WO2019210717A1

WO2019210717A1 - Band-stop filter

Info

Publication number: WO2019210717A1
Application number: PCT/CN2019/073810
Authority: WO
Inventors: 李程; 郑渚; 杨彬; 丁庆
Original assignee: 深圳市太赫兹科技创新研究院; 深圳市太赫兹科技创新研究院有限公司
Priority date: 2018-05-02
Filing date: 2019-01-30
Publication date: 2019-11-07
Also published as: CN108598633A

Abstract

The present invention relates to the field of infrared communications, and provides a band-stop filter, comprising a filter unit structure. The filter unit structure comprises a first metal layer, a first dielectric layer, and a second metal layer. The first metal layer, the first dielectric layer, and the second metal layer are sequentially stacked. The first metal layer and the second metal layer have the same structure. The metal layer, the dielectric layer, and the metal layer are sequentially stacked to form the filter unit structure, so that the wide filter band of the band-stop filter is realized, and the band-stop filter can be applied to future high-speed communications.

Description

Band stop filter

Technical field

The present invention relates to the field of infrared communication, and in particular to a band rejection filter.

Background technique

Metamaterials are artificial electromagnetic materials composed of periodically arranged subwavelength structural units. Compared with conventional natural materials, metamaterials have special electromagnetic properties such as negative refractive index and negative magnetic permeability, and these characteristics are difficult to obtain from natural materials, and therefore, through the shape and size of metamaterial structural units. And the control of the material components, the researchers can achieve the tuning and control of electromagnetic waves. At the same time, metamaterials have extremely important applications in the fields of electromagnetic stealth, communication systems and imaging technology.

At present, although a band-stop filter in the infrared band can be realized based on the metamaterial, it is used to remove electromagnetic waves that are not required in the infrared band. However, due to its own resonant characteristics, the bandwidth tends to be relatively small. For the large bandwidth required for high-speed communication in the future, realizing the large bandwidth of the band-stop filter in the infrared band is an urgent problem to be solved. In addition, if the structure of the band rejection filter is not specially considered, the coupling efficiency between the structures is not high, thereby limiting the practical application of the structure.

Summary of the invention

Based on this, it is necessary to provide a band rejection filter for how to realize the large bandwidth problem of the band rejection filter in the infrared frequency band.

A band rejection filter comprising a filter unit structure, the filter unit structure including a first metal layer, a first dielectric layer, and a second metal layer; the first metal layer, the first dielectric layer, and The second metal layer is sequentially stacked; the first metal layer and the second metal layer have the same structure.

In one embodiment, the first metal layer and the second metal layer are metamaterial structures.

In one embodiment, the first metal layer and the second metal layer are both in a flat block shape, and the two opposite and largest areas of the first metal layer are the first side and the second side, respectively. The two opposite and largest areas of the second metal layer are respectively a third surface and a fourth surface; the first dielectric layer has a square pillar shape and has two end faces and four sides, wherein The two opposite and largest sides are the fifth side and the sixth side, respectively;

The first surface of the first metal layer is exposed, the second surface is bonded to the fifth surface of the first dielectric layer, and the third surface of the second metal layer and the sixth surface of the first dielectric layer Fit and expose the fourth side.

In one embodiment, the projection of the first metal layer on the first dielectric layer coincides with the projection of the second metal layer on the first dielectric layer.

In one embodiment, a complete projection of the first metal layer in the first dielectric layer is included in a fifth side of the first dielectric layer; the second metal layer is in the first dielectric layer A complete projection is included within the sixth side of the first dielectric layer.

In one embodiment, the geometric centers of the first metal layer, the first dielectric layer, and the second metal layer are on the same straight line.

In one embodiment, the filter unit structure further includes a second dielectric layer and a third metal layer; the first metal layer, the second metal layer, and the third metal layer are sequentially stacked; The first dielectric layer is stacked between the first metal layer and the second metal layer, and the second dielectric layer is laminated between the second metal layer and the third metal layer; The structure of one metal layer, the second metal layer, and the third metal layer is the same.

In one embodiment, the first dielectric layer has a length of 550 nm to 650 nm, a thickness of 190 nm to 200 nm, and a width of 235 nm to 245 nm; and the first metal layer and the second metal layer along the length The direction extends.

In one embodiment, the first metal layer and the second metal layer have the same structure, and have a length of 315 nm to 325 nm, a thickness of 24 nm to 28 nm, and a width of 75 nm to 85 nm.

In one of the embodiments, the band rejection filter includes a plurality of filter unit structures periodically arranged along a length direction and a width direction of the first dielectric layer.

The above-mentioned band rejection filter is formed by forming a filter unit structure by using a metal layer-dielectric layer-metal layer, and then forming a band rejection filter by periodically arranging a plurality of filter unit structures along a length direction and a width direction of the dielectric layer, the band The blocking filter allows electromagnetic waves in the infrared frequency range to pass, while the electromagnetic waves outside the infrared frequency range are attenuated to very low or reflected, and the bandwidth of the infrared band that can pass through can reach 120 THz, thereby satisfying the wide filtering band in the infrared frequency range. And can be applied to future high-speed communication.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings described below are merely For some embodiments of the present invention, those skilled in the art can obtain drawings of other embodiments according to the drawings without any creative work.

1 is a schematic structural diagram of a filter unit of a band rejection filter according to an embodiment;

2 is an exploded view showing a structure of a filter unit of a band rejection filter in another embodiment;

3 is a top plan view showing the structure of a filter unit of a band rejection filter in an embodiment;

4 is a front elevational view showing the structure of a filter unit of a band rejection filter in an embodiment;

Figure 5 is a side view showing the structure of a filter unit of a band rejection filter in an embodiment;

6 is a schematic plan view showing a planar structure of a band rejection filter according to an embodiment;

Fig. 7 is a graph showing the transmission characteristics of the band rejection filter in an embodiment.

detailed description

In order to facilitate the understanding of the present invention, the present invention will be described more fully hereinafter with reference to the accompanying drawings. Preferred embodiments of the invention are given in the drawings. However, the invention may be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be more fully understood.

It should be noted that when an element is referred to as being "fixed" to another element, it can be directly on the other element or the element can be present. When an element is considered to be "connected" to another element, it can be directly connected to the other element or. The terms "vertical", "horizontal", "left", "right", and the like, as used herein, are for the purpose of illustration and are not intended to be the only embodiment.

All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. The terminology used in the description of the present invention is for the purpose of describing particular embodiments and is not intended to limit the invention.

Please refer to FIG. 1 , which is a schematic structural diagram of a filter unit of a band rejection filter according to an embodiment. The filter unit structure may include a first metal layer 10, a first dielectric layer 20, and a second metal layer 30. The first metal layer 10, the first dielectric layer 20, and the second metal layer 30 are sequentially stacked. The structures of the first metal layer 10 and the second metal layer 30 are the same. The first metal layer 10 and the second metal layer 30 are metal conductive materials, for example, metals such as gold, silver, copper, iron, and aluminum. The material of the first dielectric layer 20 may be a non-conductor material such as silicon, quartz or the like. It may also be a flexible dielectric material such as a polyimide film. Of course, other flexible dielectric materials having similar dielectric constants and loss angles may also be used. Preferably, the first metal layer 10 and the second metal layer 30 are both made of silver, and the first dielectric layer 20 is made of silicon. The first dielectric layer 20 has a dielectric constant of 2.14, a loss tangent of 0.002, and a magnetic permeability of 1. Some of the key parameters that typically measure the performance of a dielectric layer are dielectric constant, loss tangent, and magnetic permeability. When the medium is applied with an electric field, an induced charge is generated to weaken the electric field. The ratio of the electric field in the medium to the original applied electric field (in vacuum) is the relative permittivity (dielectric constant), also known as the induced electric rate. Frequency related. The dielectric constant is the product of the relative dielectric constant and the absolute dielectric constant in vacuum, expressed as εr. The loss tangent is also called the dielectric loss tangent, and the dielectric loss tangent. A physical quantity that characterizes the dielectric loss of a dielectric material after application of an electric field, expressed as tan δ, which is the dielectric loss angle. It characterizes the ratio of the energy lost by the dielectric to its stored energy in each cycle. The magnetic permeability indicates the physical quantity of magnetic properties of the magnetic medium. The magnetic permeability μ is equal to the ratio of the differential of the magnetic induction B in the magnetic medium to the differential of the magnetic field strength H, that is, μ=dB/dH.

In one embodiment, the first metal layer 10 and the second metal layer 30 are both metamaterial structures. In other words, the first metal layer 10 and the second metal layer 30 have metamaterial structural characteristics such as a negative refractive index and a negative magnetic permeability.

In one embodiment, please refer to FIG. 2, which is an exploded view of the filter unit structure in an embodiment. The first metal layer 10 and the second metal layer 30 have the same structure, and each has a flat block shape. In other words, the shapes and structures of the first metal layer 10 and the second metal layer 30 are the same. The two opposite and largest areas of the first metal layer 10 are the first surface 110 and the second surface 120, respectively, and the two opposite and largest areas of the second metal layer 30 are the third surface 310 and the fourth surface, respectively. The first dielectric layer 20 has a square pillar shape and has two end faces and four side faces, wherein the two opposite and largest side faces are the fifth face 210 and the sixth face 220 respectively; the first metal layer 10 The first surface 110 is exposed, the second surface 120 is bonded to the fifth surface 210 of the first dielectric layer 20, and the third surface 310 of the second metal layer 30 is bonded to the sixth surface 220 of the first dielectric layer 20, The four sides of the 320 are exposed. The first metal layer 10 and the second metal layer 30 have the same structure, can be easily fabricated using the same reticle, reduce process complexity, and can also reduce production costs.

Specifically, the specific structure of the first metal layer 10 is taken as an example for description. It can be understood that since the structure of the second metal layer 30 is the same as that of the first metal layer 10, the description of the structure of the second metal layer 30 can be referred to Description of the first metal layer 10. The first metal layer 10 is a flat block structure, which may be a regular block shape or an irregular block structure. The irregularity is defined as follows: 1. The plane layout is complicated, and the size of the concave protrusion is super. Regulation, length and width ratio over-regulation, severe asymmetry; 2, vertical arrangement picking out, retreating into over-rule, serious asymmetry, wherein "regulation" refers to high-rise building concrete structure technical specification JGJ3-2010. Preferably, the first metal layer 10 is a regular block structure. Further, the first metal layer 10 may be a regular flat rectangular parallelepiped, a regular flat rectangular parallelepiped, or other regular flat block structures. Preferably, the first metal layer 10 is a regular flat rectangular parallelepiped. Referring to FIG. 2, the first metal layer 10 is a flat rectangular parallelepiped, wherein two opposite and largest areas are respectively a first surface 110 and a second surface 120. Accordingly, the second metal layer 30 also adopts a rectangular parallelepiped. In the case of a shape, there are also two opposite and the largest sides are the third side 310 and the fourth side 320, respectively. Here, the relative meaning can be understood as mirror symmetry, and the largest area refers to two sides having the largest relative area in the case of using a rectangular parallelepiped shape, where "first", "second" in the first metal layer 10, The "third" and "fourth" in the second metal layer 30 and the "fifth" and "sixth" in the first dielectric layer are not related in the order or composition, and are not limited, just for the purpose of distinction and The required plane is described, but also to make the description of the present invention clearer and more detailed. It can be understood that only two of the faces are listed here. Since it is a rectangular parallelepiped structure, there are four faces, which will not be further described here. The first dielectric layer 20 has a rectangular column shape. Illustratively, the first dielectric layer 20 may have a rectangular parallelepiped shape, wherein the first dielectric layer 20 has two end faces and four side faces, and the end faces are the two with the smallest relative areas. Face. The two end faces may be rectangular, square, or other shapes. Preferably, the first dielectric layer 20 is a rectangular parallelepiped having an end face, wherein the two opposite and largest side faces are a fifth face 210 and a sixth face 220, respectively. The relative meaning here can be understood as mirror symmetry, and the largest area refers to the two sides with the largest relative area in the case of a rectangular parallelepiped shape. The first surface 110 of the first metal layer 10 is exposed, the second surface 120 is bonded to the fifth surface 210 of the first dielectric layer 20, and the third surface 310 of the second metal layer 30 and the sixth surface of the first dielectric layer 20 are The first surface 110 of the first metal layer 10 is exposed, and the second surface 120 is attached to the fifth surface 210 of the first dielectric layer 20. It can be understood that the first metal The other faces of the layer 10 are also in a bare state, and only the side that is in contact with the fifth face 210 of the first dielectric layer 20, that is, the second face 120 is not exposed, and correspondingly, the other of the second metal layer 30 The face is also in a bare state, and only the side that is in contact with the sixth face 220 of the first dielectric layer 20, that is, the third face 310 is not exposed.

In one embodiment, the projection of the first metal layer 10 at the first dielectric layer 20 coincides with the projection of the second metal layer 30 at the first dielectric layer 20.

Specifically, the first metal layer 10 and the second metal layer 30 have the same structure. Here, as a regular flat rectangular parallelepiped, the projection of the first metal layer 10 in the first dielectric layer 20 and the second metal layer 30 are The projections of the first dielectric layer 20 are coincident, that is, the second surface 120 of the first metal layer 10, the third surface 310 of the second metal layer 30, and the fifth surface 210 and the sixth surface 220 of the first dielectric layer 20 The position of the fit is mirror-symmetrical, and since the structure is the same, the overall structure of the two is also mirror-symmetrical. Thus, when the electromagnetic wave is incident, the coupling between the first metal layer 10 and the second metal layer 30 is enhanced, thereby reducing the resonance frequency and broadening the bandwidth of the electromagnetic wave in the infrared frequency range that can pass.

In one embodiment, the complete projection of the first metal layer 10 in the first dielectric layer 20 is included in the fifth side 210 of the first dielectric layer 20; the complete projection of the second metal layer 30 in the first dielectric layer 20 is included in Within the sixth face 220 of the first dielectric layer 20.

In particular, the complete projection of the first metal layer 10 at the first dielectric layer 20 can be understood as a projection formed on the first dielectric layer 20 after a beam of light is incident perpendicularly from the first face 110 of the first metal layer 10. This projection is completely contained within the fifth face 210 of the first dielectric layer 20, that is, the first metal layer 10 is within the range of the fifth face 210 of the first dielectric layer 20, and may be anywhere within the range, as long as It is sufficient to ensure that the complete projection does not exceed the range of the fifth surface 210. Accordingly, the second metal layer 30, like the first metal layer 10, can be anywhere within the range as long as the full projection is not exceeded beyond the sixth surface 220. This maximizes the stability of the device while increasing the utilization of the metal layer.

In one embodiment, the geometric centers of the first metal layer 10, the first dielectric layer 20, and the second metal layer 30 are on the same straight line.

Specifically, the geometric centers of the first metal layer 10, the first dielectric layer 20, and the second metal layer 30 are on the same straight line, that is, the straight lines passing through the geometric centers of the three are coincident. This has the advantage of further ensuring the overall regularity of the device, so that the coupling between the first metal layer 10 and the third metal layer 30 is further enhanced.

Please refer to FIG. 3, FIG. 4 and FIG. 5, which are respectively a top view, a front view and a side view of the filter unit structure in an embodiment. As shown in FIG. 3, the model parameters of the filter unit structure in the present embodiment are represented by Lx, Ly, Sx, Sy, h1, h2, h3, respectively. Wherein, Lx represents the length of the filter unit structure, that is, the length of the first dielectric layer 20. Ly represents the width of the filter unit structure, that is, the width of the first dielectric layer 20. Sx represents the length of the first metal layer 10 and the second metal layer 30; Sy represents the width of the first metal layer 10 and the second metal layer 30; h1 represents the thickness of the first metal layer 10; h2 represents the first dielectric layer 20 The thickness; h3 represents the thickness of the second metal layer 30. The first metal layer 10 and the second metal 30 extend along the length direction of the first dielectric layer 20, that is, in the direction of the X-axis in the drawing. It can be understood that the model parameters of the filter unit structure are not particularly limited, and the model parameters are well known to those skilled in the art, and those skilled in the art can select and adjust according to actual conditions and product performance. The present invention preferably has 550 nm- Lx-650um, 235 nm-Ly-245 nm, 190 nm-h2-200 nm, 315 nm-Sx-325 nm, 75 nm-Sy-85 nm, 24 nm-h1-28 nm, 24 nm-h3-28 nm. More preferably, it is 550 nm-Lx-600 um, 235 nm-Ly-240 nm, 190 nm-h2-195 nm, 315 nm-Sx-320 nm, 75 nm-Sy-80 nm, 24 nm-h1-26 nm, and 24 nm-h3-26 nm is most preferably 600 nm-Lx. -650 um, 240 nm-Ly-245 nm, 195 nm-h2-200 nm, 320 nm-Sx-325 nm, 80 nm-Sy-85 nm, 26 nm-h1-28 nm, 26 nm-h3-28 nm. Illustratively, the specific structure of the preferred filter unit structure of the present invention is described by a specific parametric model, that is, the selection of each model parameter of the filter unit structure may be: Lx=600 nm, Ly=240 nm, Sx=320 nm, Sy = 80 nm, h1 = 26 nm, h2 = 195 nm, and h3 = 26 nm. Preferably such parameters may optimize the overall performance of the filter unit structure and, since the size is chosen to be on the order of microns, the overall size after formation of the terahertz band stop filter is not excessive.

Please refer to FIG. 6 , which is a schematic diagram of a planar structure of a band rejection filter in an embodiment. The band rejection filter may include a plurality of filter unit structures periodically arranged along the length direction and the width direction of the first dielectric layer 20 , where The direction of the length and the direction of the width can be understood as the horizontal direction and the vertical direction. It can be understood that the number of the filter unit structures arranged in the horizontal direction (longitudinal direction) and the number arranged in the vertical direction (width direction) may be the same or different, for example, the same number of cases: the filter unit structure is horizontal 10 (longitudinal direction) are arranged, 10 are arranged in the vertical direction (width direction); the number is different: the filter unit structure is arranged in the horizontal direction (longitudinal direction) 12, and the vertical direction (width direction) is arranged 13 . The present invention is not particularly limited in the number of the filter unit structures arranged in the horizontal direction (longitudinal direction) and the vertical direction (width direction), and can be used by those skilled in the art according to the actual operation needs and products. Performance selection and adjustment. Preferably, the band rejection filter of the present invention has a 3*2 array structure, that is, three filter unit structures are arranged in the horizontal direction (longitudinal direction), and two filter unit structures are arranged in the vertical direction (width direction).

In the above embodiment, the filter unit structure is formed by using a metal layer-dielectric layer-metal layer, and then a band rejection filter is formed by periodically arranging a plurality of filter unit structures along the length direction and the width direction of the dielectric layer, the band rejection filter The electromagnetic wave in the infrared frequency range can be passed, and the electromagnetic wave outside the infrared frequency range is attenuated to be extremely low or reflected, and the bandwidth of the infrared frequency band that can be passed can reach 120 THz, thereby satisfying the wide filtering frequency band in the infrared frequency band range, and Can be applied to future high-speed communication.

In one embodiment, a band rejection filter may include a plurality of periodically arranged filter unit structures, and the filter unit structure may include: a first metal layer 10, a first dielectric layer 20, and a second metal layer 30, The second dielectric layer (not shown) and the third metal layer (not shown). The first metal layer 10, the second metal layer 30, and the third metal layer (not shown) are sequentially stacked. The first dielectric layer 20 is laminated between the first metal layer 10 and the second metal layer 30, and the second dielectric layer (not shown) is laminated between the second metal layer 30 and the third metal layer (not shown). The first metal layer 10, the second metal layer 30, and the third metal layer (not shown) have the same structure. Wherein, the plurality of filter unit structures may be periodically arranged along the length direction and the width direction of the first dielectric layer 20 to form a band rejection filter.

In one embodiment, for the structural description of the third metal layer (not shown), reference may be made to the description of the first metal layer 10 in the foregoing embodiment, for the third metal layer (not shown), the second metal layer 30, For the relative positional relationship between the second dielectric layers (not shown), reference may be made to the foregoing description of the relative positional relationship with the first metal layer 10, the first dielectric layer 20, and the second metal layer 30, for the third metal. The bonding relationship between the layer (not shown) and the second dielectric layer (not shown), and the bonding relationship between the second dielectric layer (not shown) and the second metal layer 30 can be referred to the foregoing first metal layer 10 The description of the bonding relationship between the first dielectric layer 20 and the second metal layer 30 will not be further described herein.

In one embodiment, the second dielectric layer (not shown) may be the same as the first dielectric layer 20, and may be a non-conductor material or a flexible dielectric material. The material of the present invention for the second dielectric layer (not shown). It is not particularly limited, and the materials are well known to those skilled in the art, and those skilled in the art can select and adjust according to actual conditions and product performance. The second medium layer (not shown) and the first dielectric layer 20 are preferred in the present invention. Like the materials, all are silicon or quartz, most preferably silicon. The material selection of the first dielectric layer 20 and the second dielectric layer (not shown) is preferably the same, which ensures the overall performance of the band rejection filter. However, it can be understood that the first dielectric layer 20 and the second dielectric layer (not shown) may also be selected from different materials. For example, the material of the first dielectric layer 20 is selected from quartz, and the second dielectric layer (not shown). The material is selected from silicon, and of course, it can be reversed or other materials can be used. The dielectric constant of the second dielectric layer (not shown) is not particularly limited, and the dielectric constant is well known to those skilled in the art, and those skilled in the art can select and adjust according to actual conditions and product performance. The dielectric constant of the preferred second dielectric layer (not shown) of the invention is the same as the dielectric constant of the first dielectric layer 20, which is 2.14. The loss tangent of the second dielectric layer (not shown) is not particularly limited, and the tangent tangent is well known to those skilled in the art, and those skilled in the art can select and adjust according to actual conditions and product performance. Preferably, the lossy tangent of the second dielectric layer (not shown) is the same as that of the first dielectric layer 20, both being 0.002. The magnetic permeability of the second dielectric layer (not shown) is not particularly limited, and the magnetic permeability is well known to those skilled in the art, and those skilled in the art can select and adjust according to actual conditions and product performance. Preferably, the magnetic permeability of the second dielectric layer (not shown) is the same as that of the first dielectric layer 20.

In the above embodiment, the filter unit structure is formed by using a metal layer-dielectric layer-metal layer-dielectric layer-metal layer, and then band-stop filtering is formed by periodically arranging a plurality of filter unit structures along the length direction and the width direction of the dielectric layer. The band-stop filter allows electromagnetic waves in the infrared range to pass, while electromagnetic waves outside the infrared range are attenuated to very low or reflected, making the band-stop filter super-material, while meeting the infrared range Wide filter band and can be applied to future high-speed communication.

In order to make the present invention more detailed, the principles of the present invention are further described below in conjunction with FIG.

Please refer to FIG. 7, which is a transmission characteristic diagram of the band rejection filter in an embodiment. Based on the description of the above embodiment, a specific simulation condition is set by establishing a model of the filter unit structure in the three-dimensional electromagnetic simulation software, a magnetic field is applied in the X-axis direction, and an electric field is applied in the Y-axis direction, and the electromagnetic wave is incident perpendicularly to the band stop. The filter surface (i.e., the electromagnetic wave is incident on the surface of the band stop filter along the Z-axis direction), that is, incident along the end face of the first dielectric layer 20. The relationship between the transmittance and the frequency of the band rejection filter of the present invention is obtained by simulation. As shown in FIG. 7, it can be seen from the figure that the center frequency f _{0 is} approximately equal to 255 THz, and the 3 dB band-stop bandwidth of the band rejection filter is 120 THz, and the corresponding frequency is 195 THz-315 THz. In summary, the present invention is A band rejection filter can be applied to an infrared communication system.

The technical features of the above-described embodiments may be arbitrarily combined. For the sake of brevity of description, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, All should be considered as the scope of this manual.

The above-described embodiments are merely illustrative of several embodiments of the present invention, and the description thereof is more specific and detailed, but is not to be construed as limiting the scope of the invention. It should be noted that a number of variations and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of the invention should be determined by the appended claims.

Claims

A band rejection filter, comprising: a filter unit structure, the filter unit structure including a first metal layer, a first dielectric layer, and a second metal layer; the first metal layer, the first The dielectric layer and the second metal layer are sequentially stacked; the first metal layer and the second metal layer have the same structure.
The band rejection filter according to claim 1, wherein the first metal layer and the second metal layer are of a metamaterial structure.
The band rejection filter according to claim 2, wherein the first metal layer and the second metal layer are both in a flat block shape, and two of the first metal layers are opposite and the largest area The sides are respectively a first surface and a second surface, and the two opposite and largest areas of the second metal layer are respectively a third surface and a fourth surface; the first dielectric layer is in the shape of a square cylinder and has Two end faces and four sides, wherein the two opposite and largest sides are the fifth side and the sixth side, respectively;

The first surface of the first metal layer is exposed, the second surface is bonded to the fifth surface of the first dielectric layer, and the third surface of the second metal layer and the sixth surface of the first dielectric layer Fit and expose the fourth side.
The band rejection filter according to claim 3, wherein the projection of the first metal layer on the first dielectric layer coincides with the projection of the second metal layer on the first dielectric layer.
The band rejection filter according to claim 4, wherein a complete projection of the first metal layer in the first dielectric layer is included in a fifth side of the first dielectric layer; A complete projection of the metal layer in the first dielectric layer is included in a sixth side of the first dielectric layer.
The band rejection filter according to claim 3, wherein the geometric centers of the first metal layer, the first dielectric layer, and the second metal layer are on the same straight line.
The band rejection filter according to any one of claims 3-6, wherein the filter unit structure further comprises a second dielectric layer and a third metal layer; the first metal layer, the The second metal layer and the third metal layer are sequentially stacked; the first dielectric layer is laminated between the first metal layer and the second metal layer, and the second dielectric layer is laminated on the Between the second metal layer and the third metal layer; the first metal layer, the second metal layer, and the third metal layer have the same structure.
The band rejection filter according to any one of claims 3-6, wherein the first dielectric layer has a length of 550 nm to 650 nm, a thickness of 190 nm to 200 nm, and a width of 235 nm to 245 nm; The first metal layer and the second metal layer extend in the direction of the length.
The band rejection filter according to any one of claims 3-6, wherein the first metal layer and the second metal layer have the same structure and have a length of 315 nm to 325 nm and a thickness of 24 nm. 28 nm, width 75 nm - 85 nm.
The band rejection filter according to claim 8, wherein the band rejection filter includes a plurality of filter unit structures periodically arranged along a length direction and a width direction of the first dielectric layer.