JP2011135479A - Waveguide sealing member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To seal an opening of a waveguide in a state where excellent propagation characteristic is maintained even for an electromagnetic wave having a short wavelength band exceeding 100 GHz. <P>SOLUTION: A waveguide sealing material has a tabular metal plate 11 which has a passage hole A for passing an electromagnetic wave propagating through the inside of a waveguide 30 and is bonded so as to cover the opening B of the waveguide 30 and a dielectric 12 sealed to the passage hole A formed on the metal plate 11. In the material, the shape of the passage hole A and/or the dielectric constant of the dielectric 12 can be changed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a technique for sealing a waveguide.

  Conventionally, there is an IC chip in which a large number of elements are combined to perform a specific complicated function, and the IC chip is usually stored in a housing. In addition, a hole for a transmission line that allows a predetermined signal to pass through the IC chip is formed on one side surface of such a case, and the IC chip stored inside is protected from the outside atmosphere. Therefore, it may be necessary to seal the hole and make the inside of the housing airtight while securing a transmission path. For example, when the hole functions as an input / output unit for analog signals and the terminal of the input / output unit is a coaxial terminal, use a coaxial terminal for sealing in which the dielectric portion of the coaxial terminal is replaced with glass Is used.

  However, in a frequency band exceeding 30 GHz such as a millimeter wave or a terahertz wave, a waveguide may be used as a terminal of the input / output unit, and the above-described sealing coaxial terminal is often not usable.

  Therefore, in Patent Document 1, as shown in FIG. 6, a dielectric 12 having a width larger than the width of the opening B in the waveguide 30 (corresponding to the circuit board of Patent Document 1) is used, and the waveguide A technique for bonding so as to close 30 openings B is disclosed. Since the space between the dielectric 12 and the waveguide 30 is filled with the adhesive 40, the IC chip (not shown) in the housing can be protected from the outside atmosphere.

  However, the wavelength in the frequency band exceeding 100 GHz is very short, and the size (specifically, the difference width between the dielectric 12 and the opening B) and the thickness of the dielectric 12 that closes the opening B are smaller than the wavelength. Therefore, there is a problem that quality control such as propagation characteristics becomes very difficult. Hereinafter, the WR-8 waveguide will be described as an example.

  The WR-8 waveguide handles signals from 90 GHz to 140 GHz, and the size of the opening B is 1.016 mm long × 2.032 mm wide as shown in FIG. Here, in order to close the opening B having such a size, for example, 1 mm in each of the longitudinal direction and the lateral direction from each side of the opening B in the waveguide 30 based on the technique disclosed in the cited document 1. It is conceivable to use a dielectric 12 having a size that is expanded to some extent. Then, the size of the dielectric 12 is 3.016 mm in length × 4.032 mm in width, and the opening width of the waveguide 30 is apparently twice or more larger in both length and width. Further, in consideration of the wavelength shortening effect (the effect of shortening the effective wavelength of the radio wave propagating in the substance having a dielectric constant greater than 1) due to the dielectric 12, the effective opening surface of the waveguide 30 is further increased. Become. Thereby, for example, when the relative dielectric constant of the dielectric 12 is 4, the opening surface of 3.016 mm long × 4.032 mm wide based on the size of the dielectric 12 is further doubled by the effect of the dielectric constant. This corresponds to an opening of 6.032 mm in length × 8.064 mm in width. That is, the size of the effective opening surface of the waveguide 30 is significantly different due to the influence of the dielectric 12 bonded to the opening B of the waveguide 30. As a result, as described above, the propagation characteristics, etc. Quality control becomes difficult.

  One of the harmful effects of such a change in the size of the effective aperture in the waveguide is the generation of higher-order modes. The higher order mode is a mode in which the direction of the electric field of the electromagnetic wave is different from the propagation mode assumed by the waveguide, which leads to an increase in passage loss and deterioration of reflection characteristics. In addition to this, there is also an adverse effect that the characteristic impedance largely deviates before and after the opening in the waveguide. When a mismatch of characteristic impedance occurs, a reflected wave based on the impedance difference is generated in the waveguide, which greatly affects the propagation characteristics.

  The above-described adverse effect due to the change in the size of the effective aperture due to the installation of the dielectric is less affected when the thickness of the dielectric is sufficiently smaller than the wavelength of the radio wave. However, in the case of a waveguide that handles signals in a frequency band such as 90 GHz to 140 GHz such as the WR-8 waveguide, the wavelength of the propagating signal is short (the wavelength of the 90 GHz signal is about 3.3 mm, 140 GHz). The signal is about 2.1 mm), and the thickness of the dielectric used for the sealing application cannot be ignored. As a result, the adverse effect due to the change in the size of the effective aperture due to the installation of the dielectric increases, and good propagation characteristics cannot be obtained.

  Therefore, in order to obtain good propagation characteristics when the waveguide is sealed with a dielectric in a frequency band exceeding 100 GHz, first, in order to suppress the generation of higher-order modes, a dielectric is used. In order to make the opening of the sealing portion smaller than the opening of the waveguide and secondly to suppress mismatching of the characteristic impedance, it is necessary to be able to arbitrarily design the characteristic impedance of the sealing portion.

JP 2002-261517 A

  However, according to the technique disclosed in the cited document 1, a dielectric is placed and sealed in the middle of the waveguide, and the dielectric is opened by the width as a margin necessary for placement. Therefore, there is a problem that the first condition described above cannot be satisfied structurally.

  In addition, since the shape of the dielectric changes depending on the margin for placing the dielectric and the flow of the adhesive, there is a problem that the characteristic impedance that is the second condition cannot be controlled with high accuracy.

  The present invention has been made in view of the above problems, and seals the opening of the waveguide while maintaining good propagation characteristics against electromagnetic waves in a short wavelength band exceeding 100 GHz. Let it be an issue.

  According to the first aspect of the present invention, in the waveguide sealing material for sealing the opening of the waveguide, a passage hole through which the electromagnetic wave propagating through the waveguide is passed is formed. A plate-like conductor bonded to the waveguide so as to cover the portion, and a dielectric sealed in the passage hole formed in the conductor, and / or the shape of the passage hole and / or The dielectric constant of the dielectric can be changed.

  According to the present invention, since the shape of the through hole and / or the dielectric constant of the dielectric can be changed, the characteristic impedance at the through hole determined based on the shape of the through hole and / or the dielectric constant of the dielectric can be arbitrarily set. It becomes possible to design. In addition, since the dielectric is sealed in a through hole formed in the conductor, and the conductor is bonded to the waveguide, the change in the shape of the dielectric due to the flow of the adhesive is prevented. Is possible. As a result, mismatch (difference) between the characteristic impedance at the passage hole and the characteristic impedance inside the waveguide can be suppressed, and the waveguide opening is sealed while maintaining good propagation characteristics. can do.

  The present invention according to claim 2 is characterized in that the size of the passage hole is smaller than the size of the opening of the waveguide.

  According to the present invention, since the size of the through hole is smaller than the size of the opening of the waveguide, it is possible to suppress the generation of higher order modes.

  The present invention according to claim 3 is characterized in that the shape of the through hole and / or the dielectric constant of the dielectric is determined based on the shape of the through hole and / or the dielectric constant of the dielectric. The impedance is determined to be the same as the characteristic impedance inside the waveguide.

  According to the present invention, the shape of the through hole and / or the dielectric constant of the dielectric is determined based on the shape of the through hole and / or the dielectric constant of the dielectric. Since it is determined to be the same as the characteristic impedance, mismatch (difference) between the characteristic impedance at the passage hole and the characteristic impedance inside the waveguide can be suppressed more reliably, and the propagation is better. The waveguide opening can be sealed while maintaining the characteristics.

  The present invention described in claim 4 is characterized in that the shape of the passage hole is the same as the shape of the opening of the waveguide.

  The present invention according to claim 5 is characterized in that the shape of the passage hole is point-symmetric, and the middle point of the passage hole overlaps the middle point of the opening of the waveguide.

  According to the present invention, since the midpoint of the passage hole overlaps the midpoint of the opening of the waveguide, it is possible to seal the opening of the waveguide while maintaining a better propagation characteristic.

  The present invention according to claim 6 is characterized in that the shape of the through hole is at least one of a polygon, a circle, an ellipse, a concave, a convex, and a star.

  According to the present invention, it is possible to seal the opening of the waveguide while maintaining good propagation characteristics against electromagnetic waves in a short wavelength band exceeding 100 GHz.

It is the perspective view which looked at the waveguide sealing material which concerns on 1st Embodiment from the perspective direction. It is the perspective view which looked at the waveguide sealing material which concerns on 2nd Embodiment from the perspective direction. It is a figure which shows an example of the shape of the passage hole formed in the metal plate. It is a figure which shows the state which adhere | attaches a waveguide sealing material on a waveguide in the state which the midpoint of the passage hole has overlapped with the midpoint of the opening part. It is the figure which looked at the positional relationship of a passage hole and an opening part from the upper direction. It is a figure explaining the conventional sealing technique. It is a figure explaining the shape of the dielectric material used for the conventional sealing technique.

  Hereinafter, a waveguide sealing material according to an embodiment will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a perspective view of the waveguide sealing material according to the first embodiment viewed from a perspective direction. The waveguide sealing material 10 is composed of a flat metal plate 11 and a dielectric 12 whose both surfaces are flattened, and the peripheral region of the metal plate 11 is formed in an opening B ( More precisely, the opening B of the waveguide 30 is sealed by adhering to the opening end of the waveguide 30 forming the opening B using an adhesive (not shown). The IC chip (not shown) stored in the housing is protected from the outside atmosphere.

  Then, in the central region of the metal plate 11, an electromagnetic wave propagating through the inside of the waveguide 30 (electromagnetic wave propagating upward from the lower side in FIG. 1) is passed, so that the opening of the waveguide 30 is passed. A passage hole A having the same shape as B is formed, and a dielectric 12 such as glass is sealed in the formed passage hole A. At present, there are various types of waveguides depending on the frequency characteristics of signals to be handled. The mainstream waveguide is a rectangular waveguide or a circular waveguide, and the shape of the opening is a rectangle or a circle with an aspect ratio of about 1: 2, but the waveguide described in this embodiment is The following description will be made assuming that the shape of the passage hole A of the metal plate 11 is a rectangular waveguide.

  Here, in the present embodiment, each value of the horizontal length x, the vertical length y, and the thickness d constituting the shape of the passage hole A formed in the metal plate 11, and the dielectric 12 The value of the dielectric constant ε is a parameter that can be arbitrarily changed. That is, since the shape of the through hole A formed in the metal plate 11 and the dielectric constant of the dielectric 12 are variable, the characteristic impedance at the through hole A determined by the shape of the through hole A and the dielectric constant of the dielectric 12 Can be arbitrarily set by the designer. As a result, mismatching (difference) between the characteristic impedance at the passage hole A and the characteristic impedance inside the waveguide 30 can be suppressed, and the waveguide opening can be maintained while maintaining good propagation characteristics. Can be sealed.

  In addition, the dielectric 12 is sealed in a passage hole A formed in the metal plate 11 (simply fitted into the passage hole A), and adhesion to the opening B of the waveguide 30 is dielectric. Since it is made of the metal plate 11 instead of the body 12, it is possible to prevent a change in the shape of the dielectric caused by the flow of the adhesive used for the bonding. As a result, mismatch between the characteristic impedance at the passage hole A and the characteristic impedance inside the waveguide 30 can be suppressed, and the waveguide opening is sealed while maintaining good propagation characteristics. can do.

  Furthermore, since the value of the horizontal length x and the value of the vertical length y among the elements constituting the shape of the passage hole A of the metal plate 11 can be arbitrarily set, as shown in FIG. In addition, the size of the passage hole A can be made smaller than the size of the opening B of the waveguide 30. As a result, it is possible to simultaneously obtain the effect of suppressing the above-described characteristic impedance mismatch and the effect of suppressing the generation of higher-order modes.

  Further, each of the horizontal length x, the vertical length y, and the thickness d of the passage hole A is set so that the characteristic impedance at the passage hole A is the same as the characteristic impedance inside the waveguide 30. It is also possible to design the value of the dielectric constant ε of the dielectric 12. As a result, the above-described mismatch in characteristic impedance can be more reliably suppressed, and the opening of the waveguide can be sealed while maintaining better propagation characteristics.

  In addition, regarding the value of the thickness d, in order to satisfy desired sealing characteristics and durability characteristics, the minimum value is limited, but the maximum value can be arbitrarily set. For example, the value of the thickness d can be set near an integral multiple of half the wavelength of the electromagnetic wave passing through the dielectric 12 to further reduce the influence of the difference in characteristic impedance.

  In this embodiment, the waveguide is a rectangular waveguide, and the shape of the opening is a rectangle. However, in actual fabrication, the corner of the rectangle is not exactly a right angle, and drilling is used. When created, it is generally a circular arc. Even in such a case, the waveguide sealing material described in this embodiment can be applied if it can be sufficiently approximated as a rectangular parallelepiped in view of propagation characteristics.

[Second Embodiment]
In the first embodiment, the case where the waveguide 30 is a rectangular waveguide has been described. In the second embodiment, a case where a circular waveguide having a circular opening is used. explain. FIG. 2 is a perspective view of the waveguide sealing material according to the second embodiment viewed from the perspective direction. As with the waveguide sealing material 10 described in the first embodiment, the waveguide sealing material 10 is composed of a metal plate 11 and a dielectric 12. The opening B of the waveguide 30 is sealed by adhering to the opening B of the waveguide 30 using an adhesive or the like.

  A circular passage hole A is formed in the central region of the metal plate 11 in order to allow the electromagnetic wave propagating through the waveguide 30 to pass therethrough, and the dielectric 12 is formed in the formed passage hole A. Sealed.

  Here, in the present embodiment, parameters that can arbitrarily change each value of the length r and thickness d of the diameter constituting the shape of the passage hole A and the value of the dielectric constant ε of the dielectric 12. It is said. That is, since the shape of the through hole A formed in the metal plate 11 and the dielectric constant of the dielectric 12 can be varied, the shape of the through hole A and the dielectric of the dielectric 12 can be changed as in the first embodiment. The characteristic impedance at the passage hole A determined by the ratio can be arbitrarily set by the designer. As a result, mismatch between the characteristic impedance at the passage hole A and the characteristic impedance inside the waveguide 30 can be suppressed, and the waveguide opening is sealed while maintaining good propagation characteristics. can do.

  In addition, the dielectric 12 is sealed in the passage hole A formed in the metal plate 11, and further, the adhesion to the waveguide 30 is made not by the dielectric 12 but by the metal plate 11. Similar to the embodiment, it is possible to prevent a change in the shape of the dielectric due to the flow of the adhesive used for the bonding. As a result, mismatch between the characteristic impedance at the passage hole A and the characteristic impedance inside the waveguide 30 can be suppressed, and the waveguide opening is sealed while maintaining good propagation characteristics. can do.

  Furthermore, since the value of the length r of the diameter among the elements constituting the shape of the passage hole A of the metal plate 11 can be arbitrarily set, the size of the passage hole A is the same as in the first embodiment. It is possible to make the thickness smaller than the size of the opening B of the waveguide 30. As a result, it is possible to simultaneously obtain the effect of suppressing the above-described characteristic impedance mismatch and the effect of suppressing the generation of higher-order modes.

  Furthermore, each value of the length r and the thickness d of the diameter of the passage hole A and the dielectric of the dielectric 12 are set so that the characteristic impedance at the passage hole A is the same as the characteristic impedance inside the waveguide 30. It is also possible to design the value of the rate ε. As a result, similar to the first embodiment, the above-described characteristic impedance mismatch can be more reliably suppressed, and the waveguide opening is sealed while maintaining better propagation characteristics. be able to.

  In the first embodiment and the second embodiment, it has been described that the shape of the passage hole A formed in the metal plate 11 is the same as the shape of the opening B in the waveguide 30, but the opening B It is also possible to use those in which the passage holes A having different shapes are formed. For example, the waveguide sealing material described in the second embodiment can be used for a rectangular waveguide, and the waveguide waveguide described in the first embodiment can be used for a circular waveguide. It is also possible to use a wave tube sealing material.

  Further, since the shape of the passage hole A can be arbitrarily set, as shown in FIG. 3, the shape thereof is a polygon such as a triangle or a quadrangle (including a square or a rectangle), an ellipse, a concave The shape, convex shape, star shape, etc. can also be used.

  Furthermore, when the shape of the passage hole A is a point object such as a circle, a square, or a rectangle, the midpoint of the passage hole A in the metal plate 11 is an opening B in the waveguide 30 as shown in FIG. It is also possible to overlap with the midpoint. Thereby, the opening part of a waveguide can be sealed in the state which maintained the propagation characteristic still more favorably.

  Furthermore, in order to pass electromagnetic waves, the passage surface of the passage hole A only needs to overlap with a region of the opening surface of the opening B. Therefore, as shown in FIG. It is also possible to adhere the waveguide sealing material by shifting the position of A, or to form the passage hole A at a position where it deviates.

  Furthermore, since the shape of the passage hole A can be arbitrarily set, if the electromagnetic wave can be passed and the difference in characteristic impedance can be suppressed, the dielectric constant and thickness of the dielectric 12 are adjusted. By doing so, the size of the passage hole A can be made larger than the size of the opening B.

  Further, as the material of the dielectric 12, for example, the above-described glass or the like can be used. However, the electromagnetic wave propagating through the waveguide 30 can be passed and sealed with the metal plate 11, and sealed. Any type of dielectric may be used as long as the sealed state can be maintained for a long time.

  Further, regarding the adhesive or bonding procedure for bonding the waveguide sealing material 10 to the waveguide 30, for example, a marking for alignment is marked on the waveguide side and guided so as to match the marking. After adjusting the position of the wave tube sealing material 10 and / or the waveguide 30, brazing may be performed, but the waveguide sealing material 10 and the waveguide 30 are sealed. As long as it is possible to hold, any kind of adhesive or any step of bonding may be used. In particular, regarding the bonding procedure, the dielectric 12 may be sealed in the passage hole A of the metal plate 11 after the metal plate 11 is bonded to the waveguide 30.

  Finally, in the first embodiment and the second embodiment, the case where the waveguide 30 is a rectangular waveguide or a circular waveguide has been described. However, the shape of the opening B is not a square or a circle. It is also added that the waveguide sealing material described in both embodiments can be applied even to a waveguide having the shape described above.

  As described above, according to the waveguide sealing material according to the present invention, it is possible to seal the opening of the waveguide while maintaining good propagation characteristics against electromagnetic waves in a short wavelength band exceeding 100 GHz. it can. In addition, since it is not necessary to change the internal structure of the housing using the waveguide as the input / output unit, it can be said that application to an existing waveguide package is easy.

10 ... Waveguide sealing material 11 ... Metal plate (conductor)
12 ... Dielectric 30 ... Waveguide 40 ... Adhesive A ... Passing hole B ... Opening

Claims (6)

In the waveguide sealing material for sealing the opening of the waveguide,
A plate-shaped conductor formed in a through hole for passing the electromagnetic wave propagating through the waveguide and bonded to the waveguide so as to cover the opening;
A dielectric sealed in the through hole formed in the conductor;
A waveguide sealing material, wherein the shape of the passage hole and / or the dielectric constant of the dielectric can be changed. The size of the passage hole is
The waveguide sealing material according to claim 1, wherein the waveguide sealing material is smaller than the size of the opening of the waveguide. The shape of the through hole and / or the dielectric constant of the dielectric is
The characteristic impedance in the through hole determined based on the shape of the through hole and / or the dielectric constant of the dielectric is determined to be the same as the characteristic impedance in the waveguide. The waveguide sealing material according to claim 1 or 2. The shape of the passage hole is
The waveguide sealing material according to any one of claims 1 to 3, wherein the waveguide sealing material has the same shape as the opening of the waveguide. The shape of the through hole is point symmetric,
The waveguide sealing material according to any one of claims 1 to 4, wherein a midpoint of the passage hole overlaps a midpoint of the opening of the waveguide. The shape of the passage hole is
5. The waveguide sealing material according to claim 1, wherein the waveguide sealing material is at least one of a polygonal shape, a circular shape, an elliptical shape, a concave shape, a convex shape, and a star shape.

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