US2297513A - Transmission line - Google Patents

Description

J. R. VON BAEYER TRANSMISSI-ON LINE Filed Oct. 1-8, 1940 INVENTOR f/ans Jacob lfifl'er V0056! P w e H N Z K A 7 Y B nected unilaterally thereto.

Patented Sept. 29, 1942 UNITED STATES PATENT OFFICE TRANSMISSION LINE Hans Jakob Ritter von Baeyer, Berlin, Germany; vested in the Alien Property Custodian Application October 18, 1940, Serial No. 361,698 In Germany May 20, 1939 4 Claims.

stated, these cups must be tuned in their length whereby lengths are obtained equal to a quarter wavelength, or when employing additional reactances, equal to slightly less than a quarter wave. For long wavelengths this measure necessitates considerable dimensions and thus a substantially larger amount of means of the structure. In order to reduce this structural tain within reasonable limits the dimensions of the blocking cup in the case of longer waves, it is proposed in "accordance with the present invention, to divide the cup into two or a larger number of tubes inserted into each other from opposite sides and connected respectively with the covering of the line in a unilateral manner. The lengths of said tubes are so chosen that a line is formed which extends to and fro in a requirement and to mainshown in Figure 2' the cup is divided up into three reciprocating paths which in total are to be tuned to x/4.

Finally, Figure 3 shows a cup subdivided six times in its application to the feeding of an antenna from a shielded cable. The current on the cable covering is absorbed by the tuned rods St and the residual excitation of the cable cover is completely suppressed by the cup. More especially in the case of a large number of divisions of the cup as shown in Figure 3, care must be taken (which is, however, not shown especially in the drawing) inchoosing the individual diameters of the various tubes in such a manner whereby the wave resistances of the individual conductors coaxially arranged around said first mentioned conductor, alternate ones of said tubular conductors being connected at one end to said first named conductor and the remaining ones at multiple fashion and is short-circuited at the end thereof whereby the input impedance of the line has the required value.

Figure 1 shows a first example of construction according to the present invention, while Figures 2 and 3 show modificationsthereof. In Figure 1 a V4 radiator A is fed from a shielded line K. The upper end of the covering C of the line K having the length equal to A/4 oscillates freely and completes in this manner the radiator to a dipole. In the current node (the current distribution on the radiator and line cover is shown in broken lines) a blocking cup T is arranged whose geometrical length is relatively short as compared with the wavelength on account of the placing into each other of. several conductors according to the present invention. Yet the open input of the cup respresents a very high resistance (resonance resistance) if the path extending to and fro in the interior ofthe cup is tuned to M4.

Figure 2 shows the transit of a symmetrical double line D into a shielded line K through the use of a symmetry establishing cup T adapted according to the present invention. The connection V can in general be omitted and thus it is shown in broken lines. In the adaptation the other end whereby an elongated chamber folded concentrically with respect to said first named conductor and closed at its inner end is formed, the length of said chamber being such as to present a high impedance at its outer end to said high frequency energy, and means presenting a low impedance path to ground for said energy connected to the outer of said tubular at the other end whereby an elongated chamber folded concentrically with respect to said first named conductor and closed at its inner end is formed, the electrical length of.said chamber being an odd multiple, including unity, of one quarter of the operating wavelength, and means presenting a low impedance path to ground for said energy connected to the outer of said tubular conductors.

3. An arrangement for suppressing transmission of high frequency energy along the outer shell of a concentric transmission line comprising a plurality of tubular conductors coaxially arranged about said shell, alternate ones of said tubular conductors being connected at one end to said shell and the remaining ones to said shell at the other end whereby an elongated chamber folded concentrically with respect to the axis of said shell and closed at its inner end is formed the length of said chamber being such as to present a high impedance at its outer end to said high frequency energy, and tuned absorption rods connected to the outer of said tubular .conductors.

4. An arrangement for suppressing transmission of high frequency energy along the outer shell of a concentric transmission line comprising a plurality oi. tubular conductors coaxially arranged about said shell, alternate ones of said tubular conductors being connected at one end to said shell and the remaining ones to said shell at the other end whereby an elongated chamber folded concentrically with respect to the axis of said shell and closed at its inner end is formed, the electrical length of said chamber being an odd multiple, including unity, of one quarter of the operating wavelength, and tuned absorption rods connected to the outer 01' said tubular conductors.

HANS JAKOB RIITER vorz BAEYER.

Images