DE1028639B - Waveguide section short-circuited on one side, which is provided with a device for connecting a coaxial line - Google Patents

Description

GERMAN

The invention relates to a waveguide section short-circuited at one end, which is provided with a device for connecting a coaxial line is provided in such a way that the inner conductor of the coaxial line is guided like a probe into the waveguide interior and at its end an extended approach carries, which is limited by a preferably circular end face.

Such arrangements, which are known for example from British patents 612,409 and 635,763 are generally electrically satisfactory only over a relatively narrow frequency band !properties. To such arrangements, with approximately the same electrical properties, in one To be able to use other frequency bands with different frequencies, one has therefore switched to to train the transition as such to be tunable. This is usually done in such a way that the Probe is designed to be variable in its immersion depth into the interior of the waveguide. Is different Attempts have also been made to ensure the matching in the frequency-different frequency bands by that the probe, possibly remaining unchanged in its immersion depth, in its immersion location is designed to be adjustable in the hollow pipe. However, none of these solutions are constructively satisfactory and easily give rise to mechanical disturbances.

The invention is based on the object of providing a way in which it is possible to do this Encounter difficulties.

According to the invention, this object is achieved in such a way that several in the immersion depth in the Inner waveguide changeable, closely spaced tuning screws in the wall of the waveguide are arranged such that they face the end face of the inner conductor attachment.

The transition according to the invention has the advantage over the known designs that "to its tuning only arranged tuning screws in the waveguide wall are operated must, with both the inner conductor of the coaxial line and the short circuit of the waveguide stationary are trained. This significantly simplifies the design and the size of the Transition, especially the length, greatly reduced. In addition, the electrical properties of the transition are so favorable that compared to the known designs with the same bandwidth the reflections are significantly lower or at the same tolerated reflection factor, the bandwidth is significantly larger. For example, it is appropriate Setting possible, the transition to wide-area radio systems also for multiple channels too

Waveguide short-circuited on one side

section with a fixture

for connecting a coaxial line

is provided

Applicant:
Siemens & Halske Aktiengesellschaft,

Berlin and Munich,
Munich 2, Wittelsbacherplatz 2

Dipl.-Ing. Albert Kurzl, Munich-Lochhausen,
has been named as the inventor

without having to tune to the individual channels.

A preferred embodiment of a tunable transition according to the invention is shown in FIG Drawing shown. It represents

1 shows a longitudinal section through the entire tunable transition for the case of a rectangular waveguide dar while

Fig. 2 shows a modification of the inner conductor approach of the coaxial line.

The rectangular waveguide section I _1, which is shown in FIG. 1 in a section parallel to its narrow side walls through the waveguide axis, can be connected to a hollow line by means of a flange 2. The coaxial line formed from the inner conductor 3 and the outer conductor 4 opens into the waveguide section 1 in such a way that the two line axes are perpendicular to one another. The inner conductor 3 of the coaxial line is extended in such a way that it protrudes into the interior of the waveguide 1 like a probe. Its axis is parallel to the direction of the electric field lines in the waveguide 1.

The inner conductor 3 of the coaxial line is designed so that it has a widened approach at its end carries that against the interior of the waveguide section 1 by a perpendicular to the axis of the inner conductor 3, opposite the cross-sectional area of the inner conductor 3 enlarged, preferably circular end face 16 is limited.

As can be seen from the figures, the approach consists of an actual extended part 5 or 6 and a shaft 7 or 8, which is preferably provided with a thread and in the end face of the inner conductor 3 of the coaxial line screwed and

809 507/271

is secured against rotation with a lock nut 9. The shaft 7 or 8 of the inner conductor approach of the The coaxial line is designed with a smaller diameter than the inner conductor 3 itself. That is It is therefore useful because of the relatively large capacitance between the inner conductor attachment of the coaxial line and allows the waveguide wall to reduce the depth of penetration of the extended inner conductor 3, which However, a reduction in the inductance at the transition point has the consequence, which by reduction the diameter of the elongated inner conductor 3 must be compensated again to the Transformation of the wave resistance of the coaxial line to the waveguide not to disturb.

A preferred embodiment of the inner conductor approach of the coaxial line is shown in Fig. 1, the expanded part of the approach from a flat plate 5, whose facing towards the interior of the waveguide section 1 boundary surface 16 shows the enlarged end face of the elongated inner conductor 3 of the coaxial line. The Plate 5 may be provided with a screwdriver slot 10 for easier assembly of the approach, the screwing into a correspondingly arranged, end-face hole in the inner conductor 3 is facilitated.

Fig. 2 shows a further preferred embodiment of the approach 2, in which the extended part consists of a full cone-6, the base of which 16 corresponds to the boundary surface 16 of the flat plate 5. The opening angle α is preferably here over 40 °.

The hollow line is at a fixed distance from the transition cross-section that is dependent on the frequency range terminated by a fixed short circuit, which, as shown in Fig. 1, by a to the waveguide 1 soldered short-circuit plate 11 is achieved. The matching of the transition flat of the invention takes place within the given frequency band by actuation of closely spaced tuning screws 12, which are in a row parallel to the Waveguide axis arranged in this way in the waveguide wall are that they face the end face 16 of the inner conductor approach. By setting the The penetration depth of one or more of these screws can have the same effect in a manner known per se can be achieved as with a tuning screw, which is adjustable both in its penetration depth and in Is displaceable in the direction of the longitudinal axis of the waveguide. Preferably, three tuning screws 12 guided in a socket 13, which is inserted into the wall of the waveguide 1 and by means of screws 14, which are offset from one another by 120 ° as in FIG. 1, for example, is attached. To an unintended To prevent adjustment of the tuning screws 12, the socket 13 is preferably with a cover 15 completed.

The mode of operation of the entire arrangement is special in terms of broadband and freedom from reflection favorable if the tuning screws 12 of the end face 16 of the inner conductor attachment of the coaxial line face spatially. Preferably, as shown in FIG. 1, the axis of the central one falls Tuning screw with the extension of the axis of the inner conductor 3 together.

The tunable transition according to the invention can also be used with advantage for hollow pipes with a different, for example circular, cross section. In the case of a waveguide with a circular cross section, the excitation conditions are given, for example, for the H ₁₁ wave.

Claims (5)

Patent claims: 1. Waveguide section fixedly short-circuited on one side which is provided with a device for connecting a coaxial line in the manner is that the inner conductor of the coaxial line is at a fixed distance from the short-circuit like a probe in the interior of the waveguide is guided and at its end carries an enlarged approach that passes through a preferably circular end face is delimited, characterized in that several Closely adjacent tuning screws that can be changed in the depth of immersion into the interior of the waveguide are arranged in the wall of the waveguide in such a way that they correspond to the end face of the inner conductor attachment face. 2. Arrangement according to claim 1, characterized in that the inner conductor attachment of the coaxial line has at its end a flat plate (5) which is perpendicular to the inner conductor axis. 3. Arrangement according to claim 1, characterized in that the inner conductor attachment of the coaxial line at its end has a full cone (6) with an opening angle of more than 40 °. 4. Arrangement according to one of the preceding claims, characterized in that a certain Piece of the inner conductor (3) of the coaxial line at the point where it joins the waveguide (1) is reduced to a smaller diameter 5. Arrangement according to one of the preceding claims, characterized in that in the Waveguide wall three tuning screws (12) are provided, which are parallel in a row are arranged to the waveguide axis that the axis of the middle tuning screw with the axis of the Inner conductor (3) coincides. References considered: British Patent Nos. 612,409, 635,763; G. C. Southworth, "Principles and Applications of Wave Guide Transmission," New York, 1954, p. 257. 1 sheet of drawings 809 507/271 4.58