Electromagnetic shielding structures and electronic equipment

Abstract

This application discloses an electromagnetic shielding structure and electronic device, relating to the field of electromagnetic interference, for reducing the electromagnetic coupling between modules within the electromagnetic shielding structure. The electromagnetic shielding structure comprises a shielding frame, a shielding cover, and a tuning network. The shielding cover engages with the shielding frame. The shielding frame comprises a first cavity and a second cavity, the first and second cavities separated by a reinforcing rib. The first cavity is used to accommodate a first module, and the second cavity is used to accommodate a second module. The reinforcing rib is grounded through the tuning network.

Description

Technical Field

[0001] The present application relates to the field of electromagnetic interference, and in particular to an electromagnetic shielding structure and electronic equipment. Background Art

[0002] In electronic devices, electromagnetic shielding structures are used to shield modules that generate or are susceptible to electromagnetic interference (such as direct current-direct current (DC-DC) power modules and memory). This prevents the electromagnetic interference signals generated by these modules from affecting the normal operation of other components, and vice versa. However, shielding multiple modules in the same space can increase electromagnetic coupling between modules, creating new electromagnetic interference issues. Summary of the Invention

[0003] Embodiments of the present application provide an electromagnetic shielding structure and an electronic device, which are used to reduce the electromagnetic coupling between modules in the electromagnetic shielding structure.

[0004] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0005] In a first aspect, an electromagnetic shielding structure is provided, comprising: a shielding frame, a shielding cover, and at least one tuning network, wherein the shielding cover is buckled with the shielding frame, the shielding frame comprises a first cavity and a second cavity, the first cavity and the second cavity are separated by reinforcing ribs, the first cavity is used to accommodate a first module, and the second cavity is used to accommodate a second module; the reinforcing ribs are grounded through the tuning network.

[0006] The electromagnetic shielding structure provided in the embodiment of the present application connects a tuning network between the reinforcement ribs of the electromagnetic shielding structure and the ground, thereby changing the resonant state of the electromagnetic shielding structure (the resonant frequency remains unchanged, and the S parameter of the resonant frequency becomes smaller), suppressing the electromagnetic coupling between the first module and the second module and the reinforcement ribs, thereby suppressing the electromagnetic coupling between the first module and the second module, and reducing the electromagnetic coupling degree between the modules in the electromagnetic shielding structure.

[0007] In one possible implementation, the location on the reinforcement where the electric field is strongest in the electromagnetic simulation is grounded via a tuning network, thereby balancing cost and the effect of suppressing electromagnetic coupling.

[0008] In a possible implementation, positions on the reinforcement ribs spaced at least a predetermined distance apart are grounded via a tuning network, which can enhance the effect of suppressing electromagnetic coupling.

[0009] In one possible implementation, the tuning network includes at least one of the following: a capacitor, an inductor, a capacitor and an inductor connected in parallel, and a capacitor and an inductor connected in series. This implementation provides several possible structures of the tuning network.

[0010] In one possible embodiment, when the tuning network includes a capacitor, or a capacitor and an inductor connected in parallel, the tuning network is used to suppress electromagnetic coupling between the first module and the second module at frequencies greater than 1 GHz. The corresponding resonant network can be selected based on the frequency band of the electromagnetic coupling to be suppressed.

[0011] In one possible embodiment, when the tuning network includes an inductor, or a capacitor and an inductor connected in series, the tuning network is used to suppress electromagnetic coupling between the first module and the second module at frequencies less than 1 GHz. The corresponding resonant network can be selected based on the frequency band of the electromagnetic coupling to be suppressed.

[0012] In one possible embodiment, the capacitance is greater than or equal to 2 pF. In this case, the tuning network can suppress electromagnetic coupling between the first and second modules at frequencies greater than 1 GHz. The tuning network significantly changes the S parameters between the first module and the reinforcement ribs. In certain frequency bands, the S parameters can even approach those of a structure without electromagnetic shielding. This significantly reduces the electromagnetic coupling between the first and second modules, significantly suppressing electromagnetic coupling between modules within the electromagnetic shielding structure.

[0013] In one possible embodiment, the inductance is greater than or equal to 8.2 nH. In this case, the tuning network can suppress electromagnetic coupling between the first and second modules at frequencies below 1 GHz. The tuning network significantly changes the S parameters between the first module and the reinforcement ribs. In certain frequency bands, the S parameters can even approach those of a structure without electromagnetic shielding. This significantly reduces the electromagnetic coupling between the first and second modules, significantly suppressing electromagnetic coupling between modules within the electromagnetic shielding structure.

[0014] In a second aspect, an electronic device is provided, comprising a first module, a second module, and the electromagnetic shielding structure described in the first aspect and any embodiment thereof, wherein the first cavity of the electromagnetic shielding structure is used to accommodate the first module, and the second cavity of the electromagnetic shielding structure is used to accommodate the second module.

[0015] The technical effects of the second aspect refer to the technical effects of the first aspect and any of its embodiments and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application;

[0017] Figure 2A schematic structural diagram of an electromagnetic shielding structure provided in an embodiment of the present application;

[0018] Figure 3 A schematic diagram of S parameters of a shielding frame and a shielding cover before and after being fastened together, provided in an embodiment of the present application;

[0019] Figure 4 A schematic diagram of S parameters between an electromagnetic interference source and a victim at different locations provided in an embodiment of the present application;

[0020] Figure 5 A schematic diagram of S parameters between another electromagnetic interference source and interfered objects at different locations provided in an embodiment of the present application;

[0021] Figure 6 A schematic diagram of S parameters between another electromagnetic interference source and interfered objects at different locations provided in an embodiment of the present application;

[0022] Figure 7 A schematic diagram of S parameters between another electromagnetic interference source and interfered objects at different positions provided in an embodiment of the present application;

[0023] Figure 8 A schematic diagram of a simulation model and S parameters provided in an embodiment of the present application;

[0024] Figure 9 A schematic diagram of the electric field distribution of a simulation model and a physical model provided in an embodiment of the present application;

[0025] Figure 10 A schematic diagram of the magnetic field distribution of a simulation model and a physical model provided in an embodiment of the present application;

[0026] Figure 11 A schematic diagram of S parameters of a reinforcing rib grounded through a shielding cover at different positions provided in an embodiment of the present application;

[0027] Figure 12 A schematic diagram of S parameters of another embodiment of the present application wherein a reinforcing rib is grounded at different positions through a shielding cover;

[0028] Figure 13 A schematic diagram of electric field distribution and magnetic field distribution of a first module in the absence of a shielding frame provided in an embodiment of the present application;

[0029] Figure 14 A schematic diagram of electric field distribution and magnetic field distribution of a first module when a shielding frame is provided in an embodiment of the present application;

[0030] Figure 15 A schematic diagram of S parameters when a reinforcing rib and a shielding cover are short-circuited and insulated, provided in an embodiment of the present application;

[0031] Figure 16 A schematic diagram of the S parameters of a capacitor connected between a reinforcement rib and ground provided in an embodiment of the present application;

[0032] Figure 17 A schematic diagram of the S parameters of an inductor connected between a reinforcing rib and ground provided in an embodiment of the present application;

[0033] Figure 18 A schematic diagram of S parameters of a capacitor and an inductor connected in series between a reinforcing rib and a ground provided in an embodiment of the present application;

[0034] Figure 19 A schematic diagram of S parameters of a capacitor and an inductor connected in parallel between a reinforcing rib and a ground provided in an embodiment of the present application;

[0035] Figure 20 A schematic structural diagram of another electromagnetic shielding structure provided in an embodiment of the present application;

[0036] Figure 21 A schematic diagram of electric field distribution and magnetic field distribution when different positions of a reinforcement rib provided in an embodiment of the present application are grounded through a resonant network;

[0037] Figure 22 A schematic diagram of S parameters between the first module and different positions of the reinforcement rib after the reinforcement rib is grounded through a resonant network provided in an embodiment of the present application;

[0038] Figure 23 A schematic diagram of the S parameter between a first module and a position g on a reinforcing rib provided in an embodiment of the present application;

[0039] Figure 24 A schematic diagram of the S parameter between a first module and a position h on a reinforcing rib provided in an embodiment of the present application;

[0040] Figure 25 A schematic diagram of a shielding cover provided in an embodiment of the present application that is made of a flexible conductive material;

[0041] Figure 26 A schematic diagram of the S parameter between the first module and a position g on the reinforcing rib when the flexible conductive material is insulated from the reinforcing rib, provided in an embodiment of the present application;

[0042] Figure 27 A schematic diagram of the S parameter between the first module and the position g on the reinforcing rib when the flexible conductive material and the reinforcing rib are short-circuited, provided in an embodiment of the present application;

[0043] Figure 28A schematic diagram of the S parameter between the first module and a position g on the reinforcing rib when the flexible conductive material is insulated from the vertical portion of the reinforcing rib and short-circuited with other portions of the reinforcing rib, provided in an embodiment of the present application;

[0044] Figure 29 A schematic diagram of the S parameters between the first module and the position g on the reinforcing rib when the flexible conductive material is insulated from the horizontal portion of the reinforcing rib and short-circuited with other portions of the reinforcing rib is provided in an embodiment of the present application. DETAILED DESCRIPTION

[0045] First, some concepts involved in this application are described.

[0046] The terms "first", "second", etc. involved in the embodiments of the present application are only used to distinguish features of the same type and cannot be understood as indicating relative importance, quantity, order, etc.

[0047] The terms "exemplary" or "for example" in the embodiments of this application are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "exemplary" or "for example" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0048] The terms "coupling" and "connection" involved in the embodiments of this application should be understood in a broad sense. For example, they may refer to a physical direct connection, or an indirect connection achieved through electronic devices, such as a connection achieved through resistors, inductors, capacitors or other electronic devices.

[0049] Electromagnetic interference (EMI): EMI refers to any electromagnetic signal that interferes with the normal operation of electronic equipment, systems, or circuits. This interference can come from natural sources (such as lightning) or man-made sources (such as electronic equipment and radio transmitters).

[0050] Electromagnetic shielding: Electromagnetic shielding refers to the use of electromagnetic shielding structures or shielding materials to wrap the module to block or weaken the propagation of electromagnetic fields, thereby preventing electromagnetic interference.

[0051] Scattering parameter (abbreviated as S parameter): S parameter S(b,a) represents the signal at position b (complex vector ) and the signal at position a (complex vector ) , a and b can be the same or different. When a and b are the same, the S parameter S(b,a) represents the reflection coefficient, that is, how much energy is reflected back to position a. When a and b are different, the S parameter S(b,a) represents the coupling coefficient, that is, how much energy is coupled from position a to position b. A larger value indicates more signal is coupled to position b. For example, assuming position 1 is the input end of the signal and positions 2 and 3 are the coupling ends of the signal, then S(1,1) (abbreviated as S11) represents the reflection coefficient, S(2,1) (abbreviated as S21) and S(3,1) (abbreviated as S31) represent the coupling coefficient.

[0052] An embodiment of the present application provides an electronic device that can be mobile or fixed. The electronic device can be deployed on land (e.g., indoors or outdoors, handheld or vehicle-mounted), on water (e.g., on ships), or in the air (e.g., on airplanes or balloons). The electronic device can be referred to as user equipment (UE), access terminal, terminal unit, subscriber unit, terminal station, mobile station (MS), mobile station, terminal agent, or terminal device. For example, the electronic device can be a mobile phone, tablet computer, laptop computer, smart bracelet, smart screen, smart watch, headset, smart speaker, terminal in industrial control, terminal in self-driving, terminal in remote medical, terminal in smart grid, terminal in transportation safety, terminal in smart city, terminal in smart home, etc. The embodiments of the present application do not limit the specific type and structure of the electronic device. The following describes a possible structure of the electronic device.

[0053] Figure 1 This is a schematic structural diagram of an electronic device provided in an embodiment of the present application. The electronic device 100 includes a first module 21 , a second module 22 , an electromagnetic shielding structure 23 , a printed circuit board (PCB) 24 , and optionally a battery 25 .

[0054] The electromagnetic shielding structure 23, the first module 21, and the second module 22 are mounted on a PCB 24. The first module 21 and the second module 22 are modules that generate or are susceptible to electromagnetic interference, such as direct current (DC-DC) power modules and memory. A battery 25 is used to power the first and second modules 21 and 22.

[0055] The electromagnetic shielding structure 23 is made of conductive material. The electromagnetic shielding structure 23 is used to shield the first module 21 and the second module 22 that generate electromagnetic interference or are susceptible to electromagnetic interference, to prevent the electromagnetic interference signals generated by these modules from affecting the normal operation of other devices, or to prevent the electromagnetic interference signals generated by other devices from affecting the normal operation of these modules.

[0056] Figure 2 This is a schematic diagram of an electromagnetic shielding structure provided in an embodiment of the present application. Electromagnetic shielding structure 23 includes a shielding frame 231 and a shielding cover 232. Shielding frame 231 is made of rigid metal, and shielding cover 232 can be made of rigid metal or a flexible conductive material such as copper foil or conductive fabric.

[0057] The shield frame 231 includes a first cavity 2311, a second cavity 2312, and reinforcing ribs 2313. The reinforcing ribs 2313, also known as support ribs, enhance the structural strength of the shield frame 231. The first cavity 2311 and the second cavity 2312 are the perforated areas on the shield frame 231. The first cavity 2311 and the second cavity 2312 are separated by the reinforcing ribs 2313. The first cavity 2311 accommodates the first module 21, while the second cavity 2312 accommodates the second module 22.

[0058] It should be noted that Figure 2 A in the middle is a top view of the shielding frame 231, the shielding cover 232, the first cavity 2311, the second cavity 2312, the reinforcing rib 2313, the first module 21 and the second module 22; Figure 2 B is a top view of the electromagnetic shielding structure 23; Figure 2 Center C is a side view of the shielding frame 231 , the shielding cover 232 , the first cavity 2311 , the second cavity 2312 , the reinforcing rib 2313 , the first module 21 , and the second module 22 .

[0059] When the shielding frame 231 and the shielding cover 232 are buckled together, the first module 21 and the second module 22 are shielded in the electromagnetic shielding structure 23. Since the first module 21 generates electromagnetic resonance with the second module 22 through the electromagnetic shielding structure 23, the electromagnetic coupling between the first module 21 and the second module 22 increases, causing new electromagnetic interference problems.

[0060] For example, Figure 3 A schematic diagram of the S parameters of a shielding frame and a shielding cover before and after being fastened together provided in an embodiment of the present application. Figure 3 A is the S parameter when the shielding frame 231 and the shielding cover 232 are not fastened together. Figure 3 Where B is the S parameter when the shield frame 231 and shield cover 232 are fastened together. S11 refers to the reflection coefficient of the first module 21 itself, and S22 refers to the reflection coefficient of the second module 22 itself. S21 is the S parameter (i.e., coupling coefficient) between the first module 21 and the second module 22 (signal transmission from the first module 21 to the second module 22), while S12 is the S parameter (i.e., coupling coefficient) between the second module 22 and the first module 21 (signal transmission from the second module 22 to the first module 21).

[0061] As can be seen, compared to when the shielding frame 231 and shielding cover 232 are not fastened together, when the shielding frame 231 and shielding cover 232 are fastened together, S21 and S12 increase by approximately 20 dB in the mid-to-high frequency region (e.g., greater than 1 GHz). This indicates that the electromagnetic coupling between the first module 21 and the second module 22 increases by approximately 20 dB. This indicates that the electromagnetic shielding structure does increase the electromagnetic coupling between internal modules and reduce the isolation between them.

[0062] Because the first module 21 generates electromagnetic resonance with the second module 22 through the electromagnetic shielding structure 23, the electromagnetic coupling between the first module 21 and the second module 22 increases. To this end, the embodiments of the present application provide an electromagnetic shielding structure and an electronic device. By connecting a tuning network, such as a capacitor, an inductor, a series capacitor and inductor, a parallel capacitor and inductor, etc., between the reinforcing rib 2313 of the electromagnetic shielding structure 23 and the ground, the resonant state of the electromagnetic shielding structure 23 is changed (the resonant frequency remains unchanged, and the S parameter of the resonant frequency decreases), the electromagnetic coupling between the first module 21 and the second module 22 and the reinforcing rib 2313 is suppressed, and the electromagnetic coupling between the first module 21 and the second module 22 is suppressed, thereby reducing the electromagnetic coupling between the modules within the electromagnetic shielding structure 23.

[0063] The electromagnetic coupling problem inside the electromagnetic shielding structure 23 is analyzed below. Figure 4 Middle A, Figure 5 Middle A, Figure 6 Middle A, Figure 7 The simulation model shown in Figure 1.

[0064] Figure 4 This is a schematic diagram of the S parameters between an electromagnetic interference source and a disturbed object at different positions provided in an embodiment of the present application. Figure 4As shown in Figure A, it is assumed that a microstrip line is constructed at the location of the second module 22. One end of the microstrip line is connected to a 50 ohm load, and the other end of the microstrip line is excitation. This structure can be equivalent to a current loop, which is used to simulate the electromagnetic interference source. Several positions (positions 2 to 6) are selected around the second module 22 in the shielding frame 231, and a metal line is constructed at each position to simulate the affected object affected by electromagnetic interference. The S parameters at these positions are as follows: Figure 4 As shown in Figure B, S11 represents the S parameter (i.e., reflection coefficient) of the second module 22, S21 represents the S parameter (i.e., coupling coefficient) between the second module 22 and position 2, S31 represents the S parameter (i.e., coupling coefficient) between the second module 22 and position 3, S41 represents the S parameter (i.e., coupling coefficient) between the second module 22 and position 4, S51 represents the S parameter (i.e., coupling coefficient) between the second module 22 and position 5, and S61 represents the S parameter (i.e., coupling coefficient) between the second module 22 and position 6.

[0065] Figure 5 This is a schematic diagram of S parameters between another electromagnetic interference source and the interfered objects at different positions provided by the embodiment of the present application. Figure 5 As shown in A, assuming that Figure 4 On the basis of A in FIG, the shielding cover 232 is buckled on the second module 22 and positions 2 to 6 to form an electromagnetic shielding structure. The second module 22 and positions 2 to 6 are included in the electromagnetic shielding structure. The S parameters of these positions are as follows: Figure 5 As shown in B.

[0066] By comparison Figure 4 and Figure 5 It can be seen that when the shielding frame 231 and shielding cover 232 are fastened together, the second module 22 and positions 2 through 6 are included in the electromagnetic shielding structure. The S parameter (i.e., coupling coefficient) between the second module 22 and positions 2 through 6 increases by approximately 20 dB. This indicates that the electromagnetic shielding structure does increase the electromagnetic coupling between internal modules and reduce the isolation between them.

[0067] Figure 6 This is a schematic diagram of S parameters between another electromagnetic interference source and the interfered objects at different positions provided in the embodiment of the present application. Figure 6 As shown in Figure A, it is assumed that a microstrip line is constructed at the location of the first module 21, one end of the microstrip line is connected to a 50 ohm load, and the other end of the microstrip line is excited. This structure can be equivalent to a current loop for simulating electromagnetic interference sources. Figure 4 At the same positions (position 2 to position 6) in A, a metal wire is constructed to simulate the affected object by electromagnetic interference. The S parameters at these positions are as follows Figure 6As shown in B, S11 represents the S parameter (i.e., reflection coefficient) of the first module 21, S21 represents the S parameter (i.e., coupling coefficient) between the first module 21 and position 2, S31 represents the S parameter (i.e., coupling coefficient) between the first module 21 and position 3, S41 represents the S parameter (i.e., coupling coefficient) between the first module 21 and position 4, S51 represents the S parameter (i.e., coupling coefficient) between the first module 21 and position 5, and S61 represents the S parameter (i.e., coupling coefficient) between the first module 21 and position 6.

[0068] Figure 7 This is a schematic diagram of S parameters between another electromagnetic interference source and the interfered objects at different positions provided in the embodiment of the present application. Figure 7 As shown in A, assuming that Figure 6 On the basis of A in FIG, the shielding cover 232 is buckled on positions 2 to 6 to form an electromagnetic shielding structure. Positions 2 to 6 are included in the electromagnetic shielding structure. The S parameters of these positions are as follows: Figure 7 As shown in B.

[0069] By comparison Figure 6 and Figure 7 It can be seen that when shielding frame 231 and shielding cover 232 are fastened together, positions 2 through 6 are included in the electromagnetic shielding structure. The S parameters (i.e., coupling coefficients) between the first module 21 and positions 2 through 6 remain essentially unchanged. This indicates that the electromagnetic shielding structure does not increase the electromagnetic coupling between the external module and the internal modules, nor does it change the isolation between the internal modules.

[0070] In order to further analyze the electromagnetic coupling problem inside the electromagnetic shielding structure, Figure 2 The physical model shown in A is scanned on the surface of the physical model using a near-field probe to test the electromagnetic field distribution in the near field and obtain the S parameter (ie, coupling coefficient) between the first module 21 and the second module 22.

[0071] Figure 8 A schematic diagram of a simulation model and S parameters provided in the embodiment of the present application. Figure 8 The simulation model shown in A is used to simulate Figure 2 The structure shown in A. For example, Figure 8 The first module 21 in A is used as an electromagnetic interference source to simulate Figure 2 The first module 21 in. Figure 8 The second module 22 in A is used as a disturbed body to simulate Figure 2 The second module 22 in. Figure 8 The shielding frame 231 in the middle A is used to simulate Figure 2 The shielding frame 231 in Figure 8 The reinforcement 2313 of A is used to simulate Figure 2 Reinforcement 2313 in.

[0072] Figure 8 As shown in Figure B, by continuously adjusting the parameters of the simulation model, the S parameters between the first module 21 and the second module 22 in the simulation model are made the same as the S parameters between the first module 21 and the second module 22 in the physical model, thereby achieving consistency and accuracy between the simulation model and the physical model, and facilitating the simulation and analysis of the electromagnetic coupling of the physical model through the simulation model.

[0073] The measured S11 refers to the reflection coefficient of the first module 21 in the physical model, and the measured S22 refers to the reflection coefficient of the second module 22 in the physical model. The simulated S11 refers to the reflection coefficient of the first module 21 in the simulation model, and the simulated S22 refers to the reflection coefficient of the second module 22 in the simulation model. The measured S21 refers to the coupling coefficient between the first module 21 and the second module 22 in the physical model, and the measured S12 refers to the coupling coefficient between the second module 22 and the first module 21 in the physical model. The simulated S21 refers to the coupling coefficient between the first module 21 and the second module 22 in the simulation model, and the simulated S12 refers to the coupling coefficient between the second module 22 and the first module 21 in the simulation model.

[0074] Figure 9 Schematic diagram of the electric field distribution of a simulation model and a physical model provided in an embodiment of the present application. Figure 10 This is a schematic diagram of the magnetic field distribution of a simulation model and a physical model provided in the embodiment of the present application. In order to verify the consistency and accuracy between the simulation model and the physical model, Figure 2 The physical model shown in A is scanned with a near-field probe to test the electromagnetic field distribution in the near field. Figure 9 The X-axis electromagnetic field distribution shown in B, and Figure 10 The Y-axis electromagnetic field distribution shown in B. Figure 8 The simulation model shown in A is scanned in the near field to obtain Figure 9 The X-axis electromagnetic field distribution shown in A, and Figure 10 The Y-axis electromagnetic field distribution shown in A. By comparison Figure 9 A and B, and contrast Figure 10 In Figures A and B, it can be seen that the X-axis electromagnetic field distribution of the simulation model is consistent with that of the physical model, and the X-axis electromagnetic field distribution of the simulation model is consistent with that of the physical model, both of which are similar to the electromagnetic field generated by the magnetic dipole.

[0075] Furthermore, during testing of the physical model, it was discovered that changing the shape of the ribs 2313 of the shielding frame 231 affects the electromagnetic coupling between the modules within the electromagnetic shielding structure. When the shielding frame 231 and the shielding cover 232 are fastened together, if the ribs 2313 are insulated from the shielding cover 232, pressing the shielding cover 232 will also change the electromagnetic coupling between the first module 21 and the second module 22. If the ribs 2313 are grounded through the shielding cover 232, pressing the shielding cover 232 will essentially maintain the electromagnetic coupling between the first module 21 and the second module 22. This indicates that the gap between the ribs 2313 and the shielding cover 232 affects the electromagnetic coupling between the first module 21 and the second module 22.

[0076] The following simulation analyzes the effect of the grounding of the reinforcing rib 2313 on the electromagnetic coupling between the first module 21 and the second module 22 .

[0077] Figure 11 This is a schematic diagram of the S parameters of a reinforcing rib grounded through a shielding cover at different locations provided in an embodiment of the present application. Figure 11 As shown in Figure A, by changing the grounding position of the reinforcing rib 2313 (position a-position d), the shielding cover is pressed to produce deformation, so that the reinforcing rib 2313 is grounded through the shielding cover at different positions. Figure 11 As shown in Figure B, when the reinforcing ribs 2313 are grounded at positions a to d, compared with when the reinforcing ribs 2313 are not grounded, although the S parameter S21 (i.e., the coupling coefficient) between the first module 21 and the second module 22 changes, the impact is relatively small. This is because the first module 21 and the second module 22 are not electromagnetically coupled through the reinforcing ribs 2313 at these positions.

[0078] Figure 12 A schematic diagram of S parameters of another embodiment of the present application wherein a reinforcing rib is grounded through a shielding cover at different locations. Figure 12 As shown in Figure A, the position of the second module 22 is changed so that the second module 22 is located below the reinforcing rib 2313. By changing the grounding position of the reinforcing rib 2313 (position a-position d), the deformation caused by pressing the shielding cover is simulated, so that the reinforcing rib 2313 is grounded through the shielding cover at different positions. Figure 12 As shown in Figure B, when the reinforcing ribs 2313 are grounded at positions a to d, the S parameter S21 (i.e., the coupling coefficient) between the first module 21 and the second module 22 changes significantly compared to when the reinforcing ribs 2313 are not grounded. This is because electromagnetic coupling occurs between the first module 21 and the second module 22 through the reinforcing ribs 2313 at these positions.

[0079] Figure 13 A schematic diagram of the electric field distribution and magnetic field distribution of the first module in the absence of a shielding frame is provided in an embodiment of the present application. Figure 14 A schematic diagram of the electric field distribution and magnetic field distribution of the first module when a shielding frame is provided in an embodiment of the present application. Figure 13 A in the middle is a schematic diagram of the electric field distribution of the first module 21 when there is no shielding frame. Figure 13 B is a schematic diagram of the magnetic field distribution of the first module 21 when there is no shielding frame. Figure 14 A in the middle is a schematic diagram of the electric field distribution of the first module 21 when the shielding frame 231 is present. Figure 14 Figure B shows the magnetic field distribution of the first module 21 with the shielding frame 231. Darker colors indicate stronger electric or magnetic field strength. As can be seen, the addition of the shielding frame significantly enhances the electromagnetic energy in the area where the reinforcing ribs 2313 are located. This indicates that electromagnetic energy from the first module 21 is coupled to the second port through the reinforcing ribs 2313, degrading the isolation between the first module 21 and the second port.

[0080] Figure 15 This is a schematic diagram of the S parameters of a reinforcement rib and a shielding cover when they are short-circuited and insulated, provided in an embodiment of the present application. In order to analyze the electromagnetic coupling between the first module 21 and the reinforcement rib 2313, the reinforcement rib 2313 is fastened to the shielding cover. The S parameters between the first module 21 and the reinforcement rib 2313 when the reinforcement rib 2313 is short-circuited and insulated from the shielding cover are compared, where S31 represents Figure 22 The S parameter between the first module 21 and the reinforcement rib 2313 at position g, S41 represents Figure 22 The S parameter between the first module 21 and the reinforcing rib 2313 at position h in FIG. As can be seen, when reinforcing rib 2313 is insulated from the shielding case, the S parameter (coupling coefficient) differs in some frequency bands compared to when the two are short-circuited, but the overall trend is not significant. Therefore, short-circuiting the two does not significantly alter the electromagnetic coupling between the first module 21 and the reinforcing rib 2313, nor does it significantly change the isolation between the first module 21 and the second module 22.

[0081] like Figure 16-Figure 19 As shown, the following analysis is made on whether the isolation between the first module 21 and the second module 22 can be reduced by connecting different tuning networks between the reinforcement rib 2313 and the ground (that is, connecting the reinforcement rib 2313 to the ground through different tuning networks). The tuning network may include at least one of the following: a capacitor, an inductor, a capacitor and an inductor in series, or a capacitor and an inductor in parallel. S31 represents Figure 22 The S parameter between the first module 21 and the reinforcement rib 2313 at position g.

[0082] Figure 16A schematic diagram of the S parameters of a capacitor connected between a reinforcement rib and the ground is provided in an embodiment of the present application. When there is an electromagnetic shielding structure, the S parameter S31 changes in the same trend when the reinforcement rib 2313 is directly grounded or not grounded. However, compared with the case without an electromagnetic shielding structure, the S parameter S31 increases by about 20-30dB as a whole, that is, the electromagnetic coupling between the first module 21 and the reinforcement rib 2313 is obvious, which will cause the electromagnetic coupling between the first module 21 and the second module 22 to increase significantly. When the reinforcement rib 2313 is grounded through a 0.1pF capacitor, due to the small capacitance, the S parameter S31 changes in the same trend as when the reinforcement rib 2313 is directly grounded or not grounded, and the inhibitory effect on the electromagnetic coupling between the modules inside the electromagnetic shielding structure is not obvious. When the capacitance is greater than or equal to 2pF, for example, 2pF, 5pF or 18pF, the S parameter between the first module 21 and the reinforcement rib 2313 will be significantly changed. In a specific frequency band, it is even close to the S parameter when there is no electromagnetic shielding structure, thereby significantly reducing the electromagnetic coupling between the first module 21 and the second module 22, and having a more obvious inhibitory effect on the electromagnetic coupling between the modules inside the electromagnetic shielding structure.

[0083] It should be noted that the frequency bands in which different capacitors suppress electromagnetic coupling may be different. In actual engineering, it is necessary to simulate the frequency bands of electromagnetic coupling suppressed by various capacitors, and determine which capacitor to use in combination with the frequency band of the power consumption coupling that needs to be suppressed. For example, if you want to suppress electromagnetic coupling at 5.2GHz, you can use a 2pF capacitor or an 18pF capacitor. If you want to suppress electromagnetic coupling at 2.8GHz, you can use a 5pF capacitor. If you want to suppress electromagnetic coupling at 1.5GHz, you can use an 18pF capacitor. If you want to suppress electromagnetic coupling in multiple frequency bands, you can connect multiple capacitors in parallel, and each capacitor suppresses the electromagnetic coupling in the corresponding frequency band. In the embodiment of the present application, the capacitance is greater than or equal to 2pF. According to Figure 16 It can be seen that the reinforcing rib 2313 is grounded via a capacitor, which can suppress electromagnetic coupling greater than 1 GHz between the first module 21 and the second module 22 .

[0084] Figure 17A schematic diagram of the S parameters of an inductor connected between a reinforcement rib and ground provided in an embodiment of the present application. When the reinforcement rib 2313 is grounded through a 0.1nH inductor or a 1nH inductor, due to the small inductance, the S parameter S31 maintains the same trend as when the reinforcement rib 2313 is not grounded, and the inhibitory effect on the electromagnetic coupling between the modules within the electromagnetic shielding structure is not obvious. When the inductance is greater than or equal to 8.2nH, for example, 8.2nH, 18nH, 33nH, 68nH or 100nH, the S parameters between the first module 21 and the reinforcement rib 2313 will be significantly changed. In a specific frequency band, it is even close to the S parameters when there is no electromagnetic shielding structure, thereby significantly reducing the electromagnetic coupling between the first module 21 and the second module 22, and having a more obvious inhibitory effect on the electromagnetic coupling between the modules within the electromagnetic shielding structure.

[0085] It should be noted that the frequency bands in which different inductors suppress electromagnetic coupling may be different. In actual engineering, it is necessary to simulate the frequency bands of electromagnetic coupling suppressed by various inductors, and determine which inductor to use in combination with the frequency band of the power consumption coupling that needs to be suppressed. For example, if you want to suppress electromagnetic coupling at 0.6GHz, you can use an 8.2nH inductor, 18nH inductor, 33nH inductor, 68nH inductor or 100nH inductor. In the embodiment of the present application, the inductor is greater than or equal to 8.2nH. According to Figure 17 It can be seen that the reinforcing rib 2313 can suppress the electromagnetic coupling less than 1 GHz between the first module 21 and the second module 22 through inductive grounding.

[0086] Figure 18 A schematic diagram of the S parameters of a capacitor and an inductor connected in series between the reinforcing rib and the ground provided in an embodiment of the present application. If a capacitor and an inductor are connected in series between the reinforcing rib 2313 and the ground for tuning, that is, the reinforcing rib 2313 is grounded through the capacitor and the inductor connected in series, it is similar to connecting an inductor between the reinforcing rib 2313 and the ground for tuning. For details, refer to Figure 17 For example, when the inductance is 0.1nH or 1nH, the S parameter S31 is consistent with the trend of the ungrounded reinforcement rib 2313, and the inhibitory effect on the electromagnetic coupling between the modules inside the electromagnetic shielding structure is not obvious. When the inductance is greater than or equal to 8.2nH, such as 8.2nH, 18nH, 33nH, 68nH or 100nH, the S parameter between the first module 21 and the reinforcement rib 2313 will be significantly changed. In a specific frequency band, it is even close to the S parameter when there is no electromagnetic shielding structure, thereby significantly reducing the electromagnetic coupling between the first module 21 and the second module 22, and the inhibitory effect on the electromagnetic coupling between the modules inside the electromagnetic shielding structure is more obvious. In the embodiment of the present application, the inductance is greater than or equal to 8.2pF. According to Figure 18It can be seen that the reinforcing rib 2313 is grounded through the capacitor and inductor connected in series, which can suppress the electromagnetic coupling between the first module 21 and the second module 22 at a frequency less than 1 GHz.

[0087] It should be noted that in Figure 18 In the table, the numbers in brackets are as shown in Table 1, indicating that the capacitors and inductors use the corresponding values. For example, S31(1) indicates that the capacitors and inductors use the values corresponding to number 1 in Table 1.

[0088] Table 1

[0089]

[0090] Figure 19 A schematic diagram of the S parameters of a capacitor and an inductor connected in parallel between the reinforcement rib and the ground provided in an embodiment of the present application. If a capacitor and an inductor are connected in parallel between the reinforcement rib 2313 and the ground for tuning, that is, the reinforcement rib 2313 is grounded through a capacitor and an inductor connected in parallel, it is similar to connecting a capacitor between the reinforcement rib 2313 and the ground for tuning. For details, refer to Figure 16 Related description. When the capacitance is 0.1pF, due to the small capacitance, the S parameter S31 is consistent with the trend of change when the reinforcement rib 2313 is directly grounded and not grounded, and the inhibitory effect on the electromagnetic coupling between the modules inside the electromagnetic shielding structure is not obvious. When the capacitance is greater than or equal to 2pF, for example, 2pF, 5pF or 18pF, the S parameter between the first module 21 and the reinforcement rib 2313 will be significantly changed. In a specific frequency band, it is even close to the S parameter when there is no electromagnetic shielding structure, thereby significantly reducing the electromagnetic coupling between the first module 21 and the second module 22, and the inhibitory effect on the electromagnetic coupling between the modules inside the electromagnetic shielding structure is more obvious.

[0091] It should be noted that in Figure 19 In the table, the numbers in brackets are as shown in Table 1, indicating that the capacitors and inductors use the corresponding values. For example, S31(1) indicates that the capacitors and inductors use the values corresponding to number 1 in Table 1.

[0092] In addition, by comparison Figure 16-Figure 19It can be seen that connecting a capacitor between the reinforcing rib 2313 and the ground for tuning, or connecting a capacitor and an inductor in parallel between the reinforcing rib 2313 and the ground for tuning, significantly reduces the electromagnetic coupling between the first module 21 and the second module 22 in high-frequency bands (e.g., greater than 1 GHz), that is, the electromagnetic coupling is more significantly suppressed. Connecting an inductor between the reinforcing rib 2313 and the ground for tuning, or connecting a capacitor and an inductor in series between the reinforcing rib 2313 and the ground for tuning, significantly reduces the electromagnetic coupling between the first module 21 and the second module 22 in low-frequency bands (e.g., less than 1 GHz), that is, the electromagnetic coupling is more significantly suppressed. Therefore, the corresponding resonant network can be selected based on the frequency band in which the electromagnetic coupling needs to be suppressed.

[0093] In summary, Figure 20 This is a schematic diagram of another electromagnetic shielding structure provided in an embodiment of the present application. Figure 2 On the basis of the above, the electromagnetic shielding structure 23 further includes at least one tuning network 26, and the reinforcing ribs 2313 are grounded through the tuning network 26. For a more complex electromagnetic shielding structure 23, such as one including more cavities to accommodate more modules, more tuning networks 26 can be included, and multiple positions of the shielding frame can be grounded through multiple tuning networks 26 to enhance the effect of suppressing electromagnetic coupling between the first module 21 and the second module 22.

[0094] The tuning network 26 may include capacitors, inductors, capacitors and inductors in series, capacitors and inductors in parallel, etc. Figure 16-Figure 19 The description of different forms of the tuning network 26 is omitted here.

[0095] Any location on the reinforcing rib 2313 can be grounded via the tuning network 26. For example, when there are multiple tuning networks 26, locations on the reinforcing rib 2313 spaced at least a predetermined distance apart can be grounded via a tuning network 26 to enhance the effect of suppressing electromagnetic coupling between the first module 21 and the second module 22. The locations on the reinforcing rib 2313 connected to the tuning network 26 can be equally spaced or unequally spaced.

[0096] For another example, the location on the reinforcing rib 2313 where the electromagnetic simulated electric field is strongest can be grounded via the tuning network 26 to reduce the cost of the tuning network 26, thereby balancing cost and the effectiveness of suppressing electromagnetic coupling. The location on the reinforcing rib 2313 where the electromagnetic simulated electric field is strongest can also be more than one, for example, N locations on the reinforcing rib 2313 where the electromagnetic simulated electric field is strongest (i.e., the TOP N locations). The prior art provides all-around electromagnetic isolation between the electromagnetic interference source and the interfered object, which requires significant space and material costs. Tuning the locations on the reinforcing rib 2313 where the electromagnetic simulated electric field is strongest (i.e., electromagnetically sensitive locations) while ignoring other electromagnetically insensitive locations can reduce space and material costs.

[0097] For example, Figure 21 A schematic diagram of the electric field distribution and magnetic field distribution when different positions of a reinforcement rib are grounded through a resonant network provided in an embodiment of the present application. The darker the color, the stronger the electric field strength or magnetic field strength. The reinforcement rib is equivalent to a magnetic dipole along the x-axis direction, so the coupling degree with the magnetic field in the x-axis direction is the largest. After electromagnetic simulation, the electric field at position 1 of the reinforcement rib is the strongest. When the reinforcement rib is grounded through a tuning network at position 1, the electromagnetic coupling suppression is most obvious. Finally, it is possible to choose to ground the reinforcement rib through a tuning network at position 1.

[0098] Figure 22 A schematic diagram showing the S parameters between the first module and different locations on the rib after the rib is grounded via a resonant network, according to an embodiment of the present application. After the rib 2313 is grounded via the tuning network 26, the S parameter (S31) between the first module 21 and position g on the rib 2313 is measured, as well as the S parameter (S41) between the first module 21 and position h on the rib 2313. Figure 23 The embodiment of the present application provides a first module and a position g on the reinforcing rib (see Figure 22 ) is a schematic diagram of the S parameters between Figure 24 The embodiment of the present application provides a first module and a position h on the reinforcing rib (see Figure 22 ) between the S parameters. Figure 23 and Figure 24 It can be seen that compared with the case where the tuning network 26 is a 0.1pF capacitor, a 2pF capacitor, or the reinforcing rib 2313 is grounded, or there is no shielding frame, when the tuning network 26 is a 18pF capacitor, at a frequency of around 1.5GHz, the first module 21 and the position g on the reinforcing rib 2313 (see FIG. Figure 22 ) between the S parameter S31, and the position h between the first module 21 and the reinforcing rib 2313 (see Figure 22) are both at extremely low points, and the electromagnetic coupling between the first module 21 and the reinforcing rib 2313 is significantly reduced, thereby significantly suppressing the electromagnetic coupling between the first module 21 and the second module 22 through the reinforcing rib 2313, thereby improving the isolation between the first module 21 and the second module 22.

[0099] Figure 25 A schematic diagram of a shielding cover made of a flexible conductive material provided in an embodiment of the present application. If the shielding cover 232 is made of a flexible conductive material such as copper foil or conductive cloth, the above-mentioned tuning network can also be used to suppress the electromagnetic coupling between the first module 21 and the second module 22 within the electromagnetic shielding structure 23. Because flexible conductive materials are relatively soft, the main differences from rigid metals include: First, the flexible conductive material can be bonded to the reinforcing ribs using conductive or non-conductive adhesive, thereby achieving local insulation. Experiments have shown that the insulation between the flexible conductive material and the reinforcing ribs has a relatively small effect on the electromagnetic coupling between the first module and the second module, but significantly suppresses the electromagnetic coupling between the first module 21 and the second module 22 in specific frequency bands. Second, the flexible conductive material can deform due to the influence of temperature and internal filling materials (such as thermal conductive gel), which to a certain extent affects the suppression effect.

[0100] Figure 26 The embodiment of the present application provides a method in which when the flexible conductive material is insulated from the reinforcing rib, the first module is insulated from the reinforcing rib at position g (see Figure 22 ) is a schematic diagram of the S parameters between . Figure 27 The embodiment of the present application provides a method in which when the flexible conductive material is short-circuited with the reinforcing rib, the first module and the position g on the reinforcing rib (see Figure 22 ) is a schematic diagram of the S parameters between . Figure 28 The embodiment of the present application provides a method in which when the flexible conductive material is insulated from the vertical portion of the reinforcing rib and short-circuited with the other portions of the reinforcing rib, the first module is connected to the position g on the reinforcing rib (see Figure 22 ) is a schematic diagram of the S parameters between . Figure 29 The embodiment of the present application provides a method in which the flexible conductive material is insulated from the horizontal portion of the reinforcing rib and short-circuited with the other portions of the reinforcing rib, the first module and the position g on the reinforcing rib (see Figure 22 ) is a schematic diagram of the S parameters between .

[0101] By comparison Figure 26 and Figure 27 It can be seen that for the connection modes of the reinforcement ribs being connected to the ground through 0.1pF capacitors, 2pF capacitors, 5pF capacitors, 18pF capacitors, 33pF capacitors or not connected to capacitors, under the same connection mode, the first module 21 and position g (see Figure 22) keep the same trend of the S parameter S31 between them. Whether the reinforcing ribs are insulated from the copper foil has little effect on the isolation between the first module 21 and the second module 22. Figure 28 and Figure 29 It can be seen that for the connection modes of the reinforcement ribs through 0.1pF capacitors, 2pF capacitors, 5pF capacitors, 18pF capacitors, and 33pF capacitors to ground, under the same connection mode, the first module 21 and position g (see Figure 22 ) maintains the same trend of the S parameter S31 between the first module 21 and the second module 22. The flexible conductive material is insulated from different positions of the reinforcing ribs, which has little effect on the isolation between the first module 21 and the second module 22.

[0102] The electromagnetic shielding structure and electronic device provided in the embodiments of the present application connect a tuning network between the reinforcing ribs of the electromagnetic shielding structure and the ground, thereby changing the resonant state of the electromagnetic shielding structure (the resonant frequency remains unchanged, and the S parameter of the resonant frequency becomes smaller), suppressing the electromagnetic coupling between the first module and the second module and the reinforcing ribs, thereby suppressing the electromagnetic coupling between the first module and the second module, and reducing the electromagnetic coupling degree between the modules in the electromagnetic shielding structure.

[0103] Furthermore, existing technologies for achieving board-level anti-interference protection often employ discrete shielding, electrical connection materials (conductive foam, absorbing materials, copper foil), and other methods, and may even require architectural adjustments (such as additional shielding and grounding points), significantly impacting structure, space, and cost. The electromagnetic shielding structure and electronic device provided in the embodiments of this application achieve low-cost board-level anti-interference protection within a limited space, thus avoiding the aforementioned issues.

[0104] The modules described as separate components may or may not be physically separate, and the components shown as modules may or may not be physical modules, that is, they may be located on a single device or distributed across multiple devices. Some or all of the modules may be selected to achieve the purpose of this embodiment based on actual needs.

[0105] In addition, the functional modules in the various embodiments of the present application may be integrated into one device, or each module may exist physically separately, or two or more modules may be integrated into one device.

[0106] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An electromagnetic shielding structure, characterized in that: include: A shielding frame, a shielding cover and at least one tuning network, the shielding cover is buckled with the shielding frame, the shielding frame includes a first cavity and a second cavity, the first cavity and the second cavity are separated by reinforcing ribs, the first cavity is used to accommodate a first module, and the second cavity is used to accommodate a second module; the first module is an electromagnetic interference source, and the second module is a disturbed body. On the reinforcing rib between the first cavity and the second cavity, the position with the strongest electric field of the electromagnetic simulation is grounded through the tuning network, which is used to suppress the electromagnetic coupling between the first module and the second module.

2. The electromagnetic shielding structure according to claim 1, wherein: Positions on the reinforcing ribs that are spaced at least a predetermined distance apart are grounded through the tuning network.

3. The electromagnetic shielding structure according to claim 1 or 2, characterized in that: The tuning network includes at least one of the following: a capacitor, an inductor, a capacitor and an inductor connected in parallel, and a capacitor and an inductor connected in series.

4. The electromagnetic shielding structure according to claim 3, wherein: When the tuning network includes a capacitor, or a capacitor and an inductor connected in parallel, the tuning network is used to suppress electromagnetic coupling between the first module and the second module that is greater than 1 GHz.

5. The electromagnetic shielding structure according to claim 3, wherein: When the tuning network includes an inductor, or a capacitor and an inductor connected in series, the tuning network is used to suppress electromagnetic coupling between the first module and the second module at a frequency less than 1 GHz.

6. The electromagnetic shielding structure according to claim 3, characterized in that: The capacitance is greater than or equal to 2 pF.

7. The electromagnetic shielding structure according to claim 3, characterized in that: The inductance is greater than or equal to 8.2 nH.

8. An electronic device, characterized in that: It comprises a first module, a second module and the electromagnetic shielding structure according to any one of claims 1 to 7, wherein the first cavity of the electromagnetic shielding structure is used to accommodate the first module, and the second cavity of the electromagnetic shielding structure is used to accommodate the second module.

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