JP2007329908A - Dielectric substrate, waveguide tube, and transmission line transition device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dielectric substrate capable of forming a waveguide tube with excellent characteristics at low cost, the waveguide tube constituted using the dielectric substrate, and a transmission line transition device. <P>SOLUTION: A dielectric substrate 1 is a double coated substrate having thickness (d) with conductor layers 3, 5 constituted of conductive materials formed on both sides thereof, and a rectangular hole H, having the same inner diameter as the waveguide tube is formed in a central portion thereof. Furthermore, on the dielectric substrate 1, a plurality of vias 7 conducting the conductor layers 3, 5 are formed at fixed intervals W at positions away from an endface 9 to form an inner wall of the hole H thereon just by a fixed distance (via shift amount) δ. In such a case, when an intra-substrate wavelength within the dielectric substrate 1 in a frequency (f) of a transmission signal is defined as λg, it is set δ=λg/2, W≤λg/4. Since the end face 9 of the dielectric substrate 1 to be the inner walls of the waveguide tube is separated from the grounded vias 7 just by λg/2, on the dielectric substrate 1 thus constituted, the end face can be handled as virtually short-circuited. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a dielectric substrate forming a waveguide, a waveguide configured using the dielectric substrate, and a transmission line converter.

2. Description of the Related Art Conventionally, a technique for forming a waveguide by stacking dielectric substrates having holes formed therein is known.
Usually, in such a dielectric substrate, a conductor film is formed on the end face forming the inner wall of the waveguide (see, for example, Patent Document 1).

Also, instead of metallizing the end face, a plurality of vias (Via) are arranged at narrow intervals so as to surround the hole, and these vias are used as the inner wall of the waveguide (for example, patents). Reference 2).
Japanese Patent No. 3347626 JP 2001-196815 A

  By the way, in the former in which the conductor film is formed on the end face, the conductive ink is printed at the position to be the conductor film at the time of manufacturing the dielectric substrate (before firing), but as shown in FIG. On the narrow end face, there is a problem that it is difficult to make the thickness of the ink (and consequently the conductor film) constant due to the surface tension of the ink, which leads to deterioration of the characteristics of the waveguide.

  In addition, the formation of the conductor film on the end face requires a process different from the normal pattern formation on the dielectric substrate, so that there is a problem that the shape of the waveguide is restricted or the cost is increased. It was.

  On the other hand, in the latter case in which the inner wall of the waveguide is formed by a via, the via must be formed at a position away from the end face of the hole to some extent (for example, about 0.5 mm) due to the strength of the dielectric substrate. There was a problem that the position of the via could not coincide with the inner wall of the waveguide, which deteriorated the characteristics of the waveguide.

  In order to solve the above problems, the present invention provides a dielectric substrate capable of forming a waveguide having excellent characteristics at low cost, a waveguide configured using the dielectric substrate, and transmission line conversion The purpose is to provide a vessel.

  In order to achieve the above object, the invention according to claim 1 is a dielectric substrate having a hole used as a waveguide, and surrounds an end face of the hole forming an inner wall of the waveguide. And the 1st surrounding part which consists of a some via | veer arrange | positioned in the position where the said end surface becomes a virtual short circuit surface is provided, It is characterized by the above-mentioned.

  In the dielectric substrate of the present invention configured as described above, a waveguide is formed by arranging a via without providing a conductive film on the end face. Manufacturing is possible, and a waveguide can be formed at low cost.

  In addition, since the via is provided at a position where the end surface is a virtual short-circuited surface, that is, away from the end surface, the via can be guided in a low loss without reducing the strength of the dielectric substrate. A tube can be realized.

  Specifically, as described in claim 2, when the in-substrate wavelength of the electromagnetic wave propagating through the waveguide is λg, the via forming the first surrounding portion is n × λg / 2 from the end face (however, , N is a positive integer).

However, the position where the via is provided need not be exactly n × λg / 2, and may be shifted within a range of about ± 20%.
In order to efficiently prevent leakage of electromagnetic waves from between vias forming the first surrounding portion, the arrangement interval of vias forming the first surrounding portion is λg / 4 or less as described in claim 3. It is desirable that

Moreover, the dielectric substrate of the present invention may be provided with a second surrounding portion including a plurality of vias arranged at a position surrounding the first surrounding portion, as described in claim 4.
In this case, since the first surrounding portion and the second surrounding portion doubly prevent leakage of electromagnetic waves, the transmission efficiency of the waveguide formed by this dielectric substrate can be improved.

  In order to efficiently prevent leakage of electromagnetic waves from between the vias forming the second surrounding portion, the arrangement interval of the vias forming the second surrounding portion is λg / 4 or less as described in claim 5. It is desirable that

  Furthermore, in order to efficiently prevent leakage of electromagnetic waves leaking from the first surrounding portion at the second surrounding portion, the distance between the first surrounding portion and the second surrounding portion is λg as described in claim 6. / 2 or less is desirable.

  Next, a waveguide according to a seventh aspect is characterized by being formed by laminating a plurality of dielectric substrates according to any one of the first to sixth aspects. In other words, since the individually manufactured dielectric substrates are integrated later to form a waveguide, a waveguide having an arbitrary length can be easily obtained.

  In this case, the via (both forming the first surrounding portion and the via forming the second surrounding portion) is formed by aligning the plurality of stacked dielectric substrates in a straight line as described in claim 8. It is desirable that it is formed so as to penetrate through.

  Next, a transmission line converter according to a ninth aspect includes a waveguide forming portion having a structure in which one or a plurality of dielectric substrates according to the first to sixth aspects are laminated, and a waveguide. A planar line that is laminated on the waveguide forming part so as to block one end of the waveguide formed by the tube forming part, and transmits an electromagnetic wave, and the planar line and the electromagnetic wave that are located in the opening of the waveguide. And a conversion unit made of a dielectric substrate on which antenna patterns coupled to each other are formed.

  In addition, the waveguide formation part of these waveguides and a transmission line converter is comprised by integrating the dielectric substrate in any one of Claim 1 thru | or 6 manufactured later later. And each layer constituting the multilayer dielectric substrate is configured to have the same structure as the dielectric substrate according to any one of claims 1 to 6. There may be.

According to the waveguide and transmission line converter of the present invention configured as described above, uniform characteristics with small manufacturing variations can be realized.
In addition, the dielectric substrate according to any one of claims 1 to 6, and thus the waveguide forming portion in the transmission line converter according to claim 9 has a substrate thickness as shown in FIG. Even if this is changed, the characteristics (transmission loss) as a waveguide do not fluctuate greatly. For this reason, according to the transmission line converter of Claim 9, when designing a conversion part, the thickness of a dielectric substrate can be selected arbitrarily and the freedom degree of design can be increased.

  In the transmission line converter according to the present invention, the conversion unit is provided with a third surrounding portion including a plurality of vias at a position surrounding the portion facing the opening of the waveguide. It is desirable that

Thereby, the leakage of the electromagnetic wave from a conversion part can be prevented, and the transmission efficiency of a waveguide can be improved more.
Further, the via forming the third surrounding portion is preferably arranged on an extension of the inner wall of the waveguide.

  That is, the conversion portion does not have an end face for forming a hole, and even if a via is formed on the extension line of the inner wall of the waveguide, there is no problem that the strength of the substrate is lowered. That is, since the position corresponding to the end face can be directly grounded by the via forming the third surrounding portion, leakage of electromagnetic waves can be more efficiently prevented.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
FIG. 1A is a plan view showing a configuration of a dielectric substrate 1 according to a first embodiment to which the present invention is applied, and FIG.

  As shown in FIG. 1, the dielectric substrate 1 of this embodiment has a thickness in which conductor layers 3 and 5 (a ground pattern, a signal line pattern, etc.) made of a conductive material (eg, a metal thin film) are formed on both sides thereof. It is a double-sided substrate having a thickness d (d = 100 μm in this embodiment), and has the same inner diameter as a waveguide used for transmission of electromagnetic waves in a predetermined frequency band (75 to 110 GHz band in this embodiment). A rectangular hole H having (in this embodiment, 2.54 mm × 1.27 mm) is formed. In FIG. 1, the length in the thickness direction of the substrate is exaggerated (larger than actual) for easy understanding of the drawing.

  In addition, the dielectric substrate 1 has a plurality of vias (Via) 7 for conducting the conductor layers 3 and 5 at a position away from the end face 9 forming the inner wall of the hole H by a certain distance (via shift amount) δ. They are formed at intervals W. Hereinafter, the via 7 group is referred to as a first surrounding portion.

  However, assuming that the wavelength in the substrate in the dielectric substrate 1 at the frequency f of the transmission signal is λg, δ = λg / 2 and W ≦ λg / 4 are set. Specifically, in this embodiment, f = 76.5 GHz, and δ = 0.65 mm and W = 0.4 mm are set.

  The thus configured dielectric substrate 1 does not require a conductor layer to be formed on the end face 9, and therefore can be manufactured according to the general design rules of the dielectric substrate, thereby forming a waveguide at a low cost. can do.

  Moreover, the dielectric substrate 1 can use the hole H as a waveguide by grounding the conductor layers 3 and 5 that are electrically connected to the via 7. Moreover, since the end face 9 of the dielectric substrate 1 forming the inner wall of the waveguide (hole H) is separated from the grounded via 7 by λg / 2, it can be treated as being virtually short-circuited. In addition, since the interval between the vias 7 forming the first surrounding portion is set to λg / 4 or less that can efficiently suppress the leakage of electromagnetic waves from between the vias 7, A wave tube can be formed.

  Here, FIG. 2A is a graph showing a result obtained by simulation of the transmission characteristic S21 of the waveguide constituted by the dielectric substrate 1 while changing the via shift amount δ (50 μm to 1 mm). . As is apparent from the figure, the loss is small in the vicinity of λg / 2 (= 0.65 mm).

  FIG. 2B is a graph showing the results obtained by simulation of the transmission characteristic S21 of the waveguide constituted by the dielectric substrate 1 while changing the substrate thickness d (100 μm to 500 μm). Here, only the substrate thickness d is changed on the basis of what is designed to obtain optimum characteristics when the substrate thickness d = 100 μm. As can be seen from the figure, even when the substrate thickness is changed by a factor of 5, the increase in loss is 0.05 dB or less, and the loss hardly changes even when the substrate thickness d is changed.

  In the present embodiment, an example in which the present invention is applied to the dielectric substrate 1 composed of a single-sided double-sided substrate has been shown. However, as shown in FIG. The present invention may be applied. In this case, what is necessary is just to manufacture so that each layer which comprises the dielectric substrate 10 may have the structure similar to the above-mentioned dielectric substrate 1. FIG.

  Further, when the multilayer dielectric substrate 10 is formed, the multilayer dielectric substrate 10 may be formed from the beginning to be a multilayer substrate, or a single layer of the dielectric substrate 1 manufactured individually may be integrated later to form the multilayer substrate. You may make it. In particular, when the multilayer substrate is manufactured from the beginning, it is desirable that the via 7 is configured to penetrate each layer in a straight line in order to facilitate the manufacturing.

  Further, as in the dielectric substrate 1a shown in FIG. 9, the conductor is placed at a position that further surrounds the via 7 forming the first surrounding portion (a position separated from the via 7 by γ (≦ λg / 2) to the outer peripheral side). A plurality of vias 8 for conducting the layers 3 and 5 are formed at the same constant interval W as the vias 7. 9A is a plan view, and FIG. 9B is a cross-sectional view taken along line AA. Hereinafter, the via 8 group is referred to as a second surrounding portion.

Here, the interval between the vias 8 is set to the same W as the interval between the vias 7, but may be set to a size different from the interval between the vias 7 as long as it is λg / 4 or less. In FIG. 9A, the vias 7 and 8 are arranged so that the vertical positions and the horizontal positions coincide with each other, but they may be arranged so as to be shifted from each other.
[Second Embodiment]
Next, FIG. 4A is a perspective view showing the overall configuration of the transmission line converter 20 of the second embodiment to which the present invention is applied, and FIG. 4B is a sectional view taken along line BB.

  As shown in FIG. 4, the transmission line converter 20 includes three dielectric layers P1 to P3 and four pattern layers L1 to L4 formed so as to sandwich the three dielectric layers P1 to P3. It consists of a multilayer substrate having

  In the following, the dielectric layer P1 and the pattern layers L1 and L2 formed on both surfaces thereof are referred to as a conversion unit 20a, and the dielectric layers P2 and P3 and the pattern layers L2 to L4 formed between and both surfaces thereof. Is referred to as a waveguide forming portion 20b.

  The transmission line converter 20 is formed with a rectangular counterbore 21 that penetrates the central portion of the waveguide forming portion 20b and has the conversion portion 20a as a bottom surface. Further, a waveguide G communicating with the counterbore 21 is fixed to the waveguide forming portion 20b on the surface opposite to the conversion portion 20a side (that is, the formation surface of the pattern layer L4). The counterbore 21 is configured to have the same inner diameter as the waveguide G.

  Specifically, in this embodiment, a waveguide G having an inner diameter of 2.54 mm × 1.27 mm used for transmission of electromagnetic waves in the 75 to 110 GHz band is assumed to transmit a high-frequency signal having a frequency f = 76.5 GHz. Is used.

  The waveguide forming portion 20b penetrates the dielectric layers P2 and P3 at a position away from the end faces of the dielectric layers P2 and P3 formed by the counterbore 21 by a preset via shift amount δ, A plurality of vias 23 for connecting the pattern layers L2, L3, and L4 to each other are provided so as to surround the opening formed by the counterbore 21. Hereinafter, the via 23 group is referred to as a first surrounding portion.

  Further, in the same way as the via 23, the dielectric layer P2 and P3 are penetrated to the outer position of the via 23 forming the first surrounding portion (position further away from the end faces of the dielectric layers P2 and P3). A plurality of vias 24 for connecting the pattern layers L2, L3, and L4 to each other are provided so as to surround the first surrounding portion. Hereinafter, the via 24 group is referred to as a second surrounding portion.

  Further, in the conversion portion 20a, a plurality of vias 25 penetrating the dielectric layer P1 and electrically connecting the pattern layers L1 and L2 surround a portion facing the opening by the counterbore 21 and form a first surrounding portion. It is provided at a position closer to the end face of the counterbore 21 than the via 23 to be used. Hereinafter, the via 25 group is referred to as a third surrounding portion.

  The intervals between the vias 23 forming the first surrounding portion, the vias 24 forming the second surrounding portion, and the vias 25 forming the third surrounding portion are the substrates of the electromagnetic wave transmitted through the waveguide G. The inner wavelength is set to λg, and both are set to a constant interval W (≦ λg / 4). The via shift amount δ defining the position of the via 23 is set to n × λg / 2 where n is a positive integer. In this embodiment, n = 1 and δ = 0.65 mm. Has been. Further, the interval between the row of vias 23 forming the first surrounding portion and the row of vias 24 forming the second surrounding portion is set to λg / 2 or less.

Here, FIG. 5 is explanatory drawing which shows the shape of each pattern layer L1-L4.
As shown in FIG. 5, the pattern layer L4 formed on the surface of the dielectric layer P3 on the side to which the waveguide G is fixed is composed of a ground pattern GP4 that covers the entire surface excluding the opening due to the counterbore 21, and The pattern layer L3 formed between the layers P2 and P3 is composed of a ground pattern GP3 that covers the whole other than the inside of the via 23.

  Further, the pattern layer L2 formed between the dielectric layers P1 and P2, that is, between the conversion portion 20a and the waveguide forming portion 20b, covers the entire surface excluding the opening due to the counterbore 21, similarly to the pattern layer L4. It consists of a ground pattern GP2 and a rectangular antenna pattern AP located at the bottom of the counterbore 21.

  Furthermore, the pattern layer L1 formed on the surface facing the outer side of the dielectric layer P1 transmits a high-frequency signal, and is a planar line (strip line, wired) so that one end faces the antenna pattern AP of the pattern layer L2. The microstrip line, the coplanar line, etc.) SP and the planar line SP are non-contact, and the ground pattern GP1 is arranged so as to close the region corresponding to the opening by the counterbore 21. The via 25 forming the third surrounding portion is formed so that only the ground pattern GP1 of the pattern layer L1 is electrically connected to the ground pattern GP2 of the pattern layer L2. The planar line SP and the antenna pattern AP may be electrically connected by vias or the like.

  That is, in the transmission line converter 20, the waveguide forming portion 20b has the same structure as that obtained by stacking the two dielectric substrates 1a described as the modification of the first embodiment. A waveguide integrated with the waveguide G fixed to the vessel 20 is formed.

  Further, the conversion unit 20a is configured so as to block one end of the waveguide formed by the waveguide forming unit 20b, and the antenna pattern AP electromagnetically coupled to the planar line SP is positioned within the opening of the waveguide. Has been. The shape, position, and size of the antenna pattern AP are designed to be optimum values that minimize the conversion loss based on the frequency f of the high-frequency signal (electromagnetic wave) to be transmitted, the thickness d of the dielectric layer P1, and the like. The

  In the transmission line converter 20 configured as described above, the via shift amount δ from the end faces of the dielectric layers P2 and P3 formed by the counterbore 21 (that is, the inner wall of the waveguide formed by the waveguide forming portion 20b). A plurality of grounded vias 23 forming a first surrounding portion are arranged at positions separated by (= λg / 2), and the end face is formed as a virtual short-circuited surface. A plurality of grounded vias 24 that form a second surrounding portion are disposed at a position surrounding the portion, and the first surrounding portion and the second surrounding portion doubly prevent leakage of electromagnetic waves. .

Therefore, according to the transmission line converter 20, the loss of the waveguide formed by the waveguide forming part 20b can be suppressed to be small, and the conversion efficiency of the transmission line converter 20 can be improved.
In the transmission line converter 20, the third surrounding portion is also formed in the conversion portion 20 a at a position surrounding the portion facing the opening by the counterbore 21 (that is, the waveguide formed by the waveguide forming portion 20 b). Since the grounded via 25 is disposed, leakage of electromagnetic waves from the converter 20a can be prevented.

  Moreover, since the counterbore 21 is not formed in the conversion portion 20a, there is a problem that the strength of the substrate is deteriorated no matter how close the via 25 forming the third surrounding portion is to the end face. Instead, it can be arranged closer to the end face than the via 23 forming the first surrounding portion. As a result, it is possible to prevent leakage of electromagnetic waves more efficiently than the first surrounding portion.

Note that the characteristics of the waveguide formed by the waveguide forming portion 20b do not change greatly even if the thickness d of each of the dielectric layers P1 to P3 is changed as described in the first embodiment. In designing the conversion unit 20a, the thicknesses of the dielectric layers P1 to P3 can be arbitrarily selected, and the degree of design freedom can be increased.
[Third Embodiment]
Next, a third embodiment will be described.

6A is a perspective view showing the overall configuration of the transmission line converter 30 according to the third embodiment, and FIG. 6B is a cross-sectional view taken along the line CC in FIG.
Similar to the transmission line converter 20 of the second embodiment, the transmission line converter 30 of the present embodiment includes a conversion unit 30a and a waveguide forming unit 30b. However, since the waveguide forming portion 30b has the same configuration as that of the waveguide forming portion 30b of the second embodiment, description thereof will be omitted here, and description will be made focusing on the conversion portion 30a having a different configuration. .

As shown in FIG. 6, the conversion unit 30a includes a dielectric layer P1 and pattern layers L1 and L2 formed on both surfaces thereof.
Of these, the pattern layer L2 is composed of the ground pattern GP2 formed on the entire surface except for the bottom portion of the counterbore 21, that is, the antenna pattern AP is omitted as compared with the case of the second embodiment. It has become.

  On the other hand, the pattern layer L <b> 1 has a planar line SP that is wired so that one end is located at a part corresponding to the center of the bottom surface of the counterbore 21, a non-contact with the plane line SP, and a part corresponding to the bottom surface of the counterbore 21. The ground pattern GP1 is formed so as to cover the periphery.

  A plurality of vias 25 that penetrate the dielectric layer P1 and connect the ground pattern GP1 of the pattern layer L1 and the ground pattern GP2 of the pattern layer L2 to each other are formed in the conversion unit 30a. The portion of the dielectric layers P2 and P3 formed by the counterbore 21 is positioned on an extension line that surrounds the portion facing the waveguide formed by the waveguide forming portion 30b. It is provided to do. Hereinafter, the via 25 group is referred to as a third surrounding portion.

  In addition, a short-circuiting waveguide GT that short-circuits the end of the waveguide is fixed to the ground pattern GP1. However, the planar line SP is configured to be located at a position separated from the short-circuited end of the short-circuiting waveguide GT by ¼ of the wavelength in the waveguide of the transmission signal. However, it does not need to be exactly 1/4, and may be shifted within a range of about ± 20%.

The transmission line converter 30 of the present embodiment configured as described above can obtain the same configuration as that of the transmission line converter 20 of the second embodiment, except that the configuration of the conversion unit 30a is different.
Further, in the transmission line converter 30, the via 25 forming the third surrounding portion is disposed so as to be located on the extension line of the end face, so that electromagnetic wave leakage at the conversion portion 30 a is suppressed to the maximum. Can do.
[Other Embodiments]
As mentioned above, although several embodiment of this invention was described, this invention is not limited to the said embodiment, In the range which does not deviate from the summary of this invention, it is possible to implement in various aspects. .

  For example, in the above embodiment, the via shift amount is set to δ = λg / 2, but the present invention is not limited to this and may be an integral multiple of λg / 2. Further, the via shift amount δ is not necessarily exactly δ = n × λg / 2, and may be shifted within a range of about ± 20%.

  Further, in the second and third embodiments, the conversion units 20a and 30a are configured by one dielectric layer P1, but as illustrated in FIG. 7, the conversion units 20a and 30a are configured by a plurality of dielectric layers P11 and P12. (The figure shows a modification of the second embodiment).

In the second and third embodiments, the waveguide forming portions 20b and 30b are constituted by two dielectric layers P2 and P3, but are constituted by one or three or more dielectric layers. May be.
Further, as shown in FIG. 7, vias 25 forming the third surrounding portion provided in the conversion portion 20a are replaced with vias 23 forming the first and second surrounding portions provided in the waveguide forming portion 20b. Similarly to 24, it may be formed double. Furthermore, in this case, both of the double vias 25 are positioned closer to the counterbore 21 than the vias 23 (that is, positions of λg / 2 or less from the end face of the waveguide formed by the waveguide forming portion 20b). It is desirable to form. In particular, it is desirable to form the inner via 25 so as to be located on the extended line of the end face.

(A) is a top view which shows the structure of the dielectric substrate of 1st Embodiment, (b) is sectional drawing which shows the AA cross section. It is a graph which shows the result of having calculated | required the transmission characteristic of the waveguide which a dielectric material substrate forms by simulation, (a) is a case where the amount of via shifts (delta) is changed, (b) is a case where the board thickness d is changed. is there. Explanatory drawing which shows the structure which laminated | stacked the dielectric substrate of 1st Embodiment. (A) is a perspective view which shows the structure of the transmission line converter of 2nd Embodiment, (b) is sectional drawing which shows the BB cross section. Explanatory drawing which shows the structure of each pattern layer. (A) is a perspective view which shows the structure of the transmission line converter of 3rd Embodiment, (b) is sectional drawing which shows the CC cross section. Explanatory drawing which shows the structure of the modification of the transmission line converter of 2nd Embodiment. Explanatory drawing which shows the structure of a prior art, and a problem. (A) is a top view which shows the structure of the dielectric substrate of the modification of 1st Embodiment, (b) is sectional drawing which shows the AA cross section.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 1a, 10 ... Dielectric board | substrate, 3, 5 ... Conductor layer, 7, 8, 23, 24, 25 ... Via, 9 ... End face, 20, 30 ... Transmission line converter, 20a, 30a ... Conversion part, 20b 30b ... waveguide forming part, 21 ... borehole, H ... hole, G ... waveguide, GT ... waveguide for short circuit, AP ... antenna pattern, GP1 to GP4 ... ground pattern, SP ... planar line, L1 L4 ... pattern layer, P1-P3, P11, P12 ... dielectric layer.

Claims (11)

A dielectric substrate having a hole used as a waveguide,
A dielectric comprising: a first surrounding portion including a plurality of vias which surrounds an end face of the hole forming the inner wall of the waveguide and is disposed at a position where the end face is a virtual short-circuit surface. Body substrate. The wavelength in the substrate of the electromagnetic wave propagating through the waveguide is λg,
2. The dielectric substrate according to claim 1, wherein the via forming the first surrounding portion is located at a distance of n × λg / 2 (where n is a positive integer) from the end face. The wavelength in the substrate of the electromagnetic wave propagating through the waveguide is λg,
The dielectric substrate according to claim 1, wherein an arrangement interval of vias forming the first surrounding portion is λg / 4 or less.   4. The dielectric substrate according to claim 1, further comprising a second surrounding portion including a plurality of vias arranged at a position surrounding the first surrounding portion. 5. The wavelength in the substrate of the electromagnetic wave propagating through the waveguide is λg,
The dielectric substrate according to claim 4, wherein an interval between vias forming the second surrounding portion is λg / 4 or less. The wavelength in the substrate of the electromagnetic wave propagating through the waveguide is λg,
6. The dielectric substrate according to claim 4, wherein an interval between the first surrounding portion and the second surrounding portion is λg / 2 or less.   A waveguide comprising a plurality of the dielectric substrates according to claim 1 laminated together.   The waveguide according to claim 7, wherein the via is formed so as to penetrate the plurality of stacked dielectric substrates in a straight line. A waveguide forming part having a structure in which one or a plurality of the dielectric substrates according to claim 1 are laminated;
A planar line that is laminated on the waveguide forming part so as to block one end of the waveguide formed by the waveguide forming part, and transmits an electromagnetic wave, and the plane located in the opening of the waveguide A conversion unit comprising a dielectric substrate on which an antenna pattern electromagnetically coupled to the line is formed;
A transmission line converter comprising:   The transmission line converter according to claim 9, wherein the converter is provided with a third surrounding portion including a plurality of vias at a position surrounding a portion facing the opening of the waveguide.   The transmission line converter according to claim 10, wherein the via forming the third surrounding portion is disposed on an extension line of the inner wall of the waveguide.