US1943627A

US1943627A - High frequency oscillator

Info

Publication number: US1943627A
Application number: US453449A
Authority: US
Inventors: Rothe Horst; Roosenstein Hans Otto
Original assignee: Telefunken AG
Current assignee: Telefunken AG
Priority date: 1929-06-01
Filing date: 1930-05-19
Publication date: 1934-01-16
Anticipated expiration: 1951-01-16
Also published as: NL29470C

Description

Jan. 16, 1934. H. ROTHE El AL 1,943,627

HIGH FREQUENCY OSCILLATOR Filed May 19. 1930 gzzzm FE! l. g A 4) T J IL INVENTORS HORST ROTHE BY HANS OTTO ROOSENSTEIN ATTORNEY Patented Jan. 16, 1934:

1,943,627 HIGH FREQUENCY OSCILLATOR Horst Rothe 4 Claims.

It has been found that .in the case of oscillator circuits for extremely high frequencies it is very diificult in practice to preclude radio frequency waves from the D. C. leads brought to the apparatus. In order to obviate this difiiculty the leads carrying plate and grid currents are suitably brought to a point in the oscillation circuit whose radio frequency potential to ground is as low as possible. In order that at the same point the plate and the grid currents may be connected, one way out would be to insert in the circuit such a large blocking condenser Cb (Fig. 1) that the flow or" radio frequency will practically not be influenced. However, especially where very high frequencies are dealt with it is practically impossible in this scheme to pre-determine the point where the circuit is to be cut in such a manner that owing to the existent division of potential by way of Cgk and Ca}; the internal capacities of the tubes will present a minimum potential in the circuit. Once the cut or separation has been established, a change in location, i. e., a shift in tapping points for supplying D. C. potentials is but difiicultly accomplishable.

In the accompanying drawing Figure 1 is given by way of explanation of the present invention described in detail in connection with Figure 2.

Now, according to this invention the inconvenience already indicated, is obviated by that the oscillation circuit throughout its entire length is made to consist of two conductors 2, 4 (Fig. 2) presenting such a capacity in relation to each other that the entire system, looked at from a viewpoint of radio frequency, may be conceived as a single conductor. One suitable embodiment consists in that the oscillating loop is built up of two or more copper bands or strips being separated from one another by interposed layers of mica, for instance. Along these bands the taps 6, 8 for grid and plate current are effected by the aid of a double slide adjustable in the course of operations.

The arrangement here disclosed offers this further merit that the two filament leads 10 conjointly with the grid and the plate D. C. leads may be wound upon a choke-coil 14. The beginning of the latter is connected by way of four blocking condensers K K to the shielding box 16 or cage of the set. This mode of grounding can be established again at another point of the choke-coil (K -K Fig. 2). It is recommendable to so choose this second point that the two parts will exhibit practically no joint overtones. If proper care is taken in this respect it will be and Hans Berlin, Germany, assignors to Telefunken Gesellschait fur Drahtlose Telegraphic m. b. EL, Berlin, Germany, a corporation of Germany Application May 19, 1930, Serial No. 453,449,

- and in Germany June 1, 1929 Gtto Roosenstein,

possible to establish and provide perfect screening or shielding of the set which is otherwise but hard to insure in the case of ultra-short waves.

We claim as our invention:

1. A high frequency oscillatory circuit having, in combination, an electron discharge device comprising an anode and a grid, an oscillatory circuit comprising two open ended, closely adjacent conductors, one of said conductors being connected with the grid, and the other of said conductors with the anode, the open end of the conductor connected to the anode being near the connection point of the other open ended conductor to the grid, and the open end of the conductor connected to the grid being near the end of the open ended conductor connected to the anode, said two conductors presenting such a high distributed capacity in relation to each other that they can be regarded as a single conductor from a radio frequency standpoint, a source of grid potential and a source of anode potential, and leads extending from said sources to the open ended conductors connecting with said grid and anode, said leads being adjustable with resoect to the ends of said conductors.

2. A high frequency oscillatory circuit having, in combination, an electron discharge device comprising an anode, cathode and a grid, an oscillatory circuit comprising two open ended, closely adjacent conductors, one of said conductors be- 85 ing connected to said grid, and the other one of said conductors being connected to said anode, the open end of the conductor connected to said anode being near the connection point of the other open ended conductor to the grid, and the open end of the conductor connected to the grid being near the end of the open ended conductor connected to the anode, a source of grid potential, a source of anode potential, and a source of cathode potential, leads extending from said sources of grid and anode potential to theconductors connecting with said grid and anode, and leads extending from said cathode to said source of cathode potential, a choke coil, said supply leads for said cathode, anode and grid being wrapped upon said one choke coil and said choke coil being grounded by way of condensers.

3. An oscillator having an anode a cathode and a control electrode, an open-ended conductor connected to said control electrode, an open-ended conductor connected to said anode, said conductors lying adjacent each other and relatively parallel to each other, the open end of the conductor connected to said control electrode being adjacent the connection point of the open-ended 110 conductor connected to the anode, the open end of the conductor connected to said anode being adjacent the connection point of said open-ended conductor connected to said control electrode, a source of anode potential, a source of control electrode potential, and adjustable means for coupling said sources through said open-ended conductors to said anode and control electrode at points intermediate the ends of said conductors, and individual condensers for said anode and control electrodes, the armatures on one side of said condensers being connected to said adjustable coupling means and the armatures on the other side of said condensers being in circuit with said cathode.

4. Apparatus having, in combination, an electron discharge device comprising an anode, cathode and control electrode, an open-ended conductor connected to said control electrode, an open-ended conductor connected to said anode, said conductors lying adjacent to each other and all relatively parallel to each other, the open end of the conductor connected to said control electrode being adjacent to the connection point of the open-ended conductor connected to the anode, the open end of the conductor connected to said anode being adjacent the connection point of said open-ended conductor connected to said control electrode, a source of anode potential, a source of control electrode potential, individual connections between said anode and control electrode sources of potential and points on said conductors intermediate their ends, said connections being adjustable on said conductors, a source of cathode potential connected to both legs of said cathode, individual condensers arranged between said adjustable connections and ground, and additional condensers between both legs of said cathode and ground.

HORST ROTHE. HANS OTTO ROOSENSTEIN.