US2031101A - Arrangement adapted to generate ultra short electromagnetic waves - Google Patents

Description

Feb, H936.

ARRANGEMENT E. FETTEROWSKY ET AL. ZEELEH ADAPTED 'I 0 GENERATE ULTRA SHORT ELECTROMAGNETIC WAVES Filed July 1, 1933 MODULAWA/G DEV/C6 Patented Feb. 18, 1936 UNITED STATES PATENT OFFICE ARRANGEMENT ADAPTED TO GENER- ATE ULTRA SHORT ELECTROMAGNETIC WAVES Application July 1, 1933, Serial No. 678,570 In Germany July 13, 1932 2 Claims.

For the generation of extra short electroma netic waves, recourse may be had, as known from the earlier art, to the socalled Barkhausen-Kurz circuit which has this distinguishing feature, that 5 the control grid in a tube with three or more electrodes is supplied with a high positive voltage and the plate with a negative voltage. The present invention discloses a circuit scheme in which the outer plate potential source may be dispensed with.

The plate current in a Barkhausen-Kurz circuit arrangement containing an oscillating tube is due to that part of the electrons which are emitted from the cathode and accelerated by the positive grid potential and fly against and strike the negatively biased plate. The sense of the current thus is such that the current flows into the plate battery and tends to charge the same. The incidental consumption of energy is covered by the grid battery. Now, according to the invention, the negative potential required at the plate could be produced simply by connecting the latter with the cathode by way of a suitably chosen resistance R as illustrated in Figure 1. The sense of the plate current is such that the end of the resistance united with the plate, in ref erence to the filament, is of negative potential.

Figures 1 and 2 illustrate two difierent embodiments of the invention.

Referring to Figure 1, for the adjustment of the proper potential, the said resistance R is preferably made adjustable. The resistance acts at the same time also as a radio frequency choke and it prevents or impedes the drain of oscillations into the battery wires. However, if a distinct choke coil Dr is to be used, then it is advisable to arrange a condenser C in parallel relation to the resistance R to act as an energy accumulator.

As shown in Figure 2, the variable resistance could consist also of the filament plate path of a triode M in which case variation of resistance is insured by variation of the grid biasing voltage Eg. The same arrangement, unaltered, could be employed also for the modulation of the radio frequency oscillation by audio frequency impulses which are fed to the grid of the input tube M, say, by way of a transformer T. The use of an input tube in the plate D. C. circuit for modulation of the oscillations as known in the prior art could in the present case be developed in that the tube serves at the same time for the production of the negative plate potential.

What is claimed is:

1. An ultra short wave circuit comprising an electron discharge device having anode, cathode and control electrodes, a source of potential in circuit with said cathode and control electrode for applying to said control electrode a high positive potential with respect to cathode, and means excluding the use of a separate source of anode potential for causing said anode mice at a negative potential with respect to said cathode, said last means comprising an efiective resistance connected between said anode and cathode which is arranged to be traversed by the current in said anode circuit.

2. A system in accordance with claim 1 including a condenser in shunt with said efiective resistance and a choke coil serially arranged in circuit with said resistance between said anode and cathode.

EDUARD FETTEROWSKY. HEINZ LUX.

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