DE1191451B - Dielectric support for inner conductors of coaxial systems - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

HOIb

German KL: 21c-5/03

Number: 1191451

File number: R 32179 VIII d / 21 c

Filing date: February 27, 1962

Opening day: April 22, 1965

The invention relates to a dielectric support for inner conductors of coaxial systems, whose Characteristic impedance in the area of the support by corresponding modification of the inner conductor and / or Outer conductor diameter is adapted to the adjacent pillarless coaxial sections.

It has been shown that such supports can be used for many purposes, particularly in the case of high-frequency connectors in the maximum frequency range, still have too large reflection factors. It is already known to provide circular openings in such supports. This known measure brings however, it does not entail the intended reduction in the reflection factor. In addition, these result in well-known Breakthroughs always oblique overlaps between the separating lines dielectric / air and the oneself electric field lines extending between inner and outer conductors. Such supports can therefore cannot be calculated exactly, but must always be determined experimentally, which is extraordinary is troublesome and incomplete, as those caused by the breakthroughs and those caused by the transition zone Field distortions caused between undisturbed and dielectric-filled line sections cannot be separated.

There are also supports already known, which consist of a relatively thin disc on which radially extending spoke-like stiffening ribs are formed on the end face. In the latter known Column, the wave resistance of the entire column is not related to the wave resistance of the adjoining Supportless coaxial areas adapted, but it is ■ only by appropriate shaping of the support end faces a certain adaptation of the support face to the course of the electric field lines in the plane of the disc is provided.

There are also already known support washers, which consist of a thin membrane, which with provided annular bead-like edges and is supported by them on the inner or outer conductor. Farther a coaxial is known in which the inner conductor on sector-shaped foam supports on the outer conductor is supported. However, there is no measure here

Dielectric support for inner conductors from
Coaxial systems

Applicant:
Rohde & Schwarz,

Munich 8, Mühldorfstr. 15th

Named as inventor:
Dipl.-Ing. Franz Reinhold Huber,
Neu-Keferloh near Munich;
Dipl.-Ing. Heinrich Neubauer,
Unterhaching near Munich

intended to adapt the wave resistance of the support to the surrounding coaxial space.
The object of the invention is to create an anechoic support for coaxial lines which, even with the generally unavoidable relatively high dielectric constant of the support material, has a minimal effect on the electric field and which calculates its shape and dimensions in a simple manner for a given dielectric constant and given dimensions of the coaxial and can be produced.

Starting from a dielectric support, the wave resistance of which in the area of the support is determined by corresponding Modification of the inner conductor and / or outer conductor diameter to the adjacent columnless Coaxial section is adapted and in which openings in the area between the inner and outer conductors are provided, the invention proposes to solve this problem, the inner conductor surrounding ring part and two or more, preferably three, radially outwardly protruding and Support arms that are distributed approximately evenly on the circumference of the ring and are connected to it of circular sector-shaped outline, the longitudinal edges of which have radii. of the ring part collapse, where the ring part and the support arms are dimensioned according to the following formula:

Z = 60

In

1 1, d _s

In

In

d, I 2π 509 540/340

In this formula, Z denotes the wave resistance of the support, e _r the relative dielectric constant of the support material, Σ ^α the sum of the angular areas covered by the individual sector supports and d _x the outer diameter of the inner conductor, d _z the outer diameter of the ring part and d _s the inner diameter of the outer conductor .

The formation of the support according to the invention ensures that the edges of the openings are arranged either parallel or perpendicular to the electric field lines running between the inner and outer conductors. This results in clearly defined line sections with zones of full dielectric distributed over the cross section, which alternate with areas of a mathematically detectable layered dielectric, so that an almost completely reflection-free support can be calculated and constructed in a simple manner. The new support design also enables a larger design of the inner conductor diameter, which has been reduced for wave resistance adjustment, and in addition to the better electrical properties, the new support therefore also has the advantage of greater mechanical strength of the inner conductor, which also enables an increase in performance and also reduces dielectric losses .

The invention is explained in more detail below with reference to schematic drawings of an exemplary embodiment:

Z = 60-

In this formula, Z denotes the desired wave impedance of the coaxial line, e _r the relative dielectric constant of the support material used (dielectric constant of the air ε ₀ = 1) and Σ <* the sum of all the angular ranges covered by the individual support disks. Furthermore, d _x denotes the outside diameter of the inner conductor in the area of the support or the inside diameter of the support ring part, d _% the outside diameter of the support ring part and d _% the inside diameter of the outside conductor of the coaxial line in the area of the support.

F i g. Fig. 1 shows a support according to the invention in plan view;

F i g. Figure 2 shows a section through the support of Figure 1, essentially along the line I-I of Fig. 1.

The new support made of dielectric material consists of a coaxial line on the inner conductor 1 attachable ring part 2 and three with this ring part consisting of one piece support arms 3, which on

ίο the circumference of the ring part are evenly distributed. When the support is installed, the ends of the support arms rest against the inner wall of the outer conductor 4 of the coaxial line.
Each support arm 3 is designed in the shape of a sector, namely the radially extending and the angle enclosing longitudinal edges 5, 6 each intersect in the center of the inner conductor 1, as shown in FIG. 1 is indicated by the dashed line extensions of the longitudinal edges 5, 6.

The arrangement and design of the ring part and the support arms attached to it results in that the electrical field developing between inner conductor 1 and outer conductor 4 of the coaxial line the edge 9 of the ring part only intersects perpendicularly or parallel to the longitudinal edges 5, 6 of the support runs.

For the wave resistance of the support according to the invention results regardless of the number of Support arms, the width of these arms and the distribution around the circumference of the ring part, use the following formula:

From the above formula, the other dimensions of the support can be calculated in a simple manner for each desired characteristic impedance value of a line, depending on the dielectric constant of the support material to be used and the existing or selected dimensions of the coaxial line. If, for example, as is often the case in practice, both the dielectric constant of the support material and the diameters d _z and d _{3 are} given and the outer diameter of the inner conductor d _{x is} sought, the following relationship results:

exp

e _r · In

In

2π

sr-ln -J-

«2

1 + (* r - 1) ■

Ίπ

ε _Γ · In

1 + («τ - 1)

Σ *

2π

In d ₃ · In d ₂

The new support can either 65 connection of the support arms 3 with the inner surface of the inner conductor

only attached or with the ring part 2 in an ent- outer conductor.

speaking trained annular groove of the inner conductor on the support according to the invention can in itself

be let in. The same applies to the known way an annular recess in front of

be seen through which the capacitive influence of the Front faces of the support is compensated. In the one shown in FIG. 1 is this annular Recess 7 is formed on the individual support arms 3 between the ring part 2 and the outer conductor 4. A particularly easy-to-manufacture arrangement is obtained for this if the one surrounding the inner conductor 1 Ring part 2 coincides with the inner edge section 8 of the annular recess 7.

Claims (1)

Claim: Dielectric support for inner conductors of coaxial systems, the wave resistance of which is in the range of Support by changing the inner conductor and / or outer conductor diameter accordingly adjacent pillarless coaxial sections is adapted, as well as with in the area between inner and outer conductor provided openings, characterized by the inner conductor (1) surrounding ring part (2) and two or more, preferably three, radially outward protruding, distributed approximately evenly on the ring part circumference and connected to this Support arms (3) of a circular sector-shaped outline, the longitudinal edges of which with radii of the ring part coincide and the ring part and the support arms are dimensioned according to the following formula: Z = 60 In (e _r - D + 1 - (er-l) + l In «2 y In In where Z is the wave resistance of the support, s _{r is} the relative dielectric constant of the support material, ^ j κ is the sum of the angular areas covered by the individual sector supports and d _{x is} the outer diameter of the inner conductor, d _{2 is} the outer diameter of the ring part and ^ _{3 is} the inner diameter of the outer conductor. Considered publications:
German patents No. 924 759, 917 615, British Patent Specification No. 584153,
011; AEÜ magazine, December 1949, vol. 3, no. 9, pp. 316 and 322. 1 sheet of drawings 509 540/340 4.65 © Bundesdruckerci Berlin