WO2018100714A1 - Waveguide directional coupler and method for making waveguide directional coupler - Google Patents

Abstract

A waveguide directional coupler in which a cross-sectional shape of a transformation waveguide (24a-24d) perpendicular to a waveguide-axis direction is a cutout shape obtained by cutting out the two corners on one diagonal line in a quadrangle. In the cutout shape, a first area that is longer in a waveguide-width direction than in a waveguide-height direction is connected to a connection waveguide (23a-23d) or to an input/output waveguide (25a-25d). In the cutout shape, a second area that is shorter in the waveguide-width direction than in the waveguide-height direction is connected to the input/output waveguide (25a-25d) or to the connection waveguide (23a-23d).

Description

Waveguide directional coupler and method for manufacturing waveguide directional coupler

The present invention relates to a waveguide directional coupler that inputs and outputs power and a method for manufacturing the waveguide directional coupler.

For example, an antenna feeding circuit for satellite communication, satellite control, or the like may be equipped with a polarization separation / combination circuit that separates or combines two orthogonal polarizations. In addition, the polarization separation / combination circuit may be equipped with a waveguide directional coupler that inputs and outputs power.
A branch line coupler is known as a waveguide directional coupler used in a polarization splitting / combining circuit.

The branch line coupler disclosed in Non-Patent Document 1 below is arranged so that the wide wall surfaces of the two input / output waveguides face each other, and the wide wall surfaces of the two input / output waveguides are thin branches. Connected by a branch.
When the waveguide directional coupler equipped with this branch line coupler is mounted on the polarization splitting / synthesizing circuit, the interference between other waveguides is avoided because the wide walls of the two input / output waveguides face each other. The layout can be realized relatively easily. Moreover, the exclusive cross-sectional area seen from the antenna can be made small.

A Review of Multibeam Antenna Solutions and their Applications

Since the conventional waveguide directional coupler is configured as described above, a layout that avoids interference with other waveguides can be realized relatively easily. However, when a waveguide directional coupler is to be formed by combining a plurality of metal blocks cut by an end mill for the purpose of reducing the processing cost, the metal block is also pre-installed for the branch line coupler. It is necessary to cut it.
However, when a plurality of metal blocks constituting the branch line coupler are cut using a drill having a small drill diameter, the length that can be drilled by the drill is short, so that the desired position may not be drilled. In addition, since the amount that can be dug at a time is small, it may take a long time to complete the cutting process.
On the other hand, when cutting a plurality of metal blocks constituting a branch line coupler using a drill having a large drill diameter, it is difficult to cut fine portions with high precision. There has been a problem that the reflection characteristics may deteriorate.

The present invention has been made to solve the above-described problems. It is an object of the present invention to obtain a waveguide directional coupler that does not cause deterioration of reflection characteristics even when the drill diameter of the drill is increased. To do.
Another object of the present invention is to obtain a manufacturing method capable of obtaining the above-described waveguide directional coupler.

A waveguide directional coupler according to the present invention includes a metamorphic waveguide having one end connected to a connection waveguide and the other end connected to an input / output waveguide. The cross-sectional shape perpendicular to the square is a notch shape in which two corners on one diagonal line in the quadrangle are notched, and the length in the tube width direction is the length in the tube height direction in the notch shape. The first region longer than the length is connected to the connection waveguide or the input / output waveguide, and in the cutout shape, the second region whose length in the tube width direction is shorter than the length in the tube height direction is inserted. It is designed to be connected to an output waveguide or a connection waveguide.

According to this invention, the shape of the cross section perpendicular to the tube axis direction in the metamorphic waveguide is a notch shape in which two corners on one diagonal line in the quadrangle are notched, Then, the first region whose length in the tube width direction is longer than the length in the tube height direction is connected to the connection waveguide or the input / output waveguide, and the length in the tube width direction is within the cutout shape. Since the second region shorter than the length in the pipe height direction is connected to the input / output waveguide or the connection waveguide, the drill diameter is small even if the drill diameter of the drill used for processing is increased. There is an effect that it is possible to obtain a reflection characteristic equivalent to that when a drill is used. In addition, there is an effect that the tube axis direction becomes small.

1 is a perspective view showing a waveguide directional coupler according to Embodiment 1 of the present invention. It is a perspective view which shows the connection waveguide 23c, the transformation waveguide 24c, and the input-output waveguide 25c of the waveguide directional coupler by Embodiment 1 of this invention. FIG. 6 is a transmission diagram showing a yz section in a connection waveguide 23c, a transformation waveguide 24c, and an input / output waveguide 25c. It is a perspective view which shows a short slot coupler. 1 is a perspective view showing a branch line coupler disclosed in Non-Patent Document 1. FIG. It is explanatory drawing which shows the manufacturing method of the waveguide directional coupler by Embodiment 1 of this invention. It is explanatory drawing which shows the manufacturing method of the waveguide directional coupler by Embodiment 1 of this invention. It is a perspective view which shows the other waveguide directional coupler by Embodiment 1 of this invention. It is explanatory drawing which shows the manufacturing method of the other waveguide directional coupler by Embodiment 1 of this invention. It is explanatory drawing which shows the manufacturing method of the other waveguide directional coupler by Embodiment 1 of this invention. FIG. 6 is a transmission diagram showing a yz section in a connection waveguide 23c, a transformation waveguide 24c, and an input / output waveguide 25c. FIG. 6 is a transmission diagram showing a yz section in a connection waveguide 23c, a transformation waveguide 24c, and an input / output waveguide 25c. FIG. 13A is an explanatory view showing the dimensions of the waveguide A of the short slot coupler, and FIG. 13B is an explanatory view showing the position where the electric field is strongest at the input / output end (D1 cross section) and the position near the center (D2 cross section). FIG. It is explanatory drawing which shows the electromagnetic field calculation result of the axial ratio in a waveguide directional coupler. It is explanatory drawing which shows the electromagnetic field calculation result of the reflective characteristic in a waveguide directional coupler. FIG. 6 is a transmission diagram showing a yz section in a connection waveguide 23c, a transformation waveguide 24c, and an input / output waveguide 25c.

Hereinafter, in order to explain the present invention in more detail, modes for carrying out the present invention will be described with reference to the accompanying drawings.

Embodiment 1 FIG.
1 is a perspective view showing a waveguide directional coupler according to Embodiment 1 of the present invention.
The waveguide directional coupler of FIG. 1 is mounted on, for example, a polarization separation / synthesis circuit.
In FIG. 1, the x direction is the tube axis direction, the y direction is the tube width direction, and the z direction is the tube height direction.
The central waveguide 21 has a width about twice that of the connection waveguide 23a. The central waveguide 21 has a TE10 mode and a TE20 mode as a waveguide having a width about twice that of the connection waveguide 23a.

The branching waveguide 22a has a first tube port connected to one end of the central waveguide 21, and a second tube port and a third tube port on the opposite side of the first tube port in the x direction. It is the 1st branching waveguide which has.
In the example of FIG. 1, the first tube port of the branching waveguide 22a is on the + x direction side, and the second tube port and the third tube port of the branching waveguide 22a are on the −x direction side.
Further, the length of the branching waveguide 22a in the y direction is longer than the length of the central waveguide 21 in the y direction, and the length of the branching waveguide 22a in the z direction is equal to the z direction of the central waveguide 21. It is longer than the length of.

The branch waveguide 22b has a first tube port connected to the other end of the central waveguide 21, and a second tube port and a third tube port on the opposite side to the first tube port in the x direction. A second branching waveguide having
In the example of FIG. 1, the first tube port of the branch waveguide 22b is on the −x direction side, and the second tube port and the third tube port of the branch waveguide 22a are on the + x direction side.
The length of the branch waveguide 22b in the y direction is longer than the length of the central waveguide 21 in the y direction, and the length of the branch waveguide 22b in the z direction is equal to the z direction of the central waveguide 21. It is longer than the length of.

The connection waveguide 23a is a first connection waveguide whose one end is connected to the second tube port of the branch waveguide 22a.
The connection waveguide 23b is a second connection waveguide having one end connected to the third tube port in the branch waveguide 22a.
The connection waveguide 23c is a third connection waveguide having one end connected to the second tube port in the branch waveguide 22b.
The connection waveguide 23d is a fourth connection waveguide having one end connected to the third tube port in the branch waveguide 22b.

The metamorphic waveguide 24a is a first metamorphic waveguide whose one end is connected to the other end of the connection waveguide 23a.
The metamorphic waveguide 24b is a second metamorphic waveguide whose one end is connected to the other end of the connection waveguide 23b.
The metamorphic waveguide 24c is a third metamorphic waveguide whose one end is connected to the other end of the connection waveguide 23c.
The modified waveguide 24d is a fourth modified waveguide whose one end is connected to the other end of the connection waveguide 23d.

The input / output waveguide 25a is a first input / output waveguide whose one end is connected to the other end of the modified waveguide 24a.
The input / output waveguide 25b is a second input / output waveguide whose one end is connected to the other end of the modified waveguide 24b.
In the example of FIG. 1, the wide wall surface 26 of the input / output waveguide 25a faces the wide wall surface 26 of the input / output waveguide 25b.

The input / output waveguide 25c is a third input / output waveguide whose one end is connected to the other end of the modified waveguide 24c.
The input / output waveguide 25d is a fourth input / output waveguide whose one end is connected to the other end of the modified waveguide 24d.
In the example of FIG. 1, the wide wall surface 26 of the input / output waveguide 25c and the wide wall surface 26 of the input / output waveguide 25d face each other.

FIG. 2 is a perspective view showing a connection waveguide 23c, a transformation waveguide 24c, and an input / output waveguide 25c of the waveguide directional coupler according to Embodiment 1 of the present invention.
FIG. 3 is a transmission diagram showing a yz section in the connection waveguide 23c, the transformation waveguide 24c, and the input / output waveguide 25c.
In FIG. 3, the dotted line indicates the cross-sectional shape of the metamorphic waveguide 24c.
The solid line indicates the cross-sectional shape of the connection waveguide 23c, and the broken line indicates the cross-sectional shape of the input / output waveguide 25c.
As shown in FIG. 3, the metamorphic waveguide 24c has a cross-sectional shape perpendicular to the x direction, that is, a yz cross-sectional shape, in which two corners on one diagonal of a quadrangle are cut off. It has a notch shape.
Among the cutout shapes in the metamorphic waveguide 24c, the first region whose length in the y direction is longer than the length in the z direction (the hatched region in FIG. 3) is the connection waveguide 23c. It is the 1st pipe port connected.
In addition, in the cutout shape of the transformation waveguide 24c, the second region (the shaded region in FIG. 3) in which the length in the y direction is shorter than the length in the z direction is the input / output guide. This is a second tube port connected to the wave tube 25c.
The central axis in the y direction in the connection waveguides 23a to 23d and the central axis in the y direction in the input / output waveguides 25a to 25d are coincident with each other, and ● represents the coincident central axis.

In FIG. 3, the dimension A which is the length in the y direction in the connection waveguide 23c is the same as the dimension A which is the length in the z direction in the input / output waveguide 25c, and z in the connection waveguide 23c. An example is shown in which the B dimension, which is the length in the direction, is the same as the B dimension, which is the length in the y direction in the input / output waveguide 25c.
2 and 3, the connection waveguide 23c, the transformation waveguide 24c, and the input / output waveguide 25c are illustrated. However, the connection waveguide 23a, the transformation waveguide 24a, and the input / output waveguide 25a are illustrated. This is the same as FIG. 2 and FIG.
The connection waveguide 23b, the transformation waveguide 24b, and the input / output waveguide 25b are the same as those in FIGS. 2 and 3, and the connection waveguide 23d, the transformation waveguide 24d, and the input / output waveguide 25d. This is the same as FIG. 2 and FIG.

Next, the operation will be described.
In the waveguide directional coupler according to the first embodiment, as shown in FIGS. 1 to 3, the deformed waveguides 24a, 24b, 24c, and 24d whose yz cross-sectional shapes are notched. It has.
Further, the first region (the shaded region in FIG. 3) in the transformation waveguides 24a to 24d connected to the connection waveguides 23a to 23d and the input / output waveguides 25a to 25d are connected. The second regions (the shaded regions in FIG. 3) in the transformed waveguides 24a to 24d are orthogonal to each other.
The shape of the power input / output ends of the connection waveguides 23a to 23d is such that the length in the y direction is longer than the length in the z direction, and the power input / output ends of the input / output waveguides 25a to 25d. Is a shape in which the length in the y direction is shorter than the length in the z direction.
Therefore, the connection waveguides 23a to 23d, the transformation waveguides 24a to 24d, and the input / output waveguides 25a to 25d form a twist structure that rotates the direction of power by 90 degrees.

Here, FIG. 4 is a perspective view showing the short slot coupler. In FIG. 4, the same reference numerals as those in FIG.
The transformation waveguide 27a is connected between the connection waveguide 23a and the input / output waveguide 28a, and the length of the transformation waveguide 27a in the y direction is greater than the length of the connection waveguide 23a in the y direction. Is longer than the length of the input / output waveguide 28a in the y direction.
The transformation waveguide 27b is connected between the connection waveguide 23b and the input / output waveguide 28b, and the length of the transformation waveguide 27b in the y direction is greater than the length of the connection waveguide 23b in the y direction. Is longer than the length of the input / output waveguide 28b in the y direction.
The transformation waveguide 27c is connected between the connection waveguide 23c and the input / output waveguide 28c, and the length of the transformation waveguide 27c in the y direction is greater than the length of the connection waveguide 23c in the y direction. Is longer than the length of the input / output waveguide 28c in the y direction.
The transformation waveguide 27d is connected between the connection waveguide 23d and the input / output waveguide 25d, and the length of the transformation waveguide 27d in the y direction is greater than the length of the connection waveguide 23d in the y direction. Is longer than the length of the input / output waveguide 28d in the y direction.

One end of the input / output waveguide 28a is connected to the modified waveguide 27a.
One end of the input / output waveguide 28b is connected to the modified waveguide 27b.
One end of the input / output waveguide 28c is connected to the modified waveguide 27c.
One end of the input / output waveguide 28d is connected to the modified waveguide 27d.
The wide wall surfaces 29 of the input / output waveguides 28a to 28d face the + z direction in the figure.

The short slot coupler of FIG. 4 is a waveguide directional coupler having four input / output waveguides 28a to 28d. For example, power input from the input / output waveguide 28a is input to the input / output waveguide. 28c and the input / output waveguide 28d.
The short slot coupler of FIG. 4 has the lengths in the x, y and z directions of the transformation waveguides 27a to 27d connected between the connection waveguides 23a to 23d and the input / output waveguides 28a to 28d. By setting the length appropriately, it is possible to obtain a reflection characteristic close to the reflection characteristic of the waveguide directional coupler of FIG.

However, in order for the short slot coupler of FIG. 4 to obtain a reflection characteristic close to the reflection characteristic of the waveguide directional coupler of FIG. 1 in the first embodiment, the length of the transformation waveguides 27a to 27d in the x direction is long. It is necessary to make the length longer than the length of the metamorphic waveguides 24a to 24d in the x direction. Therefore, the size of the short slot coupler of FIG. 4 is larger than that of the waveguide directional coupler of FIG.
In the short slot coupler of FIG. 4, the wide wall surfaces 29 of the input / output waveguides 28a to 28d are directed in the + z direction in the figure. Therefore, the wide wall surface 29 of the input / output waveguide 28a and the wide wall surface 29 of the input / output waveguide 28b can face each other as in the waveguide directional coupler of FIG. Can not. Further, the wide wall surface 29 of the input / output waveguide 28c cannot face the wide wall surface 29 of the input / output waveguide 28d.

FIG. 5 is a perspective view showing a branch line coupler disclosed in Non-Patent Document 1. As shown in FIG.
The branch line coupler of FIG. 5 is a waveguide directional coupler having four input / output waveguides 31a to 31d.
The branch line coupler of FIG. 5 is similar to the waveguide directional coupler of FIG. 1 according to the first embodiment in that the wide wall surface 32 of the input / output waveguide 31a and the wide wall surface 32 of the input / output waveguide 31b Can face each other. Further, the wide wall surface 32 of the input / output waveguide 31c and the wide wall surface 32 of the input / output waveguide 31d can face each other.
However, when the branch line coupler of FIG. 5 is manufactured by cutting a metal block, the branch line coupler has a fine portion such as the branch 33, and therefore, when a drill having a large drill diameter is used, cutting is performed with high accuracy. I can't. For this reason, it is difficult for the branch line coupler of FIG. 5 to obtain a reflection characteristic close to that of the waveguide directional coupler of FIG.
When a branch line coupler is cut using a drill having a small drill diameter, the length that can be dug by the drill is short, so that it may not be dug to a desired position. In addition, since the amount that can be dug at a time is small, it may take a long time to complete the cutting process.

6 and 7 are explanatory views showing a method of manufacturing the waveguide directional coupler according to Embodiment 1 of the present invention.
In particular, FIG. 6 shows the xy plane of the waveguide directional coupler of FIG. 1, and FIG. 7 shows the xz plane of the waveguide directional coupler of FIG.
The waveguide directional coupler of FIG. 1 is formed by combining a plurality of metal blocks that have been cut in advance.

As shown in FIG. 6, the xy plane in the waveguide directional coupler of FIG. 1 is combined with metal blocks BL1, BL2, and BL3 divided into three. In FIG. 6, F indicates a surface that combines the metal block BL1 that has been cut in the + y direction and the metal block BL2 that has been cut in the −x direction and the + x direction.
G indicates a surface where the metal block BL2 is combined with the metal block BL3 that has been cut in the -y direction.
As shown in FIG. 7, the xz plane in the waveguide directional coupler of FIG. 1 is combined with metal blocks BL4 and BL5 which are divided into two. In FIG. 7, H indicates a surface where the metal block BL4 that has been cut in the + z direction and the metal block BL5 that has been cut in the −z direction are combined.

In the cutting of the metal block BL1 shown in FIG. 6, the surface on the + y direction side of the waveguide directional coupler is formed by cutting from the −y direction toward the + y direction.
The metal block BL2 shown in FIG. 6 is cut from the −y direction to the + y direction and from the + y direction to the −y direction.
Further, in the cutting of the metal block BL3 shown in FIG. 6, the surface on the −y direction side of the waveguide directional coupler is formed by cutting from the + y direction toward the −y direction.

In the cutting process of the metal block BL4 shown in FIG. 7, the surface on the + z direction side of the waveguide directional coupler is formed by cutting from the −z direction toward the + z direction.
The metal block BL5 shown in FIG. 7 is cut from the + z direction toward the -z direction to form a surface on the -z direction side of the waveguide directional coupler.

The cutting of the metal blocks BL1 to BL5 is a simple cutting that only forms a surface, and there is no cutting of fine parts such as the branch 33 as in the branch line coupler of FIG. Even with a drill, cutting can be performed with high accuracy.
In cutting using a drill, the corners of the metal blocks BL1 to BL5 do not become completely right angles, but have corners R corresponding to the diameter of the drill. However, since the design considering the corners R is easy, The influence of the corner R on the reflection characteristic of the waveguide directional coupler can be eliminated.

As apparent from the above, according to the first embodiment, the shape of the cross section perpendicular to the tube axis direction in the transformation waveguides 24a to 24d is cut off at two corners on one diagonal line in the quadrangle. It is a notch shape. In the cutout shape, the first region whose length in the tube width direction is longer than the length in the tube height direction is connected to the connection waveguides 23a to 23d or the input / output waveguides 25a to 25d. In the notch shape, the second region whose length in the tube width direction is shorter than the length in the tube height direction is connected to the input / output waveguides 25a to 25d or the connection waveguides 23a to 23d. ing. Thereby, even if the drill diameter of the drill used for a process is enlarged, there exists an effect which can obtain the reflective characteristic equivalent to the case where a drill with a small drill diameter is used. In addition, the tube axis direction is reduced in size.

In the first embodiment, the waveguide directional coupler includes the four transformation waveguides 24a to 24d. However, as shown in FIG. In place of the transformation waveguides 24c and 24d, transformation waveguides 27c and 27d as shown in FIG. 4 are provided. Instead of the input / output waveguides 25c and 25d, the input / output waveguides as shown in FIG. 28c and 28d may be provided.
FIG. 8 is a perspective view showing another waveguide directional coupler according to Embodiment 1 of the present invention.
9 and 10 are explanatory views showing another method of manufacturing a waveguide directional coupler according to Embodiment 1 of the present invention.
The manufacturing method of the waveguide directional coupler of FIG. 8 is the same as the manufacturing method of the waveguide directional coupler of FIG.

Embodiment 2. FIG.
In the first embodiment, as shown in FIG. 3, the dimension A which is the length in the y direction in the connection waveguides 23a to 23d and the length A in the z direction in the input / output waveguides 25a to 25d. An example in which the dimensions are the same, and the B dimension which is the length in the z direction in the connection waveguides 23a to 23d is the same as the B dimension which is the length in the y direction in the input / output waveguides 25a to 25d. Is shown.
In the second embodiment, the dimension A1 which is the length in the y direction in the connection waveguides 23a to 23d is different from the dimension A2 which is the length in the z direction in the input / output waveguides 25a to 25d. An example in which the B1 dimension which is the length in the z direction in the wave tubes 23a to 23d and the B2 dimension which is the length in the y direction in the input / output waveguides 25a to 25d will be described.

FIG. 11 is a transmission diagram showing a yz cross section of the connection waveguide 23c, the transformation waveguide 24c, and the input / output waveguide 25c.
In FIG. 11, the dotted line indicates the cross-sectional shape of the metamorphic waveguide 24c.
The solid line indicates the cross-sectional shape of the connection waveguide 23c, and the broken line indicates the cross-sectional shape of the input / output waveguide 25c.
As shown in FIG. 11, the metamorphic waveguide 24c has a cross-sectional shape perpendicular to the x direction, that is, a yz cross-sectional shape, in which two corners on one diagonal of a quadrangle are cut off. It has a notch shape.
Among the cutout shapes in the metamorphic waveguide 24c, the first region (the region shaded in FIG. 11) whose length in the y direction is longer than the length in the z direction is the connection waveguide 23c. It is the 1st pipe port connected.
In addition, in the cutout shape of the metamorphic waveguide 24c, the second region (the shaded region in FIG. 11) in which the length in the y direction is shorter than the length in the z direction is the input / output guide. This is a second tube port connected to the wave tube 25c.

In FIG. 11, the connection waveguide 23c, the transformation waveguide 24c, and the input / output waveguide 25c are illustrated. However, the connection waveguide 23a, the transformation waveguide 24a, and the input / output waveguide 25a are also illustrated. 11 is the same.
Further, the connection waveguide 23b, the transformation waveguide 24b, and the input / output waveguide 25b are the same as those in FIG. 11, and the connection waveguide 23d, the transformation waveguide 24d, and the input / output waveguide 25d are also illustrated. 11 is the same.

In FIG. 11, the dimension A1 which is the length in the y direction in the connection waveguide 23c is longer than the dimension A2 which is the length in the z direction in the input / output waveguide 25c (A1> A2). The B1 dimension which is the length of the z direction in 23c differs from the B2 dimension which is the length of the input / output waveguide 25c in the y direction (B1 ≠ B2). In FIG. 11, B1 and B2 appear to have almost the same length, but B1 ≠ B2. In addition, B1> B2 may be sufficient and B1 <B2 may be sufficient.
FIG. 11 shows an example in which the A1 dimension that is the length in the y direction in the connection waveguide 23c is longer than the A2 dimension that is the length in the z direction in the input / output waveguide 25c (A1> A2). However, the dimension A1 that is the length in the y direction in the connection waveguide 23c may be shorter than the dimension A2 that is the length in the z direction in the input / output waveguide 25c (A1 <A2).

According to the second embodiment, the same effects as those of the first embodiment can be obtained, the A dimension and the B dimension of the connection waveguides 23a to 23d, and the A dimension of the input / output waveguides 25a to 25d, Since it is not necessary to align with the B dimension, the A and B dimensions of the connecting waveguides 23a to 23d can be changed to the desired A and B dimensions of the input / output waveguides 25a to 25d. The degree of reflection can be increased to achieve better reflection characteristics.

Embodiment 3 FIG.
In the first embodiment, the example in which the two cutouts in the transformation waveguides 24a to 24d have the same size has been shown. However, in the third embodiment, the two cutouts in the transformation waveguides 24a to 24d are shown. An example in which the size of the notch is different will be described.

FIG. 12 is a transmission diagram showing a yz section in the connection waveguide 23c, the transformation waveguide 24c, and the input / output waveguide 25c.
In FIG. 12, the dotted line indicates the cross-sectional shape of the metamorphic waveguide 24c.
The solid line indicates the cross-sectional shape of the connection waveguide 23c, and the broken line indicates the cross-sectional shape of the input / output waveguide 25c.
As shown in FIG. 12, the metamorphic waveguide 24c has a cross-sectional shape perpendicular to the x direction, that is, a yz cross-sectional shape, in which two corners on one diagonal line in a quadrangle are cut off. It has a notch shape.
However, in the example of FIG. 12, since C1 <C2, the size of the cutout at the upper right in the drawing is larger than the size of the cutout at the lower left in the drawing.

Among the cutout shapes in the metamorphic waveguide 24c, the first region (the region shaded in FIG. 11) whose length in the y direction is longer than the length in the z direction is the connection waveguide 23c. It is the 1st pipe port connected.
In addition, in the cutout shape of the metamorphic waveguide 24c, the second region (the shaded region in FIG. 11) in which the length in the y direction is shorter than the length in the z direction is the input / output guide. This is a second tube port connected to the wave tube 25c.

In FIG. 12, the connection waveguide 23c, the transformation waveguide 24c, and the input / output waveguide 25c are illustrated. However, the connection waveguide 23a, the transformation waveguide 24a, and the input / output waveguide 25a are also illustrated. 12 is the same.
The connection waveguide 23b, the transformation waveguide 24b, and the input / output waveguide 25b are the same as those in FIG. 12, and the connection waveguide 23d, the transformation waveguide 24d, and the input / output waveguide 25d are also illustrated. 12 is the same.
Here, in the modified waveguides 24a to 24d, notches are provided in the + y direction, the + z direction, the -y direction, and the -z direction, but the -y direction, the + z direction, and the + y direction are shown. In addition, a notch may be provided in the −z direction.

In FIG. 12, the dimension A1 which is the length in the y direction in the connection waveguide 23c is longer than the dimension A2 which is the length in the z direction in the input / output waveguide 25c (A1> A2). The B1 dimension which is the length of the z direction in 23c differs from the B2 dimension which is the length of the input / output waveguide 25c in the y direction (B1 ≠ B2). In FIG. 12, B1 and B2 appear to have almost the same length, but B1 ≠ B2. In addition, B1> B2 may be sufficient and B1 <B2 may be sufficient.
FIG. 12 shows an example in which the A1 dimension that is the length in the y direction in the connection waveguide 23c is longer than the A2 dimension that is the length in the z direction in the input / output waveguide 25c (A1> A2). However, the dimension A1 that is the length in the y direction in the connection waveguide 23c may be shorter than the dimension A2 that is the length in the z direction in the input / output waveguide 25c (A1 <A2).
In FIG. 12, the two notches have different sizes in the y direction, but may be different in the z direction.

In the following, the effect of the difference in the size of the two notches in the transformation waveguides 24a to 24d will be described.
FIG. 13 is an explanatory view showing a short slot coupler which is a waveguide directional coupler.
FIG. 13A is an explanatory view showing the dimensions of the waveguide A of the short slot coupler, and FIG. 13B shows the position where the electric field is the strongest at the input / output end (D1 cross section) and the position near the center (D2 cross section). It is explanatory drawing shown.
As shown in FIG. 13A, since the input / output end (cross section of D1) of the waveguide directional coupler is away from the central portion, the position where the electric field is strongest is shown in FIG. It becomes the center of the tube A dimension (A3).
On the other hand, at a position close to the central portion (cross section D2), as shown in FIG.

For this reason, the two notches in the transformation waveguides 24a to 24d are equal in size to the two notches in the transformation waveguides 24a to 24d mounted on the waveguide directional coupler of FIG. When the notch size is different, the flow of power can be made smoother and the reflection characteristics can be improved.

Here, FIG. 14 is an explanatory view showing the electromagnetic field calculation result of the axial ratio in the waveguide directional coupler. FIG. 15 is an explanatory diagram showing electromagnetic field calculation results of reflection characteristics in the waveguide directional coupler.
The horizontal axis of FIG.14 and FIG.15 is the normalized frequency which has normalized the frequency with the design center frequency.
14 and 15, the dotted line indicates the case where the waveguide directional coupler is the branch line coupler of FIG. 5, and the broken line indicates a conductor in which the modified waveguides 24a to 24d shown in FIG. 11 are mounted. 1 shows a wave tube directional coupler.
A solid line indicates a waveguide directional coupler in which the modified waveguides 24a to 24d shown in FIG. 12 are mounted.
Both waveguide directional couplers are manufactured by cutting a metal block with a drill having the same drill diameter.

As is clear from FIG. 14, the waveguide directional coupler in which the modified waveguides 24a to 24d shown in FIG. 11 or FIG. 12 are mounted has an axial ratio characteristic as compared with the branch line coupler of FIG. It can be seen that is improved.
As is clear from FIG. 15, the waveguide directional coupler on which the modified waveguides 24a to 24d shown in FIG. 11 or FIG. 12 are mounted has a reflection characteristic as compared with the branch line coupler of FIG. It can be seen that is improved.
It should be noted that the two cutouts have different sizes compared to the waveguide directional coupler in which the modified waveguides 24a to 24d shown in FIG. The axial directional coupler and the reflection characteristic are more improved in the waveguide directional coupler on which the modified waveguides 24a to 24d shown in FIG. 12 are mounted.

As apparent from the above, according to the third embodiment, since the two notches in the transformation waveguides 24a to 24d are configured to have different sizes, the same effect as in the first embodiment can be obtained. In addition, the effect of further improving the axial ratio characteristics and the reflection characteristics can be obtained.

Embodiment 4 FIG.
In the first embodiment, the central axis in the y direction of the connection waveguides 23a to 23d connected to the first tube ports in the transformation waveguides 24a to 24d and the second axis in the transformation waveguides 24a to 24d. A waveguide directional coupler in which the center axis in the y direction in the input / output waveguides 25a to 25d connected to the tube ports is described.
In the fourth embodiment, a waveguide directional coupler in which the center axis in the y direction of the connection waveguides 23a to 23d is shifted from the center axis in the y direction of the input / output waveguides 25a to 25d will be described. To do.

FIG. 16 is a transmission diagram showing a yz section in the connection waveguide 23c, the transformation waveguide 24c, and the input / output waveguide 25c.
In FIG. 16, the dotted line indicates the cross-sectional shape of the metamorphic waveguide 24c.
The solid line indicates the cross-sectional shape of the connection waveguide 23c, and the broken line indicates the cross-sectional shape of the input / output waveguide 25c.
As shown in FIG. 16, the metamorphic waveguide 24c has a cross-sectional shape perpendicular to the x direction, that is, a yz cross-sectional shape, in which two corners on one diagonal of a quadrangle are cut off. It has a notch shape.

In FIG. 16, the connection waveguide 23c, the transformation waveguide 24c, and the input / output waveguide 25c are illustrated. However, the connection waveguide 23a, the transformation waveguide 24a, and the input / output waveguide 25a are also illustrated. This is the same as 16.
Further, the connection waveguide 23b, the transformation waveguide 24b, and the input / output waveguide 25b are the same as in FIG. 16, and the connection waveguide 23d, the transformation waveguide 24d, and the input / output waveguide 25d are also illustrated. This is the same as 16.
Here, in the modified waveguides 24a to 24d, notches are provided in the + y direction, the + z direction, the -y direction, and the -z direction, but the -y direction, the + z direction, and the + y direction are shown. In addition, a notch may be provided in the −z direction.

In FIG. 16, the dimension A1 which is the length in the y direction in the connection waveguide 23c is longer than the dimension A2 which is the length in the z direction in the input / output waveguide 25c (A1> A2). The B1 dimension which is the length of the z direction in 23c differs from the B2 dimension which is the length of the input / output waveguide 25c in the y direction (B1 ≠ B2). In FIG. 16, B1 and B2 appear to have almost the same length, but B1 ≠ B2. In addition, B1> B2 may be sufficient and B1 <B2 may be sufficient.
FIG. 16 shows an example in which the A1 dimension that is the length in the y direction of the connection waveguide 23c is longer than the A2 dimension that is the length in the z direction of the input / output waveguide 25c (A1> A2). However, the dimension A1 that is the length in the y direction in the connection waveguide 23c may be shorter than the dimension A2 that is the length in the z direction in the input / output waveguide 25c (A1 <A2).

In the fourth embodiment, the sizes of the two notches in the transformation waveguides 24a to 24d are different, the central axis in the y direction of the connection waveguides 23a to 23d, and the input / output waveguides 25a to 25d. Is shifted from the central axis in the y direction.
That is, the center axis in the y direction in the input / output waveguides 25a to 25d is offset by E1 from the center axis in the y direction in the connection waveguides 23a to 23d.
In FIG. 16, ● represents the central axis in the y direction of the connecting waveguide 23c, and ○ represents the central axis in the y direction of the input / output waveguide 25c.

By shifting the central axis in the y direction in the connection waveguides 23a to 23d and the central axis in the y direction in the input / output waveguides 25a to 25d, for example, the connection position with the polarization splitting / combining circuit can be changed. Therefore, the degree of freedom in design can be increased.

In the present invention, within the scope of the invention, any combination of the embodiments, or any modification of any component in each embodiment, or omission of any component in each embodiment is possible. .

The present invention is suitable for a waveguide directional coupler that inputs and outputs power.
The present invention is also suitable for a method of manufacturing a waveguide directional coupler that inputs and outputs power.

21 Central waveguide, 22a Branch waveguide (first branch waveguide), 22b Branch waveguide (second branch waveguide), 23a Connection waveguide (first connection waveguide) , 23b connection waveguide (second connection waveguide), 23c connection waveguide (third connection waveguide), 23d connection waveguide (fourth connection waveguide), 24a metamorphic waveguide Tube (first metamorphic waveguide), 24b metamorphic waveguide (second metamorphic waveguide), 24c metamorphic waveguide (third metamorphic waveguide), 24d metamorphic waveguide (fourth Metamorphic waveguide), 25a, input / output waveguide (first input / output waveguide), 25b, input / output waveguide (second input / output waveguide), 25c, input / output waveguide (third (Input / output waveguide), 25d, input / output waveguide (fourth input / output waveguide), 26, wide wall surfaces of input / output waveguides 25a to 25d, 27a, 27b, 27c, 27 Metamorphic waveguide, 28a, 28b, 28c, 28d input / output waveguide, 29 wide walls of input / output waveguides 28a-28d, 31a-31d input / output waveguide, 32 input / output waveguides 31a-31d Wide wall, 33 brunch.

Claims (7)

A metamorphic waveguide having one end connected to the connection waveguide and the other end connected to the input / output waveguide;
In the metamorphic waveguide, the shape of the cross section perpendicular to the tube axis direction is a notch shape in which two corners on one diagonal line in the quadrangle are notched,
In the notch shape, a first region whose length in the tube width direction is longer than the length in the tube height direction is connected to the connection waveguide or the input / output waveguide, A waveguide directional coupler characterized in that a second region whose length in the tube width direction is shorter than the length in the tube height direction is connected to the input / output waveguide or the connection waveguide. . A first waveguide connected to one end of the central waveguide and the central waveguide, and second and third ports on the opposite side of the first tubular port in the axial direction of the tube; One branching waveguide,
As the connection waveguide,
A first connecting waveguide whose one end is connected to a second port in the first branching waveguide;
A second connection waveguide having one end connected to a third port in the first branching waveguide;
As the metamorphic waveguide,
A first metamorphic waveguide having one end connected to the other end of the first connecting waveguide;
A second metamorphic waveguide having one end connected to the other end of the second connecting waveguide;
As the input / output waveguide,
A first input / output waveguide having one end connected to the other end of the first metamorphic waveguide;
The waveguide directional coupler according to claim 1, further comprising a second input / output waveguide connected at one end to the other end of the second metamorphic waveguide. A second branch guide having a first tube port connected to the other end of the central waveguide, and having second and third tube ports on the opposite side of the first tube port in the tube axis direction; With wave tubes,
As the connection waveguide,
A third connecting waveguide whose one end is connected to a second port in the second branching waveguide;
A fourth connection waveguide having one end connected to a third tube port in the second branch waveguide;
As the metamorphic waveguide,
A third metamorphic waveguide having one end connected to the other end of the third connecting waveguide;
A fourth metamorphic waveguide having one end connected to the other end of the fourth connecting waveguide;
As the input / output waveguide,
A third input / output waveguide having one end connected to the other end of the third metamorphic waveguide;
3. The waveguide directional coupler according to claim 2, further comprising: a fourth input / output waveguide connected at one end to the other end of the fourth metamorphic waveguide. The shape of the cross section perpendicular to the tube axis direction in the metamorphic waveguide is a cutout shape in which two corners on one diagonal line in the quadrangle are cut out, and a cut at one corner of the two corners. 2. The waveguide directional coupler according to claim 1, wherein the size of the notch is different from the size of the notch at the other corner of the two corners. A central axis in the tube width direction of the connection waveguide connected to one end of the metamorphic waveguide, and a central axis in the tube width direction of the input / output waveguide connected to the other end of the metamorphic waveguide The waveguide directional coupler according to claim 1, wherein the waveguide directional coupler is misaligned. A metamorphic waveguide having one end connected to the connection waveguide and the other end connected to the input / output waveguide;
In the metamorphic waveguide, the shape of the cross section perpendicular to the tube axis direction is a notch shape in which two corners on one diagonal line in the quadrangle are notched,
In the notch shape, a first region whose length in the tube width direction is longer than the length in the tube height direction is connected to the connection waveguide or the input / output waveguide, A waveguide directional coupler characterized in that a second region whose length in the tube width direction is shorter than the length in the tube height direction is connected to the input / output waveguide or the connection waveguide. Is
It is formed by combining metal blocks that are divided into three in the tube width direction,
The method of manufacturing a waveguide directional coupler in which the metal block divided into three is cut before being combined. The waveguide directional coupler is formed by combining a metal block divided into three in the tube width direction and a metal block divided into two in the tube height direction,
The waveguide directional coupler according to claim 6, wherein the metal block divided into three and the metal block divided into two are cut before being combined. Production method.

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