Electronic device
By incorporating gaps and tuning structures in the IFA antenna, and optimizing the length and connection method of the antenna stubs, the problem of IFA antennas being unable to cover low and mid-to-high frequencies was solved, achieving good radiation efficiency and SAR performance, and supporting the lightweight design of electronic devices.
Patent Information
- Application Number
- CN202511070817.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-31
- Publication Date
- 2025-11-14
AI Technical Summary
Existing IFA antennas have difficulty covering both low and medium-high frequencies simultaneously, and also suffer from high SAR performance issues.
An antenna structure was designed, including a first radiating stub, a second radiating stub, a third radiating stub, and a connecting stub. By setting gaps and tuning structures, the mid-to-high frequency bands are blocked, forming a suspended stub to reduce the equivalent electrical size, achieving low-frequency and mid-to-high frequency coverage, and optimizing SAR performance.
It achieves good radiation performance and excellent SAR performance in low and mid-to-high frequency bands, reduces the space occupied by the antenna in electronic devices, and contributes to the development of thinner and lighter electronic devices.
Smart Images
Figure CN120955362A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of electronic equipment technology, and specifically relates to an electronic device. Background Technology
[0002] The amount of electromagnetic waves absorbed by the human body is mainly measured by the specific absorption ratio (SAR). The smaller the SAR value, the less impact electromagnetic radiation has on the human body. Because electromagnetic radiation can have adverse effects on the human body, people have begun to pay attention to its impact, and the new national standard for SAR imposes strict requirements on the SAR performance of electronic devices. In electronic devices, if the antenna is not specifically designed for SAR performance, it will be required to reduce its radio frequency conducted power, significantly reducing over-the-air (OTA) performance. On the other hand, with the increasing demand for electronic devices, the pursuit of thinner and lighter devices and extreme screen-to-body ratios has become an inevitable trend. However, this design significantly compresses the space for antenna arrangement, leading to a deterioration of the antenna environment. Currently, mid-to-high frequency inverted fantennas (IFA) are limited by the size of electronic devices and struggle to achieve low-frequency performance, while low-frequency IFA antennas struggle to achieve good radiation and SAR performance in the mid-to-high frequency bands. Therefore, existing IFA antennas are unable to cover low and mid-to-high frequencies and suffer from high SAR issues. Summary of the Invention
[0003] The purpose of this application is to provide an electronic device that can solve the problems of IFA antennas in related technologies having difficulty covering low and mid-high frequencies and having high SAR.
[0004] This application provides an electronic device including a base plate and an antenna structure. The antenna structure includes a first radiating stub, a second radiating stub, a third radiating stub, and a connecting stub. A first gap exists between the first and second radiating stubs, and a second gap exists between the second and third radiating stubs. The third radiating stub is connected to the connecting stub, and the extension direction of the third radiating stub is perpendicular to the extension direction of the connecting stub. The end of the connecting stub away from the third radiating stub is connected to the base plate. The base plate serves as the ground of the antenna structure. The total length of the first, second, and third radiating stubs is one-quarter of the operating wavelength of the low-frequency band, and the lengths of the first, second, and third radiating stubs are equal.
[0005] The first radiating branch and the second radiating branch are provided with a first tuning structure, and the second radiating branch and the third radiating branch are provided with a second tuning structure. The second tuning structure is used to block the mid-to-high frequency band.
[0006] In the electronic device provided in this application embodiment, a second gap exists between the second and third radiating stubs, and a second tuning structure is provided between the second and third radiating stubs. This second tuning structure is used to block the mid-to-high frequency band. Therefore, when the antenna structure operates in the mid-to-high frequency band, an open circuit is formed at the second gap, and the current is mainly distributed in the third radiating stub. Additionally, a first gap exists between the first and second radiating stubs, and a first tuning structure is provided between the first and second radiating stubs. This first tuning structure bridges the suspended first and second radiating stubs to form a complete suspended stub, which can reduce the equivalent electrical size of the suspended stub, making its half-wave resonant frequency far away from the mid-to-high frequency band. Therefore, the antenna structure provided in this application embodiment can cover both the low-frequency and mid-to-high frequency bands, and has good SAR performance in the mid-to-high frequency band. Attached Figure Description
[0007] Figure 1a This is one of the schematic diagrams of an antenna structure in related technologies;
[0008] Figures 1b-1d These are schematic diagrams of antenna structures operating in different modes in related technologies, numbered two to four.
[0009] Figure 1e This is a comparison of the radiation efficiency of an antenna structure in the three-quarters mid-frequency mode and the quarter-frequency mid-frequency mode in related technologies.
[0010] Figure 1f This is a comparison of SAR hotspot distribution in three-quarters and one-quarter mid-frequency modes of an antenna structure in related technologies.
[0011] Figure 2a This is one of the schematic diagrams of an antenna structure provided in the embodiments of this application;
[0012] Figure 2b yes Figure 2a One of the equivalent structure diagrams;
[0013] Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application;
[0014] Figure 4a This is a schematic diagram of the transmission coefficients of the second tuning structure in an antenna structure provided in an embodiment of this application;
[0015] Figure 4bThis is a comparison of the radiation efficiency of the improved antenna structure A provided in this application embodiment and a traditional low-frequency IFA antenna;
[0016] Figure 4c This is a comparison of the 5mmbody SAR hotspot distribution on the back of the improved antenna structure A provided in this application embodiment and a traditional low-frequency IFA antenna;
[0017] Figure 4d This is a comparison of the resonant mode current distribution at low and medium frequencies between the improved antenna structure A provided in this application embodiment and the traditional low-frequency IFA antenna;
[0018] Figure 5 This is a second schematic diagram of an antenna structure provided in an embodiment of this application;
[0019] Figures 6a-6b These are schematic diagrams three to four of an antenna structure provided in the embodiments of this application;
[0020] Figures 6c-6d yes Figure 6a or Figure 6b Equivalent structure diagram;
[0021] Figure 6e This is the fifth schematic diagram of an antenna structure provided in the embodiments of this application;
[0022] Figure 7a This is a comparison of the radiation efficiency of the improved antenna structure A and the improved antenna structure B provided in the embodiments of this application;
[0023] Figure 7b This is a comparison of the 5mmbody SAR hotspot distribution on the back of the improved antenna structure A and the improved antenna structure B provided in the embodiments of this application;
[0024] Figure 7c This is a comparison of the current distribution in the intermediate frequency mode of the improved antenna structure A and the improved antenna structure B provided in the embodiments of this application;
[0025] Figures 8a-8e These are schematic diagrams six through ten of an antenna structure provided in the embodiments of this application;
[0026] Figure 9a This is a schematic diagram of the radiation efficiency and system efficiency of the improved antenna structure C provided in the embodiments of this application;
[0027] Figure 9b This is a comparison of the 5mmbody SAR hotspot distribution on the back of the improved antenna structure C and the improved antenna structure B provided in the embodiments of this application;
[0028] Figure 9cThis is a comparison of the current distribution in the intermediate frequency mode of the improved antenna structure C and the improved antenna structure B provided in the embodiments of this application;
[0029] Figures 10a-10c This is a schematic diagram of the first tuning structure in an antenna structure provided in an embodiment of this application;
[0030] Figures 11a-11b This is a schematic diagram of the second tuning structure in an antenna structure provided in an embodiment of this application;
[0031] Figure 12 yes Figure 2a The second equivalent structure diagram;
[0032] Figures 13-15 These are schematic diagrams eleven to thirteen of an antenna structure provided in the embodiments of this application. Detailed Implementation
[0033] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0034] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.
[0035] Please refer to Figure 1a , Figure 1a The diagram shows a schematic of an antenna structure in related technologies. The antenna structure is an IFA antenna with a total length of l, where l should satisfy l≈0.25λ. Low (λ Low (Corresponding to the operating wavelength in the low-frequency band), the antenna feed point and ground point are both located on the top surface of the electronic device's base plate. The antenna's radiation efficiency in the low-frequency band is mainly covered by two modes, as follows: Figure 1b As shown in (a) and (b) in the figure. The circuit operates at a frequency of f. Low1 The resonant mode is a quarter-IFA mode, operating at frequency f. Low2The resonant mode is a quarter-unipolar mode, where f Low1 <f Low2 . Figure 1c This can be understood as the low-frequency antenna operating at mid-to-high frequencies (f). High The resonant mode is a three-quarters IFA mode of higher order mode. To facilitate the explanation of the performance of traditional low-frequency IFA antennas in the mid-to-high frequency range, Figure 1d This demonstrates a comparison scheme of a traditional IFA antenna operating at mid-to-high frequencies. Figure 1d The image in (a) shows the antenna operating in a quarter IFA mode at the intermediate frequency. Figure 1d Figure (b) shows the antenna operating in a quarter-pole mode at high frequencies. Figure 1e The image shows a comparison of the radiation efficiency of the three-quarters IFA mode and the quarter IFA mode in the mid-to-high frequency range. It can be seen that the radiation efficiency of the three-quarters IFA mode is lower than that of the quarter IFA mode in the mid-to-high frequency range. Figure 1f The image shows a comparison of SAR hotspot distribution in the three-quarter IFA mode and the quarter-IFA mode at intermediate frequency. It indicates that the three-quarter IFA mode at intermediate frequency contains a complete half-wave current distribution, and the current distribution is more concentrated on the antenna body, resulting in a relatively concentrated SAR hotspot distribution and exhibiting high SAR characteristics.
[0036] In summary, traditional low-frequency IFA antenna schemes struggle to achieve both good radiation and SAR performance in the mid-to-high frequency bands, while traditional mid-to-high frequency IFA antennas are limited by size and thus lack low-frequency performance. To address these issues, this application provides an antenna structure.
[0037] It should be noted that the low frequency band described in this application embodiment is 690MHz~960MHz, the mid frequency band is 1710MHz~2170MHz, the high frequency band is 2300MHz~2690MHz, and the mid-high frequency band is 1710MHz~2690MHz, which will not be repeated hereafter.
[0038] To better understand the technical solutions provided in the embodiments of this application, the relevant concepts involved in the embodiments of this application will be explained below.
[0039] Normalized SAR: The magnitude of the SAR peak value is closely related to the conducted power of the RF front-end and the antenna's own radiation efficiency (the actual radiated electromagnetic energy). To effectively compare SAR performance, the conducted power of the RF front-end and the antenna's own radiation efficiency need to be normalized to the same level before comparing the SAR peak values. Therefore, the concept of normalized SAR is introduced. Currently, the normalization standard is usually defined as RF conducted power 24dBm and antenna efficiency -5dB.
[0040] The electronic device provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings.
[0041] Please refer to Figure 2a , Figure 5 , Figures 6a to 6d as well as Figures 8a to 8d The electronic device provided in this application embodiment includes a base plate 20 and an antenna structure 10. The antenna structure 10 includes a first radiating stub 11, a second radiating stub 12, a third radiating stub 13, and a connecting stub 14. A first gap 101 is formed between the first radiating stub 11 and the second radiating stub 12, and a second gap 102 is formed between the second radiating stub 12 and the third radiating stub. The third radiating stub 13 is connected to the connecting stub 14, and the extension direction of the third radiating stub 13 is perpendicular to the extension direction of the connecting stub 14. The end of the connecting stub 14 away from the third radiating stub 13 is connected to the base plate 20. The base plate 20 serves as the ground of the antenna structure 10, that is, the connecting stub 14 is grounded. The total length of the first radiating stub 11, the second radiating stub 12, and the third radiating stub 13 is one-quarter of the operating wavelength of the low-frequency band, and the lengths of the first radiating stub 11, the second radiating stub 12, and the third radiating stub 13 are equal. A first tuning structure 16 is provided between the first radiating branch 11 and the second radiating branch 12, and a second tuning structure 17 is provided between the second radiating branch 12 and the third radiating branch 13. The second tuning structure 17 is used to block the mid-to-high frequency band.
[0042] like Figure 3 As shown, electronic devices typically include a back cover 22, a motherboard 24, a motherboard bracket 23, a housing 25, a display screen 26, and a decorative ring 21. The housing 25 typically includes a frame 27 and a base plate 20. The base plate 20 is a metal structure, and the frame 27 (also called the middle frame) can be metal or a non-conductive material such as plastic. The metal frame 27 can serve as an antenna radiator; or, if the frame 27 is made of plastic, the antenna radiator is typically a flexible printed circuit (FPC) metal structure mounted on the frame 27. Exemplarily, in this embodiment, the first radiating branch 11, the second radiating branch 12, and the third radiating branch 13 can be the metal frame 27 of the electronic device; or, if the frame 27 is made of a non-conductive material such as plastic, the first radiating branch 11, the second radiating branch 12, and the third radiating branch 13 can be an FPC metal structure mounted on the frame, which will not be elaborated further.
[0043] It should be noted that the equal lengths of the first radial branch 11, the second radial branch 12, and the third radial branch 13 can be understood as the lengths being completely identical or within a certain margin of error. For example, if the lengths of the first radial branch 11, the second radial branch 12, and the third radial branch 13 are within the range of 2cm ± 0.2cm, they can be considered to be equal in length.
[0044] Understandably, the total length of the first radiating stub 11, the second radiating stub 12, and the third radiating stub 13 is one-quarter of the operating wavelength of the low-frequency band. The antenna structure 10 provided in this application embodiment can be understood as an IFA antenna.
[0045] In this embodiment, a second gap 102 is provided between the second radiating branch 12 and the third radiating branch 13, and a second tuning structure 17 is provided between the second radiating branch 12 and the third radiating branch 13. For example, the second tuning structure 17 may include a capacitor and an inductor. In some embodiments, the second tuning structure 17 can also be understood as a filter. The second tuning structure 17 is used to block the mid-to-high frequency band, that is, the low frequency band can pass through. Optionally, the type of the second tuning structure 17 includes, but is not limited to: a low-pass tuning structure, a low-frequency bandpass tuning structure, and a mid-to-high frequency bandstop tuning structure. In some embodiments of this application, a mid-to-high frequency bandstop tuning structure is used as an example to illustrate the second tuning structure 17 of this application.
[0046] Please combine Figure 4a and Figure 4d The stopband of the second tuning structure 17 is located in the intermediate frequency band. In the intermediate frequency band, the second tuning structure 17 is equivalent to an open circuit; that is, the circuit formed by the second tuning structure 17, the first radiating stub 11, the second radiating stub 12, and the third radiating stub 13 is equivalent to forming a break (e.g., ...). Figure 2b As shown in (b), current cannot pass through this break; for example, current cannot flow from the third radiating stub 13 to the second radiating stub 12. Therefore, when the antenna structure 10 operates in the intermediate frequency band, an open circuit is formed at the second break 102, that is, the circuit between the third radiating stub 13 and the second radiating stub 12 is broken, and the current is mainly distributed in the third radiating stub 13, such as... Figure 4dAs shown in (a). Furthermore, a first gap 101 exists between the first radiating stub 11 and the second radiating stub 12, and a first tuning structure 16 is provided between the first radiating stub 11 and the second radiating stub 12, that is, the first tuning structure 16 is provided at the first gap 101, for example, the first tuning structure 16 is a capacitor. This first tuning structure 16 bridges the two suspended radiating stubs (that is, the first radiating stub 11 and the second radiating stub 12; a suspended stub can be understood as a stub without a ground point or a feed point) to form a complete suspended stub, which can reduce the equivalent electrical size of the suspended stub, making the half-wave resonant frequency of the suspended stub far away from the intermediate frequency band. Furthermore, the arrangement of the first gap 101 and the first tuning structure 16 can reduce the current peak in the middle of the half-wave resonant mode of the suspended stub. Therefore, the antenna structure 10 provided in this application embodiment mainly operates in the quarter IFA mode in the mid-frequency band. Compared with the three-quarter IFA mode of the traditional low-frequency IFA antenna in the mid-frequency band, the current of the antenna structure 10 provided in this application embodiment is more distributed on the base plate 20 and less distributed in the antenna body, thus forming a relatively dispersed SAR hotspot distribution. Therefore, the SAR performance of the antenna structure 10 provided in this application embodiment in the mid-frequency band is better than that of the traditional low-frequency IFA antenna in the mid-frequency band.
[0047] To better illustrate the beneficial effects of the antenna structure 10 provided in the embodiments of this application, the antenna structure 10 provided in the embodiments of this application will be referred to as the improved antenna structure A.
[0048] like Figure 4b As shown, compared to traditional low-frequency IFA antennas (schemes), the improved antenna structure A (also referred to as improved antenna scheme A) provided in this application embodiment has improved radiation efficiency in the mid-to-high frequencies, while also exhibiting good radiation efficiency in the low frequencies. Figure 4c As shown, the improved antenna structure A exhibits better SAR performance, with a dispersed SAR hotspot distribution. For example... Figure 4d As shown, the current in the improved antenna structure A is mainly distributed in the quarter-stub fed (i.e., the third radiating stub 13), while there is also a relatively weak current distribution in the other two suspended stubs (i.e., the first radiating stub 11 and the second radiating stub 12). Therefore, the improved antenna structure A mainly operates in quarter-IFA mode in the intermediate frequency band. Please refer to Table 1 below. Table 1 shows the normalized 5mmbody SAR of the top and back surfaces of the electronic device in the intermediate frequency band compared to the traditional intermediate frequency IFA antenna.
[0049] Table 1
[0050]
[0051]
[0052] As shown in Table 1, the improved antenna structure A provided in this application embodiment has better SAR performance in the mid-frequency band than the traditional low-frequency IFA antenna.
[0053] Please refer to Figure 5 In some embodiments, a switching structure SW is provided between the third radiating branch 13 and the feed structure 15, such as... Figure 5 As shown in (a); or, the first part of the third radiating branch 13 is connected to a switching structure, the end of the switching structure SW furthest from the third radiating branch 13 being grounded, as shown in (a). Figure 5 As shown in (b), the first portion is located between the end of the third radiating stub 13 near the second radiating stub 12 and the feed structure 15. The switching structure allows the impedance performance of the antenna structure 10 to switch between low-frequency and mid-to-high-frequency bands.
[0054] The antenna structure 10 provided in this application embodiment can cover low-frequency and mid-to-high-frequency bands, and has good SAR performance in the mid-frequency band. Compared with separate low-frequency and mid-to-high-frequency antennas, the antenna structure 10 provided in this application embodiment can effectively reduce costs and save space occupied by the antenna structure 10 in electronic devices, which is conducive to the development of thinner and lighter electronic devices.
[0055] Please continue to refer to Figure 2a In some embodiments, the third radiating stub 13 includes a first end close to the second radiating stub 12 and a second end away from the second radiating stub 12. A feed structure 15 connects the first and second ends, and the second end is connected to a connecting stub 14. Thus, the third radiating stub 13 and the connecting stub 14 form an L-shaped radiator. The connecting stub 14 is grounded, meaning the third radiating stub 13 can be grounded through the connecting stub 14, where the ground is the base plate 20 of the electronic device. In this way, the antenna structure 10 can achieve coverage of low-frequency and mid-to-high-frequency bands through a feed structure 15, a grounding point, and a switching structure, which helps to achieve low cost and high SAR performance of the antenna structure 10.
[0056] Optionally, such as Figures 6a-6bAs shown, in another embodiment, the antenna structure 10 provided in this application embodiment may further include a fourth radiating stub 18. The fourth radiating stub 18 is connected to the end of the third radiating stub 13 away from the second radiating stub 12, and the other end of the fourth radiating stub 18 is suspended. The length of the fourth radiating stub 18 is greater than one-eighth of the operating wavelength of the intermediate frequency band and less than one-quarter of the operating wavelength of the intermediate frequency band. In this embodiment, the third radiating stub 13, the connecting stub 14, and the fourth radiating stub 18 form a T-shaped radiator, thereby forming a T-shaped antenna structure in the intermediate frequency band, with the resonant mode being a common-mode mode. The arrangement of the fourth radiating stub 18 allows the resonant mode of the antenna structure 10 in the intermediate frequency band to further increase the proportion of its magnetic field (electric field) distribution on the side of the electronic device, making the field distribution of the antenna structure 10 more uniform in space, thereby forming a more dispersed SAR hotspot, which helps to further improve the SAR performance of the antenna structure 10.
[0057] Optionally, such as Figure 6a , Figure 6c (a) and Figure 6d As shown in (a), the third radiating stub 13 includes a first end near the second radiating stub 12 and a second end away from the second radiating stub 12. The second end is connected to the connecting stub 14 and the fourth radiating stub 18, and the feed structure 15 is connected between the first end and the second end. Alternatively, as shown in (a), Figure 6b , Figure 6c (b) and Figure 6d As shown in (b), the fourth radiating branch 18 is connected to the power supply structure 15, which is connected to the base plate 20.
[0058] Understandably, one end of connecting stub 14 is grounded, and connecting stub 14 can be connected to the second end of the third radiating stub 13; the power supply structure 15 can be connected between the first and second ends of the third radiating stub 13, or connected to the fourth radiating stub 18. For example... Figure 6a and Figure 6b As shown, the feed point (i.e. the connection position of the feed structure 15) and the ground point of the antenna structure 10 can be interchanged, so that the fourth radiating branch 18 can further reduce the overall size of the antenna structure 10 while keeping its length greater than one-eighth of the operating wavelength of the intermediate frequency band and less than one-quarter of the operating wavelength of the intermediate frequency band. This is beneficial to reducing the space occupied by the antenna structure 10 in electronic devices, and thus helps electronic devices to develop towards thinner and lighter designs.
[0059] Please refer to Figure 6e In some implementations, such as Figure 6e As shown in (b), a switch structure (SW) is provided between the third radiating stub 13 and the feed structure 15. Alternatively, as... Figure 6eAs shown in (a) and (d), a first portion of the third radiating stub 13 is connected to a switching structure SW, the end of the switching structure SW furthest from the third radiating stub 13 being grounded, and the first portion being located between the end of the third radiating stub 13 closest to the second radiating stub 12 and the feed structure 15. Alternatively, as... Figure 6e As shown in (c), a switch structure SW is provided at the end of the connecting stub 14 that is away from the third radiating stub 13, and the connection is grounded through the switch structure SW. The setting of the switch structure SW allows the impedance performance of the antenna structure 10 to switch between low-frequency and mid-to-high-frequency bands, effectively improving the performance of the antenna structure 10.
[0060] For better understanding, the antenna structure 10, including the fourth radiating stub 18, will be referred to below as improved antenna structure B (or improved antenna scheme B). Figure 7a As shown, the improved antenna (scheme) B has higher radiation efficiency in the high-frequency band compared to the improved antenna structure (scheme) A; as Figure 7b and Figure 7c As shown, the improved antenna structure B exhibits enhanced SAR performance in the mid-frequency band compared to the improved antenna structure A.
[0061] Please refer to Table 2, which shows the normalized 5mm body SAR comparison of improved antenna structure B and improved antenna structure A in the mid-frequency band on the back, top, and right sides of electronic devices.
[0062] Table 2
[0063]
[0064] As shown in Table 2, the normalized SAR of the improved antenna structure B on the right side is higher than that of the improved antenna structure A, indicating that the field strength of the improved antenna structure B on the right side is increased. According to the principle of energy conservation, the normalized SAR of the improved antenna structure B on the top and back surfaces is therefore reduced. The results shown in Table 2 indicate that the improved antenna structure B has a superior SAR performance in the mid-frequency band. That is, the addition of the fourth radiating stub 18 further improves the SAR performance of the antenna structure 10.
[0065] Alternatively, please refer to Figures 8c to 8eThe first radiating branch 11 and the second radiating branch 12 are located on the first surface 201 of the base plate 20, for example, the first surface 201 can be the side of the base plate facing away from the electronic device screen. The third radiating branch 13 and the fourth radiating branch 18 are located on the frame 27, that is, the third radiating branch 13 and the fourth radiating branch 18 are not located on the first surface 201. For example, if the frame 27 is made of metal, the third radiating branch 13 and the fourth radiating branch 18 are part of the frame 27. Or in some embodiments, the third radiating branch 13 and the fourth radiating branch 18 can also be additional metal branches attached to the frame 27. One end of the connecting branch 14 is connected to the third radiating branch 13, and the other end can be grounded through the connecting base plate 20. The first radiating branch 11 and the fourth radiating branch 18 are arranged adjacent to each other, and the second radiating branch 12 and the third radiating branch 13 are arranged adjacent to each other. For example, the projections of the third radiating branch 13 and the fourth radiating branch 18 relative to the first surface 201 may cover the first radiating branch 11 and the second radiating branch 12; or, the projections of the third radiating branch 13 and the fourth radiating branch 18 relative to the first surface 201 may also be located outside the first radiating branch 11 and the second radiating branch 12.
[0066] Or, such as Figure 8a and Figure 8b As shown, the third radiating branch 13, the connecting branch 14, and the fourth radiating branch 15 are located on the first surface 201 of the base plate 20, for example, the side of the base plate facing away from the electronic device screen. The first radiating branch 11 and the second radiating branch 12 are located on the frame 27, that is, the first radiating branch 11 and the second radiating branch 12 are not located on the first surface 201. For example, if the frame 27 is made of metal, the first radiating branch 11 and the second radiating branch 12 can be part of the frame 27; or in some embodiments, the first radiating branch 11 and the second radiating branch 12 can also be additional metal branches attached to the frame 27. The first radiating branch 11 is adjacent to the fourth radiating branch 18, and the second radiating branch 12 is adjacent to the third radiating branch 13. For example, in some embodiments, the projections of the first radiating branch 11 and the second radiating branch 12 relative to the first surface 201 are located within the third radiating branch 13 and the fourth radiating branch 18, or in some embodiments, the projections of the first radiating branch 11 and the second radiating branch 12 relative to the first surface 201 are located outside the third radiating branch 13 and the fourth radiating branch 18.
[0067] In such Figures 8a-8eIn the illustrated embodiment, the antenna structure 10 is a bent antenna structure, which can be understood as the radiating branches of the antenna structure 10 being arranged adjacent to each other vertically without contact. This arrangement can further reduce the space occupied by the antenna structure 10 within the electronic device, and is more conducive to the layout of the antenna structure 10 within the electronic device.
[0068] like Figure 8e As shown in (b), a switch structure (SW) is provided between the third radiating stub 13 and the feed structure 15. Alternatively, as... Figure 8e As shown in (a) and (d), a switch structure SW is connected to the end of the second radiating stub 12 near the second break 102, and the end of the switch structure away from the second radiating stub 12 is grounded. Alternatively, as... Figure 8e As shown in (c), a switching structure SW is provided at the end of the fourth radiating stub 18 near the third radiating stub 13, and is grounded through the switching structure SW. Understandably, the setting of the switching structure SW allows the impedance performance of the antenna structure 10 to switch between low-frequency and mid-to-high-frequency bands, effectively improving the performance of the antenna structure 10.
[0069] For better understanding, the above-described folded antenna structure 10 will be referred to below as the improved antenna structure C (or improved antenna scheme C). For example... Figure 9a As shown, the improved antenna structure (scheme) C can cover both low-frequency and mid-to-high-frequency bands; Figure 9b The figure shows the SAR hotspot distribution of the improved antenna structure C and the improved antenna structure B on the back 5mm body in the mid-frequency band. It shows that the SAR hotspot distribution of the improved antenna structure C is similar to that of the improved antenna structure B, and thus still maintains excellent SAR performance. Figure 9c The diagram shows the resonant mode current distribution of improved antenna structures C and B in the mid-frequency band. It indicates that the mid-frequency resonant mode of improved antenna structure C is the common-mode mode of a "T"-shaped antenna. The suspended stub (third radiating stub 13) also exhibits a reverse current distribution due to its coupling with the main antenna. The resonant mode of improved antenna structure C in the mid-frequency band is somewhat similar to that of improved antenna structure B in the mid-frequency band, thus explaining the similar SAR hotspot distribution of both structures in the mid-frequency band. Please refer to Table 3, which shows the normalized 5mm body SAR of improved antenna structure C on the top, back, and right sides.
[0070] Table 3
[0071]
[0072] As shown in Table 3, the SAR performance of the improved antenna structure C in the mid-frequency band is similar to that of the improved antenna structure B, meaning that the improved antenna structure C also has good SAR performance.
[0073] Optionally, in the antenna structure 10 provided in this application embodiment (including the improved antenna structure A, improved antenna structure B, and improved antenna structure C described above, which will not be repeated hereafter), the first tuning structure 16 includes a first capacitor, and the second tuning structure 17 includes a second capacitor and a first inductor, such as... Figure 2b , Figure 5 , Figure 6c , Figure 6d , Figure 8e As shown. The inclusion of the first capacitor helps to shorten the equivalent electrical dimension between the first radiating stub 11 and the second radiator, causing the half-wave resonant mode frequencies of the first radiating stub 11 and the second radiating stub 12 to be further away from the intermediate frequency band. The second tuning structure 17 includes a second capacitor and a first inductor, thereby enabling tuning of the operating frequency band of the third radiating stub 13.
[0074] Optionally, the capacitance of the first capacitor is 0.3pF to 2pF, the capacitance of the second capacitor is less than 2pF, and the inductance of the first inductor is greater than 3nH. The second tuning structure 17 can be a band-stop tuning structure, with its stopband frequency range located in the mid-frequency band, for example, 1.7GHz-2.2GHz. This configuration allows the antenna structure 10 to simultaneously cover both low-frequency and mid-to-high-frequency bands, thereby enabling miniaturization of the antenna structure 10 and reducing its footprint in electronic devices.
[0075] Alternatively, please refer to Figures 10a-10c In some embodiments, the first tuning structure 16 includes at least one recess 161 formed at one end of the first radiating stub 11 and at least one protrusion 162 formed at one end of the second radiating stub 12. The at least one protrusion 162 extends into the at least one recess 161 in a corresponding manner, and a first gap 101 is formed between the at least one recess 161 and the at least one protrusion 162. It is understood that the at least one recess 161 and the at least one protrusion 162 do not contact each other, but are spaced apart. The at least one protrusion 162 extends into the at least one recess 161 in a corresponding manner, thus creating an overlap between the first radiating stub 11 and the second radiating stub 12. This enables the design of an equivalent capacitance at the first gap 101, helping to further reduce the cost of the antenna structure 10.
[0076] For example, such as Figure 10a As shown, the first radial branch 11 includes a recess 161, and the second radial branch 12 includes a protrusion 162; as Figure 10bAs shown, the first radial branch 11 includes two recesses 161, and the second radial branch 12 includes two protrusions 162; as Figure 10c As shown, the first radial branch 11 includes a recess 161, and the second radial branch 12 includes a protrusion 162. In this embodiment, by adjusting the number of protrusions and recesses, and by adjusting the size of each protrusion and recess, the size of the overlapping area between the first radial branch 11 and the second radial branch 12 can be adjusted, thereby controlling the equivalent capacitance of the first fracture 101.
[0077] It should be noted that in some embodiments, the at least one protrusion 162 may be formed at one end of the first radial branch 11, and the at least one recess 162 may be formed at one end of the second radial branch 12. The design and beneficial effects are as described above and will not be repeated here.
[0078] Optionally, in some embodiments, the second tuning structure 17 includes a bent element 171, such as Figure 11a and Figure 11b As shown, the bent member 171 includes at least one bent portion. The bent member 171 is located near or within the second slit 102, and one end of the bent member 171 is electrically connected to the second radial branch 12, and the other end is electrically connected to the third radial branch 13. Exemplarily, the bent member is configured as follows... Figure 11a and Figure 11b As shown, this configuration allows for the implementation of an equivalent LC structure design via the bending element 171, eliminating the need to connect capacitors and inductors at the second slit 102, which helps to further reduce the cost of the antenna structure 10.
[0079] Please refer to Figure 12 In some embodiments, the first tuning structure 16 may adopt the above-described equivalent capacitance design, and the second tuning structure 17 may adopt the above-described equivalent LC structure design, thereby further reducing the cost of the antenna structure 10.
[0080] Alternatively, in some implementations, such as Figures 13-15 (The band-resistance type LC structure shown in the figure can be understood as the second tuning structure 17) As shown, the target radiation branch may include designs such as through holes, slots, and bends. The target radiation branch includes at least one of the first radiation branch 11, the second radiation branch 12, and the third radiation branch 13.
[0081] Optionally, the electronic devices provided in this application embodiment include, but are not limited to, products such as mobile phones, tablet computers, and smart wearable devices that are equipped with antenna structures 10.
[0082] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.
Claims
1. An electronic device, characterized in that, The antenna structure includes a base plate and an antenna structure. The antenna structure includes a first radiating stub, a second radiating stub, a third radiating stub, and a connecting stub. A first gap exists between the first and second radiating stubs, and a second gap exists between the second and third radiating stubs. The third radiating stub is connected to the connecting stub, and the extension direction of the third radiating stub is perpendicular to the extension direction of the connecting stub. The end of the connecting stub away from the third radiating stub is connected to the base plate. The base plate serves as the ground of the antenna structure. The total length of the first, second, and third radiating stubs is one-quarter of the operating wavelength of the low-frequency band, and the lengths of the first, second, and third radiating stubs are equal. The first radiating branch and the second radiating branch are provided with a first tuning structure, and the second radiating branch and the third radiating branch are provided with a second tuning structure. The second tuning structure is used to block the mid-to-high frequency band.
2. The electronic device according to claim 1, characterized in that, The third radiating stub includes a first end close to the second radiating stub and a second end away from the second radiating stub, with a power supply structure connecting the first end and the second end, and the second end being connected to the connecting stub.
3. The electronic device according to claim 1, characterized in that, It also includes a fourth radiating branch, one end of which is connected to the end of the third radiating branch that is away from the second radiating branch, and the other end of the fourth radiating branch is suspended. The length of the fourth radiating stub is greater than one-eighth of the operating wavelength of the intermediate frequency band and less than one-quarter of the operating wavelength of the intermediate frequency band.
4. The electronic device according to claim 3, characterized in that, The third radiating branch includes a first end close to the second radiating branch and a second end away from the second radiating branch. The second end is connected to the connecting branch and the fourth radiating branch. A power supply structure is connected between the first end and the second end; or, the fourth radiating branch is connected to a power supply structure.
5. The electronic device according to claim 3 or 4, characterized in that, The electronic device further includes a frame connected to the base plate, the first radiating branch and the second radiating branch are located on the first surface of the base plate, the third radiating branch and the fourth radiating branch are located on the frame, and the third radiating branch is adjacent to the second radiating branch, and the fourth radiating branch is adjacent to the first radiating branch.
6. The electronic device according to claim 3 or 4, characterized in that, The electronic device further includes a frame connected to the base plate. The third radiating branch, the connecting branch, and the fourth radiating branch are located on the first surface of the base plate. The first radiating branch and the second radiating branch are located on the frame, and the first radiating branch and the fourth radiating branch are arranged adjacent to each other, and the second radiating branch and the third radiating branch are arranged adjacent to each other.
7. The electronic device according to any one of claims 1-4, characterized in that, The first tuning structure includes a first capacitor, and the second tuning structure includes a second capacitor and a first inductor connected in parallel.
8. The electronic device according to claim 7, characterized in that, The capacitance of the first capacitor is 0.3pF to 2pF, the capacitance of the second capacitor is less than 2pF, and the inductance of the first inductor is greater than 3nH.
9. The electronic device according to any one of claims 1-4, characterized in that, The first tuning structure includes at least one recess formed at one end of the first radiating branch and at least one protrusion formed at one end of the second radiating branch. The at least one protrusion extends into the at least one recess in a corresponding manner, and the first gap is formed between the at least one recess and the at least one protrusion.
10. The electronic device according to any one of claims 1-4, characterized in that, The second tuning structure includes a bending member, which includes at least one bent portion. The bending member is located near or within the second fracture, and one end of the bending member is electrically connected to the second radiating branch, while the other end is electrically connected to the third radiating branch.