US2238287A

US2238287A - Ultra short wave amplifier

Info

Publication number: US2238287A
Application number: US268719A
Authority: US
Inventors: Rahn Ernst
Original assignee: Telefunken AG
Current assignee: Telefunken AG
Priority date: 1938-05-13
Filing date: 1939-04-19
Publication date: 1941-04-15
Anticipated expiration: 1958-04-15

Description

April 15, 1941. E. RAHN ULTRA SHORT WAVE AMPLIFIER Filed April 19, 1959 5 OUR@ E VAA .Jin

INVEN TOR. ERA/$7' QHN ATTORNEY.

Patented Apr. l5,` 1941 ULTRA snoR'r WAVE `AivfrnIFlEn Ernst Rahn, Berlin, Germany, assignor to Telefunken Gesellschaft fr Drahtlose Telegraphie, Berlin, Germany, a. corporation of Germany Application April 19, 1939,seri'a1Notasms Y i In Germany May 13,1938l n Claims. (Cl."17^9,1*7l) 'come known for various ultra short wave circuits.

The novelty relates to an arrangement for the amplication of ultra short waves by means of triodes. Circuit arrangements are known as such in which a tube with grid connection on two sides and plate connection on two sides is so connected with outer circuits that the grid-anode 'capacity is compensated by a parallel inductance and that between the cathode and the anode an output circuit is placed, and between the grid and cathode an input circuit. The bringing out, at two sides, of the grid and anode eliminates coupling between the individual circuits. However, it was found that in the case of decimeter Waves the known arrangement does not permit of stable conditions of amplification and that disturbances still appear which render the operating safety doubtful.

'Ihe novelty of the present invention is based upon an appreciation of the fact that these disturbances, despite all the precautionary measures,

are due to a still existing coupling of the individual circuits across the common part of the cathode lead-in, so that no coupling does exist between the input circuit and output circuit and uncontrollable conditions of feed back 'and counter coupling are present.

In accordance with the present invention the said diiculties are overcome by employing means to render impossible a coupling of the circuits across the common cathode lead. Such means include providing the cathode as well as the other electrodes with connections at two sides, so that the grid-cathode circuit can be placed at the one connection point of the cathode, and the cathode-anode circuit at the other connection point. A

Figs. 1 and 2 show two embodiments of the present invention.

The tube structure as shown in Fig. 1 is singleended (in contradistinction to the push-pull type) and is entirely coaxial. y Item K represents the cathode, G is the grid, and A is the anode, whereby respectively towards opposite sides of the tube double electrode connections are provided. 'I'he input circuit is designated by E, the output circuit is O, the compensation circuit for the grid-anode capacity is designated by L, shown in this instance connected between that terminal of the grid opposite the input circuit and that terminal of the anode opposite the output circuit.

In place of the bringing out of the cathode on two sides or in addition thereto, it is also possible to provide a tuning of the cathode lead by inserting a tunable circuit such as has already be- 'the heating lines.

Such a'tuninglikewise leads to avoiding the inuenceofdivsturbing couplings through the common cathodeline. y

g'lhetuned cathode circuit has no bearing on The latter may, moreover, be choked or may be blocked as regards high frequency by inserting blocking circuits. Preferably, the tuned cathode circuit as well as the blocking circuits for the heating line are designed as tunable coaxial lines. Such an arrangement .is shown in Fig. 2 which does not require any further explanation.

What is claimed is:

1. An ampliner for ultra short waves comprising an electron discharge device having anode, cathode and grid electrodes enclosed Within an envelope, each of said electrodes having terminals extending through opposite sides of said envelope, a source of heating energy for said cathode,and a pair of leads from said sourceto opposite terminals of said cathode, an input circuit coupled between the grid and cathode terminals on one side of said envelope, and an output circuit coupled between the anode and cathode terminals on the opposite side of said envelope, and means for neutralizing the capacity coupling between input and output circuits resulting from inherent capacity between grid and anode, said means being independent of both said input and output circuits and comprising a reactance coupled between one terminal of said grid and one terminal of said anode.

2. An amplifier for ultra short waves com- I prising an electron discharge device having anode, cathode and grid electrodes enclosed with- 1n an envelope, each of said electrodes having terminals extending through opposite sides of vsaid envelope, an input circuit coupled between the grid and cathode terminals ori-one lside of said envelope, and an output circuitfcoupled between the anode and cathode terminals on the opposite side of said envelope, and means for neutralizing the capacity coupling between input and output circuits resulting from inherent capacity between grid and anode, said means comprising a capacitive connection from one vend of said grid to the oppositely located end of said anode. l

3. l An amplifier for ultra short waves comprising an electron discharge device having anode,

cathode and grid electrodes enclosed Within an that end of the anode which is opposite the vout-v` put circuit. g n n 4. A high frequency system comprising an electron discharge device h'aving'anode, cathode and grid electrodes enclosed within an envelope, each of said electrodes having terminals Yextending through opposite sides of said envelope, an input circuit coupled between the grid and cathy ode terminalson'bne side ofsaicl envelope, and

an output circuit coupled between the anode and cathode terminals on the opposite side of said envelope, and'means for neutralizing the capacity VVcathode, and a `pair of connections from said coupling between input and output circuits resulting from inherent capacity between grid and anode, said means comprising a capacitive connection from one end of said grid to the oppositely located end of said anode.

5. A high frequency single ended circuit comprising an electron discharge device having anode, cathode and grid electrodes enclosed Within lan envelope, each of said electrodes having terminals extending through opposite sides of said envelope, a source of heating energy for said cathode, and a pair of leads from said source to opposite terminals of said cathode, an input circuit coupled between the 'grid and cathode terminals on one side of said envelope, and an output circuit coupled between the anode and cathode terminals on the opposite side of said envelope, and means for neutralizing the capacity coupling between input and output circuits resulting from inherent capacity between grid and anode, said means being independent of both said rinput and output circuits and comprising a reactance coupled between one terminal of said grid and one terminal of said anode.

ERNST RAHN.