EP0352961B1 - Klystrode multiplicateur de fréquence - Google Patents

Klystrode multiplicateur de fréquence Download PDF

Info

Publication number
EP0352961B1
EP0352961B1 EP19890307345 EP89307345A EP0352961B1 EP 0352961 B1 EP0352961 B1 EP 0352961B1 EP 19890307345 EP19890307345 EP 19890307345 EP 89307345 A EP89307345 A EP 89307345A EP 0352961 B1 EP0352961 B1 EP 0352961B1
Authority
EP
European Patent Office
Prior art keywords
tube
gap
frequency
cavity
grid
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
EP19890307345
Other languages
German (de)
English (en)
Other versions
EP0352961A1 (fr
Inventor
Louis T. Zitelli
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
Varian Associates 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 Varian Associates Inc filed Critical Varian Associates Inc
Publication of EP0352961A1 publication Critical patent/EP0352961A1/fr
Application granted granted Critical
Publication of EP0352961B1 publication Critical patent/EP0352961B1/fr
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
    • H01J25/04—Tubes having one or more resonators, without reflection of the electron stream, and in which the modulation produced in the modulator zone is mainly density modulation, e.g. Heaff tube

Definitions

  • the invention pertains to linear-beam electron tubes in which the beam is density-modulated by a control grid.
  • Such tubes have been found useful for generating amplitude-modulated ultra-high-frequency radio waves such as television broadcast transmission, with efficiency superior to klystrons.
  • Radio transmitters have generally used grid-controlled electron tubes such as tetrodes.
  • UHF ultra-high frequency range
  • the gridded tubes reached their performance limits of power or frequency due to the transit times of electrons across the gaps between electrodes becoming comparable to the period of the generated wave.
  • the first development to overcome these limits was the UHF klystron in which transit time is taken advantage of rather than being unwanted.
  • the klystron is very inefficient for amplifying an amplitude-modulated wave such as the standard TV signal where amplitude corresponds to brightness.
  • the klystron has to have enough power in the beam to generate the signal peaks, such as black and the still stronger synchronization pulses.
  • the average power needed for an average signal is several times smaller, but the unused beam power is wasted as heat in the spent-beam collector.
  • Preist and Shrader made a high-power tube using klystron beam technology and a much larger carbon grid to which the rf signal was applied in class B or class C modulation.
  • the video-frequency power envelope of the beam is thus just what is needed to generate the instantaneous signal amplitude.
  • the power efficiency in TV transmission was increased greatly.
  • US-A-4611149 can be taken to describe a linear-beam frequency-multiplier electron vacuum tube comprising an electron emissive cathode; an electron-permeable control grid closely spaced from the emissive surface of said cathode; means for supplying a high-frequency signal voltage between said cathode and said grid; an anode spaced from said grid and facing said emissive surface, apertured for passage of an electron beam from said cathode; a hollow conductive drift tube for transmitting said beam beyond said anode, the drift tube being formed with a first and a second gap, the second gap being on one side of the first gap near the anode; a first hollow cavity located around the first gap in said drift tube to form a re-entrant cavity resonant at a frequency near the frequency of said signal voltage; a second hollow cavity located around the second gap in said drift tube to form a re-entrant cavity resonant at a frequency higher than said signal voltage frequency; means for extracting wave energy at
  • the present invention is set out in Claim 1.
  • Figure 1 illustrates a tube which has a thermionic cathode with preferably concave emitting surface 11, heated by a radiant wire coil 12.
  • a convergent beam of electrons 14 is drawn from emitter 11 by a hollow anode 16.
  • Directly in front of emitter 11 is an electron-permeable grid, preferably of pyrolytic graphite bars 18 bounding apertures 20.
  • Beam 14 is converged toward anode 16 by the convergent electrostatic field. It passes through anode 16 and an annular ferro-magnetic polepiece 22 which forms one terminus of a strong axial magnetic focusing field generated by a surrounding solenoid coil (not shown). Beam 14 then passes through a hollow metallic drift tube 24 and crosses an interaction gap 26 between input drift tube 24 and an exit drift tube 28. Drift tubes 24 and 28 form the center conductor of a coaxial cavity 30, resonant at preferably a frequency just above the frequency band of the tube's input signal.
  • Cavity 32 is resonant at a harmonic of the band-center input frequency and is excited by the harmonic component of the modulated beam current.
  • beam 14 After leaving harmonic output cavity 32, beam 14 passes through a second annular polepiece 37 which terminates most of the axial field. Beam 14 then expands under its own space-charge repulsion and is collected on the hollow, inner surface of a beam collector 38. The heat energy dissipated is removed by a coolant 40 (such as water) circulating from a coolant pipe 42.
  • a coolant 40 such as water
  • an input signal to be amplified and frequency-multiplied is fed in from a coaxial transmission line 46 through a coaxial dielectric vacuum window 48 to the space between the grid support 50 (usually at rf ground) and cathode support 52. This space may be partially blocked from input line 46 to form a resonant cavity to properly match impedances.
  • Drift tube 34 of harmonic cavity 32 is smaller in diameter than drift tube 24 of fundamental cavity 30, to provide good interactive coupling between beam and cavity at the higher frequency.
  • the beam size is tapered down by a gradual increase in strength of the focussing magnetic field by increasing the wire turns per unit length of the solenoid. Shaping of polepieces 22, 37 to concave-convex shapes may also be used to generate the tapered field. In the strong "confined flow" focussing, the electrons follow the magnetic flux lines.
  • Useful harmonic energy is extracted from output cavity 32 via a coupling orifice 54 into an output waveguide 56 which is sealed off by a dielectric vacuum window 57.
  • FIG. 4 shows calculated trajectories (in rf phase) of sample electrons where harmonic content of beam current is enhanced by bunching at a harmonic frequency.
  • FIG. 2 is a graph of calculated harmonic components of beam current in the present frequency multiplier, plotted as functions of distance Z from the amplitude-modulating grid.
  • Graph 60 is the fundamental component having a decreasing value 62 after leaving grid 18 due to space-charge debunching.
  • beam 14 receives velocity modulation which in following drift tube 28 increases the A.C. component 64.
  • the A.C. component reaches a maximum value 66.
  • an output circuit with a gap at the position of harmonic gap 36 but resonant at the fundamental frequency gives a conversion efficiency of 87%.
  • the second graph shows the second harmonic component 70 of beam current.
  • the space-charge debunching 72 is more severe than for the fundamental current 60 due to the shorter wavelength.
  • the second harmonic current also increases faster due to the increased number of wavelengths traversed.
  • the peak value 76 is reached at about the same distance as that of fundamental 60. At this point output gap 36 is located.
  • the conversion efficiency for second harmonic power was calculated as 75%, a value completely out of reach in klystrons or simple grid-controlled tubes.
  • the second or third harmonic would be used.
  • the limits of power and frequency available from the multiplier are greatly extended.

Landscapes

  • Microwave Tubes (AREA)
  • Microwave Amplifiers (AREA)

Claims (10)

  1. Tube électronique à vide multiplicateur de fréquence à faisceau linéaire comportant :
       une cathode émissive d'électrons (10) pour l'émission d'un faisceau d'électrons ;
       une grille de commande (11) perméable aux électrons pour commander ledit faisceau, ladite grille étant très voisine de la surface émissive de ladite cathode ;
       un moyen (46-52) pour fournir une tension de signal à haute fréquence entre ladite cathode et ladite grille ;
       une anode (16) espacée de ladite grille et faisant face à ladite surface émissive, comportant des ouvertures pour le passage dudit faisceau d'électrons ;
       un tube de transit conducteur creux (24, 28) pour transmettre ledit faisceau au-delà de ladite anode, le tube de transit comportant un premier et un deuxième espaces, le deuxième espace étant situé du côté du premier espace éloigné de l'anode ;
       une première cavité creuse (30) destinée à la modulation en vitesse dudit faisceau, ladite première cavité creuse étant située autour du premier espace dans ledit tube de transit pour constituer une cavité de ré-entrée résonant à une fréquence voisine de la fréquence de ladite tension de signal ;
       une deuxième cavité creuse (32) située autour du deuxième espace dans ledit tube de transit pour constituer une cavité de ré-entrée résonant à une fréquence voisine d'un harmonique de ladite fréquence de tension du signal ;
       un moyen (54-57) pour extraire l'énergie de l'onde à ladite fréquence d'harmonique depuis ladite deuxième cavité ; et
       un moyen (38) pour recueillir ledit faisceau en aval de ladite deuxième cavité.
  2. Tube selon la revendication 1, dans lequel ladite première cavité (30) est résonante à une fréquence supérieure à la bande de fréquence dudit signal et inférieure à la bande de fréquence dudit harmonique.
  3. Tube selon la revendication 1 ou la revendication 2, dans lequel ladite deuxième cavité (32) est résonante à une fréquence située approximativement au centre de la bande de fréquence dudit harmonique.
  4. Tube selon l'une quelconque des revendications 1 à 3, dans lequel ladite grille (11) est en graphite pyrolytique.
  5. Tube selon l'une quelconque des revendications 1 à 4, dans lequel ledit moyen d'alimentation en une tension de signal comporte un circuit résonant connecté à ladite cathode et à ladite grille.
  6. Tube selon l'une quelconque des revendications 1 à 5, dans lequel ledit tube de transit (24, 28) est plus petit au niveau dudit deuxième espace (36) qu'au niveau dudit premier espace (26).
  7. Tube selon l'une quelconque des revendications 1 à 6, dans lequel ledit deuxième espace (36) est plus court que ledit premier espace (26).
  8. Tube selon l'une quelconque des revendications 1 à 7, comportant un moyen (22, 37) pour produire un champ magnétique stable dans la direction dudit faisceau entre ladite anode et ledit deuxième espace.
  9. Tube selon la revendication 8, dans lequel ledit moyen de champ magnétique comporte des pièces polaires ferromagnétiques (22, 37) entourant ledit tube de transit.
  10. Tube selon la revendication 8, dans lequel ledit moyen de champ magnétique est agencé pour produire un champ magnétique plus puissant au niveau dudit deuxième espace qu'au niveau dudit premier espace, grâce à quoi ledit faisceau est comprimé entre lesdits espaces.
EP19890307345 1988-07-25 1989-07-20 Klystrode multiplicateur de fréquence Expired - Lifetime EP0352961B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US22349088A 1988-07-25 1988-07-25
US223490 1988-07-25

Publications (2)

Publication Number Publication Date
EP0352961A1 EP0352961A1 (fr) 1990-01-31
EP0352961B1 true EP0352961B1 (fr) 1994-09-07

Family

ID=22836735

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19890307345 Expired - Lifetime EP0352961B1 (fr) 1988-07-25 1989-07-20 Klystrode multiplicateur de fréquence

Country Status (3)

Country Link
EP (1) EP0352961B1 (fr)
JP (1) JPH0279330A (fr)
DE (1) DE68918021T2 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10145215B2 (en) 2014-12-31 2018-12-04 Halliburton Energy Services, Inc. Drill bit with electrical power generator

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1273140B (it) * 1993-04-13 1997-07-04 Eev Ltd Tubo a fascio elettronico lineare
GB9724960D0 (en) 1997-11-27 1998-01-28 Eev Ltd Electron beam tubes

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1143751B (it) * 1977-08-01 1986-10-22 Sits Soc It Telecom Siemens Klystron oscillatore accordabile
US4527091A (en) * 1983-06-09 1985-07-02 Varian Associates, Inc. Density modulated electron beam tube with enhanced gain

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10145215B2 (en) 2014-12-31 2018-12-04 Halliburton Energy Services, Inc. Drill bit with electrical power generator

Also Published As

Publication number Publication date
DE68918021D1 (de) 1994-10-13
JPH0279330A (ja) 1990-03-19
EP0352961A1 (fr) 1990-01-31
DE68918021T2 (de) 1995-01-12

Similar Documents

Publication Publication Date Title
US4527091A (en) Density modulated electron beam tube with enhanced gain
US5650751A (en) Inductive output tube with multistage depressed collector electrodes providing a near-constant efficiency
EP0181214B1 (fr) Tube à faisceau d'électrons focalisé avec modulation de densité ainsi que de vitesse
US6380803B2 (en) Linear amplifier having discrete resonant circuit elements and providing near-constant efficiency across a wide range of output power
US6326730B1 (en) Low-power wide-bandwidth klystron
US5986388A (en) Field-emission cold-cathode electron gun having emitter tips between the top surface of gate electrode and focusing electrode
US5355093A (en) Compact microwave and millimeter wave amplifier
EP0352961B1 (fr) Klystrode multiplicateur de fréquence
US3123735A (en) Broadband crossed-field amplifier with slow wave structure
US20040174211A1 (en) Inductive output tube having a broadband circuit
US3289032A (en) Microwave hybrid tube apparatus
US6191651B1 (en) Inductive output amplifier output cavity structure
US7474148B2 (en) Amplifier comprising an electronic tube provided with collectors biased by at least two DC bias sources
GB2369488A (en) Linear Amplifier
Symons Klystrons for UHF television
EP1675150A2 (fr) Arrangement de sortie pour un tube à faisceau d'électrons
US3924152A (en) Electron beam amplifier tube with mismatched circuit sever
US3296483A (en) Wideband amplifier utilizing common electron beam for interaction with high-frequency traveling-wave line and with low-frequency electron multiplier
Whitaker Microwave Vacuum Devices
JPH0568817B2 (fr)
McDowell et al. 2.4 Crossed-Field Noise Generation Devices
Whitaker et al. Microwave power tubes
JPH0568818B2 (fr)
JPH0568816B2 (fr)
Foster The development of a 110 kilowatt high efficiency UHF TV klystron

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB IT NL

17P Request for examination filed

Effective date: 19900608

17Q First examination report despatched

Effective date: 19920702

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB IT NL

REF Corresponds to:

Ref document number: 68918021

Country of ref document: DE

Date of ref document: 19941013

ITF It: translation for a ep patent filed
ET Fr: translation filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19950616

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19950623

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19950627

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19950628

Year of fee payment: 7

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19960720

REG Reference to a national code

Ref country code: GB

Ref legal event code: 732E

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Effective date: 19970201

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19960720

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19970328

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 19970201

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19970402

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20050720