JP2018107746A - Insulated waveguide - Google Patents

Abstract

An object of the present invention is to provide a heat insulating waveguide that can achieve both low loss and low heat inflow. A heat insulating waveguide according to an embodiment has a substrate, a first conductor line, a second conductor line, and a third conductor line. The first conductor line extends from one end of the substrate to the other end. The second conductor line and the third conductor line are different in position in the thickness direction of the substrate from the first conductor line, and extend in the width direction from one end of the substrate to the other end. They are spaced apart. The first conductor line is at a position overlapping at least a part of the gap between the second conductor line and the third conductor line when viewed from a direction perpendicular to the substrate. [Selection] Figure 1

Description

  Embodiments described herein relate generally to a heat insulating waveguide.

Conventionally, there is a waveguide using a planar circuit board as a connection structure for transmitting a signal such as a high frequency between two points having different temperatures. The waveguide may be required to have heat insulation performance.
In the waveguide, heat inflow can be suppressed and the heat insulation performance can be improved by reducing the area of the ground layer, but in this case, there is a possibility that the amount of signal passing loss may increase due to electromagnetic field radiation.

Japanese Patent No. 4236408

  The problem to be solved by the present invention is to provide an adiabatic waveguide that can achieve both low loss and low heat inflow.

  The heat insulating waveguide of the embodiment has a substrate, a first conductor line, a second conductor line, and a third conductor line. The first conductor line extends from one end of the substrate to the other end. The second conductor line and the third conductor line are different in position in the thickness direction of the substrate from the first conductor line, and extend in the width direction from one end of the substrate to the other end. They are spaced apart. The first conductor line is at a position overlapping at least a part of the gap between the second conductor line and the third conductor line when viewed from a direction perpendicular to the substrate.

(A) The top view which shows one surface of the heat insulation waveguide of embodiment. (B) The top view which shows the other surface of the heat insulation waveguide of embodiment. It is sectional drawing of the heat insulation waveguide of embodiment, Comprising: The figure which shows the II cross section of Fig.1 (a). (A) The top view which shows one surface of the 1st modification of the heat insulation waveguide of embodiment. (B) The top view which shows the other surface of the 1st modification of the heat insulation waveguide of embodiment. It is sectional drawing of the heat insulation waveguide of a 1st modification, Comprising: The figure which shows the II-II cross section of Fig.3 (a). (A) The top view which shows one surface of the 2nd modification of the heat insulation waveguide of embodiment. (B) The top view which shows the other surface of the 2nd modification of the heat insulation waveguide of embodiment. The figure which shows typically the heat insulation waveguide of the 3rd modification of the heat insulation waveguide of embodiment. The figure which shows the relationship between heat inflow amount and loss amount. The figure which shows the relationship between the ratio of the gap of a ground line with respect to the width | variety of a transmission line, and loss amount. (A) The figure which shows distribution of the current intensity in one surface of the 1st example of a heat insulation waveguide. (B) The figure which shows distribution of the current intensity in the other surface of the 1st example of a heat insulation waveguide. (A) The figure which shows distribution of the current intensity in one surface of the 2nd example of a heat insulation waveguide. (B) The figure which shows distribution of the electric current intensity in the other surface of the 2nd example of a heat insulation waveguide. (A) The figure which shows distribution of the electric current intensity in one surface of the other example of a heat insulation waveguide. (B) The figure which shows distribution of the electric current intensity in the other surface of the other example of a heat insulation waveguide. (A) The top view which shows one surface of an example of the conventional heat insulation waveguide. (B) The top view which shows the other surface of an example of the conventional heat insulation waveguide.

  Hereinafter, the heat insulation waveguide of embodiment is demonstrated with reference to drawings.

  FIG. 1A is a plan view showing one surface of the heat insulating waveguide 100 of the embodiment. FIG.1 (b) is a top view which shows the other surface of the heat insulation waveguide 100 of embodiment. FIG. 2 is a cross-sectional view of the heat insulating waveguide 100 and is a cross-sectional view taken along the line II of FIG. Note that the plan view means viewing from a direction perpendicular to the dielectric substrate 101.

  As shown in FIGS. 1A and 1B, the heat insulating waveguide 100 includes a dielectric substrate 101, a transmission line 102, a first ground line 103a, and a second ground line 103b. .

The dielectric substrate 101 is made of a ceramic material such as alumina, for example. The dielectric substrate 101 is, for example, rectangular in plan view. The dielectric substrate 101 is an example of a “substrate”.
A direction along the length direction of the dielectric substrate 101 is referred to as a Y direction. A direction orthogonal to the Y direction in a plane along the first main surface 101a of the dielectric substrate 101 is referred to as an X direction.

  The heat insulating waveguide 100 can be used, for example, in an environment where one end 104a in the length direction of the dielectric substrate 101 is hotter than the other end 104b. That is, for example, the end portion 104a is disposed on the high temperature portion side, and the end portion 104b is disposed on the low temperature portion side. The end 104a may be referred to as a high temperature end 104a, and the end 104b may be referred to as a low temperature end 104b. The temperature difference between one end (the high temperature end 104a) and the other end (the low temperature end 104b) of the heat insulating waveguide 100 is, for example, 150 ° C. or more.

  As shown in FIGS. 1A and 2, the transmission line 102 is formed on the first main surface 101 a (one surface) of the dielectric substrate 101. The transmission line 102 is a film made of a conductive material such as metal. As said metal, gold | metal | money, copper, copper alloy etc. are preferable, for example. The transmission line 102 is an example of a “first conductor line”.

  The transmission line 102 is formed from the high temperature end 104 a to the low temperature end 104 b of the dielectric substrate 101. The transmission line 102 is formed along the length direction (Y direction) of the dielectric substrate 101 in the center of the width direction (X direction) of the dielectric substrate 101, for example, and has a certain width in the length direction. The width of the transmission line 102 (that is, the dimension in the X direction) is referred to as “width W”.

The transmission line 102 is in a position overlapping a gap 105 between ground lines 103a and 103b described later in plan view.
Note that the transmission line 102 shown in FIG. 1A and FIG. 2 and the like is entirely in a position overlapping the gap 105, but the transmission line may be in a position overlapping at least a part of the gap.

As shown in FIGS. 1B and 2, the first ground line 103 a and the second ground line 103 b are formed on the second main surface 101 b (the other surface) of the dielectric substrate 101. The first ground line 103a and the second ground line 103b are films made of a conductive material such as metal. As said metal, gold | metal | money, copper, copper alloy etc. are preferable, for example.
The first ground line 103a is an example of a “second conductor line”. The second ground line 103b is an example of a “third conductor line”.

  The first ground line 103a and the second ground line 103b are respectively formed from the high temperature end portion 104a to the low temperature end portion 104b of the dielectric substrate 101. The first ground line 103 a and the second ground line 103 b have, for example, a constant line width and are formed along the length direction (Y direction) of the dielectric substrate 101. The width directions of the first ground line 103a and the second ground line 103b coincide with the X direction.

The first ground line 103a and the second ground line 103b are formed apart from each other in the width direction (X direction) of the lines 103a and 103b. The first ground line 103a and the second ground line 103b are parallel to each other, and are formed in parallel on the second main surface 101b of the dielectric substrate 101.
Note that the first ground line 103a and the second ground line 103b may be formed along substantially the same direction, and may not be parallel to each other. For example, if the first ground line and the second ground line are both formed by connecting one end and the other end of the substrate, it can be said that they are formed along substantially the same direction.

  Since the first ground line 103a and the second ground line 103b are formed on the second main surface 101b of the dielectric substrate 101, the transmission line 102 formed on the first main surface 101a is different from that of the dielectric substrate 101. The position in the thickness direction is different.

  A gap 105 between the first ground line 103a and the second ground line 103b is a region between the first ground line 103a and the second ground line 103b in the second main surface 101b. The gap 105 is a rectangular region extending from the high temperature end 104a to the low temperature end 104b of the dielectric substrate 101. The gap 105 has a certain width in the length direction (X direction), for example. The dimension in the width direction (dimension in the X direction) of the gap 105 is referred to as “gap G”.

The first ground line 103a and the second ground line 103b are parallel to the transmission line 102, for example. The width of the first ground line 103a and the width of the second ground line 103b may be the same or different from each other.
The first ground line 103 a and the second ground line 103 b may be formed along substantially the same direction as the transmission line 102, and may not be parallel to the transmission line 102. For example, if the ground line and the transmission line are both formed by connecting one end and the other end of the substrate, the ground line is formed substantially along the same direction as the transmission line. It can be said.

As shown in FIG. 2, the inner side edges 103a1 and 103b1 (the opposite edges) of the first ground line 103a and the second ground line 103b are, for example, more outward than the side edges 102a and 102a of the transmission line 102. It is located near. That is, the inner side edge 103a1 of the ground line 103a is located closer to the −X direction than the side edge 102a1 of the transmission line 102 on the −X direction side. The inner side edge 103b1 of the ground line 103b is located closer to the + X direction than the side edge 102a2 of the transmission line 102 on the + X direction side.
The + X direction is a direction from the first ground line 103a toward the second ground line 103b in the X direction. The −X direction is opposite to the + X direction.

The distance L1 in the width direction (X direction) between the first ground line 103a and the transmission line 102 is preferably equal to the distance L2 in the width direction (X direction) between the second ground line 103b and the transmission line 102. .
The distance L1 is a distance in the X direction between the inner side edge 103a1 of the first ground line 103a and the side edge 102a1 on the −X direction side of the transmission line 102. The distance L2 is a distance in the X direction between the side edge 103b1 on the inner side of the second ground line 103b and the side edge 102a2 on the + X direction side of the transmission line 102.

According to the heat insulating waveguide 100 shown in FIGS. 1A, 1B, and 2, the transmission line 102 is positioned so as to overlap the gap 105 between the first ground line 103a and the second ground line 103b. Therefore, even when the area of the transmission line is small compared to the case where the entire transmission line overlaps the ground line, the loss can be suppressed low.
If the areas of the transmission line 102 and the ground lines 103a and 103b are reduced, the amount of heat inflow can be suppressed. Therefore, in the heat insulating waveguide 100, loss can be reduced and heat inflow can be suppressed. That is, the heat insulating waveguide 100 can achieve both low loss and low heat inflow.

In the heat insulating waveguide 100, it is possible to estimate the following that the loss can be suppressed even when the area of the line is small.
In the heat insulating waveguide 100, the transmission line 102 is at a position overlapping the gap 105 between the ground lines 103a and 103b. Therefore, the radiation of energy in the transmission line 102 and the ground lines 103a and 103b is suppressed by the bias of the current distribution at the line side edge due to the electrical interaction between the transmission line 102 and the ground lines 103a and 103b. Therefore, the loss can be suppressed even when the area of the line is small, compared to the case where the entire transmission line is in a position overlapping the ground line.

  In the heat insulation waveguide 100, since there is no defect | deletion location in the transmission line 102 and the ground lines 103a and 103b, it is advantageous when using a direct current. Therefore, it can respond also to supply of direct current to the circuit connected downstream.

Next, the 1st modification of the heat insulation waveguide 100 of embodiment is demonstrated. The common points with the heat insulating waveguide 100 are denoted by the same reference numerals and the description thereof is omitted.
FIG. 3A is a plan view showing one surface of a heat insulating waveguide 100 </ b> A that is a first modification of the heat insulating waveguide 100. FIG. 3B is a plan view showing the other surface of the heat insulating waveguide 100A. FIG. 4 is a cross-sectional view of the heat insulating waveguide 100A and is a cross-sectional view taken along the line II-II in FIG.

As shown in FIG. 3A, FIG. 3B, and FIG. 4, the heat insulating waveguide 100A is the same as that shown in FIG. 1A except that a missing portion 504 is formed in the intermediate portion 102d of the transmission line 102. The configuration is the same as that of the heat insulating waveguide 100 shown in FIGS.
The intermediate portion 102d is a portion between one end portion 102b and the other end portion 102c of the transmission line 102.

The defect portion 504 is a portion where there is no conductive film constituting the transmission line 102. In the defect portion 504, the first main surface 101a of the dielectric substrate 101 is exposed.
The defect part 504 is located inward from the side edges 102a and 102a of the transmission line 102, for example. That is, as shown in FIG. 4, the missing portion 504 is located closer to the + X direction than the side edge 102a1 of the transmission line 102 and closer to the −X direction than the side edge 102a2.

  As illustrated in FIG. 3A, the defect portion 504 is formed, for example, in the center in the width direction (X direction) of the transmission line 102 along the length direction (Y direction) of the transmission line 102. The defect portion 504 has a certain width in the length direction, for example. The planar view shape of the defect | deletion part 504 is a rectangular shape (for example, rectangle), for example. In addition, the planar view shape of a defect | deletion part is not specifically limited, For example, the elliptical shape which orient | assigned the major axis direction to the length direction of the track | line may be sufficient.

  In the heat insulating waveguide 100A, since the defect portion 504 is formed in the intermediate portion 102d having a low current intensity, the area of the transmission line 102 can be reduced without increasing the loss. Therefore, loss can be reduced and the amount of heat inflow can be further suppressed.

Next, the 2nd modification of the heat insulation waveguide 100 of embodiment is demonstrated. The common points with the heat insulating waveguide 100 are denoted by the same reference numerals and the description thereof is omitted.
FIG. 5A is a plan view showing one surface of a heat insulating waveguide 100B which is a second modification of the heat insulating waveguide 100. FIG. FIG. 5B is a plan view showing the other surface of the heat insulating waveguide 100B.

As shown in FIG. 5A and FIG. 5B, the heat insulating waveguide 100B is a narrow portion having a narrower width than the other portion 804a in the length direction of the transmission line 802 in the intermediate portion 802d of the transmission line 802. Except that 804b is formed, it is the same structure as the heat insulation waveguide 100 shown to Fig.1 (a), FIG.1 (b), and FIG.
The intermediate portion 802d is a portion between one end 802b and the other end 802c of the transmission line 802.
The narrow portion 804b is formed by forming notches in both side edges 802a and 802a. The narrow part 804b has a certain width in the length direction, for example.
The narrow portion 804b is formed by forming notches having the same width on both side edges 802a and 802a. Therefore, the position in the width direction (X direction) of the narrow portion 804 b is the center of the transmission line 802.

  In the heat insulating waveguide 100B, since the narrow portion 804b is formed in the intermediate portion 802d having low current intensity, the area of the transmission line 802 can be reduced without increasing the loss. Therefore, loss can be reduced and the amount of heat inflow can be further suppressed.

Next, the 3rd modification of the heat insulation waveguide 100 of embodiment is demonstrated. The common points with the heat insulating waveguide 100 are denoted by the same reference numerals and the description thereof is omitted.
FIG. 6 is a diagram schematically illustrating a heat insulating waveguide 100 </ b> C that is a third modification of the heat insulating waveguide 100.

As illustrated in FIG. 6, the heat insulating waveguide 100 </ b> C has the same configuration as the heat insulating waveguide 100 illustrated in FIGS. 1A, 1 </ b> B, and 2 except that the substrate 1001 is a flexible substrate.
The substrate 1001 is a flexible substrate made of, for example, a polyimide material.
Connection portions 1004a and 1004b are provided at both ends of the heat insulating waveguide 100C, respectively.
For example, the heat insulating waveguide 100C is bent at about 90 ° in the thickness direction at the bent portion 1003.

  In the heat insulating waveguide 100C, since the substrate 1001 is a flexible substrate, bending deformation in the thickness direction is possible. Therefore, the degree of freedom in mounting can be increased without increasing loss. Therefore, even if the connection portions 1004a and 1004b have a restriction on the installation position, the connection parts 1004a and 1004b can be installed at an appropriate position. Therefore, it is possible to reduce the size of the apparatus using the heat insulating waveguide 100C.

  Hereinafter, based on an Example, said embodiment is described further in detail.

First, Example 1 will be described.
Using the heat insulating waveguide 100 shown in FIGS. 1 (a), 1 (b) and 2, the loss (dB) and heat inflow (mW) were calculated when the center frequency was 9 GHz.
The thermal conductivity of the dielectric substrate 101 of the heat insulating waveguide 100 was 0.5 (W / m · K), the thickness was 0.1 mm, and the width was 2 mm.
The thickness of the metal film constituting the transmission line 102 and the ground lines 103a and 103b was 9 μm. The metal constituting the metal film was copper. The width of the transmission line 102 was 0.24 mm (50Ω line width in the microstrip line). The total line width of the ground lines 103a and 103b was 0.2 mm.
In this configuration, the loss at the center frequency is 0.32 dB, and the heat inflow is 31.7 mW. The results are shown in FIG.

Next, Comparative Example 1 will be described.
FIG. 12A is a plan view showing one surface of a heat insulating waveguide 200 which is an example of a conventional heat insulating waveguide. FIG. 12B is a plan view showing the other surface of the heat insulating waveguide 200.
The heat insulating waveguide 200 includes a dielectric substrate 201, a transmission line 202, and a ground line 203.
The transmission line 202 is formed on the first main surface 201 a (one surface) of the dielectric substrate 201. The transmission line 202 is at a position overlapping the ground line 203 in plan view.
The ground line 203 is formed on the second main surface 201b (the other surface) of the dielectric substrate 201. The ground line 203 is formed wider than the transmission line 202. The center line along the length direction of the ground line 203 overlaps the center line along the length direction of the transmission line 202 in plan view.

Using the adiabatic waveguide 200 shown in FIGS. 12A and 12B, the amount of loss (dB) and the amount of heat inflow (mW) were calculated when the center frequency was 9 GHz.
The thermal conductivity of the dielectric substrate 201 of the heat insulating waveguide 200 was 0.5 (W / m · K), the thickness was 0.1 mm, and the width was 2 mm.
The thickness of the metal film constituting the transmission line 202 and the ground line 203 was 9 μm. The metal constituting the metal film was copper. The width of the transmission line 202 was 0.24 mm (50Ω line width in the microstrip line).
When the width W1 of the ground line 203 is 0.2 mm, 0.75 mm, and 1.2 mm, the loss amounts at the center frequency are 0.50 dB, 0.26 dB, and 0.18 dB, respectively. The heat inflow amounts are 31.7 mW, 47.3 mW and 70.5 mW, respectively. The results are shown in FIG.

Next, Comparative Example 2 will be described.
Using a waveguide that is a coaxial cable, a loss amount (dB) and a heat inflow amount (mW) were calculated when the center frequency was 9 GHz.
The outer diameter of the central conductor (Cu) of the waveguide was 2.2 mm. The outer diameter of the intermediate layer (Cu) was 3.2 mm. The outer diameter of the outermost layer (CuNi) was 3.6 mm.
The loss amounts at the center frequency are 1.60 dB, 0.42 dB, and 0.25 dB, respectively. The heat inflow amounts are 78 mW, 357 mW, and 714 mW, respectively. The results are shown in FIG.

As shown in FIG. 7, in Example 1, compared with Comparative Examples 1 and 2, it is possible to achieve a low heat inflow amount with the same amount of loss and a low loss amount with the same amount of heat inflow.
From this, in Example 1, since loss can be suppressed by reducing the line area which becomes a factor of heat inflow, it turns out that low loss and low heat inflow can be made compatible.
Further, in the first embodiment, since there is no defect in the line, it is advantageous when a direct current is used. Therefore, it can respond also to supply of direct current to the circuit connected downstream.

  In the heat insulating waveguide 100 shown in the first embodiment, the width W of the transmission line 102 (see FIGS. 1A and 2) is constant, and the gap G between the ground lines 103a and 103b (see FIG. 1B and FIG. 2). ), The ratio of the gap G to the width W (G / W) was calculated. FIG. 8 shows the calculation result of the relationship between the ratio G / W and the loss amount. The center line in the width direction of the transmission line 102 and the center line in the width direction of the gap 105 were made to coincide in plan view.

From FIG. 8, the loss amount can be reduced by making the ratio G / W larger than 1.
As the ratio G / W increases up to a certain range, the bias of the current intensity decreases. However, if the ratio G / W increases too much, radiation loss may increase. Therefore, the loss amount as a whole may increase.
The loss amount can be further reduced by setting the ratio G / W to 2 or more. By setting the ratio G / W to 3.5 or less, the overall loss can be reduced. Therefore, the loss amount can be reduced by setting the ratio G / W to 2 to 3.5.

Next, Example 2 will be described.
Using the heat insulating waveguide 100A shown in FIGS. 3A, 3B, and 4, the loss (dB) and heat inflow (mW) were calculated when the center frequency was 9 GHz.
The second embodiment is the same as the first embodiment except that the missing portion 504 is formed at the center in the width direction of the transmission line 102.
Table 1 shows the calculation results of the loss and heat inflow at the center frequency in this configuration.

  From Table 1, it can be seen that in Example 2, the heat inflow amount can be lowered without increasing the loss amount as compared with Example 1.

Next, Example 3 will be described.
Using the heat insulating waveguide 100B shown in FIGS. 5A and 5B, the loss (dB) and heat inflow (mW) were calculated when the center frequency was 9 GHz.
The third embodiment is the same as the first embodiment except that the narrow portion 804b is formed in the intermediate portion 802d of the transmission line 802.
Table 2 shows the calculation results of the loss and heat inflow at the center frequency in this configuration.

  From Table 2, it can be seen that in Example 3, the amount of heat inflow can be reduced without increasing the amount of loss compared to Example 1.

Next, Example 4 will be described.
Using the heat insulating waveguide 100C shown in FIG. 6, the amount of loss (dB) was calculated when the center frequency was 9 GHz.
Example 3 was the same as Example 1 except that a flexible substrate 1001 was used as the substrate.
Table 3 shows the amount of loss at the central frequency when 90 ° bending is applied to the heat insulating waveguide 100C in this configuration and when bending is not applied (bending angle 0 °).

  From Table 3, it can be seen that in Example 4, even when bending is applied, a loss amount equivalent to that obtained when bending is not applied can be obtained.

  FIG. 9A is a diagram illustrating a distribution of current intensity on one surface (first main surface 101a) in the heat insulating waveguide 100D which is the first example of the heat insulating waveguide 100. FIG. FIG. 9B is a diagram showing the distribution of current intensity on the other surface (second main surface 101b) in the heat insulating waveguide 100D. In FIG. 9 (a) and FIG. 9 (b), the current intensity is represented by shading.

As shown in FIG. 9B, in the heat insulating waveguide 100D, the gap G (G1) between the ground lines 103a and 103b is relatively small. Therefore, the distance between the ground lines 103a and 103b and the transmission line 102 is small.
As shown in FIG. 9A, the current intensity is high in the portions near the end portions 102b and 102c of the side edges 102a and 102a of the transmission line 102.
As shown in FIG. 9 (b), the current intensity is close to the end portions 103a2, 103a3, 103b2, and 103b3 in the side edges 103a1 and 103b1 (edges facing each other) inside the ground lines 103a and 103b. It is high.

  FIG. 10A is a diagram showing a distribution of current intensity on one surface (first main surface 101a) in the heat insulating waveguide 100E which is the second example of the heat insulating waveguide 100. FIG. FIG. 10B is a diagram showing a current intensity distribution on the other surface (second main surface 101b) in the heat insulating waveguide 100E.

As shown in FIG. 10B, in the heat insulating waveguide 100E, the gap G (G2) between the ground lines 103a and 103b is relatively large. Therefore, the distance between the ground lines 103a and 103b and the transmission line 102 is larger than that of the heat insulating waveguide 100D shown in FIGS. 9A and 9B.
As shown in FIG. 10A, the current intensity is higher in the portions near the end portions 102b and 102c of the side edges 102a and 102a of the transmission line 102 than in the other portions. Compared with the transmission line 102 of the adiabatic waveguide 100D shown, the current intensity is small.
As shown in FIG. 10 (b), the current density is different at the side edges 103a1 and 103b1 (edges facing each other) inside the ground lines 103a and 103b and close to the ends 103a2, 103a3, 103b2, and 103b3. Compared with the ground lines 103a and 103b of the heat insulating waveguide 100D shown in FIG. 9B, the current density deviation is small.

  FIG. 11A is a diagram showing a current density distribution on one surface (first main surface 101a) in a heat insulating waveguide 100F as another example of the heat insulating waveguide. FIG. 11B is a diagram showing a current density distribution on the other surface (second main surface 101b) in the heat insulating waveguide 100F.

  The heat insulating waveguide 100F is an example in which the gap G between the ground lines 103a and 103b shown in FIGS. 9B and 10B is zero. Therefore, as shown in FIG. 11B, one ground line 103ab is formed on the second main surface 101b of the dielectric substrate 101 in place of the ground lines 103a and 103b.

As shown in FIGS. 9 (a) to 11 (b), the heat insulating waveguides 100D and 100E shown in FIGS. 9 (a) to 10 (b) are shown in FIGS. 11 (a) and 11 (b). The distribution of current density in the transmission line and the ground line is different from that of the heat insulating waveguide 100F.
In addition, compared to the heat insulating waveguide 100D (see FIGS. 9A and 9B), the heat insulating waveguide 100E (see FIGS. 10A and 10B) having a larger gap G has a current density. The bias is relatively small.

In the heat insulating waveguide 100 shown in FIG. 1A, FIG. 1B, and FIG. 2, the entire transmission line 102 is in a position overlapping the gap 105 in plan view, but a part of the transmission line 102 is grounded. It may overlap with the lines 103a and 103b.
In the heat insulating waveguide 100, as shown in FIG. 2, the distance L1 between the first ground line 103a and the transmission line 102 and the distance L2 between the second ground line 103b and the transmission line 102 are equal to each other. The distance L2 may not be the same.
In the adiabatic waveguide 100, the transmission line 102, the first ground line 103a, and the second ground line 103b are parallel to each other, but not limited thereto, the lines 102, 103a, and 103b include two or more of them. The track may not be parallel.

  The heat insulating waveguide 100 includes the two ground lines 103a and 103b, but the number of the ground lines only needs to be plural. For example, the heat insulating waveguide 100 may include three or more ground lines formed at intervals in the width direction. Good. In that case, the heat insulating waveguide has a plurality of gaps between the ground lines, but the transmission line may be located at a position overlapping at least a part of at least one of the plurality of gaps.

  In the heat insulating waveguide 100, the transmission line 102 and the ground lines 103a and 103b are formed on one and the other surfaces of the dielectric substrate 101, respectively. Accordingly, the transmission line 102 and the ground lines 103a and 103b are formed at different positions in the thickness direction of the dielectric substrate 101. In the heat insulating waveguide of the embodiment, the configuration in which the transmission line and the ground line are formed at different positions in the thickness direction of the substrate is not limited thereto. For example, a configuration in which one of the transmission line and the ground line is formed on the surface of the substrate and the other is embedded in the substrate is also possible.

  In the heat insulating waveguide 100 shown in FIG. 2, the side edges 103a1 and 103b1 inside the ground lines 103a and 103b are more outward than the side edges 102a and 102a of the transmission line 102 over the entire length in the width direction (X direction). However, only a part of the side edges 103a1 and 103b1 in the length direction may be located outward from the side edges 102a and 102a of the transmission line 102.

  The side edges 103a1 and 103b1 of the ground lines 103a and 103b are preferably located outward from the side edges 102a and 102a of the transmission line 102 in a plan view, but are located at positions corresponding to the side edges 102a and 102a. Alternatively, it may be located inward from the side edges 102a, 102a.

In the heat insulating waveguide 100A shown in FIG. 3A, FIG. 3B, and FIG. 4, a defect 504 is formed only in the transmission line 102 of the transmission line 102 and the ground lines 103a and 103b. The heat insulating waveguide of the embodiment is not limited to this, and may have a configuration in which a defective portion is formed in at least one of the transmission line and the ground line. For example, a defective portion may be formed in one or both of the first ground line and the second ground line.
In the heat insulating waveguide 100A, the position in the width direction (X direction) of the defect portion 504 is the center of the transmission line 102. However, the position in the width direction of the defect portion in the transmission line is not limited to this, The position may be shifted in the direction.

In the heat insulating waveguide 100B shown in FIGS. 5A and 5B, the narrow portion 804b is formed only in the transmission line 802 of the transmission line 802 and the ground lines 103a and 103b. The heat insulating waveguide of the embodiment is not limited to this, and may have a configuration in which a narrow portion is formed in at least one of the transmission line and the ground line. For example, a narrow portion may be formed on one or both of the first ground line and the second ground line.
In the heat insulating waveguide 100B, the position in the width direction (X direction) of the narrow portion 804b is the center of the transmission line 802, but the position in the width direction of the narrow portion in the transmission line is not limited to this. The position may be shifted in the X direction.

  According to at least one embodiment described above, since the transmission line 102 is positioned so as to overlap the gap 105 between the first ground line 103a and the second ground line 103b, loss can be reduced and heat inflow can be suppressed. .

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

100, 100A, 100B, 100C ... adiabatic waveguide, 101 ... dielectric substrate, 102 ... transmission line, 102d, 802d ... middle part, 103a ... first ground line 103a (second conductor line), 103b ... second ground line 103b (third conductor line), 104a ... end (one end), 104b ... end (the other end), 105 ... gap, 804b ... narrow part, 1001 ... flexible substrate.

Claims (6)

A substrate,
A first conductor line extending from one end of the substrate to the other end;
A second conductor line and a third conductor line which are different from each other in the thickness direction of the substrate from the first conductor line and are spaced apart in the width direction from one end of the substrate to the other end. A conductor line,
The adiabatic waveguide, wherein the first conductor line is located at a position overlapping at least a part of a gap between the second conductor line and the third conductor line when viewed from a direction perpendicular to the substrate.   2. The heat insulating waveguide according to claim 1, wherein a gap between the second conductor line and the third conductor line is wider than a width of the first conductor line.   The heat insulating waveguide according to claim 2, wherein a ratio G / W of a gap G between the second conductor line and the third conductor line and a width W of the first conductor line is 2 to 3.5.   The adiabatic waveguide according to any one of claims 1 to 3, wherein the first conductor line has a defective portion at an intermediate portion between the one end portion and the other end portion.   At least one of the first conductor line, the second conductor line, and the third conductor line has a width that is narrower than at least a part of another part in which the position in the length direction of the conductor line is different. The heat insulation waveguide of any one of Claims 1-4 which has a narrow part.   The heat insulation waveguide according to any one of claims 1 to 5, wherein the substrate is a flexible substrate.