US2125982A - Regenerative receiver - Google Patents

Description

A 1938- P. BELLEVILLE 2,125,982

REGENERATIVE RECEIVER Filed April 1, 1937 AAAAAAAA c6 RBELLEl ILLE ATTORNEY y 50 wise brought back to the circuit Llcl across two ditions for sustaining oscillations of the system, 50

Patented Aug. 9, 1938 A UNITED TATES PATENT OFFICE REGENERATIVE RECEIVER Paul Belleville, Paris, France, assignor to Compagnie 'Generale de Telegraphic sans Fil, a cor-' poration of France Application April 1, 1937, Serial No. 134,228 I In France April 8, 1936 v I Claims. (01.250-20) It is known that in the ordina y regeneras the self inductance L1 with which they are tive receivers, the amplification due to the feedcoupled. back is limited by the appearance or distortions The two rectifiers may be dry rectifiers, diodes, and in the cases of modulated telephony or telegd o tubes any Similar ea s- I s e me 0 ca e superregenera on per s of carrying the feedback much further by obligfeedback in the circuit L1C1 only during one of ingt t t t t reassume periodically t the alternations. The coils Z1, Z2 act on the other stability. This circuit has serious disadvantages hand, in the Oppo t e, tho One of which caramong others Iiltis liackdof steficlitivity afigdthetapf; bi lg gotogziao it ia ze iiat fion-zi a positiltl'e arance of a. ss ng ue e so ca -cu -o e e. en s o ecrease e Zi which is difli ult to elimmma damping of the circuit L1G! and to favor the sus- T method and circuits forming t ubject tenance of the oscillationsof this circuit, while matter of the present invention, has for its the other one which acts during the other alterject to obtain large amplifications while conservnation, carries a negative feedback potential 1. e. m a selectivity campatible t a favorable it tends to increase the damping of the circuit b. i ggZ fSL Z JZQS Z T ZS IQ releasing a in correct phase, i. e. respectively in phase and phase opposition with theoscillations induced in 20 fgedback g g fi i f sgg gg i fi the antenna, and in order that on the other hand,

t e same 8 gn s-gna 8 i the time constants of the two feedback paths be cult while an a tematlons of 53 s a? sufiiciently low thus providing suificient time for duce an inverse phenomenon Q g g e this feedback to act during the duration of arangement of the system (tubes and oscillatory single alternation, in these two paths the above circuits) to resume its Stability indicated control elements R1 In C: and C4 are" 0 The invention will be better understood by reinserted. These elements will be controlled in femng to accompanying figures showing by such, a manner that the feedback phases are corway of example and without limiting the mven' rect for an intermediate frequency of the range tion thereto, various modes of constructions. of the receiver. Owing to theintmduction m 30 In the drawing, Fi ure 1 illustrates a high these circuits of sufiiciently high resistances, it quency St having, applied to it regeneration is furthermore achieved that the phase displace- 1 in accordance with the present invention; ments remain low (of the order of a few degrees Figure 2 is a schematic representation of the for instance) even for the ends of the range, invention applied to a detector circuit; and,

. without subsequent adjustment of the tuning 35 Figure 3 illustrates schematically a circuit control of these circuits. It should be noted that lizlng the inve in conjunction with a this last arrangement which forms one of the funct on t eparticular features of the inventiomls a very Fig. 1 shOWS' in Schema-Heal manner a high general one, and can be applied to many circuits f equ n y amp fier sta wit regeneration in with simple regeneration. The rheostats R2 and 40 acco dan e With the invention In this figure R3 finally permit of controlling the value of the there is shown at H an amplifier tube having feedback potentials carried respectively by each in t e grldclml-nt and Plate circuit 9W0 resonance of the. two paths to the oscillatory circuit L101.

, circuits LiCl and 112C: which can preferably be According to a, possible explanation of the tuned to the carrier frequency y means of a phenomena, one of the advantages of the meth- 45 co mo drive means The slsnals as od forming the subject matter of the present ceived t t antenna A are transmitted to the invention appears to reside in the possibility of circuit Llcl by the mutual induction of the coils bringing the positive feedback in the one of the L and L1- The feedback Potential at B is likealternations to a value which surpasses the condi e e Paths including the resistor 1, e se but acting in the opposite sense in the other alinductance L3, the condensers C3, C4 the rectiternation in such a manner that these oscillafiers d1, 012 connected in opposition, the two varitions cannot continue. In fact it is found that able resistors R2, R3, and finally the two induc the apparatus is very sensitive, with 'suflicient setion coils Z1, Z2 acting in opposite directions upon lectivity, and that the control of the intensity 55 accordance with the apparatus.

The circuit of Fig. 1 indicates only the circuit of a high frequency stage with regeneration in invention. It will however be understood that this stage could act thereafter on another stage, detector, low frequency ampliand r the connection iler etc., not shown for the sake of clearness in the drawing.

Fig. 2 shows schematically a particularly interesting mode of embodiment of the invention applied to a detector tube D operating for instance with grid current. There is shown in C leakage resistor. The other elements of the circuit are the same as in Fig. l and have the same reference characters. The high frequency potential of the feedback is also derived at B and applied in the inverse sense across two different paths to the circuit L1C1 which receives the oscillations of the antenna. The detected oscillations derived at E at the terminals of the resistor R. are hereafter applied to all suitable audio-frequency amplifier stages designated by ER across a connection condenser C for instance, and a potentiometer Rs serving for the volume control.

Fig. 3 finally represents by way of example only, a mode of embodiment of the invention in which the two rectiflers d1 d: and the first stage BF are obtained from. a single double diode and pentode K,for instance. The two rectiflers are hereby formed 'of two diode elements d1 ii: of this tube and the pentode part serves as audifrequency amplifier. In this circuit, the detector tube is likewise shown in the form of a pentode J, but it should be understood that these representations are not limiting the invention.

The functioning of this circuit is as follows: when a signal arrives at the grid ll, only the alternations which render the plate positive benefit the'feedback phenomenon since the diodes can only function when they are positive, while the opposite alternations of the signal impart tothe grid circuit Llcl an impulse in the inverse sense which tends to oppose the excitation of oscillations. This latter phenomenon is controlled by the construction by adopting a suitable value for the resistor Ra, while the feedback can be controlled at will by the operation of the variable resistor R2. The audio frequency voltage developed across resistor R4 is, as in Fig. 2, transmitted through condenser Cs and lead I! to the signal control grid I! of the pentode amplifier K, the plate of which is resistance coupled by condenser and the usual resistor R8 and condenser C1 to the input terminals of any suitable translating device HP.

Having described my invention, what I claim and desire to secure by Letters Patent is:

1'. An amplifying device comprising in combination, an electron discharge tube having an input circuit and an output circuit, means for impressing an alternating signal voltage on said input circuit, a feedback connection between said output and input circuits arranged to cause regeneration of said input circuit, means for making this regeneration operative during one half of the signal voltage cycle and a second feedback connection between said output and input circuits arranged to cause degeneration of said input circuit, and means for making this deenergization operative during the opposite half of the. signal voltage cycle.

2. An amplifying device comprising in combination, a vacuum tube having a cathode, a signal grid and an anode, an input circuit connecting said signal grid and cathode, an output circuit connected to said anode, means for impressing an alternating signal voltage on said input circuit, a feedback connection between said output and input circuits including a rectifier, and a second feedback connection between said output and input circuits including a second rectifler, said rectifiers being poled in opposite directions.

3. An amplifying device comprising the combination of a vacuum tube having a cathode, a

signal grid and an anode, a circuit tuned to a desired signal frequency connecting said signal grid and cathode, an output circuit connected to said anode, means for impressing an alternating signal voltage on said resonant circuit, a feedback connection between said output circuit and said resonant circuit including the series connection of a resistor and a rectifier and a second feedback connection between said output circuit and said resonant circuit including the series connection of a second resistor and a second rectifier, said first and second rectifiers being .poled in opposite directions 4. A radio receiver comprising the combination of a vacuum tube having a cathode, a signal grid and a plate, an input circuit connecting said signal grid and cathode, an output circuit connected to said plate, a second vacuum tube having a cathode and two anodes, a feedback connection between said plate and input circuit including a coil connected to one of said anodes, and a second feedback connection between said plate and input circuit including the series connection of a second coil and the other of said anodes.

5. The arrangement of claim 4 in which each of said feedback connections includes a series connected stopping condenser.

PAUL BEILEVILLE.

Images