US1745389A - Frequency multiplier - Google Patents

Description

Patented Feb. 4, 1930 y UNITED STATES PATENT OFFICE GEORG Von ARGO, OF BERLIN, GERMAN Y, ASSIGNOB- TO GESELLSCHAFT FU'R DRAHTLOSE TELEGRAPHIE M. B. H.,

OF BERLIN, GERMANY FREQUENGY MULTIPLIER In the known methods for increasing the frequency of any fundamental period by means of static transformers a large number of frequency transformers connected in cascade was used, each step of thearrangement only doubling or tripling the frequency. This method has, however, a poor efficiency because every step of the cascade causes a loss of energy. This loss increases nearly in proportion to the frequency which, of course, rises in geometrical progression.

This method had, therefore, low efficiency and thearrangementwas complicated and expensive. Accordingly this method was replaced by that of increasing the frequency by means of a single transformer. By this methodit was possible to attain ratios of transformation as high as 1:27. In using one single transformer a very simple arrangement was obtained, but an analysis of the radiated oscillation showed that this oscillation contained very many adjacent harmonics. These harmonics of a transmitting station greatly disturb those neighboring receiving stations which are tuned to a wavelength which is by chance in accordance with one of these harmonics.

The present invention relates to an arrangement for frequently increase by which a final frequency is generated which contains only very few disturbing harmonics.

' According to the invention the frequency increase, particularly that of a high multiple of the fundamental frequency is always car ried out by means of two transformers, the first fitted up for a great frequency increase and the second only for a small frequency increase, for instance doubling or tripling the input frequency.

It is attained by reason that the disturbing harmonics according to the invention greatly differ from the radiated desired final oscillation in spite of a very high transformation. By means of traps and filters, well known in the art these greatly differing harmonics can easily be eliminated.

The single figure shows diagrammatically an embodiment of my inven lgn.

In said figure, the high frequency generator is shown coupled to the first frequency 731,225, and in Germany August 17, 1928.

changer circuit which in turn leads to the second frequency changer and then to'the utilizing circuit.

An example will serve to explain this invention. Assume the fundamental frequency to be 10,000 and it is desired to increase it 27 times. The first transformation will then increase the fundamental frequency 9 times, that is, to 90,000 and the second transformation increases this frequency 3 times, that is, to 270,000. Thus the useful frequency is 270,000 while the next disturbing waves have the frequencies 450,000 and 90,000, assuming thatthe frequency multipliers used generate only odd harmonics. Many of the well known frequency changers can be made to generateonly odd harmonics. These harmonics greatly differing from the useful frequency have but small energy and can if necessary be easily eliminated by means of any well known filtering circuits, as pointed out above.

The above described arrangement is specially simplified if, as'in the above example, the second transformation increases the frequency 3 times and if the first transformation is so chosen that it increases the fundamental frequency by an odd but greater multiple. In this case the direct current magnetization absolutely necessary for the even multiples can be left out and an extraordinarily simple and good arrangement is obtained.

Having described my invention, I claim :J

1. In a high frequency multiplication system of the character described for changing a fundamental frequency into a higher frequency comprising in combination an iron cored frequency multiplication transformer having its input circuit fed by current of said fundamental frequency, a second. frequency multiplication transformer connected in cascade with said first frequency transformer and having a multiplication ratio relativel small with respect to that of the first frequency transformer.

2. In a high frequency multiplication system of the character described for changing a fundamental frequency into another higher cored frequenc transformer having its input circuit fe by said fundamental frequency, a second frequency transformer having a multiplication ratio relatively small with respect to that of the first frequency transformer and means for coupling the output circuit ofthe first transformer with said input circuit of said second transformer.

3. A device for greatly increasing the frequency of oscillation in an electrical system by means of static transformers which com prises a pair of static transformers, the second thereof bein ada ted to increase the outgut frequency 0 the rst three times and the rst thereof being adapted to increase the fundamental frequency by an odd but greater multiple, whereby it is unnecessary to magnetize the. cores of the transformers by direct current.

4. A device for quency of electrical oscillations by means of static transformers whichcomp'rises means including a first static transformer adapted to increase the fundamental frequency by an odd multiple and a second static transformer adapted to increase the frequency produced by said first static transformer. by a multiple less than the said multiple increase in said first transformation.

' 5; A. device for greatly increasing the frequency of electrical oscillations .by means of 7 static transformers which comprises means including .a first static transformer adapted to increase the fundamental frequency nine times and a second statictransformer ada ted to increase the frequency produced by said first static transformer three times.

GEORG VON ARGO.

greatly increasing the fre-

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