CN215008586U - Frequency selection surface and electronic device - Google Patents

Abstract

The present disclosure provides a frequency selective surface and an electronic device, which belong to the technical field of microwave, and can solve the problems of poor frequency selectivity and thick thickness of the existing frequency selective surface. The frequency selective surface of the present disclosure comprises: the resonant structure comprises a dielectric substrate and a plurality of resonant structures arranged on the dielectric substrate in an array manner; each resonant structure includes: a plurality of protrusions disposed in a disconnected state; the extending directions of the plurality of projections intersect.

Description

Frequency selection surface and electronic device

Technical Field

The disclosure belongs to the technical field of microwaves, and particularly relates to a frequency selective surface and an electronic device.

Background

The Frequency Selective Surface (FSS) is a two-dimensional periodic array structure, which is essentially a spatial filter, and exhibits a significant passband or bandstop filter characteristic when interacting with electromagnetic waves. Under the trend of 5G industrial interconnection, in order to realize high-speed data transmission in factories, experts in the industry increasingly show that a 4.9GHz frequency band (namely an N79 frequency band: 4800MHz-4900MHz) is expected to become a favorable frequency band for the large-scale uplink of industrial interconnection data. However, in today's complex electromagnetic wave environment, the quality of communication between communication devices is often affected by crosstalk between electromagnetic waves of different frequency bands. Therefore, it is a hot issue to develop a band-stop frequency selection surface capable of effectively blocking the inside and outside penetration and leakage of the electromagnetic wave in this frequency band.

The current frequency selective surfaces are all broadband bandstop frequency selective surfaces, i.e. low frequency selective surface structures. Although such a structure can successfully block the transmission of the electromagnetic wave in the target frequency band, the structure can still block the electromagnetic wave in other frequency bands outside the target frequency band. Therefore, the frequency selectivity of this type of structure is not perfect. In order to improve the frequency selectivity, a single-layer structure multi-layer cascade is generally used, however, the multi-layer cascade method increases the thickness of the structure and adds weight to the whole structure in an intangible way. Moreover, the existing frequency selection surface structures are all non-transparent structures, which are not beneficial to being in common with other structures and influence the aesthetic appearance of the structures.

SUMMERY OF THE UTILITY MODEL

The present disclosure is directed to at least one of the problems of the prior art, and provides a frequency selective surface and an electronic device.

In a first aspect, an embodiment of the present disclosure provides a frequency selective surface, including: the resonant structure comprises a dielectric substrate and a plurality of resonant structures arranged on the dielectric substrate in an array manner;

each of the resonant structures includes: a plurality of protrusions disposed in a disconnected state; the extending directions of the plurality of protruding portions intersect.

Optionally, the protrusion comprises: the U-shaped part, the first connecting part and the second connecting part;

one end of the U-shaped part is connected with the first connecting part, and the other end of the U-shaped part is connected with the second connecting part.

Optionally, the U-shaped portion comprises: a third connection portion, a fourth connection portion, and a fifth connection portion;

one end of the third connecting part and one end of the fourth connecting part are respectively connected with two ends of the fifth connecting part, and the third connecting part and the fourth connecting part are oppositely arranged,

the other end of the third connecting portion is connected with the first connecting portion, and the other end of the fourth connecting portion is connected with the second connecting portion.

Optionally, in the same resonant structure, the side edges of the adjacent fifth connecting parts are at least partially arranged oppositely.

Optionally, in the same resonant structure, the fifth connecting portions surround to form a hollow opening.

Optionally, the first connecting portion, the second connecting portion, the third connecting portion, the fourth connecting portion, and the fifth connecting portion are integrally formed.

Optionally, each of the resonant structures comprises: four of the projections; wherein the content of the first and second substances,

two opposite protruding parts are arranged in axial symmetry.

Optionally, the dielectric substrate comprises: a transparent dielectric substrate.

Optionally, the protrusion comprises: and (3) a metal patch.

Optionally, the metal patch includes: a plurality of metal grid lines.

In a second aspect, embodiments of the present disclosure provide an electronic device comprising a frequency selective surface as provided above.

Drawings

FIG. 1 is a schematic diagram of an exemplary frequency selective surface structure;

fig. 2 is a schematic structural diagram of a frequency selective surface according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of a resonant structure in the frequency selective surface of FIG. 2;

FIG. 4 is a schematic diagram of a resonant structure in an exemplary frequency selective surface;

FIG. 5 is a schematic illustration of the insertion loss of the frequency selective surface shown in FIG. 4;

FIG. 6 is a schematic diagram of a resonant structure in another exemplary frequency selective surface;

FIG. 7 is a schematic illustration of the insertion loss of the frequency selective surface shown in FIG. 6;

fig. 8 is a schematic illustration of the insertion loss of a frequency selective surface shown in fig. 2.

Detailed Description

For a better understanding of the technical aspects of the present disclosure, reference is made to the following detailed description taken in conjunction with the accompanying drawings.

Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The use of "first," "second," and similar terms in this disclosure is not intended to indicate any order, quantity, or importance, but rather is used to distinguish one element from another. Also, the use of the terms "a," "an," or "the" and similar referents do not denote a limitation of quantity, but rather denote the presence of at least one. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

Fig. 1 is a schematic diagram of an exemplary frequency selective surface, as shown in fig. 1, comprising: a dielectric substrate 101, and a plurality of resonant structures 102 arranged in an array on the dielectric substrate 101. The dielectric substrate 101 is generally made of a printed circuit board, and is made of a hard non-transparent material, and can effectively support the resonant structure 102 formed on the dielectric substrate, the resonant structure 102 can be made of a metal patch, a hollow opening can be formed in the metal patch to block electromagnetic waves of a corresponding target frequency band, and the electromagnetic waves of other frequency bands are transmitted, so that interference of signals carried by the electromagnetic waves of different frequency bands is avoided, and further, communication quality can be improved. However, the current frequency selective surfaces are all broadband bandstop frequency selective surfaces, i.e. low frequency selective surface structures. Although such a structure can successfully block the transmission of the electromagnetic wave in the target frequency band, the structure can still block the electromagnetic wave in other frequency bands outside the target frequency band. Therefore, the frequency selectivity of this type of structure is not perfect. In order to improve the frequency selectivity, a single-layer structure multi-layer cascade is generally used, however, the multi-layer cascade method increases the thickness of the structure and adds weight to the whole structure in an intangible way. Moreover, the existing frequency selection surface structures are all non-transparent structures, which are not beneficial to being in common with other structures and influence the aesthetic appearance of the structures.

In order to solve at least one of the above technical problems of the frequency selective surface in the related art, embodiments of the present disclosure provide a frequency selective surface and an electronic device, which will be described in further detail with reference to the accompanying drawings and detailed description.

In a first aspect, an embodiment of the present disclosure provides a frequency selective surface, and fig. 2 is a schematic structural diagram of the frequency selective surface provided in the embodiment of the present disclosure, as shown in fig. 2, the frequency selective surface includes: the resonator comprises a dielectric substrate 101 and a plurality of resonant structures 102 arranged on the dielectric substrate 101 in an array manner; each resonant structure 102 includes: a plurality of protrusions 103 provided in a disconnected state; the extending directions of the plurality of projections 103 intersect.

The dielectric substrate 101 may be made of a square plate material, and may effectively support the resonant structure 102 printed thereon, so as to ensure polarization stability of the resonant structure 102, and the specific size of the dielectric substrate 101 may be set according to the size of the resonant structure 102, and is not limited herein. It is understood that the shape of the dielectric substrate 101 may also be other shapes such as triangle, polygon, etc., which are not listed here. The dielectric constant of the material can be 2.0 to 3.0, and the material with the appropriate relative dielectric constant can be selected according to actual needs.

The resonant structure 102 may be composed of a plurality of protrusions 103 with a break, and the extending directions of the protrusions 103 intersect, wherein the protrusions 103 may be made of a metal material or a non-metal material with good conductive performance, and can block the electromagnetic wave of the target frequency band and transmit the electromagnetic wave except the target frequency band, so as to ensure good communication quality. The frequency band of the electromagnetic wave blocked by the entire resonance structure 102 can be adjusted by adjusting the pitch between the inner structures of the protruding portions 103 and the pitch between the adjacent protruding portions 103.

In the embodiment of the present disclosure, an electromagnetic wave in a 4.9GHz band (i.e., N79 band: 4800MHz-4900MHz) is used as a target band, and tests show that the frequency selective surface provided in the embodiment of the present disclosure can have good frequency selectivity for the electromagnetic wave in the target band, and can effectively block the electromagnetic wave in the target band, so that steep insertion loss curves on two sides of the target band can be realized only by using one layer of resonant structure 102, and insertion loss characteristics of a common low-frequency band (700MHz-3500MHz) can be as low as less than 1dB, and thus, the frequency selectivity can be improved without using a multilayer cascade method, so that the frequency selective surface can be ensured to have good frequency selectivity, the thickness of the frequency selective surface can be reduced, and further, the product is light and thin, and the user experience can be improved.

Fig. 3 is a schematic diagram of a resonant structure in a frequency selective surface as shown in fig. 2, wherein each protrusion 103 of the resonant structure 102 comprises: a U-shaped portion, a first connection portion 1031, and a second connection portion 1032; one end of the U-shaped portion is connected to the first connection portion 1031, and the other end is connected to the second connection portion 1032.

In the embodiment of the present disclosure, the same resonant structure 102 may be provided with a plurality of protruding portions 103, that is, a plurality of U-shaped portions, bottoms of the respective U-shaped portions are close to each other, openings of the respective U-shaped portions are far away from each other, and the protruding portions 103 extend in a direction away from the openings of the U-shaped portions. The U-shaped portion may be formed in an "Ω" shape as shown in fig. 3 by connecting the first connection portion 1031 and the second connection portion 1032 at both ends thereof, respectively. In order to facilitate understanding of the frequency selective characteristics of the frequency selective surface provided by the embodiments of the present disclosure, the frequency selective surface provided by the embodiments of the present disclosure will be described below by comparing the frequency selective surfaces of the other two structures in the related art. Fig. 4 is a schematic diagram of a resonant structure in an exemplary frequency selective surface, which is shown in fig. 4 as having a ring shape. Fig. 5 is a schematic diagram showing the insertion loss of the frequency selective surface shown in fig. 4, and as shown in fig. 5, the frequency selective surface of the ring resonator structure has a good broadband selectivity. The frequency selection surface of the annular resonance structure meets the insertion loss characteristic of 4.14GHz-5.75GHz (bandwidth: 1.61GHz) under the standard of-10 dB, and the insertion loss under the frequency band of 3.5GHz is only-5.08 dB. Therefore, although the frequency selective surface of the ring-shaped resonant structure can easily block the target frequency band (4800MHz-4960MHz), it cannot realize low loss in the common low frequency band (700MHz-3500 MHz). Fig. 6 is a schematic diagram of a resonant structure in another exemplary frequency selective surface, which is shown in fig. 6 as having a "meter" shape. FIG. 7 is a schematic diagram of the insertion loss of the frequency selective surface shown in FIG. 6, and the "meter" shaped frequency selective surface can satisfy the-10 dB insertion loss bandwidth of 4.49GHz-5.32GHz (bandwidth: 830MHz) as shown in FIG. 7. Although the frequency selectivity is improved compared with that of a ring-shaped frequency selective surface, the insertion loss characteristic at the frequency point of 3.5GHz cannot be effectively reduced. As shown in FIG. 7, the "M" shaped frequency selective surface can only realize the insertion loss characteristic of-2.3 dB at the frequency point of 3.5GHz, and the insertion loss at the frequency point of 3.5GHz cannot be reduced to less than 1dB by the "M" shaped frequency selective surface. Fig. 8 is a schematic diagram of the insertion loss of the frequency selective surface shown in fig. 2, and as shown in fig. 8, the frequency selective surface provided in the embodiment of the present disclosure can satisfy the-10 dB insertion loss characteristic of 4.79GHz-4.96GHz (bandwidth: 170MHz), and can effectively reduce the insertion loss in the 3.5GHz band to be less than 1 dB. Currently, the frequency selective surface provided by the embodiment of the disclosure can realize an insertion loss characteristic of-0.74 dB in a frequency band of 3.5 GHz. It can be seen that the frequency selective surface provided by the embodiment of the present disclosure has very excellent frequency selective characteristics, and ensures efficient transmission in a common low frequency range (700MHz-3500MHz), so that it is not necessary to adopt a multi-layer cascade connection manner to improve the frequency selectivity, and thus the thickness of the frequency selective surface can be reduced while ensuring that the frequency selective surface has good frequency selectivity, thereby being beneficial to thinning of products and improving user experience.

In some embodiments, the U-shaped portion comprises: a third connection portion 1033, a fourth connection portion 1034, and a fifth connection portion 1035; one end of the third connection portion 1033 and one end of the fourth connection portion 1034 are respectively connected to two ends of the fifth connection portion 1035, the third connection portion 1033 and the fourth connection portion 1034 are oppositely disposed, the other end of the third connection portion 1033 is connected to the first connection portion 1031, and the other end of the fourth connection portion 1034 is connected to the second connection portion 1032.

The third connection portion 1033 and the fourth connection portion 1034 are disposed opposite to each other in the U-shaped portion, and specifically, the third connection portion 1033 and the fourth connection portion 1034 may be parallel to each other and connected to each other by the fifth connection portion 1035. It should be noted that, in order to ensure excellent frequency selection characteristics of the entire frequency selection surface, the ends of the first connection portion 1031, the second connection portion 1032, the third connection portion 1033, the fourth connection portion 1034, and the fifth connection portion 1035 may take a chamfered form, that is, each end may have a non-right-angled shape. In practical application, the frequency band of the electromagnetic wave blocked by the whole frequency selection surface can be adjusted by adjusting the distance between the third connection portion 1033 and the fourth connection portion 1034, so that the electromagnetic wave of a target frequency band (4800MHz-4960MHz) and the high-efficiency transmission of a common low frequency band (700MHz-3500MHz) are realized, and thus, the frequency selectivity of the frequency selection surface can be improved without adopting a multilayer cascade mode, the thickness of the frequency selection surface can be reduced while the frequency selection surface is ensured to have good frequency selectivity, and the product is light and thin, so that the use experience of a user is improved. It is understood that, in the embodiment of the present disclosure, each protrusion 103 may be formed by five connecting portions to form an "Ω" shape, and the number of the connecting portions may be other numbers to form a greater number of "Ω" shapes, so as to improve the frequency selection characteristic of the frequency selection surface as a whole, and the specific number may be set according to actual needs, and will not be described in detail herein.

In some embodiments, the sides of the adjacent fifth connecting portions 1035 are at least partially disposed opposite to each other in the same resonant structure 102.

The side edges of the adjacent fifth connecting portions 1035 may be at least partially disposed oppositely, a certain gap may be formed therebetween, and the capacitance value of the whole resonance structure 102 may be adjusted by adjusting the size of the gap, so that the resonance bandwidth is greatly reduced to satisfy the-10 dB insertion loss characteristic of 4.79GHz-4.96GHz (bandwidth: 170MHz), and the insertion loss in the 3.5GHz band may be effectively reduced to be lower than 1dB, thereby ensuring that the frequency selection surface has good frequency selectivity.

In some embodiments, in the same resonant structure, each fifth connecting portion 1035 surrounds to form a hollow opening.

The hollow opening surrounded by the fifth connecting portions 1035 has the same function as the gap between the adjacent fifth connecting portions 1035, and the capacitance of the whole resonance structure 102 can be adjusted, so that the resonance bandwidth is greatly reduced to meet the-10 dB insertion loss characteristic of 4.79GHz-4.96GHz (bandwidth: 170MHz), the insertion loss under the 3.5GHz frequency band can be effectively reduced to be lower than 1dB, and the frequency selection surface has good frequency selectivity.

In some embodiments, the first connection portion 1031, the second connection portion 1032, the third connection portion 1033, the fourth connection portion 1034 and the fifth connection portion 1035 are an integrally molded structure.

In practical applications, the first connection portion 1031, the second connection portion 1032, the third connection portion 1033, the fourth connection portion 1034 and the fifth connection portion 1035 may be formed at one time by using a stamping process or an etching process, so that the number of manufacturing steps may be reduced, and the manufacturing cost may be saved. It is understood that each connection portion may be formed separately, and will not be described in detail herein.

In some embodiments, each resonant structure 102 includes: four projections 103; the two opposite projections 103 are arranged axisymmetrically.

Specifically, each resonant structure 102 may include four protrusions 103 arranged in a disconnected manner, and two opposite protrusions 103 are arranged in an axisymmetric manner, so that good frequency selectivity may be achieved for the electromagnetic wave in the target frequency band (4800MHz-4960MHz), the electromagnetic wave in the target frequency band (4800MHz-4960MHz) may be effectively blocked, steep insertion loss curves at two sides of the target frequency band may be achieved only by using one layer of resonant structure 102, so that the insertion loss characteristic of the common low-frequency band (700MHz-3500MHz) may be as low as below 1dB, and the frequency selectivity may not be improved by using a multilayer cascade method, so that the frequency selection surface may be guaranteed to have good frequency selectivity, and the thickness of the frequency selection surface may be reduced, which is further beneficial to thinning of a product, so as to improve user experience. It is understood that other numbers of protrusions 103 may be provided to meet the requirement of target frequencies in other frequency bands, and the principle is similar to that of the frequency selection surface, and will not be described herein again.

In some embodiments, the dielectric substrate 101 includes: a transparent dielectric substrate.

The dielectric substrate 101 may be a transparent dielectric substrate, which may be a flexible dielectric substrate or a rigid dielectric substrate, and the specific material may be a transparent plastic film or glass, so as to ensure that the entire frequency selective surface is transparent, and thus the frequency selective surface may have excellent beautifying property or concealing property. And can be attached to the surface of objects such as transparent glass, transparent plastic and the like to realize hiding property, thereby playing the effect of beautifying the environment.

In some embodiments, protrusion 103 comprises: and (3) a metal patch.

The protruding portion 103 may be made of metal patches, the width of each metal patch may be 1.5 mm to 3 mm, and a certain gap is formed between adjacent metal patches, so that light can penetrate through the gap, and the frequency selective surface has good light transmittance, so that the frequency selective surface is transparent, and thus has excellent beautifying characteristics or concealment. And can be attached to the surface of objects such as transparent glass, transparent plastic and the like to realize hiding property, thereby playing the effect of beautifying the environment. It is understood that the protrusion 103 may be made of other transparent conductive materials, which have the same principle and are not listed here.

In some embodiments, the metal patch includes a plurality of metal grid lines.

The metal patch can be made of metal grid lines, the size of the metal grid lines can be in a micron level, for example, the line width of the metal grid lines can be 2 microns to 30 microns, the thickness can be 1 micron to 10 microns, and the space between adjacent metal grid lines can be 50 microns to 200 microns. Because the size of the metal grid lines is small, the whole metal patch looks transparent, light can penetrate through, the whole frequency selection surface has good light transmittance, and therefore the whole frequency selection surface is transparent, and the frequency selection surface can have excellent beautifying characteristics or concealment. And can be attached to the surface of objects such as transparent glass, transparent plastic and the like to realize hiding property, thereby playing the effect of beautifying the environment. Corresponding to each structure in the protruding portion 103, the first connection portion 1031, the second connection portion 1032, the third connection portion 1033, the fourth connection portion 1034 and the fifth connection portion 1035 are all made of metal grid lines, the third connection portion 1033 and the fifth connection portion 1035 may be oppositely arranged and may be arranged in parallel, a hollow gap may be formed therebetween, specifically, a distance between the third connection portion 1033 and the fifth connection portion 1035 may be 50 micrometers to 200 micrometers, so that the electromagnetic wave of the target frequency band (4800MHz-4960MHz) may have good frequency selectivity, the electromagnetic wave of the target frequency band (4800MHz-4960MHz) may be effectively blocked, steep insertion loss curves at both sides of the target frequency band may be realized only by one layer of resonance structure 102, and the insertion loss characteristic of the common low frequency band (700MHz-3500MHz) may be as low as 1dB or less, the frequency selectivity can be improved without adopting a multilayer cascading mode, so that the thickness of the frequency selection surface can be reduced while the frequency selection surface is ensured to have good frequency selectivity, and further the light and thin product is facilitated, and the use experience of a user is improved.

In a second aspect, embodiments of the present disclosure provide an electronic device including a frequency selective surface as provided in any of the above embodiments. The electronic device can be any product or component with a communication function, such as a mobile phone, a tablet computer, a television, a notebook computer, a navigator and the like. The implementation principle and the technical effect of the electronic device can refer to the above discussion of the implementation principle and the technical effect of the frequency selection surface, and are not described herein again.

It is to be understood that the above embodiments are merely exemplary embodiments that are employed to illustrate the principles of the present disclosure, and that the present disclosure is not limited thereto. It will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the disclosure, and these are to be considered as the scope of the disclosure.

Claims (11)

1. A frequency selective surface, comprising: the resonant structure comprises a dielectric substrate and a plurality of resonant structures arranged on the dielectric substrate in an array manner;

each of the resonant structures includes: a plurality of protrusions disposed in a disconnected state; the extending directions of the plurality of protruding portions intersect.

2. The frequency selective surface of claim 1, wherein the protrusion comprises: the U-shaped part, the first connecting part and the second connecting part;

one end of the U-shaped part is connected with the first connecting part, and the other end of the U-shaped part is connected with the second connecting part.

3. The frequency selective surface of claim 2, wherein the U-shaped portion comprises: a third connection portion, a fourth connection portion, and a fifth connection portion;

one end of the third connecting part and one end of the fourth connecting part are respectively connected with two ends of the fifth connecting part, and the third connecting part and the fourth connecting part are oppositely arranged,

the other end of the third connecting portion is connected with the first connecting portion, and the other end of the fourth connecting portion is connected with the second connecting portion.

4. A frequency selective surface according to claim 3, wherein the sides of adjacent fifth connecting portions are at least partially oppositely disposed in the same resonant structure.

5. The frequency selective surface of claim 3, wherein a plurality of the fifth connecting portions surround to form a hollow opening in the same resonant structure.

6. The frequency selective surface of claim 3, wherein the first connection portion, the second connection portion, the third connection portion, the fourth connection portion, and the fifth connection portion are an integrally molded structure.

7. The frequency selective surface of claim 1, wherein each of the resonant structures comprises: four of the projections; wherein the content of the first and second substances,

two opposite protruding parts are arranged in axial symmetry.

8. The frequency selective surface of claim 1, wherein the dielectric substrate comprises: a transparent dielectric substrate.

9. The frequency selective surface of claim 1, wherein the protrusion comprises: and (3) a metal patch.

10. The frequency selective surface of claim 9, wherein the metal patch comprises: a plurality of metal grid lines.

11. An electronic device, characterized in that it comprises a frequency selective surface according to any one of claims 1-10.

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