US2406309A - Frequency stabilization - Google Patents

Frequency stabilization Download PDF

Info

Publication number
US2406309A
US2406309A US464380A US46438042A US2406309A US 2406309 A US2406309 A US 2406309A US 464380 A US464380 A US 464380A US 46438042 A US46438042 A US 46438042A US 2406309 A US2406309 A US 2406309A
Authority
US
United States
Prior art keywords
frequency
oscillation
voltage
value
oscillator
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US464380A
Other languages
English (en)
Inventor
Ziegler Marc
Kobilsky Manuel Julio
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hartford National Bank and Trust Co
Original Assignee
Hartford National Bank and Trust Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to FR957645D priority Critical patent/FR957645A/fr
Application filed by Hartford National Bank and Trust Co filed Critical Hartford National Bank and Trust Co
Priority to US464380A priority patent/US2406309A/en
Priority to US478705A priority patent/US2383359A/en
Application granted granted Critical
Publication of US2406309A publication Critical patent/US2406309A/en
Priority to CH264774D priority patent/CH264774A/de
Priority to DEP26531D priority patent/DE821047C/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J7/00—Automatic frequency control; Automatic scanning over a band of frequencies
    • H03J7/02—Automatic frequency control
    • H03J7/04—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant
    • H03J7/042—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant with reactance tube
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03C—MODULATION
    • H03C3/00—Angle modulation
    • H03C3/02—Details
    • H03C3/09—Modifications of modulator for regulating the mean frequency
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
    • H03D3/00—Demodulation of angle-, frequency- or phase- modulated oscillations
    • H03D3/001—Details of arrangements applicable to more than one type of frequency demodulator
    • H03D3/003—Arrangements for reducing frequency deviation, e.g. by negative frequency feedback
    • H03D3/004—Arrangements for reducing frequency deviation, e.g. by negative frequency feedback wherein the demodulated signal is used for controlling an oscillator, e.g. the local oscillator
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
    • H03D3/00—Demodulation of angle-, frequency- or phase- modulated oscillations
    • H03D3/02—Demodulation of angle-, frequency- or phase- modulated oscillations by detecting phase difference between two signals obtained from input signal
    • H03D3/04—Demodulation of angle-, frequency- or phase- modulated oscillations by detecting phase difference between two signals obtained from input signal by counting or integrating cycles of oscillations
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03L—AUTOMATIC CONTROL, STARTING, SYNCHRONISATION OR STABILISATION OF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES
    • H03L7/00—Automatic control of frequency or phase; Synchronisation
    • H03L7/02—Automatic control of frequency or phase; Synchronisation using a frequency discriminator comprising a passive frequency-determining element

Definitions

  • the present invention relates to frequency sta bilization and more p'articularly'to thestabilization at a desired value of the frequency of an oscillator.
  • the frequency of the oscillator itself does not vary, and the mean frequency of the'output signal remains equal to it.
  • control of the circuit may be either mechanical, as by means of variable condensers, moving cores and the like, or electrical, as by means of magnetic saturation,
  • the controlling magnitude may be obtained in one of two general ways, namely, either by operating on the basis of the phase difference between the oscillation to be controlled and a pilot oscillation, or by obtaining it from a frequency responsive device which measures the frequency difference between said oscillations.
  • the first way leads to a synchronization of the two oscillations andto a resultant frequency which is rigorouslyequal to that of the pilot.
  • the classical phasemeasuring methods are limited however to phase differences smaller than 1r/2 which is a given limitation.
  • the second method gives rise merely to a reduction of the frequency, though this reduction can generally be as large as desired.
  • the ,present invention is more particularly concerned with the frequency reduction methods of stabilization. r
  • the response of the common discriminator circuits depend either on the amplitude of the applied signal and on the value of a compensating voltage, or on the-correct balance of a symmetric detector arrangement, all of which factors are possible causes of drift from the exact adjustment.
  • the method of the present invention and the [devices for the realization thereof while having the same basic idea as other frequency stabilizing arrangements, namely, to measure the frequency diiference between the oscillation to be stabilized or controlled and a pilot oscillation and to use the magnitude so obtained for automatically reducing the frequency difference as much as possible, utilizes, in contradistinction to the prior art, a compensated frequency meter the outputof which is zero for a predetermined frequency independently of the battery tension applied.
  • the present invention dispenses with the use of a symmetric discriminator design comprising selective inductance and capacity cirlong as the variation.
  • the condenser is each time charged tothe same potential and Preferably the mixer 12 includes a convenient output filter from which the signal of frequency difference resulting from the mixing of the oscillator and pilot outputs is obtained. 7
  • the frequency drift of the oscillator when connected to the correcting link is approximately A times smaller than the frequency ber of periods, is proportional to the number-0f drif t t h n A being acenstant of the arrangement equal to th product of the sensitivity lc-of the frequency meter it in voltsper kcJand' the influenced ofthereactance tube 22' in kc. per volt.
  • the output of the" frequency meter Since for successful operation of" the novel method of frequency stabilization the output of the" frequency meter must be properly compenthe longest period of the frequencies passed during therexcursion, and that, even if the frequency modulation has a period of the same order as or even smaller than said longest period, the averagegvalue of the output current, taken over a long time, will still be proportional to the central frequency.
  • I i Fig. l is a block diagram illustrating the method offrequency stabilization of the present in' vention
  • I I Fig. 2' is a diagram illustrating a frequency modulated transmitter embodying frequency stabilization according to the present invention.
  • the basic idea underlying the present method is to measure the frequency difference between the oscillation to be stabilized and the oscillation of apilot, and it is therefore obvious that the frequency difference which is to be the direct cause of the controlling action to be applied to the oscillator, must be Within the working range, an univocal function of the oscillator frequency.
  • the present invention provides means for compensating this effect.
  • the output current of the frequency'meter fore proportional to the frequency, to. the capacity of the condenser, to thevoltageup to whichthe condenser has been charged and to the resistance in H If now through which the current is now;
  • the frequency meter as shown, likewise comprises a condenser C and an outputresistance r, and is preferably provided with an output filtercomprising resistances 28 and .36 and condensers 32 and 34-. o
  • the oscillations present in the output of the mixerstage lZa are applied to the grid of the valve'2 During those half periods of the oscillationior which the ridrispositive'with rfi pecttothe cathode-ofthe valve. the-latter willbeconductive,
  • capacitor C will be discharged through diode Illl, resistor q and the external circuit including battery B, anoderesistor I04 and potentiometer 26.
  • Resistors I02 and H13 included in the grid circult, of valve 24, are designed to transform the oscillation generated in the output circuit of the mixer stage [2a into a square wave. Across resistor 1' there is generated a discharge capacitor 0 every time the control grid of the valve 24 is positive with respect to the cathode of this valve, so that for each period of the oscillation applied to valve 24, an electrical impulse is obtained in such a form that the mean value of the tension developed across resistor r is proportional to the frequency of the oscillation applied to the control grid of valve 24.
  • the tension so developed across the resistor r is compensated to zero for a given value of the frequency of the oscillation applied to the grid of valve 24 by means of the compensating tension AB so that the resulting voltage assumes positive and negative values in proportion to the sense and amount of deviation of the frequency'of the oscillation from the given value.
  • the low pass filter following resistor r and constituted by resistors 28 and 30 and condensers 32 and 34 is adapted to suppress the alternating components in the mean voltage developed across the resistor r.
  • said desired frequency can be adjusted to a predetermined value by varying either the potentiometer relation A, the output resistance or the capacity of the frequency meter, which is a very interesting feature.
  • impulse of Y factors can each be made adjustable with all the precision required and may present a high degree of constancy. For this reason, and
  • the desired frequency can be changed, by choosing, for exampleanother position of the potentiometer which determines the fractional compensating voltage.
  • the potentiometer which may be of the continuously or stepby-step variable type, may be calibrated in kilocycles for adjustment. Alternativelythe output resistance or the .capacitymay be made 31d? justable, and in the latter event, the condenser of the frequency meter would be made variable or comprise a variable portion, as indicated by the arrowin broken lines in Fig. 2.
  • both of the oscillators is frequency modulated, stabilization is also possible, provided that care is takenv that the predetermined frequency difference is sufiiciently greater than the sum of the maximum excursions of the oscillators for the reasons hereinabove set forth.
  • the frequency stabilization method of the present. invention may also be applied to frequency modulated transmission, and an embodiment of such application is shown in Fig. 2.
  • the transmitteriantenna 36 is connected through a'power output section 38, a driver or doubler 40 and a separator 42 to an oscillator l0a, which is connected to the mixer
  • a reactance tube 2211 which in the present instance acts both as stabilizer. and. as modulator.
  • the frequency meter arrangement maintains the central frequency constant, the output of the oscillator is also'frequency modulated by super-' Thus while I oscillator. Again, itis 1 bility. of the central tically only :upon the cillator used. In general,"the complete stabiliz- I, ingarrangement does n 3 single adjustment the desired frequency,
  • ot require more than a .in'orderto adapt it to work at and a change of the value of only one element makes it. possible to stabilize the oscillator around different well-defined fre-' quencies, a feature which may have many "applications in radio communication.
  • the number "of f tubesand parts is relatively small and there is i "n' their assembly. More nothing very critical over, critical elements, such as a tube or a source of tension, may, as 'can'be shown, have variations aslarge 'as 10% without affecting the validity of the results.
  • stabilizing arrangement does not use any tuned circuits. Hence it can be utilized at any "frequency, and may be assembled and marketed as a universal frequency modulation and stabilization unit. Inclusion of the quartz pilot and of the oscillator gives a frequency modulation transmitting unit adapted to be directly connected to a frequency modulation transmitter.
  • V The method of detecting frequency deviae oscillation about a prededirect current source it should be noted that the quency of saidjo'scil lation and to :said voltage,
  • said electrical oscillation connected in series with said source, comprising thesteps of generating electrical impulses for each period of said oscillation having an area substantially proportional to the voltage of said source and a durathe periods of the-highest fretion smaller than quency to be detected, integrating said'impulses to obtain an electrical quantity substantially proportional to the frequency of said oscillation and to said voltage, and simultaneously injecting another electrical quantity derived from said source in, opposition to said first an output quantity which is compensated to zero independently of variations of said voltage at 'a frequency value of the oscillation equal to t'he said predetermined frequency value and the polarity and value of which are proportional.
  • a compensated frequency discriminator for of an electrical frequency comprising a circuit containing a source of direct current and a resistance, "means for interrupting the current in said circuit in synchronism'jwith half-waves of like sign of'said oscillation to obtain voltage ipul'sations a'crosssa'id resistance, means for transforming said Voltage pulsations into electrical impulses of like sign having an area substantiallyproportional to the voltage of said source, an amplitude independent of said oscillation and a duration smaller than the half-periods of the highest frequency to be de tected, means to integrate said impulses to obtain a potential substantially proportional to the frequency of said oscillation and to the voltage of to connect a fraction of said voltage in opposition to said pote'ntial'to produce an output potential which is compensated to zero independently of voltag variations in said direct current source at frequency values of the oscillation equal to the said predetermined mean frequency value and the which are prcportionalto the deviations of said electrical oscillation from the predetermined frequ ency
  • a compensated frequency discriminator for detecting frequency deviations of an, electrical oscillation varying about a predetermined mean frequency, comprisingv a thermionic tube having a tov apply said oscillation to said control electrode to produce voltage pulsation across said resistance in synchronism with half-waves of like sign detected comprising a condenser ode electrodes, and a load of said oscillation, means having an.
  • a compensated frequency discriminator in which the condenser is adjustable and varies the frequency at which the said compensated output potential is zero.
  • a frequency stabilizing system means for generating a main oscillation the frequency of which is to be maintained at a predetermined value, frequency adjusting means coupled to said generating means, means for generating a pilot oscillation differing from said main oscillation by a predetermined frequency, means for mixing said pilot and said main oscillations to produce a difference oscillation, a circuit including a direct current source and a resistance, means for interrupting the current in said circuit in synchronism with the half-wave of like sign a of said difference oscillation to produce voltage pulsations across said resistance, means for transforming said voltage pulsations into electrical impulses of like sign having an area substantially proportional to the voltage of said source, an amplitude independent on said oscillation and a duration smaller than the half-periods of the highest frequency of said difference oscillation, means to integrate said impulses to obtain a potential substantially proportional to the frequency of said difference oscillation and to said voltage, means to connect said integrating means to said frequency adjusting means to maintain said main oscillation at said predetermined frequency value,
  • a frequency stabilizing system in which the relation between said voltage fraction and said potential is adjustable, and the frequency at which the main oscillation is stabilized is variable before and during operation.
  • means for generating an electrical oscillation the mean frequency of which is to be stabilized at a desired the frequency of a pilot oscillation generated in said frequency modulation system frequency adjusting means coupled to said main oscillation generating means, means for mixing said main and said pilot oscillations to obtain a difference oscillation, a circuit including a direct current source and a resistance, means to interrupt the current in said circuit in synchronism with half-waves of like sign of said difference oscillation to produce voltage pulsations across said resistance, means for transforming said voltage pulsations into electrical impulses of like sign having an area substantiall proportional to the voltage of said source, an amplitude independent of said oscillation and a duration smaller than the half-periods of the highest frequency of said difference oscillation, means to integrate said impulses to produce a potential substantially proportional to the frequency of said difference oscillation and to said voltage, means to inject a fraction of the voltage of the direct current source in opposition to the said potential to produce an output voltage compensated to zero independently of voltage variations in
  • a main oscillator the frequency of which may vary about an adjustable stabilized value differing by a predetermined amount from the frequency of a crystal controlled pilot oscillator, means for radiatring the energy of said main oscillation, means for adjusting the frequency of the main oscillator, means for mixing said main and said pilot osoillations to produce a difference oscillation, a thermionic tub-e having a control electrode, an anode and a cathode, a resistance and a direct current source seriall connected between the anode and cathode, a potentiometer connected in shunt with said direct current source, means to appl said difference oscillation to said control electrode to produce voltage pulsations across said resistance in synchronism with half waves of like sign of said difference oscillation, means to transform said voltage pulsations into electrical impulses of like sign having an area substantially proportional to the voltage of said source, an amplitude independent of said difference oscillation and a duration smaller than the half periods of the difference oscillation;

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Superheterodyne Receivers (AREA)
  • Stabilization Of Oscillater, Synchronisation, Frequency Synthesizers (AREA)
  • Oscillators With Electromechanical Resonators (AREA)
US464380A 1942-11-03 1942-11-03 Frequency stabilization Expired - Lifetime US2406309A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
FR957645D FR957645A (xx) 1942-11-03
US464380A US2406309A (en) 1942-11-03 1942-11-03 Frequency stabilization
US478705A US2383359A (en) 1942-11-03 1943-03-10 Frequency modulation receiver
CH264774D CH264774A (de) 1942-11-03 1947-08-07 Schaltung zur Erzeugung einer Spannung, die ein Mass der Frequenz einer Hochfrequenzschwingung ist.
DEP26531D DE821047C (de) 1942-11-03 1948-12-24 Schaltung zur Erzeugung einer Spannung, die ein Mass fuer die Frequenz einer Hochfrequenzschwingung ist

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US464380A US2406309A (en) 1942-11-03 1942-11-03 Frequency stabilization
US478705A US2383359A (en) 1942-11-03 1943-03-10 Frequency modulation receiver

Publications (1)

Publication Number Publication Date
US2406309A true US2406309A (en) 1946-08-20

Family

ID=27040960

Family Applications (2)

Application Number Title Priority Date Filing Date
US464380A Expired - Lifetime US2406309A (en) 1942-11-03 1942-11-03 Frequency stabilization
US478705A Expired - Lifetime US2383359A (en) 1942-11-03 1943-03-10 Frequency modulation receiver

Family Applications After (1)

Application Number Title Priority Date Filing Date
US478705A Expired - Lifetime US2383359A (en) 1942-11-03 1943-03-10 Frequency modulation receiver

Country Status (4)

Country Link
US (2) US2406309A (xx)
CH (1) CH264774A (xx)
DE (1) DE821047C (xx)
FR (1) FR957645A (xx)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2473853A (en) * 1946-01-22 1949-06-21 Westinghouse Electric Corp Frequency control system
US2526353A (en) * 1946-11-15 1950-10-17 Rca Corp Stabilized low-frequency oscillator
US2545296A (en) * 1946-02-20 1951-03-13 Mittelmann Eugene Constant frequency control for high-frequency heating apparatus
US2582768A (en) * 1944-07-19 1952-01-15 Csf Frequency transposing device
US2600288A (en) * 1943-10-14 1952-06-10 Hartford Nat Bank & Trust Co Frequency stabilizing apparatus
US2617037A (en) * 1948-03-27 1952-11-04 Hartford Nat Bank & Trust Co Automatic frequency control circuit
US2624006A (en) * 1948-04-15 1952-12-30 Hartford Nat Bank & Trust Co Automatic frequency control circuit
US2724778A (en) * 1946-03-07 1955-11-22 Jasik Henry Electrical generating device
US2725476A (en) * 1950-05-22 1955-11-29 Hartford Nat Bank & Trust Co Phase stabilising device
US2774872A (en) * 1952-12-17 1956-12-18 Bell Telephone Labor Inc Phase shifting circuit
US2831632A (en) * 1950-11-04 1958-04-22 Westinghouse Electric Corp Electronic speed controlling apparatus
US3078752A (en) * 1951-12-26 1963-02-26 Rca Corp Circuit for simulating vibrato effect by amplitude modulation of tone by sawtooth waveform
US20140158268A1 (en) * 2011-07-27 2014-06-12 Galileo Wheel Ltd. Tire for surface vehicle

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2541066A (en) * 1943-11-24 1951-02-13 Sperry Corp Object detecting and warning system and method
US2510906A (en) * 1945-03-24 1950-06-06 Avco Mfg Corp Frequency modulation receiver
NL136716C (xx) * 1946-12-10
US3084327A (en) * 1959-05-11 1963-04-02 Bell Telephone Labor Inc High efficiency frequency modulation system for television and speech signals
NL277424A (xx) * 1961-04-25
NL179435C (nl) * 1977-10-26 1986-09-01 Philips Nv Ontvanger met een frequentiesynthese-schakeling.

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2600288A (en) * 1943-10-14 1952-06-10 Hartford Nat Bank & Trust Co Frequency stabilizing apparatus
US2582768A (en) * 1944-07-19 1952-01-15 Csf Frequency transposing device
US2473853A (en) * 1946-01-22 1949-06-21 Westinghouse Electric Corp Frequency control system
US2545296A (en) * 1946-02-20 1951-03-13 Mittelmann Eugene Constant frequency control for high-frequency heating apparatus
US2724778A (en) * 1946-03-07 1955-11-22 Jasik Henry Electrical generating device
US2526353A (en) * 1946-11-15 1950-10-17 Rca Corp Stabilized low-frequency oscillator
US2617037A (en) * 1948-03-27 1952-11-04 Hartford Nat Bank & Trust Co Automatic frequency control circuit
US2624006A (en) * 1948-04-15 1952-12-30 Hartford Nat Bank & Trust Co Automatic frequency control circuit
US2725476A (en) * 1950-05-22 1955-11-29 Hartford Nat Bank & Trust Co Phase stabilising device
US2831632A (en) * 1950-11-04 1958-04-22 Westinghouse Electric Corp Electronic speed controlling apparatus
US3078752A (en) * 1951-12-26 1963-02-26 Rca Corp Circuit for simulating vibrato effect by amplitude modulation of tone by sawtooth waveform
US2774872A (en) * 1952-12-17 1956-12-18 Bell Telephone Labor Inc Phase shifting circuit
US20140158268A1 (en) * 2011-07-27 2014-06-12 Galileo Wheel Ltd. Tire for surface vehicle

Also Published As

Publication number Publication date
CH264774A (de) 1949-10-31
FR957645A (xx) 1950-02-23
US2383359A (en) 1945-08-21
DE821047C (de) 1952-01-07

Similar Documents

Publication Publication Date Title
US2406309A (en) Frequency stabilization
US2419527A (en) Radio frequency transmitter monitoring system and method
US3068427A (en) Frequency modulator including voltage sensitive capacitors for changing the effective capacitance and inductance of an oscillator circuit
US2250104A (en) Frequency regulation
US2574482A (en) Automatic frequency and phase control system
US2540333A (en) Device for automatic frequency correction
US2588551A (en) Frequency modulation
US2786140A (en) Apparatus for frequency interpolation
US1788533A (en) Frequency-control system
US2456763A (en) Frequency stabilization
US2425981A (en) Balanced frequency discriminator
US2676262A (en) Automatic frequency control system for oscillators
US2764681A (en) Frequency stabilized and controlled oscillatory system
US2584850A (en) Frequency-and voltage-stabilized oscillator
US2486265A (en) Variable frequency oscillator
US2478023A (en) Frequency monitoring system
US3349343A (en) Wide band frequency modulator, of the solid state type, with linear characteritics
US2676263A (en) Impulse generator
US2526353A (en) Stabilized low-frequency oscillator
US2600288A (en) Frequency stabilizing apparatus
US1455768A (en) Wireless receiving system
US2507317A (en) Method and apparatus for synchronizing oscillators
US2596227A (en) Frequency-modulated oscillator
US3048796A (en) Broadband diode fm modulator
US3075157A (en) Automatic rest frequency control for pulsed frequency modulated oscillator