WO2023248881A1

WO2023248881A1 - Radio wave relay

Info

Publication number: WO2023248881A1
Application number: PCT/JP2023/022022
Authority: WO
Inventors: 遼上杉; 裕太岡西; 隆史西宮; 芳雄青木; 恭白方
Original assignee: 日本電気硝子株式会社; 株式会社ヨコオ
Priority date: 2022-06-22
Filing date: 2023-06-14
Publication date: 2023-12-28

Abstract

The present invention facilitates relaying while accurately maintaining a plurality of polarized waves. This radio wave relay comprises: a waveguide (1) having a circular or square cross-sectional surface; a first horn (2) provided to one end (1a) of the waveguide (1); and a first radio wave lens (3) which is provided to an opening (2a) of the first horn (2), causes a radio wave (7), including at least one among a microwave and a millimeter wave which are incident to the first radio wave lens, to converge and pass therethrough, and guides the radio wave (7) to the waveguide (1).

Description

radio repeater

The present disclosure relates to a radio wave repeater.

In recent years, consumer equipment that uses high frequencies in the microwave and millimeter wave bands has rapidly become popular due to the demand for higher resolution radars and sensors, and high-capacity, high-speed communications represented by fifth-generation mobile communication systems. . However, because high-frequency radio waves are difficult to diffract, it is difficult for radio waves to reach behind objects that are shielded, leading to concerns that this may cause problems with high-speed communications.

In addition, current microwave/millimeter wave communication uses multiple antennas on both the transmitting and receiving sides using MIMO (Multiple-Input/Multiple-Output) technology to achieve high throughput and highly reliable communication. Since line-of-sight communication is a prerequisite for millimeter waves, normal MIMO cannot be used, so polarized MIMO technology is used that creates multiple paths using multiple polarized waves.

Patent Document 1 discloses a repeater that relays microwaves from a base station and includes a high-gain antenna, a transmission line, and a low-gain antenna.

Japanese Patent Publication “Unexamined Patent Publication No. 8-84106”

In the technology disclosed in Patent Document 1, it is shown that the relay distance can be extended by increasing the gain of the base station side antenna of the repeater, but it is possible to extend the relay distance by increasing the gain of the antenna on the base station side of the repeater. No consideration is given to relaying the data while maintaining accuracy.

A radio wave repeater according to an aspect of the present disclosure includes a waveguide having a circular or square cross section, a first horn provided at one end of the waveguide, and an opening of the first horn. , a first radio wave lens that converges and transmits radio waves including at least one of microwaves and millimeter waves incident thereon and guides them to the waveguide.

According to one aspect of the present disclosure, it is easy to relay multiple polarized waves while accurately maintaining them.

FIG. 1 is a schematic diagram of a radio repeater according to Embodiment 1 of the present disclosure. FIG. 3 is a diagram illustrating the transmission of radio waves through a radio lens with respect to the dielectric loss tangent of the radio lens. FIG. 2 is a cross-sectional view showing a schematic configuration of a radio wave dielectric component according to Embodiment 2 of the present disclosure. It is an explanatory diagram of εc, ε1, ε2, ε3, ε4, tc, t1, t2, t3, and t4. It is a graph showing simulation results of reflection and transmission characteristics of ceramics (thickness 10 mm) with a dielectric constant of 12. It is a graph showing the reflection and transmission characteristics of PTFE (thickness 3.3 mm) in the case of vertical incidence of radio waves. It is a graph showing the reflection and transmission characteristics of a glass plate having a dielectric constant of 5 and a thickness of 10 mm. 8 is a graph showing reflection and transmission characteristics of the glass plate of FIG. 7 with PTFE (relative dielectric constant εr=2.3, thickness 1.65 mm (corresponding to λa/4)) attached to both sides. It is a graph showing the characteristics of two layers of only the first coat layer. It is a graph showing the characteristics when the first coat layer and the second coat layer are stacked and there is no core material. 1 is a graph showing reflection and transmission characteristics of a member including a first coat layer, a second coat layer, and a core material. 10 is a graph showing reflection and transmission characteristics in the case of vertical incidence of radio waves when the thickness of the first coat layer is 1 mm with respect to the characteristics shown in FIG. 9. It is a graph showing the characteristics when a second coat layer and a first coat layer having a thickness of 1 mm are stacked. It is a graph showing reflection and transmission characteristics in the case of vertical incidence of radio waves when the first coat layer (relative dielectric constant 6.0, thickness 1.02 mm) is two layers. 15 is a graph showing reflection and transmission characteristics in the case of vertical incidence of radio waves when a second coat layer is stacked on the first coat layer according to FIG. 14. FIG. 16 is a graph showing reflection and transmission characteristics in the case of vertical incidence of radio waves when the core material is sandwiched between the coating layers according to FIG. 15. FIG. It is a graph showing the reflection and transmission characteristics in the case of vertical incidence of radio waves when the first coat layer (relative dielectric constant 10.8, thickness 0.77 mm) is two layers. 18 is a graph showing reflection and transmission characteristics in the case of vertical incidence of radio waves when a second coat layer is stacked on the first coat layer according to FIG. 17. FIG. 19 is a graph showing reflection and transmission characteristics in the case of vertical incidence of radio waves when the core material is sandwiched between the coating layers according to FIG. 18. FIG. 3 is a graph showing reflection and transmission spectra. 3 is a graph showing reflection and transmission spectra. 1 is a reflection and transmission spectrum of a combination of a first coat layer and a second coat layer according to Example 1. 2 is a reflection and transmission spectrum of a radio wave dielectric component according to Example 1. 2 is a reflection and transmission spectrum of a combination of a first coat layer and a second coat layer according to Example 2. 3 is a reflection and transmission spectrum of a combination of a first coat layer and a second coat layer according to Example 3. 3 is a reflection and transmission spectrum of a dielectric component for radio waves according to Example 3. 3 is a reflection and transmission spectrum of a combination of a first coat layer and a second coat layer according to Example 4. 3 is a reflection and transmission spectrum of a dielectric component for radio waves according to Example 4. FIG. 2 is a schematic diagram of a fan beam lens. 30 is a sectional view taken along line AA of the fan beam lens shown in FIG. 29. FIG. 30 is a cross-sectional view taken along line BB of the fan beam lens shown in FIG. 29. FIG. FIG. 3 is a schematic diagram of a radio wave repeater according to Embodiment 3 of the present disclosure. FIG. 2 is a schematic diagram of a reflector.

A mode for implementing the present disclosure will be described. For convenience of explanation, members having the same functions as previously described members are given the same reference numerals, and the description thereof may not be repeated.

[Embodiment 1]
FIG. 1 is a schematic diagram of a radio repeater 101 according to Embodiment 1 of the present disclosure. The radio wave repeater 101 includes a waveguide 1, a first horn 2, a first radio lens 3, a second horn 4, and a second radio lens 5.

The base station 6 emits radio waves 7. The radio waves 7 include at least one of microwaves and millimeter waves. The radio wave repeater 101 relays the radio waves 7. By relaying the radio waves 7 by the radio wave repeater 101, communication using the radio waves 7 is possible between the base station 6 and the terminal 9, which are separated from each other by a shield 8 such as a wall or window.

Furthermore, the radio wave repeater 101 according to Embodiment 1 of the present disclosure also has a function of bending the radio waves 7. Therefore, even if the terminal 9 is placed in a non-line-of-sight (NLOS) location with respect to the base station 6, the radio waves 7 can be communicated without being blocked.

The waveguide 1 is provided in a through hole 8a formed in the shield 8. The waveguide 1 has a circular or square cross section. Thereby, the polarization information of the radio wave 7 incident from one end 1a of the waveguide 1 can be maintained and the radio wave 7 can be emitted to the other end 1b of the waveguide 1. The first horn 2 is provided at one end 1a of the waveguide 1. The first horn 2 is provided so that the opening 2a of the first horn 2 faces the direction in which the radio waves 7 are incident. The first radio lens 3 is provided in the opening 2a of the first horn 2. The first radio wave lens 3 converges and transmits the radio waves 7 that have entered the first radio wave lens 3 itself, and guides them to the waveguide 1 .

The second horn 4 is provided at the other end 1b of the waveguide 1. The second horn 4 is provided such that the opening 4a of the second horn 4 faces the terminal 9. The second radio wave lens 5 is provided in the opening 4a of the second horn 4. The second radio wave lens 5 converges and transmits the radio waves 7 that have passed through the waveguide 1.

By using the first radio wave lens 3, the effect of increasing the gain can be obtained even if the size of the first horn 2 is reduced. Thereby, it is possible to provide the radio wave repeater 101 that is not noticeable even when installed on a wall.

By using the second radio wave lens 5, the radio waves 7 can be uniformly propagated from the radio wave repeater 101 into the area where the plurality of terminals 9 are placed. According to the radio wave repeater 101, it is easy to relay a plurality of polarized waves while maintaining them accurately. Moreover, depending on the selection of the material, shape, etc. of the second radio wave lens 5, the radio wave repeater 101 can emit the radio waves 7 over a wide range or a long distance.

The waveguide 1 may be a waveguide. Thereby, loss of the radio waves 7 passing through the waveguide 1 can be suppressed.

The waveguide 1 may be a flexible waveguide. Thereby, the direction of the first horn 2 can be freely changed, for example, the direction with respect to the base station 6 can be easily changed, and the directional gain of the first radio wave lens 3 can be utilized to the maximum. Can be done. An example of "flexibility" is the ability to bend when an external force is applied and return to its original shape when the external force is removed.

The waveguide 1 may be a curved waveguide. Thereby, the direction of the first horn 2 can be freely changed, for example, the direction with respect to the base station 6 can be easily changed, and the directional gain of the first radio lens 3 can be utilized to the maximum. Can be done.

It is preferable that the directivity gain of the first radio wave lens 3 is high. By increasing the height, radio waves from the base station 6 can be received more strongly, and communication quality can be improved. The directivity gain of the first radio wave lens 3 is preferably 10 dBi or more, more preferably 15 dBi or more, even more preferably 20 dBi or more, even more preferably 25 dBi or more, and even more preferably 30 dBi or more.

The directional gain of the first radio wave lens 3 may be 10 dBi or more. The first radio wave lens 3 may have a core material made of glass, glass ceramics, or ceramics. The dielectric loss tangent of the first radio wave lens 3 may be 10 ⁻² or less.

FIG. 2 is a diagram showing an image of transmission of the radio wave 7 through the radio wave lens 10 with respect to the dielectric loss tangent of the radio wave lens 10. The radio lens 10 refers to either the first radio lens 3 or the second radio lens 5.

The directional gain of the radio wave lens 10 may be 10 dBi or more, 15 dBi or more, 20 dBi or more, 25 dBi or more, or 30 dBi or more. When the radio wave lens 10 has a high directivity gain, radio waves from the base station 6 can be received more strongly, and communication quality can be improved. On the other hand, when it is desired to propagate the radio waves 7 over a wide range, the directional gain of the radio lens 10 may be 30 dBi or less, 25 dBi or less, 20 dBi or less, or 15 dBi or less. It may be 10 dBi or less.

The dielectric loss tangent of the radio wave lens 10 may be 10 ⁻² or less, 10 ⁻³ or less, or 10 ⁻⁴ or less. When the dielectric loss tangent of the radio wave lens 10 is small, power loss inside the radio wave lens 10 becomes small. If the dielectric loss tangent of the radio wave lens 10 is large, the loss becomes large, which may adversely affect communication between the base station 6 and the terminal 9 using the radio waves 7.

The relative dielectric constant of the radio wave lens 10 may be 4 or more, 7 or more, 10 or more, or 13 or more. When the relative dielectric constant of the radio wave lens 10 is high, the ability to refract the radio waves 7 becomes high, the radio waves can be largely refracted with a low lens height, and the thickness of the radio wave lens 10 and the horn can be made thin.

The radio wave lens 10 has a dielectric material, and may absorb and scatter the radio waves 7 inside the dielectric material.

In the distribution of relative dielectric constant within the radio wave lens 10, the difference between the maximum value and the minimum value may be 0.1 or less. This increases the gain in the radio wave repeater 101.

When the radio wave lens 10 has a core material made of glass, glass ceramics, or ceramics, during the manufacture of the radio wave lens 10, the heating rate of the atmosphere when heating the material of the radio wave lens 10 is slowed, The shrinkage time associated with sintering of the material may be lengthened. These may be performed in accordance with the crystallization temperature range of the material. Thereby, a radio wave lens 10 can be obtained in which the difference between the maximum value and the minimum value of the density (in other words, relative dielectric constant) of the material within the radio wave lens 10 is small. The temperature increase rate may be set such that the difference between the maximum value and the minimum value of the temperature distribution within the material is 0.5° C. or less. The temperature increase rate may be 10° C. or less per hour.

The radio wave repeater 101 does not require a power source. Therefore, the radio wave repeater 101 has a high degree of freedom in installation, that is, it can be installed in more locations. Further, by using an inorganic dielectric material for the radio wave lens 10, deterioration in the outside environment can be reduced, and maintainability can be improved.

The radio wave repeater 101 does not need to include the second radio lens 5. Thereby, only the second horn 4 is on the indoor side, and radio waves can be emitted over a wider range.

FIG. 29 is a schematic diagram of the fan beam lens 27. FIG. 30 is a cross-sectional view of the fan beam lens 27 taken along the line AA. FIG. 31 is a BB cross-sectional view of the fan beam lens 27. The fan beam lens 27 can be used as the second radio wave lens 5. FIG. 29 includes an illustration of mainly the front surface of the fan beam lens 27, designated by the reference numeral 1001, and an illustration of the back surface of the fan beam lens 27, designated by the reference numeral 1002.

The fan beam lens 27 is a lens that narrows down radio waves in the direction perpendicular to the ground and emits radio waves over a wide range in the horizontal direction. This suppresses the radiation of radio waves near the ceiling and the ground where they are not needed, and allows the radio waves to be radiated over a wide range in the horizontal direction where they are needed. By suppressing radiation in the vertical direction, gain in the horizontal direction is improved.

In the fan beam lens 27, in a vertical cross section passing through the center of the lens corresponding to the AA cross section, the thickness of the lens becomes thinner from the center to the ends. Thereby, in the vertical direction, the radio waves passing through the lens are bent inward as the radio waves pass through the edges, so that the radiation of the radio waves can be narrowed down. On the other hand, in the fan beam lens 27, the thickness of the lens is constant from the center to the end in a horizontal section passing through the center of the lens corresponding to the BB section. Thereby, in the horizontal direction, the radio waves pass through the lens without being bent, so that the radio waves can be spread over a wide range.

[Embodiment 2]
(Characteristic configuration)
FIG. 3 is a cross-sectional view showing a schematic configuration of a radio wave dielectric component 102 according to Embodiment 2 of the present disclosure. The radio wave dielectric component 102 can be suitably used as a radio wave lens, and in particular can be used as a radio wave lens 10 of the radio wave repeater 101 (more specifically, either the first radio wave lens 3 or the second radio wave lens 5). ) can be suitably used. The usage example of the radio wave dielectric component 102 is not limited to this. An example of the use of the radio wave dielectric component 102 other than a radio wave lens is a member that allows radio waves 25 to pass through, such as a window. The radio wave dielectric component 102 includes a core material 21, a first coat layer 22, and a second coat layer 23.

The antenna 24 emits radio waves 25. The radio waves 25 include at least one of microwaves and millimeter waves. The radio wave dielectric component 102 transmits the radio waves 25 and guides them to the radio wave receiving target 26 .

The core material 21 is made of a dielectric material. The core material 21 has a first surface 21a and a second surface 21b. The first surface 21a and the second surface 21b face each other.

The first coat layer 22 includes a first region 22a and a third region 22b. The first region 22a is provided on the first surface 21a. The third region 22b is provided on the second surface 21b.

In this embodiment, it is assumed that the core material 21 is at the lowest position, and the farther from the core material 21 along the normal direction of the surface of the core material 21, the higher the position is.

The second coat layer 23 includes a second region 23a and a fourth region 23b. The second region 23a is provided on the first region 22a. The fourth region 23b is provided above the third region 22b.

FIG. 4 is an explanatory diagram of εc, ε1, ε2, ε3, ε4, tc, t1, t2, t3, and t4. tc is the thickness of the core material 21.

The dielectric constant of the core material 21 is εc, the dielectric constant of the first region 22a is ε1, the dielectric constant of the second region 23a is ε2, the thickness of the first region 22a is t1, and the dielectric constant of the second region 23a is ε2. Let the thickness be t2. The transmission center wavelength of the radio wave dielectric component 102 is assumed to be λ. At this time, the radio wave dielectric component 102 satisfies Equation (1), Equation (2), and Equation (3). The notation "√ (number)" means the square root of the number in parentheses.

ε2<ε1<εc...(1)
0.9×λ/4≦√(ε1)×t1≦1.1×λ/4 (2)
0.9×λ/4≦√(ε2)×t2≦1.1×λ/4 (3)
The transmission center wavelength of the dielectric component 102 for radio waves is the center wavelength of the wavelength range of the radio waves 25 that can be transmitted through the dielectric component 102 for radio waves. The maximum wavelength value of the range + the minimum wavelength value of the transmittable wavelength range in the radio wave dielectric component 102). The wavelengths mentioned here are all wavelengths in vacuum.

According to the dielectric component 102 for radio waves, even if the dielectric constant of the dielectric component 102 for radio waves is high, the amount of reflection of the radio waves 25 in the dielectric component 102 for radio waves is small. can be led to high efficiency. Furthermore, since the amount of reflection is small, side lobes are small and ghosts are less likely to occur.

The dielectric constant of the third region 22b is ε3, the dielectric constant of the fourth region 23b is ε4, the thickness of the third region 22b is t3, and the thickness of the fourth region 23b is t4. At this time, the radio wave dielectric component 102 may satisfy Formula (4), Formula (5), and Formula (6).

ε4<ε3<εc...(4)
0.9×λ/4≦√(ε3)×t3≦1.1×λ/4 (5)
0.9×λ/4≦√(ε4)×t4≦1.1×λ/4 (6)
The value of ε1 and the value of ε3 may be the same. The value of ε2 and the value of ε4 may be the same. The value of t1 and the value of t3 may be the same. The value of t2 and the value of t4 may be the same. All of these may be satisfied.

In the first coat layer 22, the first region 22a and the third region 22b may have the same dielectric constant, the same thickness, or both. In the second coat layer 23, the second region 23a and the fourth region 23b may have the same dielectric constant, the same thickness, or both.

ε1 may be 0.5 times or more and 0.9 times or less of εc. ε2 may be 3.5 or less.

The values of εc, ε1, ε2, ε3, ε4, tc, t1, t2, t3, and t4 may vary depending on the position within the radio wave dielectric component 102. Each of εc, ε1, ε2, ε3, ε4, tc, t1, t2, t3, and t4 may be an average value of values obtained at each of a plurality of positions.

The core material 21 may be a radio wave lens. Core material 21 may be made of glass, glass ceramics, or ceramics. The first coat layer 22 may be made of glass, glass ceramics, or ceramics. The second coat layer 23 may be made of PTFE (polytetrafluoroethylene) or other resin.

The coat layer provided on the core material 21 may consist of two layers, the first coat layer 22 and the second coat layer 23. In other words, the core material 21 may not be coated with any coating other than the first coat layer 22 and the second coat layer 23 .

(Consideration)
In the following explanation, in principle, there is a concept of the first coat layer 22 and the second coat layer 23, but there is no concept of the first region 22a, the second region 23a, the third region 22b, and the fourth region 23b. For the purpose of simplifying the description, ε1 and ε3 are collectively referred to as ε1, ε2 and ε4 are collectively referred to as ε2, t1 and t3 are collectively referred to as t1, and t2 and t4 are collectively referred to as t2.

A specific example will be explained below along with a simulation. The frequency will be 30.0 GHz ± 3 GHz (fractional bandwidth: 20%), keeping in mind the 5G millimeter wave band (27 to 30 GHz) in Japan. This is not intended to limit this disclosure. Rather, by setting the length or thickness as exemplified below to 1/n, it is possible to correspond to the use of the (30×n) GHz band, which is expected to appear in the future.

FIG. 5 is a graph showing simulation results of reflection and transmission characteristics of ceramics (thickness 10 mm) with a dielectric constant of 12. The material itself is assumed to be lossless. Even if the material itself is lossless, the transmission loss can be as high as 5 dB depending on the frequency due to surface reflection. It can be said that surface reflection greatly contributes to the loss.

One of the objects and advantages of the present disclosure is to provide a coating structure that suppresses reflection and reduces transmission loss. As is clear from Snell's law, reflection at a dielectric interface only needs to have a small refractive index ratio. Electromagnetically, the index of refraction is the square root of the dielectric constant, so the lower the dielectric constant (ie, the closer it is to 1), the lower the reflection.

In the case of a single coat layer, the design method is known. As an example, the case of PTFE (relative dielectric constant εr=2.3) is shown. The radio wave is a combination of multiple reflections: reflection at the interface entering the dielectric from the air and reflection at the interface exiting the dielectric layer.

FIG. 6 is a graph showing the reflection and transmission characteristics of PTFE (3.3 mm thick) when the radio wave 25 is vertically incident.

The thickness of 3.3 mm is the thinnest thickness at which the reflection valley reaches the desired 30 GHz. At this thickness, the electrical length of the dielectric multiplied by the wavelength shortening rate √(εr) of radio waves in the dielectric becomes 1/2 of the wavelength of 10 mm at 30 GHz. That is, Equation (7) holds true, where λa is the wavelength in vacuum of the center frequency of the desired frequency band, εr is the dielectric constant, and t is the thickness.

√(εr)×t=λa/2...(7)
FIG. 7 is a graph showing the reflection and transmission characteristics of a glass plate with a dielectric constant of 5 and a thickness of 10 mm. FIG. 8 is a graph showing the reflection and transmission characteristics of the glass plate with PTFE (relative dielectric constant εr=2.3, thickness 1.65 mm (corresponding to λa/4)) attached to both sides.

As shown in FIG. 8, reflection at the desired frequency is suppressed to -20 dB or less. As can be seen by comparing FIG. 8 and FIG. 6, the reflection characteristics shown in FIG. 6 are approximately the envelope of the reflection characteristics shown in FIG.

When the relative dielectric constant of the dielectric material that becomes the core material 21 becomes large, reflection cannot be sufficiently suppressed with one coating layer. Therefore, a coating layer configuration in which two dielectric layers are stacked (that is, a configuration including a first coating layer 22 and a second coating layer 23) is adopted.

The present disclosure provides the relative permittivity and thickness of each of the first coat layer 22 and the second coat layer 23, thereby suppressing reflection of radio waves 25 in a desired frequency band and obtaining good transmission characteristics.

As a specific example, the first coat layer 22 and second coat layer 23 that suppress reflection in the core material 21 will be described using a core material 21 made of ceramics (thickness 10 mm) with a dielectric constant of 12 shown in FIG.

The constituent requirements of each of the first coat layer 22 and the second coat layer 23 can be summarized as shown in formulas (8) to (12).

ε2<ε1<εc...(8)
√(ε1)×t1=λ/4...(9)
√(ε2)×t2=λ/4...(10)
0.5×εc≦ε1≦0.9×εc (11)
ε2≦3.5 (12)
The core material 21 has εc=12.0 and tc=12 mm. The first coat layer 22 is made of, for example, glass, glass ceramics, or ceramics, and has a value that satisfies Equation (8), Equation (9), and Equation (11). Here, it is assumed that ε1=7.3 and t1=0.92 mm. As the second coat layer 23, a material with a small dielectric constant is used, and here PTFE is used. Here, it is assumed that ε2=2.3 and t2=1.65 mm.

FIG. 6 shows the characteristics when only the second coat layer 23 is stacked in two layers. FIG. 9 shows the characteristics when only two first coat layers 22 are stacked. FIG. 10 shows the characteristics when the first coat layer 22 and the second coat layer 23 are stacked and there is no core material 21. The reflection and transmission characteristics of the member including the first coat layer 22, the second coat layer 23, and the core material 21 are shown in FIG.

The reflection characteristics shown in FIG. 10 are approximately the envelope of the entire reflection characteristics including the core material 21, and have low reflection and low loss at a fractional bandwidth of 20% centered on the desired frequency (30 GHz). By bonding the first coat layer 22 and second coat layer 23 shown in FIG. 10 to the core material 21 having the reflection-transmission characteristics shown in FIG. 5, the transmission characteristics are significantly improved as shown in FIG. 11.

The following four points are listed as key points of the present disclosure.

Equation (8): The relative permittivity of the first coat layer 22 and the second coat layer 23 is increased from the outside toward the inside. By reducing the difference in dielectric constant at the interface between each dielectric layer, overall reflection is suppressed.

Equations (9) and (10)...The electrical length of each of the first coat layer 22 and the second coat layer 23 is set to 1/4 wavelength of the center frequency of the desired frequency band. The frequencies at which the respective reflections of the first coat layer 22 and the second coat layer 23 are minimized are matched.

Equation (11) defines the dielectric constant of the first coat layer 22. Due to reflection at the interface between the first coat layer 22 and the second coat layer 23, two reflection minima appear above and below the desired center frequency. The frequency of this sideband low reflection is determined by the dielectric constant. In order to obtain the practically required bandwidth and reflection amount, it is within the range of Equation (11).

Equation (12) defines the dielectric constant of the second coat layer 23. This is a practical condition that a practical low dielectric constant material has a dielectric constant of approximately 3.5 or less.

The essence of the present disclosure can be explained as follows.

- Each of the first coat layer 22 and the second coat layer 23 has a dielectric constant and a thickness that minimize reflection at a desired frequency.

- Even the layer obtained by laminating the first coat layer 22 and the second coat layer 23 has the same reflection minimum value.

- When the first coat layer 22 and the second coat layer 23 are bonded together, a minimum reflection value appears due to multiple reflections at these interfaces. As in the case of frequency mixing, two minimum values appear: a lower minimum value and an upper minimum value.

・The frequencies of the two sideband minimum values are determined by the dielectric constant.

- Since each of the first coat layer 22 and the second coat layer 23 has a lower dielectric constant than the core material 21, the reflection characteristics of the first coat layer 22 and the second coat layer 23 become an envelope, and the reflection characteristics of the core material 21 Reflection characteristics are superimposed.

Mathematically speaking, it is similar to a frequency converter or a mixer in communications etc., and the present disclosure mixes the low reflection extremes of the first coat layer 22 and the second coat layer 23. This makes the side band low reflection extreme value appear and widens the low reflection frequency band.

The present disclosure provides a broadband low-reflection coating layer by mixing reflected waves between the first coating layer 22 and the second coating layer 23, and uses a novel idea of mixing reflected waves. There is.

The present disclosure is generally used when the core material 21 is a high dielectric material with a dielectric constant of 6 or more. Although the dielectric constant may be less than 6, the effect is not much different from that of a single layer coating. Practically, it is effective to use it for glass, ceramics (including LTCC and HTCC), etc., which have a dielectric constant of 8 or more.

Even when three or more coat layers are stacked, the technique of mixing reflection between coat layers, which the present disclosure is based on, can be applied. However, since the degree of freedom in design increases by the combination of layers, its application is not practical.

By attaching the first coat layer 22 and the second coat layer 23 of the present disclosure to a plate material such as glass or ceramics having a relatively high dielectric constant, reflection can be suppressed and the transmission characteristics of the radio waves 25 can be improved. can. It can be applied to windows or walls of houses. Further, by bonding the first coat layer 22 and the second coat layer 23 of the present disclosure on both sides of the core material 21, the directivity gain of the radio wave dielectric component 102 as a radio wave lens can be increased.

FIG. 12 shows the reflection and transmission characteristics when the radio wave 25 is vertically incident when the thickness t1 of the first coat layer 22 is increased from 0.92 mm to 1 mm (approximately 10% increase) with respect to the characteristics shown in FIG. 9. . The frequency at which low reflection occurs is shifted to the lower frequency side by approximately 10%, and low reflection occurs at 27 GHz.

FIG. 13 shows the characteristics when the second coat layer 23 and the first coat layer 22 having a thickness t1 of 1 mm are stacked. This characteristic is caused by the fact that the characteristic shown in FIG. 10 is broken down because the thickness of the first coat layer 22 is 10% larger. Because the low reflection valley on the side has shifted to the lower frequency side, the 30 GHz valley and 37 GHz valley in Figure 10 are combined into the 33 GHz valley in Figure 13, and the valley that was at 23 GHz in Figure 10 has shifted to 21 GHz, and the 37 GHz valley in Figure 10 has shifted to 25 GHz. The peak of is getting bigger and is below -20dB. This is one basis for the limit value of the present disclosure. When the first coat layer 22 becomes thinner, the frequency shifts to the higher frequency side, but the situation remains the same.

Assuming that ε2=2.3, t2=1.65 mm, εc=12.0, and tc=10 mm, the limit value of ε1 will be described. Two cases are shown: ε1=6 (0.5×εc) and ε1=10.8 (0.9×εc).

- In the case of ε1=6 (0.5×εc) From equation (9), the thickness t1 of the first coat layer 22 is 1.02 mm. This characteristic is as shown in FIG. When the second coat layer 23 is superimposed on the first coat layer 22, the characteristics shown in FIG. 15 are obtained. The reflection will be greater than -20dB.

The characteristics of the core material 21 sandwiched between the coat layers (first coat layer 22 and second coat layer 23) according to FIG. 15 are shown in FIG. Reflection at 30GHz exceeds -20dB.

- In the case of ε1=10.8 (0.9×εc) From equation (9), the thickness t1 of the first coat layer 22 is 0.77 mm. This characteristic is as shown in FIG. When the second coat layer 23 is superimposed on the first coat layer 22, the characteristics shown in FIG. 18 are obtained.

The characteristics of the core material 21 sandwiched between the coat layers (first coat layer 22 and second coat layer 23) according to FIG. 18 are shown in FIG. Using the first coat layer 22 and the second coat layer 23, the point of the present disclosure is to create a sideband of the reflection valley, which is the limit state. The reflection at the desired frequency is about -10 dB. This is the practical limit.

FIG. 20 is a graph showing reflection and transmission spectra under the following conditions.

・Core material 21: εc=12.0, tc=12mm
・First coat layer 22: ε1=7.3, t1=1.1mm
・Second coat layer 23: ε2=2.3, t2=1.65mm
・Transmission center wavelength: λ = 10mm (equivalent to frequency: 30GHz)
FIG. 21 is a graph showing reflection and transmission spectra under the following conditions.

・Core material 21: εc=12.0, tc=12mm
・First coat layer 22: ε1=7.3, t1=0.74mm
・Second coat layer 23: ε2=2.3, t2=1.65mm
・Transmission center wavelength: λ = 10mm (equivalent to frequency: 30GHz)
It can be said that the characteristics shown in FIGS. 20 and 21 are each worse than the characteristics shown in FIG. 11.

(Example)
FIG. 22 shows reflection and transmission spectra of the combination of the first coat layer 22 and the second coat layer 23 according to Example 1. FIG. 23 shows reflection and transmission spectra of the radio wave dielectric component 102 according to Example 1.

FIG. 24 shows the reflection and transmission spectra of the combination of the first coat layer 22 and the second coat layer 23 according to Example 2.

FIG. 25 shows the reflection and transmission spectra of the combination of the first coat layer 22 and the second coat layer 23 according to Example 3. FIG. 26 shows reflection and transmission spectra of the radio wave dielectric component 102 according to Example 3.

FIG. 27 shows the reflection and transmission spectra of the combination of the first coat layer 22 and the second coat layer 23 according to Example 4. FIG. 28 shows reflection and transmission spectra of the radio wave dielectric component 102 according to Example 4.

In Examples 1 to 4, εc, ε1, ε2, tc, t1, t2, and λ are as follows.

εc=12.0
ε1=7.3 (Examples 1 and 2), 6.0 (Example 3), 10.8 (Example 4)
ε2=2.3
tc=12mm
t1=0.92mm (Example 1), 1mm (Example 2), 1.02mm (Example 3), 0.77mm (Example 4)
t2=1.65mm
λ=10mm (equivalent to frequency: 30GHz)
According to Example 1, reflection is suppressed to -20 dB or less over a wide band centered on the target wavelength (here, 30 GHz).

According to Example 2, at the upper limit of the range defined by Equation (2), the band in which reflection is suppressed is narrower than in Example 1, but is still sufficiently wide.

According to Example 3, when ε1=6.0 (0.5×εc), the suppressed reflection intensity is smaller than in Example 1, but is still sufficiently large.

According to Example 4, when ε1=10.8 (0.9×εc), the band in which reflection is suppressed is narrower than in Example 1, but is still sufficiently wide. According to Example 4, when ε1=10.8 (0.9×εc), the suppressed reflection intensity is smaller than in Example 1, but is still sufficiently large.

[Embodiment 3]
FIG. 32 is a schematic diagram of a radio repeater 101 according to Embodiment 3 of the present disclosure. FIG. 33 is a schematic diagram of reflector 28. A radio wave repeater 101 according to Embodiment 3 of the present disclosure includes a waveguide 1 having a circular or square cross section and a reflector 28 provided at one end of the waveguide 1. It includes a reflector 28 that reflects and converges the radio waves 7 containing at least one of the millimeter waves and guides them to the waveguide 1. The reflector 28 has a main reflecting mirror 29, a sub-reflecting mirror 30, and a third horn 31.

The main reflecting mirror 29 has a parabolic surface, and the sub-reflecting mirror 30 has an ellipsoidal surface. These curved surfaces can reduce the phase difference of radio waves at the focal point and increase the gain.

The reflector 28 is used in place of the first horn 2 and first radio lens 3 in the radio wave repeater 101 according to the first embodiment of the present disclosure. The third horn 31 and the waveguide 1 are connected to form a radio wave repeater 101 according to the third embodiment of the present disclosure.

The reflector 28 reflects the radio waves 7 from the base station 6 on the main reflector 29, converges the radio waves 7 on the sub-reflector 30, further reflects the radio waves 7 on the sub-reflector 30, and focuses the radio waves 7 on the center of the main reflector 29. The radio waves 7 are converged on the third horn 31 located at the third horn 31, and the radio waves 7 are relayed.

The larger the diameter of the main reflecting mirror 29, the higher the gain can be. Since the main reflecting mirror 29 is a metal plate with a curved surface, it is easy to manufacture it with a large diameter. The reflector 28 can be utilized when it is difficult to fabricate a large lens using a dielectric material.

(summary)
A radio wave repeater according to aspect 1 of the present disclosure includes a waveguide having a circular or square cross section, a first horn provided at one end of the waveguide, and an opening of the first horn. , a first radio wave lens that converges and transmits radio waves including at least one of microwaves and millimeter waves incident thereon and guides them to the waveguide.

A radio wave repeater according to Aspect 2 of the present disclosure is provided in Aspect 1, including a second horn provided at the other end of the waveguide and an opening of the second horn, so that the waveguide passes through the waveguide. and a second radio wave lens that converges and transmits the radio waves.

In the radio wave repeater according to Aspect 3 of the present disclosure, in

Aspect

1 or 2, the first radio wave lens has a core material made of glass, glass ceramics, or ceramics.

In the radio wave repeater according to aspect 4 of the present disclosure, in any one of aspects 1 to 3, the dielectric loss tangent of the first radio wave lens is 10 ⁻² or less.

In the radio wave repeater according to aspect 5 of the present disclosure, in any one of aspects 1 to 4, the relative dielectric constant of the first radio wave lens is 7 or more.

In the radio wave repeater according to aspect 6 of the present disclosure, in any one of aspects 1 to 5, the waveguide is a flexible waveguide.

In the radio wave repeater according to aspect 7 of the present disclosure, in any one of aspects 1 to 6, the waveguide is a curved waveguide.

In the radio wave repeater according to Aspect 8 of the present disclosure, in Aspect 2, the second radio wave lens is a fan beam lens.

A radio wave repeater according to aspect 9 of the present disclosure includes a waveguide having a circular or square cross section, and a reflector provided at one end of the waveguide, and includes at least a microwave and a millimeter wave incident on the radio wave repeater. and a reflector that reflects and converges the radio waves containing one of the waves and guides them to the waveguide.

The present disclosure is not limited to the embodiments described above, and various changes can be made within the scope of the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. are also included within the technical scope of the present disclosure.

1 Waveguide 1a One end of the waveguide 1b The other end of the waveguide 2 First horn 2a Opening of the first horn 3 First radio wave lens 4 Second horn 4a Opening of the second horn 5 Second radio lens 6 Base station 7 Radio wave 8 Shielding object 8a Through hole 9 Terminal 10 Radio wave lens 21 Core material 21a 1st surface 21b 2nd surface 22 1st coat layer 22a 1st region 22b 3rd region 23 2nd coat layer 23a 2nd region 23b 4th region 24 Antenna 25 Radio waves 26 Radio wave reception target 27 Fan beam lens 28 Reflector 29 Main reflector 30 Sub-reflector 31 Third horn 101 Radio wave repeater 102 Dielectric parts for radio waves

Claims

a waveguide with a circular or square cross section;
a first horn provided at one end of the waveguide;
a first radio wave lens provided at the opening of the first horn, which converges and transmits radio waves including at least one of microwaves and millimeter waves incident thereon, and guides them to the waveguide; Yes, there is a radio repeater.
a second horn provided at the other end of the waveguide;
The radio wave repeater according to claim 1, further comprising a second radio wave lens that is provided at an opening of the second horn and that converges and transmits the radio waves that have passed through the waveguide.
The radio wave repeater according to claim 1, wherein the first radio wave lens has a core material made of glass, glass ceramics, or ceramics.
The radio wave repeater according to claim 1, wherein the first radio wave lens has a dielectric loss tangent of 10 −2 or less.
The radio wave repeater according to claim 1, wherein the first radio lens has a dielectric constant of 7 or more.
The radio wave repeater according to claim 1, wherein the waveguide is a flexible waveguide.
The radio wave repeater according to any one of claims 1 to 6, wherein the waveguide is a curved waveguide.
The radio wave repeater according to claim 2, wherein the second radio wave lens is a fan beam lens.
a waveguide with a circular or square cross section;
a reflector provided at one end of the waveguide, the reflector reflects and converges radio waves including at least one of microwaves and millimeter waves incident thereon, and guides the waves to the waveguide. Yes, there is a radio repeater.