Low-frequency electromagnetic field shielding method and device capable of transmitting high-frequency signals

Abstract

The invention relates to a low-frequency electromagnetic field shielding method and device capable of transmitting high-frequency signals, and the method comprises the following steps: arranging a magnetic shielding cavity, and placing a target object in the magnetic shielding cavity; a through hole is formed in the magnetic shielding cavity, one end of an antenna penetrates through the through hole to be connected to the target object, and the antenna is electrically connected with a circuit of the target object and does not make contact with the magnetic shielding cavity; electroplating a good conductor layer on the outer surface of the magnetic shielding cavity; one end of the inductor is connected with the antenna, and the other end of the inductor is connected with the good conductor layer.

Description

Technical Field

[0001] The invention relates to a low-frequency electromagnetic field shielding method and device capable of transmitting high-frequency signals, belonging to the technical field of electronic communications. Background Art

[0002] In the field of wireless communications, shielding low-frequency electromagnetic fields while transmitting high-frequency signals is a scenario that often needs to be faced.

[0003] Prior art, such as Chinese invention patent publication number CN102177619A, discloses an electromagnetic filter for transmitting electrical signals to an external device in a non-contact state, and can shield low-frequency noise signals while transmitting signals.

[0004] However, the overall structure of the above solution is relatively complex, which is not conducive to promotion and application. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention proposes a low-frequency electromagnetic field shielding method and device capable of transmitting high-frequency signals.

[0006] The technical solution of the present invention is as follows:

[0007] In one aspect, the present invention provides a low-frequency electromagnetic field shielding method capable of transmitting high-frequency signals, comprising the following steps:

[0008] Providing a magnetic shielding cavity, and placing the target object in the magnetic shielding cavity;

[0009] A through hole is opened on the magnetic shielding cavity, and one end of an antenna is inserted into the through hole and connected to the target object, wherein the antenna is electrically connected to the circuit of the target object and does not contact the magnetic shielding cavity;

[0010] Electroplating a good conductor layer on the surface of the magnetic shielding cavity;

[0011] An inductor is provided, one end of the inductor is connected to the antenna, and the other end of the inductor is connected to the good conductor layer.

[0012] As a preferred implementation, the thickness of the good conductor layer is greater than a preset skin depth of the low-frequency signal.

[0013] As a preferred embodiment, the magnetic shielding cavity is provided with an openable and closable cover, and the magnetic shielding cavity is opened or closed by the cover.

[0014] As a preferred embodiment, the through hole is opened at the top center of the magnetic shielding cavity.

[0015] As a preferred implementation, the antenna is a straight conductor antenna.

[0016] On the other hand, the present invention also provides a low-frequency electromagnetic field shielding device capable of transmitting high-frequency signals, comprising:

[0017] The magnetic shielding cavity is made of magnetic shielding material, and the target object is placed inside the cavity. A through hole is provided in the magnetic shielding cavity.

[0018] An antenna, one end of which is inserted into the through hole and connected to the target object, the antenna being electrically connected to the circuit of the target object and not in contact with the magnetic shielding cavity;

[0019] A good conductor layer is provided on the surface of the magnetic shielding cavity by electroplating;

[0020] An inductor, one end of which is connected to the antenna, and the other end of which is connected to the good conductor layer.

[0021] As a preferred implementation, the thickness of the good conductor layer is greater than a preset skin depth of the low-frequency signal.

[0022] As a preferred embodiment, the magnetic shielding cavity is provided with an openable and closable cover, and the magnetic shielding cavity is opened or closed by the cover.

[0023] As a preferred embodiment, the through hole is opened at the top center of the magnetic shielding cavity.

[0024] As a preferred implementation, the antenna is a straight conductor antenna.

[0025] Additional aspects and advantages of the present invention will be set forth in the following description, and some of them will be apparent from the description, or may be understood by practicing the present invention. In addition, the various aspects and advantages of the present invention may be realized and obtained by the method steps and combinations particularly pointed out in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the method flow of Embodiment 1 of the present invention;

[0027] Figure 2 This is a schematic diagram of the overall structure of the device according to the second embodiment of the present invention;

[0028] Figure 3 is a schematic structural diagram of a good conductor layer in an embodiment of the present invention;

[0029] Figure 4 Schematic diagram of the structure of the magnetic shielding cavity in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] It should be understood that the step numbers used in this document are only for convenience of description and are not intended to limit the order in which the steps are executed.

[0032] It should be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0033] The terms “include” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0034] The term "and / or" means and includes any and all possible combinations of one or more of the associated listed items.

[0035] In order to help those skilled in the art to more quickly understand the technical solutions of the embodiments, some terms are explained below.

[0036] Electromagnetic shielding is a technology or measure used to reduce or block the adverse effects of electromagnetic fields on specific areas or equipment. It is mainly achieved by setting up a shield on the propagation path of electromagnetic waves, and using the shield's reflection, absorption and guidance of electromagnetic waves to limit electromagnetic waves to a certain area, or to prevent a certain area from being affected by external electric and magnetic lines of force.

[0037] There are many ways to achieve electromagnetic shielding, including the use of metal shields, conductive coatings, electromagnetic shielding materials, etc. Shielding materials usually have good electrical conductivity and magnetic permeability, and can effectively absorb and reflect electromagnetic waves, thereby reducing the penetration ability of electromagnetic waves.

[0038] Electromagnetic shielding cavity is usually a cavity made of metal, which is used to control the propagation of electromagnetic waves. The principle is to use the reflection and absorption of electromagnetic waves by the shielding body to reduce the propagation of electromagnetic waves from one area to another. Reflection loss is when the electromagnetic wave reaches the surface of the shielding cavity, due to the discontinuity of the impedance of the air-metal interface, part of the incident electromagnetic wave will be reflected on the surface of the cavity. The reflection effect can effectively prevent the electromagnetic wave from entering the shielding cavity. Absorption loss means that part of the electromagnetic wave energy entering the shielding cavity will be absorbed by the shielding body. The degree of absorption loss depends on the conductivity and permeability of the shielding material.

[0039] Embodiment 1:

[0040] See also Figure 1 This embodiment provides a low-frequency electromagnetic field shielding method capable of transmitting high-frequency signals, which can shield the low-frequency electromagnetic field in a complex low-frequency electromagnetic field environment, and then realize the transmission of high-frequency signals by designing a transmission structure. The method includes the following steps:

[0041] S100, setting a magnetic shielding cavity, placing a target object in the magnetic shielding cavity; the magnetic shielding cavity uses electromagnetic shielding materials, such as stainless steel. The target object can be a circuit module, an electronic device, or other object that can transmit signals.

[0042] S200, a through hole is opened on the magnetic shielding cavity, and one end of an antenna is inserted into the through hole and connected to the target object, and the antenna is connected to the circuit of the target object and does not contact the magnetic shielding cavity. If the antenna contacts the magnetic shielding cavity, the entire magnetic shielding cavity becomes a conductor connected to the internal circuit and cannot play the role of shielding only low-frequency signals. Therefore, the antenna cannot contact the magnetic shielding cavity.

[0043] S300, electroplating a good conductor layer on the surface of the magnetic shielding cavity; the good conductor layer is electroplated with a good conductor, such as tin, copper, etc.

[0044] S400, set an inductor, connect one end of the inductor to the antenna, and connect the other end to the good conductor layer. The function of the inductor is to filter out excess low-frequency content and ensure high-frequency transmission.

[0045] Based on the method of this embodiment, the target object can communicate wirelessly with the external device through the antenna, and during the communication process, high-frequency signals can be transmitted while filtering low-frequency signals.

[0046] As a preferred implementation of this embodiment, the thickness of the good conductor layer is greater than the preset skin depth of the low-frequency signal. The skin depth is:

[0047]

[0048] Wherein, δ is the skin depth (m), ω is the angular frequency; ω=2πf (rad / s), f is the magnetic field frequency; μ is the magnetic permeability (H / m); ρ is the resistivity (Ω·m); σ is the electrical conductivity (S / m).

[0049] As a preferred embodiment, the magnetic shielding cavity is provided with an openable and closable cover, the magnetic shielding cavity is opened or closed by the cover, the target object is placed in by opening the cover, and the cover is closed after the target object is placed in.

[0050] As a preferred embodiment, the through hole is opened at the top center of the magnetic shielding cavity.

[0051] As a preferred implementation, the antenna is a linearly polarized straight conductor antenna, which is usually made of metal with good electrical conductivity, such as copper, aluminum or alloy, and can effectively transmit and radiate electromagnetic waves.

[0052] Embodiment 2:

[0053] See also Figure 2 , this embodiment provides a low-frequency electromagnetic field shielding device capable of transmitting high-frequency signals, comprising:

[0054] The magnetic shielding cavity is made of magnetic shielding material, and the target object is placed inside it. A through hole is opened on the magnetic shielding cavity; the magnetic shielding cavity uses electromagnetic shielding materials, such as stainless steel. The target object can be a circuit module, an electronic device, or other object that can transmit signals.

[0055] See also Figure 3 The magnetic shielding cavity is designed as a hollow cylinder with an opening at the bottom and a small hole at the top, so that the antenna can pass through the cavity without contacting it. The size of the cylindrical cavity can be enlarged or reduced according to the specific application environment. The thicker the cavity wall, the better the performance. A cover that can be opened or closed is provided at the bottom of the magnetic shielding cavity, and the magnetic shielding cavity is opened or closed by the cover. The magnetic shielding cavity is opened or closed by the cover, and the target object is placed in by opening the cover, and the cover is closed after the target object is placed in.

[0056] Antenna, one end of the antenna is inserted into the through hole and connected to the target object. The antenna is electrically connected to the circuit of the target object and does not contact the magnetic shielding cavity; so that the high-frequency wireless signal in the circuit can be transmitted to the outside world through the antenna. The antenna uses a linearly polarized straight conductor antenna, which is usually made of metal with good conductive properties, such as copper, aluminum or alloy, and can effectively transmit and radiate electromagnetic waves.

[0057] See also Figure 4, a good conductor layer, which is set on the surface of the magnetic shielding cavity by electroplating; the good conductor layer is a conductor layer of the same size as the hollow cylindrical top cover of the magnetic shielding cavity. This layer is electroplated with a good conductor, such as tin, copper, etc., and its thickness must be greater than the skin depth of the low-frequency electromagnetic field signal. The plating layer must retain a small central hole to ensure that it is aligned with the central opening of the shielding cavity, so that the antenna can pass through the plating layer without contacting the plating layer.

[0058] Inductor, one end of the inductor is connected to the antenna, and the other end is connected to the good conductor layer. After the connection is completed, the structure can be shielded from low-frequency electromagnetic fields and can transmit high-frequency electrical signals.

[0059] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A low-frequency electromagnetic field shielding method capable of transmitting high-frequency signals, characterized in that: The following steps are involved: Providing a magnetic shielding cavity, and placing the target object in the magnetic shielding cavity; A through hole is opened on the magnetic shielding cavity, and one end of an antenna is inserted into the through hole and connected to the target object, wherein the antenna is electrically connected to the circuit of the target object and does not contact the magnetic shielding cavity; Electroplating a good conductor layer on the surface of the magnetic shielding cavity; An inductor is provided, one end of the inductor is connected to the antenna, and the other end of the inductor is connected to the good conductor layer.

2. A low-frequency electromagnetic field shielding method capable of transmitting high-frequency signals according to claim 1, characterized in that: The thickness of the good conductor layer is greater than a preset skin depth of the low-frequency signal.

3. A low-frequency electromagnetic field shielding method capable of transmitting high-frequency signals according to claim 1, characterized in that: The magnetic shielding cavity is provided with an openable and closable cover body, and the magnetic shielding cavity is opened or closed by the cover body.

4. A low-frequency electromagnetic field shielding method capable of transmitting high-frequency signals according to claim 1, characterized in that: The through hole is opened at the top center of the magnetic shielding cavity.

5. A low-frequency electromagnetic field shielding method capable of transmitting high-frequency signals according to claim 1, characterized in that: The antenna is a straight conductor antenna.

6. A low-frequency electromagnetic field shielding device capable of transmitting high-frequency signals, characterized in that: include: The magnetic shielding cavity is made of magnetic shielding material, and the target object is placed inside the cavity. A through hole is provided in the magnetic shielding cavity. An antenna, one end of which is inserted into the through hole and connected to the target object, the antenna being electrically connected to the circuit of the target object and not in contact with the magnetic shielding cavity; A good conductor layer is provided on the surface of the magnetic shielding cavity by electroplating; An inductor, one end of which is connected to the antenna, and the other end of which is connected to the good conductor layer.

7. A low-frequency electromagnetic field shielding device capable of transmitting high-frequency signals according to claim 6, characterized in that: The thickness of the good conductor layer is greater than a preset skin depth of the low-frequency signal.

8. A low-frequency electromagnetic field shielding device capable of transmitting high-frequency signals according to claim 6, characterized in that: The magnetic shielding cavity is provided with an openable and closable cover body, and the magnetic shielding cavity is opened or closed by the cover body.

9. A low-frequency electromagnetic field shielding device capable of transmitting high-frequency signals according to claim 6, characterized in that: The through hole is opened at the top center of the magnetic shielding cavity.

10. A low-frequency electromagnetic field shielding device capable of transmitting high-frequency signals according to claim 6, characterized in that: The antenna is a straight conductor antenna.

Images