DE397869C - Radio frequency system for transmitting messages - Google Patents

Description

GERMAN EMPIRE

ISSUED JULY 2, 1924

REICHSPATENTAMT '

PATENT LETTERING

CLASS 21 a GROUP 69

Bell Telephone Manufacturing Company, Societe Anonyme in Antwerp.

Radio frequency system for conveying messages.

Patented in the German Empire on February 20, 1920.

According to the Union Treaty of June 2, xgii, the priority for this registration is due the application ia the United States of America dated March 3, 1916 claimed.

In wireless signaling: in practice, however, the number of waves that can be sent using high frequency waves through which it is possible is thereby several at the same time; expected occurrence of interference on signals to send that several simultaneously; Receiver limits unless the Fre-high frequency waves emitted and \ quenzunterschied between the various special circuits that j to the individual waves is quite large. Bodies are matched, are received. . The present invention

allows a single emitted wave to carry multiple independent signals can, if one uses several such shafts; thereby the total number of Signals that can be transmitted without interference can be enlarged. this will according to the invention achieved in that, for example, a wave whose frequency is a Million is influenced by another ίο wave whose frequency is lower, but above "the limit of audibility and is constant, for example 50,000 Periods per second, and that this second wave in turn in the rhythm of one to transmitted character is influenced. At the same time, the transmitted wave can with the frequency of a million are affected by several other such second waves, for example by waves with the Freao sequences 40,000, 30,000, 20,000, each of these waves again in a special one Character rhythm is influenced. In the particular case mentioned above, 4 signals can therefore be transmitted by means of the same transmitter wave can be transmitted at the constant frequency of one million. When using several other not disturbing each other Transmission shafts, e.g. B. of 3 more, so a total of 4 not interfering with each other Transmitter waves, 16 independent signals can be sent instead of! of only 4 in the event that the second modulation waves were not used. !

The essence of the invention is evident from the description below, in conjunction with the enclosed drawing, to see clearly. The drawing shows: Fig. 1 a transmitter station, Fig. 2 a receiving station according to the invention. ;

In Fig. Ι 1 represents a generator for high frequency waves that generates a million changes per second, for example. 2 is one excited by the generator 1 and connected to the j input terminals of a thermionic supply! stronger connected circuit. 3 is a j generator of waves of lower frequency, for example 40,000 periods per second, while with 3 ', 3 "etc. other generators are labeled with different high frequencies, all of which are lower than that of the Generator 1. With 4 a thermionic amplifier is referred to, the input circuit with the circuit of the generator 3 i and also with the circuit 5, which a; Microphone or other primary source of j low frequency signal streams, ver j is bound. In the same way, 5 'and 5 "represent other independent sources of simultaneously to be transmitted signals. The output circuit of the amplifier 4 is tuned to the frequency generated by the bite Circuit 6 connected, which in turn is coupled to circuit 2. As a result of this arrangement appear in the rhythm of the characters Currents influenced by the frequency generated at 3 in circuit 6 and are applied to those appearing in circuit 2 Currents superposed. It will therefore be on the input circuit amplifier 7 first Waves of a frequency generated at 1 are imposed, and secondly a series of Waves with frequencies determined by 3,3 'etc., the latter being waves can be influenced in the rhythm of the various signal frequencies. As a result, appears in the output circuit of the amplifier 7 and in the circuit 8 tuned to the highest frequency a high, frequency wave, which in the rhythm of a series of in turn controlled high frequency waves is affected. The amplifiers 9 are arranged in such a way that they influenced the intensity of these Multiply the wave and press it onto the transmitting antennas 10.

In Fig. 2, 12 represents a receiving antenna represents, which is coupled to the circuit 13, which is based on the by the generator 1 of Fig. Ι generated frequency is tuned. With a detector 14 is designated, the input circuit is connected to the tuned oscillation circuit 13 and a current occurs in its output circuit, whose amplitude curve is the envelope curve! of the transmitted high frequency wave. The circuit 15 is matched to the frequency of the generator 3 in Fig. 1, 15 ' on the frequency of the generator 3 'etc. The one in the circuit tuned to 15 16 occurring current therefore has almost exclusively the frequency of voo in generator 3 generated high-frequency current. The apparatus 17, whose input circuit with the matched circuit 16 is connected, serves as a detector for the incoming signals, whereby an audible signal is generated in telephone 18. Similar detector circuits (not shown in the drawing) are connected to the matched circuit 16 ', 16 ", etc.

It can be seen that as a result of this an-order 4 independent signals can be transmitted on only a single high frequency wave. Of simplicity for the sake of the drawing is only a high-frequency generator, for example, waves with a million periods per second has been shown. However, it is without further clear that other frequencies can be used to increase the number of to multiply the signals to be transmitted. iao

Understandably, the essential feature of this method is that the dea

Generators 3, 3 'etc. generated frequencies are above the limit of audibility, and that the frequency difference between successive waves is large enough to prevent interference. It will be readily understood that this invention in no way applies to wireless communications is limited, but also applies to high-frequency communications can be used along a line. The invention can of course also be used in a system in which different stations simultaneously generate the same high frequency, but with these waves through various intermediate waves can be controlled. In this case, between caused no interference with the waves of the individual stations.

Claims (8)

Patent Claims: 1. High-frequency multiple or secret transmission of messages, thereby characterized in that a high frequency wave (fundamental wave) is initially im The rhythm of a number of other waves is controlled, the frequency of which is above the auditory frequency, but lower than the frequency of the fundamental wave, whereupon these different waves each individually in the rhythm of an even lower frequency (Signal frequency) can be controlled. 2. Transmission arrangement according to claim 1, characterized in that the intermediate frequency generating and controlling circuit and the high frequency carrier wave generating and controlling circuit One source each of undamped oscillations and one modulator for the thermionic ones Amplifier type contains, on which the relevant undamped wave at the same time .with the modulating wave is pressed. 3. Transmission arrangement according to claim 1, wherein a high-frequency carrier wave generating and modulating circuit and a number of intermediate frequency generating and modulating circuits are provided according to claim 2, characterized in that the output sides of the thermionic modulators for the intermediate frequency waves are commonly connected to the high frequency modulator.
4. Transmission arrangement according to claim 1 and 3, characterized in that the Output circuits of the various modulators for the intermediate frequency waves have filter circuits to have a reaction between those generating and modulating the various intermediate frequency waves To prevent circles, the filter circuits are connected together with the circuit of the high-frequency modulator are. 5. Receiving arrangement according to claim 1, 6g in which a high frequency carrier wave and one of speech or the like Wave-controlled, inaudible intermediate frequency is used, characterized in that that a first detector circuit is provided to detect the variations of the high frequency carrier wave and a second detector circuit for the derivation of the speech variations of the intermediate frequency wave, wherein the radio frequency receiving center, the first detector circuit, the second detector circuit and a receiver, which sensitive to the variations in the characteristic of the intermediate frequency wave, successively connected are. 6. Receiving arrangement for multiple signaling, characterized by a first detector circuit and a number of second such circuits, each circuit consisting of a tube detector with input and There is output circuits and the input circuits of the second detectors together with the output circuit of the first Detector are connected. 7. receiving arrangement according to claim 1 and 6, characterized in that filter circuits between the first and the various second detector circuits are switched on, these filter circuits on the intermediate frequencies act selectively. 8. Signal system according to claim 1, characterized in that the receiving circuits a number of high frequency waves are imposed, at least one of which to the rhythm of the speech or is modulated by other signals and wherein the receiving circuit has a first Detector circuit has one or more waves modulated by the signals from the impressed waves lower frequency than the 'imprinted To derive waves, and one or more second detector circuits to respond to the waves emitted by the first detector to act and to make the signals recognizable. 1 sheet of drawings.