Antenna structure and electronic device

Abstract

An antenna structure and an electronic device are provided, relating to the field of terminal technologies and the field of antenna technologies. The antenna structure includes a first antenna stub, a second antenna stub, a first matching circuit, and a second matching circuit, where the first antenna stub is connected to the second antenna stub; the second antenna stub includes a first port and a second port, the first port is grounded through the first matching circuit, the second port is grounded through the second matching circuit, the first matching circuit includes a first inductor, and the second matching circuit includes a second inductor; and the first antenna stub includes a third port, and the third port is configured to be connected to a first feed. According to the solution, a hand phantom efficiency reduction of an antenna is alleviated, and hand phantom efficiency of the antenna is improved. In this way, performance of the antenna is improved, and communication quality and user experience are ensured.

Description

[0001] This application claims priority to Chinese Patent Application No. 2023103739298, filed with the China National Intellectual Property Administration on March 29, 2023 and entitled "ANTENNA STRUCTURE AND ELECTRONIC DEVICE", which is incorporated herein by reference in its entirety.TECHNICAL FIELD

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

[0003] With the development of the 5th generation mobile communication technology (5th Generation Mobile Communication Technology, 5G) and the promotion of foldable screen devices, a quantity of antennas in a current electronic device gradually increases to support different mobile communication frequency bands and wireless communication frequency bands, and a requirement of a user on communication quality is higher.

[0004] Currently, some antennas of an electronic device that can be handheld, for example, a mobile phone or a tablet computer, are designed along perimeter border frames. When the electronic device is in a handheld state, blocked by a hand, transmission and reception of antenna signals are obstructed. Consequently, the antennas have a large hand phantom reduction, performance of the antennas is reduced, and communication quality and user experience are reduced.SUMMARY

[0005] To resolve the foregoing problem, this application provides an antenna structure and an electronic device, so that a hand phantom efficiency reduction of an antenna is alleviated and hand phantom efficiency of the antenna is improved. Therefore, performance of the antenna is improved, and communication quality and user experience are ensured.

[0006] According to a first aspect, this application provides an antenna structure. The antenna structure includes a first antenna stub, a second antenna stub, a first matching circuit, and a second matching circuit, where the first antenna stub is connected to the second antenna stub; the second antenna stub includes a first port and a second port, the first port is grounded through the first matching circuit, the second port is grounded through the second matching circuit, the first matching circuit includes a first inductor, and the second matching circuit includes a second inductor; and the first antenna stub includes a third port, and the third port is configured to be connected to a first feed.

[0007] In the antenna structure, a side that is provided with a port and to which a feed is connected is a first side, and another side opposite to the first side is a second side. When the antenna structure is used in an electronic device, the first side is the inside of the electronic device, and the second side is air outside the antenna structure. When a user holds the electronic device, a hand of the user is located on the second side, and there is a first interface between the first side and the second side. After the antenna structure is excited to generate an electric field, an electric field component perpendicular to the first interface is a normal component of the electric field, and an electric field component parallel to the first interface is a tangential component of the electric field. The normal component of the electric field penetrates the human body less, and brings a smaller hand phantom efficiency reduction. The tangential component of the electric field penetrates the human body more, and brings a larger hand phantom efficiency reduction. In this application, after the second antenna stub is added to the antenna structure and the two ports of the second antenna stub are grounded through the inductors, an electric field on a body of the first antenna stub can be reduced. In addition, a normal electric field is constructed at the second antenna stub. Because the normal electric field penetrates the human body less, an electric field penetrating the human body is reduced. Therefore, a hand phantom efficiency reduction of the antenna structure is reduced, antenna performance is improved, and communication quality and user experience are ensured.

[0008] In a possible implementation, the antenna structure includes a third matching circuit. The first antenna stub further includes a fourth port, the fourth port is grounded through the third matching circuit, and the third matching circuit includes a third inductor.

[0009] The third matching circuit is configured to perform filtering and adjust an operating frequency of the first antenna stub.

[0010] In a possible implementation, the antenna structure includes a third antenna stub, a first end of the third antenna stub is grounded, and a first gap exists between a second end of the third antenna stub and a first end of the first antenna stub. A second end of the first antenna stub is connected to a first end of the second antenna stub.

[0011] By disposing the third antenna stub, a reference ground of the antenna structure is lowered, and a normal electric field component is further increased, so that the hand phantom efficiency reduction of the antenna structure is further reduced.

[0012] In a possible implementation, a sum of a length of the third antenna stub and a length of the first antenna stub is a half of an operating wavelength of the first antenna stub.

[0013] In a possible implementation, the antenna structure further includes a third matching circuit. The first antenna stub further includes a fourth port. The fourth port is grounded through the third matching circuit, and the third matching circuit includes a third inductor.

[0014] In a possible implementation, a length of the first antenna stub is less than a quarter of an operating wavelength of the first antenna stub.

[0015] In a possible implementation, the antenna structure further includes a fourth matching circuit. The third antenna stub further includes a fifth port. The fifth port is grounded through the fourth matching circuit.

[0016] The fourth matching circuit can extract a portion of length from the third antenna stub to collectively form a split loop structure with the first antenna stub. In this way, a dual resonance may be generated in a middle band (Middle Band, MB) of an MHB frequency band, bandwidth is increased, and the hand phantom efficiency reduction is reduced.

[0017] In a possible implementation, a distance between the fifth port and the first gap is a quarter of an operating wavelength of the first antenna stub, and the fourth matching circuit is a zero-ohm resistance.

[0018] In a possible implementation, the antenna structure further includes a fifth matching circuit, and the third antenna stub further includes a sixth port. The sixth port is located between the fifth port and the first gap. The sixth port is grounded through the fifth matching circuit.

[0019] When the dual resonance is generated in the middle band of the MHB frequency band, a first resonance point of the dual resonance may be adjusted by using the fourth matching circuit and the fifth matching circuit. For example, a frequency of the first resonance point is adjusted by changing an inductance value of an inductor in the fourth matching circuit. A frequency of a second resonance point of the dual resonance can be adjusted by adjusting an inductance value of an inductor in the first matching circuit and an inductance value of an inductor in the second matching circuit.

[0020] In a possible implementation, the third antenna stub further includes a seventh port, and the seventh port is configured to be connected to a second feed. The third antenna stub is excited to act as an independent antenna, so that a frequency band supported by the antenna structure is expanded, and an integration level and practicability of the antenna structure are further improved.

[0021] In a possible implementation, the fourth matching circuit includes a first filter circuit, and the fifth matching circuit includes a second filter circuit. A filtering frequency of the first filter circuit is a first operating frequency of the first antenna stub. A filtering frequency of the second filter circuit is a second operating frequency of the first antenna stub.

[0022] The first filter circuit and the second filter circuit are disposed, so that an operating frequency band of the first antenna stub and an operating frequency band of the third antenna stub do not overlap, and isolation between feed ports of the two antenna stubs is ensured.

[0023] In a possible implementation, the first filter circuit includes a first filter capacitor and a first filter inductor that are connected in series. The second filter circuit includes a second filter capacitor and a second filter inductor that are connected in series.

[0024] In a possible implementation, the first port is further connected to a third feed. The second antenna stub is connected to a separate feed, so that the second antenna stub is excited to act as a separate antenna. In addition, isolation between the second antenna stub and the first antenna stub is ensured by using the first matching circuit, so that the frequency band supported by the antenna structure is expanded, and the integration level and the practicability of the antenna structure are further improved.

[0025] In a possible implementation, the first inductor, the second inductor, and an inductor of each matching circuit in this application may be separately a combination of one or more of the following: a distributed inductor, an inductor spring, or a lumped inductor.

[0026] In a possible implementation, the first antenna stub, the second antenna stub, and the third antenna stub may be specifically metal conductors, or may use another implementation, for example, may be steel sheets, flexible printed circuit (flexible printed circuit, FPC) antennas, printing direct structure (printing direct structure, PDS) antenna stubs, laser-direct-structuring (Laser-Direct-structuring, LDS) antenna stubs, or the like.

[0027] According to a second aspect, this application provides an electronic device, and the electronic device may be a non-foldable screen mobile phone, a foldable screen mobile phone, a wearable electronic device (for example, a smart watch), a tablet computer, or the like. The electronic device may include one or more antenna structures provided in the foregoing implementations. A left-hand phantom efficiency reduction of the antenna structure is reduced, a right-hand phantom efficiency reduction is also reduced, and left-hand phantom efficiency and right-hand phantom efficiency both are improved. Therefore, after the antenna structure is used, communication quality of the electronic device with hand phantom can be ensured, and user experience is improved.

[0028] In a possible implementation, border frames of the electronic device are sequentially a first short border frame, a first long border frame, a second short border frame, and a second long border frame. The electronic device includes one antenna structure. In this case, the antenna structure may be disposed at the first long border frame or the second long border frame.

[0029] In a possible implementation, the electronic device includes a plurality of antenna structures. In this case, the plurality of antenna structures may all be disposed at the first long border frame. Alternatively, the plurality of antenna structures may all be disposed at the second long border frame. Alternatively, a first part of the plurality of antenna structures are disposed at the first long border frame, and a remaining second part of the plurality of antenna structures are disposed at the second long border frame.BRIEF DESCRIPTION OF DRAWINGS

[0030] FIG. 1 is a schematic diagram 1 of a scenario according to this application; FIG. 2 is a schematic diagram 2 of a scenario according to this application; FIG. 3 is a schematic diagram of an antenna structure according to an embodiment of this application; FIG. 4 is a schematic diagram of another antenna structure according to an embodiment of this application; FIG. 5 is a schematic diagram 1 of a principle according to an embodiment of this application; FIG. 6 is a schematic diagram 1 of electric field distribution of an antenna structure according to an embodiment of this application; FIG. 7 is a schematic diagram 2 of electric field distribution of an antenna structure according to an embodiment of this application; FIG. 8 is a simulation diagram 1 of antenna efficiency according to an embodiment of this application; FIG. 9 is a simulation diagram 2 of antenna efficiency according to an embodiment of this application; FIG. 10 is a schematic diagram of still another antenna structure according to an embodiment of this application; FIG. 11 is a simulation diagram 1 of a resonance frequency of an antenna structure according to an embodiment of this application; FIG. 12 is a simulation diagram 2 of a resonance frequency of an antenna structure according to an embodiment of this application; FIG. 13 is a schematic diagram of yet another antenna structure according to an embodiment of this application; FIG. 14 is a simulation diagram 3 of a resonance frequency of an antenna structure according to an embodiment of this application; FIG. 15 is a schematic diagram of another antenna structure according to an embodiment of this application; FIG. 16 is a schematic diagram 3 of electric field distribution of an antenna structure according to an embodiment of this application; FIG. 17 is a schematic diagram 4 of electric field distribution of an antenna structure according to an embodiment of this application; FIG. 18 is a schematic diagram of still another antenna structure according to an embodiment of this application; FIG. 19 is an equivalent circuit diagram 1 of an antenna structure according to an embodiment of this application; FIG. 20 is a simulation diagram 4 of a resonance frequency of an antenna structure according to an embodiment of this application; FIG. 21 is a schematic diagram 5 of electric field distribution of an antenna structure according to an embodiment of this application; FIG. 22 is a simulation diagram 3 of antenna efficiency according to an embodiment of this application; FIG. 23 is a schematic diagram of still another antenna structure according to an embodiment of this application; FIG. 24 is an equivalent circuit diagram 2 of an antenna structure according to an embodiment of this application; FIG. 25 is a simulation diagram 5 of a resonance frequency of an antenna structure according to an embodiment of this application; FIG. 26 is a simulation diagram 4 of antenna efficiency according to an embodiment of this application; FIG. 27 is a schematic diagram of yet another antenna structure according to an embodiment of this application; FIG. 28 is an equivalent circuit diagram 3 of an antenna structure according to an embodiment of this application; FIG. 29 is a simulation diagram 6 of a resonance frequency of an antenna structure according to an embodiment of this application; FIG. 30 is a simulation diagram 5 of antenna efficiency according to an embodiment of this application; FIG. 31 is a schematic diagram of another antenna structure according to an embodiment of this application; FIG. 32 is a schematic diagram of an electronic device according to an embodiment of this application; and FIG. 33 is a schematic diagram of another electronic device according to an embodiment of this application. DESCRIPTION OF EMBODIMENTS

[0031] To enable a person skilled in the art to understand the solutions of this application more clearly, an application scenario of the technical solutions of this application is described below first.

[0032] It may be understood that orientations such as "up", "down", "left", and "right" in the following descriptions of this application are used in the accompanying drawings that need to be provided with reference to this application, merely for ease of description, and do not constitute a limitation on the technical solutions of this application.

[0033] This application does not specifically limit a type of an electronic device. The electronic device may be a non-foldable screen mobile phone, a foldable screen mobile phone, a wearable electronic device (for example, a smart watch), a tablet computer, or the like.

[0034] The following uses an example in which the electronic device is a non-foldable screen mobile phone for description.

[0035] Refer to FIG. 1 and FIG. 2 together. FIG. 1 is a schematic diagram 1 of a scenario according to this application. FIG. 2 is a schematic diagram 2 of a scenario according to this application.

[0036] When a user holds a mobile phone device 100 with the right hand 200, a signal transmitted or received by an antenna (not shown in the figure) disposed at the right border frame (which may also be referred to as a waist position of the mobile phone) of the mobile phone is blocked by the right hand. This causes a clear reduction of antenna efficiency.

[0037] When the user uses the left hand to hold the mobile phone 100, an end of a finger of the left hand of the user may be located at the right border frame. This also causes a reduction of the antenna efficiency to some extent.

[0038] A test is performed by using an example in which the antenna disposed at the right border frame of the mobile phone is a middle high band (Middle High Band, MHB) antenna, and an obtained situation of a hand phantom reduction of the antenna is shown in the following table.

[0039] In a typical division manner, an MHB covers 1.71 GHz to 2.7 GHz. An uplink frequency range of the B1 frequency band in the MHB frequency band is 1.920 GHz to 1.980 GHz, and a downlink frequency range of the B1 frequency band in the MHB frequency band is 2.110 GHz to 2.170 GHz. An uplink frequency range of the B3 frequency band in the MHB frequency band is 1.710 GHz to 1.785 GHz, and a downlink frequency range of the B3 frequency band in the MHB frequency band is 1.850 GHz to 1.880 GHz.

[0040] The free space (free space) is a concept of an electromagnetic theory, and refers to a theoretically perfect vacuum, to be specific, a vacuum that does not include any material.

[0041] It can be learned from the foregoing Table 1 that, the right-hand phantom reduction of the MHB antenna is greater than 6 dB, and the efficiency with right-hand phantom is poor. This reduces performance of the antenna, and reduces communication quality and user experience.

[0042] When the antenna is disposed at the left border frame, a principle in which holding the mobile phone with hand by the user causes the reduction of the antenna efficiency is similar. Details are not described herein again.

[0043] To resolve the foregoing problem, this application provides an antenna structure and an electronic device. A tangential electric field of the antenna structure is reduced, to reduce a hand phantom efficiency reduction of the antenna structure. In this way, antenna performance in a handheld state is improved, and communication quality and user experience are improved.

[0044] To enable a person skilled in the art to understand the solutions of this application more clearly, the technical solutions in embodiments of this application are described below with reference to the accompanying drawings in embodiments of this application.

[0045] Words such as "first" and "second" in the descriptions of this application are merely used for the purpose of description, and cannot be understood as indicating or implying relative significance or implicitly indicating a quantity of indicated technical features.

[0046] In this application, unless otherwise explicitly specified and defined, the term "connection" should be understood in a broad sense. For example, the "connection" may be a fixed connection, a detachable connection, or an integral connection. Alternatively, the "connection" may be a direct connection, or an indirect connection through an intermediary.

[0047] FIG. 3 is a schematic diagram of an antenna structure according to an embodiment of this application.

[0048] The antenna structure includes a first antenna stub 11, a second antenna stub 12, a first matching circuit 121, and a second matching circuit 122.

[0049] The first antenna stub 11 is connected to the second antenna stub 12. A width of the first antenna stub 11 and a width of the second antenna stub 12 are not specifically limited in this embodiment of this application. The first antenna stub 11 and the second antenna stub 12 may be designed to be of equal width. Alternatively, as shown in FIG. 3, the second antenna stub 12 may be narrowed.

[0050] The second antenna stub 12 includes a first port port1 and a second port port2. The first port port1 is grounded through the first matching circuit 121, and the second port port2 is grounded through the second matching circuit 122.

[0051] A stub 30 may be a stub of another antenna on an electronic device on which the antenna structure is disposed, or may be a metal border frame of the electronic device. This is not specifically limited in this embodiment of this application.

[0052] FIG. 4 is a schematic diagram of another antenna structure according to an embodiment of this application.

[0053] FIG. 4 shows an implementation in which a first matching circuit 121 is a first inductor L1, and a second matching circuit 122 is a second inductor L2. A first end of the first inductor L1 is connected to a first port port1, and a second end of the first inductor L1 is grounded. A first end of the second inductor L2 is connected to a second port port2, and a second end of the second inductor L2 is grounded.

[0054] A first antenna stub 11 includes a third port port3. The third port port3 is configured to be connected to a first feed feed1, to excite the antenna structure.

[0055] An operating principle of the antenna structure is described below by using an example in which the antenna structure operates in an MHB frequency band.

[0056] FIG. 5 is a schematic diagram 1 of a principle according to an embodiment of this application.

[0057] The left side of a first interface A is a first side of an antenna structure, namely, the inside of a mobile phone device 100, and a first antenna stub 11 is specifically an inverted-F antenna (Inverted-F antenna, IFA). The right side of the first interface A is a second side of the antenna structure.

[0058] There is air between the first interface A and a second interface B, and the right side of the second interface B is a human body, namely, the right hand 200.

[0059] When the antenna structure does not include a second antenna stub 12 in this application, an electric field is shown in a curve corresponding to E in the figure, and orthogonal decomposition is performed on electric field strength, to obtain a normal electric field and a tangential electric field.

[0060] The normal direction is perpendicular to the first interface A and perpendicular to the antenna stub 11, that is, is the X direction in the figure. The tangential direction is parallel to the second interface A and parallel to the antenna stub 11, that is, is the Y direction in the figure.

[0061] A permittivity of air is ε1, and a permeability of air is µ1. A permittivity of the human body is ε2, and a permeability of the human body is µ2. ε2 is much greater than ε1, and µ2 and µ1 are almost equal. A normal electric field in air is En1, and a normal electric field penetrating the human body is En2. The two fields satisfy the following formula: En 2 = ε 1 / ε 2 En 1

[0062] Because ε2 is much greater than ε1, it can be known from the formula (1) that in this case, En2 is much less than En1.

[0063] In a common mode (common mode, CM) of the antenna structure, a normal component of the electric field is abundant, a normal electric field penetrating the human body is small, an electromagnetic wave absorption rate (specific absorption rate, SAR) is low, and a hand phantom efficiency reduction is small.

[0064] A tangential electric field in air is Et1, and a tangential electric field penetrating the human body is Et2. When µ2 and µ1 are almost equal, Et1 and Et2 satisfy the following formula: Et 2 = Et 1

[0065] In a differential mode (differential mode, DM) of the antenna structure, a tangential component of the electric field is abundant, a tangential electric field penetrating the human body is large, a SAR is high, and a hand phantom efficiency reduction is large.

[0066] When operating at 1.9 GHz, the antenna shown in FIG. 5 is in the common mode, a right-hand phantom efficiency reduction may reach 6 dB, a left-hand phantom efficiency reduction may reach 4 dB, and a maximum value of the electric field may reach 95 dB (V / m).

[0067] FIG. 6 is a schematic diagram 1 of electric field distribution of an antenna structure according to an embodiment of this application.

[0068] An example in which inductance values of a first inductor L1 and a second inductor L2 are 3 nH is used. FIG. 6 shows an electric field distribution situation of the antenna structure when a resonance point is 1.82 GHz.

[0069] In the technical solutions provided in this application, a first antenna stub 11 may be considered as a conventional antenna stub. After a second antenna stub 12 is further added, and two ports of the second antenna stub 12 are grounded through an inductor, an electric field on a body of the first antenna stub 11 can be reduced. A maximum value of an electric field shown in the figure is 90.6598 dB (V / m), which is reduced compared with 95 dB (V / m) in the original solution. In addition, a normal electric field is constructed at the second antenna stub 12. Because the normal electric field penetrates the human body less, an electric field penetrating the human body is reduced. Therefore, a hand phantom efficiency reduction of the antenna structure is reduced.

[0070] FIG. 7 is a schematic diagram 2 of electric field distribution of an antenna structure according to an embodiment of this application.

[0071] An example in which inductance values of a first inductor L1 and a second inductor L2 are 3 nH is still used. FIG. 7 shows an electric field distribution situation of the antenna structure when a resonance point is 2.27 GHz.

[0072] A maximum value of an electric field is 88.8549 dB (V / m), which is reduced compared with 95 dB (V / m) in the original solution. A normal electric field is constructed at a second antenna stub 12. Because the normal electric field penetrates the human body less, an electric field penetrating the human body is reduced. Therefore, a hand phantom efficiency reduction of the antenna structure is reduced.

[0073] FIG. 8 is a simulation diagram 1 of antenna efficiency according to an embodiment of this application.

[0074] FIG. 8 further shows correspondences between some scattering parameters (Scatter Parameters, S-Parameters) and a frequency (Frequency). S1,1 represents an input return loss, and reflects an impedance matching situation of an antenna structure. A smaller value of S 1,1 is better.

[0075] Inductance values of L1 and L2 are 3 nH.

[0076] A curve S1,1 40 FS 1 3N numbered 1 represents a correspondence between a return loss in free space and the frequency.

[0077] A curve S1,1 40 HR 1 3N numbered 2 represents a correspondence between a return loss with right-hand phantom and the frequency.

[0078] A curve S1,1 40 HL 1 3N numbered 3 represents a correspondence between a return loss with left-hand phantom and the frequency.

[0079] A curve System Tot. Efficiency [AC1] 40 FS 1 3N numbered 4 represents a correspondence between efficiency in free space and the frequency.

[0080] A curve System Tot. Efficiency [AC1] 40 HR 1 3N numbered 5 represents a correspondence between efficiency with right-hand phantom and the frequency.

[0081] A curve System Tot. Efficiency [AC1] 40 HL 1 3N numbered 6 represents a correspondence between efficiency with left-hand phantom and the frequency.

[0082] It can be learned from the curves 1 to 3 that, before and after an inductor is loaded, S1,1 is all less than -12 dB when a resonance point is 1.8 GHz, satisfying an actual application requirement.

[0083] It can be learned from the curves 4 and 5 that, a left-hand phantom reduction of the antenna structure is approximately -1.909 dB-(-4.6245 dB)=2.7155 dB, and a right-hand phantom reduction of the antenna structure is approximately -1.909 dB-(-5.0165 dB)=3.1075 dB.

[0084] FIG. 9 is a simulation diagram 2 of antenna efficiency according to an embodiment of this application.

[0085] In FIG. 9, a curve System Tot. Efficiency [AC1]_chagngui FS numbered 4 represents a correspondence between efficiency in free space and a frequency in a case in which no inductor is disposed.

[0086] A curve System Tot. Efficiency [AC1] chagngui HL numbered 5 represents a correspondence between efficiency with left-hand phantom and the frequency in a case in which no inductor is disposed.

[0087] A curve System Tot. Efficiency [AC1] chagngui HR numbered 6 represents a correspondence between efficiency with right-hand phantom and the frequency in a case in which no inductor is disposed.

[0088] It can be learned that, compared with a conventional solution, in the solution of this application, bandwidth of an antenna structure is increased, a left-hand phantom efficiency reduction is reduced by about 1.2 dB, and a right-hand phantom efficiency reduction is reduced by about 3 dB.

[0089] FIG. 10 is a schematic diagram of still another antenna structure according to an embodiment of this application.

[0090] A difference between this antenna structure and the antenna structure shown in FIG. 3 is that this antenna structure further includes a third matching circuit 111.

[0091] A first antenna stub 11 includes a fourth port port4, and the fourth port port4 is grounded through the third matching circuit 111.

[0092] In some embodiments, the third matching circuit 111 includes a third inductor L3. The third matching circuit 111 is disposed at an end of the first antenna stub 11, namely, an end far away from a second antenna stub 12.

[0093] A resonance frequency of the antenna structure may be adjusted by changing inductance values of a first inductor L1, a second inductor L2, and the third inductor L3. Detailed descriptions are provided below.

[0094] FIG. 11 is a simulation diagram 1 of a resonance frequency of an antenna structure according to an embodiment of this application.

[0095] FIG. 11 is a simulation diagram when inductance values of a first inductor L1 and a second inductor L2 both are 3 nH, values of a third inductor L3 are sequentially 1 nH, 2 nH, 3 nH, 5 nH, 15 nH, and 20 nH, and a third matching circuit 111 is open-circuited to the ground.

[0096] Different inductance values are switched on the third matching circuit 111 of a first antenna stub 11, and a 2.2 GHz resonance point hardly shifts. However, as the inductance value of the third inductor L3 decreases, a current flowing to a second antenna stub 12 becomes weaker, and an improvement effect for a hand phantom reduction becomes worse.

[0097] Changing the inductance value of the third inductor L3 causes a low-frequency resonance to shift. As the inductance value of L3 increases, the resonance shifts to a lower frequency.

[0098] FIG. 12 is a simulation diagram 2 of a resonance frequency of an antenna structure according to an embodiment of this application.

[0099] FIG. 12 is a simulation diagram when a third matching circuit 111 is open-circuited to the ground, a first inductor L1 and a second inductor L2 have same values, and inductance values are sequentially 0, 1 nH, 2 nH, 3 nH, 4 nH, and 5 nH.

[0100] It can be learned that when the inductance values of the first inductor L1 and the second inductor L2 change, a low-frequency resonance hardly shifts, and a resonance point at a high frequency around 2.2 GHz shifts to a lower frequency as the inductance value increases.

[0101] With reference to FIG. 11 and FIG. 12, in actual application, a function of the first inductor L1, the second inductor L2, and a third inductor L2 is selecting a proper inductance value to enable the antenna structure to have two resonance points in an MHB frequency band. For example, coverage of a B1 frequency band and a B2 frequency band may be implemented.

[0102] In addition, a length L1 of a first antenna stub 11 and / or a length L2 of a second antenna stub 12 may be adjusted, to further adjust a hand phantom efficiency reduction of an antenna. Detailed descriptions are provided below.

[0103] An example in which L1 is 21 mm and the length of L2 is changed is used for description. Table 2: Relationship between L2 and a right-hand phantom efficiency reduction L2 (mm)26262121161666Inductance values of L1 and L2 (nH)03355558Right-hand phantom efficiency reduction (dB)5.93.643333.32.6

[0104] It may be learned from Table 2 that, as the loaded inductance values of L1 and L2 increase, the hand phantom efficiency reduction of the antenna structure decreases.

[0105] When the inductance values of L1 and L2 are small, the hand phantom efficiency reduction increases as the length L2 of the second antenna stub 12 decreases.

[0106] When the inductance values of L1 and L2 are large, the hand phantom efficiency reduction is mainly affected by a magnitude of the inductance value. A larger loaded inductance value indicates a smaller hand phantom reduction.

[0107] In conclusion, according to the antenna structure provided in this embodiment of this application, after the second antenna stub is added and two ports of the second antenna stub are grounded through the inductors, an electric field on a body of the first antenna stub can be reduced. In addition, a normal electric field is constructed at the second antenna stub. Because the normal electric field penetrates the human body less, an electric field penetrating the human body is reduced. Therefore, the hand phantom efficiency reduction of the antenna structure is reduced.

[0108] This application further provides another implementation of the antenna structure. A third antenna stub is added to further increase a normal electric field component, to reduce the hand phantom efficiency reduction. Detailed descriptions are provided below with reference to the accompanying drawings.

[0109] FIG. 13 is a schematic diagram of yet another antenna structure according to an embodiment of this application.

[0110] The antenna structure includes a first antenna stub 11, a second antenna stub 12, a third antenna stub 13, a first matching circuit 121, a second matching circuit 122, and a third matching circuit 111.

[0111] A second end of the first antenna stub 11 is connected to the second antenna stub 12.

[0112] The first antenna stub 11 is connected to the second antenna stub 12.

[0113] The second antenna stub 12 includes a first port port1 and a second port port2. The first port port1 is grounded through the first matching circuit 121, and the second port port2 is grounded through the second matching circuit 122.

[0114] The first antenna stub 11 includes a third port port3 and a fourth port port4. The third port port3 is grounded, and the fourth port port4 is grounded through the third matching circuit 111.

[0115] A resonance frequency of the antenna structure may be adjusted by changing inductance values of a first inductor L1, a second inductor L2, and a third inductor L3.

[0116] A first end of the third antenna stub 13 is grounded, and a first gap 14 exists between a second end of the third antenna stub 13 and a first end of the first antenna stub 11, so that the third antenna stub 13 can be excited.

[0117] A length of the third antenna stub 13 is L3, and a principle of this embodiment is described below.

[0118] FIG. 14 is a simulation diagram 3 of a resonance frequency of an antenna structure according to an embodiment of this application.

[0119] In FIG. 14, lengths of L3 corresponding to curves numbered 1 to 5 are respectively 40 mm, 30 mm, 20 mm, 10 mm, and 0 mm.

[0120] It can be learned that as the length of L3 gradually decreases, two resonance frequencies of the antenna structure both shift to the right correspondingly.

[0121] When the length of L3 is 0 mm, it may be considered that a third antenna stub is directly grounded at a first gap 14. For a schematic diagram of the antenna structure in this case, refer to FIG. 15. In this case, a resonance of the curve numbered 5 at 2 GHz is in a common mode, and as the length of L3 increases, a differential mode of the antenna gradually decreases. When the length of L3 is 40 mm, the 2 GHz resonance changes to a differential mode of a slot.

[0122] FIG. 16 is a schematic diagram 3 of electric field distribution of an antenna structure according to an embodiment of this application.

[0123] In this case, a length of L3 is 0 mm, an area A in the figure is a handheld part outside the antenna structure, and an area B is the inside of the antenna structure. It can be learned that, in this case, because there is a first gap 14, a reference ground is lifted, and an original normal electric field is changed to a tangential electric field in the area A, namely, a horizontal electric field in the figure. Consequently, a hand phantom reduction increases.

[0124] FIG. 17 is a schematic diagram 4 of electric field distribution of an antenna structure according to an embodiment of this application.

[0125] FIG. 17 shows electric field distribution when a length of L3 is 40 mm. A resonance of a B1 frequency band is converted from a common mode of a slot into a differential mode of an asymmetric slot by disposing a third antenna stub L3, so that a tangential component of an electric field is reduced, and an electric field outside the antenna is reduced. An area A in FIG. 17 is compared with the area A in FIG. 16, and it may be found that the tangential component of the electric field in the area A in FIG. 17 is significantly reduced, so that a hand phantom efficiency reduction is reduced.

[0126] In some embodiments, when the third matching circuit in FIG. 13 is not disposed, a sum of the length of the third antenna stub 13 and a length of a first antenna stub 11 is a half of an operating wavelength of the first antenna stub 11. Further, the length of the third antenna stub 13 and the length of the first antenna stub 11 may be separately a quarter of the operating wavelength of the first antenna stub 11.

[0127] In some other embodiments, when the third matching circuit in FIG. 13 is disposed, because the third matching circuit has an adjusting function on a resonance frequency, in this case, the length of the first antenna stub 11 is less than a quarter of the operating wavelength of the first antenna stub. In other words, in this case, the sum of the length of the third antenna stub 13 and the length of the first antenna stub 11 is less than a half of the operating wavelength of the first antenna stub 11.

[0128] Specific forms of the first antenna stub 11, the second antenna stub 12, and the third antenna stub 13 in this embodiment of this application may be metal conductors shown in the figure, or may use another implementation, for example, may be steel sheets, flexible printed circuit (flexible printed circuit, FPC) antennas, printing direct structure (printing direct structure, PDS) antenna stubs, laser-direct-structuring (Laser-Direct-structuring, LDS) antenna stubs, or the like. Details are not described again in this embodiment of this application.

[0129] When the length of the third antenna stub 13 is fixed, an inband mode of the antenna structure may be changed by disposing a matching circuit on the third antenna stub 13. Detailed descriptions are provided below.

[0130] FIG. 18 is a schematic diagram of still another antenna structure according to an embodiment of this application.

[0131] The antenna structure shown in the figure further includes a fourth matching circuit 131 and a fifth matching circuit 132, and a third antenna stub 13 includes a fifth port port5 and a sixth port port6.

[0132] The fifth port port5 is grounded through the fourth matching circuit 131, and the sixth port port6 is grounded through the fifth matching circuit 132. The sixth port port6 is located between the fifth port port5 and a first gap 14.

[0133] In a possible implementation, the fourth matching circuit 131 includes a zero-ohm resistance, and the fifth port port5 is grounded through the zero-ohm resistance. The fifth matching circuit 132 is open-circuited, in other words, impedance of the fifth matching circuit 132 is infinite.

[0134] In this case, a function of the fourth matching circuit 131 is to extract a portion of length from the third antenna stub 13 to collectively form a split loop (loop) structure with a first antenna stub. In this way, a dual resonance may be generated in a middle band (Middle Band, MB) of an MHB frequency band, bandwidth is increased, and a hand phantom efficiency reduction is reduced. In this case, a distance between the fifth port port5 and the first gap 14 may be a quarter of an operating wavelength of the first antenna stub 11.

[0135] The following describes technical effects of the technical solutions of this application through a simulation test.

[0136] FIG. 19 is an equivalent circuit diagram 1 of an antenna structure according to an embodiment of this application.

[0137] A first matching circuit 121 of the antenna structure includes an inductor L1, a second matching circuit 122 includes an inductor L2, and inductance values of L1 and L2 both are 3 nH. A third matching circuit 111 is open-circuited. A fourth matching circuit 131 is a zero-ohm resistance. A fifth matching circuit 132 is open-circuited. A port3 is connected to a first feed feed1 through a 4.3 pF capacitor and is grounded through a 4.3 nH inductor.

[0138] FIG. 20 is a simulation diagram 4 of a resonance frequency of an antenna structure according to an embodiment of this application.

[0139] A curve S1,1 FS example 2 numbered 1 represents a correspondence between efficiency in a case in which the antenna structure in FIG. 18 is in free space and a frequency.

[0140] A curve System Rad. Efficiency [AC1] FS example 2 numbered 2 represents a correspondence between radiation efficiency in a case in which the antenna structure in FIG. 18 is in free space and the frequency, where the radiation efficiency is radiated power / (input power-port reflected power).

[0141] A curve System Tot. Efficiency [AC1] FS example 2 numbered 3 represents a correspondence between efficiency in a case in which the antenna structure in FIG. 18 is in free space and the frequency, where the efficiency is radiated power / input power.

[0142] It can be learned from S1,1 FS that, in this case, a dual resonance is generated in an MB frequency band of an MHB frequency band, and two resonance points are a first resonance point 1.9482 GHz and a second resonance point 2.296 GHz. In this way, bandwidth of the middle band is increased, and middle band performance of the antenna structure is improved.

[0143] The first resonance point may be adjusted by using a fourth matching circuit 131 and a fifth matching circuit 132. For example, a frequency of the first resonance point is adjusted by changing an inductance value of an inductor in the fourth matching circuit 131. For another example, the fifth matching circuit 132 is not implemented by using an open circuit, but is also disposed with an inductor, so that a sixth port port6 is grounded through the inductor, to adjust the frequency of the first resonance point.

[0144] A frequency of the second resonance point can be adjusted by adjusting an inductance value of an inductor in a first matching circuit 121 and an inductance value of an inductor in a second matching circuit 122.

[0145] FIG. 21 is a schematic diagram 5 of electric field distribution of an antenna structure according to an embodiment of this application.

[0146] An area A in the figure is a handheld part outside the antenna structure, and an area B is the inside of the antenna structure. It can be learned that, a fourth matching circuit is disposed to extract a portion of length from a third antenna stub 13 to collectively form a split loop (loop) structure with a first antenna stub. In this way, an electric field in an area B inside the antenna structure is increased, and a normal electric field component is increased, so that a hand phantom efficiency reduction is reduced.

[0147] FIG. 22 is a simulation diagram 3 of antenna efficiency according to an embodiment of this application.

[0148] A curve System Tot. Efficiency [AC1] FS example 2 numbered 1 represents a correspondence between efficiency of the antenna structure in FIG. 18 in free space and a frequency.

[0149] A curve System Tot. Efficiency [AC1]_HL example 2 numbered 2 represents a correspondence between efficiency of the antenna structure in FIG. 18 with left-hand phantom and the frequency.

[0150] A curve System Tot. Efficiency [AC1]_H example 2 numbered 3 represents a correspondence between efficiency of the antenna structure in FIG. 18 with right-hand phantom and the frequency.

[0151] A curve System Tot. Efficiency [AC1]_chagngui FS numbered 4 represents a correspondence between efficiency of a conventional antenna structure in free space and the frequency. The conventional antenna structure is an antenna structure that does not include a second antenna stub or a third antenna stub.

[0152] A curve System Tot. Efficiency [AC1] chagngui HL numbered 5 represents a correspondence between efficiency of the conventional antenna structure with left-hand phantom and the frequency.

[0153] A curve System Tot. Efficiency [AC1] chagngui HR numbered 6 represents a correspondence between efficiency of the conventional antenna structure with right-hand phantom and the frequency.

[0154] It may be found from the curves 1 and 3 in FIG. 22 that, at 2 GHz, a left-hand phantom efficiency reduction of the antenna structure of this embodiment and a right-hand phantom efficiency reduction of the antenna structure of this embodiment both are only approximately 1 dB, and the reduction is significantly reduced.

[0155] In addition, in an MHB frequency band, in comparison with a solution of a conventional antenna, in this embodiment, the left-hand phantom efficiency reduction is reduced by approximately 2.3 dB, and the right-hand phantom efficiency reduction is reduced by approximately 4.5 dB. In other words, the hand phantom efficiency reduction is desirably alleviated, so that performance of the antenna structure is improved.

[0156] In addition, in the MHB frequency band, the curve 2 is higher than the curve 5 and the curve 3 is higher than the curve 6 in FIG. 22. It indicates that the antenna structure of this embodiment not only can reduce the hand phantom efficiency reduction, but also improves hand phantom efficiency of the antenna structure in the MHB frequency band.

[0157] In the foregoing embodiment, an example in which a fifth matching circuit 132 is open-circuited is used for description. In some other embodiments, the fifth matching circuit 132 may alternatively be provided with an inductor, so that a sixth port port6 is grounded through the inductor. In this case, the distance between a fifth port port5 and a first gap 14 may be less than a quarter of an operating wavelength of a first antenna stub 11.

[0158] In conclusion, according to the antenna structure provided in this embodiment of this application, the second antenna stub is added to the conventional antenna structure, and two ports of the second antenna stub are grounded through inductors, so that an electric field on a body of the first antenna stub can be reduced. In addition, a normal electric field is constructed at the second antenna stub. Because the normal electric field penetrates the human body less, an electric field penetrating the human body is reduced. Therefore, the hand phantom efficiency reduction of the antenna structure is reduced. In addition, the third antenna stub is further disposed, so that a reference ground of the antenna structure is lowered, and a normal electric field component is further increased. Therefore, the hand phantom efficiency reduction of the antenna structure is further reduced.

[0159] In some other embodiments, the third antenna stub is also connected to a feed, and is excited to act as an antenna. Detailed descriptions are provided below with reference to the accompanying drawings.

[0160] FIG. 23 is a schematic diagram of still another antenna structure according to an embodiment of this application.

[0161] A difference between the antenna structure shown in FIG. 23 and the antenna structure shown in FIG. 18 is that a third antenna stub 13 further includes a seventh port port7. The seventh port port7 is configured to be connected to a second feed feed2, to excite the third antenna stub 13 to act as an antenna.

[0162] In actual application, the third antenna stub 13 acts as an antenna, and an operating frequency band of the third antenna stub 13 and an operating frequency band of a first antenna stub 11 do not overlap. In this case, in the antenna structure provided in this embodiment of this application, the operating frequency band of the first antenna stub 11 and the operating frequency band of the third antenna stub 13 are different, that is, two antennas are integrated. This improves an integration level of the antenna structure.

[0163] Filtering between the third antenna stub 13 and the first antenna stub 11 is performed through an LC filter circuit, to improve isolation between the two antennas.

[0164] Specifically, in this case, a fourth matching circuit 131 includes a first filter circuit, and a filtering frequency of the first filter circuit is a first operating frequency of the first antenna stub 11.

[0165] A fifth matching circuit 132 includes a second filter circuit, and a filtering frequency of the second filter circuit is a second operating frequency of the first antenna stub 11.

[0166] The first filter circuit and the second filter circuit are disposed, so that the operating frequency band of the first antenna stub 11 and the operating frequency band of the third antenna stub 13 do not overlap.

[0167] Technical effects of this embodiment are described below with reference to a simulation test.

[0168] FIG. 24 is an equivalent circuit diagram 2 of an antenna structure according to an embodiment of this application.

[0169] A first filter circuit included in a fourth matching circuit 131 is specifically a first filter capacitor and a first filter inductor that are connected in series, where a capacitance value of the first filter capacitor is 0.6 pF, and an inductance value of the first filter inductor is 20 nH. In this case, the fourth matching circuit 131 is configured to perform filtering at 1.4 GHz.

[0170] A second filter circuit included in a fifth matching circuit 132 is specifically a second filter capacitor and a second filter inductor that are connected in series, where a capacitance value of the first filter capacitor is 0.5 pF, and an inductance value of the first filter inductor is 10 nH. In this case, the fifth matching circuit 132 is configured to perform filtering at 2.2 GHz.

[0171] An inductor of a first matching circuit 121 and an inductor of a second matching circuit 122 both are 3 nH. An inductor of a third matching circuit 111 is 10 nH. When a third port port3 is connected to a first feed feed1, the third port port3 is connected in parallel to a 5.1 nH inductor. When a seventh port port7 is connected to a second feed feed2, the seventh port port7 is connected in parallel to a 0.5 pF capacitor.

[0172] The antenna structure shown in FIG. 24 is simulated, and a simulation result is as follows.

[0173] FIG. 25 is a simulation diagram 5 of a resonance frequency of an antenna structure according to an embodiment of this application.

[0174] A curve S1,1 FS 1 instance 3 numbered 1 in FIG. 25 represents a correspondence between a return loss of a third port port3 in free space and a frequency.

[0175] A curve S1,2 numbered 2 in FIG. 25 represents a degree of coupling between the third port port3 and a seventh port port7, namely, isolation between the two ports, where a smaller value of S1,2 indicates a lower degree of coupling between the two ports, higher isolation, and better antenna performance.

[0176] It can be learned from coordinates of a point 7 on the curve 2 that, a fourth matching circuit 131 performs filtering at 1.4 GHz, a fifth matching circuit 132 performs filtering at 2.2 GHz, isolation at 1.4 GHz and 2.2 GHz is the highest, minimum isolation in a frequency band between two frequencies is 12.743 dB, isolation between the two ports is high, and the performance of the antenna structure is good.

[0177] A curve S2,2 FS 1 instance 3 numbered 3 in FIG. 25 represents a correspondence between a return loss of the seventh port port7 in free space and the frequency.

[0178] A curve System Tot. Efficiency [AC1]FS 1 example 3 numbered 4 in FIG. 25 represents a correspondence between antenna efficiency of a first antenna stub 11 in free space and the frequency.

[0179] A curve System Tot. Efficiency [AC1]FS port2 example 3 numbered 5 in FIG. 25 represents a correspondence between antenna efficiency of a third antenna stub 13 in free space and the frequency.

[0180] In this case, the third antenna stub may operate at a low band (Low Band, LB). In a typical frequency band division manner, LB ranges from 0.698 GHz to 0.960 GHz.

[0181] FIG. 26 is a simulation diagram 4 of antenna efficiency according to an embodiment of this application.

[0182] FIG. 26 mainly shows a simulation result of antenna efficiency in an MHB frequency band.

[0183] A curve System Tot. Efficiency [AC1]FS 1 example 3 numbered 1 in FIG. 26 represents a correspondence between efficiency of the antenna structure in FIG. 24 in free space and a frequency.

[0184] A curve System Tot. Efficiency [AC1] HR 1 example 3 numbered 2 in FIG. 26 represents a correspondence between efficiency of the antenna structure in FIG. 24 with right-hand phantom and the frequency.

[0185] A curve System Tot. Efficiency [AC1]_1 HL example 3 numbered 3 in FIG. 26 represents a correspondence between efficiency of the antenna structure in FIG. 24 with left-hand phantom and the frequency.

[0186] A curve System Tot. Efficiency [AC1]_chagngui FS numbered 4 in FIG. 26 represents a correspondence between efficiency of a conventional antenna structure in free space and the frequency. The conventional antenna structure is an antenna structure that does not include a second antenna stub or a third antenna stub.

[0187] A curve System Tot. Efficiency [AC1] chagngui HL numbered 5 in FIG. 26 represents a correspondence between efficiency of the conventional antenna structure with left-hand phantom and the frequency.

[0188] A curve System Tot. Efficiency [AC1] chagngui HR numbered 6 in FIG. 26 represents a correspondence between efficiency of the conventional antenna structure with right-hand phantom and the frequency.

[0189] It may be found from a point 1 on the curve 1 and a point 2 on the curve 2 that, after the technical solutions of this application are used, a right-hand phantom efficiency reduction in the MHB frequency band is approximately 2.7 dB, and a left-hand phantom efficiency reduction in the MHB frequency band is also approximately 2.7 dB. It may be found from a point 3 on the curve 4 and a point 4 on the curve 5 that, a left-hand phantom efficiency reduction of a conventional antenna is approximately 4.2073 dB. It may be found from the point 3 on the curve 4 and a point 5 on the curve 6 that, a right-hand phantom efficiency reduction of the conventional antenna is approximately 6.3499 dB. Therefore, according to the solutions provided in this embodiment of this application, the left-hand phantom efficiency reduction and the right-hand phantom efficiency reduction both are effectively improved, and performance of the antenna structure is improved.

[0190] In addition, in the MHB frequency band, the curve 2 is substantially higher than the curve 6 and the curve 3 is substantially higher than the curve 5 in FIG. 26. It indicates that the antenna structure of this embodiment not only can reduce the hand phantom efficiency reduction, but also improves hand phantom efficiency of the antenna structure in the MHB frequency band.

[0191] In conclusion, according to the antenna structure provided in this embodiment of this application, the second antenna stub is added to the conventional antenna structure, and two ports of the second antenna stub are grounded through inductors, so that an electric field on a body of a first antenna stub can be reduced. In addition, a normal electric field is constructed at the second antenna stub. Because the normal electric field penetrates the human body, an electric field penetrating the human body is reduced. Therefore, the hand phantom efficiency reduction of the antenna structure is reduced. In addition, the third antenna stub is further disposed, so that a reference ground of the antenna structure is lowered, and a normal electric field component is further increased. Therefore, the hand phantom efficiency reduction of the antenna structure is further reduced. Further, the third antenna stub is connected to a separate feed, so that the third antenna stub is excited to act as a separate antenna. In addition, isolation between the third antenna stub and the first antenna stub is ensured by using a filter circuit, so that a frequency band supported by the antenna structure is expanded, and an integration level and practicability of the antenna structure are further improved.

[0192] In the foregoing embodiment, an example in which the third antenna stub is connected to a feed is used for description. In some other embodiments, the second antenna stub may also be connected to a feed, and is excited to act as an antenna. Detailed descriptions are provided below with reference to the accompanying drawings.

[0193] FIG. 27 is a schematic diagram of yet another antenna structure according to an embodiment of this application.

[0194] A difference between the antenna structure shown in FIG. 27 and the antenna structure shown in FIG. 23 is that a first port port1 of a second antenna stub 12 is further configured to be connected to a third feed feed3, to excite the second antenna stub 12 to act as an antenna.

[0195] In actual application, when the second antenna stub 12 acts as an antenna, an operating frequency band of the second antenna stub 12 does not overlap an operating frequency band of a first antenna stub 11 and an operating frequency band of a third antenna stub 13. In this case, it is equivalent to integrating three antennas into the antenna structure provided in this embodiment of this application, so that an integration level of the antenna structure is improved.

[0196] In this case, filtering is implemented between the second antenna stub 12 and the first antenna stub 11 through a first matching circuit, to improve isolation between the two antennas.

[0197] For descriptions about a principle and technical effects of exciting the third antenna stub 13 to act as an antenna, refer to the foregoing embodiment. Details are not described herein again.

[0198] Technical effects of this embodiment are described below with reference to a simulation test.

[0199] FIG. 28 is an equivalent circuit diagram 3 of an antenna structure according to an embodiment of this application.

[0200] A first filter circuit included in a fourth matching circuit 131 is specifically a first filter capacitor and a first filter inductor that are connected in series, where a capacitance value of the first filter capacitor is 0.6 pF, and an inductance value of the first filter inductor is 20 nH.

[0201] A second filter circuit included in a fifth matching circuit 132 is specifically a second filter capacitor and a second filter inductor that are connected in series, where a capacitance value of the first filter capacitor is 0.5 pF, and an inductance value of the first filter inductor is 10 nH.

[0202] An inductor of a first matching circuit 121 and an inductor of a second matching circuit 122 both are 3 nH. An inductor of a third matching circuit 111 is 10 nH. When a third port port3 is connected to a first feed feed1, the third port port3 is connected in parallel to a 5.1 nH inductor. When a seventh port port7 is connected to a second feed feed2, the seventh port port7 is connected in parallel to a 0.5 pF capacitor. When a first port port1 is connected to a third feed feed3, the first port port1 is further connected in parallel to a 0.6 pF capacitor.

[0203] The antenna structure shown in FIG. 28 is simulated, and a simulation result is as follows.

[0204] FIG. 29 is a simulation diagram 6 of a resonance frequency of an antenna structure according to an embodiment of this application.

[0205] FIG. 29 includes the curves 1 to 5 shown in FIG. 25, and specific meanings of the curves 1 to 5 are the same as those in FIG. 25. Details are not described herein again.

[0206] A curve 7 in FIG. 29 represents a correspondence between a return loss of a first port port1 in free space and a frequency.

[0207] A curve 8 in FIG. 29 represents a correspondence between antenna efficiency of a second antenna stub 12 in free space and the frequency.

[0208] A curve 9 in FIG. 29 represents a degree of coupling between the first port port1 and a third port port3, namely, isolation between the two ports, where a smaller value indicates a lower degree of coupling between the two ports, higher isolation, and better antenna performance.

[0209] It can be learned from coordinates of a point 4 on the curve 9 that, minimum isolation in a frequency band is 9.7485 dB, isolation between the two ports is high, and performance of the antenna structure is good.

[0210] A first matching circuit 121 mainly implements filtering at approximately 2.1356 GHz.

[0211] FIG. 30 is a simulation diagram 5 of antenna efficiency according to an embodiment of this application.

[0212] FIG. 30 mainly shows a simulation result of antenna efficiency in an MHB frequency band.

[0213] A curve System Tot. Efficiency [AC1] FS port1 example 4 numbered 1 in FIG. 30 represents a correspondence between efficiency of the antenna structure in FIG. 28 in free space and a frequency.

[0214] A curve System Tot. Efficiency [AC1] HR port1 example 4 numbered 2 in FIG. 30 represents a correspondence between efficiency of the antenna structure in FIG. 28 with right-hand phantom and the frequency.

[0215] A curve System Tot. Efficiency [AC1]_1 HL port1 example 4 numbered 3 in FIG. 30 represents a correspondence between efficiency of the antenna structure in FIG. 28 with left-hand phantom and the frequency.

[0216] A curve System Tot. Efficiency [AC1]_chagngui FS numbered 4 in FIG. 30 represents a correspondence between efficiency of a conventional antenna structure in free space and the frequency. The conventional antenna structure is an antenna structure that does not include a second antenna stub or a third antenna stub.

[0217] A curve System Tot. Efficiency [AC1] chagngui HL numbered 5 in FIG. 30 represents a correspondence between efficiency of the conventional antenna structure with left-hand phantom and the frequency.

[0218] A curve System Tot. Efficiency [AC1] chagngui HR numbered 6 in FIG. 30 represents a correspondence between efficiency of the conventional antenna structure with right-hand phantom and the frequency.

[0219] It may be found from a point 1 on the curve 1 and a point 2 on the curve 2 that, after the technical solutions of this application are used, a right-hand phantom efficiency reduction in an MHB frequency band is approximately 2.4114 dB.

[0220] It may be found from the point 1 on the curve 1 and a point 3 on the curve 3 that, after the technical solutions of this application are used, a left-hand phantom efficiency reduction in the MHB frequency band is approximately 2.0598 dB.

[0221] It may be found from a point 4 on the curve 4 and a point 5 on the curve 5 that, a left-hand phantom efficiency reduction of a conventional antenna is approximately 4.2128 dB.

[0222] It may be found from the point 4 on the curve 4 and a point 6 on the curve 6 that, a right-hand phantom efficiency reduction of the conventional antenna is approximately 6.3609 dB.

[0223] Therefore, after the solutions provided in this embodiment of this application are used, the left-hand phantom efficiency reduction is reduced by approximately 4.2128 dB-2.0598 dB=2.153 dB.

[0224] In addition, the left-hand phantom efficiency reduction is reduced by approximately 6.3609 dB-2.4114 dB=3.9495 dB.

[0225] In addition, in the MHB frequency band, the curve 2 is substantially higher than the curve 6 and the curve 3 is substantially higher than the curve 5 in FIG. 26. It indicates that the antenna structure of this embodiment not only can reduce the hand phantom efficiency reduction, but also improves hand phantom efficiency of the antenna structure in the MHB frequency band. Left-hand phantom efficiency is improved by approximately 1 dB, and right-hand phantom efficiency is improved by approximately 2.7 dB.

[0226] In conclusion, according to the antenna structure provided in this embodiment of this application, the second antenna stub is added to the conventional antenna structure, and two ports of the second antenna stub are grounded through inductors, so that an electric field on a body of a first antenna stub can be reduced. In addition, a normal electric field is constructed at the second antenna stub. Because the normal electric field penetrates the human body less, an electric field penetrating the human body is reduced. Therefore, the hand phantom efficiency reduction of the antenna structure is reduced. In addition, the third antenna stub is further disposed, so that a reference ground of the antenna structure is lowered, and a normal electric field component is further increased. Therefore, the hand phantom efficiency reduction of the antenna structure is further reduced. Further, the third antenna stub is connected to a separate feed, so that the third antenna stub is excited to act as a separate antenna. In addition, isolation between the third antenna stub and the first antenna stub is ensured by using a filter circuit, so that a frequency band supported by the antenna structure is expanded, and an integration level and practicability of the antenna structure are further improved. In addition, the second antenna stub is connected to a separate feed, so that the second antenna stub is excited to act as a separate antenna. In addition, isolation between the second antenna stub and the first antenna stub is ensured by using a first matching circuit, so that a frequency band supported by the antenna structure is expanded, and the integration level and the practicability of the antenna structure are further improved.

[0227] In addition, in some other embodiments, the antenna structure may further use an implementation shown in FIG. 31. In this implementation, the third antenna stub 13 is not connected to a feed, in other words, is not excited to act as an antenna. The second antenna stub 12 is connected to a feed, and is excited to act as an antenna. A principle is similar to that described in the foregoing embodiment. Details are not described herein again.

[0228] In this embodiment of this application, an inductor used in each matching circuit may be a distributed inductor, an inductor spring, a lumped inductor, or a combination of the foregoing types. This is not specifically limited in this embodiment of this application.

[0229] In the foregoing descriptions of this application, an example in which an operating frequency of the first antenna stub 11 of the antenna structure is the MHB is used. In actual application, the operating frequency band of the first antenna stub 11 may be another higher frequency band, for example, may be an n77 frequency band, an n78 frequency band, or an n79 frequency band.

[0230] Based on the antenna structure provided in the foregoing embodiments, an embodiment of this application further provides an electronic device. Detailed descriptions are provided below with reference to the accompanying drawings.

[0231] FIG. 32 is a schematic diagram of an electronic device according to an embodiment of this application.

[0232] The electronic device 100 may be a non-foldable screen mobile phone, a foldable screen mobile phone, a wearable electronic device (for example, a smart watch), a tablet computer, or the like. The electronic device 100 includes a processor 110, a first antenna group 120, a second antenna group 130, a mobile communication module 140, and a wireless communication module 150.

[0233] It may be understood that the structure illustrated in this embodiment of the present invention does not constitute a specific limitation on the electronic device 100. In some other embodiments of this application, the electronic device 100 may include more or fewer components than those shown in the figure, some components may be combined, some components may be split, or different component arrangements may be used. The components shown in the figure may be implemented by using hardware, software, or a combination of software and hardware.

[0234] The processor 110 may include one or more processing units. For example, the processor 110 may include an application processor (application processor, AP), a modem processor, a graphics processing unit (graphics processing unit, GPU), an image signal processor (image signal processor, ISP), a controller, a video codec, a digital signal processor (digital signal processor, DSP), a baseband processor, and / or a neural-network processing unit (neural-network processing unit, NPU). Different processing units may be separate devices, or may be integrated into one or more processors. The controller may generate an operation control signal based on instruction operation code and a time-sequence signal, and control obtaining and executing of instructions. A memory may be further disposed in the processor 110, to store instructions and data.

[0235] A wireless communication function of the electronic device 100 may be implemented by using the first antenna group 120, the second antenna group 130, the mobile communication module 140, the wireless communication module 150, the modem processor, the baseband processor, and the like.

[0236] The first antenna group 120 and the second antenna group 130 are configured to transmit and receive an electromagnetic wave signal. Each antenna in the electronic device 100 may be configured to cover one or more communication frequency bands. Different antennas may further be multiplexed to improve antenna utilization. For example, an antenna in the first antenna group 120 may be multiplexed as a diversity antenna of a wireless local area network. In some other embodiments, the antenna may be used in combination with a tuning switch.

[0237] The mobile communication module 140 may provide wireless communication solutions that include 2G, 3G, 4G, 5G, or the like and that are applied to the electronic device 100. The mobile communication module 140 may include at least one filter, a switch, a power amplifier, a low noise amplifier (low noise amplifier, LNA), and the like. The mobile communication module 140 may receive an electromagnetic wave via the first antenna group 120, perform processing such as filtering, amplification, and the like on the received electromagnetic wave, and transmit the received electromagnetic wave to the modem processor for demodulation. The mobile communication module 140 may further amplify a signal modulated by the modem processor, and convert the signal into an electromagnetic wave via the first antenna group 120 for radiation. In some embodiments, at least some functional modules of the mobile communication module 140 may be disposed in the processor 110. In some embodiments, at least some functional modules of the mobile communication module 140 and at least some modules of the processor 110 may be disposed in a same device.

[0238] The modem processor may include a modulator and a demodulator. The modulator is configured to modulate a to-be-sent low-frequency baseband signal into a medium-highfrequency signal. The demodulator is configured to demodulate the received electromagnetic wave signal into a low-frequency baseband signal. Then, the demodulator transmits, to the baseband processor for processing, the low-frequency baseband signal obtained through demodulation. The low-frequency baseband signal is processed by the baseband processor and then transmitted to the application processor. In some other embodiments, the modem processor may be independent of the processor 110, and the modem processor and the mobile communication module 140 or another functional module may be disposed in a same device.

[0239] The wireless communication module 150 may provide wireless communication solutions that are applied to the electronic device 100 and that include wireless local area networks (wireless local area networks, WLAN) (for example, a Wi-Fi network), Bluetooth (bluetooth, BT), a global navigation satellite system (global navigation satellite system, GNSS), frequency modulation (frequency modulation, FM), a near field communication (near field communication, NFC) technology, an infrared (infrared, IR) technology, and the like. The wireless communications module 150 may be one or more devices integrating at least one communication processing module. The wireless communication module 150 receives an electromagnetic wave via the second antenna group 130, performs frequency modulation and filtering on an electromagnetic wave signal, and sends a processed signal to the processor 110. The wireless communication module 150 may further receive a to-be-sent signal from the processor 110, perform frequency modulation and amplification on the signal, and convert, via the second antenna group 130, the signal into an electromagnetic wave for radiation.

[0240] In some embodiments, in the electronic device 100, the first antenna group 120 is coupled to the mobile communication module 140, and the second antenna group 130 is coupled to the wireless communication module 150, so that the electronic device 100 can communicate with a network and another device by using a wireless communication technology. The wireless communication technology may include a global system for mobile communication (global system for mobile communications, GSM), a general packet radio service (general packet radio service, GPRS), code division multiple access (code division multiple access, CDMA), wideband code division multiple access (wideband code division multiple access, WCDMA), time-division code division multiple access (time-division code division multiple access, TD-SCDMA), long term evolution (long term evolution, LTE), BT, a GNSS, a WLAN, NFC, FM, an IR technology, and / or the like. The GNSS may include a global positioning system (global positioning system, GPS), a global navigation satellite system (global navigation satellite system, GLONASS), a beidou navigation satellite system (beidou navigation satellite system, BDS), a quasi-zenith satellite system (quasi-zenith satellite system, QZSS), and / or satellite based augmentation systems (satellite based augmentation systems, SBAS).

[0241] The electronic device 100 may include one or more antenna structures provided in the foregoing embodiments, to implement a mobile communication function. In other words, the antenna structure may be used as an antenna in the first antenna group 120. For a specific implementation of the antenna structure, refer to descriptions in the foregoing embodiments. Details are not described herein again.

[0242] In actual application, an operating frequency band of a first antenna stub of the antenna structure is an MHB, for example, may cover a B1 frequency band and a B3 frequency band. The antenna structure may be disposed at a border frame position of the electronic device 100. Because hand phantom efficiency of the antenna structure is high, a communication capability of the electronic device can be improved. Detailed descriptions are provided below by using an example in which the electronic device is a mobile phone device.

[0243] FIG. 33 is a schematic diagram of another electronic device according to an embodiment of this application.

[0244] An example in which an antenna structure includes a first antenna stub 11, a second antenna stub 12, and a third antenna stub 13 is used. Border frames of the electronic device 100 are sequentially a first short border frame 101, a first long border frame 102, a second short border frame 103, and a second long border frame 104.

[0245] The electronic device in the figure includes one antenna structure, and the antenna structure is disposed at the second long border frame 104. In actual application, the antenna structure may alternatively be disposed at the first long border frame 102 of the electronic device.

[0246] In some other embodiments, the electronic device may include a plurality of antenna structures, and in this case, the plurality of antenna structures may all be disposed at the first long border frame 102. Alternatively, the plurality of antenna structures may all be disposed at the second long border frame 104. Alternatively, a first part of the plurality of antenna structures are disposed at the first long border frame 102, and a remaining second part of the plurality of antenna structures are disposed at the second long border frame 104.

[0247] FIG. 33 is still used as an example. When a user holds the electronic device with the left hand, the antenna structure is with left-hand phantom. When the user holds the electronic device with the right hand, the antenna structure is with right-hand phantom. It can be learned from the simulation diagrams with hand phantom in the foregoing embodiments, in comparison with a conventional antenna solution, after the solutions in this embodiment of this application are used, a left-hand phantom efficiency reduction is reduced, and a right-hand phantom efficiency reduction is also reduced. In addition, left-hand phantom efficiency and right-hand phantom efficiency both are improved, so that communication quality of the electronic device with hand phantom is ensured, and user experience is improved.

[0248] It should be understood that, in this application, "at least one" means one or more, and "a plurality of" means two or more. The term "and / or" is used for describing an association relationship between associated objects and representing that three relationships may exist. For example, "A and / or B" may represent the following three cases: Only A exists, only B exists, and both A and B exist, where A and B may be singular or plural.

[0249] The foregoing embodiments are merely used to describe the technical solutions of this application, but are not intended to limit the technical solutions. Although this application is described in detail with reference to the foregoing embodiments, a person of ordinary skill in the art should understand that modifications may still be made to the technical solutions described in the foregoing embodiments, or equivalent replacements may be made to the part of the technical features. However, these modifications or replacements do not cause the essence of corresponding technical solutions to depart from the spirit and scope of the technical solutions in embodiments of this application.

Claims

1. An antenna structure, wherein the antenna structure comprises: a first antenna stub, a second antenna stub, a first matching circuit, and a second matching circuit, wherein the first antenna stub is connected to the second antenna stub; the second antenna stub comprises a first port and a second port, the first port is grounded through the first matching circuit, the second port is grounded through the second matching circuit, the first matching circuit comprises a first inductor, and the second matching circuit comprises a second inductor; and the first antenna stub comprises a third port, and the third port is configured to be connected to a first feed.

2. The antenna structure according to claim 1, wherein the antenna structure comprises a third matching circuit; the first antenna stub further comprises a fourth port; and the fourth port is grounded through the third matching circuit, and the third matching circuit comprises a third inductor.

3. The antenna structure according to claim 1, wherein the antenna structure comprises a third antenna stub; a first end of the third antenna stub is grounded, and a first gap exists between a second end of the third antenna stub and a first end of the first antenna stub; and a second end of the first antenna stub is connected to a first end of the second antenna stub.

4. The antenna structure according to claim 3, wherein a sum of a length of the third antenna stub and a length of the first antenna stub is a half of an operating wavelength of the first antenna stub.

5. The antenna structure according to claim 3, wherein the antenna structure further comprises a third matching circuit; the first antenna stub further comprises a fourth port; and the fourth port is grounded through the third matching circuit, and the third matching circuit comprises a third inductor.

6. The antenna structure according to claim 5, wherein a length of the first antenna stub is less than a quarter of an operating wavelength of the first antenna stub.

7. The antenna structure according to claim 3, wherein the antenna structure further comprises a fourth matching circuit; the third antenna stub further comprises a fifth port; and the fifth port is grounded through the fourth matching circuit.

8. The antenna structure according to claim 7, wherein a distance between the fifth port and the first gap is a quarter of an operating wavelength of the first antenna stub; and the fourth matching circuit is a zero-ohm resistance.

9. The antenna structure according to claim 7, wherein the antenna structure further comprises a fifth matching circuit; the third antenna stub further comprises a sixth port; the sixth port is located between the fifth port and the first gap; and the sixth port is grounded through the fifth matching circuit.

10. The antenna structure according to claim 9, wherein the third antenna stub further comprises a seventh port, and the seventh port is configured to be connected to a second feed.

11. The antenna structure according to claim 10, wherein the fourth matching circuit comprises a first filter circuit, and the fifth matching circuit comprises a second filter circuit; a filtering frequency of the first filter circuit is a first operating frequency of the first antenna stub; and a filtering frequency of the second filter circuit is a second operating frequency of the first antenna stub.

12. The antenna structure according to claim 11, wherein the first filter circuit comprises a first filter capacitor and a first filter inductor that are connected in series; and the second filter circuit comprises a second filter capacitor and a second filter inductor that are connected in series.

13. The antenna structure according to claim 3, wherein the first antenna stub, the second antenna stub, and the third antenna stub are specifically any one of the following: metal conductors, steel sheets, flexible printed circuit antenna PFC antenna stubs, printing direct structure PDS antenna stubs, or laser-direct-structuring LDS antenna stubs.

14. The antenna structure according to any one of claims 1 to 13, wherein the first port is further connected to a third feed.

15. The antenna structure according to claim 1, wherein the first inductor and the second inductor may be separately a combination of one or more of the following: a distributed inductor, an inductor spring, or a lumped inductor.

16. The antenna structure according to claim 1, wherein the first antenna stub operates in a middle high band MHB.

17. An electronic device, wherein the electronic device comprises one or more antenna structures according to any one of claims 1 to 16.

18. The electronic device according to claim 17, wherein the electronic device comprises one antenna structure; and border frames of the electronic device are sequentially a first short border frame, a first long border frame, a second short border frame, and a second long border frame, and the antenna structure is disposed at the first long border frame or the second long border frame.

19. The electronic device according to claim 17, wherein the electronic device comprises a plurality of antenna structures; border frames of the electronic device are sequentially a first short border frame, a first long border frame, a second short border frame, and a second long border frame; and the plurality of antenna structures are all disposed at the first long border frame; or the plurality of antenna structures are all disposed at the second long border frame; or a first part of the plurality of antenna structures are disposed at the first long border frame, and a second part of the plurality of antenna structures are disposed at the second long border frame.

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