DE1043431B - Balancing arrangement for the transition from an asymmetrical strip line, in particular a microstrip line, to a symmetrical line, in particular a strip line - Google Patents

Description

GERMAN

The invention relates to a balancing arrangement such as that used in particular for microwaves Can be found. The arrangement is used to transition an asymmetrical ribbon line, in particular Microstrip line, on a symmetrical line, especially a ribbon line.

In the case of an asymmetrical ribbon line for microwaves, a planar, flat line is preferably used Conductor used as a so-called "earth conductor" to which a so-called "line conductor" is arranged in parallel is, namely at a certain distance, which is formed by a layer of dielectric material will. The two conductors forming the ribbon cable must be of different widths. The preferably At least three times wider earth conductor then acts electrically approximately like an infinitely extended one senior level. The field distribution corresponds roughly to that between one conductor and the neutral plane of a parallel ladder system. Such a line is called a »microstrip line« ao designated.

The known balancing arrangements, which are mostly based on the so-called EMI loop or based on the 2/2-detour line are in coaxial design for the microstrip technology because of their Undefined four-pole connection only partially usable. In addition, such arrangements as a result their large spatial structure already from 1 GHz. with crowded antenna fields Bring strong field coupling with it, so that in many cases difficulties arise in the adaptation over a wide frequency range.

The use of shorter and shorter wavelengths has now led to the fact that for the components of the Microwave technology special manufacturing processes were developed. So one uses z. B. printed Antennas and microstrips, d. This means that the microstrip technology, which is particularly suitable for this wave range, is used Use.

So balancing arrangements have already become known that are made according to this new manufacturing technique are executed. In Funk and Ton, No. 9, 1954, p. 496, there is a transition from a symmetrical one Ribbon line shown on a coaxial cable. The balancing takes place with the help of a 1/2 detour line, which is carried out here in microstrip technology. This implementation is with regard to the balancing only applicable in a narrow frequency range.

In the Symposium on Microwave Circuits, Vol. MTT - 3, March 1955, No. 2, p. 153, a Balancing arrangement shown, which is an unbalanced strip line (microstrip) with the help of a Hybrid ring in a symmetrical ribbon cable over-balancing arrangement for the transition from an asymmetrical ribbon cable, in particular a microstrip cable, on a symmetrical line,

especially band line

Applicant:

Telefunken G.m.b.H., Berlin NW 87, Sickingenstr. 71

Dipl.-Ing. Horst speed

and Dipl.-Ing. Wolfgang Krank, Backnang (Württ.), Have been named as inventors

leads. The hybrid ring has a circumference of 3/2 λ, which means that its use is limited to relatively high frequencies due to its large spatial expansion. In addition, this embodiment is also very narrow-band with regard to balancing.

The invention relates to a balancing arrangement which is used for the transition from an unbalanced ribbon line, in particular a microstrip line, on a symmetrical line, in particular a ribbon cable, serves. Here, in a manner known per se, there is a balancing pot in the balancing point of the arrangement connected, designed according to the invention as a U-shaped bracket and on the one conductor of the asymmetrical Line is placed in parallel. This head of the unbalanced line goes over here into one conductor of the balanced line. The balancing pot is due to capacitive loading adjustable.

The invention will be explained in more detail below using an exemplary embodiment.

Fig. 1 shows a section through a balancing arrangement according to the invention. M denotes an electrically asymmetrical ribbon line, which is designed as a microstrip line, with the one conductor 2 lying at ground potential and the second conductor 1, which runs parallel thereto. These two conductors are separated from one another by a dielectric 3. The conductor 2 of the microstrip goes over

809 678/242

Claims (9)

3 4 in the conductor 5 of the symmetrical ribbon cable B. a waveguide line with the help of known, reflection-This ribbon cable also consists of two conductors 4 poor transitions are connected,
and 5, which are again isolated from one another by a dielectric 6, and the Tatanders are also often very advantageous. The balancing pot S consists in the fact that at point P or Q the continuation of the embodiment of a U-shaped bent, 5 symmetrical ribbon line B through corresponding self-supporting sheet metal strips. This the Symmetrier- choice of the strip width of the conductor 4 or 5 to each pot-forming U-shaped bracket has a certain arbitrary symmetrical line connected height /; and a longitudinal extension can become parallel to the un-. symmetrical ribbon line M of approximately a quarter wavelength. The symmetry is capacitively loaded by a metal sheet 7 through the U-shaped bracket of the symmetrizing pot. This sheet runs pot formed cavity H completely or partially parallel to the conductor 2 within the U-shaped bracket, fill with a solid dielectric. Thus, starting from the symmetry point P of the arrangement. there is the further advantageous possibility of making the by appropriately dimensioning the width of the U-shaped bracket from a thin metal foil and its immersion depth / in the cavity H 15 and applying it to the dielectric, for example by using the resonance wavelength of the symmetry Adhere. In this case the pot S needs to be set. The U-shaped bracket of the symmetrical bracket is no longer to be formed from a stable, self- treading pot at O with the conductor 2 of the unsymmetrical sheet metal, since the dielectric strip line (microstrip) is soldered. The lank ensures the stability of the arrangement. The ter2 has a recess at A through which the 20 overall length of the balancing pot is passed through the conductor 1 with little reflection and in the case of it is significantly shortened due to the shortening of the balancing point P both with the other end of the electrical length corresponding to] / i " with the head 4 of the revealed showed this balun arrangement via symmetrical strip line B galvanically connected to a large frequency range very low Fehlanist, for example by soldering. the dielectric 3 25 passungswerte. is still a little bit beyond window A , of course the conductive covering of the U-shaped In order to achieve better concentration of the field, bracket 6 "is also sprayed onto the dielectric or range (lower radiation losses) and the surface can be applied by galvanic etching processes. Order to achieve greater mechanical stability. It is particularly useful when using Rent. 30 metal foils, the conductive coating of the symmetry Fig. 2 shows a side view of the arrangement from point Q via O to P in one. The names of the parts are the same pieces cut out of a film, which is in series as in FIG production a significant shortening of the production is much narrower than the conductor 2 of the asymmetrical time and thus a considerable reduction in price results, Irish ribbon cable (about a third). 35 The application of the microstrip technique for this Fig. 3 is another side view. The width of the balancing arrangement also enables an additional U-shaped bracket corresponds to the width of the window. sters A. bring a second unbalanced ribbon line The U-shaped locking pot is opposite the micro- corresponding width and length on the outside strip line largely decoupled due to the U-shaped bracket of the balancing pot, starting out Skin effect, since the conductor 2 has a strip thickness from the symmetry point P over 6 ". sits, which is much greater than the depth of penetration A balancing arrangement according to the invention of the field at the short wavelengths used. The dielectric between the conductors 1 and 2 or stanchions is significantly cheaper than the previously common coaxial designs. The simple and compact 4 and 5 of the lines M and P practically results in the 45 compact structure, allowing them to be free from radiation up to the highest frequencies comparable to that of an all-round device. Furthermore, their volume is only about a double-shielded system. Both the asymmetrical band zigth of that of a coaxially constructed symmetrical line and the symmetrical band line are trier arrangement, and their weight is approximately eight times dimensioned in the exemplary embodiment so that they are smaller, and as a result an arrangement according to both has the same characteristic impedance. Considerably cheaper by 50 of the invention. In addition, there is corresponding dimensioning of the asymmetrical, the extremely simple production method and the ribbon line associated therewith can of course save costs associated with the balancing. at the same time a transformation of the wave counter- The invention is to be achieved on the drawn state of execution. form by no means restricted. The embodiment This extremely simple and very useful 55 only serves to explain the basic idea The form of the symmetry arrangement fits in with the organic invention, which varies in manifold ways niche in the cable run. The invention can be.
Execution allows installation in any guided Cable runs, be it in a straight, straight patent claim
Line run, as shown in the exemplary embodiment represents, or in a cable run, the example 1. Balancing arrangement for the transition from curved or angled. an unbalanced ribbon line, in particular If special circumstances require it, the microstrip line can be on a symmetrical leiganze Balancing arrangement also in a protective device, in particular a ribbon cable, thereby identifying container are housed, with a protective varnish 65 that draws in the symmetry point in known Coated or cast in a dielectric, a balancing pot is connected which the. In this way, the arrangement is carried out in front of atmo- as a U-shaped bracket and on the protected from spherical influences. one conductor of the unbalanced line, which is in The asymmetrical ribbon cable M can continue to use one conductor of the symmetrical line. so-rohl goes to a coaxial cable run as well as to 70, is placed in parallel, with the symmetry can be calibrated by capacitive loading. 2. Arrangement according to claim 1, characterized in that the capacitive load through a sheet is effected, which is preferably attached in the symmetry point and its Areas parallel to a conductor of the unbalanced line within the U-shaped bracket of the balancing pot runs. 3. Arrangement according to claim 1 and 2, characterized in that the U-shaped bracket entirely or partially filled with a solid dielectric. 4. Arrangement according to claim 3, characterized in that the balun completely with a solid dielectric is filled and the conductive bracket is made of a thin metal foil consists. 5. Arrangement according to claim 3, characterized in that both the conductive coating of the U-shaped bracket of the balancing pot and the opposite part of a conductor of the unbalanced Line and also the one conductor of the symmetrical line are cut out as a coherent unit from a metal foil. 6. Arrangement according to claim 4, characterized in that the conductive coating of the U-shaped Bracket in the form of a metal foil is glued to the dielectric. 7. Arrangement according to claim 4, characterized in that the conductive coating on the dielectric sprayed on or applied by special etching processes. 8. Arrangement according to one of the preceding claims, characterized in that on the Outside of the U-shaped bracket by attaching a second asymmetrical ribbon cable, in particular microstrip line, corresponding width and length, starting from the symmetry point, a series compensation is achieved. 9. Arrangement according to one of the preceding claims, characterized in that the Balancing arrangement housed in a protective container or cast in a dielectric is. 1 sheet of drawings ® «09 6781/242 11.58