EP0724281A2 - Klystron - Google Patents

Klystron Download PDF

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Publication number
EP0724281A2
EP0724281A2 EP96300549A EP96300549A EP0724281A2 EP 0724281 A2 EP0724281 A2 EP 0724281A2 EP 96300549 A EP96300549 A EP 96300549A EP 96300549 A EP96300549 A EP 96300549A EP 0724281 A2 EP0724281 A2 EP 0724281A2
Authority
EP
European Patent Office
Prior art keywords
cathode
electron beams
density
ring
klystron
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.)
Withdrawn
Application number
EP96300549A
Other languages
English (en)
French (fr)
Other versions
EP0724281A3 (de
Inventor
Gweon-Jib Kim
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.)
Samsung Electronics Co Ltd
Original Assignee
Samsung Electronics Co Ltd
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 Samsung Electronics Co Ltd filed Critical Samsung Electronics Co Ltd
Publication of EP0724281A2 publication Critical patent/EP0724281A2/de
Publication of EP0724281A3 publication Critical patent/EP0724281A3/de
Withdrawn legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J23/00—Details of transit-time tubes of the types covered by group H01J25/00
    • H01J23/02—Electrodes; Magnetic control means; Screens
    • H01J23/08—Focusing arrangements, e.g. for concentrating stream of electrons, for preventing spreading of stream
    • H01J23/087—Magnetic focusing arrangements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J23/00—Details of transit-time tubes of the types covered by group H01J25/00
    • H01J23/02—Electrodes; Magnetic control means; Screens
    • H01J23/08—Focusing arrangements, e.g. for concentrating stream of electrons, for preventing spreading of stream
    • 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

Definitions

  • the present invention relates to a klystron comprising cathode means and anode means for generating an electron beam, and magnetic field generating means arranged to produce a magnetic field so as to prevent dispersion of an electron beam between the cathode and anode means.
  • JP-A-02-16533 An example of a klystron is disclosed in JP-A-02-16533.
  • This klystron is shown in Figure 9 and comprises an electron gun 202 for producing an electron beam, a high frequency circuit unit 204 for density modulating the electron beam and a collector unit 206 providing a target from the electron beam and converting the kinetic energy of the electrons in the beam into heat.
  • the klystron also comprises an input circuit 208, an input magnetic piece 210, ring-shaped permanent magnets 212, a drift channel 216 for the electron beam, an output circuit 218 and an output magnetic piece 220.
  • the output circuit 218 couples high frequency electromagnetic waves out of the klystron for supply to, for example, the cooking chamber of a microwave oven.
  • the known klystron suffers from the disadvantages that large permanent or electro-magnets are required and it is difficult to maintain a uniform magnetic flux in the drift channel. Furthermore, the efficiency of the device is low.
  • a klystron wherein the magnetic field generating means comprises a plurality magnets arranged in a ring.
  • the cathode and anode means are arranged for producing a plurality of electron beams, and the first and second magnetic field generating means are arranged to produce a magnetic field so as to prevent dispersion of each electron beam between the cathode and anode means.
  • the magnets are arranged so that their poles are at their radially inner and outer faces.
  • each magnet of one ring is magnetically coupled to a complementary magnet of the other ring by a respective yoke.
  • each of the magnets of the each ring are preferably magnetically coupled by a pole piece common to the respective ring.
  • a cathode 2 for emitting a plurality of electron beams includes a heater rod 4, an emitter rod 6, a heater 8 coupled to alternating current (120V or 240V) supply through the emitter rod 6, and an emitter 10 which thermonically emits electrons when heated by the heater.
  • a surface of the emitter 10 is formed with a plurality of emitting units 10a for emitting respective electron beams 18, as illustrated in Figure 3.
  • a thin molybdenum plate 10b is attached to the emitter 10 and is provided with holes which are aligned with the emitting units 10a.
  • the emitting units 10a are arranged in a plurality of concentric rings (preferably, a total of 25 units in three rings as illustrated in Figure 7).
  • the emitting units 10a are concave, in order to gather together the electrons emitted from the emitting units 10a.
  • the heater 8 and the emitter 10 are connected in series with each other and with an electric power source (not shown) via the heater rod 4 and the emitter rod 6.
  • the heater rod 4 and the emitter rod 6 are supported by a housing 13.
  • the magnetic field generating means 12 for generating a magnetic field to prevent dispersion of the electron beams includes a first group of permanent magnets 14, arranged in a ring around the cathode 2, a second group of permanent magnets 16, arranged in a ring around a collector (described below), first and second pole pieces 20 and 22 for guiding the magnetic flux from the first permanent magnet group 14 to the second permanent magnet group 16 so that the magnetic flux is evenly distributed in the drift channel and yokes 24, 26, 28, 30, 32 and 34 for guiding the magnetic flux from the second permanent magnet group 16 to the first permanent magnet group 14.
  • the first and second permanent magnet groups 14 and 16 are provided at opposite ends of the drift channel so that the magnetic flux is uniformly applied in the drift channel (described below).
  • the first permanent group 14 consists of six permanent magnets 36, 38, 40, 42, 44 and 46 arranged in a ring at predetermined intervals.
  • the second permanent magnet group 16 consists of six permanent magnets 48, 50, 52, 54, 56 and 58 arranged in a ring at predetermined intervals.
  • the permanent magnets 36, 38, 40, 42, 44 and 46 of the first permanent magnet group 14 have their N-poles directed radially inwardly and their S-poles directed radially outwardly, whereas the permanent magnets 48, 50,. 52, 54, 56 and 58 of the second permanent magnet group 16 have their S-poles directed radially inwardly and their N-poles directed radially outwardly.
  • the internal diameters of the magnet groups 14 and 16 are larger than the diameter of a drift channel (described below) in order that a uniform magnetic flux density exists in the drift channel.
  • the total mass (M) of the twelve permanent magnets can be determined by the following formulae 1 and 2.
  • r b is the radius of an electron beam
  • Pt is the total permeance of the electron beams 18
  • V is the potential difference between the emitter 10 and the collector (anode) (described below)
  • B is the magnetic flux density necessary in the drift channel
  • “L” is the separation between the second pole piece 22 and the emitting unit 10a.
  • the first permanent magnet group 14, the second permanent magnet group 16 and the yokes 24, 26, 28, 30, 32 and 34 are fixed to a holder 23.
  • the second pole piece 22 is connected to a drift tube (described below) so that the electron beams are maintained with a predetermined radius.
  • the yokes 24, 26,, 28, 30, 32 and 34 are formed as strips ( Figure 6) and are rectangular in cross-section.
  • the yokes 24, 26, 28, 30, 32 and 34 are arranged in a ring so that the magnetic flux follows a complete circuit.
  • Density modulation means 60 for density modulating the electron beams, emitted from the cathode 2 includes a first cavity 62 for performing a first density-modulation operation on the electron beams 18, a second cavity 64 for performing a second density-modulation operation on the beams 18, a third cavity 66 for performing a third density-modulation operation on the electron beams 18, and a fourth cavity 68 for performing a fourth density-modulation operation on the electron beams 18.
  • the density modulation amplifies the high frequency power of the beams.
  • the resonant frequencies of the second cavity 64 and the third cavity 66 are a little higher than those of the first cavity 62 and the fourth cavity 68 in order to increase the amplitude of the density modulation of the electron beams 18.
  • the first, second, third and fourth cavities 62, 64, 66 and 68 are formed with a plurality of drift channels 7 for the electron beams 18.
  • the drift channels 70 are formed by rings of parallel copper tubes 72.
  • the drift channels 70 are parallel to the central axes of the first, second, third and fourth cavities 62, 64, 66 and 68. In the illustrated case, twenty-five drift channels 70 are formed in three concentric rings ( Figure 7).
  • a feedback channel 74 is formed between the third cavity 66 and the first cavity 62 so that part of the high frequency power is fed back to the first cavity 62 from the second, third or the fourth cavities 64, 66 and 68.
  • the fourth cavity 68 is formed a little smaller than the first, second and the third cavities 62, 64 and 66 in order to increase output efficiency.
  • intervals D1, D2 and D3 at gaps 76, 78, 80 and 82 between the first cavity 62, the second cavity 64, the third cavity 66 and the fourth cavity 68 gradually decrease in order to increase the degree of mutual reaction between the first, second, third and fourth cavities 62, 63, 66 and 68.
  • intervals D1, D2 and D3 gradually decrease as shown in the following formulae (3), (4) and (5).
  • p represents the plasma frequency within the electron beams 18 determined from theory.
  • the interval D3 between the gaps 80 and 82 is smaller than the intervals D1 and D2. Furthermore, the gap 82 at the fourth cavity 68 is smaller than the other gaps 76, 78 and 80 in order to improve the characteristics of the density modulation means 60.
  • Output probe 84 includes a coupling ring 86 for extracting high frequency energy from the fourth cavity 68 and an antenna 88 for radiating, as high frequency electromagnetic waves, the energy absorbed by the coupling ring 86.
  • a collector 90 includes a collector plate 92 for collecting electrons from the second pole piece, a heat conductor 94 for removing heat generated by electrons hitting the pole piece 22.
  • the collector plate 92 is connected to the second pole piece 22 in order to easily remove the heat generated therein.
  • the heat sink 96 is attached to the heat conductor 94, which is brazed to the collector plate 92.
  • the collector plate 92 is connected to an output terminal of a 600V dc electric power source, so that an electric potential difference is established for accelerating the electron beams 18 between the emitter 10 and the collector plate 92.
  • V ⁇ P/(nPe) ⁇ 2 5 [V]
  • the electric potential difference V can be lowered, and if the number n of the electron beams 18 is increased in the above formula (11), the output P is increased.
  • an alternating current AC electric voltage of 220V is applied between the heater rod 4 and the emitter rod 6 and a DC voltage of 600V is applied to the collector plate 92.
  • THE AC voltage of 220V is applied between the heater 8 and the emitter 10 to cause the heater 8 to generate heat.
  • the heater 9 generates heat, the emitter 10 is heated to temperature above 1000°C, so that electrons are emitted from the emitting unit 10a to form the electron beams 18.
  • the electron beams 18, emitted from the emitting unit 10a of the emitter 10 toward the collector plate 92 are accelerated toward the collector plate 92 due to the electric potential difference of 600V between the emitter 10 and the collector plate 92.
  • the electron beams 18 reach the gap 76 of the first cavity 62, where an electric field is formed by a small high frequency signal introduced into space 62a at the first cavity 62 from an external signal source (not shown).
  • the electrons in the beams 18 are velocity modulated by the electric field caused by the small high frequency signal.
  • the electrons in the electron beams 18 are velocity modulated, the density of the electron beams 18 is modulated.
  • the velocity modulation of the electrons is re-generated by interaction between the second cavity 64 and the electron beams 18, by which, electron density at a portion where the density in the electron beams 18 is high is further increased.
  • the portion where the electron density was high is once again further increased i density.
  • the electron beams 18 pass by the gap 82 of the fourth cavity 68 and introduce an electromagnetic field in the space 68a of the fourth cavity 68.
  • the electrons absorbed by the second pole 22 flow to the collector plate 92 and into an electric source wire (not shown) connected to the collector plate 92.
  • the residual kinetic energy, possessed by the electrons absorbed by the second pole piece 22, generates heat in the second pole piece 22, and the heat generated in the second pole piece 22 is conducted to the heat conductor 94 and the heat sink 96 through the collector plate 92.
  • the coupling ring 86 couples to the magnetic field energy within the space 68a and extracts high frequency energy.
  • the high frequency energy is radiated into a space, for instance the cavity of a microwave oven, by the antenna 88 as microwaves.
  • the magnetic flux from the N-pole of the permanent magnets 36, 38, 40, 42, 44 and 46 is guided to the drift channel 70 and to the left side of a tube 72 through the first pole piece 20 where the magnetic flux is directed toward the tube 72 and the drift channel 70.
  • the magnetic flux radiated from the first pole piece 20 extends parallel to electron beams 18 and enters the second pole piece 22 through the drift channel 70 and the tube 72. Then, the magnetic flux is incident on the S pole of the permanent magnets 48, 50, 52, 54, 56 and 58 of the second permanent magnet group 16.
  • the magnetic flux flows via a complete closed circuit which is formed by the permanent magnets 36, 38, 40, 42, 44 and 46 of the first permanent magnet group 14 - first pole piece 20 - drift channel 70 - feedback channel 74 - second pole piece 22 - permanent magnets 48, 50, 52, 54, 56 and 58 of the second permanent magnet group 16 - yokes 26, 28, 30, 32 and 34, so that the magnetic flux necessary for the drift channel 70 where the electron beams 18 is present.
  • the X axis represents the position where the electron beams 18 proceed from the left to the right side in the drift channel 70 of the multi-beam klystron illustrated in Figure 2, and the Y axis represents the magnetic field density generated by the electron beams 18 of the multi-beam klystron.
  • the magnetic flux is uniformly distributed in the drift channel 70, so that dispersion of the electron beams 18 is inhibited, and, at the same time, the electron beams are maintained with a predetermined radius from the emitting unit 10a to the second pole piece 22.
  • a first permanent magnet group and a second permanent magnet group are arranged around a cathode and a collector, to thereby enable the density of the magnetic flux of the electron beams to be uniform across the drift channel, so that output of the device is stable and increased.
  • the efficiency is improved.

Landscapes

  • Microwave Tubes (AREA)
  • Particle Accelerators (AREA)
EP96300549A 1995-01-28 1996-01-26 Klystron Withdrawn EP0724281A3 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
KR9501735 1995-01-28
KR1019950001735A KR100197677B1 (ko) 1995-01-28 1995-01-28 멀티빔 클라이스트론

Publications (2)

Publication Number Publication Date
EP0724281A2 true EP0724281A2 (de) 1996-07-31
EP0724281A3 EP0724281A3 (de) 1998-09-02

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ID=19407531

Family Applications (1)

Application Number Title Priority Date Filing Date
EP96300549A Withdrawn EP0724281A3 (de) 1995-01-28 1996-01-26 Klystron

Country Status (4)

Country Link
EP (1) EP0724281A3 (de)
JP (1) JPH08264127A (de)
KR (1) KR100197677B1 (de)
CN (1) CN1135650A (de)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2760127A1 (fr) * 1997-02-24 1998-08-28 Litton Systems Inc Canon a electrons et klystron le comportant
GB2326274A (en) * 1997-06-13 1998-12-16 Thomson Tubes Electroniques Electron gun for multibeam electron tube
US6856081B2 (en) 2002-07-09 2005-02-15 Communications & Power Industries, Inc. Method and apparatus for magnetic focusing of off-axis electron beam
CN103346056A (zh) * 2013-06-24 2013-10-09 合肥工业大学 两级串联的太赫兹慢波结构
RU2637929C1 (ru) * 2016-07-08 2017-12-08 Акционерное общество "Плутон" Магнетрон с плавной перестройкой магнитного поля
CN112578426A (zh) * 2020-11-26 2021-03-30 中国工程物理研究院应用电子学研究所 一种可调节型阵列式法拉第筒

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100565766C (zh) * 2006-04-20 2009-12-02 中国科学院电子学研究所 空间电荷波波长压缩升频为高频率电磁波源的方法及装置
CN101604608B (zh) * 2008-06-11 2011-10-05 中国科学院电子学研究所 一种毫米波回旋速调管放大器的谐振腔结构
CN106486329B (zh) * 2015-08-25 2018-07-10 清华大学 太赫兹反射速调管及微米太赫兹反射速调管阵列
CN105261541B (zh) * 2015-11-10 2017-03-22 中国人民解放军国防科学技术大学 高功率径向线相对论速调管放大器

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB772091A (en) * 1953-11-13 1957-04-10 Siemens Ag Improvements in or relating to electron tube arrangements consisting of a travelling-wave tube and a magnetic focusing system
GB787290A (en) * 1954-09-21 1957-12-04 Siemens Ag Improvements in or relating to high-frequency electron arrangements
DE1491452A1 (de) * 1965-03-24 1969-06-12 Siemens Ag Wanderfeldroehre mit einem Permanentmagnetsystem zur Erzeugung eines im wesentlichen homogenen Magnetfeldes
GB2089562A (en) * 1980-12-15 1982-06-23 Varian Associates Permanent magnet structure for linearbeam electron tubes
GB2107111A (en) * 1981-10-07 1983-04-20 Varian Associates Adjustable-beam permanent- magnet-focused linear beam microwave tube
JPS59228342A (ja) * 1983-06-08 1984-12-21 Nec Corp 多空胴クライストロン
US4862128A (en) * 1989-04-27 1989-08-29 The United States Of America As Represented By The Secretary Of The Army Field adjustable transverse flux sources

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB772091A (en) * 1953-11-13 1957-04-10 Siemens Ag Improvements in or relating to electron tube arrangements consisting of a travelling-wave tube and a magnetic focusing system
GB787290A (en) * 1954-09-21 1957-12-04 Siemens Ag Improvements in or relating to high-frequency electron arrangements
DE1491452A1 (de) * 1965-03-24 1969-06-12 Siemens Ag Wanderfeldroehre mit einem Permanentmagnetsystem zur Erzeugung eines im wesentlichen homogenen Magnetfeldes
GB2089562A (en) * 1980-12-15 1982-06-23 Varian Associates Permanent magnet structure for linearbeam electron tubes
GB2107111A (en) * 1981-10-07 1983-04-20 Varian Associates Adjustable-beam permanent- magnet-focused linear beam microwave tube
JPS59228342A (ja) * 1983-06-08 1984-12-21 Nec Corp 多空胴クライストロン
US4862128A (en) * 1989-04-27 1989-08-29 The United States Of America As Represented By The Secretary Of The Army Field adjustable transverse flux sources

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
IWAGAMI Y ET AL: "A HIGH0POWER AND COMPACT KLYSTRON FOR DBS BAND" NEC RESEARCH AND DEVELOPMENT, vol. 37, no. 1, 1 January 1996, pages 35-40, XP000584194 *
PATENT ABSTRACTS OF JAPAN vol. 009, no. 102 (E-312), 4 May 1985 & JP 59 228342 A (NIPPON DENKI KK), 21 December 1984, *

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2760127A1 (fr) * 1997-02-24 1998-08-28 Litton Systems Inc Canon a electrons et klystron le comportant
US5932972A (en) * 1997-02-24 1999-08-03 Litton Systems, Inc. Electron gun for a multiple beam klystron
GB2326274A (en) * 1997-06-13 1998-12-16 Thomson Tubes Electroniques Electron gun for multibeam electron tube
FR2764730A1 (fr) * 1997-06-13 1998-12-18 Thomson Tubes Electroniques Canon electronique pour tube electronique multifaisceau et tube electronique multifaisceau equipe de ce canon
US6147447A (en) * 1997-06-13 2000-11-14 Thomson Tubes Electroniques Electronic gun for multibeam electron tube and multibeam electron tube with the electron gun
GB2326274B (en) * 1997-06-13 2001-11-14 Thomson Tubes Electroniques Electronic gun for mulitibeam electron tube and multibeam tube fitted out with this gun
US6856081B2 (en) 2002-07-09 2005-02-15 Communications & Power Industries, Inc. Method and apparatus for magnetic focusing of off-axis electron beam
US7005789B2 (en) 2002-07-09 2006-02-28 Communications & Power Industries, Inc. Method and apparatus for magnetic focusing of off-axis electron beam
CN103346056A (zh) * 2013-06-24 2013-10-09 合肥工业大学 两级串联的太赫兹慢波结构
CN103346056B (zh) * 2013-06-24 2015-11-04 合肥工业大学 两级串联的太赫兹慢波结构
RU2637929C1 (ru) * 2016-07-08 2017-12-08 Акционерное общество "Плутон" Магнетрон с плавной перестройкой магнитного поля
CN112578426A (zh) * 2020-11-26 2021-03-30 中国工程物理研究院应用电子学研究所 一种可调节型阵列式法拉第筒

Also Published As

Publication number Publication date
KR960030299A (ko) 1996-08-17
CN1135650A (zh) 1996-11-13
EP0724281A3 (de) 1998-09-02
KR100197677B1 (ko) 1999-06-15
JPH08264127A (ja) 1996-10-11

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