US2227078A - Heterodyne receiver for ultrashort waves - Google Patents

Description

Dec. 31, 1940- E. GERHARD HETERODYNE RECEIVER FOR ULTRA-SHQRT WAVES Filed Oct. 15, 1938 Audio Frey Amp 1. Fre Amp/[flak 0 mmv H wE L m T6 8% V T fiA I MONA d m Patented Dec. 31, 1940 v I I l I l UNITED STATES PATENT OFFICE na'ranonynr. nnonrvnn FOB. ULTRA- snoa'r waves Ernst Gerhard, Berlin, Germany, assignor to Telefunken Gesellschaft fiir Drahtlosc Telegraphic m. b. 11., Berlin, Germany,.a corporation of Germany Application October 15, 1938, Serial No. 235,147 In Germany November 11, 1937 7 Claims. (Cl. 250-9) The invention is concerned with a heterodyne the intermediate frequency transformer 8. The receiver set for ultra-short waves in which a batterysfurmshesasuitable and preferabiynegamagnetron serves simultaneously for the productive biasing potential for the auxiliary electrodes. tion of the local oscillation and for mixing the It has been found that when the auxiliary eleclatter with the incoming wave to produce an trades are negatively biased with respect to the intermediate frequency wave. cathode, the control action thereon is more pre- Heterodyne receivers are known in the prior 'cise because the electrons which pursue spiral art in which a magnetron is used to produce the courses under the influence of the magnetic field local oscillation. Mixing is effected in a separate tend to cluster in the central portion of the rectifier tube. It is also known in the art that discharge zone, whereas if the end-plates were 10 a magnetron tube may be used to rectify the operated at zero bias or positive bias, they would incoming signal waves, the modulation potential attract the electrons so that an insufficient numbeing taken off between anode and cathode. As ber would reach the anodes to become effective an improvement upon the last-named circuit oras output energy of the oscillator tube. Finally ganization it has also been suggested to take off there is an amplifier I!) designed to amplify and 15 the modulation potentials between separate auxrectify the intermediate frequency so that the iliary electrodes and the cathode in order that modulation of the signal wave may be amplified the resonance properties of the rest of the tube by the device I 5 and made audible in the telemay remain unaffected by the potentials so taken phone receiver H.

30 on. The magnetron tube 1 is so adjusted that it In carrying out my invention I preferably emwill generate oscillations whose frequency will ploy an oscillation generator in combination with differ from the'frequency of the signal wave by a rectifier for producing an intermediate frean amount such as to produce the desired interquency wave by heterodyning with the incoming mediate frequency. As has been ascertained by signalling energy collected on an antenna system tests, an intermediate frequency voltage will then 25 designed for ultra-high frequency reception. The be developed between the auxiliary electrodes and local oscillator and rectifier may be combined in the cathode. The local oscillator wave, as known one magnetron discharge tube by inserting therein the art, may, of course, be used in turn as in so-called end plates. According to the method a transmitter wave so that two-way communica- 30 of the invention the intermediate frequency outtion is feasible without circuit changes or changeput is derived from a, circuit which interconnects overs. In this case, for the purpose of moduthe end plates and the cathode through a suitable lation of the transmitter or carrier wave there are direct current source. The local oscillations are required in addition a microphone l2, battery produced in the magnetron discharge tube ciri3 and an audio-frequency transformer M. The 35 cuit which includes the cathode and the seglatter acts upon the end plate potential and thus mented cylindrically formed anode or anodes. upon the frequency of the sending wave.

The sole figure of the drawing shows an exem- I claim:

plifled embodiment of the invention. An aerial l. A two-way heterodyne transmitting and re 3 is connected by way of an energy feeder comceiving apparatus for ultra-short waves compriso prising two down leads to the anode segments ing an oscillation generating magnetron discharge of the magnetron tube I. The anode D. C. potube having a linear cathode, cylindrically segt n ia s suppli d by wa o the radio-fr qu y mented anodes and end plates, a mixer frequency ch k oil 4 whi h is Connected to a i in circuit connecting the cathode to the end plates,

mem r disp s d a ss t e two nduct rs f a constant current source in said circuit arranged 45 a Le h w re ystem by which said down leads to apply a negative bias to said end plates with are constituted. The fiilament of the tube is respect to the cathode, means in said circuit at connected with battery 5. The ma netic field i times operative to modulate the magnetron-genset up by the two solenoids 6 and l of an electroerated oscillations by a. low frequency, and fur- 60 magnet. Mounted within the tube are two auxther means insaid circuit operative at other times 5 iliary electr des which are radially disp sed in to deliver an intermediate frequency which rereference to the filament. These auxiliary eleclt from th heterodyning of incoming ultratrodes are'the same as lateral or wing plates, short waves with said magnetron-generated which are interconnected inside the tube, their 01111 13011 66 terminals being brought out and connected with 2, An ultra-high frequency radio apparatus comprising a magnetron discharge tube having a linear cathode, oylindrically segmented anodes and end plates, a dipole antenna and Leaner-wire transmission system individual conductors of which are respectively connected each to an appropriate one of said anode segments, means for producing a magnetic field in the discharge zone of said tube, means including a direct current source connected between the cathode and the anode segments for enabling said tube to generate oscillations, a circuit connected between the oathode and said end plates, means in said circuit for biasing the end plates negatively with respect to the cathode, further means in said circuit for applying modulationsto said tube, and still further means in said circuit for deriving an intermediate frequency output current as the product of heterodyning the oscillations locally generated with incoming signalling energy collected by said dipole antenna.

3. In an ultra-high frequency communication system in which oscillations are generated in a magnetron discharge tube having segmented anodes, a linear cathode and end plates, the method of conducting a two-way communication which comprises heterodyning incoming signalling enersy with the locally generated oscillations to produce at times intermediate frequency wave potentials between the cathode and the end plates, and at other times impressing modulation potentials on said end plates thereby to radiate modulated high frequency energy from said system when desired, and maintaining a constant negative bias on said end plates with respect to said cathode.

4. Apparatus for heterodyne reception of ultrashort waves comprising a magnetron discharge tube having a linear cathode, cylindrically segmented anodes surrounding the cathode, and end plates, means for collecting said waves and applying them contraphasally to opposing segmented anodes, means for producing oscillatory potentials between said cathode and said end plates which beat with said waves, means for negatively biasing said end plates with respect to said cathode, and means-for deriving intermediate frequency potentials between the cathode and the end plates.

5. A duplex radiocommunicating station comprising apparatus as defined in claim 4 in combination with means for impressing low frequency modulation potentials between the cathode and the end plates thereby to reverse the action of the means for collecting and applying the ultrashort waves and to cause ultra-short wave signaling energy to be radiated.

6. An ultra-high frequency two-way communication system comprising a, magnetron discharge tube having segmented anodes, a linear cathode and end plates, means for generating oscillations in said tube, means operative at times for heterodyning incoming signalling energy with said oscillations to produce intermediate frequency wave potentials between the cathode and end plates, means operative at other times for impressing modulation potentials on said end plates thereby to radiate modulated high frequency energy from ERNST GERHARD.

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