JPH03190402A - Circularly polarized wave/linearly polarized wave converter - Google Patents

Abstract

PURPOSE:To simplify the manufacture process by converting a circularly polarized wave into a linearly polarized wave by a 1st means and reflecting an electromagnetic wave on a termination plane of the waveguide by a 2nd means so as to obtain a high level signal in an exciting probe. CONSTITUTION:A phase circuit 10 provided with two orthogonal electromagnetic wave modes in guide wavelength different is provided and prolonged up to a termination plane 11 of the waveguide and a metallic plate 13 is mounted to the termination plane 11 of the waveguide. Moreover, an exciting probe 12 is provided in the middle of the phase circuit, which converts a circularly polarized wave into a linearly polarized wave and a metallic plate is set so as to reflect an electromagnetic wave on the termination plane 11 of the waveguide and the tip of the metallic plate 13 respectively thereby obtaining a high level signal in the exciting probe 12 and sending the signal to the exciting probe. Thus, the structure of the phase circuit is made similarly from the mounting position of the phase circuit at the opening of the waveguide to the termination part of the waveguide. Thus, the number of forming dies is reduced and the manufacture process is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a circular polarization/linear polarization converter, and in particular to a circular polarization converter for electromagnetic waves used to reduce interference between two satellite broadcasting systems. This invention relates to a circular polarization/linear polarization converter used on the reception side and the transmission side for polarization. Here, the circularly polarized wave/linearly polarized wave converter includes a linearly polarized wave to circularly polarized wave converter and a circularly polarized wave to linearly polarized wave converter.

Broadcasting satellites in Japan emit right-handed circularly polarized electromagnetic waves as broadcast signals, and in order to create right-handed circularly polarized waves, a circular polarization converter is used to convert the linearly polarized waves into circularly polarized waves at the power feeding section of the antenna of the equipment onboard the satellite. In addition, right-handed circularly polarized electromagnetic waves from a broadcasting satellite are received by a reflector of a receiving BS antenna on the ground as shown in Figure 1, and the electromagnetic waves reflected by the reflector are transferred to a reflector. The electromagnetic waves are incident on the aperture of the primary radiator installed at the focal point of the wave, and then the electromagnetic waves are incident on the structural part that converts the circularly polarized waves into linearly polarized waves. It is converted into a linearly polarized wave and inputted to a BS converter, where it is converted into an electrical signal and signal processing is performed.

In principle, the linear polarization/circular polarization converter used in satellite equipment and the circular polarization/linear polarization converter used in ground receiving equipment are based on the same principle. can.

[Conventional technology]

FIG. 2 shows a conceptual diagram of a circularly polarized wave/linear polarized wave converter used in conventional terrestrial receiving equipment, viewed from the side. The primary radiator is shaped like a horn in order to efficiently collect the electromagnetic waves reflected by the reflector of the BS antenna and guide them to the waveguide section. This is a circular waveguide section provided to attenuate higher-order modes other than the fundamental mode of electromagnetic waves necessary for reception so as not to disturb the radiation characteristics of the primary radiator. This is the part of the phase circuit structure that performs wave conversion, and the input circularly polarized electromagnetic wave is converted into linearly polarized wave in the part of the phase circuit structure that performs circular/linear polarization conversion. The wave is guided to part C. Part C is a circular waveguide part, which is provided to achieve impedance matching between the phase circuit structure part and the circular waveguide part. Part D is a linearly polarized wave. This section is provided to efficiently extract signals from the electromagnetic waves to the outside of the waveguide using a coupling means using an excitation probe made of metal balls. The signal is input to an amplifier and subjected to signal processing.In addition to the above-mentioned excitation probe, a method using a rectangular waveguide is also used as a coupling means.

Approximate dimensions of each part as an example of the use of the structure shown in Figure 2 (
The length) is shown below.

Primary radiator part: 15mm, Part A: 12 mm, Part 8: 40 mm.

Part 0: 20 mm, Part D: 35 mm.

In addition, circularly polarized waves are two orthogonal linearly polarized waves with equal amplitudes and a phase shift of 90 degrees, and if a phase circuit is installed to make the phases of both linearly polarized waves the same, it becomes a linearly polarized signal. However, examples of phase circuit structures conventionally used for converting circularly polarized waves/linearly polarized waves are shown in FIGS. 3 to 8. In the figure, (a) is a front view seen from the opening of the waveguide, and (f) is a side view of the phase circuit section of the waveguide.

Figure 3 shows a dielectric plate that is tilted at 45 degrees to the direction of the linearly polarized wave that is to be extracted as a signal by the coupling means and parallel to the vertical electric field component Y of one of the two linearly polarized waves that are perpendicular to each other. 2 is attached inside the waveguide 1. By attaching the dielectric plate 2 inside the waveguide 1 in this way, the phase of the linearly polarized wave of the electric field component parallel to the dielectric plate 2 can be delayed, and therefore the phase of the linearly polarized wave of the other horizontal direction of the linearly polarized wave can be delayed. If the longitudinal dimensions of the dielectric plate 2 are selected to such a length that the component Y lags the electric field component Become. In addition to this, the following are used as examples of phase circuit structures. Figures 4 (a) and (b) show a phase circuit structure in which multiple screws 3 are attached to the centers of opposing circular arcs on the inner surface of the waveguide 1, so that the tip of each screw 3 is at the center of the waveguide. 5(a) and 5(b) show two metal plates 4 attached to the waveguide 1 as a phase circuit structure. The metal plates 4 are attached to the centers of opposing circular arcs on the inner surface so that the short sides of each metal plate 4 face toward the center of the waveguide 1, and the metal plates 4 are further extended in the longitudinal direction of the waveguide 1. It is installed.

Further, in FIG. 6, a metal block 5 is attached to the inner surface of the waveguide 1, extending in the longitudinal direction of the waveguide so that one arc of the inner surface of the waveguide becomes a plane. Figure 6 (a
), the vertical electric field component of two orthogonal linearly polarized waves is expressed as Y
If the electric field component in the horizontal direction is X, then by attaching the metal block 5 so that one arc of the inner surface of the waveguide becomes a plane, the internal wavelength of the electric field component Y can be changed structurally to the electric field component X. Since the frequency does not change, the electric field component Y lags behind the phase velocity inside the tube.
If the length in the longitudinal direction of the metal block 5 is selected to such a length that component Y is delayed in phase by 90 degrees from the electric field component Become. In addition to this, the following are used as examples of similar phase circuit structures. 7(a) and 7(b) show a phase circuit structure in which two metal blocks 5 of FIG. 6 are used and attached to two opposing circular arc parts, and FIG. 8(a)
) and et al.) are deformed so that the cross section seen from the opening of the waveguide 7 is elliptical.

[Problem to be solved by the invention]

Therefore, in the conventional circularly polarized wave/linearly polarized wave converter, the length from the end of the D section including the primary radiator section is approximately 120 mm, and the circularly polarized wave/linearly polarized wave converter is The part is long<B
In addition, it is difficult to downsize the S antenna, and there is a part with a phase circuit structure in the middle of the waveguide. The input part and the end part of the D part have to be molded in separate molds and then welded to each other, which is a disadvantage in that it requires a complicated manufacturing process.

The present invention aims to reduce the size of the waveguide section by deleting the 0 section shown in FIG. 2, and also reduces the number of molds to be molded by making the D section the same phase circuit structure as the B section. The purpose is to simplify the manufacturing process.

[Means to solve the problem]

FIG. 9 is a conceptual diagram showing a circular polarization/linear polarization converter for explaining the present invention in detail.

A primary radiator shaped like a horn to efficiently collect the electromagnetic waves reflected by the reflector of the BS antenna and guide them to the waveguide section, and a receiver for broadcast waves generated at the interface where the electromagnetic waves enter the phase circuit plane. The circular waveguide A section is provided to attenuate higher-order modes other than the necessary fundamental mode of electromagnetic waves so as not to disturb the radiation characteristics of the primary radiator, and the inner wavelength of the waveguide is A first means in which a phase circuit 10 having two different orthogonal electromagnetic wave modes is provided and extended to the end face 11 of the waveguide, and a metal plate 13 is provided on a surface perpendicular to the electric field of the electromagnetic wave having the longer wavelength in the tube. An excitation probe 12 is provided between the second means attached to the terminal surface 11 of the waveguide and the phase circuit 10 of the first means, and the first means converts the circularly polarized wave to the linearly polarized wave. , the electromagnetic waves are reflected by the second means and the end surface 11 of the waveguide so that a high-level signal is obtained at the excitation probe 12, and the excitation probe 12 connects the electromagnetic waves inside the waveguide with the circuit outside the waveguide. It is designed to transmit signals.

[Effect]

FIG. 10 shows a coordinate diagram for detailed explanation of the present invention, and as an example of a phase circuit structure, a metal block 17 is attached so that one arc of the inner surface of the waveguide becomes a plane, and further,
A metal block 17 is also attached to a portion of the arc opposite to the arc, with the electromagnetic wave propagation direction being the Z axis, the horizontal direction of the cross section parallel to the opening of the waveguide being the X axis, and the vertical direction being the Y axis, 2 present in part B (phase circuit structure part) of the waveguide
If the vector component in the X-axis direction of the two modes of electromagnetic waves is E, and the vector component in the Y-axis direction is E, then the electromagnetic wave E that combines both components is E=E, +E.

−a , −E−exp (j (ωt−βXZ)l
+a, -E-exp (j (ωt, -β, z-π
/2)]--・----1~---(1) It can be expressed as follows.

Here, E = amplitude constant, ω-2πf, t = time β, = E
, wave number β, =E, wave number ax = unit vector of X coordinate, = unit vector of Y coordinate.Furthermore, if the tube wavelengths of EX and Ey are λ9, λ, the following equation is obtained.

βX−2π/λ8 −・−−−−−−−−−(2) β
,=2π/λa −1111−−−−・−−−(3
) Now, as shown in FIG. 10, the structure of the B part (phase circuit) of the waveguide is made using two metal blocks 17 that face each other so that the arc of the inner surface of the waveguide becomes a plane. It is attached to the parts of two circular arcs, β, 〉β8, so λ,
〉λ.

Assume that it is designed as follows.

Determining the distance Z=L from 2 (1) where a circularly polarized wave becomes a linearly polarized wave by propagating B, βXL−βyL−π/ 2 −1−・・・−・−
--- (4) Furthermore, from equation (4), L = πX0.5/(β, -βX) ------(5
) is given by

As a specific example, a circular waveguide with the structure of part B as shown in FIG. 10 is used, and the internal diameter of the circular waveguide is approximately 19 mm.
+++m, maximum thickness 1.7m as a phase circuit structure
If m metal blocks are attached to the top and bottom of a circular waveguide, the structural wavelength inside the tube will be as follows.

λ, 54.4mm λy-38.6mm Therefore (
From equations 2), (3), and (5), the length of the structure of part B is L', 33.4 mm Furthermore, in the present invention, part D shown in FIG. 10 is also the same phase circuit as part B. Because of this structure, there are two orthogonal electromagnetic wave modes with different propagation constants in the D portion as well.

For these two modes of electromagnetic waves, the electromagnetic waves are reflected at the end surface of the waveguide and the tip of the metal plate attached to the end surface of the waveguide, so that a high-level signal can be obtained at the excitation probe 12. Therefore, the distance from the probe to the end surface of the waveguide or the short-circuit surface at the tip of the metal plate attached to the end surface of the waveguide must be approximately λ/4.
The distance between G and D in the figure is G'i38.6/4#9.7m+n D';54.4/4#13.6n+m.

Therefore, according to the present invention, in FIG. 9, the primary radiator section: 15 mm and the A section: 12 mm have the same length as the conventional example, but the 8th section: 40n+m (conventional example) → 34 mm (invention) 0 Part: 20n+m (conventional example) → 0 (present invention) 0 part: 35
The length of each part can be changed from mm (conventional example) to 14 mm (invention), and the total length can be approximately 45 mm shorter than the conventional example, and the overall length including the primary radiator part and A part can be changed. can be approximately 75 mm.

〔Example〕

FIG. 9 is a diagram showing a circularly polarized wave to linearly polarized wave converter that explains the present invention in detail, and has two orthogonal electromagnetic wave modes with different guide wavelengths near the opening of the waveguide. A phase circuit 10 is provided and extended to the terminal surface 11 of the waveguide, a metal plate I3 is attached to the terminal surface 11 of the waveguide on a plane perpendicular to the electric field of the electromagnetic wave having the longer wavelength in the tube, and further,
An excitation probe 12 is provided in the middle of the phase circuit 10,
The phase circuit 10 converts linearly polarized waves into circularly polarized waves or from circularly polarized waves to linearly polarized waves, and the electromagnetic waves are reflected at the tip of the metal plate 13 and the end face 11 of the waveguide, respectively.
Place the metal plate 1 in a position where you can get a high level signal from 2.
3 and the end face 11 of the waveguide, and the excitation probe 1
2, signals can be transmitted between electromagnetic waves inside the waveguide and circuits outside the waveguide.

9 and 10, a metal pole inserted into the waveguide through an opening provided on the side of the waveguide is used as an excitation probe 12 as a coupling means, or as shown in FIG. As shown in the figure, a rectangular waveguide 15 is attached to the side surface of the waveguide 14, and a substantially rectangular opening 16 is provided in the side surface of the waveguide 14 located at the opening of the rectangular waveguide 15 to extract electromagnetic waves. You can do it like this.

The length B from the mounting position of the phase circuit near the primary radiator to the excitation probe 12 shown in FIG. 9 is the length at which the circularly polarized wave incident on the phase circuit is converted into linearly polarized wave, and The mounting position of the excitation probe 12 from the end face 11 of the waveguide is set at a distance of approximately 1/4 of the wavelength of the electromagnetic wave with the longer wavelength in the tube, and the mounting position between the excitation probe 12 and the tip of the metal plate 13 is Approximately 1/4 of the wavelength of the electromagnetic wave with the shorter internal wavelength
The distance is G.

The length of the metal plate 13 in the longitudinal direction is the same as the inner diameter of the waveguide, and the metal plate 13 is attached inside the waveguide.
It is desirable that the thickness be as thin as possible if mechanical strength is maintained.

The circularly polarized electromagnetic wave incident from the primary radiator is transmitted to the phase circuit 1.
0 and becomes linearly polarized at the position of the excitation probe 12. Electromagnetic waves with longer wavelengths in the tube are reflected at the end surface 11 of the waveguide, and electromagnetic waves with shorter wavelengths in the tube are reflected at the tip of the metal plate 13, so that the attachment position of the reflecting surface and the excitation probe 12 is different. By setting the distance to about 1/4 of the wavelength of the electromagnetic wave, the excitation probe 12 can be excited in an optimal state.

Further, the -order radiator part has the same horn-shaped shape as the conventional example, and the A part connected to the -order radiator also uses a circular waveguide shape as in the conventional example.

12 to 17 show structural parts of the phase circuit of the present invention. In the figure, (a) shows a cross-sectional view of the waveguide seen from the opening of the waveguide, (b) shows a side view of the waveguide, and in figure (b), 1! , -g indicate the fracture line, and the upper part of the f-ff line indicates the fracture surface of the waveguide.

In FIG. 12, the phase circuit consists of a dielectric plate 22, and the angle with the center line of the excitation probe 21 is approximately 45 degrees when viewed from a cross section parallel to the opening of the waveguide (hereinafter referred to as waveguide cross section). The dielectric plate 22 is attached in such a direction as to extend in the longitudinal direction of the waveguide.
A metal plate 23 is attached to the end surface of the waveguide 20. Since the dielectric plate 22 and the metal plate 23 overlap, the dielectric plate 22 may be extended to the end surface of the waveguide 20 and the metal plate 23 may be attached to the surface of the dielectric plate 22, or the dielectric plate 22 may be pasted on the surface of the dielectric plate 22. Board 22
A metallic coating may be applied to the surface.

Alternatively, the dielectric plate 2 is
2 may be shortened in the longitudinal direction and attached side by side to the metal plate 23 attached to the end surface of the waveguide 20.

In FIG. 13, the phase circuit consists of a plurality of metal screws 24, each screw 24 is attached to the center of an opposite circular arc on the inner surface of the waveguide 20, and the tip of the screw is directed toward the center of the waveguide 20. Attach the screws 24 so that the angle between the center line connecting the opposing screws 24 and the center line of the excitation probe 21 is about 45 degrees when viewed from the cross section of the waveguide 20, and then Screws 24 are attached at equal intervals extending in the direction, and a metal plate 23 is attached to the end surface of the waveguide 20.

In FIG. 14, the phase circuit consists of two metal plates 25, each metal plate 25 is attached to the center of an opposite circular arc on the inner surface of the waveguide 20, and the short side of the metal plate 25 is connected to the waveguide. 2
0, and the metal plate 25 is attached so that the angle between the center line connecting the opposing metal plates 25 and the center line of the excitation probe 21 is about 45 degrees when viewed from the cross section of the waveguide 20. A metal plate 23 is attached to the end surface of the waveguide 20, extending in the longitudinal direction of the waveguide. Although the metal plate 25 and the metal plate 23 overlap at the corner of the end face of the waveguide 20, only one of the metal plates may be extended and attached at the overlapping portion.

In FIG. 15, the phase circuit consists of a metal block 26 and a waveguide 20.
The metal block 26 is arranged so that one arc of the inner surface of the metal block 26 is flat.
, and the metal block 26 is attached so that the angle between the extension line of the plane and the center line of the excitation probe 21 is approximately 45 degrees when viewed from the cross section of the waveguide 20, and the metal block 26 is extended in the longitudinal direction of the waveguide. A metal plate 23 is attached to the end surface of the waveguide 20. The corner of the end surface of the waveguide 20 is such that the metal lump 26 abuts against the end surface of the waveguide 20.

In FIG. 16, the metal lump shown in FIG. 15 is also attached to opposing circular arc portions on the inner surface of the waveguide, and the other parts have the same structure as the example shown in FIG. 16.

In FIG. 17, the phase circuit consists of a section of the waveguide 27 that has been deformed into an elliptical shape, and the angle between the center line connecting the centers of large arcs facing each other in the ellipse and the center line of the excitation probe 21 is used to guide the waveguide. The cross section of the waveguide 27 is deformed at an angle of approximately 45 degrees when viewed from the cross section of the tube 27, and a metal plate 2 is attached to the end surface of the waveguide 27.
3 is installed. In the case of this embodiment, A shown in FIG.
The part is a circular waveguide part, and it is necessary to connect an elliptical waveguide to the circular waveguide, but the connection part can be connected as is with a step, or it can be connected from a circular waveguide to a circular waveguide. The connection may be made by gradually deforming the shape into an oval shape.

The above is an example in which a circularly polarized wave/linearly polarized wave converter is used on the receiving side, but the structure according to the present invention is used as a circularly polarized wave generator, and the excitation is performed as shown in Fig. 9. By transmitting a signal from an external circuit using the probe 21 and exciting an electromagnetic wave inside the waveguide, a linearly polarized wave is generated at the position of the excitation probe 21, and the linearly polarized wave is generated by the length of the B section with a phase circuit structure. can be converted into a circularly polarized wave, and can also be radiated as a circularly polarized wave from a -order radiator.

In addition, in (a) of FIGS. 12 to 17, the mounting position of the excitation probe 21 is moved clockwise, and the mounting position of the excitation probe 21 before the movement and the center point of the waveguide are compared with each other after the movement. If the moving angle formed by the mounting position of the excitation probe 21 is 90 degrees, a counter-rotating circularly polarized wave/linearly polarized wave converter can be obtained.

〔Effect of the invention〕

As explained above, according to the present invention, the number of molds to be molded can be reduced by making the common ratio of the phase circuit from the installation position of the phase circuit at the opening of the waveguide to the terminal end of the waveguide the same. Therefore, it is possible to simplify the manufacturing process.In addition, a coupling means is provided in the middle of the phase circuit structure, and the end face of the waveguide is perpendicular to the electric field of the electromagnetic wave with the longer wavelength inside the waveguide. A metal plate is attached to the surface, and electromagnetic waves with a longer wavelength in the tube are reflected at the end surface of the waveguide, and electromagnetic waves with a shorter wavelength in the tube are reflected by the metal plate. By adjusting the distance between the metal plate and the coupling means, impedance matching can be achieved with respect to the coupling means, and the waveguide section can be made smaller, making it more economical and more compact. A circular/linear polarization converter can be provided.

[Brief explanation of drawings]

Fig. 1 is a schematic side view of a receiving BS antenna, Fig. 2 is a conceptual diagram of a conventional circularly polarized wave/linear polarized wave converter, and Fig. 3 (
a), (b) to Fig. 8 (a), (b) are phase circuit structure diagrams showing conventional examples, Fig. 9 is a conceptual diagram of a circularly polarized wave/linear polarized wave converter showing the principle of the present invention, FIG. 10 is a coordinate diagram for detailed explanation of the present invention, FIG. 11 is a schematic diagram showing a coupling means using a rectangular waveguide, and FIG. 12(a). 17(b) to 17(a) and 17(b) are structural diagrams of a phase circuit portion showing an embodiment of the present invention. 1.14.20 - A waveguide, 2. 22- dielectric plate, 3. 24- screw, 4,13,23.25 metal plate, 5,17.26- metal block, 7.27- elliptical waveguide, 10 - phase circuit, 11 end face of waveguide, 12-
Coupling means, 15-- rectangular waveguide, 16- opening;
21- Excitation probe.

Claims (11)

[Claims] (1) A waveguide with a horn-shaped primary radiator, a circular waveguide that attenuates higher-order modes unnecessary for transmission and reception, and a phase circuit inside the tube that has two orthogonal electromagnetic wave modes with different wavelengths. A tube and a termination surface provided at the end of the waveguide are sequentially connected, and a coupling means is provided in the middle of the phase circuit, and a linearly polarized wave signal is coupled to the coupling means to convert the linearly polarized wave to the circularly polarized wave. A circularly polarized wave/linearly polarized wave converter characterized by converting waves or circularly polarized waves to linearly polarized waves. (2) A metal plate is provided on the termination surface on a surface perpendicular to the electric field of the electromagnetic wave with the longer wavelength in the tube, and the electromagnetic wave with the longer wavelength in the tube is reflected by the termination surface, and the electromagnetic wave with the shorter wavelength in the tube is reflected. Claim (1) characterized in that impedance matching with the coupling means is achieved by reflection by the metal plate.
) circular polarization/linear polarization converter. (3) The circular polarization according to claim (1) or (2), wherein the coupling means comprises a metal pole inserted into the waveguide through an opening provided in a side surface of the waveguide. wave/linear polarization converter. (4) The coupling means includes a rectangular waveguide attached to the side surface of the waveguide, and a substantially rectangular opening provided on the side surface of the waveguide located at the opening of the rectangular waveguide. The circularly polarized wave/linearly polarized wave converter according to claim (1) or (2). (5) The mounting position of the coupling means from the end face of the waveguide is set to approximately 1/4 of the wavelength of the longer electromagnetic wave in the pipe, and the mounting position of the coupling means and the tip of the metal plate is 3. The circularly polarized wave/linearly polarized wave converter according to claim 2, wherein the wavelength within the tube is approximately 1/4 of the wavelength of the shorter electromagnetic wave. (6) The phase circuit is made of a dielectric plate, and the coupling means is oriented so that the angle between the dielectric plate and an extension of the center of the coupling means is about 45 degrees when viewed from a cross section parallel to the opening of the waveguide. Claims (1), (2), (3), (
4) or the circularly polarized wave/linear polarized wave converter described in (5). (7) Claims (1) and (7) characterized in that a metallic coating film is applied to the surface of the dielectric material so that it also serves as the metal plate.
2), (3), (4), (5), or (6) the circularly polarized wave/linear polarized wave converter. (8) The phase circuit is made of a metal block, and the metal block is attached so that at least one arc of the inner surface of the waveguide becomes a plane, and an extension line of the plane and an extension line of the center of the coupling means Claim (1) characterized in that the angle is oriented at about 45 degrees when viewed from a cross section parallel to the opening of the waveguide.
The circularly polarized wave/linearly polarized wave converter according to (2), (3), (4) or (5). (9) the phase circuit consists of a plurality of metal screws, each screw is attached to the center of an opposing circular arc on the inner surface of the waveguide so that the tip of the screw is directed toward the center of the waveguide;
Claim (1) characterized in that the angle between the center line connecting the opposing screws and the extension line of the center of the coupling means is about 45 degrees when viewed from a cross section parallel to the opening of the waveguide. ,(
2), (3), (4), or the circularly polarized wave/linear polarized wave converter described in (5). (10) The phase circuit consists of two metal plates, each of which is attached to the center of an opposing circular arc on the inner surface of the waveguide so that the short side of the metal plate is directed toward the center of the waveguide. Claim: wherein the angle between the center line connecting the opposing metal plates and the extension line of the center of the coupling means is about 45 degrees when viewed from a cross section parallel to the opening of the waveguide. (1
), (2), (3), (4) or (5). (11) The phase circuit consists of a section parallel to the opening of the waveguide that is transformed into an ellipse, and the angle between the center line connecting the two centers of the ellipse and the extension line of the center of the coupling means is guided. Claims (1), (2), (3), and (4) characterized in that the wave tube is oriented at approximately 45 degrees when viewed from a cross section parallel to the opening of the wave tube.
) or the circularly polarized wave/linearly polarized wave converter described in (5).