JPH05121912A - Cylindrical waveguide/square waveguide converter - Google Patents

Abstract

PURPOSE:To facilitate fine-adjustment of the converter after its manufacture by joining a square waveguide to a side face of a cylindrical waveguide, inserting a probe for electromagnetic wave coupling into the cylindrical waveguide along the guide axis of the square waveguide and changing the position and the length of the probe. CONSTITUTION:A cylindrical waveguide 10 and a square waveguide 11 are joined at a position by a distance L being an odd number of multiple of a 1/4 wavelength of an electromagnetic wave propagated toward an opening R1 from a termination plate 13 in a cylindrical waveguide 10 so that both axes are made orthogonal. Then a conductive needle probe 12 is inserted in the waveguide 10 while keeping insulation with an insulation material 14 along the guide axis of the waveguide 11. Moreover, a conductive needle probe 12 is extended in the aperture direction of the waveguide 11 along the guide axis of the waveguide 11 and a tip of the probe 12 is folded in parallel with a short side 11b of the waveguide 11 at a position by a distance (m) being an odd number multiple of 1/4 wavelength of an electromagnetic wave propagated to the waveguide 11 from an outer wall of the waveguide 10. The folded length m' is selected to be a length within a range not in contact with the guide wall of the waveguide 11 to emit an electromagnetic wave efficiently in the waveguide 11. Thus, fine-adjustment after manufacture is easily implemented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave propagation means having a structure in which a rectangular waveguide is joined to a circular waveguide and fine adjustment can be easily performed after fabrication.

[0002]

2. Description of the Related Art As shown in FIG. 5, the central axis of a circular waveguide 21 is made orthogonal to the central axis of the rectangular waveguide 22 on the long side tube wall of the rectangular waveguide 22 whose one end is terminated. One end of the circular waveguide 21 is joined. A rectangular coupling slit 23 is provided at approximately the center of the wall of the rectangular waveguide 22 surrounded by the circular waveguide 21.
The electromagnetic wave propagating in the circular waveguide 21 via the coupling slit 23 is propagated in the rectangular waveguide 22.

[0003]

The waveguide circular / square converter is generally manufactured by die casting.
It was difficult to make corrections after manufacture, especially fine adjustment of the through holes. According to the present invention, the electromagnetic wave of the circular waveguide is propagated to the rectangular waveguide via a wire-shaped probe to facilitate fine adjustment of the coupling of the electromagnetic wave.

[0004]

[Means for Solving the Problem] One end of the circular waveguide is terminated, and the central axis of the rectangular waveguide is made orthogonal to the central axis of the circular waveguide so that the circular waveguide is formed on the side surface of the circular waveguide. One end of the rectangular waveguide is joined, and an electromagnetic wave coupling probe is inserted into the circular waveguide. The probe is extended into the rectangular waveguide by penetrating the wall of the circular waveguide, and the tip of the probe is bent in the rectangular waveguide parallel to the short side of the rectangular waveguide to form a rectangular waveguide. Use an electromagnetic wave radiator inside the wave tube so that fine adjustment is easy.

[0005]

[Function] Circular waveguide 10 for electromagnetic waves propagating in TE11 mode
The electric field distribution inside the circular waveguide 10 is as shown in FIG.
Of the same circular shape due to the interference of the electromagnetic waves propagating in the circular waveguide 10 and the electromagnetic waves reflected by the terminal plate 13 of the circular waveguide 10 of the same circular shape. A standing wave is generated in the waveguide 10.

The standing wave in the circular waveguide 10 has a maximum electric field amplitude at a position that is an odd multiple of a quarter wavelength of an electromagnetic wave propagating in the opening direction from the end surface of the circular waveguide 10. , And can be taken out as an electric signal by being coupled to the metal probe 12 arranged at the same position and parallel to the same electric field direction.

A rectangular waveguide in which the probe 12 penetrates the side surface of the circular waveguide 10 and is joined to the side surface of the circular waveguide 10.
11 of the probe 12 at the position of an odd multiple of a quarter wavelength of the electromagnetic wave propagating from the side of the circular waveguide 10 inside the rectangular waveguide 11 of the same rectangular waveguide 11. It is bent so that it is parallel to the short side 11a, and the electromagnetic wave is re-radiated from the same tip into the rectangular waveguide 11.

The electromagnetic wave re-radiated in the rectangular waveguide 11 becomes an electric field of TE10 mode shown in FIG. 2B and propagates in the rectangular waveguide 11. The propagation of electromagnetic waves from the circular waveguide 10 to the rectangular waveguide 11 is reversible,
Electromagnetic wave propagation from 11 to the circular waveguide 10 is also possible as described above.

A second rectangular waveguide 18 which is perpendicular to the tube axis direction of the rectangular waveguide 16 joined to the circular waveguide 15 as shown in FIG. By providing the waveguide 18 with the same probe 19 as described above, if the electromagnetic wave input to the circular waveguide 15 is a TE11 mode linearly polarized wave, it can be either vertically or horizontally polarized electromagnetic wave. The respective polarized waves can be separated and extracted by coupling them to the probes 17 or 19 parallel to the electric field direction of.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in the perspective view of the main part of a circular waveguide / rectangular waveguide converter shown in FIG. 1, one end of a circular waveguide 10 is terminated by a conductive metal plate 13, and the same circular waveguide is used. A position that is an odd multiple of a quarter wavelength of an electromagnetic wave propagating in the circular waveguide 10 from the surface of the terminal plate 13 inside the circular waveguide 10 to the opening side of the circular waveguide 10, that is, the distance shown in FIG. At the position of L, the rectangular waveguide 11 is joined to the side surface of the circular waveguide 10 so that the central axis of the circular waveguide 10 and the tube axis of the rectangular waveguide 11 are orthogonal to each other.

A wire-shaped probe 12 made of highly conductive metal is attached to the circular waveguide 10 along the tube axis of the rectangular waveguide 10.
Of the circular waveguide 10 is inserted into the circular waveguide 10 while maintaining the insulating state by the side surface of the circular waveguide 10 and an insulating material 14 such as Teflon. The insertion depth l ′ of the probe 12 into the circular waveguide 10 is set to a length at which the electromagnetic wave input to the circular waveguide 10 is efficiently coupled to the probe 12, and if necessary, after the length is produced. Make fine adjustments.

Further, the probe 12 includes the circular waveguide 10
It goes without saying that it is inserted in a direction orthogonal to the central axis of the circular waveguide 10 at a position having a distance L from the end surface of the circular waveguide 10 in the opening direction of the circular waveguide 10. The probe 12 also extends in the opening direction of the rectangular waveguide 11 along the tube axis of the rectangular waveguide 11, and the electromagnetic wave that propagates from the outer wall of the circular waveguide 10 to the rectangular waveguide 11. The tip of the probe 12 is bent in a direction parallel to the short side 11b of the rectangular waveguide 11 at a position that is an odd multiple of a quarter wavelength, that is, at a position of the distance m in FIG.

The length m'of the bent portion of the probe 12 in the rectangular waveguide 11 is within a range in which the tip of the probe 12 does not contact the tube wall of the rectangular waveguide 11. The length of the electromagnetic wave is efficiently radiated in 11
If necessary, fine adjustment may be performed after manufacturing together with the portion parallel to the tube axis. Also, the thickness of the probe 12 is the same as the length thereof, and is replaced with a probe of another thickness after production, if necessary.
You may adjust.

The circular waveguide 10 has a diameter that provides a cutoff frequency lower than the frequency of the electromagnetic wave to be transmitted. That is, assuming that the inner diameter of the circular waveguide 10 is R1 (mm), the frequency of the electromagnetic wave to be transmitted is f (GHz), and the cutoff frequency of the circular waveguide 10 is F0 (GHz), the TE11 mode electromagnetic wave is transmitted. In the circular waveguide, the condition of f> F0 = 300 / (3.412 × R1 / 2) is satisfied. Further, in the rectangular waveguide 11 that transmits the TE10 mode electromagnetic wave, f> F1 = 300 / (2 ×) where the long side 11a of the rectangular waveguide 11 is a (mm) and the cutoff frequency is F1 (GHz). a).

For example, the inner diameter R1 (mm) of the circular waveguide 10
Also, the length a (mm) of the long side 11a of the rectangular waveguide 11 is set to a small value for cost and size reduction within the range satisfying the above two equations, but the transmission loss rapidly increases near the cutoff frequency. F / F0 ≈f / F1 ≈1.6, and the ratio of the long side 11a to the short side 11b of the rectangular waveguide 11 is 2: 1.

In the example shown in FIG. 3, the circular waveguide 15 is extended,
In the same manner as described above, the first rectangular waveguide 16 is joined, and the central axis of the circular waveguide 15 is made orthogonal to the axial direction of the rectangular waveguide 16 so that the central axis of the circular waveguide 15 is orthogonal to the second rectangular waveguide 16. Join the wave tubes 18,
The probe 19 of the rectangular waveguide 18 is provided under the same conditions as the probe 12 of the rectangular waveguide 11.

The circular waveguide of the second rectangular waveguide 18
The mounting position with respect to 15 is such that an electromagnetic wave propagating in the circular waveguide 15 has a tube axis of the rectangular waveguide 18 from the inner surface of the terminal plate 20 of the circular waveguide 15 in the opening direction of the circular waveguide 15. The positions are separated by an odd number of quarter wavelengths. Therefore, the probe 17 of the first rectangular waveguide 16 and the probe 19 of the second rectangular waveguide 18
Are orthogonal to each other in the circular waveguide 15, and the mutual intervals on the central axis of the circular waveguide 13 are the same.
Is an odd multiple of a quarter wavelength of the electromagnetic wave propagating through.

As for the positional relationship between the rectangular waveguides 16 and 18 with respect to the terminal plate 20 of the circular waveguide 15, the second rectangular waveguide 18 is farther from the terminal plate 20 than that shown in FIG. position,
Further, the rectangular waveguide 16 may be located near the terminal plate 20. If the lengths of the probes 17 and 19 in the circular waveguide 15 are shorter than the radius of the circular waveguide 15, the rectangular waveguides 16 and 18 are the same with respect to the terminal plate 20. It may be the position.

[0019]

As described above, the coupling of electromagnetic waves in the circular waveguide and the rectangular waveguide changes depending on the position of the probe inserted in both waveguides and the length of each element portion of the probe. Since it is configured, fine adjustment can be easily performed after manufacturing.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of a circular waveguide / rectangular waveguide converter of the present invention.

FIG. 2 is a side sectional view (a) and a front sectional view (b) viewed from the opening side of the converter.

FIG. 3 is an electric field distribution diagram of the circular waveguide TE11 mode (a),
And (b) of the electric field distribution of the rectangular waveguide TE10 mode.

FIG. 4 is a partial cutaway perspective view of a circular waveguide / rectangular waveguide converter capable of separately extracting vertically polarized waves and horizontally polarized waves.

FIG. 5 is a partially cutaway perspective view of a conventional circular waveguide / rectangular waveguide converter.

[Explanation of symbols]

 10 Circular Waveguide 11 Rectangular Waveguide 11a Long Side of Rectangular Waveguide 11b Short Side of Rectangular Waveguide 12 Probe 13 End Plate of Circular Waveguide 14 Insulation Material 15 Circular Waveguide 16 Rectangular Waveguide 17 Probe 18 Second rectangular waveguide 19 Probe 20 End plate 21 Circular waveguide 22 Rectangular waveguide 23 Coupling slit

Claims (2)

[Claims] A TE11 mode electromagnetic wave propagating in the circular waveguide is propagated in the TE10 mode by propagating the rectangular waveguide with the central axis of the circular waveguide being orthogonal to the central axis of the circular waveguide. In the squeezing transducer, terminating one end of the circular waveguide,
The axis of the rectangular waveguide is made orthogonal to the center axis of the circular waveguide at a position that is an odd multiple of a quarter wavelength of the electromagnetic wave that propagates from the same end face in the opening direction of the circular waveguide. Bonding to the side of the same circular waveguide, penetrating the side of the same circular waveguide and inserting an electromagnetic wave coupling probe into the same circular waveguide along the tube axis of the same rectangular waveguide, A circular waveguide characterized in that the probe tip is bent parallel to the short side of the rectangular waveguide at a position that is an odd multiple of a quarter wavelength of the same electromagnetic wave from the side of the circular waveguide inside the tube / Rectangular waveguide converter. 2. The circular waveguide is orthogonal to the central axis of the circular waveguide at a position that is an odd multiple of a quarter wavelength of an electromagnetic wave propagating in the opening direction of the circular waveguide from the end surface of the circular waveguide. The second rectangular waveguide having a tube axis perpendicular to the tube axis of the rectangular waveguide is joined and penetrates the side surface of the circular waveguide along the tube axis of the second rectangular waveguide. Insert a probe for electromagnetic wave coupling into the same circular waveguide, and guide the tip of the same rectangular waveguide from the side of the circular waveguide inside the same rectangular waveguide at an odd multiple of a quarter wavelength of the same electromagnetic wave. The circular waveguide / rectangular waveguide converter according to claim 1, wherein the circular waveguide / rectangular waveguide converter is bent parallel to a short side of the tube.