US2160465A - Phase modulation - Google Patents

Phase modulation Download PDF

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Publication number
US2160465A
US2160465A US637923A US63792332A US2160465A US 2160465 A US2160465 A US 2160465A US 637923 A US637923 A US 637923A US 63792332 A US63792332 A US 63792332A US 2160465 A US2160465 A US 2160465A
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tubes
phase
frequency
circuits
tube
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US637923A
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George L Usselman
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RCA Corp
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RCA Corp
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Priority claimed from US635508A external-priority patent/US2105678A/en
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Priority to US637923A priority Critical patent/US2160465A/en
Priority to GB25638/33A priority patent/GB416707A/en
Priority to DER88866D priority patent/DE706287C/de
Priority to DER88952D priority patent/DE610375C/de
Priority to US723425A priority patent/US2045973A/en
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03C—MODULATION
    • H03C3/00—Angle modulation
    • H03C3/10—Angle modulation by means of variable impedance
    • H03C3/24—Angle modulation by means of variable impedance by means of a variable resistive element, e.g. tube
    • H03C3/26—Angle modulation by means of variable impedance by means of a variable resistive element, e.g. tube comprising two elements controlled in push-pull by modulating signal

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  • This invention relates to signalling means and in particular to means whereby the characteristics ofhigh frequency oscillations other than amplitude are varied in accordance with signals 5 to be transmitted.
  • phase or frequency modulation is advantageous because it allows the transmitter to operate at full output power, whereas in amplitude modulation it is necessary to reduce the power and operate the transmitter at about one fourth of the full transmitter power output.
  • the increased signal strength gained by phase or frequency modulation is a great advantage for reducing fading and for increasing the reliability of the service.
  • the carrier frequency is impressed through phase shifting means onto the control grids of a pair of thermionic tubes which have their anodes connected in parallel to a common tank circuit and their internal impedances varied in phase opposition by the signal wave.
  • the phase modulator stage comprises two tubes having their input electrodes symmetrically connected and energized as indicated above, and a common tank circuit connected in parallel to the anodes of said pair of tubes.
  • the presentinvention relates to an improved modulating means broadly of the type referred toabove,
  • this invention relates to an improved modulating means wherein a single phase modulator stage is preceded by an amplitude modulator stage which comprises a pair of tubes having control grids connected in circuits and 5 energized at carrier frequency in phase.
  • each tube is equipped with its own separate tank circuit.
  • the phase shifting means is interposed between the' separate tank circuits and the control electrode. of the single tube in the following stage.
  • the internal impedances of the pair of tubes 15 are varied in opposite senses ⁇ by the modulating frequencies. In the present case this results in amplitude modulation of the carrier.
  • This modulated energy is then fed by way of phase shifty ing elements to the control grid of the single 20 phase modulator tube.
  • FIG. 1 illustrates a specific embodiment of the invention
  • Figures 2, 3, 4 and 5 illustrate modifications of the arrangement of Figure 1.
  • a specic embodiment of my invention is 35 shown in Figure 1.
  • gure A is a source of constant frequency oscillations, such as a crystal controlled oscillator or a long line frequency controlled oscillator.
  • the oscillator A is connected in parallel by way of blocking condensers I 40' and 3 to the control grids 2 and ll of tubes G and I-I respectively of stage C.
  • the tubes G and H are shown as the screen grid type, although three element tubes may be used. In the latter case neutralizing circuits: may be necessary.
  • the 45 anode electrodes 6 and 8 of tubes G and H respectively are connected to tank circuits M and N respectively.
  • Tank circuit M includes a variable capacity l0 and an inductance Il.
  • the tank circuit N includes a variable capacity I0 andin- 5o ductance ll'.
  • the alternating current circuits .for tubes G and H are completed by connecting the lower terminals of tank circuits M and N by way of by-passing condensers C1 to the grounded sidev of the circuit l2 supplying heating current 65 from the source K to the cathodes of the tubes.
  • the energizing circuits for anodes 6 and 8 are completed by Way of a lead I3 connecting the terminals of inductances II and I I to the source K.
  • Tank circuit M is connected through a blocking condenser O to one end of the phase retarding element L.
  • Tank circuit N is connected through a blocking condenser P to one end of the phase advancing element Q.
  • the other ends of both phase shifting elements are connected together as shown and to the grid S of tube I in stage D.
  • the alternating current input circuit of tube I is completed by way of radio frequency choking inductance I4 and by-pass condenser I5 connected between the grid S and cathode I6 of tube I.
  • the cathode I6 is maintained at stable potential by connecting one side thereof to ground G as shown.
  • the desired negative potential may be supplied to the grid S by way of choke coilv I4 and lead I'I connected with source I8.
  • the alternating current anode cathode circuit of tube I comprises the anode 26, tank circuit R, by-pass condenser ZI, and the grounded side of cathode I6.
  • the direct current anode cathode circuit of tube I comprises the anode 20, the inductance 22 of tank circuit R, a portion of the source I8, and the cathode I6.
  • Tank circuit R may be tuned to the desired frequency by a variable capacity 23 connected in parallel with inductance 22,
  • the tube I is of the screen grid type and charging potential is supplied to the screen grid electrode 24 by a lead 25 connected to a point on source I8. Any radio frequency potentials appearing on 24 are shunted around source I8 by a by-pass condenser 26.
  • the screen grid tube I may be replaced by a three-electrode tube provided proper precautions are taken to obtain stable operation thereof.
  • sources K and I 8 may be of any desirable type, such as, storage batteries, motor generator sets, or vacuum tube rectiers.
  • stage D The tank circuit R, of stage D is connected, by way of a line including blocking condenser U, to the stage E.
  • Stage E may consist of limiting devices and either frequency multipliers or amplifiers or both.
  • the last stage is connected by transmission lines V-V to the antenna F.
  • B represents a source of signal frequency of any nature.
  • the source of modulating potentials, B is connected with the primary winding 30 of asignal frequency transformer T1.
  • of this transformer is connected as shown by way of radio frequency inductances 32 and 32 to the control grids 2 and 4 of tubes G ⁇ and H respectively, as shown.
  • the inductances 32 and 32 may be replaced by resistances if desired.
  • the lower ends of inductances 32 and 32'V are connected by way of by-passing condensers 33 and 33 to the grounded lead of the cathode heating circuit I2.
  • the proper biasing potentials are applied to the control electrodes 2 and 4 by way of the secondary winding 3
  • Charging potentials for the screen grid electrodes 3.6. and 36' of tubes G and H are supplied by way of lead 31 connected to a point on potentiometer resistance P2 shunted across source K. Alternating current appearing on the grid electrodes 36, 36' is shunted around source K by by-pass condensers 38 and 38 connected as shown.
  • the oscillator A supplies equal amounts of high frequency excitation Voltage to each of the control grids 2 and 4 of tubes G and H in stage C. If there is no signal frequency being supplied to the control grids 2 and 4 from B by way of T1, this high frequency energy will be amplified equally and, if desired, multiplied in frequency in tubes G and I-I and tank circuits M and N respectively. This follows from the fact that like potentials are applied to the electrodes of 4these two tubes and also to the fact that tank circuits M and N are made to be of similar characteristics.
  • phase retarding element L and phase advancing element Q are of equal magnitude, the high frequency energy reaching the grid S of tube I in stage D, from tank circuit M and from tank circuit N, will be of equal intensity.
  • the energies will have equal phase angles, that is, one leading and the other lagging, about the average phase position.
  • the resultant phase of the excitation energy supplied to S from M and N will in this case lie midway between the phase angles of the separate energies supplied from M and N.
  • Stage D amplifies, or, if it is desired, may be adjusted to multiply the carrier frequency before it is transmitted to stage E. As I have said before, the carrier energy may be limited and multiplied in frequency or amplilied, or both, in stage E. From the last stage, ⁇ the carrier energy is transmitted through the transmission line V-V to antenna F, where it is radiated into space.
  • the Vcarrier energy produced in oscillator A is delivered in two equal parts to the grids 2 and 4 of tubes Gand H respectively in stage C.
  • protionr is amplied in amplifier G and appears in tank circuit M, while the other portion is amplified 1 irlY amplier H and appears in tank circuit N.
  • This amplification isnot constant because the amplified energies in the two amplifiers G and H are differentially modulated in amplitude so that the carrier energies delivered by the two ampliers are of the'same phase angle, but of an amplitude which varies at signal frequency and which is proportional to the signal intensity. Due to the action of the modulating transformer T1 this variation in amplitude is made opposite for each amplifier about an average value. This differentialr action will increase the power output of tubeG and tank circuit M, while the power output of tube H and tank circuit N will be decreased a like amount, or Vice versa.
  • phase deviation or shift caused by L and Q in the two high frequency energies supplied to the grid S of tube I will Vbe equal but the energies will be of unlike sense, and in this case the power supplied from Steady negative bias is tank circuitM through phase retarding element L willbe greater than the power supplied from tank circuit N through phase advancing element Q.
  • These two differentially modulated carrier energies are impressed on the grid electrode S of tube I at different phase angles because of the'action of phase shifting elements L and Q.
  • the impedance of La nd Q should be made equal so that they have equal effect on the amplitude of the carrier energiesdelivered thereby from tank circuits M and N to control grid electrode S. Itcan be seen that we now have two carrier energies of the same frequency present on the grid S of tube I and that these two carrier energies have a constant phase diierence but are of an amplitude which varies differentially about a constant total amplitude or average.
  • Tank circuit R has only one degree of freedom, that is, the carrier frequency or a desired harmonic of the carrier frequency to which the tank circuit may be tuned so that there can be but one oscillating current in the tank circuit R.
  • phase of the oscillating current in the tank circuit will be determined or controlled to a greater extent or made to shift toward that of the carrier energy having the greater amplitude.
  • the amount of the shift will be proportional to the excess energy of one part of the carrier energy over the other part of they carrier energy.
  • the amount of shift in phase of the carrier energy is limited by the value of the reactances of the phase shifting elements L and Q, as has been Vexplained before. This results in carrier energy in the tank circuit R of stage D, which will be of substantially constant amplitude but of varying phase angle.
  • the frequency of the variation of thisphase angle is the signal frequency and the degree or amount of phase swing or phase deviation is substantially proportional to the amplitude of the signal.
  • phase modulation is also controlled by the values of the phase shifting elements L and Q. If the energy in tank circuits M and N are linearly amplitude modulated in phase opposition, the phase of the energy appearing in tank circuit R of stage D will be linearly phase modulated.
  • the energy delivered from stage D may be utilized in any desired manner.
  • the energy may be amplified or multiplied in frequency and it may be radiated from the antenna F.
  • the frequency of the phase modulatedcarrier is multiplied the angle of phase modulation is increased in the same ratio.
  • Vthe modulating potentials from the source B are supplied by Way of transformer T1 in phase opposition to the ⁇ anodes 6 and 8 of tubes G and H respectively. Inthis manner anode modulation in amplitude of the carrier waves passed by tubes G and H is accomplished in the stage C..
  • the arrangement shown in Figure 3 operatesthe same as the arrangement of Figure 1. A repetition of the operationA of these novel modulating arrangements in connection with Figure 3 is thought unnecessary.
  • the arrangement ofj Figure 4. may be used.
  • the'tubes G and H are'of the three-electrode type.
  • Three-electrode tubes are used in this arrangement because, when they amplitude modulation of the carrier is accomplished by varying the anode potential, the 'three-electrode tubes give much greater response than that obtainable with the four-electrode tubes of Figure'S.
  • the capacity between the anode electrodes and'grid electrodesof the tubes G and' H may be neutralized by plate circuit neutralization.
  • TheY phase modulator of Figure 4 operates the same as the phase modulator of Figure 1.
  • high frequency oscillations from A are impressed cophasally in equal amounts onto the control electrodes of G and H respectively.
  • 'I'hese oscillations may be amplified or frequency multiplied, or both, in the tubes G and H, and in particular in the output circuits thereof.
  • the high frequency oscillations, whether amplified, frequency multiplied, or both, are differentially modulated in amplitude in stage C in accordance with the signal impressed from source B in phase opposition on the anode electrodes of tubes G and H.
  • the carrier energies from M and N which are of the same phase but of amplitude which varies at signal frequency, are fed through the phase shifting means L and Q to the control electrode S of tube I.
  • the source of oscillations A is coupled by way of blocking condensers I and 3 to points on the inductance 40 of the grid tank circuit X.
  • This tank circuit X is tuned tothe desired frequency by variable capacity 4
  • 'Ihe high frequency oscillations from tank circuit X are applied in phase opposition to the control electrodes 2 and 4 of tubes G and H.
  • phase shifting elements L and Q are fed by way of phase shifting elements L and Q to the modulator tube, as in the prior arrangements.
  • This modulation is accomplished in the tube V in the arrangement of Figure 5 and the phase modulated and amplitude modulated energy in the tank circuit R is fed by way of unit E, which may include all of the elements included in the like unit in the prior gures, to the load circuit F.
  • the tank circuits M and N should be tuned alike, that is, to the-same frequency, whether they are tuned to a fundamental or to a harmonic. In some cases it is suggested that a slight amount of mutual inductive coupling between the two circuits M and N be maintained in the proper direction to aid in keeping the two modulator tubes G and H in step. In some cases this should improve the operation of the transmitter.
  • the phase shifting elements L and Q may take the form of inductances and capacities, or any combination thereof, or may be replaced by transmission lines of the proper length. These lines may be artificial lines and may include tuning means. All that is necessary is that the desired amount of phase shift is introduced into the amplitude modulator carrier energy reaching the tube V.
  • tubes of any type known may be used to replace the tubes used in the circuits included above, which are intended to be illustrative of the invention and are not intended to limit the invention in any manner except as limited in the claims appended hereto.
  • Signalling means comprising, a source of oscillations, a modulator tube, a pair of electron discharge tubes having parallel input circuits connected to said source of oscillations means for varying the impedances of said pair of tubes in phase opposition at signal frequency, and output circuits connected through separate phase shifting means of different character to the input electrode of said modulator tube.
  • Signalling means comprising, a source of substantially constant frequency oscillations, a thermionic modulator tube, a pair of thermionic relay tubes having symmetrical input circuits and separate anode circuits, means for applying energy from said source to the input circuits of said pair of tubes in phase, and phase shifting means having different characteristics connecting each of said anode circuits to the control electrode of said modulator tube.
  • Modulating means comprising, a pair of electron discharge repeater tubes each having input and output electrodes, carrier frequency energizing circuits connected with the input electrodes of said repeater tubes, a separate tuned tank circuit connected to the output electrodes of each ⁇ of said tubes, means connected with said tubes for varying the internal impedance of said tubes in phase opposition at signal frequency, a modulator tube having an input electrode, and reactive circuits of different character connecting the input electrode of said modulator tube to each of said tank circuits.
  • a phase modulating means comprising, a pair of thermionic tubes having input circuits energized by a carrier frequency Wave and separate anode tank circuits, a modulator tube, phase changing means for connecting a point on each of said tank circuits to the control electrode of said modulator tube to excite the same by energy in phase displaced relation from said tank circuits, and a source of modulating voltages connecting the control electrodes of said pair of tubes in phase opposition.
  • Phase modulation means comprising, a pair of thermionic tubes of the screen grid type having input circuits energized by a carrier frequency Wave and separate anode tank circuits, a modulator tube, phase changing means for connecting a point on each of said tank circuits to the control electrode of said modulator tube to excite the same by energy in phase displaced relation from said tank circuits, and a source of modulating voltages connecting the screen grid electrodes of said pair of tubes in phase opposition.
  • Phase modulating means comprising, a pair of thermionic tubes having input circuits energized by a carrier frequency Wave and separate anode tank circuits, a modulator tube, phase changing means for connecting a point on each of said tank circuits to the control electrodeof said modulator tube to excite thel same by energy in jphase displaced relation from said tank circuits, and a source of modulating voltages connected to the anode' electrodes of said pair ofv tubes to vary the potential of said anodes in phase opposition.
  • 'Iransmitting means comprising a source of oscillations, a pair of thermionic tubes, means for connecting said source in phase to the control electrodes of said tubes, a separate tank circuit connected to the anode of each of said tubes, a source of modulating potentials, means for impressing the modulating potentials in phase pposition on the impedances of said tubes, a modulator tube, and separate phase shifting means connecting the control electrode of said modulator tube to each tank circuit.
  • Means for relaying and phase modulating high frequency energy comprising, a pair of electron discharge tubes having their input electrodes energized in phase by Wave energy of carrier frequency, a ⁇ modulator tube, phase retarding means for applying energy from the anode of one of said pair of tubes to the control electrode of said modulator tube, phase advancing means for applying energy from the anode of the other of saidpair of tubes to the same control electrode of said modulator tube, and means for impressing modulating potentials in phase opposition on the internal impedances of said pair of tubes.
  • a pair of electron discharge tubes means for energizing the control electrodes of said tubes substantially cophasally by wave energy of carrier frequency
  • Signalling means comprising, a source of high frequency oscillations, a pair of thermionic tubes, means for connecting the control elec-,-
  • the method of signalling which comprises the steps of, generating a constant frequency carrier Wave, producing potentials of modulating frequency, varying the amplitude of the carrier oscillations in accordance with Variations in amplitude of the modulating potentials, shifting the phase of the amplitude modulated carrier Wave before transmission into a utilizing circuit at a rate dependent upon the variation in amplitude of the carrier, the shift in phase producing a carrier energy, an undesired and desired side band energy, and controlling the amount of undesired side band energy by controlling the am- Y plitude of the modulatingpotentials used to cause nation 'with a constant frequency generator ⁇ of a pair of tubes having input electrodes symmetrically connected Vto said generator, a source Yof modulating potentials connected to said input electrodes, .and a combining tube connected through separate phase shifting elements one of ⁇ whichis-capacitive, the other of which is inductive to the anodes of ⁇ said tubes.
  • a source of oscillations a source of oscillations, a combining tube, a pair of like electron discharge Ltubes having input circuits symmetrically connected to said source of oscillations and output circuits one of which is connected through van -inductance and the Vother through a condenser to said combining tube, means associated lWith said Vpair of tubes for preventing reaction lbetween the input and output circuits thereof, and means for applying Ymodulating potentials Yto .like electrodes of saidV pair of tubes.
  • a phase modulator comprising, a pair of Ylike electron discharge tubes, means for energizing ⁇ the .control electrodes of said tubes co- ⁇ phasally by wave energy, a separate tank circuit -.connected with the anodes of each of said tubes,
  • Ymeans for yimpressing Vmodulating potentials on Athe internal ⁇ impedance of said tubes, a combining tube, a phase shifting inductance and a phase shifting condenser for separately impressing energy kfrom said tank circuits on the control electrode of said combining tube, and means for preventing the wave energy appearing in the tank circuits of said pair of tubes from react- Ying .on the Wave energy applied to the control electrodesof said pairvof tubes.
  • a source of oscillations a combining tube having input electrodes, a pair of electron discharge devices operating as frequency multipliers having input circuits symmetrically connected to said source of oscillations, said pair of discharge devices each having a separate output circuit, a reactance connecting one of said output circuits to the input electrodes of said combining tube, and a second reactance of different character connecting the other of said output circuits to said input electrodes.
  • Signaling means comprising, a pair of thermionic tubes each having an anode, a cathode and a control electrode, a source of carrier Waves, circuits connecting said carrier wave source to the control electrodes and cathodesV of each of said tubes, a separate tank circuit connected between the anode and cathode of each of said tubes, reactances in each of said tank circuits ⁇ rier waves, a source .of lmodulating potentials,
  • a circuit connecting said source of modulating potentials in phase opposition to like electrodes in said tubes .a combining tube having a cathode and a control grid, ⁇ an impedance connected between the cathode and control grid of said combining tube and phase shifting reactances of different character connecting each of said Atank circuits to the controlgrid of said combining tube.
  • thermonic modulator tube having an input electrode connected through separate phase shifting elements to the output electrodes of said iirst named tubes and a source of modulating potentials connected with like electrodes in said pair of tubes for varying the internal impedance of said tubes in phase opposition at signal frequency.
  • Transmitting means comprising, a source of oscillations, a pair of thermionic tubes, means for connecting said source of oscillations in phase opposition to the control electrodes of said tubes, va separate tank circuit connected to the anode of each of said tubes, a source of modulating potentials, means for impressing the modulating potentials in phase opposition on the internal impedance of each of said tubes, a combining tube, a positive phase shifting reactance connecting the control electrode of said combining tube to one of said tank circuits, and a negative phase shifting reactance connecting the control electrode of said combining tube to the other of said tank circuits.
  • Means for relaying and phase modulating carrier frequency energy comprising, a pair of thermionic tubes having their input electrodes energized in phase opposition by a carrier frequency Wave, a thermionic modulator tube, reactive means for applying energy from the anode of one of said tubes to a control electrode in said modulator tube, means for applying energy from the anode of the other of said tubes to a control electrode in said modulator tube, means for reversingk the phase of the energy applied by one of said means, and means for impressing modulating potentials in phase opposition on the internal impedances of said pair of tubes.
  • Transmitting means comprising, a source of oscillations, a pair of thermionic tubes, circuits connecting said source of oscillations in phase opposition to the control electrodes of said tubes, a separate tank circuit, connected to the anode Vof each of said tubes, there being appreciable coupling between said tank circuits, means for tuningv said tank circuits to a frequency which is a harmonic of the frequency of said source, a source of modulating potentials, means for impressing the modulating potentials in phase opposition on the anode electrodes of said tubes, a modulator tube, and separate phase shifting means connecting the control electrode of said modulator tube to each tank circuit.
  • Signaling means comprising, a pair of electron discharge tubes having symmetrical input circuits and symmetrical grid neutralization circuits, a separate tank circuit connected ⁇ with the anode Yof each of said tubes, one of said tank circuits being ⁇ reversed as to its voltage characteristicsv with ⁇ respect to the other Atank circuit, means for applying high frequency oscillationsA in phase opposition Yto said input circuits, means for varying oppostely the impedances of said tubes at signal frequency, a
  • 23Signaling means comprising, a source of constant frequency oscillations, a thermionic modulator tube, a pair of thermionic frequency multiplier and amplifier tubes having .a tuned input circuit, a separate anode circuit connected to each tube of said pair, a circuit for applying energy from said source of constant frequency oscillations to said input circuit and to said pair of tubes in phase opposition, means coupling the input circuit and anode circuits of said pair of tubes, means for tuning the anode circuits of said tubes ⁇ to a frequency which is a multiple of the frequency of said oscillations, means for varying the internal impedances of said pair of tubes oppositely at signal frequency, phase shifting means of different character connecting each of said anode circuits to the control electrode of said vmodulator tube, and a resistance connected between the control electrode and cathode of said modulator tube.
  • Phase modulating means comprising, a pair of thermionic amplifiers and frequency multipliers of the triode type, a tuned tank circuit connected with the input electrodes of said arnplifiers and frequency multipliers, means for energizing said tank circuit by wave energy of carrier frequency, an output circuit connected to each amplifier and frequency multiplier, means for tuning the output circuit of each of said amplifiers and frequency multipliers to a harmonic of the energizing frequency, means for insuring controlled regeneration in each of said tubes including a variable capacity connecting an output electrode of each of said tubes to an input electrode of the other of said tubes, means for varying the internal impedance of said tubes in phase opposition at signal frequency, a thermionic modulator tube having a resistance connected between its input electrodes, and phase shifting means for connecting the input electrodes of said modulator tube to each of said output circuits.
  • Modulating means comprising, a pair of thermionic tubes having input electrodes and out .put electrodes, a tuned tank circuit connected to the input electrodes of said tubes, separate tank circuits connected to the output electrodes of said tubes, capactive means for tuning said separate tank circuits to a harmonic of the frequency to which the input circuit is tuned, means for applying high frequency-oscillations to said input circuit, a capacity connected between the output electrode of each of said tubes and the input electrode of the other of said tubes to insure regeneration in said tubes, a circuit for varying the impedances of said tubes at signal frequency, and a phase modulator tube having its input electrode connected through phase shifting elements to said tank circuits.
  • a Source of oscillations of carrier wave frequency an electron discharge tube, a pair of similar tubes lhaving input circuits connected to said source of carrier frequency oscillations, output circuits connected with each of the tubes of said pair of similar tubes, a phase shifting coil connecting one of said output circuits to the input electrode of said rst named tube, a phase shifting condenser connecting the other of said output circuits to the input electrode of said rst named tube, and circuits for applying modulating potentials in phase tentials, means for modulating the amplitude of :f5
  • the oscillations generated in accordance with said signal potentials comprising a pair of differential amplitude modulator tubes connected at their inputs with the output of said generator, said modulator tubes also acting as frequency multipliers .1'0
  • a pair of tank circuits a source of signal potentials
  • means for modulating the amplitude of the oscillations produced by said oscillator in accordance with signals from said source comprising a pair of amplitude modulator tubes connected at 25 their inputs to said oscillator and at their outputs to said tank circuits, circuits connecting said source of signal potentials to like electrodes in said modulator tubes, and means for converting the energy in the output of said tubes into phase modulated oscillations comprising an additional combining tube having a control electrode connected to each of said tank circuits, and phase shifting means of different character in the connections between said control electrode and said tankv circuits.
  • a signaling means the combination of a source of high frequency oscillations, a source of signal potentials, a radiating circuit, means for modulating the amplitude of the oscillations of said high frequency source in accordance with signals from said source of signal potentials comprising an amplitude modulator and frequency multiplier connected at its input to said source of high frequency oscillations, circuits connecting said amplitude modulator and frequency multiplier to said source of signal potentials, and means for converting the resultant energy into phase modulations, said means having -an input and an output and being connected at its input through phase shifting elements to said amplitude modulator and at its output to said vradiating circuit.
  • a constant frequency oscillation generator a source of modulating potentials
  • means for modulating the oscillations generated in accordance with potentials from said source of modulating potentials comprising a pair of amplitude modulator tubes, said tubes also acting as frequency multipliers, circuits con- 50 ecting the input electrodes of said tubes to the output of said generator and connecting electrodes in said tubes to said source of signal potentials, and means for converting the resultant energy into phase modulated oscillations comprising an additional tube, phase shifting reactances of different character connecting the input electrodes of said additional tube to the outputs of each of said pair of tubes, an amplifier and frequency multiplier connected at its input '10 with the output of said additional tube, and means for neutralizing the internal capacity between electrodes in the amplitudey modulator tubes.
  • the method of signalling by means of high frequency oscillations and signal potentialsV which includes the steps of dividing the high frequency oscillatory energy into two portions, multiplying the frequency of the high frequency oscillations in each portion and simultaneously varying the amplitude of said portions in phase opposition in accordance with the signal potentials, shifting the phase of the oscillatory energy in each portion, and combining the resultant energies.
  • the method of signaling by means of carrier frequency oscillatory energy and signal p0- tentials which includes the steps of separating said oscillatory energy of carrier frequency into tw-o portions, the phases of the oscillatory energies of said portions being displaced substantially 180, differentially amplitude modulating the oscillatory energy in said portions at signal frequency, relatively shifting the phase of the differentially amplitude modulated oscillatory energy in said portions, and combining the energies in the portions to pr-oduce a resultant the phase of which is determined by the relative amounts of said portions combined.
  • Transmitting means comprising a source of oscillations, a pair of thermionic tubes, circuits connecting said source of oscillations to the control electrodes of said tubes, separate tank circuits connected to the anode of each of said tubes, there being an appreciable coupling between said tank circuits, a source of modulating potentials, means for impressing the modulating potentials in phase opposition on like electrodes of said tubes, an additional tube, and separate reactive means of different character connecting the control electrode of said additional tube to each tank circuit.
  • a pair of electron discharge tubes each having input and output electrodes, carrier wave frequency energizing circuits connected with the input electrodes of said tubes, a separate tuned tank circuit connected to the output electrodes of each of said tubes, means connected with said tubes for varying the internal impedance of said tube in phase opposition at signal frequency, a combining tube having an input electrode, a phase shifting inductance connecting the input electrode of said combining tube to one of said tank circuits, and a phase shifting condenser connecting the input electrode of said combining tube to the other of said tank circuits.
  • means for differentially amplitude modulating two portions of oscillatory energy of like frequency in accordance with signals means for simultaneously increasing the frequency of the oscillatory energy of each portion like amounts, means for relatively phase shifting the energy of said two differentialy amplitude modulated portions, and means for combining the resultants to produce a component the phase of which varies at signal frequency.
  • a method of impressing phase changes at signal frequency or wave energy comprising, dividing the energy from a source of wave energy into two branches, differentially modifying the amplitudes of the energy in the branches in accordance with signals, then subjecting the energy in one branch to a leading power factor and subjecting the energy in the other branch to a lagging power factor, then combining the energy from the two branches so that the combined wave is bf substantially constant amplitude with a varying phase.
  • a radio transmitter In an amplifier for modulating high frequency waves, a radio transmitter, two parallel branch circuits to which high frequency wave energy is fed by the transmitter, means for introducing a signal component on the high frequency energy in each branch, a capacitative reactance in the output of one branch and an inductive reactance in the output of the other branch, and ⁇ means for coupling said capacitative and inductive reactances whereby there is generated an output wave of substantially constant amplitude whose longitudinal dimensions vary about a medial point in accordance with the signal component.
  • Means for impressing phase modulations at signal frequency on carrier frequency oscillations including, a pair of thermionic tubes having their input electrodes connected ln circuits for impressing the oscillations to be modulated on the control grids of said tubes, the impressed oscillations being of like phase, means for varying the impedances of said tubes in phase opposition at signal frequency, and separate circuits connected with the output electrodes of said tubes for relatively shifting the phase of the oscillations repeated in said tubes.
  • the method of producing carrier wave energy modulated in phase at signal frequency which includes the steps of, separately modulating the amplitude of a plurality of carrier wave oscillations, of like phase and frequency, in opposite sense at signal frequency, relatively shifting the phases of the amplitude modulated 'carrier wave oscillations of like frequency, and combining the resultant energy to produce wave energy modulated in phase at signal frequency.
  • a source of oscillatory energy of carrier wave frequency an output circuit, two parallel branches each having an input to which oscillatory energy is fed from said source of oscillatory energy, means for modulating the amplitude of the oscillatory energy in eac ⁇ h branch at signal frequency, a capacitive reactance coupling one branch to said output circuit, an inductive reactance coupling the other branch to said other output circuit and means associated with said branches for preventing oscillatory energy therein and in said output circuit from reacting on said source of oscillatory energy.
  • a phase modulating system an output circuit, a source 'of modulating potentials, a source of high frequency oscillations, a pair of thermioni'c tubes having separate anode circuits coupled to said output circuit, and circuits connecting the electrodes of said tubes to said sources to apply carrier frequency waves to said tubes and phase opopsed modulating potentials to the impedances between like electrodes of said tubes, whereby the carrier frequency waves in said tubes are differentially modulated in amplitude and phase shifting means in the anode circuits of said tubes for producing relative phase shifts of the differentially amplitude modulated waves in said anode circuits.

Landscapes

  • Microwave Amplifiers (AREA)
  • Transmitters (AREA)
  • Particle Accelerators (AREA)
  • Control Of Position, Course, Altitude, Or Attitude Of Moving Bodies (AREA)
US637923A 1932-09-30 1932-10-15 Phase modulation Expired - Lifetime US2160465A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
US637923A US2160465A (en) 1932-09-30 1932-10-15 Phase modulation
GB25638/33A GB416707A (en) 1932-09-30 1933-09-15 Improvements in or relating to modulated carrier wave transmitting apparatus
DER88866D DE706287C (de) 1932-09-30 1933-09-28 Schaltung zur Phasenmodulierung einer Sendeanlage
DER88952D DE610375C (de) 1932-09-30 1933-10-12 Verfahren zur Phasenmodulation
US723425A US2045973A (en) 1932-09-30 1934-05-02 Modulation

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US635508A US2105678A (en) 1932-09-30 1932-09-30 Modulation
US637923A US2160465A (en) 1932-09-30 1932-10-15 Phase modulation
US723425A US2045973A (en) 1932-09-30 1934-05-02 Modulation

Publications (1)

Publication Number Publication Date
US2160465A true US2160465A (en) 1939-05-30

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Family Applications (2)

Application Number Title Priority Date Filing Date
US637923A Expired - Lifetime US2160465A (en) 1932-09-30 1932-10-15 Phase modulation
US723425A Expired - Lifetime US2045973A (en) 1932-09-30 1934-05-02 Modulation

Family Applications After (1)

Application Number Title Priority Date Filing Date
US723425A Expired - Lifetime US2045973A (en) 1932-09-30 1934-05-02 Modulation

Country Status (3)

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US (2) US2160465A (de)
DE (2) DE706287C (de)
GB (1) GB416707A (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2437872A (en) * 1943-02-05 1948-03-16 Mullard Radio Valve Co Ltd Phase modulator

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE882102C (de) * 1944-03-06 1953-07-06 Int Standard Electric Corp Hochfrequenzuebertragungsanlage
DE947176C (de) * 1954-07-03 1956-08-09 Telefunken Gmbh Selbsterregte Rueckkopplungsschaltung zur Erzeugung frequenzmodulierter Hochfrequenzschwingungen

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2437872A (en) * 1943-02-05 1948-03-16 Mullard Radio Valve Co Ltd Phase modulator

Also Published As

Publication number Publication date
DE610375C (de) 1935-03-13
US2045973A (en) 1936-06-30
DE706287C (de) 1941-05-22
GB416707A (en) 1934-09-19

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