exciting a single-layer patch with a feed network with phase design. However, the overall size is still large. 4. A grid-like patch is fed by an L-shaped probe. However, the size is large at low profiles, making it difficult to meet the requirements of miniaturization.

[0094] To address the aforementioned problems, this application provides an antenna and an electronic device, which features low profile, miniaturization, and wide bandwidth.

[0095] For an ideal circularly polarized antenna, the two necessary conditions for generating circular polarization are a set of antenna elements with orthogonal polarization, the antenna elements radiating with approximately the same amplitude, and the antenna elements having a phase difference of approximately 90 degrees.

[0096] Taking a circularly polarized antenna operating in the ultra-wide band (UWB) as an example, the UWB operating frequency is generally 7987.2±499.2MHz, that is, the center frequency is 7987.2MHz.

[0097] Figure 2 is a schematic diagram of the structure of an antenna 100. The antenna 100 may include a substrate 110, a metal layer, and a radiator 120. The radiator 120 is disposed on the surface of the substrate 110. The substrate 110 is provided with an annular port, which is connected to the radiator 120 through a metal through-hole. Circular polarization is directly excited by single-ended feeding. The feed point of the antenna 100 is located at the non-center of the radiator 120, or in other words, the distance between the feed point of the antenna 100 and the central axis of symmetry of the radiator 120 is greater than 0. The antenna 100 excites two polarization modes of the radiator 120 through the bias design of the feed point: the horizontal polarization (HP) generated by the TM10 mode, representing the first polarization direction, and the vertical polarization (HP) generated by the TM01 mode. The polarization (VP) indicates the second polarization direction. The first polarization direction is orthogonal to the second polarization direction. Circular polarization characteristics are generated at the boundary between these two polarization modes. For ease of explanation, the first polarization direction can be represented by the x-direction and the second polarization direction can be represented by the y-direction in the following text. The thickness of the substrate 110 can be between 0.4 mm and 0.5 mm, for example, it can be 0.42 mm, 0.45 mm or 0.48 mm, etc.

[0098] In some possible implementations, the distance between the feed point of antenna 100 and the diagonal of radiator 120 is greater than 0.

[0099] It should be noted that the distance between the feed point of the antenna 100 and the diagonal of the radiator 120 is greater than 0, and the feed point is located in a non-central position of the radiator 120. By offsetting the feed point, the circular polarization mode of the radiator 120 can be excited. For example, the radiator 120 can be a rectangular microstrip patch, and the feed point is set in the area near the diagonal of the rectangular microstrip patch.

[0100] When the radiator 120 is a square microstrip patch, the feed point of the radiator 120 can be considered to fall approximately on the diagonal of the radiator 120 and not at the center of the radiator 120; when the radiator 120 is a rectangular microstrip patch, the distance between the feed point of the radiator 120 and the diagonal of the radiator 120 is greater than 0.

[0101] Figure 3 is a performance schematic diagram of the antenna 100 shown in Figure 2. In Figure 3(a), the S-parameters of the antenna 100 shown in Figure 2 are shown. In Figure 3(b), the impedance of the antenna 100 shown in Figure 2 is shown. In Figure 3(c), the axial ratio of the antenna 100 shown in Figure 2 is shown. In Figure 3(d), the radiation efficiency of the antenna 100 shown in Figure 2 is shown. In Figure 3(e), the maximum actual gain of the antenna 100 shown in Figure 2 is shown. It can be seen from Figure 3(c) that the antenna 100 has a clear axial ratio zero point, a narrow axial ratio bandwidth of about 70MHz, and a relatively flat radiation efficiency curve in the operating frequency band. It is a circularly polarized antenna with a low bandwidth.

[0102] Figure 4 shows an antenna 200 provided in an embodiment of this application. Compared with the antenna 100 shown in Figure 2, the antenna 200 further includes a first parasitic branch 231 and a second parasitic branch 232. The first parasitic branch 231 and the second parasitic branch 232 are respectively disposed at both ends of the radiator 220 in the first polarization direction. The first parasitic branch 231 and the second parasitic branch 232 partially overlap with the radiator 220 in the first polarization direction. The first parasitic branch 231 and the second parasitic branch 232 are centrally symmetrical with respect to the center of the radiator 220. The first parasitic branch 231 and the second parasitic branch 232 can be rectangular patches.

[0103] It should be understood that the length directions of the first parasitic segment 231 and the second parasitic segment 232 are perpendicular to the first polarization direction, so the first parasitic segment 231 and the second parasitic segment 232 can also be called vertical parasitic segments.

[0104] In some possible implementations, the length of the first parasitic branch ranges from 0.5 to 1.5 times the length of the radiator in the second polarization direction. Further, the length of the first parasitic branch ranges from 0.8 to 1.2 times the length of the radiator in the second polarization direction. For example, it can be 0.8, 0.9, 1, 1.1, or 1.2 times the length of the radiator in the second polarization direction.

[0105] The relevant characteristics of the second parasitic segment can be found in the description of the first parasitic segment, and will not be repeated here for the sake of brevity.

[0106] In some possible implementations, the number of first and second parasitic branches can be multiple and equal, or the first and second parasitic branches can be set in pairs.

[0107] Figure 5 is a performance schematic diagram of the antenna 200 shown in Figure 4. In Figure 5(a), the S-parameters of the antenna 200 are shown; in Figure 5(b), the impedance of the antenna 200 is shown; in Figure 5(c), the axial ratio of the antenna 200 is shown; in Figure 5(d), the radiation efficiency of the antenna 200 is shown; and in Figure 5(e), the maximum actual gain of the antenna 200 is shown. After adding the first parasitic stub 231 and the second parasitic stub 232, the antenna 200 generates additional VP polarization. The mode, together with the original two modes of radiator 220, can form two circularly polarized axial ratio zero points. The mode current is shown in the figure. The low-frequency band is the circular polarization formed by the current (VP) in the vertically distributed first parasitic stub 231 and the second parasitic stub 232 and the current (HP) of the horizontally distributed radiator 220. The high-frequency band is the circular polarization formed by the current (HP) of the horizontally distributed radiator 220 and the current (VP) of the vertically distributed radiator 220. The axial ratio bandwidth of antenna 200 is thus improved.

[0108] Figure 6 is a schematic diagram of the current distribution of the antenna 200 shown in Figure 4. As shown in Figure 6, there are two polarization modes coupled in the antenna 200. The first coupling mode is the coupling between the VP mode generated by the first parasitic stub 231 and the second parasitic stub 232 and the HP mode generated by the TM10 mode of the radiator 220. The second coupling mode is the coupling between the HP mode generated by the TM10 mode of the radiator 220 and the VP mode generated by the TM01 mode of the radiator 220.

[0109] After adding the first parasitic stub 231 and the second parasitic stub 232, the circular polarization bandwidth was improved by two zero axial ratio points, with an axial ratio bandwidth of approximately 140MHz. However, within the designed operating frequency band, a significant decrease in radiation efficiency occurred. Figure 7 is a schematic diagram of the current distribution of the antenna 200 shown in Figure 4. Referring to Figure 7, the reason for the decrease in radiation efficiency of the antenna 200 is explained. Within the operating frequency band, the radiation efficiency at 7.8GHz showed a significant decrease, which is represented by a dip in the radiation efficiency curve. The lowest point of the dip can be called the dip point, and the point where radiation efficiency decreases can be called the radiation efficiency dip point or radiation efficiency dip. The simulated current at this dip point is shown in Figure 7. It can be seen that the added first parasitic stub 231 and second parasitic stub 232 form a significant reverse current with the radiator 220, which cancels each other out. Therefore, the radiation efficiency of the antenna 200 decreases significantly. The formation of this radiation dip is due to the differential-mode coupling between the radiator 220 and the first parasitic stub 231 and the second parasitic stub 232, resulting in current cancellation.

[0110] Figure 8 is a schematic diagram of another antenna 300 provided in the embodiment of this application. The difference between antenna 300 and antenna 200 is that, in order to improve the situation of reduced radiation efficiency of antenna 200 in the operating frequency band, in the case that the first parasitic branch 331a and the second parasitic branch 332a have been provided at both ends of the radiator 320 respectively, the first parasitic branch 331b and the second parasitic branch 332b are also provided respectively.

[0111] It should be noted that the first parasitic branch 331a and the first parasitic branch 331b have the same related properties, and the first parasitic branch 331a and the first parasitic branch 331b completely overlap in the first polarization direction. In other words, the projection of the first parasitic branch 331b in the first polarization direction and the projection of the first parasitic branch 331a in the first polarization direction completely overlap.

[0112] Figure 9 is a performance schematic diagram of the antenna 300 shown in Figure 8. In Figure 9(a), the S-parameters of the antenna 300 shown in Figure 8 are shown; in Figure 9(b), the impedance of the antenna 300 shown in Figure 8 is shown; in Figure 9(c), the axial ratio of the antenna 300 shown in Figure 8 is shown; and in Figure 9(d), the radiation efficiency of the antenna 300 shown in Figure 8 is shown. It can be seen that compared with the antenna 200, the axial ratio bandwidth of the antenna 300 changes less, still about 140MHz. However, the radiation efficiency curve of the antenna 300 in the operating frequency band is relatively flat, and the concave point of the radiation efficiency is shifted outside the operating frequency band. In Figure 9(e), the maximum actual gain of the antenna 300 shown in Figure 8 is shown. The antenna 300 with this structure can still improve the axial ratio bandwidth through two circularly polarized axial ratio zeros. At the same time, the radiation efficiency of the antenna 300 in the operating frequency band does not decrease, thus improving the system efficiency and actual gain of the antenna 300.

[0113] As shown in Figure 9(d), the decrease in radiation efficiency occurs outside the operating frequency band. Compared with the radiation efficiency diagram of antenna 200 shown in Figure 4, the concave point of the radiation efficiency of antenna 300 has shifted from 7.8 GHz to 7.3 GHz, and the concave point of radiation efficiency has shifted from inside the operating frequency band to outside the operating frequency band.

[0114] Figures 10 and 11 are schematic diagrams of the current distribution of antenna 300 shown in Figure 8 at different operating frequencies. To further explain the principle of radiation efficiency dip transfer, Figure 10 shows the current distribution of antenna 300 at 7.8 GHz within the operating frequency band. It can be seen that within the operating frequency band, the currents between adjacent first parasitic stubs 331a and 331b of antenna 300 are in the same direction, and the currents between second parasitic stubs 332a and 332b are also in the same direction, forming common-mode coupling. Energy is transferred to the outermost first parasitic stubs 331b and 332b, and the original current cancellation weakens, thus filling the original radiation efficiency dip at 7.8 GHz. Figure 11 shows the current distribution of antenna 300 at 7.3 GHz outside the operating frequency band. The current distribution diagram shows that outside the operating frequency band, the currents between adjacent first parasitic stubs 331a and 331b are reversed, and the currents between second parasitic stubs 332a and 332b are also reversed, forming differential-mode coupling. There is strong current cancellation between two adjacent vertical parasitic stubs. However, the frequency of differential-mode coupling is outside the operating frequency band, so it will not affect the radiation efficiency of antenna 300 within the designed operating frequency band. This is manifested as the radiation efficiency pit shifting from within the operating frequency band to outside the operating frequency band. Furthermore, by adjusting the distance between two adjacent vertical parasitic stubs, for example, adjusting the distance between the first parasitic stubs 331a and 331b in the first polarization direction, the position of the radiation efficiency pit can be controlled.

[0115] Figure 12 shows another antenna 400 provided in this embodiment of the application. The difference between this antenna 400 and the antenna 300 shown in Figure 8 is that the antenna 400 further includes a third parasitic stub 433 and a fourth parasitic stub 434. The third parasitic stub 433 and the fourth parasitic stub 434 are respectively disposed at both ends of the second polarization direction of the radiator 420. The third parasitic stub 433 and the fourth parasitic stub 434 partially overlap with the radiator 420 in the second polarization direction. The third parasitic stub 433 and the fourth parasitic stub 434 are positioned relative to the radiator... The center of 420 is centrally symmetrical. The length of the third parasitic branch 433 is equal to the length of the fourth parasitic branch 434. The lengths of the third parasitic branch 433 and the fourth parasitic branch 434 are between 0.8 and 1.2 times the length of the radiator 420 in the second polarization direction, respectively. There can be multiple third parasitic branches 433 and fourth parasitic branches 434. For example, the antenna 400 includes third parasitic branches 433a and 433b, and fourth parasitic branches 434a and 434b.

[0116] In some possible implementations, the length of the third parasitic branch ranges from 0.5 to 1.5 times the length of the radiator in the first polarization direction. Further, the length of the third parasitic branch ranges from 0.8 to 1.2 times the length of the radiator in the first polarization direction. For example, it can be 0.8, 0.9, 1, 1.1, or 1.2 times the length of the radiator in the first polarization direction.

[0117] The characteristics of the fourth parasitic segment can be found in the description of the third parasitic segment, and will not be repeated here for the sake of brevity.

[0118] In some possible implementations, the number of third and fourth parasitic branches can be multiple and equal, or the third and fourth parasitic branches can be set in pairs.

[0119] In some possible implementations, when there are multiple first, second, third, and fourth parasitic segments in the antenna, the centers of adjacent parasitic segments can be connected. For example, the centers of two first parasitic segments can be connected. Other properties of the parasitic segments can be found in the descriptions of other embodiments of this application.

[0120] In some possible implementations, the number of the first, second, third, and fourth parasitic segments of the antenna can be three, four, five, or more, respectively. Other properties of the parasitic segments can be found in the descriptions of other embodiments of this application.

[0121] In some possible implementations, the radiator of the antenna is a square patch, and the diagonal of the square patch is cut off. Other properties of the parasitic branch can be found in the description of the embodiments of this application.

[0122] In some possible implementations, the radiator of the antenna is a circular patch, on which slots can be provided to achieve a circular polarization mode, and the parasitic stub is an arc-shaped parasitic stub. Other properties of the parasitic stub can be referred to the description in the embodiments of this application.

[0123] It should be noted that since the length directions of the third and fourth parasitic segments are horizontal to the first polarization direction, the third and fourth parasitic segments can also be called horizontal parasitic segments.

[0124] As shown in Figure 12, after adding the third parasitic branch 433 and the fourth parasitic branch 434 at both ends of the radiator 420 in the second polarization direction, an additional HP mode is added in the high-frequency band. The low-frequency band is the circular polarization formed by the vertically distributed current (VP) of the first parasitic branch 431 and the second parasitic branch 432 and the horizontally distributed current (HP) of the radiator 420. The high-frequency band is the circular polarization formed by the horizontally distributed current (HP) of the radiator 420 and the vertically distributed current (VP) of the radiator 420, as well as the circular polarization formed by the vertically distributed radiator current (VP) and the horizontally distributed current (HP) of the third parasitic branch 433 and the fourth parasitic branch 434.

[0125] Figure 13 is a performance schematic diagram of the antenna 400 shown in Figure 12. In Figure 13(a), the S-parameters of the antenna 400 shown in Figure 12 are shown; in Figure 13(b), the impedance of the antenna 400 shown in Figure 12 is shown; in Figure 13(c), the axial ratio of the antenna 400 shown in Figure 12 is shown; in Figure 13(d), the radiation efficiency of the antenna 400 shown in Figure 12 is shown; and in Figure 13(e), the maximum actual gain of the antenna 400 shown in Figure 12 is shown. Compared with the antenna 300 shown in Figure 8, the axial ratio bandwidth of the antenna 400 is further increased to approximately 230MHz. One more axial ratio zero point is added within the operating frequency band, resulting in a total of three axial ratio zero points. The radiation efficiency concave point of the antenna 400 also appears outside the operating frequency band, and the radiation efficiency curve within the operating frequency band is relatively flat, which is beneficial to improving the system efficiency and actual gain of the antenna 400.

[0126] Figure 14 shows the radiation pattern and axial ratio pattern of the antenna 400 shown in Figure 12 at different frequency points. Figure 14(a) is the radiation pattern of the antenna 400, and Figure 14(b) is the axial ratio pattern of the antenna 400. It can be seen that since the radiation efficiency pit is transferred outside the operating frequency band, the radiation pattern is basically consistent in the wide frequency band. The circular polarization gain is greater than 5.7 dBic, the beamwidth of 3 dB is ±39°, the cross polarization is <-15 dB, and the axial ratio in the axial ratio pattern is <3 dB within the beam range.

[0127] Figure 15 shows the current distribution of the antenna 400 shown in Figure 12 under different phases. For the same-direction current mode of the antenna 400 in the operating frequency band, that is, common-mode coupling, the current mode distribution under four different phases was analyzed at 90° intervals. As shown in Figure 15, the antenna 400 conforms to the right-hand circular polarization characteristic.

[0128] Figure 15 shows the current distribution at 0°, 90°, 180° and 270°, respectively. The current distribution rotates clockwise and satisfies the right-hand circular polarization characteristic.

[0129] Based on the above technical solution, by adding a pair of parasitic stubs at both ends of the first polarization direction of the antenna radiator, the effect of shifting the radiation efficiency pit from within the operating frequency band to outside the operating frequency band is achieved. By further adding a pair of parasitic stubs at both ends of the second polarization direction of the radiator, the axial ratio bandwidth of the antenna can be further increased, and the number of axial ratio zeros can be increased.

[0130] In some possible implementations, the position of the radiation efficiency concave point can be adjusted by adjusting the coupling distance between adjacent parasitic branches. The coupling distance between adjacent parasitic branches refers to the distance between the edges of adjacent parasitic branches.

[0131] Figure 16 is a schematic diagram of another antenna 500 provided in the embodiment of this application. The difference between it and the antenna 400 shown in Figure 12 is that the distance d1 between adjacent parasitic branches is different. For example, the distance between the second parasitic branch 532a and the second parasitic branch 532b in the first polarization direction is denoted as d1.

[0132] It should be noted that the distances between the first parasitic branch 531a and the first parasitic branch 531b, the second parasitic branch 532a and the second parasitic branch 532b, the third parasitic branch 533a and the third parasitic branch 533b, and the fourth parasitic branch 534a and the fourth parasitic branch 534b are all d1. Adjusting the distance between adjacent parasitic branches means that the distances between these four pairs of parasitic branches are adjusted simultaneously, and the adjusted values ​​are consistent.

[0133] Figure 17 is a performance schematic diagram of the antenna 500 shown in Figure 16. The distance d1 between adjacent parasitic stubs can be selected between 1% and 2% of the operating wavelength of the radiator 520. Further, it can be selected between 1.2% and 1.9% of the operating wavelength of the radiator 520. For example, d1 can be selected as 0.72 mm, 0.6 mm and 0.48 mm respectively to test the performance of the antenna 500. Among them, 0.72 mm corresponds to 1.9% of the operating wavelength, 0.6 mm corresponds to 1.6% of the operating wavelength and 0.48 mm corresponds to 1.2% of the operating wavelength. Figure 17(a) shows the S-parameters of the antenna 500 at these three distances. It can be seen that as the coupling distance decreases, the capacitive coupling between adjacent parasitic stubs becomes stronger and the differential mode shifts to the lower frequency band.

[0134] Figure 17(b) shows the radiation efficiency of antenna 500 at these three different distances. As the distance d1 between adjacent parasitic stubs decreases, the capacitive coupling between parasitic stubs is enhanced, and the differential mode coupling shifts to lower frequencies.

[0135] Adjusting the distance between the radiator and adjacent parasitic stubs also affects the antenna's radiation efficiency. Figure 18 is a schematic diagram of another antenna 600 provided in this embodiment of the application. The difference between this antenna 600 and the antenna 400 shown in Figure 12 is that the coupling distance between the radiator 620 and its adjacent parasitic stubs is d2. For example, the second parasitic stub 632a is one of the parasitic stubs adjacent to the radiator 620. The coupling distance between the second parasitic stub 632a and the radiator 620 in the first polarization direction is denoted as d2. The radiator 620 of the antenna 600 and its adjacent parasitic stubs... The distance between stalks refers to the distance between the edge of an adjacent parasitic stalk and the edge of the radiator. This distance can be selected between 1.5% and 3% of the operating wavelength of the radiator. More specifically, it can be selected between 1.75% and 2.8% of the operating wavelength of the radiator 620. For example, d2 is selected as 0.68mm, 0.85mm and 1.02mm for testing, where 0.68mm corresponds to 1.75% of the operating wavelength, 0.85mm corresponds to 2.2% of the operating wavelength and 1.02mm corresponds to 2.8% of the operating wavelength.

[0136] Figure 19 is a performance schematic diagram of the antenna 600 shown in Figure 18. Figure 19(a) shows the S-parameters of the antenna 600 at the three coupling distances. It can be seen that both excessively large and small coupling distances d2 will lead to increased return loss. When the coupling distance is 0.85 mm, the return loss of the antenna 600 is the lowest. Figure 19(b) shows the radiation efficiency of the antenna 600 at the three coupling distances. It can be seen that as the coupling distance decreases, the coupling between the radiator and the adjacent parasitic stubs becomes stronger. The location of the radiation efficiency pit of the antenna 600 does not change, and it always appears at 7.5 GHz. However, as the coupling distance d2 decreases, the fluctuation of radiation efficiency becomes stronger. When the coupling distance is 0.85 mm, the overall performance of the antenna 600 is relatively good.

[0137] It should be noted that the distances between the first parasitic branch 631a and the radiator 620, the second parasitic branch 632a and the radiator 620, the third parasitic branch 633a and the radiator 620, and the fourth parasitic branch 634a and the radiator 620 are all d2. Adjusting the distance between the parasitic branch and the radiator 620 means that the distances between these four parasitic branches and the radiator 620 are adjusted simultaneously, and the adjusted values ​​are consistent.

[0138] Figure 20 is a schematic diagram of another antenna 700 provided in an embodiment of this application.

[0139] Common-mode and differential-mode resonances between adjacent parasitic stubs also affect radiation efficiency within the operating frequency band. The distance between these resonances can be controlled by adjusting the offset between adjacent parasitic stubs. Taking the second parasitic stub 732a and 732b as an example, the offset distance between them refers to the length of the non-overlapping portion of their projections in the first polarization direction in the second polarization direction, denoted as d3. The offset distances for other parasitic stubs can be referenced from the description of the second parasitic stub. The value of d3 can be determined between 0 and 6% of the operating wavelength of the radiator 720, or further, between 0 and 5.5% of the operating wavelength of the radiator 720. When d3 is 0, it indicates that adjacent parasitic stubs are aligned; as d3 increases, the degree of offset between adjacent parasitic stubs increases.

[0140] It should be noted that the offset distances between the first parasitic nodes 731a and 731b, the second parasitic nodes 732a and 732b, the third parasitic nodes 733a and 733b, and the fourth parasitic nodes 734a and 734b are all d3. Adjusting the offset distances between adjacent parasitic nodes means that the offset distances between these four pairs of parasitic nodes are adjusted simultaneously, and the adjusted values ​​are consistent.

[0141] It should be noted that when the second parasitic branch 732a is projected onto the second parasitic branch 732b in the first polarization direction, the non-overlapping portion may include the non-overlapping portion of the first end and the non-overlapping portion of the second end of the second parasitic branch 732a, and the lengths of these two non-overlapping portions are equal, both being d3.

[0142] Figure 21 is a performance schematic diagram of the antenna 700 shown in Figure 20. As shown in Figure 21(a), the S-parameters of the antenna 700 are shown when the parasitic stubs are aligned, staggered, and further staggered, respectively, with corresponding d3 values ​​of 0, 1.92 mm, and 2.05 mm. Among them, 1.92 mm corresponds to 5% of the operating wavelength, and 2.05 mm corresponds to 5.5% of the operating wavelength. Figure 21(b) shows the radiation efficiency of the antenna 700 when the parasitic stubs are aligned, staggered, and further staggered. It can be seen that as the distance of the parasitic stubs being staggered increases, the influence of common-mode resonance decreases, while the influence of differential-mode resonance increases. The radiation efficiency fluctuation of the antenna 700 in the operating frequency band increases. The radiation efficiency dip of the antenna 700 moves towards the higher frequency band as the distance between adjacent parasitic stubs increases, which also indicates that the influence of common-mode resonance on the antenna 700 decreases, while the influence of differential-mode resonance on the antenna 700 increases. When adjacent parasitic stubs are aligned, that is, when d3 = 0, the performance of the antenna 700 is relatively good.

[0143] Figure 22 is a schematic diagram of another antenna 800 provided in an embodiment of this application. The difference between this antenna and antenna 400 lies in the different distances at which the parasitic stubs are offset from the radiator 820. Taking the second parasitic stub as an example, the second parasitic stubs 832a and 832b completely overlap in the first polarization direction. The length of the projection of the portion of the second parasitic stub 832a that does not overlap with the radiator 820 in the first polarization direction in the second polarization direction is denoted as d4, representing the distance at which the second parasitic stub 832a is offset from the radiator 820. The value of d4 can be determined between 0 and 6% of the operating wavelength of the radiator 820. Further, the value of d4 can be determined between 0 and 5.5% of the operating wavelength of the radiator 820.

[0144] It should be noted that the length of the projection of the part of the first parasitic branch 831a that does not overlap with the radiator 820 in the first polarization direction in the second polarization direction, the length of the projection of the part of the second parasitic branch 832a that does not overlap with the radiator 820 in the first polarization direction in the second polarization direction, the length of the projection of the part of the third parasitic branch 833a that does not overlap with the radiator 820 in the second polarization direction in the first polarization direction, and the length of the projection of the part of the fourth parasitic branch 834a that does not overlap with the radiator 820 in the second polarization direction in the first polarization direction in the first polarization direction are all d4. Adjusting the distance between the parasitic branches and the radiator 820 means that the distance between these four parasitic branches and the radiator 820 is adjusted simultaneously, and the adjusted values ​​are consistent.

[0145] Figure 23 is a performance schematic diagram of the antenna 800 shown in Figure 22. Figure 23(a) shows the S-parameter diagram of the antenna 800, with corresponding d4 values ​​of 0, 1.7 mm, and 2.1 mm, respectively. 1.7 mm corresponds to 4.5% of the operating wavelength, and 2.1 mm corresponds to 5.5% of the operating wavelength. When adjacent parasitic stubs are flush and the distance between the parasitic stubs and the radiator is offset, the effect on common-mode resonance is significant, while the effect on differential-mode resonance outside the operating frequency band is relatively small, as shown in Figure 23(b). As the distance between radiators increases, the amplitude and phase of common-mode coupling change, affecting the radiation efficiency within the operating frequency band, while having a smaller impact on differential-mode coupling. When the radiator is aligned with the parasitic stub, the radiation efficiency within the operating frequency band decreases significantly. When the radiator and the parasitic stub are offset by a certain distance, the radiation efficiency within the operating frequency band is relatively stable. However, when the offset distance is too large, the radiation efficiency will continue to decrease. When d4 is 1.7 mm, which is 4.5% of the operating wavelength of the radiator 820, the radiation efficiency of the antenna 800 is relatively good.

[0146] Figure 24 is a schematic diagram of the current distribution of the antenna 800 shown in Figure 22. Figures 24(a), (b), and (c) show the current distribution when the radiator is aligned with the parasitic stub, staggered, and further staggered, respectively. When the parasitic stub is aligned, i.e., when the value of d4 is 0, due to the axial symmetry of the parasitic stub in the antenna 800, it is impossible to excite the parasitic stub in the orthogonal direction. However, when the radiator 810 is staggered from the parasitic stub by a certain distance, i.e. when the value of d4 is not 0, energy can be coupled to the parasitic stub in the orthogonal direction, thereby transferring the radiative efficiency dip of the antenna 800 from within the operating frequency band to outside the operating frequency band.

[0147] Based on the above technical solution, by adding parasitic stubs at both ends of the first polarization direction and the second polarization direction of the radiator, the axial ratio zero point of the antenna can be increased while maintaining the stability of the radiation efficiency within the operating frequency band.

[0148] Increasing the number of parasitic stubs in an antenna can effectively adjust the antenna's radiation efficiency and the location of the pits. However, increasing the number of parasitic stubs also means increasing the antenna size, which is not conducive to antenna miniaturization.

[0149] Figure 25 is a schematic diagram of another antenna 900 provided in the embodiment of this application. Compared with antenna 400, the difference is that multiple capacitor pillars 940 are loaded on the edge inside the radiator 920. The capacitor pillars 940 can change the current distribution in the antenna 900, which can reduce the size of the antenna by 25%-35%. The reduction of 25%-35% means that the area of ​​the antenna 900 is reduced by 25%-35% compared with the area without capacitor pillars 940. For example, the area of ​​the antenna 900 is reduced by 35% compared with the area of ​​the antenna 400.

[0150] Figure 26 is a performance schematic diagram of the antenna 900 shown in Figure 25. Figure 26(a) is the S-parameter diagram of the antenna 900, Figure 26(b) is the impedance diagram of the antenna 900, Figure 26(c) is the axial ratio of the antenna 900, Figure 26(d) is the radiation efficiency of the antenna 900, and Figure 26(e) is the maximum actual gain of the antenna 900. The antenna 900 still has three axial ratio zeros in the operating frequency band, and the dip in the radiation efficiency of the antenna 900 has been transferred outside the operating frequency band. Due to the reduction in the overall size of the antenna 900, its radiation efficiency and circular polarization gain have decreased slightly.

[0151] Figure 27 shows the radiation pattern and axial ratio pattern of the antenna 900 shown in Figure 25 at different frequency points. Figure 27(a) is the radiation pattern of the antenna 900, and Figure 27(b) is the axial ratio pattern of the antenna 900. It can be seen that since the radiation efficiency pit of the antenna 900 is transferred outside the operating frequency band, the radiation pattern is basically consistent in the wide frequency band. The circular polarization gain is greater than 4.4 dBic, the beamwidth of 3 dB is ±40°, the cross polarization is <-15 dB, and the axial ratio in the axial ratio pattern is <3 dB within the beam range.

[0152] Based on the above technical solution, by setting capacitor pillars on the edge of the radiating body of the antenna, the circular polarization bandwidth of the antenna is increased and the radiation efficiency is improved, while the antenna is also miniaturized.

[0153] It is understandable that multiple capacitor pillars can be loaded along the edge of the radiating body in antennas 200, 300, 400, 500, 600, 700 or 800, thereby reducing the antenna area and achieving antenna miniaturization.

[0154] Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0155] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0156] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the mutual coupling, direct coupling, or communication connection shown or discussed may be through some interfaces; the direct coupling or communication connection between devices or units may be electrical or other forms.

[0157] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An antenna, characterized in that, include: substrate; A radiator is disposed on the surface of the substrate, and the distance between the feed point of the radiator and the central axis of symmetry of the radiator is greater than 0. First parasitic segment, second parasitic segment; The first parasitic branch and the second parasitic branch are respectively disposed on both sides of the radiator in the first polarization direction. The projections of the first parasitic branch and the second parasitic branch in the first polarization direction partially overlap with the radiator. The first parasitic branch and the second parasitic branch are centrally symmetrical with respect to the center of the radiator. The lengths of the first parasitic segment and the second parasitic segment are equal in the second polarization direction; The first polarization direction and the second polarization direction are orthogonal.

2. The antenna according to claim 1, characterized in that, The length of the first parasitic branch in the second polarization direction ranges from 0.8 to 1.2 times the length of the radiator.

3. The antenna according to claim 1 or 2, characterized in that, The number of the first parasitic segment and the number of the second parasitic segment are multiple and equal.

4. The antenna according to claim 3, characterized in that, In the plurality of first parasitic segments, the non-overlapping portion of the projection of the first parasitic segment and the adjacent first parasitic segment close to the radiator in the first polarization direction has the same length in the second polarization direction and is less than or equal to 5.5% of the operating wavelength of the radiator.

5. The antenna according to claim 3, characterized in that, The projections of the multiple first parasitic branches in the first polarization direction completely overlap.

6. The antenna according to claim 5, characterized in that, The length of the projection of the portion of the first parasitic branch that does not overlap with the radiator in the first polarization direction onto the second polarization direction is less than or equal to 5.5% of the operating wavelength of the radiator.

7. The antenna according to any one of claims 1-6, characterized in that, The distance between the first parasitic branch adjacent to the radiator and the radiator in the first polarization direction is greater than or equal to 1.75% of the operating wavelength of the radiator and less than or equal to 2.8% of the operating wavelength of the radiator.

8. The antenna according to any one of claims 3-7, characterized in that, The spacing between the plurality of first parasitic branches in the first polarization direction is equal and is greater than or equal to 1.2% and less than or equal to 1.9% of the operating wavelength of the radiator.

9. The antenna according to any one of claims 1-8, characterized in that, The antenna also includes: Third parasitic segment, fourth parasitic segment; The third parasitic branch and the fourth parasitic branch are respectively disposed on both sides of the radiator in the second polarization direction. The projections of the third parasitic branch and the fourth parasitic branch in the second polarization direction partially overlap with the radiator. The third parasitic branch and the fourth parasitic branch are centrally symmetrical with respect to the center of the radiator. The third parasitic segment and the fourth parasitic segment have the same length in the first polarization direction.

10. The antenna according to claim 9, characterized in that, The length of the third parasitic branch in the first polarization direction ranges from 0.8 to 1.2 times the length of the radiator.

11. The antenna according to claim 9 or 10, characterized in that, The number of the third parasitic segment and the fourth parasitic segment are multiple and equal.

12. The antenna according to claim 11, characterized in that, In the plurality of the third parasitic segments, the non-overlapping portion of the projection of the third parasitic segment and the adjacent third parasitic segment close to the radiator in the second polarization direction has the same length in the first polarization direction and is less than or equal to 5.5% of the operating wavelength of the radiator.

13. The antenna according to claim 11, characterized in that, The projections of the plurality of the third parasitic branches in the second polarization direction completely overlap.

14. The antenna according to claim 13, characterized in that, The length of the projection of the portion of the third parasitic branch that does not overlap with the radiator in the second polarization direction in the first polarization direction is less than or equal to 5.5% of the operating wavelength of the radiator.

15. The antenna according to any one of claims 9-14, characterized in that, The distance between the third parasitic branch adjacent to the radiator and the radiator in the second polarization direction is greater than or equal to 1.75% of the operating wavelength of the radiator and less than or equal to 2.8% of the operating wavelength of the radiator.

16. The antenna according to any one of claims 11-15, characterized in that, The spacing between the plurality of third parasitic branches in the second polarization direction is equal and is greater than or equal to 1.2% and less than or equal to 1.9% of the operating wavelength of the radiator.

17. The antenna according to any one of claims 1-16, characterized in that, The radiator is a rectangular radiator, and the first parasitic branch and the second parasitic branch are both rectangular parasitic branches. The distance between the feed point of the radiator and the diagonal of the radiator is greater than 0.

18. The antenna according to any one of claims 1-16, characterized in that, The radiator is a circular radiator, and the first parasitic segment and the second parasitic segment are arc-shaped parasitic segments.

19. The antenna according to any one of claims 1-18, characterized in that, Multiple capacitor pillars are arranged on the inner side of the radiator.

20. The antenna according to any one of claims 1-19, characterized in that, The thickness of the substrate is greater than or equal to 0.4 mm and less than or equal to 0.5 mm.

21. An electronic device, characterized in that, The electronic device includes an antenna as claimed in any one of claims 1-20.

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