DE2216802A1 - REELABLE AND FLEXIBLE RECTANGULAR CONDUCTOR FOR TRANSMISSION OF ELECTROMAGNETIC WAVES - Google Patents

Description

SIEMEFS AKTIEITGESElLSeHAi ¹ S Munich 2, the - 7th APHL197

Berlin and Munich Wittelsbacherplstz 2

VPA

72/6558 22168Q2

Windable and bendable rectangular waveguide * "for the transmission of electromagnetic waves _t __

Addition to patent P 1 939 317 (VPA 69/2703)

The invention relates to a windable and bendable rectangular waveguide in which the outer contours the broad sides and narrow sides are each drawn in towards the middle, preferably in the shape of a circular arc, and in which the different wall thicknesses caused by these indentations is chosen in the circumferential direction of the waveguide cross section that when the waveguide is curved in the Cross-sectional plane lying but outside the inner contour Occurring opposing torques arise, which together with bending torques in the same sense cancel the rotary action of the other moments causing the cross-sectional deformation, so that when bending of the waveguide an optimal shape accuracy of the waveguide cross-section is achieved, as in the main patent specified.

Such waveguides are in particular used as a connecting line between the antenna and the transceivers intended for directional radios with radio frequencies above 3 GHz. It is known this Waveguide lines from subsections, namely straight waveguides, bends and twisting pieces

VPA 9/641/2018 Wed

Now independent patent application

309842/0653

build, with these parts manufactured in the factory and on Assembly site. Often, however, there are deviations from the actual local ones Dimensions or changes that may be required so that the prefabricated parts are no longer ' fit together and special lengths of waveguide cross-sections and fittings can be reproduced have to.

In the main patent, a solution was already given for a waveguide that would replace the existing one at the installation site Can be adapted to the structural conditions and at least the same transmission quality like the previously used rigid waveguide lines. This waveguide has one Cross-sectional profile that, when bending and twisting around its longitudinal axis, optimum shape accuracy of the waveguide cross-section is achieved. A waveguide of greater length can thus be produced are brought to the assembly site in the rolled up state and there during assembly is adapted by bending or bending and twisting the intended line routing.

The invention is based on the object of such a waveguide according to the main patent in Way to improve that while maintaining the optimal dimensional accuracy of the waveguide cross-section when bending and twisting the required moments are minimized.

YPA 9/641/2018 - 3 -

309842/0653

This object is achieved with a waveguide of the type described at the outset in such a way that that the broad sides of the waveguide are extended so far beyond the narrow sides, that, based on the individual narrow side and the individual quadrants of the waveguide cross-section, each an at least approximately symmetrical T-profile and, based on the single broad side, a strongly asymmetrical T-profile is created.

The shape of the waveguide cross-section is faithful to the shape of the waveguide cross-section due to the design corresponding to the selected wall thickness profile when bending the waveguide in the H and Ε planes and when twisting around its longitudinal axis guaranteed and in particular when bending in the Ε-plane (x-x-plane) a very low section modulus is achieved. Due to the With this waveguide a small cross-section height results when bending in the Ε-plane at equal mechanical strains in the outermost paser smaller radii of curvature than in known ones Waveguides. By curving in the Ε-plane and by twisting with a likewise small amount Torsional moment can therefore only be implemented with small radii of curvature. The simple geometric outer contour of the waveguide is also advantageous, as a result of which Die, plugs and fasteners for the waveguide can be simplified and the machining of the flanging can be made easier.

VPA 9/641/2018 - 4 -

309842/0653

Another advantageous embodiment of the subject matter of the invention is the thickness of the waveguide wall in the plane determined by the individual narrow side chosen so that they the

Condition M ~ h- (T satisfies, where M is the one to be compensated Torque, h is the thickness of the waveguide wall and 6 ~ the maximum allowable bending stress in the material used for the waveguide wall. This dimensioning increases the cost of materials for the waveguide with sufficient stability in an advantageous V / ise reduced, whereby the effort required for bending and twisting is also reduced and the assembly of the waveguide is made easier will.

It is also advantageous if the cantilever arms forming the extension of the broad sides at least in the area continuing the outer contour of the broad sides parallel to the inner waveguide broad sides get lost. This favorable for maintaining the dimensional accuracy of the waveguide cross-section Shaping also results in good, positionally secure bearing surfaces and when the waveguide is wound up allows the use of simple bending tools, with the help of which the waveguide at the installation site Achieving the intended cable routing bent and is twisted.

In addition to the aforementioned advantages for a rectangular waveguide according to the invention of course also those already for

VPA 9/641/2018 - 5 -

309842/0653

a waveguide according to the main patent listed, namely the possibility of direct connection of the bendable rectangular waveguide with the usually a rectangular cross-section having hollow conductor components or with the rigid rectangular hollow pipes, 'without that waveguide transitions must be used. Compared to the rigid hollow pipe there is the Advantage of falling elbows and twisting pieces and spacers as well as significant savings in planning time and assembly costs.

The invention is explained in more detail below on the basis of an exemplary embodiment.

The figure shows a cross section of a waveguide with rechteckförmigea internal cross-section and a suitably profiled _Au3enkontur} is preferably made of a soft, electrically highly conductive material, in particular aluminum, and manufactured by the extrusion, may be used. When the waveguide is curved in the bending plane xx, tensile and compressive stresses are caused parallel to the bending plane, which result in forces q perpendicular to the bending plane deform the waveguide contour. As

VPA 9/641/2018 - 6 -

309842/0653

The cross-sectional deformation can be proven by calculation the cross-sectional area can be controlled. Given a rectangular or any waveguide inner contour, a minimum is required Cross-sectional deformation achievable when the outer contour is chosen so that when it is curved of the waveguide torques H arise which, together with the torque Mq, the rotary effect of moments M cancel.

BpI the waveguide according to the invention are the Outer contours of the broad sides 1 and the narrow sides 2, each drawn in towards the middle, preferably in the shape of an arc of a circle, so that a different shape caused by these indentations Wall thickness arises in the circumferential direction of the waveguide cross-section. The broadsides 1 of the Waveguides are each extended beyond the narrow sides 2 to form so-called cantilever arms 3. These extensions are designed and dimensioned so that, based on the individual Narrow side and the individual quadrants of the waveguide cross-section, each at least one approximately symmetrical T-profile and, in relation to the individual broad side, a strongly unsjtiraetric one T-profile is created. There are two conditions for the design and dimensioning of the cantilever arms: On the one hand, the bending stresses caused by the moments in the cantilever arms are permitted Do not exceed the permissible value and other

VPA 9/641/2018 - 7 -

309842/0653

The broad sides of the waveguide must not bend beyond the permissible level.

From the two longitudinal sides of the cantilever arms 3, ie the sides running in the direction of the broad sides of the waveguide, at least the side continuing the outer contour of the broad sides 1 runs parallel to the inner waveguide broad sides. At their end, the cantilever arms 3 are rounded and preferably merge in an arc shape into the outer contour of the narrow sides 2, which is drawn in towards the center. As a result, a material balance is again established; because whatever material was removed at the end of the cantilever arm is added again at the transition points from the broad side to the cantilever arm, so that the cross-sectional area content that is effective for the counter torques is retained. In the area of the cantilever arms 3, when the waveguide is bent, counter-torques M occur which lie in the cross-sectional plane but occur outside of the inner diameter. λ with the torque en M ₁ - bending in the same sense. cancel the rotary action of the other moments M causing the cross-sectional deformation. The thickness h of the waveguide wall of the broad sides in the plane determined by the individual narrow sides is preferably dimensioned to a minimum permissible value, which advantageously results in a reduction in the cost of materials and also in the amount required

VPA / 641/2013 - 8

309842/0653

Moments when bending is reached. In the present case, the thickness of the waveguide wall is chosen so that

2
it satisfies the condition M ″ -h CT. M denotes the torque to be compensated, h denotes the thickness of the waveguide wall on the broad side in the plane of the narrow side and 6T denotes the maximum allowable bending stress in the material used for the waveguide wall from bending

1 depends on radius, for example, C = -r. The strenght

the waveguide wall is then at least so large, preferably, but not significantly larger, that

_h 2

the condition M = ·? * - · 6 "is fulfilled. The one shown in the figure Rectangular waveguide is shown to scale, so that the dimensions correspond to the true size ratio correspond.

5 claims
1 figure

VPA 9/641/2013 - 9 -

309842 / 06S3

Claims (2)

Claims 2216802 1.jWindable and bendable rectangular waveguide, at which the outer contours of the broad sides and narrow sides are drawn in towards the middle, preferably in the shape of a circular arc, and in which the different wall thicknesses caused by these indentations is chosen in the circumferential direction of the waveguide cross-section such that when the waveguide is curved Counter torques occurring in the cross-sectional plane but outside the inner contour arise which together with torques bending in the same sense, the rotary action of the others, the cross-sectional shape Cancel causing moments, so that when the waveguide is bent, the waveguide cross-section is optimally true to its shape is achieved, according to patent P 19 39 317 (VPA 69/2703), characterized in that that the broad sides (1) of the waveguide are extended beyond the narrow sides (2) so far that, based on the individual narrow side (2) and the individual quadrants of the waveguide cross-section at least approximately symmetrical T-profile and, based on the individual broad side (1), a strongly asymmetrical one T-profile is created. 2. Rectangular waveguide according to claim 1, characterized characterized in that the thickness of the waveguide wall of the broad side in the by the individual Narrow side (2) certain level is chosen so that it satisfies the condition M - h (F, v / orin M the torque to be compensated, h the thickness of the waveguide wall of the broad side and CT is the maximum allowable bending stress in the for the Waveguide wall is the material used. YPA 9/641/2018 - 10 - 309842/0653 Rectangular waveguide according to Claim 1 or 2, characterized in that the extension the cantilever arms (3) forming the broad sides (i) at least in the one continuing the outer contour of the broad sides (1) Area parallel to the inner waveguide broad sides. VPA 9/641/2018 309842/0653