JP2019125829A - Higher-order mode coupler - Google Patents

Abstract

To provide a higher-order mode coupler that is compact and can be manufactured at low cost.SOLUTION: A higher-order mode coupler according to an embodiment of the present invention includes a first waveguide, a second waveguide, and a substrate. The substrate has a first surface and a second surface opposite to the first surface, and the first surface has a first coupling portion coupled to the opening of the end portion of the first waveguide, and the second surface has a second coupling portion coupled to the opening of the end portion of the second waveguide, and the substrate includes a plurality of transmission lines coupled to a region between the first coupling portion and the second coupling portion.SELECTED DRAWING: Figure 1

Description

  Embodiments of the present invention relate to high order mode couplers.

  In recent years, in the field of wireless communication devices, miniaturization and cost reduction of devices have been further demanded. This tendency is the same as in the high-order mode coupler which separates or combines the signal of the fundamental mode and the signal of the high-order mode. The high-order mode coupler generally comprises a main waveguide and a secondary waveguide connected to the periphery. When making a high-order mode coupler, it is common to process the metal into a complicated three-dimensional shape, but it is costly to manufacture.

  In addition, since the width of the sub waveguide needs to be half or more of the wavelength of the signal, the size and weight of the portion of the high order mode coupler related to the sub waveguide tends to be large. Because of these limitations, it is also difficult to reduce the overall size of the high-order mode coupler.

Unexamined-Japanese-Patent No. 11-112201 gazette Japanese Patent Application Laid-Open No. 60-160702

  Embodiments of the present invention provide a high-order mode coupler that is compact and can be manufactured at low cost.

  A high-order mode coupler as an embodiment of the present invention comprises a first waveguide, a second waveguide, and a substrate. The substrate has a first surface and a second surface opposite to the first surface, and the first surface has a first coupling portion coupled to the opening of the end portion of the first waveguide. The second surface has a second coupling portion coupled to the opening of the end of the second waveguide, and the substrate is a region between the first coupling portion and the second coupling portion. And a plurality of transmission lines coupled to the

FIG. 2 is a view showing an example of the arrangement of a high-order mode coupler according to the first embodiment. The figure which shows the structural example of the high-order mode coupler isolate | separated into parts. The figure which shows the example of the cross-sectional shape of a waveguide. The figure which showed each layer of the circuit board of a high-order mode coupler. Sectional drawing of the circuit board which concerns on a high-order mode coupler. FIG. 2 is a cross-sectional view of a high order mode coupler according to the first embodiment. The figure which shows the example of the waveguide which becomes taper shape. The figure which shows the example of the waveguide which has become step shape. FIG. 8 is a view showing an example of the configuration of a circuit board of a high order mode coupler according to a second embodiment. FIG. 7 is a view showing a configuration example of a circuit board of a high order mode coupler according to a third embodiment. FIG. 7 is a view showing an example of the configuration of a circuit board of a high order mode coupler according to a fourth embodiment. FIG. 13 is a view showing an example of the configuration of a circuit board of a high order mode coupler according to a fifth embodiment. Sectional drawing of the circuit board provided with conductor via | veer. The figure which shows the structural example which provided the groove | channel in the edge part of the waveguide. The figure which shows the structural example which provided the groove | channel and the periodic structure in the edge part of the waveguide. FIG. 18 is a view showing a configuration example of a circuit board of a high order mode coupler according to an eighth embodiment. FIG. 18 is a view showing an example of the arrangement of a high order mode coupler according to the ninth embodiment; The figure which shows the structural example of the plate which concerns on 9th Embodiment. The figure which shows the example of the synthetic | combination circuit connected to a high-order mode coupler. The figure which shows the example of the synthetic | combination circuit connected to a high-order mode coupler.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Further, in the drawings, the same components are denoted by the same reference numerals, and the description will be appropriately omitted.

First Embodiment
FIG. 1 shows a configuration example of a high-order mode coupler according to the first embodiment. FIG. 2 is a perspective view showing the high-order mode coupler 100 separated into parts. The high-order mode coupler 100 of FIG. 1 includes waveguides 101 a and 101 b and a substrate (high-order mode transmission substrate) 103.

  The waveguides 101a and 101b are main waveguides, and correspond to a first waveguide and a second waveguide, respectively. The waveguides 101a and 101b are arranged such that their tube axes coincide with each other. That is, the tube axis 102 coincides with the tube axis of the waveguide 101a and the tube axis of the waveguide 101b. The high-order mode transmission substrate 103 is disposed between the end of the waveguide 101a and the end of the waveguide 101b.

  The waveguides 101a and 101b are made of, for example, a metal such as copper, aluminum, brass or stainless steel. In addition, conductive materials other than metals, such as carbon fiber reinforced plastics (CFRP) may be used. You may use what plated metal on the surface of resin.

  FIG. 3 (A), FIG. 3 (B), FIG. 3 (C) and FIG. 3 (D) show examples of the cross-sectional shape of the waveguide. The cross-sectional shape of the waveguides 101a and 101b of FIG. 1 is a circular cross-sectional shape 10 shown in FIG. 3 (A). The cross-sectional shape of the waveguide may be any other shape as long as it is rotationally symmetric. Cross-sectional shapes 11 to 13 in FIGS. 3B to 3D are other examples of shapes having rotational symmetry. Although the cross-sectional shape 11 in FIG. 3B is circular, a ridge is provided on the inner wall. The cross-sectional shape 12 of FIG. 3C is square. Although the cross-sectional shape 13 in FIG. 3D is square, a ridge is provided on the inner wall.

  The waveguide in the case where the cross-sectional shape is the cross-sectional shape 11 in FIG. 3 (B) or the cross-sectional shape 13 in FIG. 3 (D) is a ridge waveguide. The ridge may be formed of the same material as the body of the waveguide or may be formed of a different material. Alternatively, a corrugated waveguide having a groove on the inner wall of the waveguide may be used.

  The waveguides 101a and 101b have the same cross-sectional shape and are formed of the same material. However, the waveguides 101a and 101b may have different cross-sectional shapes, or may be formed of different materials.

  The tube axes 102 of the waveguides 101a and 101b form the same straight line. In addition, the cross-sectional shapes of the waveguide 101 a which is the first waveguide and the waveguide 101 b which is the second waveguide are rotationally symmetric with respect to the tube axis 102. The arrangement and structure of the waveguide can suppress reflection and generation of unnecessary modes.

  FIG. 4 is a perspective view showing the layers of the high-order mode transmission substrate 103 in isolation. FIG. 5 is a cross-sectional view of the high-order mode transmission substrate 103 cut along the xy plane passing through the line AA ′ of FIG. The high-order mode transmission substrate 103 will be described below with reference to FIGS. 2, 4 and 5.

  The high-order mode transmission substrate 103 is a flat structure. Both surfaces of the high-order mode transmission substrate 103 face the ends of the waveguides 101a and 101b, respectively. Further, at the center of the high-order mode transmission substrate 103, the tube axes 102 of the waveguides 101a and 101b pass. The shape of the high-order mode transmission substrate 103 may be square, circular, or another shape.

  As shown in FIG. 4, the high-order mode transmission substrate 103 includes a conductor layer 105a corresponding to the first surface of the substrate 103, a conductor layer 105b corresponding to the second surface facing the first surface, and a conductor layer 105a. , 105b has a laminated structure with a dielectric layer (dielectric substrate) 107 which is an intermediate layer. The conductor layers 105a and 105b are made of, for example, a conductor such as copper, aluminum, brass, stainless steel or the like. The dielectric substrate 107 is a dielectric substrate formed of a dielectric such as epoxy resin, fluorine resin (PTFE), polyphenylene ether resin (PPE), liquid crystal polymer, polyimide, ceramic, mica or the like. The dielectric substrate 107 may be formed of a single layer or may include a plurality of layers. When the dielectric layer includes a plurality of layers, each layer may be formed of the same material or may be formed of different materials. Glass cloth, ceramic filler and the like may be contained inside the dielectric layer.

  The conductor layer 105a is formed with an opening 106a which is a first coupling portion. The opening (first coupling portion) 106a is coupled to the opening at the end of the waveguide 101a. Further, the conductor layer 105b is formed with an opening 106b which is a second coupling portion. The opening (second coupling portion) 106 b is coupled to the opening at the end of the waveguide 101 b. The openings 106 a, 106 b are circular and the center coincides with the tube axis 102. The circles of the openings 106a, 106b are equal in diameter and area to one another. Therefore, when viewed in the direction perpendicular to the xy plane, the positions of the openings 106a and 106b overlap.

  However, the shapes of the openings 106 a and 106 b may be rotational symmetric, and the shapes of the opening 106 a and the opening 106 b may be different. The openings 106a and 106b are rotationally symmetric, and the centers of the openings 106a and 106b coincide with the tube axis 102, thereby suppressing the occurrence of reflection and unnecessary modes.

  The dielectric substrate 107 is provided with a plurality of (here four) transmission lines 104. The end (one end) of the transmission line 104 is coupled to the region of the dielectric substrate 107 between the opening 106 a and the opening 106 b. Each transmission line 104 is formed to extend outward from the region. The transmission line 104 corresponds to a sub waveguide. Examples of the transmission line according to the present embodiment include a strip line, a microstrip line, a coaxial line, a post-wall waveguide (SIW: Substrate-Integrated Waveguide) and the like, but the structure is not particularly limited. The transmission line 104 may be hollow formed in the dielectric substrate 107.

  The directions of the four transmission lines 104 are shifted by 90 degrees. The number of transmission lines may not be four. For example, two, three or more transmission lines may be provided. Further, although all the transmission lines 104 are linear, it is possible to use a curved transmission line.

  FIG. 6 is a cross-sectional view of the high-order mode coupler 100 cut along the z-x plane passing through the tube axis 102.

  The end of the waveguide 101 a is in contact with the conductor layer 105 a on the surface of the substrate 103. In order to reduce leakage of electromagnetic waves, it is preferable that there is no gap between the high-order mode transmission substrate 103 and the waveguide 101a. In addition, a force in the negative z-axis direction may be applied to the waveguide 101a to make it difficult to shift the position.

  The end of the waveguide 101 b is in contact with the conductor layer 105 b on the surface of the high-order mode transmission substrate 103. In order to reduce leakage of electromagnetic waves, it is preferable that there is no gap between the high-order mode transmission substrate 103 and the waveguide 101b. In addition, a force in the z-axis positive direction may be applied to the waveguide 101b to make it difficult to shift the position.

(Function of higher order mode coupler)
Each of the transmission lines 104 is connected to, for example, a synthesis circuit for electromagnetic waves such as microwaves or millimeter waves (see FIGS. 19 and 20 described later). In the synthesis circuit, synthesis or distribution of electromagnetic wave signals such as microwaves and millimeter waves is performed. Also, a horn antenna at the end of the waveguide 101a (the end opposite to the high-order mode transmission substrate 103) or the end of the waveguide 101b (the end opposite to the high-order mode transmission substrate 103) described above And the like are formed. The horn antenna can be formed, as an example, by gradually widening the open area of the open end at the end of the waveguide. In this case, the waveguide 101a or the waveguide 101b functions as a waveguide and an antenna. In the following description, it is assumed that an antenna is formed at the end of the waveguide 101a, and an operation at the time of reception and an operation at the time of transmission will be described.

  An electromagnetic wave (high frequency signal) received by the antenna at the time of reception propagates inside the waveguide 101a. A component relating to a higher order mode of a part of the electromagnetic wave entering from the waveguide 101 a is extracted from the transmission line 104 in the dielectric substrate 107. Similarly, part of the fundamental mode component of the electromagnetic wave entering from the waveguide 101 a is also taken out from the transmission line 104 in the dielectric substrate 107.

  The propagation mode of the electromagnetic wave traveling through the waveguide depends on the cross-sectional shape of the waveguide. For example, if a circular waveguide that is circular in cross-sectional shape is used, the fundamental mode is the TE11 mode. At this time, a plurality of higher order modes exist. Examples of typical higher order modes include TM01 mode, TE21 mode, TE21 * mode, TE01 mode, and the like. The TE21 * mode is a propagation mode obtained by rotating the electromagnetic field distribution of the TE21 mode by 45 degrees.

  In the case of a rectangular waveguide having a rectangular cross-sectional shape, the fundamental mode is the TE10 mode (or TE01 mode). Typical high-order modes include TE01 mode (or TE10 mode), TM11 mode, TE20 mode, TE02 mode, TE11 mode, and the like. When the cross-sectional shape is a square, the basic mode is a mode in which the TE10 mode and the TE01 mode are degenerated.

  The transmission line 104 may be configured to enable distribution or combination of a plurality of different higher order modes. For example, it is possible to use a configuration in which four transmission lines, each of which is shifted by 45 degrees, are added to the four transmission lines according to the present embodiment. In this case, the TE21 mode of the circular waveguide and the TE21 * mode can be taken out separately.

  In the case of transmission, the operation is the reverse of reception. For example, an electromagnetic wave of the fundamental mode enters from the waveguide 101b. On the other hand, high-order mode electromagnetic waves are input from the combining circuit via the transmission lines 104. In the region where the transmission lines 104 in the high-order mode transmission substrate 103 are coupled, the electromagnetic wave of the fundamental mode and the electromagnetic wave of the high-order mode are mixed, and the mixed electromagnetic wave propagates through the waveguide 101a and is transmitted from the antenna.

(Modification 1)
The waveguides 101a and 101b may have shapes other than cylindrical as long as they are rotationally symmetric about the tube axis. FIG. 7 shows an example of a tapered waveguide. The waveguide in FIG. 7 has a larger diameter (inner diameter) as it proceeds in the z-axis plus direction. By changing the inner diameter of the waveguide in this manner, it is possible to adjust the propagation mode and cut-off frequency in the waveguide and to prevent the propagation of unwanted higher order modes.

  FIG. 8 shows an example of a stepped waveguide. In the example of FIG. 8, the diameter (inner diameter) of the waveguide changes in the middle, and a step is generated on the inner wall. Even with such a waveguide, it is possible to adjust the propagation mode and cut-off frequency in the waveguide and to prevent the propagation of unwanted higher order modes.

(Modification 2)
In the first embodiment, although the first surface of the high-order mode transmission substrate 103 is the conductor layer 105 a and the second surface is the conductor layer 105 b, the first surface and the second surface of the high-order mode transmission substrate 103 May be a dielectric layer (dielectric substrate). Although the leakage suppression effect of electromagnetic waves is reduced by this, an effect of weight reduction can be obtained. In this case, the layer between the first surface and the second surface may be physically integrated integrally for the dielectric layer (dielectric substrate) 107.

Second Embodiment
In the second embodiment, an opening penetrating in the z-axis direction is provided between the front surface and the back surface of the dielectric substrate in the high-order mode transmission substrate 103, that is, a hole (opening) penetrating the central portion of the dielectric substrate.

  FIG. 9 shows a configuration example of the high-order mode transmission substrate 103 of the high-order mode coupler according to the third embodiment. Similar to the high-order mode transmission substrate 103 according to the first embodiment, the high-order mode transmission substrate 103 in FIG. 9 has conductor layers 105 a and 105 b formed on both sides of a dielectric substrate. The conductor layers 105a and 105b are provided with openings 106a and 106b as in the first embodiment. Further, in the dielectric substrate 107, four transmission lines 104 are formed as in the first embodiment.

  In the center of the dielectric substrate 107, a hole (opening) 130 penetrating in the z-axis direction is provided. The holes 130 are in communication with the openings 106a, 106b. The hole 130 has a circularly symmetrical shape such as a circle, the center of which coincides with the tube axis 102 of the waveguide. The hole 130 allows an electromagnetic wave propagating in one of the waveguide 101a or the waveguide 101b to propagate to the other of the waveguide 101a or the waveguide 101b without passing through the substance of the dielectric layer 107. This can reduce the reflection and loss caused by the dielectric layer. In addition, since the center of the hole 130 is aligned with the tube axis 102 and the shape is rotationally symmetric, it is possible to suppress the reflection in the waveguide and the generation of the unnecessary mode.

Third Embodiment
In the high-order mode couplers according to the above-described embodiments, the high-order mode transmission substrate 103 is configured by forming conductor layers (metal layers) on both surfaces of the dielectric substrate. In the present embodiment, the entire high-order mode transmission substrate 103 is formed of a conductor such as metal. By forming the entire high-order mode transmission substrate 103 of a conductor, propagation loss can be reduced and efficient transmission can be performed.

  FIG. 10 shows a configuration example of the high-order mode transmission substrate of the high-order mode coupler according to the third embodiment. The high-order mode transmission substrate 103a of FIG. 10 includes a conductor layer 105c, a conductor layer 105e which is an intermediate layer, and a conductor layer 105d. In the first embodiment, the intermediate layer is a dielectric substrate, but in the present embodiment, it is formed of a conductor. Four transmission lines 104 are formed in the conductor layer 105 e. For example, the transmission line 104 can be formed by cutting a metal plate. Thereby, the whole of the conductor layer 105e and the conductor layer 105d can be integrally formed.

  In the example of FIG. 10, the cross-sectional shape of the transmission line 104 is rectangular. Such a transmission line is called a rectangular waveguide. The cross-sectional shape of the transmission line 104 may be a shape other than a rectangle, and may be another type of waveguide. For example, a ridge waveguide or a gap waveguide may be formed. The transmission line may be a straight path or may have a curved path.

  The high-order mode transmission substrate 103a has a hole (opening) penetrating in the z-axis direction at the center. Specifically, the conductor layer 105c has an opening 106a, the conductor layer 105d has an opening 106b, and the conductor layer 105e has an opening (hole) communicating with the openings 106a and 106b. The shape of these openings is rectangular or square. The waveguides 101a and 101b are coupled to the openings 106a and 106b such that the centers of the openings 106a and 106b coincide with the tube axis 102 of the waveguide.

  As described above, according to the present embodiment, transmission loss can be reduced by forming the entire high-order mode transmission substrate with metal. When the metal layers are formed on both surfaces of the dielectric substrate as in the first embodiment, there is an advantage that the weight of the high-order mode transmission substrate can be reduced and the weight of the entire high-order mode coupler can be suppressed.

Fourth Embodiment
In the present embodiment, by providing conductor vias in the high-order mode transmission substrate, unnecessary reflection of electromagnetic waves and electromagnetic wave leakage into the high-order mode transmission substrate are suppressed.

  FIG. 11 shows a configuration example of a high-order mode transmission substrate of the high-order mode coupler according to the fourth embodiment. Conductor layers 105 a and 105 b are formed on both surfaces of the dielectric substrate 107 as in the substrate according to the first embodiment. Openings 106a and 106b are formed in the conductor layers 105a and 105b. Further, four transmission lines 104 are formed on the dielectric substrate 108 as in the first embodiment.

  Conductor vias 109 are periodically provided along the outer periphery of the openings 106a and 106b. The conductor vias 109 are holes penetrating the high-order mode transmission substrate in the z-axis direction. The side walls in the holes of the conductor vias 109 are covered with a conductor such as metal. Therefore, the conductor layers 105 a and 105 b are electrically connected via the conductor layer on the side wall of the conductor via 109. By using such a structure, unnecessary reflection and leakage of electromagnetic waves into the high-order mode transmission substrate can be suppressed.

Fifth Embodiment
Various structures can be used as a transmission line corresponding to the sub waveguide. In the present embodiment, conductor vias are used to form a transmission line.

  FIG. 12 shows a configuration example of a high order mode transmission substrate of the high order mode coupler according to the fifth embodiment. Metal layers 105 a and 105 b are formed on both sides of the dielectric substrate 107. A plurality of pairs of conductor via rows 109a are provided from the outer periphery of the openings 106a and 106b outward. The conductor via 109a is a hole penetrating the high-order mode transmission substrate in the z-axis direction, and the side wall in the hole is covered with a conductor such as metal. The conductor layers 105 a and 105 b are electrically connected via the conductor layer on the side wall of the conductor via 109. Each pair of conductor via rows 109a is a row of conductor vias 109a parallel to each other. In this example, four pairs are formed at an interval of 90 degrees.

  FIG. 13 is a cross-sectional view of the high-order mode transmission substrate of FIG. 12 cut along the yz plane passing through the line BB ′. A portion sandwiched by each pair (a row of conductor vias parallel to one another) in the dielectric substrate 107 corresponds to the transmission line 104a. That is, the transmission line 104a in the present embodiment is a post wall waveguide (SIW).

Sixth Embodiment
In the present embodiment, the leakage of electromagnetic waves is suppressed by forming a choke structure at the end of the waveguide.

  FIG. 14 shows an example in which a choke structure is formed on the surface facing the substrate at the end of the waveguide 101a, that is, the surface coupled to the substrate (hereinafter referred to as the coupling surface). The upper part of FIG. 14 is a cross-sectional view of the waveguide 101a taken along the zx plane. The lower part of FIG. 14 is a front view of the coupling surface of the end of the waveguide 101a. A groove 110 is circumferentially formed on the coupling surface of the end of the waveguide 101a. Such a grooved structure is called a choke structure. Note that the wall of the inner part of the groove is shorter than the outer wall, but is not limited thereto.

  By providing the choke structure on the coupling surface of the end of the waveguide 101a as described above, it is possible to reduce the leakage of the electromagnetic wave from between the end of the waveguide 101a and the high-order mode transmission substrate. Although the choke structure is provided in the waveguide 101a in this example, it may be formed in the waveguide 101b, or may be formed in both of them.

Seventh Embodiment
In the sixth embodiment described above, the choke structure is provided on the coupling surface at the end of the waveguide, but a periodic structure may be provided instead of the choke structure.

  FIG. 15 shows an example in which a periodic structure is provided on the coupling surface of the end of the waveguide 101a. The upper part of FIG. 15 is a cross-sectional view of the waveguide 101 a cut along a zx plane passing through the tube axis 102. The lower part of FIG. 15 is a front view of the coupling surface of the end of the waveguide 101a.

  A circumferential groove 110 is formed on the coupling surface of the end portion of the waveguide 101 a, and a plurality of convex portions 111 are periodically provided in the groove 110. That is, the concavo-convex structure is formed inside the groove 110. The structure including the grooves 110 and the protrusions 111 shown in FIG. 15 is called an electromagnetic band gap (EBG) structure. The electromagnetic band gap structure is a periodic structure smaller than the wavelength of the electromagnetic wave, and has a frequency band for blocking the electromagnetic wave.

  In the example of FIG. 15, the periodic structure of the convex portions 111 is in one line, but the periodic structure may be, for example, a plurality of lines such as two lines or three lines.

  Although the electromagnetic band gap structure is formed in the waveguide 101a in the present embodiment, it may be formed in the waveguide 101b, or may be formed in both of them.

  As described above, according to the present embodiment, the electromagnetic band gap structure is provided on the coupling surface at the end of the waveguide, thereby reducing the leakage of the electromagnetic wave from between the end of the waveguide and the high-order mode transmission substrate. it can. Compared to the case where the choke structure of the sixth embodiment is provided, leakage of electromagnetic waves is suppressed in a wide frequency band.

Eighth Embodiment
In the seventh embodiment described above, the periodic structure is formed on the coupling surface at the end of the waveguide, but in the present embodiment, the periodic structure is formed on the high-order mode transmission substrate.

  FIG. 16 shows a configuration example of a high order mode transmission substrate of the high order mode coupler according to the eighth embodiment. The upper part of FIG. 16 is a cross-sectional view of the high-order mode transmission substrate 103 b cut along the z-x plane passing through the tube axis 102. The lower part of FIG. 16 is a front view of the high-order mode transmission substrate 103b in the negative z-axis direction. The high-order mode transmission substrate 103b is provided with a hole (opening) 160 penetrating in the z-axis direction. The center of the bore 160 coincides with the tube axis 102.

  The high-order mode transmission substrate 103b is formed of four layers: a dielectric layer 108, a conductor layer 105a, a dielectric substrate (dielectric layer) 107, and a conductor layer 105b. Four transmission lines 104 are formed on the dielectric substrate 107. At the bottom of FIG. 16, a top view of the dielectric layer 108 is shown.

  In the dielectric layer 108, a periodic structure 112 is formed along the periphery of the hole 160. The periodic structure 112 is formed of a metal structure embedded in the dielectric layer 108. The periodic structure 112 includes three circumferentially circumferential rows. In each row, metal structures are periodically arranged in the circumferential direction. The metal structure is, for example, screw-shaped. The coupling surface at the end of the waveguide 101a or 101b faces the portion where the periodic structure 112 is formed.

  The configuration of the periodic structure 112 may relate to other shapes or types. For example, conductor vias may be formed along the outer periphery of the hole 160. A convex structure (for example, metal) may be formed on the surface of the conductor layer 105 a or 105 b or both along the outer periphery of the hole 160. Also, a plurality of recesses may be regularly formed on the surface of the conductor layer 105 a or 105 b or both along the outer periphery of the hole 160. Although the example in which the periodic structure 112 is formed of metal is shown here, the periodic structure 112 may be formed by a method other than forming of the metal. For example, the periodic structure 112 may be a periodic hole formed in the dielectric layer 108.

  As described above, according to the present embodiment, the periodic structure 112 is provided in a portion coupled (opposed) to the coupling surface of the end portion of the waveguide, whereby the end portion of the waveguide and the high-order mode transmission substrate It is possible to suppress the leakage of electromagnetic waves from between.

Ninth Embodiment
In the present embodiment, a component having a periodic structure is added between the waveguide and the high-order mode transmission substrate.

  FIG. 17 is a cross-sectional view of the high-order mode coupler 150 according to the ninth embodiment taken along the z-x plane through the tube axis 102. In FIG. 17, the high-order mode coupler is disassembled into a plurality of parts. Although these figures are shown, in practice these parts are longitudinally coupled along the paper. The plate (first conductor substrate) 120 a is disposed between the waveguide 101 a and the conductor layer 105 a of the high-order mode transmission substrate 103. The plate (second conductor substrate) 120 b is disposed between the conductor layer 105 b of the high-order mode transmission substrate 103 and the waveguide 101 b.

  The plates 120a and 120b are formed of a conductive material such as metal. The material of the plates 120a, 120b may be the same as or different from the waveguides 101a, 101b.

  FIG. 18 shows a configuration example of the plate 120a. The structure of the plate 120b is similar to that of the plate 120a. The upper part of FIG. 18 is a cross-sectional view of the plate 120 a taken along the z-x plane passing through the tube axis 102. The lower part of FIG. 18 is a front view of the plate 120a from the z-axis direction. The plate 120 a has a hole (opening) 161 at the center. The holes 161 are circular. In the plate 120a, the center of the hole 161 coincides with the tube axis 102 of the waveguides 101a and 101b.

  Along the outer periphery of the hole 161, a groove 121a is provided on the surface of the plate 120a, and a groove 122a is provided on the back surface. That is, the groove 121a is provided on the surface on the z-axis plus side of the plate 120a. The groove 122a is provided on the surface on the z axis negative side of the plate 120a.

  The plates 120a and 120b may be a combination of a conductive material such as metal and a dielectric, or may be formed only of a dielectric. Instead of the groove, a periodic structure such as an electromagnetic band gap structure may be formed.

  As shown in FIG. 17, the plate 120 a is coupled to the coupling surface at the end of the waveguide 101 a at the outer peripheral portion of the hole 161. This coupling surface faces the groove 121a of the plate 120a. The groove 122a opposite to the groove 121a faces the conductor layer 105a. The plate 120b is coupled to the coupling surface of the end of the waveguide 101b at the outer peripheral portion of the hole. This coupling surface faces the groove 122b of the plate 120b. The groove 121 b of the plate 120 b faces the conductor layer 105 b of the high-order mode transmission substrate 103.

  As described above, according to the present embodiment, by adding the plate having the groove or the periodic structure between the waveguide and the high-order mode transmission substrate, the plate between the high-order mode transmission substrate and the waveguide can be obtained. Leakage of electromagnetic waves can be suppressed, and efficient transmission can be realized.

  For example, a magic T, a hybrid circuit, a T-branch circuit, a directional coupler or the like may be formed on the high-order mode transmission substrate according to each embodiment described above. The transmission lines according to the various circuits described above may be of the same type as the transmission lines of the high-order mode transmission substrate main body, or may be of different types. By forming other circuits on the high-order mode transmission substrate, the wireless communication system can be miniaturized.

  In addition, components may be added to each component as long as the conditions regarding the periodicity, arrangement, and symmetry described above are satisfied. For example, the first waveguide, the second waveguide, the high-order mode transmission substrate, a screw hole, a groove, a protrusion, etc. may be formed on the plate, or a fixture for fixation may be connected. .

Tenth Embodiment
In this embodiment, a synthesis circuit connected to the high order mode coupler according to any of the first to ninth embodiments will be described.

  FIG. 19 shows an example of a combining circuit coupled to a higher order mode coupler. The synthesis circuit 200 outputs the high-order mode signal v only when the TE21 mode of the circular waveguide is input to the high-order mode transmission substrate 103. The synthesis circuit 200 includes magic T201 to T203 and non-reflection terminations 211 to 213, and is connected to the high-order mode transmission substrate 103.

The high-order mode transmission substrate 103 is as described in the above embodiments. Waveguides 101a and 101b (not shown in FIG. 19) are coupled to the centers of both sides of the high-order mode transmission substrate. Four transmission lines are formed on the high-order mode transmission substrate. The electromagnetic waves according to the high-order mode are branched from one waveguide to the four transmission lines, and the branched electromagnetic waves are u ₁ , u ₂ , u ₃ and u ₄ respectively.

  The magic T201 to T203 have four ports in total: a sum (Σ) port, a difference (Δ) port, and two other input / output ports (0 ° and 180 °). When microwaves of the same amplitude and in phase are input to the 0 ° port and the 180 ° port, it is possible to obtain an electromagnetic wave synthesized from the sum port. At this time, no electromagnetic wave is output from the difference port. Further, when electromagnetic waves having the same amplitude and in opposite phase to each other are input to the 0 ° port and the 180 ° port, it is possible to obtain the electromagnetic wave synthesized from the difference port. At this time, no electromagnetic wave is output from the sum port.

  The non-reflection terminations 211 to 213 are devices for terminating input electromagnetic waves without reflecting them. Examples of non-reflective terminations include dielectric loaded waveguides and coaxial non-reflective terminations using chip resistors, although other types of devices may be used.

  Next, the operation of the synthesis circuit 200 will be described.

The electromagnetic waves u ₃ and u ₄ relating to the high-order mode output from the high-order mode transmission substrate 103 are input to the magic T 201. When the electromagnetic waves u ₃ and u ₄ have equal amplitudes and opposite phases to each other, a combined signal is output only from the difference port of the magic T 201. Also, electromagnetic waves u ₁ and u ₂ relating to the high-order mode output from the high-order mode transmission substrate 103 are input to the magic T 203. When the electromagnetic waves u ₁ and u ₂ have the same amplitude and the opposite phase, the combined signal is output only from the difference port from the magic T 203. Then, the synthetic signal of the electromagnetic waves u ₃ and u _{4 and} the synthetic signal of the electromagnetic waves u ₁ and u ₂ are input to the magic T-type 202. When the composite signal of the electromagnetic waves u ₃ and u _{4 and} the composite signal of the electromagnetic waves u ₁ and u ₂ have the same amplitude and the same phase, the high-order mode signal v is output from the sum port of the magic T 202. When the TE21 mode of the circular waveguide is input to the high-order mode transmission substrate 103, the electromagnetic waves u ₃ and u ₄ and u ₁ and u ₂ have equal amplitudes and opposite phases. Further, since the composite signal of the electromagnetic waves u ₃ and u _{4 and} the composite signal of the electromagnetic waves u ₁ and u ₂ have the same amplitude and in phase with each other, the high-order mode signal v is output. When other modes such as TE11 mode and TM01 mode of a circular waveguide are inputted to the high-order mode transmission substrate 103, the electromagnetic waves are absorbed by the non-reflection terminators 201 to 203 and the high-order mode signal v is not outputted.

FIG. 20 shows another example of the synthesis circuit connected to the higher order mode coupler. The synthesis circuit 200a includes magic T201 to T204 and non-reflection terminations 212 and 214. Waveguides 101a and 101b (not shown in FIG. 19) are coupled to the centers of both surfaces of the high-order mode transmission substrate 103. The function of each component of the synthesis circuit 200 a is the same as each component of the synthesis circuit 200. The synthesis circuit 200 a receives the high-order mode signal v ₁ when the TE 21 mode of the circular waveguide is input to the high-order mode transmission substrate 103 and the high-order mode signal v ₂ when the TM 01 mode of the circular waveguide is input. Output.

  Next, the operation of the synthesis circuit 200a will be described.

The electromagnetic waves u ₃ and u ₄ relating to the high-order mode output from the high-order mode transmission substrate 103 are input to the magic T 201. When the electromagnetic waves u ₃ and u ₄ have equal amplitudes and opposite phases to each other, a combined signal is output only from the difference port of the magic T 201. When the electromagnetic waves u ₃ and u ₄ have the same amplitude and the same phase, the combined signal is output only from the sum port of the magic T 201. Also, electromagnetic waves u ₁ and u ₂ relating to the high-order mode output from the high-order mode transmission substrate 103 are input to the magic T 203. When the electromagnetic waves u ₁ and u ₂ have equal amplitudes and opposite phases to each other, a combined signal is output only from the difference port of the magic T 203. When the electromagnetic waves u ₁ and u ₂ have the same amplitude and the same phase, the combined signal is output only from the sum port of the magic T 203. Magic T202 is a high-order mode signal when the composite signal of electromagnetic waves u ₃ and u ₄ output from the differential port of magic T 201 and the composite signal of electromagnetic waves u ₁ and u ₂ output from the differential port of magic T 203 are in phase v Output ₁ Magic T204 is a high-order mode signal when the composite signal of electromagnetic waves u ₃ and u ₄ output from the sum port of magic T 201 and the composite signal of electromagnetic waves u ₁ and u ₂ output from the sum port of magic T 203 are in phase Output v ₂

  The synthesis circuit described in the present embodiment is only one of the applications of the high-order mode coupler according to the embodiment of the present invention. The high-order mode coupler according to the embodiment of the present invention can be applied to other circuits and wireless communication devices.

  A second application example is the combination with the primary radiator of the reflector antenna. Connecting the high order mode coupler to the primary radiator of the reflector antenna can form the directivity of the fundamental mode and the high order mode. The directivity of the basic mode is the largest sum pattern in the front direction of the antenna, and the directivity of the higher mode is the difference pattern of nulls in the front direction of the antenna. By using such a combination, it is possible to perform arrival angle estimation and beam scanning by the monopulse method.

  The third application example is realization of multi-mode transmission. As described above, the high-order mode coupler according to the embodiment of the present invention can transmit electromagnetic waves relating to a plurality of propagation modes with low loss. By carrying separate bit sequences using each propagation mode, the channel capacity is expanded and large data transmission is realized.

  As a fourth application example, measurement of physical property constant can be mentioned. By using a waveguide or a high-order mode of a waveguide resonator, it is possible to measure physical property constants of a substance such as complex dielectric constant. By using the high-order mode coupler according to the embodiment of the present invention, downsizing and weight reduction of the measuring instrument can be realized.

  The present invention is not limited to the above embodiments as it is, and at the implementation stage, the constituent elements can be modified and embodied without departing from the scope of the invention. In addition, various inventions can be formed by appropriately combining the plurality of components disclosed in the above-described embodiments. Further, for example, a configuration in which some components are removed from all the components shown in each embodiment is also conceivable. Furthermore, the components described in different embodiments may be combined as appropriate.

10, 11, 12, 13 cross-sectional shape 100, 150 high-order mode coupler 101a, 101b waveguide 102 tube axis 103, 103a, 103b high-order mode transmission substrate 104, 104a transmission line 105a, 105b, 105c, 105d conductor layer 106, 106a, 106b Opening 107 Dielectric Substrate 108 Dielectric Layer 109, 109a Conductor Via 110, 121a, 122a, 121b, 122b Groove 111 Convex Part 112 Periodic Structure 120a, 120b Plate 130, 160, 161 Hole 200, 200a Composite Circuit 201, 202, 203, 204 Magic T
211, 212, 213, 214 non-reflection termination

Claims (13)

A first waveguide,
A second waveguide,
And a substrate,
The substrate includes a first surface and a second surface opposite to the first surface,
The first surface has a first coupling portion coupled to the opening of the end of the first waveguide,
The second surface has a second coupling portion coupled to the opening of the end of the second waveguide,
The substrate includes a plurality of transmission lines coupled to a region between the first coupling portion and the second coupling portion. The first surface is constituted by a first conductor layer,
The second surface is constituted by a second conductor layer,
The first coupling portion is a first opening formed in the first conductor layer,
The high order mode coupler according to claim 1, wherein the second coupling portion is a second opening formed in the second conductor layer. The height of the said 1st opening and the said 2nd opening is formed in the area | region of the said board | substrate pinched | interposed into the said 1st opening and the said 2nd opening. Next mode coupler. The high-order mode coupler according to any one of claims 1 to 3, wherein a layer between the first surface and the second surface of the substrate is a dielectric layer. The high-order mode coupler according to claim 3, wherein a layer between the first surface and the second surface of the substrate is a conductor layer. The high-order mode coupler according to any one of claims 1 to 4, wherein the plurality of transmission lines are axisymmetric with respect to a tube axis of the first waveguide or the second waveguide. The high-order conductor according to claim 2, wherein a plurality of conductor vias which penetrate the substrate and connect the first conductor layer and the second conductor layer are formed around the first opening and the second opening. Mode coupler. The high-order mode coupler according to claim 7, wherein the plurality of conductor vias are formed to sandwich the transmission line. A groove is formed in a surface of the end of the first waveguide facing the first surface, and / or
A groove is formed in a surface of the end of the second waveguide opposite to the second surface,
The high order mode coupler according to any one of claims 1 to 8. A periodic structure of a conductive material is formed on a surface of the end of the first waveguide opposite to the first surface, and / or
A periodic structure of a conductive material is formed on a surface of the end of the second waveguide opposite to the second surface,
The high order mode coupler according to any one of claims 1 to 8. A periodic structure is formed along the periphery of the first coupling portion on the first surface, and / or,
The high-order mode coupler according to any one of claims 1 to 10, wherein a periodic structure is formed along the periphery of the second coupling portion on the second surface. A first conductor substrate is disposed between the first conductor layer and the first waveguide, and the first conductor substrate has a fourth opening communicating with the first opening, An opening at the end of the first waveguide is coupled to the fourth opening, and a first groove is formed along a periphery of the fourth opening, and an end of the first waveguide is Face the first groove and / or
A second conductor substrate is disposed between the second conductor layer and the second waveguide, and the second conductor substrate has a fifth opening communicating with the second opening, An opening at the end of the second waveguide is coupled to the fifth opening, and a second groove is formed along the periphery of the fifth opening, the end of the second waveguide being Opposite the second groove,
The high order mode coupler according to claim 2. The substrate receives a signal input from the first waveguide or the second waveguide to the plurality of transmission lines, and a combining circuit configured to obtain a high-order mode signal by combining the received signals. The high order mode coupler according to any one of claims 1 to 12, comprising:

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