Antenna assembly, radio frequency module and electronic equipment

Abstract

The embodiment of the invention discloses an antenna assembly, a radio frequency module and electronic equipment, a radiation part is arranged on one side of a magnetic conduction part, and two radiation lines are arranged on the same plane at intervals so as to be coupled with a first magnetic conduction sheet. Therefore, the magnetic conduction part guides the radiation part to generate spatial distribution of the magnetic field, and the magnetic field intensity of the radiation part in a specific direction is improved. Therefore, the winding directions of the two first coils are configured to be opposite, and the ends, located on the inner sides of the first coils, of the two first coils form open-circuit ends. When a differential signal is fed into the radiation part through the two feed ends, the antenna assembly can effectively suppress common-mode interference of other antennas in the electronic equipment, and the anti-interference capability of the antenna assembly is improved. And on the other hand, the open circuit end arranged on the inner side of the first coil is not directly connected with the feed network, so that the radiation efficiency of the antenna assembly is improved. On the other hand, the two first coils are located in the area where the two radiation lines are far away from each other, and mutual interference of the two radiation lines is reduced.

Description

Technical Field

[0001] This invention relates to the field of near-field communication technology, and more particularly to an antenna assembly, a radio frequency module, and an electronic device. Background Technology

[0002] Near Field Communication (NFC) technology is used in electronic devices, enabling functions such as identity verification and mobile payments in devices like smartphones and smartwatches, thus improving user convenience. However, NFC antennas are prone to interference with other antennas on electronic devices, leading to performance degradation. Therefore, improving the interference resistance of NFC antennas and increasing their effective reading range has become a problem that needs to be solved. Summary of the Invention

[0003] In view of this, the present invention proposes several embodiments of an antenna assembly, a radio frequency module, and an electronic device, wherein at least one embodiment can solve the technical problem that NFC antennas are prone to mutual interference with other antennas of electronic devices, affecting antenna performance.

[0004] According to a first aspect of the present invention, an antenna assembly is provided, the antenna assembly comprising: The magnetic conductive part includes a first magnetic conductive sheet; and The radiating section is disposed on one side of the first magnetic sheet and includes two radiating lines. The two radiating lines are disposed at intervals on the same plane. Each radiating line includes a feed end and an open circuit end. The radiating line includes a first coil, one end of which is the open end, and the other end extends outward layer by layer in one direction. The magnetic fields generated by the two radiating lines act on and couple to the first magnetic sheet, the two first coils are wound in opposite directions, and the two first coils are located in regions where the two radiating lines are far apart from each other.

[0005] Furthermore, the radiating line also includes a second coil, the second coil including a first connecting end and the feeding end, the first connecting end being located between the first coil and the feeding end in the extension direction of the radiating line, and a coupling gap being formed on the opposite sides of the two second coils; The feed end extends outward layer by layer in one direction, and a layout area is formed inside the second coil. In the same radiating part, the second coil and the first coil are wound in the same direction, and the first coil is located in the layout area.

[0006] Furthermore, a clearance area is formed inside the second coil, and the two clearance areas are located between the two first coils.

[0007] Furthermore, the first coil includes a second connection terminal, the second connection terminal extending in the opposite direction to the open-circuit terminal; The radiating circuit also includes a third coil, which is located in the deployment area and has its two ends connected to the first connection end and the second connection end, respectively.

[0008] Furthermore, the third coil wraps around the first coil layer by layer, and the wrapping direction is consistent with that of the first coil; The deployment area includes a first deployment area and a second deployment area. The first deployment area is connected to the second deployment area, and the first deployment area, the second deployment area, and a portion of the second coil surround each other to form the clearance area. The two first deployment areas are located between the two second deployment areas. The third coil is positioned at the edge of the second deployment area and the first deployment area, with the first coil located at the center of the second deployment area.

[0009] Furthermore, the third coil includes a first connecting stub; The radiating section further includes a second connecting branch located in the clearance area. The two ends of the second connecting branch are connected to the two ends of the first connecting branch, and a portion of the clearance area is located between the first connecting branch and the second connecting branch.

[0010] Furthermore, the two power supply terminals are arranged opposite to each other and extend to the coupling gap; The two radial lines are mirror-symmetrical with respect to the center line, wherein the center line is equidistant from the two feed ends, and the center line extends along the length of the coupling gap.

[0011] Furthermore, the width of the radiating line is 0.2 mm; In the same radiating circuit, the spacing between the lines outside the first coil is 0.5 mm.

[0012] Furthermore, the magnetic conductive part also includes a second magnetic conductive sheet; The radiating part includes a flexible circuit board, and the two radiating lines are radiating patterns formed on the flexible circuit board. The first magnetic sheet and the second magnetic sheet are sandwiched in the area of ​​the flexible circuit board disposed on the radiating pattern.

[0013] Furthermore, the antenna assembly also includes a grounding plate, which is attached to the side of the first magnetic sheet opposite to the second magnetic sheet; The radiation pattern is projected onto the grounding plate in the same direction, and the radiation pattern is located inside the first magnetic sheet, the second magnetic sheet, and the grounding plate.

[0014] Furthermore, both the first and second magnetic conductive sheets are first rectangular sheets, with a length of 52 mm and a width of 15 mm. The grounding plate is a second rectangular plate, and the first rectangular plate has a length of 62.4 mm and a width of 18 mm; The length directions of the first rectangular piece and the second rectangular piece are consistent with the arrangement direction of the two radial lines.

[0015] Secondly, embodiments of the present invention also provide a radio frequency module, the radio frequency module comprising: The radio frequency circuit includes a first output port and a second output port: and An antenna assembly includes a magnetically conductive part and a radiating part. The magnetically conductive part includes a first magnetically conductive sheet. The radiating part is disposed on one side of the first magnetically conductive sheet and includes two radiating lines. The two radiating lines are spaced apart and disposed on the same plane. The two ends of the radiating lines are a feed end and an open-circuit end. The first output port and the second output port are electrically connected to the two feed ends, respectively. The radiating line includes a first coil, one end of which is the open end, and the other end extends outward layer by layer in one direction. The magnetic fields generated by the two radiating lines act on and couple to the first magnetic sheet. The two first coils are wound in opposite directions and are located on the side of the two radiating lines that are far apart from each other.

[0016] Furthermore, the radio frequency circuit is configured to output a first radio frequency signal through the first output port and a second radio frequency signal through the second output port, wherein the output impedance of the first output port and the second output port is 100Ω, and the phase difference between the first radio frequency signal and the second radio frequency signal is 180°.

[0017] Furthermore, the magnetic conductive part also includes a second magnetic conductive sheet; The radiating part includes a flexible circuit board, and the two radiating lines are radiating patterns formed on the flexible circuit board. The area of ​​the flexible circuit board disposed in the radiating pattern is sandwiched between the first magnetic conductive sheet and the second magnetic conductive sheet. The antenna assembly further includes a grounding plate, which is attached to the side of the first magnetic sheet that is away from the second magnetic sheet; The radiation pattern is located in the projection direction of the grounding plate, and the radiation pattern is simultaneously located inside the first magnetic conductive plate, the second magnetic conductive plate, and the grounding plate; The radio frequency circuit also includes a ground port: The flexible circuit board further includes a first path, a second path, and a third path. The first output port is connected to a power supply terminal through the first path, the second output port is connected to another power supply terminal through the second path, and the grounding plate is connected to the grounding port through the third path.

[0018] Thirdly, embodiments of the present invention also provide an electronic device, the electronic device comprising: The radio frequency module as described in the second aspect above.

[0019] The antenna assembly, radio frequency module, and electronic device of this invention have a radiating section disposed on one side of a magnetically conductive section, and two radiating lines spaced apart on the same plane for coupling with a first magnetically conductive sheet. This allows the magnetically conductive section to guide the spatial distribution of the magnetic field generated by the radiating section, increasing the magnetic field strength of the radiating section in a specific direction. Consequently, on one hand, the winding directions of the two first coils are configured in opposite directions, and one end located inside the first coil forms an open-circuit terminal. When a differential signal is fed into the radiating section through the two feed terminals, the antenna assembly can effectively suppress common-mode interference from other antennas in the electronic device, improving the anti-interference capability of the antenna assembly. On the other hand, the open-circuit terminal located inside the first coil is not directly connected to the feed network, thereby improving the radiation efficiency of the antenna assembly and effectively increasing the readout range. Furthermore, the two first coils are located in areas where the two radiating lines are far apart, reducing mutual interference between the two radiating lines and further increasing the effective readout range of the antenna assembly. Attached Figure Description

[0020] The above and other objects, features and advantages of the present invention will become clearer from the following description of embodiments of the invention with reference to the accompanying drawings, in which: Figure 1 This is a schematic diagram of one side of the antenna assembly according to an embodiment of the present invention; Figure 2 This is an exploded view of the antenna assembly according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the antenna assembly on the other side of an embodiment of the present invention; Figure 4 This is a schematic diagram showing the positional relationship between the two radiation lines in an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the radiation circuit according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of the second coil according to an embodiment of the present invention; Figure 7 This is a circuit diagram of the radio frequency module according to an embodiment of the present invention; Figure 8This is a schematic diagram of the radiation direction of the antenna assembly according to an embodiment of the present invention; Figure 9 yes Figure 5 Enlarged schematic diagram of region A in the middle; Figure 10 This is a schematic diagram of the magnetic field distribution of the antenna assembly according to the first embodiment of the present invention; Figure 11 This is a schematic diagram of the electric field distribution of the antenna assembly according to the first embodiment of the present invention; Figure 12 This is a schematic diagram of the magnetic field distribution of the antenna assembly according to the second embodiment of the present invention; Figure 13 This is a schematic diagram of the magnetic field distribution of the antenna assembly according to the third embodiment of the present invention; Figure 14 This is a simulation diagram of the return loss of the antenna assembly according to the first embodiment of the present invention; Figure 15 This is a simulation diagram of the impedance characteristics of the antenna assembly according to the first embodiment of the present invention.

[0021] Explanation of reference numerals in the attached figures: 1-Radiating section; 11-Radiating line; 111-Feeding end; 112-Open circuit end; 113-Coupling gap; 114-Second connecting stub; 115-Reading area; 12-Flexible circuit board; 121 - First pathway; 122 - Second pathway; 123 - Third pathway; 2-Magnetic conductive part; 21-First magnetic sheet; 22-Second magnetic sheet; 31-First coil; 32-Second coil; 33-Third coil; 331-First connecting stub; 41 - First connection end; 42 - Second connection end; 5-Deployment area; 51-First deployment area; 52-Second deployment area; 6. Clearance Zone; 7-Grounding plate; 71-Connecting areas; 8-RF circuit; 81-First output port; 82-Second output port; 83-Ground port; 84-Control chip; 85-Main control unit. Detailed Implementation

[0022] The present invention is described below based on embodiments, but the invention is not limited to these embodiments. In the detailed description of the invention below, certain specific details are described in detail. Those skilled in the art will fully understand the invention even without these details. To avoid obscuring the essence of the invention, well-known methods, processes, flows, elements, and circuits are not described in detail.

[0023] Furthermore, those skilled in the art should understand that the accompanying drawings provided herein are for illustrative purposes only and are not necessarily drawn to scale.

[0024] Unless the context explicitly requires it, words such as "including" or "contains" throughout the application should be interpreted as including rather than exclusive or exhaustive; that is, meaning "including but not limited to".

[0025] In the description of this invention, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0026] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0027] For ease of explanation, spatially related terms such as “inside,” “outside,” “below,” “below,” “lower,” “above,” “upper,” etc., are used herein to describe the relationship between one element or feature illustrated in the figure and another. It will be understood that spatially related terms may be intended to encompass different orientations of the device in use or operation besides those depicted in the figure. For example, if the device in the figure is flipped, an element described as “below” or “below” another element or feature would then be positioned “above” that other element or feature. Thus, the exemplified term “below” can encompass both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially related descriptive terms used herein should be interpreted accordingly.

[0028] Figure 1 This is a structural schematic diagram of one side of the antenna assembly in this embodiment. Figure 2 This is an exploded view of the antenna assembly in this embodiment. Figure 3 This is a schematic diagram of the other side of the antenna assembly in this embodiment. Figure 3 The second magnetic sheet 22 is not shown in the image. Figure 2 and Figure 3 The outline of the flexible circuit board 12 is shown with dashed lines.

[0029] In some implementations, such as Figures 1-3 As shown, the antenna assembly in this embodiment includes a radiating section 1, a magnetically conductive section 2, and a grounding plate 7. The radiating section 1 is disposed between the first magnetically conductive plate 21 and the second magnetically conductive plate 22. The radiating section 1 includes two radiating lines 11.

[0030] Figure 4 This is a schematic diagram showing the positional relationship between the two radiating lines 11 in this embodiment. Figure 5 This is a schematic diagram of the structure of the radiation circuit 11 in this embodiment. Figure 4 and Figure 5 The dashed line I in the diagram is the center line located between the two radial lines 11. Figure 5 The outline of the first coil 31 is shown with a thick dashed line, the outline of the second coil 32 is shown with a thick solid line, the outline of the third coil 33 is shown with a thin solid line, and the outline of the second connecting branch 114 is shown with a thin dashed line.

[0031] In some implementations, such as Figures 3-4 As shown, the radiating part 1 is disposed on one side of the first magnetic sheet 21, and two radiating lines 11 are disposed at intervals on the same plane. The radiating line 11 includes a feed end 111 and an open-circuit end 112. That is, the radiating line 11 extends from the feed end 111 to the open-circuit end 112. The radiating line 11 includes a first coil 31, one end of which is the open-circuit end 112, and the other end extends outward layer by layer in one direction.

[0032] In this embodiment, the first coil 31 is generally spiral-shaped. That is, in the cross-sectional direction parallel to the first magnetic sheet 21, the first coil 31 is wound in multiple layers in the form of a rectangular helix, with each layer spaced apart. The open end 112 is located inside the first coil 31 and is not connected to the feed network. The radiating part 1 is configured such that the magnetic fields generated by the two radiating lines 11 act on and couple to the first magnetic sheet 21, and the winding directions of the two first coils 31 are opposite. The two first coils 31 are located in regions where the two radiating lines 11 are far apart from each other, in order to increase the spacing between the two first coils 31.

[0033] Specifically, the antenna assembly can be an NFC antenna. The radiating section 1 is capable of transmitting and receiving NFC signals. This antenna assembly has reader mode, card mode, and peer-to-peer mode. A first magnetic sheet 21 is used to guide the magnetic field generated by the NFC antenna, increasing the magnetic field strength in a specific direction to improve the recognition success rate of the NFC antenna. The two radiating lines 11 are fed with differential signals from the differential circuit through two feed terminals 111. That is, one feed terminal 111 of the radiating line 11 is used to feed the positive phase signal of the differential signal, and the other feed terminal 111 of the radiating line 11 is used to feed the negative phase signal of the differential signal. Figure 2 As shown, the reading area 115 of the NFC antenna is located on the side of the radiating part 1 that is away from the first magnetic sheet 21.

[0034] Optionally, the antenna assembly also includes two coaxial cables, each corresponding to one of the two feed terminals 111. The inner conductors of the two coaxial cables are connected to the corresponding feed terminals 111, and the outer conductors are electrically connected to the grounding plate 7. Thus, the radiating section 1 is fed through the two coaxial cables.

[0035] In summary, in this embodiment, the antenna assembly has the radiating part 1 disposed on one side of the magnetically conductive part 2, and the two radiating lines 11 are spaced apart on the same plane to couple with the first magnetically conductive sheet 21. Thus, the magnetic field distribution generated by the radiating part 1 is guided by the magnetically conductive part 2, increasing the magnetic field strength of the radiating part 1 in a specific direction. Consequently, on one hand, the winding directions of the two first coils 31 are configured in opposite directions, and one end located inside the first coil 31 forms an open-circuit end 112. When the differential signal is fed into the radiating part 1 through the two feed ends 111, the antenna assembly can effectively suppress common-mode interference from other antennas in the electronic device, improving the anti-interference capability of the antenna assembly. On the other hand, the open-circuit end 112 located inside the first coil 31 is not directly connected to the feed network, thereby improving the radiation efficiency of the antenna assembly and effectively increasing the range of the readout area 115. Furthermore, the two first coils 31 are located in areas where the two radiating lines 11 are far apart, reducing mutual interference between the two radiating lines 11 and further increasing the effective readout area 115 of the antenna assembly.

[0036] Figure 6 This is a schematic diagram of the structure of the second coil 32 in this embodiment.

[0037] In some implementations, such as Figures 4-6As shown, the radiating line 11 also includes a second coil 32. The second coil 32 includes a first connecting end 41 and a feeding end 111. In the extending direction of the radiating line 11, the first connecting end 41 is located between the first coil 31 and the feeding end 111, and a coupling gap 113 is formed on the opposite sides of the two second coils 32. The feeding end 111 extends outward layer by layer in one direction, and a layout area 5 is formed inside the second coil 32. In the same radiating section 1, the second coil 32 and the first coil 31 are wound in the same direction, and the first coil 31 is located in the layout area 5.

[0038] In this embodiment, the first coil 31 and the second coil 32 of the same radiating line 11 are wound in the same direction, so that the magnetic fields generated by the first coil 31 and the second coil 32 can be superimposed to increase the magnetic field strength of the radiating line 11. The coupling gap 113 formed by the two second coils 32 allows the two radiating lines 11 to be superimposed, increasing the effective readout area 115 range of the antenna assembly.

[0039] Figure 7 This is a circuit diagram of the radio frequency module in this embodiment.

[0040] In some implementations, such as Figure 6 and Figure 7 As shown, a clearance area 6 is formed inside the second coil 32. Further referencing... Figure 4 As shown, the two clearance zones 6 are located between the two first coils 31. In this embodiment, the setting of radiating lines 11 in the clearance zone 6 is reduced or avoided to reduce the mutual interference between the two radiating lines 11 and ensure that the differential signal can be transmitted or received through the two radiating lines 11 respectively.

[0041] Optionally, the two radiating lines 11 are configured to read two NFC chips respectively to improve reading efficiency.

[0042] In some implementations, such as Figures 4-6 As shown, the first coil 31 includes a second connection terminal 42, which extends in the opposite direction to the open-circuit terminal 112. The radiating line 11 also includes a third coil 33, which is located in the deployment area 5 and has its two ends connected to the first connection terminal 41 and the second connection terminal 42, respectively. In this embodiment, the third coil 33 is used to increase the overall length of the radiating line 11, so that the radiating line 11 meets the length requirements of the NFC antenna.

[0043] In some implementations, such as Figures 4-5 As shown, the third coil 33 wraps around the first coil 31 layer by layer, and the wrapping direction is the same as that of the first coil 31. Further referencing... Figure 6As shown, the deployment area 5 includes a first deployment area 51 and a second deployment area 52. The first deployment area 51 is connected to the second deployment area 52, and the first deployment area 51, the second deployment area 52, and a portion of the second coil 32 surround each other to form a clearance area 6. The two first deployment areas 51 are located between the two second deployment areas 52. The third coil 33 is deployed at the edge of the second deployment area 52 and the first deployment area 51, and the first coil 31 is located at the center of the second deployment area 52.

[0044] In this embodiment, the third coil 33 located in the second deployment area 52 is used to make the lines on the side of the two radiating lines 11 that are far apart from each other denser, and the lines on the side that are close to each other sparser, so as to reduce the magnetic field strength on the side of the two radiating lines 11 that are close to each other. As a result, the mutual interference between the two radiating lines 11 is reduced, and the ineffective working area is reduced.

[0045] In some implementations, such as Figure 5 As shown, the third coil 33 includes a first connecting branch 331. The radiating part 1 also includes a second connecting branch 114, which is located in the clearance area 6. The two ends of the second connecting branch 114 are connected to the two ends of the first connecting branch 331, and a portion of the clearance area 6 is located between the first connecting branch 331 and the second connecting branch 114.

[0046] Figure 8 This is a schematic diagram of the radiation direction of the antenna assembly. The magnetic field strength in the areas indicated by the red, orange, yellow, green, and blue arrows decreases sequentially.

[0047] Specifically, such as Figure 5 As shown, the first connecting branch 331 includes two first segments, which are perpendicularly connected. The second connecting branch 114 includes two second segments, which are perpendicularly connected. The mutually distant ends of the two first segments are connected to the mutually distant ends of the two second segments to form a rectangular surface located in the clearance area 6. Figure 8 As shown, the magnetic field strength in the clearance area 6 is smaller than that in the deployment area 5. Simultaneously, the deployment area 5 is separated by the second connecting stubs 114, causing the magnetic field in the clearance area 6 between the two second connecting stubs 114 to radiate downwards, while the magnetic field in the deployment area 5 radiates upwards. Therefore, the induced current generated by the magnetic field of the right-side radiation line 11 on the left radiation line 11 will generate an induced magnetic field on the left radiation line 11. This induced magnetic field is located in the clearance area 6 between the two second connecting stubs 114, and its radiation direction is opposite to that of the reading area 115. Thus, by utilizing the clearance area 6 between the two second connecting stubs 114, the induced magnetic field is concentrated on both sides of the coupling gap 113, reducing interference from the induced magnetic field to the reading area 115. At the same time, the radiation line 11 can generate self-resonance within the operating frequency band to improve radiation efficiency.

[0048] In some implementations, such as Figure 4 As shown, the two feed terminals 111 are positioned opposite each other and extend to the coupling slot 113. The two radiating lines 11 are positioned relative to the center line (e.g., Figure 4 (As shown by dashed line I in the diagram) Mirror symmetry. The center line is equidistant from both feed terminals 111, and extends along the length of the coupling slot 113. In this embodiment, the two radiating lines 11 start from the two feed terminals 111 and extend from the coupling slot 113 in opposite directions. Simultaneously, the two mirror symmetric radiating lines 11 correspond to the positive and negative phase signals of the differential signal, respectively, enabling the radiating section 1 to radiate the positive and negative phase signals separately and superimpose them at the near-field position. Alternatively, this allows the antenna assembly to acquire NFC signals at the near-field position.

[0049] In some implementations, such as Figure 2 and Figure 3 As shown, the magnetic conductive part 2 also includes a second magnetic conductive sheet 22. The radiating part 1 includes a flexible circuit board 12, and two radiating lines 11 are radiating patterns formed on the flexible circuit board 12. The first magnetic conductive sheet 21 and the second magnetic conductive sheet 22 are sandwiched in the area of ​​the flexible circuit board 12 that is disposed in the radiating pattern.

[0050] It is easy to understand that the signal in the near-field region of the NFC antenna is mainly in the form of a magnetic field. Therefore, setting the radiation pattern between the first magnetic sheet 21 and the second magnetic sheet 22 can effectively guide the magnetic field distribution, enhance the magnetic field strength, and further improve the read / write distance.

[0051] Furthermore, the antenna assembly also includes a grounding plate 7. The grounding plate 7 is attached to the side of the first magnetic sheet 21 facing away from the second magnetic sheet 22. The radiation pattern is located on the inner side of the first magnetic sheet 21, the second magnetic sheet 22, and the grounding plate 7 in the projection direction of the grounding plate 7.

[0052] Specifically, the grounding piece 7 includes a grounding area 71. The grounding piece 7 can be made of materials such as copper or aluminum alloy. The first magnetic sheet 21 and the second magnetic sheet 22 can be ferrite. The grounding area 71 is offset from the first magnetic sheet 21, and in the arrangement direction of the two feed terminals 111, the grounding area 71 is located between the two feed terminals 111. This grounding area 71 can be connected to the grounding port 83 of the RF circuit 8 (e.g., ...). Figure 7 As shown, a ground plane is formed for the antenna assembly. This grounding plate 7 isolates the antenna assembly from surrounding radio frequency devices from electromagnetic interference. Simultaneously, the first magnetic plate 21 and the second magnetic plate 22 guide the magnetic field generated by the radiating section 1 through the grounding plate 7 perpendicularly, reducing magnetic diffusion loss. On the other hand, the magnetic plate 2 blocks the induced eddy currents generated in the grounding plate 7, preventing the resonant frequency of the radiating section 1 from shifting.

[0053] Figure 9 yes Figure 5 A magnified view of region A in the middle.

[0054] In some implementations, such as Figure 5 , Figure 7 and Figure 9 As shown, the width of the radiating line 11 is 0.2 mm (e.g., Figure 9 (As shown in L1). Furthermore, in the same radiating line 11, the line spacing outside the first coil 31 is 0.5mm (as shown in L1). Figure 9 (As shown in L2). In contrast, the spacing between the layers of the first coil 31 gradually increases from the outside to the inside. In this embodiment, by configuring the line width and spacing, the impedance of the radiating line 11 is configured to 100Ω, so that the antenna assembly can be directly connected to the control chip 84 without setting an impedance matching network or impedance transformation network between the control chip 84 and the antenna assembly.

[0055] In some implementations, such as Figures 1-3 As shown, both the first magnetic conductive sheet 21 and the second magnetic conductive sheet 22 are first rectangular sheets, each with a length of 52 mm and a width of 15 mm. The grounding sheet 7 is a second rectangular sheet, with a length of 62.4 mm and a width of 18 mm. The length directions of the first and second rectangular sheets are aligned with the arrangement direction of the two radiating lines 11. This ensures that the first magnetic conductive sheet 21 and the second magnetic conductive sheet 22 can cover both sides of the radiating section 1, preventing eddy currents from being generated on the grounding sheet 7 and enhancing the magnetic field strength in a specific direction of the radiating section 1.

[0056] In some implementations, such as Figure 4 As shown, the coupling slot 113 includes a first slot and a second slot along its length. Two feed terminals 111 are located at the end of the first slot furthest from the second slot. The width of the first slot is 2 mm (as shown by distance L3 in the figure), and the width of the second slot is 4 mm (as shown by distance L4 in the figure). In this embodiment, by adjusting the widths of the first and second slots, the coupling strength of the two radiating lines 11 is adjusted to increase the effective area of ​​the antenna assembly readout region 115.

[0057] Table 1 shows a parameter comparison between the antenna assembly in the above embodiments and the single-ended NFC antenna. As can be seen from the table, the read / write distance, temperature drift, and anti-interference parameters of the antenna assembly have been effectively improved. Among them, the CMRR (Common Mode Rejection Ratio) is greater than 30dB, indicating that the antenna assembly can effectively suppress radio frequency interference from cellular networks of mobile phones or smartwatches.

[0058] In an alternative implementation, the antenna assembly in the above embodiments can be applied to a radio frequency module. For example... Figure 8As shown, the RF module also includes an RF circuit 8. The RF circuit 8 includes a first output port 81 and a second output port 82.

[0059] Specifically, the RF circuit 8 includes a control chip 84, a main control unit 85, and a differential circuit. The main control unit 85 is connected to the NRSTPD and IRQ pins of the control chip 84. The NRSTPD pin is used to implement reset and power control functions, and the IRQ pin is used to implement interrupt requests. The TX1 pin is used to send a positive phase signal to one feed terminal 111 (i.e., the first output port 81), and the TX2 pin is used to send a negative phase signal to the other feed terminal 111 (i.e., the second output port 82). The TVSS pin is used to connect to the grounding area 71 to provide ground to the antenna assembly. The VMID pin is used to provide a reference voltage, and the RX pin is used to receive the NFC signal acquired by the antenna assembly. In addition, multiple capacitors and inductors placed between the TX1, TX2, and TVSS pins and the antenna assembly form a differential circuit for differential calculation.

[0060] In summary, in this embodiment, the RF module has the radiating section 1 disposed on one side of the magnetically conductive section 2, and the two radiating lines 11 are spaced apart on the same plane to couple with the first magnetically conductive sheet 21. Thus, the magnetic field distribution generated by the radiating section 1 is guided by the magnetically conductive section 2, increasing the magnetic field strength of the radiating section 1 in a specific direction. Consequently, on one hand, the winding directions of the two first coils 31 are configured in opposite directions, and one end located inside the first coil 31 forms an open-circuit end 112. When the differential signal is fed into the radiating section 1 through the two feed ends 111, the antenna assembly can effectively suppress common-mode interference from other antennas in the electronic device, improving the anti-interference capability of the antenna assembly. On the other hand, the open-circuit end 112 located inside the first coil 31 is not directly connected to the feed network, thereby improving the radiation efficiency of the antenna assembly and effectively increasing the range of the readout area 115. Furthermore, the two first coils 31 are located in areas where the two radiating lines 11 are far apart, reducing mutual interference between the two radiating lines 11 and further increasing the effective readout area 115 of the antenna assembly.

[0061] Furthermore, the radio frequency (RF) circuit 8 is configured to output a first RF signal through a first output port 81 and a second RF signal through a second output port 82, with the output impedance of both the first and second output ports 81 being 100Ω. The phase difference between the first and second RF signals is 180°. In this embodiment, the RF module operates at a frequency of 13.56 MHz, and its power consumption is reduced by 40% compared to the aforementioned single-ended NFC antenna. Simultaneously, a differential circuit improves the RF module's anti-interference capability.

[0062] In some implementations, such as Figures 1-6As shown, the magnetically conductive part 2 further includes a second magnetically conductive sheet 22. The radiating part 1 includes a flexible circuit board 12, and two radiating lines 11 are radiating patterns formed on the flexible circuit board 12. The flexible circuit board 12 is disposed in the area of ​​the radiating pattern and sandwiched between the first magnetically conductive sheet 21 and the second magnetically conductive sheet 22. The antenna assembly also includes a grounding sheet 7, which is attached to the side of the first magnetically conductive sheet 21 facing away from the second magnetically conductive sheet 22. In the projection direction of the grounding sheet 7, the radiating pattern is simultaneously located inside the first magnetically conductive sheet 21, the second magnetically conductive sheet 22, and the grounding sheet 7. Further referencing... Figure 3 and Figure 7 As shown, the RF circuit 8 also includes a ground port 83. The flexible circuit board 12 also includes a first path 121, a second path 122 and a third path 123. The first output port 81 is connected to a feed terminal 111 through the first path 121, the second output port 82 is connected to another feed terminal 111 through the second path 122, and the grounding piece 7 is connected to the ground port 83 through the third path 123.

[0063] In this embodiment, the flexible circuit board 12 includes a conductive pattern, which includes a first path 121, a second path 122, and a third path 123. The third path 123 of the conductive pattern faces the first magnetic sheet 21, so that one end of the third path 123 can be electrically connected to the grounding area 71. This optimizes the connection method between the radio frequency circuit 8 and the antenna assembly.

[0064] Figure 10 This is a schematic diagram of the magnetic field distribution of the antenna assembly provided in the first embodiment. Figure 11 This is a schematic diagram of the electric field distribution of the antenna assembly provided in the first embodiment. The antenna assembly in the first embodiment has the same form as the antenna assembly described above.

[0065] like Figure 10 and Figure 11 As shown, the open-circuit terminal 112 of the antenna assembly is not connected to the feed network. The magnetic field strength of the antenna assembly reaches 2030 A / m in the second deployment area 52, and the electric field strength reaches 717.2 V / m in the second deployment area 52.

[0066] Figure 12 This is a schematic diagram of the magnetic field distribution of the antenna assembly according to the second embodiment of the present invention. Figure 13 This is a schematic diagram of the magnetic field distribution of the antenna assembly according to the third embodiment of the present invention.

[0067] The second embodiment differs from the first embodiment in that the two open terminals 112 are connected to each other, thus short-circuiting the two radiating lines 11. The third embodiment differs from the second embodiment in that LC network impedance matching is further performed on the antenna assembly of the second embodiment.

[0068] like Figure 12As shown, after connecting the two open terminals 112, the maximum value of the magnetic field distribution drops from 2858 A / m to 84 A / m. Figure 13 As shown, after impedance matching, the maximum magnetic field strength is 871.698 A / m. Although this is nearly 10 times higher than the second embodiment, it is still much lower than the maximum magnetic field strength of the first embodiment. Therefore, the RF module in the above embodiments can effectively improve the transmission and reception performance of NFC signals.

[0069] Figure 14 This is a simulation diagram of the return loss of the antenna assembly in the first embodiment.

[0070] like Figure 14 As shown, in the 13.56MHz to 14.16MHz frequency band, the return loss is basically below -15dB, indicating that the NFC antenna of the first embodiment has good transmission efficiency.

[0071] Figure 15 This is a simulation diagram of the impedance characteristics of the antenna assembly in the first embodiment.

[0072] like Figure 15 As shown, m1 corresponds to the real impedance value of 91.37Ω at 13.7MHz, and m2 corresponds to the imaginary impedance value of -0.798Ω at 13.7MHz. The impedance of the antenna assembly is Z = 91.3715Ω. j0.798Ω. This demonstrates that the antenna assembly exhibits good impedance characteristics at the 13.7MHz frequency point.

[0073] The radio frequency module in the above embodiments can be applied to electronic devices, including but not limited to mobile phones, smartwatches, or tablets.

[0074] In summary, in this embodiment, the electronic device has a radiating section 1 disposed on one side of the magnetically conductive section 2, and two radiating lines 11 spaced apart on the same plane for coupling with the first magnetically conductive sheet 21. Thus, the magnetic field distribution generated by the radiating section 1 is guided by the magnetically conductive section 2, increasing the magnetic field strength of the radiating section 1 in a specific direction. Consequently, on one hand, the winding directions of the two first coils 31 are configured in opposite directions, and one end located inside the first coil 31 forms an open-circuit end 112. When a differential signal is fed into the radiating section 1 through the two feed ends 111, the antenna assembly can effectively suppress common-mode interference from other antennas in the electronic device, improving the anti-interference capability of the antenna assembly. On the other hand, the open-circuit end 112 located inside the first coil 31 is not directly connected to the feed network, thereby improving the radiation efficiency of the antenna assembly and effectively increasing the range of the readout area 115. Furthermore, the two first coils 31 are located in areas where the two radiating lines 11 are far apart, reducing mutual interference between the two radiating lines 11 and further increasing the effective readout area 115 of the antenna assembly.

[0075] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. For those skilled in the art, the present invention can be modified and varied in various ways. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of protection of the present invention.

Claims

1. An antenna assembly, characterized in that, The antenna assembly includes: The magnetic conductive part includes a first magnetic conductive sheet; and The radiating section is disposed on one side of the first magnetic sheet and includes two radiating lines. The two radiating lines are disposed at intervals on the same plane. Each radiating line includes a feed end and an open circuit end. The radiating line includes a first coil, one end of which is the open end, and the other end extends outward layer by layer in one direction. The magnetic fields generated by the two radiating lines act on and couple to the first magnetic sheet, the two first coils are wound in opposite directions, and the two first coils are located in regions where the two radiating lines are far apart from each other.

2. The antenna assembly according to claim 1, characterized in that, The radiating line further includes a second coil, which includes a first connecting end and the feeding end. In the extension direction of the radiating line, the first connecting end is located between the first coil and the feeding end, and the opposite sides of the two second coils form a coupling gap. The feed end extends outward layer by layer in one direction, and a layout area is formed inside the second coil. In the same radiating part, the second coil and the first coil are wound in the same direction, and the first coil is located in the layout area.

3. The antenna assembly according to claim 2, characterized in that, A clearance area is formed inside the second coil, and the two clearance areas are located between the two first coils.

4. The antenna assembly according to claim 3, characterized in that, The first coil includes a second connection terminal, the second connection terminal extending in the opposite direction to the open-circuit terminal; The radiating circuit also includes a third coil, which is located in the deployment area and has its two ends connected to the first connection end and the second connection end, respectively.

5. The antenna assembly according to claim 4, characterized in that, The third coil wraps around the first coil layer by layer, and the wrapping direction is the same as that of the first coil. The deployment area includes a first deployment area and a second deployment area. The first deployment area is connected to the second deployment area, and the first deployment area, the second deployment area, and a portion of the second coil surround each other to form the clearance area. The two first deployment areas are located between the two second deployment areas. The third coil is positioned at the edge of the second deployment area and the first deployment area, with the first coil located at the center of the second deployment area.

6. The antenna assembly according to claim 5, characterized in that, The third coil includes a first connecting stub; The radiating section further includes a second connecting branch located in the clearance area. The two ends of the second connecting branch are connected to the two ends of the first connecting branch, and a portion of the clearance area is located between the first connecting branch and the second connecting branch.

7. The antenna assembly according to any one of claims 2-6, characterized in that, The two power supply terminals are positioned opposite each other and extend into the coupling gap; The two radial lines are mirror-symmetrical with respect to the center line, wherein the center line is equidistant from the two feed ends, and the center line extends along the length of the coupling gap.

8. The antenna assembly according to any one of claims 1-6, characterized in that, The width of the radiating line is 0.2 mm; In the same radiating circuit, the spacing between the lines outside the first coil is 0.5 mm.

9. The antenna assembly according to any one of claims 1-6, characterized in that, The magnetic conductive part also includes a second magnetic conductive sheet; The radiating part includes a flexible circuit board, and the two radiating lines are radiating patterns formed on the flexible circuit board. The first magnetic sheet and the second magnetic sheet are sandwiched in the area of ​​the flexible circuit board disposed on the radiating pattern.

10. The antenna assembly according to claim 9, characterized in that, The antenna assembly further includes a grounding plate, which is attached to the side of the first magnetic sheet that is away from the second magnetic sheet; The radiation pattern is projected onto the grounding plate in the same direction, and the radiation pattern is located inside the first magnetic sheet, the second magnetic sheet, and the grounding plate.

11. The antenna assembly according to claim 10, characterized in that, Both the first magnetic conductive sheet and the second magnetic conductive sheet are first rectangular sheets, with a length of 52mm and a width of 15mm. The grounding plate is a second rectangular plate, and the first rectangular plate has a length of 62.4 mm and a width of 18 mm; The length directions of the first rectangular piece and the second rectangular piece are consistent with the arrangement direction of the two radial lines.

12. A radio frequency module, characterized in that, The radio frequency module includes: The radio frequency circuit includes a first output port and a second output port: and An antenna assembly includes a magnetically conductive part and a radiating part. The magnetically conductive part includes a first magnetically conductive sheet. The radiating part is disposed on one side of the first magnetically conductive sheet and includes two radiating lines. The two radiating lines are spaced apart and disposed on the same plane. The two ends of the radiating lines are a feed end and an open-circuit end. The first output port and the second output port are electrically connected to the two feed ends, respectively. The radiating line includes a first coil, one end of which is the open end, and the other end extends outward layer by layer in one direction. The magnetic fields generated by the two radiating lines act on and couple to the first magnetic sheet. The two first coils are wound in opposite directions and are located on the side of the two radiating lines that are far apart from each other.

13. The radio frequency module according to claim 12, characterized in that, The radio frequency circuit is configured to output a first radio frequency signal through the first output port and a second radio frequency signal through the second output port, wherein the output impedance of the first output port and the second output port is 100Ω, and the phase difference between the first radio frequency signal and the second radio frequency signal is 180°.

14. The radio frequency module according to claim 12, characterized in that, The magnetic conductive part also includes a second magnetic conductive sheet; The radiating part includes a flexible circuit board, and the two radiating lines are radiating patterns formed on the flexible circuit board. The area of ​​the flexible circuit board disposed in the radiating pattern is sandwiched between the first magnetic conductive sheet and the second magnetic conductive sheet. The antenna assembly further includes a grounding plate, which is attached to the side of the first magnetic sheet that is away from the second magnetic sheet; The radiation pattern is located in the projection direction of the grounding plate, and the radiation pattern is simultaneously located inside the first magnetic conductive plate, the second magnetic conductive plate, and the grounding plate; The radio frequency circuit also includes a ground port: The flexible circuit board further includes a first path, a second path, and a third path. The first output port is connected to a power supply terminal through the first path, the second output port is connected to another power supply terminal through the second path, and the grounding plate is connected to the grounding port through the third path.

15. An electronic device, characterized in that, The electronic device includes: The radio frequency module according to any one of claims 12-14.

Images