JP7593394B2 - Waveguide closing member and waveguide with closing member - Google Patents

Description

The present disclosure relates to a closing member for a waveguide and a waveguide with a closing member.

The next-generation 5G (5th Generation) system, which is a wireless broadband communication system, uses radio waves in the millimeter wave band.

For example, a waveguide is used as a means of transmitting radio waves in the millimeter wave band (Patent Document 1, Patent Document 2).

Japanese Patent Application Publication No. 08-195605 JP 2017-228839 A

When installing a waveguide, it is necessary to adjust its length according to its installation. When cutting the waveguide to adjust its length, it is necessary to process the end of the waveguide. When terminating the waveguide, it is necessary to prevent leakage of radio waves from the end and to ensure the reflection characteristics from the end.

The present disclosure provides a technique for terminating a waveguide without compromising the performance of the waveguide.

The present disclosure relates to a conductive waveguide closing member that closes the end of a waveguide having a dielectric layer with a hollow interior and a metal layer covering the outside of the dielectric layer, the waveguide closing member having a flat base portion and a protrusion that protrudes from a main surface of the base portion, the protrusion being inserted into the hollow interior from the end portion and attached to the waveguide.

The present disclosure provides a technology for terminating a waveguide without compromising the performance of the waveguide.

FIG. 2 is a perspective view showing a state in which the closing member of the first embodiment is attached to a waveguide. FIG. 2 is a perspective view showing a state before the closing member of the first embodiment is attached to the waveguide. FIG. 2 is a partial perspective view of a waveguide to which the closing member of the first embodiment is attached. FIG. 2 is a perspective view of the closing member of the first embodiment; FIG. 2 is a cross-sectional view of the closing member of the first embodiment attached to a waveguide. FIG. 10 is a perspective view of a closing member according to a second embodiment; FIG. 11 is a cross-sectional view of a closing member according to a second embodiment attached to a waveguide. FIG. 13 is a perspective view of a closing member according to a third embodiment; FIG. 11 is a cross-sectional view of a closing member according to a third embodiment attached to a waveguide. FIG. 13 is a perspective view of a closing member according to a fourth embodiment; FIG. 10 is a cross-sectional view of a closing member according to a fourth embodiment attached to a waveguide. 13A-13C are diagrams illustrating the reflective properties of a closing member according to an embodiment of the present disclosure. 11A and 11B are diagrams illustrating the reflection characteristics of a closing member of a reference example.

Below, the form for implementing the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding components are given the same or corresponding reference numerals, and duplicate explanations may be omitted. For ease of understanding, the scale of each part in the drawings may differ from the actual scale. In directions such as parallel, right angle, orthogonal, horizontal, vertical, up and down, left and right, deviations are permitted to the extent that do not impair the effect of the embodiment. The shape of the corners is not limited to right angles, and may be rounded in a bow shape. Parallel, right angle, orthogonal, horizontal, and vertical may include approximately parallel, approximately right angle, approximately orthogonal, approximately horizontal, and approximately vertical.

First Embodiment
<Closing member 10>
The closing member 10 of the first embodiment is a waveguide closing member that short-circuits an end of a waveguide 20. Fig. 1 is a perspective view showing a state in which the closing member 10 of the first embodiment is attached to the waveguide 20. Fig. 2 is a perspective view showing a state before the closing member 10 of the first embodiment is attached to the waveguide 20. The waveguide 20 in a state in which the closing member 10 is attached is sometimes called a waveguide with a closing member.

For ease of explanation, an XYZ Cartesian coordinate system is set in the figure. For coordinate axes perpendicular to the plane of the drawing, a cross in a circle indicates that the far side relative to the plane of the drawing is positive, and a black circle in a circle indicates that the near side relative to the plane of the drawing is positive. However, this coordinate system is defined for the purpose of explanation and does not limit the position of the closing member or the waveguide. In this disclosure, unless otherwise specified, the Z axis is the extension direction of the waveguide 20, and the X and Y axes are perpendicular to the extension direction of the waveguide 20.

The closing member 10 and the waveguide 20 of the first embodiment are used, for example, when transmitting radio waves in the millimeter wave band used in the next-generation 5G system. For example, the waveguide 20 connects from a base station to an antenna installed in the space where the user is located.

The antenna may be, for example, a patch antenna or a dipole antenna formed of a flexible substrate. When a flexible substrate is used, a microstrip line or a coplanar line may be used as the line, or a substrate integrated waveguide (SIW) may be used. The thickness of the flexible substrate is preferably 0.8 mm or less. By making the flexible substrate thinner, the flexibility of the flexible substrate can be increased. The dielectric of the flexible substrate is formed of a fluorine-based resin, liquid crystal, polyimide, or the like. As the fluorine-based resin, for example, perfluoroalkoxy alkane (PFA (Perfluoroalkoxy alkane)) can be used.

When a flexible substrate is used, an amplifier may be provided on the flexible substrate. The antenna may be, for example, a slot antenna with a slot in a waveguide. In addition, another waveguide may be connected to the end of the waveguide 20. For example, another waveguide may be connected via a flexible substrate.

The band of radio waves transmitted through the waveguide 20 in the first embodiment is, for example, 27.5 GHz to 29 GHz. For example, the center frequency is 28 GHz. This band is divided into 400 MHz bands for use by each operator. Note that the frequency band is not limited to 27.5 GHz to 29 GHz, and may be, for example, a frequency band centered around 26 GHz or 39 GHz. Furthermore, the frequency band is not limited to the millimeter wave band, and may be another frequency band.

The closing member 10 of the first embodiment is fixed to the +Z end of the waveguide 20. The closing member 10 is mechanically and electrically connected to the waveguide 20, for example, by soldering, brazing, applying a conductive paste, etc. Note that the closing member 110 of the second embodiment, the closing member 210 of the third embodiment, and the closing member 310 of the fourth embodiment, which will be described later, are also fixed to the +Z end of the waveguide 20 in the same manner as the closing member 10.

<Waveguide 20>
First, a description will be given of the waveguide 20 to which the closing member 10 is attached. Fig. 3 is a partial perspective view of the waveguide 20 to which the closing member 10 of the first embodiment is attached.

The waveguide 20 is a waveguide that serves as a waveguide through which radio waves in the millimeter wave band propagate. The waveguide 20 is a cylindrical tube that extends in the direction in which the radio waves propagate. In FIG. 3, the direction in which the radio waves propagate is the Z direction. The inside of the waveguide 20 is a cavity 20h. The waveguide 20 has an outer surface 20s1 and an inner surface 20s2. The waveguide 20 has an end face 20e on the +Z side. A closing member 10 is attached to the end face 20e and is covered by the closing member 10.

The waveguide 20 comprises a dielectric tube 21 having a hollow interior and a metal coating 22 that covers the outside of the dielectric tube 21. The cavity of the dielectric tube 21 becomes the cavity 20h of the waveguide 20. Radio waves propagate through the cavity 20h of the waveguide 20 and the dielectric tube 21. The outer surface of the metal coating 22 becomes the outer surface 20s1 of the waveguide 20. The inner surface of the dielectric tube 21 becomes the inner surface 20s2 of the waveguide 20.

[Dielectric tube 21]
The dielectric tube 21 is a member that functions as a transmission path through which radio waves propagate. In the waveguide 20, radio waves propagate through the cavity 20h and the dielectric tube 21.

The dielectric tube 21 is formed of a dielectric material, for example, a fluororesin. Examples of the fluororesin that can be used include polytetrafluoroethylene (PTFE) and perfluoroalkoxyalkane (PFA).

For example, when the frequency band is 28 GHz, the outer diameter of the dielectric tube 21 is 5 mm to 9 mm. It is preferable that the inner diameter of the dielectric tube 21 is 1 mm to 2 mm smaller than the outer diameter. The dimensions of the dielectric tube 21 vary depending on the frequency band propagating through the waveguide 20 and the material of the dielectric.

[Metal Coating 22]
The metal coating 22 is a member that defines the transmission path. The metal coating 22 is formed of a conductive member, for example, copper. The metal coating 22 is formed, for example, by plating. Note that the method of forming the metal coating 22 is not limited to plating, and for example, the metal coating 22 may be formed by winding copper foil or a metal net. Note that an insulating coating may be further provided on the outside of the metal coating 22 of the waveguide 20.

The waveguide 20 is formed of a dielectric tube 21 and a metal coating 22, and has a flexibility of approximately R1000.

Note that the dielectric tube 21 is an example of a dielectric layer, and the metal coating 22 is an example of a metal layer.

<Closing member 10>
Next, the closing member 10 of the first embodiment will be described. Fig. 4 is a perspective view of the closing member 10 of the first embodiment. Fig. 5 is a cross-sectional view of the closing member 10 of the first embodiment attached to the waveguide 20. Specifically, Fig. 5 is a cross-sectional view of the closing member 10 attached to the waveguide 20, cut along a plane perpendicular to the X-axis passing through the center of the waveguide 20.

The closing member 10 of the first embodiment is a member that closes the end of the waveguide 20. The closing member 10 is formed of a conductive material, for example, copper. The closing member 10 has a base portion 10a and a protruding portion 10b. The closing member 10 may be formed by depositing a conductive material such as copper plating on a resin so that only the surface of the closing member 10 is conductive. In other words, the closing member 10 may be formed of a resin with a conductive material deposited on its surface. The same applies to the closing member 110 of the second embodiment, the closing member 210 of the third embodiment, and the closing member 310 of the fourth embodiment, which will be described later.

The base portion 10a is a disk-shaped (flat) member. The surface 10s1 (main surface) of the base portion 10a is a surface that covers the end surface 20e of the waveguide 20 when the closing member 10 is attached to the waveguide 20. In other words, the base portion 10a covers the end surface 20e of the waveguide 20 when the closing member 10 is attached to the waveguide 20.

The protrusion 10b is provided to protrude from the base portion 10a. When the closing member 10 is attached to the waveguide 20, the protrusion 10b is provided inside the cavity 20h of the waveguide 20. The protrusion 10b has a shape that follows the shape of the cavity 20h of the waveguide 20. The surface 10s2 of the protrusion 10b is a reflective surface that reflects radio waves propagating in the +Z direction through the cavity 20h of the waveguide 20 in the -Z direction.

Since the waveguide 20 is formed of a dielectric tube 21, the dielectric tube 21 can change shape as it changes shape. Therefore, when the closure member 10 with the protrusion 10b is inserted into the dielectric tube 21 of the waveguide 20, the dielectric tube 21 made of resin can change shape. Therefore, even if the tolerance of the protrusion 10b increases, it can be absorbed by the deformation of the dielectric tube 21.

The blocking member 10 and the waveguide 20 can be electrically connected by soldering, brazing, adhesive bonding with conductive paste, etc.

The shape of the base portion 10a is not limited to a disk shape. For example, the base portion 10a may be rectangular or have another shape as long as it can cover the end face 20e of the waveguide 20. The shape of the base portion is the same in the embodiments described below.

Second Embodiment
<Closing member 110>
A closing member 110 of the second embodiment will be described. The closing member 110 of the second embodiment is a member that shorts an end of the waveguide 20. Fig. 6 is a perspective view of the closing member 110 of the second embodiment. Fig. 7 is a cross-sectional view of the closing member 110 of the second embodiment attached to the waveguide 20. Specifically, Fig. 7 is a cross-sectional view of the closing member 110 attached to the waveguide 20, cut along a plane perpendicular to the X-axis at the center of the waveguide 20.

The closing member 110 of the second embodiment is a member that closes the end of the waveguide 20. The closing member 110 is formed of a conductive material, for example, copper. The closing member 110 includes a base portion 110a, a protruding portion 110b, and a visor portion 110c.

The base portion 110a is a disk-shaped (flat) member. The surface 110s1 of the base portion 110a is a surface that covers the end surface 20e of the waveguide 20 when the closing member 110 is attached to the waveguide 20. In other words, the base portion 110a covers the end surface 20e of the waveguide 20 when the closing member 110 is attached to the waveguide 20.

The protrusion 110b is provided to protrude from the base portion 110a. When the closing member 110 is attached to the waveguide 20, the protrusion 110b is provided inside the cavity 20h of the waveguide 20. The protrusion 110b has a shape that follows the shape of the cavity 20h of the waveguide 20. The surface 110s2 of the protrusion 110b is a reflective surface that reflects radio waves propagating in the +Z direction through the cavity 20h of the waveguide 20 in the -Z direction.

The eaves portion 110c is provided to protrude from the base portion 110a. The eaves portion 110c is provided so as to be located outside the waveguide 20 when the closing member 110 is attached to the waveguide 20. The eaves portion 110c has a surface 110cs3 at its end in the -Z direction.

The closing member 110 and the waveguide 20 can be electrically connected by soldering, brazing, or bonding with conductive paste. In addition, by providing the eaves portion 110c, the closing member 110 can be electrically connected by crimping it from the outside of the eaves portion 110c, for example.

Third Embodiment
<Closing member 210>
A closing member 210 of the third embodiment will be described. The closing member 210 of the third embodiment is a member that shorts an end of the waveguide 20. Fig. 8 is a perspective view of the closing member 210 of the third embodiment. Fig. 9 is a cross-sectional view of the closing member 210 of the third embodiment attached to the waveguide 20. Specifically, Fig. 9 is a cross-sectional view taken along a plane perpendicular to the X-axis at the center of the waveguide 20 in a state in which the closing member 210 is attached to the waveguide 20.

The closing member 210 of the third embodiment is a member that closes the end of the waveguide 20. The closing member 210 is formed of a conductive material, for example, copper. The closing member 210 has a base portion 210a and a protrusion portion 210b.

The base portion 210a is a disk-shaped (flat) member. The surface 210s1 of the base portion 210a is a surface that covers the end surface 20e of the waveguide 20 when the closing member 210 is attached to the waveguide 20. In other words, the base portion 210a covers the end surface 20e of the waveguide 20 when the closing member 210 is attached to the waveguide 20.

The protrusion 210b is provided protruding from the base portion 210a. When the closing member 210 is attached to the waveguide 20, the protrusion 210b is provided inside the cavity 20h of the waveguide 20. The protrusion 210b has a shape that follows the shape of the cavity 20h of the waveguide 20. The protrusion 210b is a truncated cone shape that is thick on the base portion 210a side (+Z side) and thin on the opposite side of the base portion 210a (-Z side). The surface 210s2 of the protrusion 210b is a reflective surface that reflects radio waves propagating in the +Z direction through the cavity 20h of the waveguide 20 in the -Z direction.

By forming the protrusion 210b in a truncated cone shape, the dielectric tube 21 has the property of bending and collapsing, so that it is possible to improve both the physical and electrical reliability of the connection between the closing member 210 and the waveguide 20. The diameter of the protrusion 210b may be made larger than the cavity 20h of the waveguide 20 and press-fitted.

The closing member 210 and the waveguide 20 can be electrically connected by soldering, brazing, or bonding with conductive paste.

Fourth Embodiment
<Closing member 310>
A closing member 310 of the fourth embodiment will be described. The closing member 310 of the fourth embodiment is a member that shorts an end of the waveguide 20. Fig. 10 is a perspective view of the closing member 310 of the fourth embodiment. Fig. 11 is a cross-sectional view of the closing member 310 of the fourth embodiment attached to the waveguide 20. Specifically, Fig. 11 is a cross-sectional view taken along a plane perpendicular to the X-axis at the center of the waveguide 20 in a state in which the closing member 310 is attached to the waveguide 20.

The closing member 310 of the fourth embodiment is a member that closes the end of the waveguide 20. The closing member 310 is formed of a conductive material, for example, copper. The closing member 310 includes a base portion 310a, a protruding portion 310b, and a visor portion 310c.

The base portion 310a is a disk-shaped (flat) member. The surface 310s1 of the base portion 310a is a surface that covers the end surface 20e of the waveguide 20 when the closing member 310 is attached to the waveguide 20. In other words, the base portion 310a covers the end surface 20e of the waveguide 20 when the closing member 310 is attached to the waveguide 20.

The protrusion 310b is provided protruding from the base portion 310a. When the closing member 310 is attached to the waveguide 20, the protrusion 310b is provided inside the cavity 20h of the waveguide 20. The protrusion 310b has a shape that follows the shape of the cavity 20h of the waveguide 20. The surface 310s2 of the protrusion 310b is a reflective surface that reflects radio waves propagating in the +Z direction through the cavity 20h of the waveguide 20 in the -Z direction.

The protrusion 31b may be shaped like a truncated cone. By making the protrusion 310b shaped like a truncated cone, the dielectric tube 21 has the property of bending and collapsing, so that the connection reliability between the closing member 210 and the waveguide 20 can be improved both physically and electrically. The diameter of the protrusion 310b may be made larger than the cavity 20h of the waveguide 20 and pressed in.

The eaves portion 310c is provided to protrude from the base portion 310a. The eaves portion 310c is provided so as to be located outside the waveguide 20 when the closing member 110 is attached to the waveguide 20. The eaves portion 310c has a surface 310cs3 at its end in the -Z direction. The eaves portion 310c is thick on the base portion 310a side (+Z side) and thins on the opposite side of the base portion 310a (-Z side). In other words, the tip of the eaves portion 310c is thin. In addition, the inner surface of the eaves portion 310c (waveguide 20 side) is inclined outward toward the -Z side.

By inclining the inner surface of the eaves portion 310c, the dielectric tube 21 has the property of bending and collapsing, so that it is possible to improve both the physical and electrical reliability of the connection between the closing member 310 and the waveguide 20. The inner diameter of the eaves portion 310c may be made smaller than the outer diameter of the waveguide 20 and press-fitted.

The closing member 310 and the waveguide 20 can be electrically connected by soldering, brazing, or bonding with conductive paste. In addition, by providing the eaves portion 310c, the closing member 310 can be electrically connected by crimping it from the outside of the eaves portion 310c, for example.

<Reflection characteristics of the closing member of the embodiment of the present disclosure>

The dimensions of the closing members of the first to fourth embodiments described above were examined from the viewpoint of reflection characteristics. In this study, the closing member 110 of the second embodiment shown in FIG. 7 was examined.

The distance from surface 10s1 to surface 10s2 of the closing member 10 is defined as distance L1. The same applies to the first, third, and fourth embodiments. The distance from surface 110s1 to surface 112s3 of the closing member 110 is defined as distance L2. The same applies to the fourth embodiment.

Most of the radio waves propagating in the +Z direction from the -Z side of the waveguide 20 are reflected by the surface 110s2 and propagate in the -Z direction. On the other hand, some of the radio waves propagate from the outside of the surface 110s2 through the dielectric tube 21 to the surface 110s1, and are reflected by the surface 110s1 and return. It is desirable that the reflected and returned radio waves do not affect the radio waves reflected by the surface 110s2. In other words, the radio waves reflected by the surface 110s2 and the radio waves that pass through the outside of the surface 110s2 and are reflected by the surface 110s1 and return are made to be in phase with each other. Specifically, the distance L1 is made to satisfy the following formula 1. By making the distance L1 satisfy the following formula 1, the phases of the radio waves reflected by the surface 110s2 and the radio waves that pass through the outside of the surface 110s2 and are reflected by the surface 110s1 and return can be made to be in phase with each other.

Here, _λg is the wavelength of the electromagnetic wave propagating through the dielectric tube 21 of the waveguide 20, and n1 is an integer equal to or greater than 0, i.e., a non-negative integer. For example, α1 is 0.35 and α2 is 0.65, preferably α1 is 0.4 and α2 is 0.6, and more preferably α1 is 0.45 and α2 is 0.55. It is preferable that n1 is small.

Next, distance L2 will be considered. Distance L2 will be considered assuming that surface 110s3 is soldered to metal coating 22. In this case, it is desirable to ensure that the radio waves reflected by surface 110s1 and leaking in the direction of surface 110s3 are not affected when they are further reflected by the solder and return. In other words, the radio waves reflected by surface 110s1 and the radio waves leaking from surface 110s1 and reflected by the solder are made to be in phase with each other. Specifically, by satisfying the following formula 2, the phases of the radio waves reflected by surface 110s1 and the radio waves leaking from surface 110s1 and reflected by the solder can be made to be in phase with each other.

Here, λ ₀ is the wavelength of the electromagnetic wave propagating in the air, and n2 is an integer equal to or greater than 0, i.e., a non-negative integer. α3 is 0.35 and α4 is 0.65, preferably, α3 is 0.4 and α4 is 0.6, and more preferably, α3 is 0.45 and α4 is 0.55. It is preferable that n2 is small. Since the cavity 20h of the waveguide 20 can be regarded as air, λ ₀ can be regarded as equal to the wavelength of the electromagnetic wave propagating through the cavity 20h of the waveguide 20.

Here, the results of confirming the effect are shown. FIG. 12 is a diagram for explaining the reflection characteristics of the closing member of the embodiment of the present disclosure. FIG. 13 is a diagram for explaining the reflection characteristics of the closing member of the reference example. The horizontal axis of the reflection intensity and reflection phase graphs in FIG. 12 and FIG. 13 is frequency. The vertical axis of the reflection intensity graphs in FIG. 12 and FIG. 13 represents the ratio of the intensity of the electromagnetic wave reflected and returned by the closing member to the electromagnetic wave incident on the waveguide. Ideally, the reflection intensity is 0 dB. The vertical axis of the reflection phase graphs in FIG. 12 and FIG. 13 represents the change in phase of the electromagnetic wave reflected and returned by the closing member to the electromagnetic wave incident on the waveguide. Here, the phase reference is the surface 110s2 of the closing member 110, and the reflection phase in this case is ideally 180 deg.

The confirmation was carried out by simulation. The dimensions were calculated for α1 and α2 with the frequency of the electromagnetic wave set to 28 GHz. The inner diameter of the dielectric tube 21 was set to 6 mm, and the outer diameter was set to 7 mm. In the simulation, the frequencies between 25 GHz and 31 GHz, including the frequency of 28 GHz, were simulated. The electromagnetic wave propagation mode was the fundamental mode. In the closing member of FIG. 12, α1 and α2 were set to 0.5 for the distance L1 and the distance L2. Specifically, the distance L1 was set to 3.7 mm, and the distance L2 was set to 5 mm. In the closing member of FIG. 13, which is a comparative example, α1 was set to 0.67 for the distance L1, and α2 was set to 0.5 for the distance L2. Specifically, the distance L1 was set to 5.6 mm, and the distance L2 was set to 5 mm. Furthermore, in the simulation, the simulation was carried out for the case where the surface 110s1 and the end surface 20e are in close contact with each other, and the case where the surface 110s1 and the end surface 20e are separated by 0.2 mm. In addition, the solid lines in FIG. 12 and FIG. 13 indicate the case where the electrodes are in close contact, and the dotted lines indicate the case where the electrodes are separated.

In the embodiment of the present disclosure shown in FIG. 12, both the reflection intensity and the reflection phase were almost constant over a wide frequency range. In addition, attenuation at the closing member was suppressed. Furthermore, there was no significant difference regardless of whether the surface 110s1 and the end surface 20e were in close contact or not.

On the other hand, in the reference example of Figure 13, the reflection intensity and reflection phase were both small at a specific frequency. Also, the characteristics differed greatly depending on whether or not the surface 110s1 and the end surface 20e were in close contact with each other.

<Action and Effects>
The waveguide closing member of the present disclosure allows for easy termination of the waveguide. The closing member can be attached to the waveguide 20 by inserting the protruding portion of the closing member into the cavity of the waveguide. The closing member can be electrically connected to the metal coating of the waveguide to short-circuit the waveguide. Furthermore, the closing member can reflect radio waves propagating through the waveguide with reduced attenuation.

<Modification>
The shape of the waveguide is not limited to a cylindrical shape. For example, the waveguide may be a rectangular tube. It is preferable that the shape of the protruding portion of the closing member is a shape that matches the shape of the waveguide and follows the shape of the cavity of the waveguide.

It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be construed as limiting. The above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

This application claims priority to basic patent application No. 2020-058877, filed on March 27, 2020, with the Japan Patent Office, the entire contents of which are incorporated herein by reference.

REFERENCE SIGNS LIST 10 Closing member 10a Base portion 10b Protruding portion 20 Waveguide 20e End surface 20h Cavity 21 Dielectric tube 22 Metal coating 110 Closing member 210 Closing member 310 Closing member

Claims (9)

A conductive waveguide closing member for closing an end of a waveguide, the waveguide having a dielectric layer having a hollow interior and a metal layer covering the outside of the dielectric layer,
A flat base portion,
a protrusion provided so as to protrude from a main surface of the base portion,
the protrusion is inserted into the cavity from the end and attached to the waveguide ;
When the distance from the main surface to the end face of the protrusion is L1, the wavelength of the electromagnetic wave propagating through the dielectric layer is λ _g , and n1 is a non-negative integer,

Fulfilling
A closure for a waveguide. The protrusion is formed to conform to the shape of the cavity.
2. A waveguide closure as claimed in claim 1. The protrusion is cylindrical.
A closure for a waveguide according to claim 1 or 2. The protrusion is frustoconical.
2. A waveguide closure as claimed in claim 1. a visor portion protruding from the main surface and positioned outside the protruding portion,
The overhanging portion is provided on the outside of the metal layer when attached to the waveguide.
A closure for a waveguide according to any one of claims 1 to 4 . The eaves portion has a narrow tip.
A waveguide closure as claimed in claim 5 . When the distance from the main surface to the end surface of the overhanging portion is L2, the frequency of the electromagnetic wave propagating through the cavity is λ _o , and n2 is a non-negative integer,

Fulfilling
A closure for a waveguide according to claim 5 or 6 . 8. A waveguide closing member according to claim 1 , which is made of a resin having a film of a conductive material formed on its surface. A waveguide including a dielectric layer having an interior cavity and a metal layer covering the outside of the dielectric layer;
a conductive waveguide closing member that closes an end of the waveguide,
The waveguide closure member comprises:
A flat base portion;
a protrusion provided so as to protrude from a main surface of the base portion,
the protrusion is inserted into the cavity from the end and attached to the waveguide ;
When the distance from the main surface to the end face of the protrusion is L1, the wavelength of the electromagnetic wave propagating through the dielectric layer is λ _g , and n1 is a non-negative integer,

Fulfilling
Waveguide with closure.

Images