US2842742A - Modulated beam-type electron tube apparatus - Google Patents

Modulated beam-type electron tube apparatus Download PDF

Info

Publication number
US2842742A
US2842742A US426530A US42653054A US2842742A US 2842742 A US2842742 A US 2842742A US 426530 A US426530 A US 426530A US 42653054 A US42653054 A US 42653054A US 2842742 A US2842742 A US 2842742A
Authority
US
United States
Prior art keywords
anode
cathode
modulating
tube
main
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
US426530A
Other languages
English (en)
Inventor
Donald H Preist
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.)
Varian Medical Systems Inc
Original Assignee
Eitel Mccullough Inc
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
Application filed by Eitel Mccullough Inc filed Critical Eitel Mccullough Inc
Priority to US426530A priority Critical patent/US2842742A/en
Priority to GB11106/55A priority patent/GB794334A/en
Priority to FR1132407D priority patent/FR1132407A/fr
Priority to CH336908D priority patent/CH336908A/fr
Application granted granted Critical
Publication of US2842742A publication Critical patent/US2842742A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J25/00—Transit-time tubes, e.g. klystrons, travelling-wave tubes, magnetrons
    • H01J25/02—Tubes with electron stream modulated in velocity or density in a modulator zone and thereafter giving up energy in an inducing zone, the zones being associated with one or more resonators
    • H01J25/10—Klystrons, i.e. tubes having two or more resonators, without reflection of the electron stream, and in which the stream is modulated mainly by velocity in the zone of the input resonator
    • H01J25/12—Klystrons, i.e. tubes having two or more resonators, without reflection of the electron stream, and in which the stream is modulated mainly by velocity in the zone of the input resonator with pencil-like electron stream in the axis of the resonators
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/72—Copper
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/0215—Coating
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/024—Multiple impregnation or coating

Definitions

  • the principal object of my invention is' to provide a tube in which the beam may be modulated in an improved manner.
  • Another object is to provide a tube wherein a relatively high power beam may be modulated with modulator.
  • Still another object is to provide such a tube which is adapted for either pulse modulation or modulation by sinusoidal or complex waves.
  • Another object is to provide a beam-type tube, such as a klystron, operable as an eificient R. F. amplifier adapted for amplitude modulation of continuous waves and delivering a C. W. carrier capable of one hundred percent amplitude modulation.
  • a beam-type tube such as a klystron
  • a still further object of my invention is to provide a tube of the character described which is of simple construction and in which the associated circuitry for modulation purposm is also simplified.
  • Figure 1 is an axial sectional view, partly in section and partly in elevation, showing my improvements incorporated in a klystron amplifier.
  • Figure 2 is an elevational view of the tube with associated circuitry for pulse modulation
  • Figure 3 is a similar view with the tube connected for amplitude modulation of a C. W. carrier.
  • an electron beam from a cathode passes through an anode and thence into the main body of the tube, such anode being connected to the body and operated at some positive potential with respect to the cathode, which potential is generally referred to as the main beam voltage.
  • my improved tube structure there are two anodes; a main anode connected to the body of the tube and a modulating anode interposed between and insulated from the cathode and the first mentioned anode.
  • the main body of the tube may be any suitable structure adapted for interaction with the beam, such as a klystron or a traveling wave structure, a klystron structure with resonant cavities being preferred as hereinafter described.
  • I provide a suitable cathode 2 supported by a stem structure 3. Electrons from the cathode are focused into a circular beam by a suitable focusing electrode 4, which beam is adapted to pass through a pair of spaced apertured anodes 6 and 7. A cylinder 8 of insulating material is provided between the main anode 6 and modulating anode 7, and another ina low power 7 7 2,842,742 Patented July 8, 1958 sulating cylinder 9 is provided between the modulating anode and the cathode structure. By this arrangement the modulating anode 7 floats electrically free between the cathode and main anode 6.
  • Anodes 6 and 7 are of metal and have terminal portions exposed externally of the envelope. Insulating cylinders 8 and 9 form wall portions of the evacuated envelope, the envelope of the entire tube being preferably of elongated cylindrical shape.
  • the anodes preferably have. tubular projections 11 and 12 at the apertures separated by a gap 13, more about which will be said later. 7
  • the beam emerging from anode 6 then passes into the main body of the tube which is preferably a three-cavity klystron amplifier comprising a drift tube terminating at a collector assembly 14.
  • the drift tube is made up of tubular metal sections 19, 20, 21 and 22 having gaps therebetween. These gaps are bridged by cavity resonators generally designated at 23, 24 and 25.
  • the cavity resonators may be completely integral with the tube, I prefer to incorporate insulating walls 26 so that portions 27 of the resonators may be applied externally to the evacuated envelope.
  • These external resonator portions may be simple metal boxes engaging the resonator walls on the tube envelope. This permits putting the tuning mechanism 30 in the external portions, which is a great convenience because it is out of the vacuum.
  • Another important advantage of the external resonator structure is that it will accommodate tuning mechanisms which cover a wide frequency range, which is not easily possible if the tuning mechanism is incorporated as a part of the vacuum system.
  • Suitable magnetic means is also provided for confining the electron beam to a path axially of the envelope, which means may comprise simple magnet coils disposed about the envelope in accordance with conventional practice.
  • the insulating walls 26 are preferably ceramic cylinders sealed by flange 28 to metal disks 29 which in turn are secured to the metal drift tube sections at brazes 31. Disks 29 thus form the end walls of those resonator portions which are part of the envelope structure. With the metal boxes 27 in place the drift tubes are all electrically connected together, as will be readily appreciated.
  • Collector assembly 14 is preferably made up of a cupsh-aped metal collector electrode 32 preferably isolated from the body of the tube by an insulating wall cylinder 33, also of ceramic, sealed between supporting disks 34. Suitable heat removal means such as finned cooler 36 is provided about the collector.
  • the collector electrode also preferably carries an exhaust tubulation 37.
  • the main anode 6 is mounted directly on drift tube section 19 of the main tube body.
  • This anode is preferably a simple disk-shaped apertured metal piece brazed at 39 to section 19.
  • the tapered end of section 19 provides the tubularprojection 11 at the anode aperture.
  • Modulating anode 7 is preferably a cup-shaped metal piece surrounding cathode 2 with an apertured head end facing anode 6.
  • a tapered tubular section brazed at 41 to apertured anode 7 provides the projection 12 which is separated from the projecting end of the drift tube by gap 13.
  • the apertured anodes are thus coaxially aligned with the cathode and with the drift tube of the main body.
  • the spacing of main anode 6 from the cathode, together with the shielding provided by interposed anode 7, is such that the electrostatic field set up simply by a positive potential on anode 6 does not reach into the surface. of the cathode.
  • Such D. C. voltage on anode 6 is themain. beam voltage, V applied to the drift tube of the klystron. Therefore, under conditions of zero potential on anode 7, the beam is cut off.
  • positive potential is added to modulating anode 7, the electrostatic field is reinforced to a point where it reaches the cathode surface and starts electron current to flow down the beam.
  • Such beam current varies with the voltage on anode 7.
  • the modulating anode 7 acts like a valve for controlling the current density of the beam. Since the voltage V on main anode 6 is a constant, however, the final velocity of the electrons leaving anode 6 and entering the drift tube is a constant.
  • anodes 6 and 7 adjacent to the cathode and in the structural arrangement shown is important for several reasons.
  • Another reason is that the beam can be initially focused by electrode 4 through the first aperture at anode 7 with few if any electrons landing on the modulating anode. Consequently, the modulating anode draws negligible current and consumes little or no power. It therefore operates as a highly efficient valve device for controlling the beam current.
  • the main body of the tube functions in the same manner as the radio-frequency portion of a simple klystron amplifier.
  • R. F. driving power is fed into the first resonator 23 and R. F. output power is taken from the third resonator 25, the interaction with the beam involving bunching and debunching of the electrons in accordance with the well known principle of klystron amplifier operation. Since this part of the tube is thus operating as a simple klystron amplifier (without modulation on the R. F. driving voltage), it is seen that the R. F. drive may be set to give optimum performance and efiiciency of the radio-frequency portion of the tube.
  • the modulating anode 7 is adapted to operate at a varying potential with respect to the cathode for varying the beam current.
  • a pulse modulator P providing a positive pulse of desired shape is connected between the cathode and anode 7, so that the pulse voltage is applied to the modulating anode.
  • the voltage on the modulating anode periodically rises and falls to zero, and the beam current accordingly builds up from cut-off to some maximum value in a similar periodic fashion. This is reflected in the output as pulse R. F. power.
  • pulse modulator P any other suitable modulator may be inserted at this point for modulating the beam by sinusoidal or complex waves, as will be readily understood by those skilled in the art.
  • the modulating anode is adapted to operate at some steady potential with respect to the cathode to establish a certain value of beam current and is also adapted to operate at a varying potential to vary the beam current about such value.
  • This circuitry therefore includes a D. C. source V between the cathode and anode 7 which puts a steady positive potential on the modulating anode, the voltage V being preferably about half that of the main beam voltage V The steady voltage V thus establishes a certain value of beam current which sets the carrier level.
  • a suitable modulating device M which may be a simple transformer, is placed in series with the supply V
  • the modulation may be of any suitable wave shape, and, when superimposed on V the amplitude of the beam current will vary accordingly. This is then reflected in amplitude modulation of the R. F. output.
  • An efficient high level amplitude modulated R. F. amplifier is thus provided delivering a carrier capable of 100% modulation.
  • My improved modulating structure in a klystron amplifier having externally tuned resonators is very versatile in practical applications because it has the modulation features in a tube which also tunes over a wide frequency range.
  • a modulating circuit including a klystron comprising an elongated evacuated envelope, a cathode at one end of the envelope for initiating an electron beam, cavity resonators having metal end walls spaced along the envelope axis and forming portions of said envelope, metal drift tube sections connected to said resonator end walls and providing intermediate wall portions of the evacuated envelope, one of the drift tube sections extending towards the cathode and forming a reduced neck portion between a first of the resonators and the cathode end of the envelope, a main anode mounted on the electron receiving end of the last mentioned drift tube section, an apertured modulating anode interposed between the cathode and main anode, and modulating means connected to said modulating anode.
  • a modulating circuit including a klystron comprising an elongated evacuated envelope, a cathode at one end of the envelope for initiating an electron beam, cavity resonators having metal end walls spaced along the envelope axis and forming portions of said envelope, metal drift tube sections connected to said resonator end walls and providing intermediate wall portions of the evacuated envelope, one of the drift tube sections extending towards the cathode and forming a reduced neck portion between a first of the resonators and the cathode end of the envelope, the electron receiving end of the last mentioned drift tube section being spaced from the cathode, a main anode mounted on said re-.
  • a modulating circuit including a klystron comprising an elongated evacuated envelope, a cathode at one end of the envelope for initiating an electron beam, cavity resonators having metal end walls spaced along the envelope axis and forming portions of said envelope, metal drift tube sections connected to said resonator end walls and providing intermediate wall portions of the evacuated envelope, one of the drift tube sections extend ing towards the cathode and forming a reduced neck portion between a first of the resonators and the cathode end of the envelope, the electron receiving end of the last mentioned drift tube section being spaced from the cathode, a main anode mounted on said receiving end, an apertured modulating anode interposed between the cathode and main anode, the distance between the modulating anode and the electron receiving end of the last mentioned drift tube section being less than the length of said last mentioned section and means including said modulating anode for modulating said beam priorto its entry into the first of the cavity resonators.
  • a modulating circuit including a klystron comprising an elongated evacuated envelope, a cathode at one end of the envelope for initiating an electron beam, cavity resonators having metal end walls spaced along the envelope axis and forming ortions of said envelope, metal drift tube sections connected to said resonator end walls and providing intermediate wall portions of the evacuated envelope, one of the drift tube sections extending towards the cathode and forming a reduced neck portion between a first of the resonators and the cathode end of the enve lope, the electron receiving end of the last mentioned drift tube section being spaced from the cathode, a main anode mounted on said receiving end, an apertured modulating anode interposed between the cathode and main anode, the distance between the modulating anode and the electron receiving end of the last mentioned drift tube section being less than the length of said last mentioned section, a focusing electrode adjacent the cathode and spaced from the modulating anode for directing said beam through the
  • a beam tube having a main body section. a cathode spaced from said body section, a main anode between said cathode and said body section and having an aperture therethrough opening into said body section, a modulating anode between said cathode and said main anode and having an aperture therethrough in alignment with said aperture of said main anode, and a focussing electrode adjacent said cathode, said method comprising the steps of forming the electrons emitted'by said cathode into a beam which will pass through the apertures of said modulating anode and said main anode by means of said focussing electrode, applying a constant positive voltage to said main anode with respect to said cathode to accelerate electrons emitted by said cathode, and applying a varying voltage to said modulating anode to control the quantity of electrons in said beam.
  • a beam tube comprising a main body section, a cathode spaced from said body section, a main anode positioned between said cathode and said body section and having an aperture therethrough aligned with said body section and said cathode, a modulating anode interposed between said main anode and said cathode and having an aperture therethrough in alignment with said aperture of said main anode, with a circuit comprising a first power source connected between said cathode and said main anode and supplying a constant positive voltage to said main anode with respect to said cathode, and a second power source connected to said modulating anode and supplying a varying potential to said modulating anode with respect to said cathode.
  • a klystron comprising an elongated evacuated envelope, a drift tube extending axially of the envelope, cavity resonators disposed along the drift tube, a cathode, an apertured main anode spaced from the cathode and connected to the electron receiving end of the drift tube, an apertured modulating anode interposed between said cathode and said main anode, and a tubular focussing electrode surrounding said cathode, with a circuit comprising a first power source connected between said cathode and said main anode and supplying a constant positive voltage to said main anode with respect to said cathode, a second power source sup plying a constant positive voltage, and a third power source supplying a varying voltage, said second and said third power sources being connected in series to said modulating anode whereby said modulating anode is maintained at a voltage varyingabout a positive value with respect to said cathode.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Microwave Tubes (AREA)
US426530A 1954-04-29 1954-04-29 Modulated beam-type electron tube apparatus Expired - Lifetime US2842742A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US426530A US2842742A (en) 1954-04-29 1954-04-29 Modulated beam-type electron tube apparatus
GB11106/55A GB794334A (en) 1954-04-29 1955-04-18 Beam type electron tube apparatus
FR1132407D FR1132407A (fr) 1954-04-29 1955-04-26 Tube à faisceau électronique pour hyperfréquences
CH336908D CH336908A (fr) 1954-04-29 1955-04-28 Circuit comprenant un tube à faisceau électronique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US426530A US2842742A (en) 1954-04-29 1954-04-29 Modulated beam-type electron tube apparatus

Publications (1)

Publication Number Publication Date
US2842742A true US2842742A (en) 1958-07-08

Family

ID=47989424

Family Applications (1)

Application Number Title Priority Date Filing Date
US426530A Expired - Lifetime US2842742A (en) 1954-04-29 1954-04-29 Modulated beam-type electron tube apparatus

Country Status (4)

Country Link
US (1) US2842742A (fr)
CH (1) CH336908A (fr)
FR (1) FR1132407A (fr)
GB (1) GB794334A (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3295066A (en) * 1962-07-05 1966-12-27 Continental Electronics Mfg Multiple modulating anode beam type electron tube and modulating circuit
US3334262A (en) * 1963-12-23 1967-08-01 Varian Associates High frequency velocity modulation electron discharge devices having replaceable beam forming and projecting assemblies
US3801854A (en) * 1972-08-24 1974-04-02 Varian Associates Modulator circuit for high power linear beam tube
US4611149A (en) * 1984-11-07 1986-09-09 Varian Associates, Inc. Beam tube with density plus velocity modulation

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1295099B (de) * 1960-03-10 1969-05-14 Siemens Ag Elektronenstrahlerzeugungssystem fuer Laufzeitroehren

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2409608A (en) * 1941-09-24 1946-10-22 Bell Telephone Labor Inc Ultra high frequency detector
US2409644A (en) * 1941-04-11 1946-10-22 Bell Telephone Labor Inc Electron discharge apparatus
GB584452A (en) * 1943-07-09 1947-01-15 Western Electric Co Improvements in pulsing arrangements for electron discharge devices
US2442662A (en) * 1942-04-15 1948-06-01 Bell Telephone Labor Inc High-frequency translating apparatus
US2556978A (en) * 1948-10-07 1951-06-12 Bell Telephone Labor Inc Linear accelerator for charged particles
US2758245A (en) * 1950-12-14 1956-08-07 Varian Associates Beam type electronic tube

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2409644A (en) * 1941-04-11 1946-10-22 Bell Telephone Labor Inc Electron discharge apparatus
US2409608A (en) * 1941-09-24 1946-10-22 Bell Telephone Labor Inc Ultra high frequency detector
US2442662A (en) * 1942-04-15 1948-06-01 Bell Telephone Labor Inc High-frequency translating apparatus
GB584452A (en) * 1943-07-09 1947-01-15 Western Electric Co Improvements in pulsing arrangements for electron discharge devices
US2556978A (en) * 1948-10-07 1951-06-12 Bell Telephone Labor Inc Linear accelerator for charged particles
US2758245A (en) * 1950-12-14 1956-08-07 Varian Associates Beam type electronic tube

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3295066A (en) * 1962-07-05 1966-12-27 Continental Electronics Mfg Multiple modulating anode beam type electron tube and modulating circuit
US3334262A (en) * 1963-12-23 1967-08-01 Varian Associates High frequency velocity modulation electron discharge devices having replaceable beam forming and projecting assemblies
US3801854A (en) * 1972-08-24 1974-04-02 Varian Associates Modulator circuit for high power linear beam tube
US4611149A (en) * 1984-11-07 1986-09-09 Varian Associates, Inc. Beam tube with density plus velocity modulation

Also Published As

Publication number Publication date
CH336908A (fr) 1959-03-15
GB794334A (en) 1958-04-30
FR1132407A (fr) 1957-03-11

Similar Documents

Publication Publication Date Title
GB578655A (en) Improvements in or relating to high frequency electron discharge systems
US4611149A (en) Beam tube with density plus velocity modulation
US3207943A (en) High frequency tube method and apparatus
US3936695A (en) Electron collector having means for trapping secondary electrons in a linear beam microwave tube
US6133786A (en) Low impedance grid-anode interaction region for an inductive output amplifier
US2852715A (en) High frequency structure
US3346766A (en) Microwave cold cathode magnetron with internal magnet
US2284733A (en) Electron discharge device
US3038067A (en) Electrical tuning systems with traveling wave tube
US2967260A (en) Electron tube
US2860280A (en) Electric discharge device and methods
US2462137A (en) Electron discharge device
EP0753878A1 (fr) Dispositifs de tubes à faisceau d'électrons linéaire
US2748277A (en) Magnetron noise generators
US2462869A (en) Electron discharge device
US2808568A (en) Magnetron
US4140942A (en) Radio-frequency electron accelerator
US2293387A (en) Electron discharge device
US2857480A (en) Space charge grid electron beam amplifier with dual outputs
US3051865A (en) Pulsed beam tube
US2220556A (en) Ultra short wave device
US2222898A (en) High-frequency apparatus
GB856973A (en) Improvements relating to high frequency electron discharge tubes
US2914700A (en) Traveling wave tubes
US2809328A (en) Magnetron amplifiers