US 2526267 A
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Description (OCR text may contain errors)
Oct. 17, 1950 .1. J. OKRENT SUPERREGENERATIVE WAVE-SIGNALYTRANSLATING svsmm Filed Sept. 24, 1946 IN VEN TOR.
JA PER J. OKRENT W ATTORN Y i atented 1 7,
SUPERREGENERATIVE WAVE-SIGNAL I TRANSLATING SYSTEM Jasper J. 0krent, Great Neck, N. Y., assignor to Hazeltine Research, Inc., Chicago, 111., a corporation of Illinois Application September 24, 1946, Serial No. 698,997
\ erative receiver essentially comprises a regenerative oscillatory circuit the conductance of which is controlled to have positiveand negative values during alternate operating intervals. The conductance variations characteristic of superregenerative operation may be obtained by virtue of self-blocking effects within the regenerative circuit or, for arrangements of the type to which "this invention particularly relates, mayv result from'the influence of a periodic quench voltage supplied from an oscillator or other source external to the regenerative circuit. Where a separate quenching source is utilized, it is customary to adjust the degree of regeneration, the operating bias of the regenerator, and the amplitude of the quench voltage for optimum reception.
Receivers adjusted in this manner have proved to be satisfactory for most installations but they are subject to one operating limltation'which may be objectionable in certain cases. Specifi- 1 cally, the amplitude of the quench voltage tends to vary with such factors as the voltage regulation, tube characteristics, etc. in the quench os- Where the quench voltage does experience a change in amplitude, the operating conditions required for optimum reception no longer prevail and the response of the receiver is adcillator.
It is an object of the present invention, therefore, to provide a new and improved superregen- Lerative wave-signal translating system which at least partially'avoids the aforementioned-limitation of prior arrangements;
It is another object of the invention to-provide a new and improved superregenerative waveesignal translating system of the type that features a separate quench-voltage source and is charac terized by an operating bias which'varieswith T amplitude variations inthe quenching voltage.
It is a specific object of theinvention to provide a new and improved superregenerative receiverhaving an external quench supply and a biasing arrangement which compensates for amplitude variations of the quenching voltage.
A superregenerative wave-signal translating system in accordance with the invention is of the separately quenched type and comprises a regenerative oscillatory circuit and an'oscillation generator, including a self-biasing means, for aphplying a periodic quench voltage to the regener- 2 ative circuit to control the conductance thereof to have positive and negative values during alternate operating intervals, as required to provide superregeneration. The system also has means for deriving-from the self-biasing means of the generator and for applying to the regenerative circuit a unidirectional bias potentialhaving a magnitude determined by and variable with the amplitude of the quench voltage;
For a better understanding of the present invention, together with other and further objects thereof, reference is had to the following description taken in connection with the accompanying drawing, and its scope will be pointed out in the appended claim. I r
In the drawing, Fig. 1 is a schematic representation of a superregenerative receiver embodyingthe present invention; and Fig. 2 represents a modified receiver arrangement also embodying the invention.
Referring now more particularly to Fig. 1, the wave-signal translating system there represented is a superregenerative receiver that is of conventional design and construction except for the potential-supply arrangement which embraces the .invention and renders the receiver performance substantially independent of amplitude variations of the quench voltage. As illustrated, the receiver comprises a regenerative oscillatory circuit including a triode-vacuum tube ll] having anode, cathode and control electrodes. The operating frequency of the regenerative circuit is determined by the parallel combination of an inductor H and a condenser i2, the latter being represented as 'a variable element to facilitate adjusting the operating frequency to a desired value. The resonant circuit ll, 12 is coupled to the anode and control electrodes of tube it) by way of condensers l3 and M, respectively. A tap of inductor l I is grounded as is the cathode of tube II] to provide regeneration. inconventional manner. The anode of the tube is connected'to a sourcev of space current +B by way of a filter and an anode resistor IS. The filter includes serially connected signal-frequency chokes l6 and I? as well as intermediate shuntconnected condensers I8 and I9.
Super-regenerative operation is achieved by i controlling the conductance of the described requency-determining circuit of the quench oscillator comprises an inductor 26 in parallel with an adjustable condenser 27 and is coupled to the control electrode of tube 25 through a grid condenser 28 and a grid-leak resistor 29. The anode of tube 25 is effectively connected with the frequency-determining circuit by means of a condenser 30, while the cathode thereof is directly coupled to a tap on inductor 26. A source of space current +13 is coupled to the anode of the tube through a resistor 3| and the quench-signal output is derived from the cathode circuit for application to tube ll] of the regenerative circuit through a condenser 32 and a radio-frequency choke 33. A by-pass condenser 34 is associated with the output connection from the quench scillator to isolate radio-frequency signals therefrom. The quench signal supplied by oscillator may have a sinusoidal or other suitable wave form but has a frequency which is low With referenceto the operating frequency of the regenerative circuit including tube It.
A unidirectional bias potential for regenerator .lllis obtained from means, included in the osciltending from a tap on resistor 29 and including a resistor 35 provides means for applying a bias potential derived in a circuit of the quench-frequency oscillator along with the quench voltage to the control electrode circuit of regenerator tube [0.
A condenser 58 couples adetector system to the regenerative circuit for detecting the signal outputthereof to obtain the desired modulation components of a received signal. The detector system has a diode and its load circuit includes a signal-frequency choke 42 and a resistor d? by- 1 passed by a condenser 4 The output signal of the receiver may be derivedfrom the load circuit of the detector and supplied to any suitable utilizing circuit (not shown) as indicated by the arrow Received signals may be applied tothe receiver from an antenna-ground system .56, in-
. eluding an inductor 4? inductively coupled with resonant circuit H .i 2.
In considering the operation of the receiver, it will be understood that the degree of regeneration of the regenerative circuit and the bias applied thereto from resistor 29 are adjusted with reference to the normal value of the quench voltage to effect optimum wave-signal reception.
1 The quench voltage controls the conductance of the regenerative circuit, causing it to have positive and negative values in alternate operating intervals in conventional superregenerative fashion. The oscillations generated in the circuit of tube IE] during negative conductance intervals are applied to detector M. These oscillations carry the modulationof the received signal which is obtained in the detector system and delivered to the utilizing circuit.
Grid current flows in the circuit of tube 25 during the peak-amplitude periods of the generated quench oscillations. This flow of grid current is equivalent to peak rectification of the quench voltage and develops across resistor 29 a substantially unidirectionalbias potential having a magnitude which is determined by and variable with the amplitude of the quench voltage. This potential accomplishes two functions. It serves as a self-bias for the oscillator and, through the tap of resistor 29, it is used as an operating bias for the regenerator tube I8. Inasmuch as the bias thus applied to regenerator tube 10 is obtained directly from and varies in the same sense as the amplitude of the quench voltage, it compensates for any amplitude changes in the quench voltage, thereby maintaining the superregenerative action substantially independent of variations in the quench amplitude as required to maintain optimum reception.
In the modification of Fig. 2 the regenerative circuit includes a section S1 of a duo-triode tube 56. The frequency-determining circuit in this case is provided by an inductor 5! and a condenser 52, shown in broken-line construction since it may be comprised in whole or in part of the distributed capacitance of inductor 5| and associated stray capacitance effects. One terminal of this circuit is grounded and the high-potential terminal thereof is connected to the control electrode of tube section S1 through a condenser. 53. The cathode of this section is grounded and the anode circuit includes an inductor 54 coupled with inductor 5i as a feed-back connection.
The quench oscillator in the Fig. 2 embodiment comprises the alternate section S2 of tube 56. Its frequency-determining circuit is provided 'by an inductor 55 and a condenserifi. Condenserliii is also connected with theanode circuit of tube section S1 and applies the generated quench voltage to the anode-cathode circuit of the regenerator. Resonant circuit55 56 is also coupled to the control electrode of tube section S2 through a condenser 5i and a grid-leak path including serially connected resistors 58 and 59. The latter is bypassed by a condenser 50 and has a tap from which a bias potential is derived and applied by Way of a signal-frequency choke El to the control electrode of regenerator tube S1. A source of space current +3 is connected to the anode element of tube section S2 through an inductor 62 which also aifords the required feedback for the quench oscillator.
A detector system, including a diode M, is coupled to the regenerator in a manner similar to that described in connection with Fig. 1 and furnishes the output signal of the receiver to a utilizing circuit as represented by the arrow 45. An antenna-ground system 65, including an inductor 66 coupled to inductor5l, is provided for applying received signals to the regenerative circuit.
The arrangement of Fig. 2 is essentiallythe same as that of Fig. 1 and their operation is generally similar. It will be noted, however, that in Fig. 2 the only potential applied to the anode-cathode circuit of the regenerator tube 81 is the quench voltage, there beingno directcurrent potential included in this path. The
advantage in this is that the bias applied to the For this reason the performance of the receiver is improved over those arrangements'whereinf there is n 'cOmpens'ating relationship between the quenchgamplitude and the regenerator bias.
While Vere have been described what are at present considered to be the preferred embodiments of th invention, it will be obvious to those skilled in the art that various changes and modifications be made therein without departing from theflinvention, and it is, therefore, aimed in the appended claim to cover all such changes and modifications as fall within the true spirit and scope a: the invention.
What is claimed is: v
A superregenerative wave-signal translating system of the separately quenched type comprising: a regenerative oscillatory circuit; an oscillationg'enerator, including a self-biasing means, for applying a periodic quench voltage to said circuit to control the conductance thereof to have ,positive and negative values during alternate operating intervals to provide superregeneration flgand means for deriving from said self-biasing means of said generator and for -app1ying7to said circuit a unidirectional bias potential-having a magnitude determined by and 'variableiwith the amplitude of said quench voltage.
JASPER J. OKRENT.
REFERENCES CITED The tol lcwing references are of record in the file of Patent:
f UNITED STATES PATENTS Number Name Date 2,212,182; Paddle Aug, 20, 1940 2,363,571 Chaffee Nov. 28, 1944 2,414,992 Wheeler Jan. 28, 1947 2,481,852 Loughlin Sept. 13, 1949 FOREIGN PATENTS Number Country Date 216,278 Switzerland Aug. 15, 1941 792,765 France Jan. 10, 1936