This patent application claims the benefit and priority of Chinese Patent Application No. 201910277693.1, filed on Apr. 8, 2019, the disclosure of which is incorporated by reference herein in its entirety as part of the present application.
The present disclosure relates to an apparatus for reducing interference in an antenna from an electromagnetic wave, which belongs to the field of radio anti-interference.
Currently, interference is reduced on condition that frequencies are different. For co-frequency electromagnetic waves, it is difficult to find anti-interference measures for an antenna. Nearly all technologies can hardly be used for resolving co-frequency interference.
Currently, frequency bands of most wireless WiFi signals are 2.4 GHz. The frequency band is often interfered by another router due to the co-frequency or frequency adjacency, causing slow Internet access speed and frequent “frame freezing” for mobile phones with WiFi functions. Although the 2.4 GHz frequency band is divided into approximately 13 channels, an increasing number of families are using WiFi nowadays, resulting in insufficient channels and frequent mutual interference. As too many adjacent users use the router, it is increasingly difficult to reduce frequency interference by arranging different channels. Although the frequency bands of WiFi signals may include 5 GHz, few devices are supported, and signal penetration is poor.
In consideration that electromagnetic waves are characterized by diffraction (diffraction) when transmitted, compared with those during linear transmission, the electromagnetic waves during diffraction attenuate more severely, and electromagnetic waves from different sources in space have different signal strength and transmission directions. In the present disclosure, the following technical solution is used: A method for blocking an electromagnetic wave signal port is used. A WiFi antenna or the entire router is enclosed by using an electromagnetic wave blocking material (such as an aluminum metal mesh) to form an enclosure surrounding the WiFi antenna. The enclosure is provided with one or more electromagnetic wave signal ports (a size of the opening can be selected based on a wavelength of an electromagnetic wave), to form an electromagnetic wave selection enclosure (wave selection enclosure), and the enclosure can perform selection on electromagnetic waves with different strength or in different directions or from different sources. When the wavelength satisfies a requirement for entering the signal port, an electromagnetic wave having a signal with sufficient strength, or a signal in an appropriate direction with insufficient strength, or a signal in an inappropriate direction with sufficient strength (that is, two factors of the strength and the direction jointly satisfy requirements) is allowed to enter the enclosure and communicate with the antenna, reducing or eliminating mainly interference caused by another co-frequency electromagnetic wave outside the enclosure for the antenna in the enclosure. The appropriate direction refers to a direction in which it is easier to enter the signal opening to reach the antenna, such as an incident direction closer to a straight line for entering the signal opening (the smaller the angle of diffraction is, the easier the antenna will be reached, and the smaller the attenuation of the required diffraction will be), or through the reflection of the signal, it is easier to reflect to the incident direction of the antenna in the enclosure. The direction adequacy also depends on the wavelength. The longer the wavelength is, the lower the requirements for the direction will be. In addition, the direction adequacy also depends on the strength of the electromagnetic wave. A remaining value after the attenuation of the diffraction is not excessively small only if the strength is sufficient, and as a result, the requirement for the direction is reduced. In brief, the main interference filtered out in the solution is interference from co-frequency electromagnetic waves with insufficient strength in an inappropriate direction (a required diffraction angle is large, or a reflection angle is inadequate). This is because these electromagnetic waves cannot enter the electromagnetic wave selection enclosure, or reaches or acts on the antenna.
Regarding the size of the signal port, it is necessary to ensure that a signal with a frequency or a wavelength used by the antenna in the enclosure can enter and exit from the signal port and reach the antenna in the enclosure. Generally, the size of the signal port needs to be greater than a quarter of the wavelength of the electromagnetic wave used by the antenna. However, this is not an absolute requirement because electromagnetic waves can reach a specific distance and depth through a signal port with a smaller size. The smaller the size of the signal port is, the smaller the distance and depth from the signal port reached by the electromagnetic wave will be. If the antenna in the enclosure is very close to the signal port, this is equivalent to a case that electromagnetic waves of the wavelength can enter the signal port. Therefore, regarding the problem, Claims specify a requirement that the wavelength satisfies a requirement for entering the signal port (which depends on the size of the signal port and a distance between the antenna in the enclosure and the signal port).
The larger the solid angle of enclosing the internal antenna by the electromagnetic wave selection enclosure (wave selection enclosure) mentioned in the present disclosure is, the less the interference will be (however, this is also likely to block transmission of useful signals, but this is not severe). For a purpose of quantification, the solid angle of enclosing the internal antenna by the electromagnetic wave selection enclosure (wave selection enclosure) should be greater than 2π (it is the pi), or greater than 50% of the solid angle of the sphere.
Further, to help miniaturize the device in the present disclosure, on a plane perpendicular to the signal port, only one dimension of the signal port is greater than a quarter of a wavelength of the electromagnetic wave (the electromagnetic wave of the communications antenna in the enclosure), and the other dimensions are less than a quarter of the wavelength of the electromagnetic wave. As for only one dimension, a direction that forms an angle less than 80 degrees with the dimension or a direction that is not perpendicular to the dimension is acceptable. When satisfying the requirement for the only one dimension, the electromagnetic waves can pass through the signal port.
Further, the electromagnetic wave blocking material used is an electric conductor and/or a magnetic conductor, and the material may be mesh-shaped, such as a metal layer or a metal mesh, such as an aluminum mesh or a copper mesh.
Further, the device is intended to reduce or eliminate co-frequency interference or adjacent frequency interference, such as co-frequency or adjacent frequency interference caused for the WiFi router.
Further, because an interference signal can be received only when signals are being received, the wave selection enclosure can only cover a signal receiving antenna, and a signal transmission antenna is provided outside the enclosure. In this way, the wave selection enclosure does not affect signal transmission by the antenna; or a number of signal receiving antennas in the wave selection enclosure is greater than a number of signal emitting antennas.
Further, to further filter out a weak interference signal entering from the signal port and reduce disturbance caused by a reflected signal of the electromagnetic wave, an electromagnetic wave absorption technology can be used. The wave absorption technology (including a wave absorption structure and/or a wave absorption material or a grounding technology, such as a ferrite wave-absorbing material) is used for a part or all of the electromagnetic wave selection enclosure (wave selection enclosure), or is used inside and/or outside the enclosure. For example, the wave absorption material or technology is used for the signal port. The wave absorption technology or the wave absorption material mentioned in the present disclosure includes, but is not limited to, a known technology or material, for example, known technologies of a non-smooth metal surface or a metal surface with wedges or barbs, or the ferrite wave-absorbing material. In addition, in the present disclosure, the electromagnetic wave selection enclosure (wave selection enclosure) can alternatively be grounded to absorb the electromagnetic waves.
Further, a longer electromagnetic wave signal port can be provided, and a flaring opening with diameters expending from the inside to the outside or a narrowing opening with diameters shrinking from the inside to the outside may be provided. This is more conducive to a gradual change of a waveform of the electromagnetic wave signal without confusion, making the interference signal less likely to pass.
Further, the antenna in the enclosure may be a WiFi signal antenna (such as a WiFi antenna of a router), a 4G or 5G signal antenna of a mobile phone (or an antenna of a later generation, such as 6G or 7G), a WiFi antenna of the mobile phone, another antenna of device with a WiFi function, or an antenna of a communications device with Bluetooth.
Further, because signals facing a direction of the electromagnetic wave signal port of the electromagnetic wave selection enclosure are better and more adequate, the electromagnetic wave selection enclosure (wave selection enclosure) can be directly or indirectly installed on the rotating shaft to facilitate direction adjustment. The rotating shaft can be driven by a motor to rotate, and a control circuit controls the motor based on a set program to further control a rotating direction of the wave selection enclosure, thereby controlling a direction of the electromagnetic wave signal port of the wave selection enclosure. For example, a control circuit of the WiFi router (such as a central processing unit (CPU)) controls the motor based on the set program, to further control a rotation direction of the wave selection enclosure, thereby better receiving the useful signal and filtering out the interference signal.
Further, due to some reflection effects of the inner wall of the enclosure on the electromagnetic waves (including a case in which the wave absorption technology or the wave absorption material is used for a part), a signal at the signal port of the wave selection enclosure has strong strength, which can be used to enhance signal penetration in a direction of the signal port or increase a transmission distance in the direction of the signal port, for example, can be used for 5G (or 4G, or a later generation such as 6G or 7G) signal directional transmission of a mobile phone.
Further, in the present disclosure, a turning structure may also be used, so that an electromagnetic wave signal needs to pass through one turning structure (more turning structures) to reach the antenna in the enclosure after passing through the electromagnetic wave signal port of the wave selection enclosure, thereby reducing more interference by weak signals.
The beneficial effect of the present disclosure is that a space utilization rate of a radio frequency spectrum can be increased and even multiplied, and the interference caused to the WiFi router due to the co-frequency or frequency adjacency can be reduced with low costs, ensuring that the Internet access speed of the mobile phone or the computer through WiFi are more stable and faster and greatly reducing the situations of slow Internet access speeds and frame freezing. In the present disclosure, after an actual test, if the electromagnetic wave selection enclosure made of the aluminum mesh is used to surround the WiFi router, the Internet access speed of the mobile phone through the WiFi is obviously more stable and faster.
The following describes the present disclosure in more detail with reference to the accompanying drawings and examples.
Reference numerals are described as follows: In
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The example of the present disclosure is as follows:
The present disclosure is easy to implement in industry, and the costs are also very low.
The foregoing description only provides preferred specific implementations of the present disclosure, and the protection scope of the present disclosure is not limited thereto. Any equivalent replacement or modification made according to the technical solution and inventive concept by a person skilled in the art within a technical scope of the present disclosure shall fall within the protection scope of the present disclosure.
Number | Date | Country | Kind |
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201910277693.1 | Apr 2019 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN2020/083420 | 4/6/2020 | WO | 00 |