RU2799560C1 - Compact coaxial waveguide adapter of the probe type - Google Patents

Abstract

FIELD: microwave technology.

SUBSTANCE: invention is related to compact coaxial waveguide transitions of the probe type. The coaxial waveguide transition contains a section of regular waveguide 1, shorted by end wall 2, and a section of coaxial line 3 located perpendicular to it, which is laid along the inner side of the wide wall of the regular waveguide. The coaxial line at the entrance to the waveguide and at its end inside the waveguide along the outer metal shell is galvanically connected to the wall of the waveguide, for example, by soldering. Cylindrical probe 4 is connected to the central conductor of the coaxial line at the end of the line located inside the waveguide, parallel to the electric field inside the waveguide, while the axis of the probe is perpendicular to the axis of the coaxial line. The distances from end wall 2 to probe 4, from the ends of probe 4 to the wide walls of the waveguide, and from the cylindrical surface of probe 4 to the metal sheath of coaxial line 3 inside the waveguide are selected according to the minimum reflection coefficient of the transition as a whole.

EFFECT: simplification of the design of coaxial waveguide transition and the possibility of implementing the most compact coaxial waveguide transition with a parallel arrangement of the waveguide and the coaxial line.

1 cl, 2 dwg

Description

The present invention relates to microwave technology and can be used as a matched transition between a coaxial line and a regular waveguide.

Known coaxial-waveguide transition US4463324A, which is a segment of a rectangular waveguide connected to a coaxial line through a probe parallel to the electric field inside the waveguide.

The disadvantages of such a coaxial-waveguide transition are:

- the transition is not coaxial, since the coaxial line enters the waveguide through the waveguide flange, and not through the end wall;

- the absence of any possibility of setting the transition in the manufacturing process.

Known coaxial-waveguide transitions RU2011245C and RU2678924C1, which is a segment of a rectangular waveguide connected to a coaxial line through a loop perpendicular to the magnetic field inside the waveguide.

The disadvantages of these coaxial-waveguide transitions are:

- lack of galvanic isolation of the central conductor of the coaxial line from the wall of the waveguide;

- large dimensions of transitions;

- the absence of any possibility of setting the transition in the manufacturing process.

The closest in technical essence to the proposed solution is a coaxial-waveguide transition RU2517678C1, containing a segment of a coaxial line, a segment of a regular waveguide shorted by an end wall, a coupling element, a matching element made in the form of several structurally combined rectangular parallelepipeds, and the base of the lower rectangular parallelepiped, which is the base of the matching element is associated with the wall of a segment of a regular waveguide perpendicular to the direction of the vector E, and the base of each next rectangular parallelepiped is associated with the upper plane of the previous rectangular parallelepiped, and the width and length of each next rectangular parallelepiped is equal to or less than the width of the previous rectangular parallelepipeds facing the end wall of the regular waveguide segment are located in the same plane, and the upper and side walls of the matching element are located at a distance from the walls of the regular waveguide segment, and the matching element is connected to the coaxial line through the coupling element, in the wall of the matching element facing the end On the wall of the regular waveguide segment, located at some distance from the end wall of the regular waveguide segment, a coupling hole is made, in which the coupling element is installed coaxially, connecting the matching element with the central conductor of the coaxial line, located perpendicular to the end wall of the regular waveguide segment and coaxially with the coupling element, and the transverse dimensions of the coupling hole in the matching element are greater than the transverse dimensions of the coupling element, and the axis of the coaxial line segment is located in the symmetry plane of the matching element, coinciding with the symmetry plane of the regular waveguide segment and the maximum of the vector E.

The disadvantages of such a coaxial-waveguide transition are the large dimensions of the transition, as well as the absence of any possibility of setting the transition during the manufacturing process.

The author was faced with the task of creating a coaxial-waveguide transition, devoid of the listed disadvantages of the prototype.

This problem is solved due to the fact that the coaxial-waveguide transition contains a segment of a regular waveguide shorted by the end wall, and a segment of the coaxial line located perpendicular to it, which is laid along the inner side of the wide wall of the regular waveguide. The outer conductor of the coaxial line at the entrance to the waveguide and at its end inside the waveguide is galvanically connected to the wall of the waveguide. A cylindrical probe parallel to the electric field inside the waveguide (perpendicular to the axis of the coaxial line) is attached to the central conductor of the coaxial line at the end of the line located inside the waveguide. The distances from the end wall to the probe, from the ends of the probe to the wide walls of the waveguide, and from the cylindrical surface of the probe to the metal sheath of the coaxial line inside the waveguide are selected according to the condition of the minimum reflection coefficient from the junction as a whole.

The technical result of the invention is to ensure the minimum dimensions of the transition, as well as galvanic isolation between the central conductor of the coaxial line and the matching element, simplify the design of the coaxial-waveguide transition, the possibility of implementing a coaxial-waveguide transition with a parallel arrangement of the waveguide and the coaxial line and the possibility of customization in the manufacturing process.

The inventive coaxial-waveguide transition has a set of essential features not known from the prior art for products of this purpose, which allows us to conclude that the invention meets the criterion of "novelty".

The claimed coaxial-waveguide transition, according to the applicant and the author, meets the criterion of "inventive step", since for specialists it does not explicitly follow from the prior art, that is, it is not known from available sources of scientific, technical and patent information at the date of filing the application.

The essence of the invention is illustrated with the help of drawings, where:

- in Fig. 1 shows a cross section of a coaxial-waveguide transition;

- in Fig. 2 shows a coaxial-waveguide transition with a segment of a regular circular waveguide.

The coaxial-waveguide transition contains a section of a regular waveguide 1, shorted by the end wall 2, and a section of the coaxial line 3 located perpendicular to it, which is laid along the inner side of the wide wall of the regular waveguide. The outer conductor of the coaxial line at the entrance to the waveguide and at its end inside the waveguide is galvanically connected to the wall of the waveguide. A cylindrical probe 4 parallel to the electric field inside the waveguide (perpendicular to the axis of the coaxial line) is attached to the central conductor of the coaxial line at the end of the line located inside the waveguide. The distances from the end wall 2 to the probe 4, from the ends of the probe 4 to the wide walls of the waveguide, and from the cylindrical surface of the probe 4 to the metal sheath of the coaxial line 3 inside the waveguide are chosen according to the condition of the minimum reflection coefficient from the transition as a whole.

The device works as follows.

The microwave signal from the segment of the coaxial line 3 is fed to the coupling element 4 in the form of a probe, which is a continuation of the central conductor of the segment of the coaxial line 3. The coupling element 4, located at the end of the central conductor of the coaxial line, transforms the TEM wave in the coaxial line into the wave H ₁₀ of the waveguide and simultaneously matches the wave impedances of the waveguide and the coaxial line. Setting the transition in the manufacture of frequency to a minimum of the reflection coefficient can be carried out by moving the coaxial line along its axis, followed by fixing it using, for example, soldering. The device is mutual.

On FIG. 1 and FIG. 2 shows as an example the main dimensions for the transition from a rectangular waveguide with a cross section of 23 × 10 mm to a coaxial cable PK50-2-25. The transition has VSWR≤1.2 in the 10% band and the value of the transition attenuation is not more than 0.2 dB.

Claims (1)

A compact coaxial-to-waveguide junction of a probe type, containing a segment of a coaxial line, a segment of a regular waveguide shorted by an end wall, and a probe parallel to the electric field inside the waveguide, characterized in that the coaxial line is laid along the wide wall of the waveguide parallel to the longitudinal axis of the waveguide, the outer conductor of the coaxial line at the entrance to the waveguide and at its end inside the waveguide, it is galvanically connected to the wall of the waveguide, the probe is made of a cylindrical shape and attached to the central conductor of the coaxial line at the end located inside the waveguide, and the transition during manufacture is adjusted in frequency to the minimum of the reflection coefficient by moving the coaxial line along its axis with its subsequent fixation.

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