WO2012155472A1

WO2012155472A1 - High transmission antenna

Info

Publication number: WO2012155472A1
Application number: PCT/CN2011/082326
Authority: WO
Inventors: 刘若鹏; 季春霖; 岳玉涛
Original assignee: 深圳光启高等理工研究院; 深圳光启创新技术有限公司
Priority date: 2011-05-18
Filing date: 2011-11-17
Publication date: 2012-11-22

Abstract

A high transmission antenna comprises a radiation source and an electromagnetic wave converging element working at the first wave length. The electromagnetic is used for converting an electromagnetic wave emitted from the radiation source into a plane wave and make the antenna working simultaneously at the second and third wave length that are shorter than the first wave length and are multiple of the first wave length. The electromagnetic wave converging element comprises a plurality of concentric circular ring bodies with concave top surfaces and planar bottom surfaces, and the thickness of each circular ring body gradually increases as a radius increases, so as to make a reflective wave generated, when the electromagnetic wave emitted from the radiation source is incident on the top surface, interfere with a reflective wave generated, when the electromagnetic wave emitted from the radiation source is incident on the bottom surface, thus cancelling each other. The high transmission antenna can work at the different wave length simultaneously by designing the working wave length of the electromagnetic wave converging element, the thickness of the metamaterial changes as the refractive index changes, so it need not an impedance matching layer.

Description

High transmission antenna

[Technical Field]

This invention relates to the field of antennas and, more particularly, to a highly transmissive antenna. 【Background technique】

Metamaterials are a new type of material that consists of a substrate made of a non-metallic material and a plurality of artificial microstructures attached to or embedded in the surface of the substrate. The artificial microstructure is a cylindrical or flat wire constituting a certain geometric figure, for example, a wire forming an annular shape, an I shape, or the like. Each artificial microstructure and part of the substrate attached or occupied constitutes a unit, and the entire metamaterial is composed of hundreds, thousands, millions or even hundreds of millions of such units, just as crystals are made up of countless lattices. Each crystal lattice is equivalent to the above-mentioned artificial microstructure and a unit composed of a part of the substrate.

Due to the existence of artificial microstructures, each of the above units has an equivalent dielectric constant and equivalent magnetic permeability different from the substrate itself, so that all the metamaterials formed by the unit exhibit special response characteristics to electric and magnetic fields; At the same time, the specific structure and shape of the artificial microstructure can be changed, and the equivalent dielectric constant and equivalent magnetic permeability of the unit can be changed, thereby changing the response characteristics of the entire metamaterial.

When electromagnetic waves pass through the same medium, there is basically no loss of energy; and when electromagnetic waves pass through the interface of different media, partial reflection occurs. Generally, the larger the electromagnetic parameter (dielectric constant or magnetic permeability) of the two sides of the medium, the larger the reflection will be. Due to the reflection of some electromagnetic waves, the electromagnetic energy along the propagation direction will be correspondingly lost, which seriously affects the distance of electromagnetic signal propagation and the quality of the transmitted signal. In the design of the existing metamaterial-based antenna, in order to avoid the change of the refractive index, the reflection is generated when the electromagnetic wave propagates, and the reflection interference and loss are reduced. Usually, an impedance matching layer is added on the super material panel to reduce the reflection loss. As shown in FIG. 1, an impedance matching layer 30 is added to the metamaterial panel 10, and electromagnetic waves emitted from the radiation source 20 are concentrated by the impedance matching layer 30 and the metamaterial panel 10, and are emitted as plane waves. This not only increases the thickness of the metamaterial film, but also increases the manufacturing cost, while increasing the size of the antenna and the difficulty of fabrication and installation using the metamaterial.

Moreover, usually an antenna can only work at one operating frequency point, at a different frequency than its working frequency. Other frequency points cannot respond.

[Summary of the Invention]

The technical problem to be solved by the present invention is to provide a high-transmittance antenna for the defects of the prior art that are single, large in size, and high in cost.

The technical solution adopted by the present invention to solve the technical problem thereof is: providing a high-transmittance antenna, comprising: a radiation source and an electromagnetic wave concentrating element having an electromagnetic wave concentrating function and operating at a first wavelength; the electromagnetic wave concentrating element comprising a plurality of tops a concentric annular body having a concave surface and a flat bottom surface and a filling body filled on the concave surface of the plurality of concentric annular bodies; the thickness of each annular body gradually increasing with increasing radius, so that the radiation source is emitted The reflected wave generated when the electromagnetic wave is incident on the concave surface interferes with the reflected wave generated when the electromagnetic wave is incident on the bottom surface, and cancels each other, and the electromagnetic wave concentrating element is used to convert the electromagnetic wave emitted by the radiation source a plane wave and causing the antenna to operate simultaneously on the second wavelength and the third wavelength, the second wavelength and the third wavelength are both smaller than the first wavelength, and the first wavelength is an integer of the second wavelength or the third wavelength The filling body is such that the top surface of the plurality of concentric annular bodies is flat and parallel to the bottom surface, and the refractive index of the filling body the same;

Wherein, the refractive index of each torus decreases continuously from n _m to n _n and the refractive index at the same radius increases with the radius, and the thickness d of the electromagnetic wave converging element satisfies the following formula: d(r) = , ^ ~~ ,

- ⁷ # ⁷ 3⁄4

(S is the distance from the radiation source to the electromagnetic wave concentrating element, is the first wavelength, d ₀ = ~ ^ ^ , n _m is the maximum refractive index of each torus, and 3⁄4 is the minimum refractive index of each torus , L(i) is the starting radius of the i-th torus from the inside to the outside where the radius r is located, and J(1) = 0).

In the high transmission antenna of the present invention, each annular body is provided with a plurality of artificial microstructures, and the plurality of artificial microstructures continuously reduce the refractive index of each torus from n _m as the radius increases. The refractive index is the same at 3⁄4 and at the same radius.

In the high transmission antenna of the present invention, the plurality of artificial microstructures have the same geometry, And the size of the artificial microstructure of each torus continuously decreases with increasing radius and the dimensions of the artificial microstructure at the same radius are the same.

In the high transmission antenna according to the present invention, the artificial microstructure is a planar structure or a three-dimensional structure composed of at least one wire.

In the high transmission antenna of the present invention, the wire is a copper wire or a silver wire.

In the high transmission antenna of the present invention, the wire is attached to each of the toroids by etching, electroplating, drilling, photolithography, electron engraving or ion engraving.

In the high transmission antenna according to the present invention, the refractive index of the filler body is equal to or less than n _n .

In the high transmission antenna according to the present invention, the filler has a refractive index of 1.

Another technical solution for solving the technical problem of the present invention is to provide: a high-transmittance antenna comprising a radiation source and an electromagnetic wave concentrating element having an electromagnetic wave concentrating function and operating at a first wavelength, wherein the electromagnetic wave concentrating element is used for The electromagnetic wave emitted by the radiation source is converted into a plane wave and causes the antenna to simultaneously operate at a second wavelength and a third wavelength that are smaller than the first wavelength and have a different multiple relationship with the first wavelength; the electromagnetic wave concentrating element The invention comprises a plurality of concentric annular bodies whose top surface is concave and whose bottom surface is a plane. The thickness of each annular body gradually increases with the increase of the radius, so that the reflected wave generated when the electromagnetic wave emitted by the radiation source is incident on the IHJ surface The reflected waves generated when incident on the bottom surface interfere with each other and cancel each other.

In the high-transmittance antenna according to the present invention, the refractive index of each annular body decreases from continuous to "" and the refractive index at the same radius increases with the increase of the radius, and the thickness d of the electromagnetic wave concentrating element satisfies the following Formula:

d(r) = , ^ ~~ ,

- ⁷ # ⁷ 3⁄4 where S is the distance from the radiation source to the electromagnetic wave collecting element, which is the first wavelength, d ₀ = ~ ^ ^ , n _m is the maximum refractive index of each torus, 3⁄4 is each circle The minimum refractive index of the ring, L(i) is the starting radius of the i-th torus from the inside to the outside where the radius r is, and J(1) = 0. In the high transmission antenna of the present invention, each annular body is provided with a plurality of artificial microstructures, and the plurality of artificial microstructures continuously reduce the refractive index of each torus from n _m as the radius increases. The refractive index is the same at 3⁄4 and at the same radius.

In the high transmission antenna of the present invention, the plurality of artificial microstructures have the same geometry, and the size of the artificial microstructure of each torus continuously decreases with increasing radius and artificial at the same radius The microstructures are the same size.

In the high-transmitting antenna of the present invention, the electromagnetic wave concentrating element further includes a filler body filled on a concave surface of the plurality of concentric annular bodies, the filler body making a top of the plurality of concentric annular bodies The face is flat and parallel to the bottom surface, and the refractive index of the filler body is the same everywhere.

The technical solution of the present invention has the following beneficial effects: By designing the working wavelength of the electromagnetic wave concentrating component, the antenna can work at different wavelengths at the same time, and when there are different frequency requirements, the antenna can be realized without replacing the antenna. By designing the thickness of the metamaterial itself to vary with the refractive index, the metamaterial film itself can attenuate the reflection loss without the need to add an impedance matching layer. It not only reduces reflection interference and loss, but also enhances transmission performance. It also reduces the thickness of the metamaterial film, reduces the manufacturing cost, and reduces the size of the antenna and the difficulty of fabrication and installation.

[Description of the Drawings]

1 is a schematic structural view of a conventional antenna including an impedance matching layer;

2 is a partial schematic structural view of an electromagnetic wave concentrating element in a high transmission antenna according to an embodiment of the invention; 3 is a flow chart of a method for generating an operating wavelength of the electromagnetic wave concentrating element 200 of FIG. 2; FIG. 4 is a schematic diagram of a refractive index as a function of a radius;

Figure 5 is a schematic cross-sectional view of the electromagnetic wave concentrating element 200 of Figure 2;

Figure 6 is a graph showing the refractive index profile of the electromagnetic wave concentrating element 200 in the yz plane.

【detailed description】

The invention will now be described in detail in conjunction with the drawings and embodiments.

The optical path of the electromagnetic wave inside the metamaterial film is l=n*d, d is the thickness of the metamaterial film, and n is the refractive index. When electromagnetic waves pass through the metamaterial film, they form a reflection on both sides of the metamaterial film (on both boundary surfaces of the metamaterial film when entering the metamaterial and when the metamaterial is propagated). When the optical path of the electromagnetic wave in the film is one quarter of the wavelength, the reflected wave generated when entering the metamaterial film is exactly π /2 out of phase with the reflected wave generated when the film is propagated, so that the two reflected waves will occur. Interfere with each other and eliminate each other. According to the principle of conservation of energy, the sum of the reflected energy and the transmitted energy is a fixed value, so that the reflected waves cancel each other to enhance the electromagnetic wave energy transmitted through the film and enhance the transmission performance. Thus, by designing the thickness of the metamaterial itself as a function of the refractive index, the metamaterial film itself has the effect of attenuating the reflection loss, and there is no need to add an impedance matching layer.

2 is a partial schematic structural view of an electromagnetic wave concentrating element in a high transmission antenna according to an embodiment of the present invention. The high transmission antenna includes a radiation source and an electromagnetic wave concentrating element (made of metamaterial) having an electromagnetic wave concentrating function and operating at a first wavelength, and the electromagnetic wave concentrating element is configured to convert electromagnetic waves emitted by the radiation source into plane waves and simultaneously make the antenna Working at a second wavelength λ ₂ and a third wavelength λ ₃ that are smaller than the first wavelength and are different from the first wavelength, that is, the antenna operates at the second wavelength λ ₂ and the third wavelength λ ₃ simultaneously The second wavelength λ ₂ and the third wavelength λ ₃ are both smaller than the first wavelength, and the first wavelength is an integer multiple of the second wavelength λ ₂ or the third wavelength λ ₃ . For the sake of simplicity of description, only the electromagnetic wave concentrating element 200 is shown, and the electromagnetic wave concentrating element 200 herein has not only the function of the metamaterial panel 10 shown in FIG. 1, but also the function of the impedance matching layer 30, which is not shown. The radiation source used in the present invention can use any radiation device available in the prior art, as shown in FIG. 1, and the specific structure will not be described again. If desired antenna operating in two different frequency points, the two frequencies corresponding to wavelengths of a second wavelength λ _2, λ _3, it is necessary to calculate a first wavelength electromagnetic wave converging on the working element 200 into _a third wavelength The λ ^ generation process is shown in Figure 3, which is detailed as follows:

Step 301: Acquire a value m ₃ / m ₂ (m ₃ and m ₂ are positive integers) in which the ratio λ ₃ / λ _{2 of the} third wavelength λ ₃ and the second wavelength λ ₂ is within a preset error range; preset error The range can be set according to the calculation accuracy, such as 0.01 and so on.

Step 302: Calculating the least common multiple of m ₂ and m ₃

Step 303: Generate an operating wavelength of the electromagnetic wave concentrating element 200, which can be expressed as: A i= A ₂ ( _mi / m ₂ ) or into the corpse 3 ( mi / m ₃ ).

Taking ₂ = 2cm and A ₃ = 3cm as an example, the λ corpse can be obtained by the above calculation process.

As can be seen from FIG. 2, the electromagnetic wave concentrating element 200 includes a plurality of concentric annular bodies whose top surface is concave and whose bottom surface is flat. The thickness of each annular body gradually increases with the increase of the radius, so that electromagnetic waves emitted by the radiation source are incident on the electromagnetic wave. The reflected wave generated when the IHJ surface interferes with the reflected wave generated when the electromagnetic wave is incident on the bottom surface cancels each other; the refractive index of each annular body continuously decreases from n _m to n _n as the radius increases The refractive index at the same radius is the same, and the refractive index changes with radius as shown in Fig. 4. In order to more clearly explain the shape and structure of the electromagnetic wave concentrating element 200, only half of each torus is shown in the drawing, and since each torus is symmetrically distributed, only the toroidal body is shown. For convenience of description, only three torus bodies are shown, and the torus bodies 1 to 3 can be set according to actual needs, as long as the electromagnetic waves are converted into plane waves. The oblique line portion of the figure shows a section of the electromagnetic wave concentrating element 200 in the YX plane, as shown in FIG. 5, 31 in FIG. 5 shows a section of the torus 1 in FIG. 2, and 32 in FIG. The section of the torus 2, 33 in Fig. 5, shows the section of the torus 3 in Fig. 2. The X direction is the direction in which the thickness d is located.

Wherein, the thickness d of the electromagnetic wave concentrating element 200 satisfies the following formula: d(r) = _{/ 2 / 2 2}

- 3⁄4 /3⁄4 where s is the distance from the radiation source to the electromagnetic wave collecting element, which is the first wavelength, d ₀ = ~ ^ ^ , n _m is the maximum refractive index of each torus, 3⁄4 is the minimum refractive index of each torus, L(i) is the radius from the inner to the outer i-th ring The starting radius, and J(1) = 0. If you want to calculate the thickness of a certain circle of the first torus (actually a circle), where the radius from the center of the circle is r, then J in the above equation (0 = (1); if you want to calculate the second The thickness of a circle of a circle where the radius from the center of the circle is r, then J( ) = (2) in the above formula; if the thickness of a certain portion of the third torus is to be calculated, The radius from the center of the circle is r, then J( ) = J(3) in the above equation. As shown in Figure 5, the starting radius of the first ring is J(1) = 0; the second ring The starting radius is J(2); the starting radius of the third ring is J(3).

A set of experimental data is given below. The frequency of the incident electromagnetic wave is f=15 GHz, the wavelength is 2 cm, n _max =6, n _mm =l, s=20 cm, L(l)=0cm, L(2)=9.17cm, L (3) = 13.27 cm, L (4) = 16.61 cm. In this example, the width of the first torus is 9.17 cm, the width of the second torus is (13.27-9.17) cm, and the width of the third torus is 13.27 cm, L(4)=(16.61- 13.27) cm.

An electromagnetic wave concentrating element satisfying the above refractive index change relationship, the electromagnetic wave diverging in the form of a spherical wave emitted from the radiation source is centered on the metamaterial unit having a refractive index of n _m , and the electromagnetic wave concentrating element is on the yz plane as the radius increases The amount of change in the refractive index gradually increases. As the radius increases, the angle of deflection of the incident electromagnetic wave is large, and the electromagnetic wave incident on the metamaterial unit near the center of the circle has a smaller deflection angle. Through certain design and calculation, these deflection angles are sequentially satisfied to a certain regularity, and spherical electromagnetic waves can be parallelly emitted. Similar to a convex lens, as long as the deflection angle of each surface point and the refractive index of the material are known, the corresponding surface curvature feature can be designed to make the divergent light microstructure incident from the lens focus, and obtain the dielectric constant ε and magnetic of the unit. The conductivity μ, and thus the refractive index of the metamaterial panel 10, can be converted into an electromagnetic wave in a planar form by the electromagnetic wave diverging in the form of a spherical wave.

In order to more intuitively represent the refractive index distribution of the super-material sheet on the yz plane, the super-material units with the same refractive index are connected into a line, and the density of the line is used to indicate the size of the refractive index. The larger the refractive index distribution of each core layer of the super material sheet conforming to all the above relationships, as shown in Fig. 6, the maximum refractive index is n _m and the minimum refractive index is n _n . A plurality of artificial microstructures are disposed in each of the annular bodies, the plurality of artificial microstructures such that the refractive index of each of the torus decreases continuously from n _m to 3⁄4 with the increase of the radius and the refractive index is the same at the same radius . Specific

The plurality of artificial microstructures have the same geometry, and the dimensions of the artificial microstructures of each torus continuously decrease with increasing radius and the dimensions of the artificial microstructures at the same radius are the same.

Experiments have shown that the artificial microstructure of the same pattern has a geometric dimension proportional to the dielectric constant ε. Therefore, in the case where the incident electromagnetic wave is determined, the electromagnetic wave is concentrated by rationally designing the topographic pattern of the artificial microstructure and the artificial microstructure of different sizes. The arrangement in the component can adjust the refractive index distribution of the electromagnetic wave concentrating element, thereby converting the electromagnetic wave diverging in the form of a spherical wave into an electromagnetic wave in a planar form.

There are many achievable ways to realize the above-mentioned artificial microstructures of the relationship between the refractive index and the refractive index change. For an artificial microstructure of a planar structure, the geometry may be axisymmetric or non-axisymmetric; for a three-dimensional structure, it may be non- Any three-dimensional graphics that are rotationally symmetric at 90 degrees.

The artificial microstructure is a planar structure or a three-dimensional structure composed of at least one wire. The wire is a copper wire or a silver wire which can be attached to the substrate by etching, plating, drilling, photolithography, electron engraving or ion etching.

The electromagnetic wave concentrating element as described above may have the shape shown in Fig. 2, and may of course be other desired shapes as long as it satisfies the refractive index change rule and the thickness variation rule described above.

In order to facilitate the fabrication and installation of the electromagnetic wave concentrating element, the concave surface of the plurality of concentric annular bodies of the electromagnetic wave concentrating element may be filled with a material to form a filling body such that the top surface of the plurality of concentric annular bodies is flat and bottom surface Parallel, and the refractive index of the filling body is the same, and the refractive index thereof may be a value less than or equal to η _η , such as but not limited to 1.

The invention designs the working wavelength of the electromagnetic wave concentrating component, so that the antenna can work at different wavelengths at the same time, and can be realized without changing the antenna when there are different frequency requirements. By changing the shape and structure of the electromagnetic wave concentrating element itself, the electromagnetic wave passes through the electromagnetic wave concentrating element, and its reflection loss is reduced, so that it has the function of attenuating reflection interference and loss.

The embodiments of the present invention have been described above with reference to the drawings, but the present invention is not limited to the specific embodiments described above, and the specific embodiments described above are merely illustrative and not restrictive. It will be apparent to those skilled in the art that many forms may be made without departing from the spirit and scope of the invention as claimed.

Claims

Rights request

1. A high transmission antenna, comprising:

a radiation source and an electromagnetic wave concentrating element having an electromagnetic wave concentrating function and operating at a first wavelength; the electromagnetic wave concentrating element comprising a plurality of concentric annular bodies having a concave top surface and a flat bottom surface and filling the plurality of concentric annular bodies a filler on the concave surface;

The thickness of each annular body gradually increases as the radius increases, so that the reflected wave generated when the electromagnetic wave emitted from the radiation source is incident on the IHJ surface interferes with the reflected wave generated when the electromagnetic wave is incident on the bottom surface. Offset each other, and the electromagnetic wave concentrating element is configured to convert electromagnetic waves emitted by the radiation source into plane waves and cause the antenna to operate simultaneously on the second wavelength and the third wavelength, the second wavelength and the third wavelength are both Less than the first wavelength, and the first wavelength is an integer multiple of the second wavelength or the third wavelength;

The filling body is such that a top surface of the plurality of concentric annular bodies is flat and parallel to the bottom surface, and the refractive index of the filling body is the same everywhere;

Wherein, the refractive index of each annular body is continuously reduced from n _m to n _n and the refractive index at the same radius is the same as the radius increases, and the thickness d of the electromagnetic wave converging element satisfies the following formula:

d(r) = , ^ ~~ ,

- ⁷ # ⁷ 3⁄4 where S is the distance from the radiation source to the electromagnetic wave collecting element, which is the first wavelength, d ₀ = ~ ^ ^ , n _m is the maximum refractive index of each torus, 3⁄4 is each circle The minimum refractive index of the ring, L(i) is the starting radius of the i-th torus from the inside to the outside where the radius r is, and J(1) = 0.

2. The high transmission antenna according to claim 1, wherein each annular body is provided with a plurality of artificial microstructures, such that the refractive index of each annular body increases with radius The n _{m is} continuously reduced to 3⁄4 and the refractive index at the same radius is the same.

3. The high transmission antenna according to claim 2, wherein the plurality of artificial microstructures have the same geometric shape, and the size of the artificial microstructure of each annular body continuously increases with a radius The dimensions of the artificial microstructures at the same radius are reduced and the same.

The high transmission antenna according to claim 3, wherein the artificial microstructure is a planar structure or a three-dimensional structure composed of at least one wire.

The high transmission antenna according to claim 4, wherein the wire is a copper wire or a silver wire.

6. The high transmission antenna according to claim 4, wherein the wire is attached to each of the toroids by etching, plating, drilling, photolithography, electron engraving or ion engraving.

The high transmission antenna according to claim 1, wherein the filler has a refractive index of 3⁄4 or less.

The high transmission antenna according to claim 1, wherein the filler has a refractive index of 1.

A high-transmitting antenna, comprising: a radiation source and an electromagnetic wave concentrating element having an electromagnetic wave concentrating function and operating at a first wavelength, wherein the electromagnetic wave concentrating element is configured to convert electromagnetic waves emitted by the radiation source into plane waves and Having the antenna simultaneously operate at a second wavelength and a third wavelength that are less than the first wavelength and are in a multiple of the first wavelength;

The electromagnetic wave concentrating element comprises a plurality of concentric annular bodies whose top surface is concave and whose bottom surface is a plane, and the thickness of each annular body gradually increases as the radius increases, so that electromagnetic waves emitted by the radiation source are incident on the concave surface. The generated reflected wave interferes with the reflected wave generated when incident on the bottom surface, and cancels each other.

10. The high transmission antenna according to claim 9, wherein the refractive index of each annular body is continuously reduced from n _m to 3⁄4 as the radius increases, and the refractive index is the same at the same radius, the electromagnetic wave The thickness d of the concentrating component satisfies the following formula:

d(r) = , ^ ~~ ,

- ⁷ # ⁷ 3⁄4 where S is the distance from the radiation source to the electromagnetic wave collecting element, which is the first wavelength, d ₀ = ~ ^ ^ , n _m is the maximum refractive index of each torus, 3⁄4 is each circle Minimum refractive index of the ring, L(i) The starting radius of the i-th torus from the inside to the outside where the radius r is located, and J(1) = 0.

11. The high transmission antenna according to claim 10, wherein each of the annular bodies is provided with a plurality of artificial microstructures, and the plurality of artificial microstructures increase the refractive index of each of the toroids with an increase in radius The n _{m is} continuously reduced to n _n and the refractive indices at the same radius are the same.

12. The high transmission antenna according to claim 11, wherein the plurality of artificial microstructures have the same geometry, and the size of the artificial microstructure of each torus continuously decreases as the radius increases. And the size of the artificial microstructure at the same radius is the same.

The high transmission antenna according to claim 12, wherein the artificial microstructure is a planar structure or a three-dimensional structure composed of at least one wire.

The high transmission antenna according to claim 13, wherein the wire is a copper wire or a silver wire.

15. The high transmission antenna according to claim 13, wherein the wire is attached to each of the toroids by etching, plating, drilling, photolithography, electron engraving or ion engraving.

The high-transmitting antenna according to claim 9, wherein the electromagnetic wave concentrating element further comprises a filling body filled on a concave surface of the plurality of concentric annular bodies, the filling body making the plurality of The top surface of the concentric annular body is flat and parallel to the bottom surface, and the refractive index of the filling body is the same everywhere.

The high transmission antenna according to claim 16, wherein the filler has a refractive index of n _{n or} less.

The high transmission antenna according to claim 16, wherein the filling body has a refractive index of 1.