US2047531A - Arrangement for transmission of ultra short waves - Google Patents

Description

July 14, 1936. M. VON ARDENNE ARRANGEMENT FOR TRANSMISSION OF ULTRA, SHORT WAVES v Fild June 19, 1931 Patented July 14, 1936 UNITED STATES PATENT OFFICE ARRANGEMENT FOR TRANSMISSION OF ULTRA SHORT WAVES Application June 19, 1931, Serial No. 545,459 In Germany June 21, 1930 4 Claims.

The subject matter of the present invention is constituted by an arrangement for the transmission of a plurality of ultra-short waves, or one or more ultra-short wave bands. As well known, ultra-short waves permit only of transmission between places which are within visible range or practically within visible range of each other. For this reason it is necessary, for the transmission of ultra-short waves over relatively long distances, to provide intermediate arrangements, which are arranged in elevated position for the purpose of ensuring transmission to the next station, and are furnished with an intermediate receiver by which an intermediate transmitter is controlled. Since arrangements of this description are also essential in the transmission of one single ultra-short wavelength, a plant of this kind would not be sufficiently productive. This was a promoting factor which suggested this invention, and which, therefore, has the object of rendering the series of intermediate arrangements suitable for the transmission of a plurality I of ultra-short waves. For various reasons, and more particularly on account of secrecy of the messages, considerably less consumption of energy and a more favourable technical form, the receiver and transmitter are furnished with reflectors, which pick up the radiated waves, or transmit the waves respectively. For transmission over relatively long distances the intermediate arrangements above referred to would accordingly be furnished with a receiving reflector and a transmitting reflector, between which there is arranged the transmission device. Now it is not immediately possible to provide for this purpose an amplifying arrangement of any kind, as transmission of a plurality of substantially different ultra-short waves would in this manner naturally be impossible, and even the transmission of a narrow frequency band would be prevented by reason of the high selectivity produced by the large number of intermediate stations necessary for relatively long distances.

According now to the invention, there are employed for transmitting a frequency band, resonance amplifiers which are slightly relatively detuned, so that the effective resonance curve is provided with a sufficient width of frequency, and therefore amplification of the particular frequency band, or a plurality of ultra-short waves respectively, is thus rendered possible.

A such arrangement does not suffice for the transmission of a plurality of ultra-short waves which differ very appreciably from each other,

or for relatively wide frequency bands. For this reason according to this invention semi-aperiodic amplifiers are employed in instances of this kind,

i. e., amplifiers which possess poor-capacity chokesv in their anode circuit. According to the 5 present invention the transmission range of an intermediate chain of transmitters of this kind may be extended to a very wide frequency range by the use of wholly aperiodical amplifiers, the technical execution of which has more recently 10 been rendered possible by the use of amplifier structures of very poor capacity having highly emissive cathodes.

The intermediate receivers and intermediate d transmitters may, in accordance with the invention, be connected by a plurality of preferably parallel arrangements tuned to different frequencies, and the resonance frequencies distributed in suitable manner over the range to be transmitted. For this purpose, according to the 20 invention, there are provided a plurality of correspondingly-differently tuned dipoles in the re fiectors.

In the accompanying drawings Fig. 1 shows diagrammatically a repeating-station according to the invention with a receiver, a transmitter and the amplifier arranged between both.

Fig. 2 shows a complete arrangement with transmitter, receiver and amplifier.

l is a parabolic reflector, in the straight lines of focus of which are disposed the dipole wires 3 and 4. These wires are connected by leads 5 with a non-improved or even strongly attenuated oscillatory circuit 6, which, with the provision of a biasing potential battery 8, is located between the cathode and the control grid 9 of an amplifying tube 1. The cathode of this amplifying tube, in similar manner to that of the second tube I9, is heated by a heating battery. The anode I I leads over a highly resistive element 12 of, say, 2000 ohms to the positive battery pole of the anode potential source l3, which is joined by its other pole to the cathode of the tube. The oscillations of potential occurring at the anode I l are passed over a condenser It to the control grid 20 of the tube I9, this grid receiving the necessary negative bias potential from the grid battery l8 via a leakage resistance l1. Both tubes are preferably constructed as screening grid tubes, where- 50 by the screening grids, in a preferred form of embodiment, may be connected with each other, and, in relation to the cathode, receive a positive potential from the battery I l. The anode 22 of the second tube I9 is connected, via an oscillatory circuit 23, which is similar to the circuit 6, i. e., is not improved or may even be strongly attenuated, with the positive pole of the anode potential source l3. From the ends of the oscillatory circuit the leads 24 pass to the dipole wires 25 and 26, which are provided within the radiating parabolic reflector 2, preferably in the straight line of focus.

In the case of such intermediate arrangements it is absolutely essential to prevent a back-coupling from the intermediate transmitter to the intermediate receiver assigned thereto. This, according to the invention, may be accomplished by suitable construction and arrangement of the reflectors.

Since for the reasons above stated directional transmitters and receivers are employed, it is absolutely essential in transmission over relatively long distances that the stations are in permanent location. In the transmission over seas, lakes, etc. difiiculties are encountered in this connection. To ensure the necessary non-rocking position at sea, the intermediate arrangements are mounted in elevated fashion on large plates, which are carried by the long rods of supporting members, preferably hollow members. The supporting rods extend to such depth into the water that the movement of the latter, which takes place principally at the surface, has no influence on the position of the supporting plate, and accordingly that of the reflectors. These arrangements are anchored to the bed of the sea.

Fig. 2 illustrates the whole arrangement of the transmitting-system. The repeating device consists of the repeating receiver 39 and. the repeating transmitter 4| being coupled by means of an amplifier system 40, operating substantially aperiodically. The entire repeating device 39, 40, 4| is arranged at a suitable place between the transmitter 38 and the receiver 42. For bridging greater distances, several repeating devices of a suitable number and with a suitable directional effect may be arranged at suitable places between transmitter 38 and receiver 42. Several amplifier arrangements being dimensioned for the amplification of different frequency-bands or being tuned to difierent frequencies, may be employed in parallel for the connection between repeating receiver 39 and repeating transmitter ll, instead of one single amplifier-arrangement 40.

I claim:

1. In a system for transmitting ultra-short waves over long distances by means of repeating stations, a repeating station comprising a unidirectional receiving antenna, a similar retransmitting antenna radiating in a practically opposite direction and amplifiers connecting said antennas directly, said amplifiers being deturned relatively to each other.

2. In a system for transmitting ultra-short waves over long distances by means of repeating stations, a repeating station comprising a unidirectional receiving antenna, a similar retransmitting antenna radiating in a practically opposite direction and amplifiers connecting said antennas directly, said amplifiers being broadly tuned.

3. In a system for transmitting ultra-short waves over long distances by means of repeating stations, a repeating station comprising a unidirectional receiving antenna, a similar retransmittlng antenna radiating in a practically opposite direction and amplifiers connecting said antennas directly, said amplifiers being detuned relatively to each other, said amplifiers being coupled aperiodically.

4. In a system for transmitting ultra-short Waves over long distances by means of repeating stations, a repeating station comprising a unidirectional receiving antenna, a similar retransmitting antenna radiating in a practically opposite direction and amplifiers connecting said antennas directly, said amplifiers being broadly tuned, said amplifiers being coupled aperiodically.

MANFRED VON ARDENNE.

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