US1982694A - Superregenerative receiver - Google Patents

Description

Dec. 4,1934. w. VAN B ROBERTS v 1,982,694 SUPERREGENERATVIVE RECEIVER Original Filed March 30, 1929 WALTER VAN mosms Patented Dec. 4, 1934 1,982,694 I SUPERREGENERATIVE RECEIVER Walter van B. Roberts, Princeton, N. J., assignor to Radio Corporation of America, a corporation of Delaware Application March 30, 1929, Serial No. 351,411 Renewed June 22, 1931 t 1 35 Claims (c1.250-2'0) The present invention relates to regenerative understood by reference to the following descripsystems, and, more particularly, to a novel tion taken in connection with the drawing in method of, and means for, producing super-rewhich I have indicated diagrammatically one cir-' generation in a receiving circuit. cuit organization whereby my invention may be 5 In the well known type of super-regenerative carried into effect. I 60 receiving systems there exists a defect whichhas The illustrated circuit shows a. source of superhandicapped their wide-spread use. It is known audible frequency current F coupled to a-circuit that one of the disadvantages of the super-re- L, C tuned to the frequency F. The circuit L, C is generative receiving circuit is the fact that when connected to a pair of triodes 1, 2, of similar charradio frequency feed back is made strong the acteristics, each of which triodes hasinserted in 65 interrupting super-audible frequency does not its plate circuit a feedback coil shown by T and Tr, fulfill'its function completely enough. i That is to respectively, magnetically coupled to a coil L1. say, before the full effect of the super audible The grid of each triode is biased, as shown, both frequency damping is achieved, the regenerative grids being, for example, equally biased throu h amplifier tube begins again to build up the incomhigh resistance R which is preferably connected ipletely qu n d lat ns, pr ducin more to the middle of coil L, and through the common or less sustained radio frequency oscillations. parallel resonant circuit L1, C1 to a point on the Now,'I have discovered a method of positively filament circuits. of the triodes 1, 2. stopping, during the damping period, Oscillations The feedback coil T, connected in the plate-cirof a y s n th at may be built up du ing the cuit of triode 1, is connected to the reversed feedamplifying p e arrangement devised by back coil Tr, the latter coil being connected in me to embody this method utilizes a feedback, the plate circuit of triode 2. A source of plate, whichI term a reverse feedback, i opposition to potential, and a utilization means, such as the amplifying feedback, a d t e ev s d feed? phones, are common to the output circuits of the 25; back action is periodically substituted for the t i 1 2 A usual by-pass condenser is regenerative feed back by the interrupting superh t d across th phones audible frequency current. The circuit L, C is fixedly tuned to the super- Acoord y. t is one of the main objects of audible frequency F. It will beseen at once that my present invention to provide a method of, and ith the arrangement shown, when the grid of In producing Supe in a triode l is less negative than normal, the grid ceiving circuit-which comprises utilizing areverse. of triode 2 l be more negative t normaL feedback action o rapid quenching of radio While-the grid'of triode2 is very negative, the fr qu y oscillations dur n thedampineperied, triode 2 is ineffective. But, it should be noted without introduc pp e da p into the that the grid of triode 1 is only slightly negative,

35 oscillation circuit during the regeneratively and, due to the action of feedback coil '1' and coil amplifying, or building up, period. L1, triode 1 builds up oscillations in the radio Another important object of the invention is to frequency it, the amplitude at a given'time provide a receiving circuit of the super-regendepending upon th signal input i erative type in which a pair of triodes of similar Due t th reversing ti of th superhudl 40 characteristics is utilized, one Of the triodes funcible frequency energy F, the grid of triode 1 next tioning as the a p fi and having a feed-back becomes very negative, while the grid of triode 2 coil associated therewith, the other triode having becomes only slightly negative. This results in a second feed-back coil associated therewith and the reverse feedb k coil T building d or fu ct o g as a reverse feed-back means, positively quenching the oscillations, thus taking 45 entire op a of t amplifying action being the place of ohmic resistance in quenching oscilinitiated y an interrupting supcr-audiblev i lations at super-audible frequency. It should. q y i such a manner that the reverse feedalso be noted that the method described hereback mea s begins to quench oscillations in the in allows the use of another tuned circuit loosely amplifier triode prior to the instant when oscillacoupled t t radio frequency circuit, Since th '50 #0 5 of e amplifier Would otherwise attain an reversed feedback may be increased to suchexundesirable amplitude The novel features which tent as to wipe out residual oscillations in this Ibelieve to be characteristic of my invention are extra circuit a1s0 set forth particularity in t e pp c cla In other words, the arrangementl have. shownh Invention itself, however, t o 1175 makes it possible to connect a pre-selector cir- 55 i e i and method f operation will b t be cuit as, for instance, a band-pass circuit, or a 11.0

tuned stage of radio frequency amplification, or an untuned stage of radio frequency amplification, or all three, or any two between the antenna and the radio frequency circuit L1, C1.

The reactions and interactions taking place in the circuit may be illustrated by the following mathematical expressions, the latter serving the purpose of laying down rules of design, whereby anyone, skilled in the art, may construct the circuit of this invention. It can be shown that the feedback from the tickler 'I is proportional to,

cn-E sin Ft The feedback from the coil Tr is proportional to,

(-a2E sin Ft) The total feedback, therefore, is equal to,

(a1-(l2) -2E Sin F15 It is merely necessary to keep the constant term (ii-a2 of a negative value, or of suficiently small positive value that it is not enough to completely wipe out the ohmic resistance of the radio frequency circuit, in order to produce the action described heretofore, it being understood that,

a1=the amount of negative resistance fed back to the input circuit in the absence of E,

az=the amount of positive resistance ffed back to the input circuit in the absence of E,

E=the maximum extra resistance fed back when the peak voltage of frequency F is applied to the grids. n

It is to be observed that a further advantage of this circuit resides in the fact that the voltage of frequency F being differentially applied to the grids, the current through the phones does not vary at frequency F to nearly so great an extent as in the ordinary single tube super-regenerative arrangement, where there must be large currents of interruption frequency through the phones, unless elaborate filtering arrangements are used to separate such currents from the desired signals. I

In the drawing it is to be understood that the source of energy to be amplified is coupled or otherwise connected across the coil L1.

While I have indicated and described only one system for carrying my invention into effect, it will be apparent to one skilled in. the art that my invention is by no means limited to the particular organization shown and described, but that many modifications in the circuit arrangement, as well as in the apparatus employedjmay be madewithout departing from the scope of my invention as set forth in the appended claims.

What I claim is: I

, i. A super-regenerative receiving circuitcomprising a pair of triodes of similar characteristics having grid and plate circuits, a tuned circuit common to the grid circuits of both triodes, one of said triodes having its plate circuit coupled to the tuned circuit in its grid circuit, the other triode having its plate circuit reversely coupled to said tuned circuit, and'a source of interrupting current coupled to the grid circuits of said triodes said current being of a super-audible fre} nant circuit in a reverse manner, a source of interrupting current coupled to said input circuits, the current being of a super-audible frequency, the resonant circuit being tuned to said frequency.

3. A method of operating a super-regenerative receiver provided with an amplifier employing a feedback action and a reverse feedback action which consists in subjecting signal energy to the amplifier employing the feedback action, subjectingthe signal energy to the reverse feedback action, in opposition to the amplifying feedback,

and periodically rendering the reverse feedback operative thereby positively stopping oscillations of any strength that may be built up during the amplifying period.

4. A method of operating a super-regenerative "receiver which consists in subjecting signal enreverse feedback operative thereby positively stopping oscillations of any. strength that may b built up during the amplifying period.

5. A method .ofoperating a super-regenerative receiver which consists in feeding thesignal energy to the receiver and. subjecting signal energy to an amplifying feedback action, supplying an interrupting current of super-audible frequency to the receiver, and utilizinglthe interrupting current to periodically impress a reverse feedback action, in opposition to the amplifying feedback, for the amplifying feedback. 6. In asuper-regenerative amplifier provided with a signal input circuit and an output circuit, themethod of maintaining a definite relationship between the amountcf damping action during the damping period and the amount of undamping action during the building up period which includes the steps of applying signal energy to the amplifier, feeding back energy from the amplifier output to the input thereof in regenerative phase, feeding back energy to the amplifier input in degenerative phase and periodically and harmonically varying the strength of both feedbacks in inverse sense so that the equivalent-single resultant feedback is alternatively regenerative and degenerative in phase.

'7. The method of operating a super-regenerative receiver which consists in feeding the signal energy to the receiver and subjecting signal one ergy to an amplifying feedback action, supplying an interrupting current of super-audible frequency to the receiver. feeding back signal en ergy, in opposition to theamplifying feedback, and utilizing the interrupting current to periodi cally substitute the opposing feedback for the amplifying feedback, forrapid quenching of radio frequency oscillations during the damping period.

8. A method of operating .a supereregenerative receiver which consists in feeding the signal en ergy to' the receiver and subjecting signal energy to an amplifier employing a feedback action, supplying an interrupting current of super-audible frequency to the receiver, subjecting the signal energy to a reverse feedback action, in opposition to the amplifying feedback, and utilizing the interrupting current to periodically substitute the reverse feedback for the amplifying feedback thereby positively stopping radio frequency oscillations during the damping period.

9. In a feedback circuit, themethod of securing great amplification without building up sustained oscillations which comprises periodically reversing the phase of the feedback.

10. The method ofiamplifyingivarying electric currents which comprises impressingthe varying potential of the currenttozbe amplified upon a feedback circuittand periodically reversing the phaseof the feedback whereby super-regenerative,

action i's'obtained." l l1. The method of amplifying varying electric currents which comprises impressingthe varying potential of the current tobe amplified upon a system including feedback means and counterfeedback means andwperiodicallyaltering the relation between the amount of feedback and the amount of counter-feedbackcf the system, whereby superregenerative actionis' obtained.

12. The methodof amplifying varying electric currents which comprises impressing the varying potential of the current to be amplified upon a system including a feedback circuit and a counter-feedback circuit and periodically" varying the relation between the amount of feedback and the amount of counter-feedback; at some frequency a system: including a feedback circuit and also" upon a counter-feedback circuit and periodically varying both the amount of feedback and the amount of counter-feedback whereby super-regenerative action is obtained.

15. The method of amplifying varying electric currentsiwhich comprises impressing the varying potential of the current itosbe'amplified upon a system including feed-back means. adjusted near the'pointnof oscillation and'a counter-feedback means and periodically "varying the. relative amountszof feedback and 'of V counter-feedback whereby thelnet amount :of -feedback varies periodically about said value which is near the point of oscillation. 1'

a 16; The method of amplifying varying electric currents which comprises impressing the varying potential. ofthecurrent tozbe amplified upon a system including a feedback circuivand upon a counter-feedback circuit and periodically varying 'both thelamount of thefeedbackan'd the amount'of the counter-feedback'ofsaid circuits at some frequency relatively low as compared: to the frequency of the current to be amplified whereby super-regenerative action is obtained. 2 i

put and output circuits coupled so'as to produce a feedback system, a second thermionic tube having input and output circuits coupled so as to produce a counter-feedbacksystem; means for impressing said energy uponiboth said systems and meansassociated with both said systems for periodically altering thesrelationzbetween the amount of feedback andthe amount of counter-i as to produce a feedback system, a second thermiof feedback and the amount a offoscillation and means for periodically varying 1 17, Apparatus for amplifying varyingielectricl energy comprising a' thermionic tube having in onic tube having input and output circuits coupled was to produce a counter-feedback system, said two systems having common input and output circuits and means for periodically varying the relation between the amount of feedback and the amount of counter-feedback at some frequency relatively low compared to the frequency of the current to be amplified; i r 19. Apparatus for amplifying varying electric currents comprising-a thermionic tube havinginput and outputcircuits coupled so as to form a. feedback circuit, a second thermionic tube having input and output circuits coupled so as to form a counter-feedback circuit, said two :circuits having common input and output circuits, means for impressing the potential of saidcurrents-on said common input circuit thereby causing said feedback circuit to. generatev oscillations and means for periodically varying theamount of counter-feedback in said counter-feedback circuit thereby stopping the generation of oscillations in said feedback "circuit whereby 'superregenerative actionis obtained. i i

20. Apparatus for amplifying varying electric currents comprising a thermionic tube having input and output circuits coupled so as to form feed-back circuit, a second thermionic tube having input and .output circuits coupled so as toform a counter-feedback circuit, saidtwo circuits having common input and output circuits, means, for impressing the potential of said currents upon the inputs of both said circuits and means differentially applied to the inputs of said feedback and counter-feedback circuits for"periodically varying the amountof counter-feedback in said counter-feedback a circuit, said circuits being adapted to generate oscillations in accordancewith the action of the feedback circuit and to prevent the generation of oscillations in accordance with theaction of the counter-feedback circuit'whereby super-regenerative action is obtained. 5

-21. Apparatus for amplifying varying electric currents comprising a'thermionic tube having input and output circuits coupled-so as to forma a feedback system, a second thermionic tube havingcoupled input and output circuits soas to formra counter-feedback system, said systems havinglcommon input and output circuits and means for periodically varying both the amount of counter-feedback ofsaid system. H

I 22. Apparatus for amplifying varying electric currents comprising, a thermionic tube having input and .output'circuits coupled so as'to "forr'ni a feedback. system, a second thermionic tube having inputv and output circuitscoupled so as to. form a counter-feedback system, said system s having common input and output circuits, said feedback system being adjustednear the point thewamount of feedback with "respect to the amount of counter-feedback of saidsy'stemsi x 23; Apparatus for amplifyingyaryingelectric;

currents comprising, a thermionic tubefeedback system having an input circuit and an output circuit, a thermionic tube counter-feedback sys" tern having an input circuit andnan output circuit,.

a portion ofieach of said two input circuits being 24. In a super-regenerativev circuit an electron discharge tube. regenerative system comprising a. feedback circuit in combination with an electron discharge tube degenerative system comprising a counter-feedback.circuit, means for adjusting said. regenerative system near the point of oscillation, a source of oscillations associated-with both said systems and means controlled thereby for causing a periodic. variationin the relation between the amount of feedback in said feedback circuit and the amount of counter-feedback in said counter-feedback circuit.

25. In a super-regenerative receivermeans for amplifying varying electric currents comprising a feedback system and a counter-feedback sys-- tem, said two systems having common input and output circuits, means for. periodically varying both the amount of feedback and the amount of counter-feedback of said systems at some frequency relatively low compared to the'frequency of the current to be amp1ified, the amount of' counter-feedback being of suchan extent that it influences circuits coupled to said system but periodically varying the total effective resistance of said circuit about. a mean value greater than zero and means for making the maximum posi tive value of effective resistance of. said. circuit.

greater thanthe natural ohmic resistance of the oscillatory circuit.

. w .1 2'7. Inv apparatus for amplifying varying elec-* tric currents, a resonant circuit, means for vary- 5 ing the net eifectiveresistance of said resonant circuit periodically about a mean positive value at afrequency low comparedto the natural frequency of said resonant circuit and meansfon making, the maximum attained positive value of -.efiecti-ve resistance greater than the natural ohmic resistance of the, resonant circuit.

28. In apparatus for amplifying varying electric currents, an oscillatory circuit comprising re-- generative means and degenerative means, means,

for periodically varying the total effective resistance of said circuit about a mean value. greater than zero and means comprising said degenera-.

tivemeans for making the maximumpositive value of effective resistance of said-circuit greater.- than the naturalohmic resistance thereof;

29. In a super-regenerative circuit,;a pair of signal energy transferred from said source to said tuned circuit being adapted to affect both thermionic tubes in like sense, a source of super-audible frequency waves differentially coupled to both said input. circuits, means forcoupling the output circuit of one of said thermionic? devices to its input circuit in a sense to cause regenerationand means for coupling the output and input circuits of the other thermionic device in a sense to'cause de-generation.

30. In a super-regenerative circuit, a" pair of thermionic tubes having input and output circuits, the two input circuits'-"having a common. portion including a tuned circuit and the two out-- put circuits having a common. portion including a load circuit, means for couplingasource of Signal energy to said commontuned circuit, the signal energy transferred from said source-to ,saidwtuned. circuit being adapted to affect both thermionic; tubescin like sense, means for cou pling' the output circuit of one of said thermionic devices to its input. circuit in a sense to cause regeneration, means for coupling theoutput. and input circuits of the other thermionic. device in a sense. to causedegeneration, and means comprising asource. of supersonic. frequency waves for alternatelvrendering said two circuits inoperative'.

31. Ina super-regenerative receiver, a regenerative circuit including a space discharge device, damping meansv forsaid regenerative circuit comprising a degeneration circuit including aspace discharge device, a source of signal energycoupled tobothsaid circuits, 2. load common to both circuits and means for rendering said circuits alternately and periodically operative and inoperative.

32.'.,The method. of signal wave amplification which comprises building up oscillations to an intensity many times greater but proportional to the intensity ofv the signal wave to be amplified and periodically reducing to a substantial degree the intensity of the built uposcillations at a super-audible'rate,thebuilding-up rate of the oscillations being substantially lower than the reduction rate.

33. In a super-regenerativecircuit comprising at least oneelectronic tube provided with an in-' put circuit'and an output circuit, asource of interruption frequency voltage coupled to one of saidcircuits,.an audio output circuit connected to the output of said device and means for opposingv in said audio. output circuit the current of interruption frequency fed. thereto from said electronictube.

3.4. In a super-regenerative circuit including at least one electronic discharge tube provided with input and output circuits, .9. source of interruption frequency voltage coupled to said input circuit, an audio. output: circuit connected to. the output circuit of said device, and means for opposing in said audio output circuit the current of interruption frequency fed thereto through the electronic tube, said means comprising a circuit arrangement including said audio output circuit and adapted to cause a current to flow through the audio output circuit of phase and magnitude -.to substantially neutralize the effect. of said. current of interruption frequency flowing through the; audio-output circuit.

35. In a super-regenerative circuit including at least one electron discharge tube provided with an input circuit and an output circuit, an audio output circuit connected to the output circuit of said tube,.a source of. interruptionfrequency voltage connectedto one of said electron discharge tube circuits so. as to transfer interruption frequency energy thereto whereby energy of said interrupting frequency is present in the output circuit of said tube, means for opposing in said audio output circuit the energy of interruption frequency fed theretofrom the tube output circuit comprising a circuit arrangement including said audio outpute'circuit and adapted. to cause a current to flow through the audio output circuit of. such phase and magnitude. as to substan tially neutralize the effect of the energy of interruption frequency transferred. to the audio output circuit from the tube. output circuit.

WALTER VAN B. ROBERTS.

Images