Antenna module and electronic device

Abstract

The application discloses an antenna module and an electronic device, and belongs to the technical field of antennas. The antenna module comprises: an inverted F antenna, the inverted F antenna comprising a radiation branch extending along a first direction; and a metal piece, the metal piece being used for enhancing an electric field component of the inverted F antenna in a second direction, the second direction being perpendicular to the first direction.

Description

Technical Field

[0001] This application belongs to the field of antenna technology, specifically relating to an antenna module and electronic equipment. Background Technology

[0002] When users use mobile phones and other electronic devices, the electromagnetic waves radiated by the antenna are absorbed by the human body. This absorbed energy is usually quantified by the Specific Absorption Ratio (SAR). The lower the SAR value, the less electromagnetic energy is absorbed by the human body, and the less impact it has on human health. Since the SAR value is directly proportional to the antenna's total radiated power (TRP), related technologies generally reduce the SAR value by lowering the antenna's total radiated power. However, the lower the antenna's total radiated power, the worse the communication capability of the electronic device. Therefore, to ensure the communication capability of the electronic device, the antenna's total radiated power needs to meet a certain level, making it difficult to reduce the SAR value to a lower level.

[0003] It is evident that the SAR reduction schemes in related technologies suffer from poor SAR reduction performance. Summary of the Invention

[0004] The purpose of this application is to provide an antenna module and electronic device that can solve the problem of poor SAR reduction effect in related technologies.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows:

[0006] In a first aspect, embodiments of this application propose an antenna module, comprising:

[0007] An inverted-F antenna, the inverted-F antenna including radiating branches extending along a first direction;

[0008] A metal component is provided to enhance the electric field component of the inverted-F antenna in a second direction, which is perpendicular to the first direction.

[0009] Secondly, embodiments of this application provide an electronic device including an antenna module as described in the first aspect.

[0010] In the embodiments of this application, by setting a metal component to enhance the electric field component of the inverted-F antenna in the second direction, that is, to enhance the normal component of the near-field electric field of the inverted-F antenna, and to reduce the electric field component of the inverted-F antenna in the first direction, that is, to reduce the tangential component of the near-field electric field of the inverted-F antenna, the inverted-F antenna can significantly reduce the electric field intensity obtained in human tissue while maintaining the total radiated power requirement, thereby realizing the SAR reduction design of the antenna and improving the SAR reduction effect of the antenna.

[0011] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0012] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0013] Figure 1 This is one of the structural schematic diagrams of the antenna module provided in the embodiments of this application;

[0014] Figure 2 yes Figure 1 The diagram shows the structure of the inverted F antenna.

[0015] Figure 3 This is the second schematic diagram of the antenna module provided in the embodiments of this application;

[0016] Figure 4 yes Figure 3 The diagram shows the structure of the inverted F antenna.

[0017] Figure 5 yes Figure 3 A schematic diagram of the structure of the metal component shown;

[0018] Figure 6 This is a schematic diagram of antenna SAR simulation provided in the embodiments of this application;

[0019] Figure 7 This is a schematic diagram of electromagnetic waves entering the human body, provided in an embodiment of this application. Detailed Implementation

[0020] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. 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. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0021] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0022] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and 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.

[0023] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" 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 or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0024] like Figures 1 to 7 As shown, this application embodiment provides an antenna module, including:

[0025] An inverted-F antenna 10, which includes radiating branches 11 extending along a first direction;

[0026] Metal component 20 is used to enhance the electric field component of the inverted-F antenna in a second direction, which is perpendicular to the first direction.

[0027] The metal part 20 can be directly connected to the grounding point on the radiating branch 11, or it can be connected to the grounding structure corresponding to the grounding point on the radiating branch 11, so that the metal part 20 can enhance the electric field component of the inverted F antenna in the second direction, thereby enabling the inverted F antenna to reduce the electric field component of the inverted F antenna in the first direction while maintaining the total radiated power requirement.

[0028] In the case where the metal part 20 is electrically connected to the grounding structure corresponding to the grounding point on the radiating branch 11, the metal part 20 can be placed close to the radiating branch 11 so that the placement of the metal part 20 can enhance the electric field component of the inverted F antenna in the second direction.

[0029] The SAR value represents the amount of electromagnetic energy absorbed by human tissue in an electromagnetic field, and the expression for the local SAR value calculated based on the electric field is as follows:

[0030]

[0031] In the formula, ρ represents the density of human tissue, and σ represents the conductivity of human tissue. This represents the effective value of the electric field inside the human body.

[0032] As can be seen from the above expression for SAR value, when the density and conductivity of human tissue are determined, the magnitude of the electromagnetic field energy absorbed by human tissue, i.e., the SAR value, will depend entirely on the electric field strength inside the human body.

[0033] When electromagnetic waves radiated by an antenna in the air enter human tissue, the tissue, possessing specific electromagnetic parameters such as dielectric constant and permeability, is essentially a dielectric, thus exhibiting reflection and refraction of the electromagnetic waves. For example... Figure 7 As shown, the electric field radiated by the antenna After entering the human body from the air, it becomes Furthermore, the amplitude and direction of propagation of the electric field change after entering the human body.

[0034] Among them, the boundary conditions related to the electric field in Maxwell's equations include the following expressions:

[0035]

[0036] In the formula, and This represents the normal component of the electric field at the interface between the human body and the air. and This represents the tangential component of the electric field at the interface between the human body and the air.

[0037] Due to the significant differences in electromagnetic properties between human tissue and air—for example, the dielectric constant of the human body (ε2) is more than 40 times higher than that of air (ε1), and the charge distribution (ρ) at the interface between the human body and air… s (rarely, that is to say) Therefore, a large difference in dielectric constant makes Compare The electric field is much larger, meaning that the normal component of the electric field perpendicular to the interface between the human body and the air will be significantly attenuated when it enters the human body.

[0038] On the other hand, due to That is, the tangential component of the electric field parallel to the interface between the human body and the air does not change before and after entering the human body. In other words, the tangential component of the antenna's near-field electric field is easy to enter the human body, while the normal component is difficult to enter the human body.

[0039] In this embodiment, by setting the metal part 20, the electric field component of the inverted F antenna 10 in the second direction is enhanced, that is, the normal component of the near-field electric field of the inverted F antenna 10 is enhanced, and the electric field component of the inverted F antenna 10 in the first direction is reduced, that is, the tangential component of the near-field electric field of the inverted F antenna 10 is reduced. This allows the inverted F antenna 10 to significantly reduce the electric field intensity obtained in human tissue while maintaining the total radiated power requirement, thereby realizing the SAR reduction design of the antenna and improving the SAR reduction effect of the antenna.

[0040] In some embodiments, the length of the radiating branch 11 is 1 / 4λ, and a first grounding point 111 and a feed point 112 are provided on the radiating branch 11. The radiating branch 11 is grounded through the first grounding point 111 and electrically connected to the feed structure 12 of the inverted F antenna 10 through the feed point 112. The first grounding point 111 is provided at the end of the radiating branch 11.

[0041] Wherein, λ is the dielectric wavelength corresponding to the operating frequency band of the inverted-F antenna 10.

[0042] When the inverted F antenna 10 is an antenna structure installed on an electronic device such as a mobile phone, the radiating branch 11 can be a metal arm installed on the side frame of the electronic device. The first grounding point 111 can be connected to the grounding structure of the electronic device through a grounding connector, such as being connected to the inner frame of the metal frame of the electronic device through a metal connecting rib, so as to achieve the grounding of the radiating branch 11.

[0043] In some embodiments, the feed structure 12 includes a feed source and a microstrip feed line. The feed source is used to output a feed signal, and the microstrip feed line is used to connect the feed point 112 of the radiating branch 11 and the feed source, so that the feed signal output by the feed source can be transmitted to the radiating branch 11.

[0044] In some embodiments, when the inverted-F antenna 10 is an antenna structure disposed on an electronic device such as a mobile phone, the feed source may be disposed on a circuit board such as the motherboard of the electronic device.

[0045] In some embodiments, the coverage frequency band of the inverted-F antenna 10 is 1710MHz to 2690MHz, and the length of the radiating branch 11 is 25mm. Furthermore, during the SAR value simulation, the current direction of the inverted-F antenna 10 is parallel to the human tissue, meaning the electric field component of the inverted-F antenna 10 along the first direction is a tangential component. The antenna efficiency and SAR value of the inverted-F antenna 10 at this time are shown in Table 1.

[0046] Table 1

[0047] Frequency (GHz) Efficiency (-dB) SAR value (W / kg) 1.77 -8.5 1.57

[0048] In some embodiments, λ is the dielectric wavelength corresponding to the frequency band around 1800MHz, and the distance between the first ground point 111 and the feed point 112 can be about 5 mm, so that the portion between the feed point 112 of the radiating branch 11 and the end of the radiating branch 11 away from the first ground point 111 can generate a 1 / 4 mode in the frequency band around 2500MHz.

[0049] In some embodiments, such as Figure 1 and Figure 2 As shown, the metal part 20 is electrically connected to the grounding structure 30 corresponding to the first grounding point 111, and the metal part 20 does not extend into the clearance area of ​​the inverted F antenna 10.

[0050] In this embodiment, by electrically connecting the metal part 20 to the grounding structure 30 corresponding to the first grounding point 111, the setting of the metal part 20 can increase the electric field component of the inverted F antenna 10 in the second direction, that is, increase the normal component of the near-field electric field of the inverted F antenna 10, thereby realizing the antenna's SAR reduction design and improving the antenna's SAR reduction effect.

[0051] The metal part 20 is electrically connected to the grounding structure 30 corresponding to the first grounding point 111, which can be understood as the metal part 20 and the first grounding point 111 on the radial branch 11 sharing a grounding structure.

[0052] When the inverted-F antenna 10 is used in electronic devices such as mobile phones, the grounding structure 30 can be understood as the metal frame of the electronic device. Specifically, the radiating branches 11 of the inverted-F antenna 10 can be set on the outer frame of the metal frame, and the grounding structure 30 can be understood as the inner frame of the metal frame.

[0053] When the metal part 20 is electrically connected to the grounding structure 30 corresponding to the first grounding point 111, the simulation results of the SAR value are shown in Table 2.

[0054] Table 2

[0055] Frequency (GHz) Efficiency (-dB) SAR value (W / kg) 1.77 -8.6 1.15

[0056] By comparing the simulation results of the SAR values ​​shown in Tables 1 and 2, it can be seen that by setting the metal part 20, the electric field component of the inverted F antenna 10 in the second direction can be enhanced, that is, the normal component of the near-field electric field of the inverted F antenna 10 can be increased, thereby significantly reducing the SAR value while maintaining the total radiated power requirement of the inverted F antenna 10.

[0057] In some embodiments, the metal part 20 can be a metal block structure, and the length of the metal part 20 in the second direction is 1 / 8λ to 1 / 4λ, which can enhance the electric field component of the inverted F antenna 10 in the second direction.

[0058] In some embodiments, the length of the metal part 20 in the first direction can be set to 1 / 8λ, which can further enhance the electric field component of the inverted-F antenna 10 in the second direction.

[0059] The length of the metal part 20 in the first direction can also be set to about 10 mm, and 10 mm is close to 1 / 8λ of the intermediate frequency 1800MHz in the mobile phone medium.

[0060] It is understandable that, in the case that the inverted F antenna 10 is an antenna structure installed on electronic devices such as mobile phones, the metal part 20 can be a metal block structure installed on the plastic back cover of the electronic device.

[0061] In some embodiments, such as Figures 3 to 5 As shown, a second grounding point 113 is provided on the radiating branch 11. The distance between the second grounding point 113 and the first grounding point 111 is greater than or equal to 1 / 8λ, and the feed point 112 is located between the first grounding point 111 and the second grounding point 113.

[0062] The second grounding point 113 is grounded through the metal part 20.

[0063] In this embodiment, by setting a second grounding point 113 in the radiating branch 11 and using the metal part 20 to ground the second grounding point 113, that is, designing the second grounding point 113 to be grounded through the metal part 20, the electric field component of the inverted F antenna 10 in the second direction can be enhanced, that is, the normal component of the near-field electric field of the inverted F antenna 10 is increased, thereby realizing the SAR reduction design of the antenna and improving the SAR reduction effect of the antenna.

[0064] With the second grounding point 113 set in the radiating branch 11 and the second grounding point 113 grounded using the metal part 20, the data simulation results of the SAR value are shown in Table 3.

[0065] Table 3

[0066] Frequency (GHz) Efficiency (-dB) SAR value (W / kg) 1.77 -8.9 0.92

[0067] By comparing the simulation results of the SAR values ​​shown in Tables 1 and 3, it can be seen that by setting the metal part 20 and using the metal part 20 to achieve the grounding of the second grounding point 113, the electric field component of the inverted F antenna 10 in the second direction can be enhanced, that is, the normal component of the near-field electric field of the inverted F antenna 10 can be increased, thereby significantly reducing the SAR value while maintaining the total radiated power requirement of the inverted F antenna 10.

[0068] Furthermore, by comparing the simulation results of the SAR values ​​shown in Tables 2 and 3, it can be seen that although the radiation efficiency of the inverted-F antenna 10 is reduced by 0.3 dB, the SAR gain is 2 dB (after removing the efficiency loss, the pure SAR gain can still reach 1.7 dB). It is evident that by adding the metal component 20, changing the electric field component distribution of the inverted-F antenna 10, there is a significant benefit in reducing the antenna's SAR. Moreover, the bandwidth of the inverted-F antenna 10 can cover 1.71 GHz to 2.69 GHz and 3.3 GHz to 3.8 GHz.

[0069] In some embodiments, such as Figures 3 to 5 As shown, the metal part 20 is an L-shaped metal block structure. The metal part 20 includes a metal block body 21, a first connecting section 22 and a second connecting section 23. The first connecting section 22 is a connecting section formed by the metal block body 21 extending in a first direction, and the second connecting section 23 is a connecting section formed by the metal block body 21 extending in a second direction.

[0070] The end of the second connecting segment 23 that is away from the metal block body 21 is electrically connected to the second grounding point 113.

[0071] In this embodiment, by designing a metal part 20 including a metal block body 21, a first connecting section 22 and a second connecting section 23, and setting the end of the second connecting section 23 away from the metal block body 21 to be electrically connected to the second grounding point 113, the electric field component of the inverted F antenna 10 in the second direction can be enhanced, that is, the normal component of the near-field electric field of the inverted F antenna 10 can be increased, thereby realizing the SAR reduction design of the antenna and improving the SAR reduction effect of the antenna.

[0072] In some embodiments, a grounding connection portion 221 is provided on the first connecting segment 22, and the metal part 20 is grounded through the grounding connection portion 221. That is, the second grounding point 113, which is electrically connected to the second connecting segment 23, can be grounded through the grounding connection portion 221 on the first connecting segment 22 to meet the grounding requirements of the second grounding point 113 of the radiating branch 11.

[0073] Furthermore, the distance between the feed structure 12 and the ground connection portion 221 of the inverted F antenna 10 in the first direction is 1.5 to 2.5 mm, which reduces the interference of the design of the metal part 20 on the feed signal transmitted on the feed structure 12.

[0074] In some embodiments, the distance between the feed structure 12 of the inverted-F antenna 10 and the ground connection portion 221 in the first direction is 2 mm.

[0075] In some embodiments, the sum of the lengths of the first connecting segment 22 and the metal block body 21 in the first direction is 1 / 8λ to 1 / 4λ, which can enhance the electric field component of the inverted-F antenna 10 in the second direction.

[0076] In some embodiments, the sum of the lengths of the second connecting segment 23 and the metal block body 21 in the second direction is 1 / 8λ, which can further enhance the electric field component of the inverted-F antenna 10 in the second direction.

[0077] In some embodiments, the second connecting segment 23 and the feeding structure 12 of the inverted-F antenna 10 have a gap 40 in the first direction.

[0078] In this embodiment, by designing a gap 40 between the second connecting section 23 and the feed structure 12 of the inverted F antenna 10 in the first direction, the second connecting section 23 is prevented from covering the feed structure 12, and the interference of the design of the metal part 20 on the feed signal transmitted on the feed structure 12 can be reduced.

[0079] In some embodiments, the width of the gap 40 is set to be greater than or equal to 2 mm.

[0080] This application also provides an electronic device including the antenna module described above.

[0081] It should be noted that the implementation method of the antenna module embodiment described above is also applicable to the embodiment of the electronic device and can achieve the same technical effect, so it will not be described again here.

[0082] In some embodiments, the electronic device further includes a first frame and a plastic back cover, with the radiating branch 11 disposed on the first frame and the metal part 20 disposed on the plastic back cover;

[0083] The aforementioned first direction is the same as the extension direction of the first border.

[0084] The aforementioned first frame can be the side frame of the electronic device, that is, the radiating branch 11 of the inverted F antenna 10 can be set on the side frame of the electronic device.

[0085] The first frame can be a pure metal frame, or it can be a metal structure with only the part with the radiating branches 11 and the other parts are plastic.

[0086] In this embodiment, by placing the metal part 20 on the plastic back cover, not only can the placement of the metal part 20 reduce its impact on the net space of the antenna, but it will also not affect the overall layout of other components.

[0087] In some embodiments, the metal component 20 may be a metal layer structure, such as a copper layer, disposed on the plastic back cover; or it may be a flexible printed circuit (FPC) disposed on the plastic back cover.

[0088] Among them, electronic devices can be mobile phones, tablets, laptops, handheld computers, in-vehicle electronic devices, wearable devices, ultra-mobile personal computers (UMPCs), netbooks, or personal digital assistants (PDAs), etc.

[0089] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0090] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. An antenna module, characterized in that, include: An inverted-F antenna, the inverted-F antenna including radiating branches extending along a first direction; A metal component, the metal component being used to enhance the electric field component of the inverted-F antenna in a second direction, the second direction being perpendicular to the first direction; The radiating branch is provided with a first grounding point and a feed point. The radiating branch is grounded through the first grounding point and electrically connected to the feed structure of the inverted F antenna through the feed point. The first grounding point is located at the end of the radiating branch. The radiating branch is provided with a second grounding point, and the second grounding point is grounded through the metal component. The power supply point is located between the first grounding point and the second grounding point.

2. The antenna module according to claim 1, characterized in that, The length of the radiating branch is 1 / 4λ, where λ is the dielectric wavelength corresponding to the operating frequency band of the inverted-F antenna.

3. The antenna module according to claim 2, characterized in that, The metal component is electrically connected to the grounding structure corresponding to the first grounding point, and the metal component does not extend into the clearance area of ​​the inverted F antenna.

4. The antenna module according to claim 3, characterized in that, The metal component is a metal block structure, and the length of the metal component in the second direction is 1 / 8λ to 1 / 4λ.

5. The antenna module according to claim 4, characterized in that, The length of the metal part in the first direction is 1 / 8λ.

6. The antenna module according to claim 2, characterized in that, The distance between the second grounding point and the first grounding point is greater than or equal to 1 / 8λ.

7. The antenna module according to claim 6, characterized in that, The metal component is an L-shaped metal block structure, comprising a metal block body, a first connecting segment, and a second connecting segment. The first connecting segment is formed by the metal block body extending in a first direction, and the second connecting segment is formed by the metal block body extending in a second direction. The end of the second connecting segment furthest from the metal block body is electrically connected to the second grounding point.

8. The antenna module according to claim 7, characterized in that, The first connecting section is provided with a grounding connection part, and the metal part is grounded through the grounding connection part; The distance between the feed structure of the inverted-F antenna and the grounding connection in the first direction is 1.5~2.5 mm.

9. The antenna module according to claim 7, characterized in that, The sum of the lengths of the first connecting segment and the metal block body in the first direction is 1 / 8λ to 1 / 4λ.

10. The antenna module according to claim 9, characterized in that, The sum of the lengths of the second connecting segment and the metal block body in the second direction is 1 / 8λ.

11. The antenna module according to any one of claims 7 to 10, characterized in that, The second connecting segment and the feeding structure of the inverted F antenna have a gap in the first direction.

12. The antenna module according to claim 11, characterized in that, The width of the gap is greater than or equal to 2 millimeters.

13. An electronic device, characterized in that, Includes the antenna module as described in any one of claims 1 to 12.

14. The electronic device according to claim 13, characterized in that, The electronic device further includes a first frame and a plastic back cover, the radiating branches are disposed on the first frame, and the metal parts are disposed on the plastic back cover; Wherein, the first direction is the same as the extension direction of the first border.

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