JP6964824B2 - Converter and antenna device - Google Patents

Description

The present invention relates to a transducer having a post-wall waveguide and an antenna device including the same.

The post-wall waveguide is a waveguide in which conductors provided on both sides of a dielectric are electrically connected by a through hole called a post, which is a through conductor. Post-wall waveguides are also referred to as dielectric substrate integrated waveguides (SIWs). As a conventional converter having a post-wall waveguide, for example, there is one described in Non-Patent Document 1. The converter described in Non-Patent Document 1 is composed of two substrates vertically connected to each other, and a post-wall waveguide is provided on one of these substrates.

B. Y. E. Khatib, et. al. , “Substrate-Integrated Waveguide Virtual Interfaces for 3-D Integrated Circuits”, IEEE Transfers. on Comp. , Packaging and Manufacturing Tech. , Vol. 2, pp. 1526-153, Sept. 2012.

In the conventional transducer described in Non-Patent Document 1, the end portion of the other substrate is inserted into the through hole provided in one substrate, and the end portion of the substrate inserted into the through hole is soldered. By fixing, the two boards are connected vertically to each other. In this structure, it is necessary to allow the through hole or the substrate to have a dimensional allowance so that the end portion of the substrate is surely inserted into the through hole. Therefore, a gap is often generated between the end of the substrate inserted into the through hole and the inner peripheral surface of the through hole, and in this case, the electrical characteristics of the converter are significantly deteriorated.

On the other hand, there is also a converter in which two substrates are vertically connected to each other without providing a through hole in the substrate by utilizing electromagnetic coupling using a slot provided in the substrate. However, when the post-wall waveguide is provided on the substrate, it becomes impossible to provide the conductor at the end of the substrate in manufacturing. Therefore, there is a problem that the substrate provided with the post-wall waveguide cannot be electrically connected to the other substrate, and radio waves leak from the end of the substrate provided with the post-wall waveguide.

The present invention solves the above problems, and an object of the present invention is to obtain a converter capable of preventing leakage of radio waves and an antenna device provided with the converter.

The converter according to the present invention has a first dielectric substrate whose both sides are covered with conductors, conductors on both sides of the first dielectric substrate, and conductors on both sides that penetrate the first dielectric substrate. A first post-wall dielectric path composed of a plurality of through holes electrically connecting the two, and a conductor pattern whose front surface is covered with a ground conductor and has signal input / output terminals are provided on the back surface. It comprises a second dielectric substrate, one or more slots provided in a ground conductor, and a metal member that secures the first dielectric substrate on the surface of the second dielectric substrate. .. On the surface of the second dielectric substrate, the first dielectric with one end of the first post-wall waveguide facing the surface and the end of the first dielectric substrate facing the slot. A body substrate is provided. The metal member is a groove having a depth of one-fourth of the signal propagation wavelength at a position separated from the position where the first post-wall waveguide is electrically short-circuited by one-fourth of the signal propagation wavelength. It has.

According to the present invention, on the surface of the second dielectric substrate, one end of the first post-wall waveguide faces the surface, and the end of the first dielectric substrate faces the slot. The first dielectric substrate is provided at the metal member, and the metal member has a signal propagation wavelength at a position one-fourth of the signal propagation wavelength from the position where the first post-wall waveguide is electrically short-circuited. It has a groove with a quarter depth. By having this configuration, the radio wave of the signal propagating through the first post-wall waveguide is coupled to the slot by the second dielectric substrate and further coupled to the conductor pattern, so that the leakage of the radio wave can be prevented. Can be done.

It is a perspective view which shows the converter which concerns on Embodiment 1. FIG. FIG. 5 is a cross-sectional arrow diagram showing a cross section of the converter according to the first embodiment cut along the line AA of FIG. It is a top view which shows the converter which concerns on Embodiment 1. FIG. FIG. 4A is a plan view showing the first dielectric substrate. FIG. 4B is a cross-sectional arrow showing a cross section of the first dielectric substrate cut along the line BB of FIG. 4A. FIG. 5A is a plan view showing the back surface of the second dielectric substrate. FIG. 5B is a cross-sectional arrow showing a cross section of the second dielectric substrate cut along the line CC of FIG. 5A. It is a partially enlarged view which shows the post-wall waveguide. It is a graph which shows the reflection characteristic obtained by the electromagnetic field analysis. FIG. 8A is a plan view showing a modified example of the post-wall waveguide provided on the first dielectric substrate. FIG. 8B is a cross-sectional arrow showing a cross section of the dielectric substrate of FIG. 8A cut along the DD line of FIG. 8A. It is a partially enlarged view which shows the modification of the post-wall waveguide. It is a perspective view which shows the antenna device which concerns on Embodiment 1. FIG.

Embodiment 1.
FIG. 1 is a perspective view showing a converter according to the first embodiment. FIG. 2 is a cross-sectional arrow diagram showing a cross section of the converter according to the first embodiment cut along the line AA of FIG. FIG. 3 is a top view showing the converter according to the first embodiment. FIG. 4A is a plan view showing the first dielectric substrate 11. FIG. 4B is a cross-sectional arrow showing a cross section of the first dielectric substrate 11 cut along the line BB of FIG. 4A. FIG. 5A is a plan view showing the back surface of the second dielectric substrate 12. FIG. 5B is a cross-sectional arrow showing a cross section of the second dielectric substrate 12 cut along the line CC of FIG. 5A. FIG. 6 is a partially enlarged view showing the post-wall waveguide 16.

In FIGS. 1 to 6, the x-axis, y-axis, and z-axis are three axes perpendicular to each other. The direction parallel to the x-axis is defined as the x-axis direction, the direction parallel to the y-axis is defined as the y-axis direction, and the direction parallel to the z-axis is defined as the z-axis direction. Further, among the x-axis directions, the direction indicated by the arrow is defined as the plus x direction, and the direction opposite to the plus x direction is defined as the minus x direction. Similarly, of the y-axis directions, the direction indicated by the arrow is defined as the plus y direction, and the direction opposite to the plus y direction is defined as the minus y direction. Of the z-axis directions, the direction indicated by the arrow is the plus z direction, and the direction opposite to the plus z direction is the minus z direction.

As shown in FIGS. 1, 2 and 3, the converter according to the first embodiment includes a first dielectric substrate 11, a second dielectric substrate 12, and a pair of metal plates 13a and 13b. The first dielectric substrate 11 and the second dielectric substrate 12 are flat plate members made of a resin material. Although both substrates 11 and 12 have been shown as a single-layer substrate, these substrates 11 and 12 may be multi-layer substrates. By using a multilayer board, the degree of freedom in designing the wiring provided on the dielectric board is improved.

Further, in the first dielectric substrate 11, both sides of the dielectric 11a, which is a flat plate member, are covered with conductors. One surface of the dielectric 11a is covered with the ground conductor 11b, and the other surface of the dielectric 11a is covered with the ground conductor 11b. A plurality of through holes 15a for electrically connecting the grounding conductor 11b and the grounding conductor 11b are formed on the first dielectric substrate 11.

The post-wall waveguide 15 is a first post-wall waveguide composed of ground conductors 11b provided on both sides of the first dielectric substrate 11 and a plurality of through holes 15a. The converter according to the first embodiment is a converter that vertically converts the propagation directions of signals propagating in the post-wall waveguide 15 to each other. As shown in FIG. 4A, the post-wall waveguide 15 is, for example, a block composed of three rows of through-hole rows (block on the minus x direction side) and a block composed of three rows of through-hole rows (blocks in the minus x direction). It is configured to include a block on the plus x direction side). However, the three through-hole rows are an example, and the through-hole rows in one block may be one row. The area of the broken line with the symbol P between the blocks is the portion where the signal propagates. The distance between the two blocks is more than half of the propagation wavelength in consideration of the dielectric constant. Further, the diameter of the through holes 15a is arbitrary, and the distance between the through holes 15a is one-fourth or less of the propagation wavelength of the signal.

In the second dielectric substrate 12, as shown in FIGS. 5A and 5B, the surface (plane in the plus z direction) of the dielectric 12a which is a flat plate member is covered with the ground conductor 12b, and the back surface (minus) of the dielectric 12a is covered. Conductor patterns 12c and 12d having signal input / output terminals are provided on the surface in the z direction).

As shown in FIGS. 1 and 2, a first dielectric substrate 11 is provided on the surface of the second dielectric substrate 12. At this time, one end of the post-wall waveguide 15 is in a state of facing the surface of the dielectric 12a. As shown in FIG. 4A, one end of the post-wall waveguide 15 is the end A of the through-hole row formed on the first dielectric substrate 11 in the minus z direction.

As shown by the broken lines in FIGS. 5A and 6, the ground conductor 12b is provided with a slot 17. The end portion A shown in FIG. 4A of the first dielectric substrate 11 is in a state of facing the slot 17. Although the case where the number of slots 17 is one is shown, a plurality of slots 17 may be provided in the region of the ground conductor 12b facing the end A of the first dielectric substrate 11.
The end A of the first dielectric substrate 11 is a portion where no conductor is provided. In the manufacture of a converter, for example, when a dielectric substrate is cut by a cutting tool or laser processing, the corners of the substrate edge (the portion corresponding to the end portion A) are removed and rounded. Since the roundness of such an end is not controlledly formed, if a conductor pattern is provided on the rounded end, it may affect the electrical characteristics of the converter and make it unstable. There is sex. Therefore, no conductor is provided at the end A of the first dielectric substrate 11.

The grounding conductor 12b in the second dielectric substrate 12 is formed, for example, by crimping a copper foil, which is a conductive metal foil, to the surface of the dielectric 12a. As the grounding conductor 12b, a metal plate thicker than the metal foil can be used. In this case, a metal plate formed of a metal material is attached to the surface of the dielectric 12a as a ground conductor 12b.

The conductor patterns 12c and 12d on the second dielectric substrate 12 are formed by, for example, patterning a copper foil which is a conductive metal foil provided on the back surface of the dielectric 12a. Further, as the conductor patterns 12c and 12d, a metal plate thicker than the metal foil may be used.

Further, the second dielectric substrate 12 is provided with a post-wall waveguide 16. The post-wall waveguide 16 penetrates the grounding conductor 12b on the front surface of the dielectric 12a, the strip-shaped conductor pattern 12c on the back surface of the dielectric 12a, and the grounding conductor 12b and the conductor pattern 12c through the second dielectric substrate 12. It is a second post-wall waveguide composed of a plurality of through holes 16a and 16b that are electrically connected. In the post-wall waveguide 15 and the post-wall waveguide 16, the aa line along the tube axis of the through hole 15a shown in FIG. 1 and the bb line shown in FIG. 5A are orthogonal to each other. The aa line and the CC line shown in FIG. 5A are arranged so as to be parallel to each other.

In the second dielectric substrate 12, the ground conductor 12b provided on the front surface and the conductor pattern 12d provided on the back surface form a microstrip line. The conductor pattern provided on the second dielectric substrate 12 may be only the post-wall waveguide 16 described above, or may be a strip line or a coplanar line. Further, the coplanar line may be adjacent to the ground conductor.

The conductor pattern 12d has a characteristic impedance corresponding to the width of the conductor pattern. The shape of the conductor pattern 12d shown in FIG. 5A is an example, and the shape is changed according to the reflection matching condition.

As shown in FIGS. 1 to 3, the metal plate 13a and the metal plate 13b are attached to the surface of the second dielectric substrate 12 by soldering or the like, and the first dielectric substrate 11 is attached to the first dielectric substrate 11. It is a metal member fixed on the surface of the dielectric substrate 12 of 2. The first dielectric substrate 11 is sandwiched between the metal plate 13a and the metal plate 13b on the surface of the second dielectric substrate 12. The metal member for fixing the first dielectric substrate 11 on the surface of the second dielectric substrate 12 is not limited to the two metal plates 13a and 13b, and the first dielectric substrate 11 is used. It may be a single metal plate having a gap for fitting and fixing.

Further, since the metal plate 13a and the metal plate 13b are in contact with the ground conductor 12b and are grounded, the portion of the first dielectric substrate 11 in contact with the metal plate 13a and the metal plate 13b is also grounded. .. The grounded portion of the first dielectric substrate 11 includes a portion of the post-wall waveguide 15 as shown in FIGS. 1 and 2. Therefore, the part of the post-wall waveguide 15 in contact with the metal plate 13a or the metal plate 13b is electrically short-circuited.

As shown in FIGS. 1 and 2, the metal plate 13a is provided with a groove 14a, and the metal plate 13b is provided with a groove 14b. As shown in FIG. 3, the groove 14a and the groove 14b are signals at a position P2 where the post-wall waveguide 15 is electrically short-circuited at a position P1 which is separated by a distance L1 which is a quarter of the propagation wavelength of the signal. It is a U-shaped groove having a depth (length in the plus z direction) of 1/4 of the propagation wavelength of. The bottom surface of the groove 14a and the groove 14b is open in a U shape, and both ends thereof are open in a square shape. The grooves 14a and 14b provided in the metal plates 13a and 13b are surrounded by conductors, and can prevent radio wave leakage in all directions. When the grooves 14a and 14b are formed by drilling the metal plates 13a and 13b, R is generated at the corners of the grooves 14a and 14b to form a U shape. However, the grooves 14a and 14b may be processed so that corners remain. The effect of preventing radio wave leakage can be obtained even if the bottom surfaces and both ends of the grooves 14a and 14b are open.

As shown in FIG. 4A, the post-wall waveguide 15 includes a plurality of through-hole rows composed of a plurality of through-holes 15a. In FIG. 4A, a plurality of through-hole rows of the post-wall waveguide 15 are aligned in the z-axis direction. Further, the post-wall waveguide 15 has a rectangular end face portion having a long side parallel to the x-axis direction and a short side parallel to the y-axis direction.

In the plurality of through-hole rows of the post-wall waveguide 15, some through-hole rows may be disturbed. Due to the disorder of the through-hole rows, some of the plurality of through-holes constituting the through-hole row may be out of alignment with the remaining through-hole rows, or the distance between adjacent through-hole rows may be different. May be out of alignment. As described above, since some through-hole rows are disturbed in the post-wall waveguide 15, there is an effect that parasitic inductance is added and contributes to wideband matching.

As shown in FIG. 6, the post-wall waveguide 16 includes a plurality of through-hole rows composed of a plurality of through-holes 16a and 16b. The plurality of through-hole rows of the post-wall waveguide 16 are aligned in the y-axis direction. The number of through holes constituting the post-wall waveguide 16 is changed according to the design specifications.

The slot 17 is formed in the xy region of the second dielectric substrate 12 that faces the end portion of the first dielectric substrate 11 and is covered by the end surface portion of the post-wall waveguide 15. 5A and 6 show a case where the shape of the slot 17 is rectangular (-shaped), but it may be H-shaped. One slot 17 may be provided in the xy region covered by the end face portion of the post wall waveguide 15, or a plurality of slots 17 may be provided.

Next, the operation of the converter according to the first embodiment will be described.
When a basic mode signal is input to the post-wall waveguide 15, this signal propagates through the post-wall waveguide 15 and then couples into a slot 17 provided in the ground conductor 12b of the second dielectric substrate 12. do. Subsequently, the signal coupled to the slot 17 is coupled to the conductor pattern 12c and the conductor pattern 12d of the second dielectric substrate 12, propagates to the input / output terminal side, and is output from the input / output terminal. The input / output terminals are provided at the ends of the strip-shaped conductor pattern 12d on the side opposite to the side connected to the conductor pattern 12c.

FIG. 7 is a graph showing the reflection characteristics obtained by the electromagnetic field analysis, and shows the reflection characteristics obtained by performing the electromagnetic field analysis on the converter according to the first embodiment and the converter to be compared. There is. The converter to be compared has the same basic configuration as the converter according to the first embodiment, except that the metal plates 13a and 13b do not have grooves 14a and 14b. In FIG. 7, the data assigned by the reference numeral D1 is the reflection characteristic data obtained by performing electromagnetic field analysis on the converter to be compared. The data with reference numeral D2 is reflection characteristic data obtained by performing electromagnetic field analysis on the converter according to the first embodiment.

As shown in FIG. 7, in the converter according to the first embodiment, the reflection due to the leakage of radio waves is reduced by providing the grooves 14a and 14b in the metal plates 13a and 13b, and good reflection at a desired frequency is achieved. Shows the characteristics. This means that there is no leakage of radio waves from the end A of the first dielectric substrate 11 shown in FIGS. 4A and 4B. It should be noted that the same reflection characteristics as those in FIG. 7 can be obtained in the converters having the configurations described later with reference to FIGS. 8 and 9.

Next, a modification of the converter according to the first embodiment will be described.
FIG. 8A is a plan view showing a modification of the post-wall waveguide provided on the first dielectric substrate 11A, and shows the post-wall waveguide 15A which is a modification of the post-wall waveguide 15. FIG. 8B is a cross-sectional arrow showing a cross section of the first dielectric substrate 11A of FIG. 8A cut along the DD line of FIG. 8A. The post-wall waveguide 15A includes a plurality of through-hole rows composed of a plurality of through-holes 15a. These through-hole rows are aligned in the z-axis direction, but some through-holes 15a are removed on one end side of the post-wall waveguide 15A.

The portion of the post-wall waveguide 15A from which the through-holes 15a have been removed is adjacent to the remaining through-holes 15a on the other end of the post-wall waveguide 15A, as shown in FIG. 8A. A portion 21 surrounded by through holes 15a in a row of through holes. As shown in FIG. 8B, the dielectric 11a of the first dielectric substrate 11 exists in this portion 21. Therefore, the portion 21 can be regarded as a groove portion in which a plurality of through holes 15a are present around the portion 21 and the dielectric material 11a is filled inside the first dielectric substrate 11A. This portion 21 realizes a so-called choke structure and prevents unnecessary radio wave propagation along the x-axis direction.

Further, the second post-wall waveguide may be configured as follows.
FIG. 9 is a partially enlarged view showing a modified example of the second post-wall waveguide, showing the post-wall waveguide 16A which is a modified example of the post-wall waveguide 16. The post-wall waveguide 16A includes a plurality of through-hole rows composed of a plurality of through-holes 16a and 16b. These through-hole rows are aligned in the y-axis direction, but the through-hole rows on the slot 17 side are disturbed. For example, with respect to the arrangement of the through holes 16a along the y-axis direction, the through holes 16b in the post wall waveguide 16A on the left side are displaced in the minus x-axis direction, and a part of the through hole row is disturbed, and the post on the right side. The through holes 16b in the wall waveguide 16A are displaced in the plus x-axis direction, and a part of the through hole rows is disturbed. Since the disturbance of the through-hole row adds a parasitic inductance, the resonance frequency existing in the low frequency band can be moved to a desired frequency band. This makes it possible to widen the frequency characteristics.

Next, the antenna device including the converter described so far will be described.
FIG. 10 is a perspective view showing the antenna device according to the first embodiment. The antenna device shown in FIG. 10 has a structure in which a planar antenna for transmitting and receiving microwaves or millimeter waves is connected to an end portion of the first dielectric substrate 11. As shown in FIG. 10, a substrate which is a flat antenna is provided with a conductor pattern of a microstrip line 18 and a plurality of antenna elements 19. By connecting the substrate, which is a planar antenna, to the end of the first dielectric substrate 11, the planar antenna can be erected in the front direction, and radio waves are radiated in the z-axis direction.

As described above, in the converter according to the first embodiment, on the surface of the second dielectric substrate 12, one end of the post-wall waveguide 15 faces the surface, and the first dielectric substrate 11 The first dielectric substrate 11 is provided with the end A facing the slot 17. Further, the metal plates 13a and 13b have a depth of one-fourth of the signal propagation wavelength at a position P2 which is one-fourth of the signal propagation wavelength from the position P1 where the post-wall waveguide 15 is electrically short-circuited. It is provided with grooves 14a and 14b having a short circuit. By having this configuration, the radio wave of the signal propagating through the post-wall waveguide 15 is coupled to the slot 17 at the second dielectric substrate 12 and further coupled to the conductor patterns 12c and 12d, so that the radio wave leaks. Can be prevented.

The present invention is not limited to the above-described embodiment, and within the scope of the present invention, it is possible to modify any component of the embodiment or omit any component of the embodiment.

Since the converter according to the present invention can prevent the leakage of radio waves, it can be used for an antenna device that transmits a high frequency signal in the microwave band or the millimeter wave band.

11, 11A 1st dielectric substrate, 11a, 12a dielectric, 11b ground conductor, 12 second dielectric substrate, 12b ground conductor, 12c, 12d conductor pattern, 13a, 13b metal plate, 14a, 14b groove, 15 , 15A, 16, 16A Post-wall waveguides, 15a, 16a, 16b through-holes, 17 slots, 18 microstrip lines, 19 antenna elements, 21 parts.

Claims (7)

A first dielectric substrate whose both sides are covered with conductors,
A first post wall conductor composed of conductors on both sides of the first dielectric substrate and a plurality of through holes penetrating the first dielectric substrate and electrically connecting the conductors on both sides. Waveguide and
A second dielectric substrate whose front surface is covered with a ground conductor and whose back surface is provided with a conductor pattern having signal input / output terminals.
With one or more slots provided on the ground conductor
A metal member fixing the first dielectric substrate on the surface of the second dielectric substrate, and
With
On the surface of the second dielectric substrate, one end of the first post-wall waveguide faces the surface, and the end of the first dielectric substrate faces the slot. , The first dielectric substrate is provided,
The metal member has a depth of one-fourth of the propagation wavelength of the signal at a position separated from the position where the first post-wall waveguide is electrically short-circuited by one-fourth of the propagation wavelength of the signal. A converter characterized by having a groove having a. A second post wall composed of the ground conductor, the conductor pattern, and a plurality of through holes penetrating the second dielectric substrate and electrically connecting the ground conductor and the conductor pattern. The converter according to claim 1, further comprising a waveguide. The converter according to claim 1, wherein the conductor pattern is either a microstrip line, a strip line, or a coplanar line. Claim 1 is characterized in that the plurality of through-holes constituting the first post-wall waveguide is a plurality of aligned through-hole rows or a plurality of through-hole rows in which some of the through-hole rows are disturbed. Described converter. The converter according to claim 1, wherein some through holes are removed on one end side of the first post-wall waveguide. 2. The plurality of through-holes constituting the second post-wall waveguide is a plurality of aligned through-hole rows or a plurality of through-hole rows in which some of the through-hole rows are disturbed. Described converter. An antenna device including the converter according to any one of claims 1 to 6.

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