US3746916A - Magnetrons - Google Patents

Magnetrons Download PDF

Info

Publication number
US3746916A
US3746916A US00247821A US3746916DA US3746916A US 3746916 A US3746916 A US 3746916A US 00247821 A US00247821 A US 00247821A US 3746916D A US3746916D A US 3746916DA US 3746916 A US3746916 A US 3746916A
Authority
US
United States
Prior art keywords
sealing member
anode electrode
magnetron
magnet
cylinder
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
US00247821A
Other languages
English (en)
Inventor
T Oguro
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.)
Hitachi Ltd
Original Assignee
Hitachi 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 Hitachi Ltd filed Critical Hitachi Ltd
Application granted granted Critical
Publication of US3746916A publication Critical patent/US3746916A/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
    • H01J23/00—Details of transit-time tubes of the types covered by group H01J25/00
    • H01J23/02—Electrodes; Magnetic control means; Screens
    • H01J23/10—Magnet systems for directing or deflecting the discharge along a desired path, e.g. a spiral path
    • 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

Definitions

  • ABSTRACT in a magnetron of the type wherein an annular anode electrode and a cathode electrode are contained in an interaction space in an evacuated envelope and magnetic flux acting upon the interaction space is produced by a magnet positioned on the outside of the envelope, first and second sealing members are sealed to the opposite ends of the anode electrode to define the evacuated envelope, a first magnet is disposed coaxially with the anode electrode substantially in contact with the outer surface of the first sealing member and a second magnet is disposed coaxially with the anode electrode substantially in contact with the outer surface of the second sealing member.
  • This invention relates to a magnetron and more particularly to a magnetron suitable for use in an electronic range or a microwave oven, a thawing equipment or the like.
  • Another object of this invention is to provide an improved magnetron according to which it is possible to dispose the magnet as near as possible to the interaction space thereby providing a magnetron which can operate efficiently with small size.
  • Still another object of this invention is to provide a magnetron of a construction in which it is possible to reduce the width of the yoke with respect to the diameter of the anode electrode thereby'enabling to supply cooling air to the magnetron in any direction.
  • a further object of this invention is to provide a magnetron with a magnet of small size thereby broadening the space in which the cooling fin can be mounted.
  • Still further object of this invention is to provide a novel magnetron wherein the magnet is disposed outside of the interaction space of the magnetron which is required to be maintained at an air tight vacuum condition thereby eliminating the problem caused by the gas released from the magnet.
  • Yet another object of this invention is to provide a novel magnetron wherein the magnet is disposed remote from the anode cylinder thereby reducing heat conduction from the anode to the magnet and wherein the magnet is disposed outside the envelope thereby decreasing the effect of the radiant heat from the cathode electrode to the magnet.
  • Another object of this invention is to provide a novel magnetron wherein the magnet is disposed outside of the envelope thereby magnetically shielding the component parts contained therein against a ferromagnetic body, such as an iron sheet situated about the magnetron.
  • a magnetron comprising an annular anode electrode including a plurality of inwardly projecting vanes, a cathode electrode disposed concentrically with the anode electrode, a first nonmagnetic sealing member sealed to one end of the anode electrode, a second nonmagnetic sealing member sealed to the other end of the anode electrode, the anode electrode and thefirst and second sealing members cooperating to define an evacuated envelope, a first magnet disposed coaxially with the anode electrode ans substantially in contact with the outer surface of the first sealing member, and a second magnet disposed coaxially with the anode electrode and substantially in contact with the outer surface of the second sealing member.
  • the magnetron is provided with a metal tube extending through the side wall of the annular anode electrode or the bottom of the second sealing member and an output conductor extends through the metal tube.
  • FIG. 1 shows a longitudinal section of a magnetron embodying the invention
  • FIG. 2 shows a sectional view of the magnetron shown in FIG. 1 taken along a line I] ll;
  • FIG. 3 shows an top plan view of the magnetron shown in FIG. 1;
  • FIG. 4 is a perspective view of a toroidal magnet utilized in the magnetron shown in FIG. 1;
  • FIGS. 5 and 6 show perspective views of two types of the yoke utilized in the magnetron shown in FIG. 1 and FIGS. 7 and 8 show a longitudinal view of a modified magnetron embodying the invention.
  • the magnetron shown therein comrpises an annular anode electrode 10 including a plurality of radial vanes 11, a first sealing member 12 hermetically connected to the upper edge of the anode l0 and including a central cylinder 14 extending upwardly, and a second sealing member 13 hermetically connected to the lower edge of the anode, the sealing member 13 being provided with an exhaust tube 33 and ametal tube 25 for passing an antenna conductor 27 to the outside on the bottom thereof at positions remote from the central axis.
  • the first and second shielding members 12 and 13 are made of thin metal sheets of low permeability or having a characteristic of being saturated at a low fluxdensity such as copper alloys Monel metal or constantan, for example, or copper or the like.
  • a first magnet of toroidal form 15 is disposed to surround the cylinder 14 of the first sealing member 12 for embracing the cylinder 14.
  • a cathode electrode 18 concentrically with anode 10, the cathode electrode being supported by a cathode support 19.
  • cathode support 19 protrudes upwardly to form a cathode terminal 20 beyond the upper end of a cylindrical insulator bushing 17 connected to the upper end of cylinder 14 of the first sealing member 12.
  • the cathode support 19 is supported by a rod 21 extending through an insulator disc 22 overlying the flattened upper end of the support 19.
  • anode electrode 10, cylinder 14 and cathode electrode 20 are arranged in concentric relation.
  • a cylindrical second magnet 16 is disposed on the under surface of the second sealing member 13 in concentric relation with the interaction space 100.
  • Yokes 23 and 24 of iron plates are provided to fix in position the component parts of the magnetron described above and to form a closed magnetic circuit for the first and second magnets 15 and 16.
  • a metal fixture 28 is connected to the lower end of the metal tube 25 depending from the second sealing member 15 through a cylindrical insulator bushing 26, the metal fixture being electrically connected to the lower end of copper rod 27 adapted to transmit the electromagnetic energy generated in the interaction space 100 thereby acting as an antenna.
  • a flange 29 is connected to the metal tube 25 to receive a gasket 30 for facilitating the electrical connection to an external load (not shown).
  • the toroidal magnet 15 comprises two halves 15a and 15b.
  • the yoke 24 takes the form of a flat rectangular plate with a notch 24a at the center of one longitudinal edge and extending towards the center of the plate for receiving the metal tube 25 depending from the second sealing member 13.
  • the yoke 24 is formed with a plurality of openings 24b through 24e used to secure the yoke.
  • yoke 23 comprises two identical halves 23a and 23b, each having vertical portions, upper horizontal portions and bottom horizontal portions which are secured to the upper surface of horizontal yoke 24.
  • the upper horizontal portions are provided with semicircular notches 23c and 23d adapted to receive metal tube 14 of the first sealing member 12 and the bottom horizontal portions are provided with threaded openings 23e and 23f for receiving screws used to secure the yoke 23 to the horizontal yoke 24.
  • the width of the yoke 23 is designed to be smaller than the diameter of anode electrode 10.
  • FIG. 7 illustrates a modified magnetron wherein the output of magnetron is taken out from one side of the anode electrode.
  • yokes are not shown in FIG. 7 and component parts identical to those shown are designated by the same reference numerals.
  • anode cylinder 34 comprising anode electrode has a longer length than that shown in FIG. 1 and metal tube 25 is secured to anode cylinder 34 in the radial direction thereof. Since the axial length of the anode cylinder 34 is increased, the bottom of the second sealing member 13 is raised or depressed inwardly so as not to decrease the effective magnetic flux acting in the interaction space 100.
  • the cathode support 19 and the cylinder 14 of the first sealing member 12 are shown to coaxially extend in the vertical direction, it is also possible as shown in FIG. 8 to construct the first sealing member 12 in the form of a cup like the second sealing member 13 and to cause the cathode supports 19a, 19b to extend through the anode cylinder 34 or the sealing member. Then it is possible to use a first magnet 16a in the form ofa cylinder like the second magnet 16 thereby miniaturizing the magnetron.
  • the distribution of the magnetic flux acting upon the interaction space can be adjusted by varying the height or the cross-sectional area of the magnets and that the flux distribution can be improved by mounting ferromagnetic metal plates on the inner surface of the first and second sealing members near the interaction space.
  • a magnetron assembly comprising an evacuated discharge device having an annular anode electrode including a plurality of inwardly projecting vanes, a cathode electrode disposed concentrically with said anode electrode, a first nonmagnetic thin-wall sealing member sealed to one end of said anode electrode, a second nonmagnetic thin-wall sealing member sealed to the other end of said anode electrode, said anode electrode and said first and second sealing members cooperating to define an evacuated envelope with said thin-wall sealing members opposed and closely spaced to the axial ends of the interaction space between said anode and cathode electrodes; a first magnet disposed coaxially with said anode electrode with a first surface substantially in contact with the outer surface of said first sealing member; a second magnet disposed coaxially with said anode electrode with a first surface substantially in contact with the outer surface of said second sealing member; and a ferromagnetic yoke extending from the opposite surfaces of said first and second magnets to support said assembly and provide
  • both said first magnet and said second magnet are in the form of a cylinder.

Landscapes

  • Microwave Tubes (AREA)
US00247821A 1971-04-26 1972-04-26 Magnetrons Expired - Lifetime US3746916A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP46026780 1971-04-26

Publications (1)

Publication Number Publication Date
US3746916A true US3746916A (en) 1973-07-17

Family

ID=12202803

Family Applications (1)

Application Number Title Priority Date Filing Date
US00247821A Expired - Lifetime US3746916A (en) 1971-04-26 1972-04-26 Magnetrons

Country Status (5)

Country Link
US (1) US3746916A (ja)
DE (1) DE2220463C3 (ja)
FR (1) FR2134500B1 (ja)
GB (1) GB1344415A (ja)
SE (1) SE372371B (ja)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3916247A (en) * 1973-07-16 1975-10-28 Tokyo Shibaura Electric Co Shell type magnetron device
US4039892A (en) * 1975-03-13 1977-08-02 U.S. Philips Corporation Resonant cavity magnetron having a magnet system and magnetron destined for such a combination
US4044279A (en) * 1975-07-23 1977-08-23 Hitachi, Ltd. Magnetrons
US4075534A (en) * 1975-09-01 1978-02-21 Tokyo Shibaura Electric Co., Ltd. Magnetron with holding means to support a pair of permanent magnets

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3849737A (en) * 1972-12-18 1974-11-19 Hitachi Ltd Magnetron with choke structure for reducing harmonics in output
JPS5841717Y2 (ja) * 1978-10-16 1983-09-20 株式会社東芝 マグネトロン

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2428888A (en) * 1946-04-15 1947-10-14 Gen Electric High-frequency electric discharge device
US3229152A (en) * 1961-10-19 1966-01-11 Gen Electric Magnetron having evacuated discharge subassembly united with unevacuated magnetic andresonant cavity structure
US3315121A (en) * 1961-04-27 1967-04-18 Gen Electric Crossed-field electric discharge device
US3465201A (en) * 1967-03-27 1969-09-02 Philips Corp Magnetron casing
US3562579A (en) * 1968-06-11 1971-02-09 Nippon Electric Co Electron discharge device employing inexpensive permanent magnets if significantly reduced size
US3588589A (en) * 1968-08-17 1971-06-28 Philips Corp Magnetron and connection system for magnetron

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1063283B (de) * 1958-06-14 1959-08-13 Mikrowellen Ges M B H Deutsche Anordnung von Kuehlblechen fuer Elektronenroehren mit metallischem Gefaessmantel, insbesondere Magnetfeldroehren
FR1285778A (fr) * 1961-04-06 1962-02-23 Litton Industries Inc Magnétron

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2428888A (en) * 1946-04-15 1947-10-14 Gen Electric High-frequency electric discharge device
US3315121A (en) * 1961-04-27 1967-04-18 Gen Electric Crossed-field electric discharge device
US3229152A (en) * 1961-10-19 1966-01-11 Gen Electric Magnetron having evacuated discharge subassembly united with unevacuated magnetic andresonant cavity structure
US3465201A (en) * 1967-03-27 1969-09-02 Philips Corp Magnetron casing
US3562579A (en) * 1968-06-11 1971-02-09 Nippon Electric Co Electron discharge device employing inexpensive permanent magnets if significantly reduced size
US3588589A (en) * 1968-08-17 1971-06-28 Philips Corp Magnetron and connection system for magnetron

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3916247A (en) * 1973-07-16 1975-10-28 Tokyo Shibaura Electric Co Shell type magnetron device
US4039892A (en) * 1975-03-13 1977-08-02 U.S. Philips Corporation Resonant cavity magnetron having a magnet system and magnetron destined for such a combination
US4044279A (en) * 1975-07-23 1977-08-23 Hitachi, Ltd. Magnetrons
US4075534A (en) * 1975-09-01 1978-02-21 Tokyo Shibaura Electric Co., Ltd. Magnetron with holding means to support a pair of permanent magnets

Also Published As

Publication number Publication date
FR2134500B1 (ja) 1976-06-11
FR2134500A1 (ja) 1972-12-08
DE2220463A1 (de) 1972-11-09
GB1344415A (en) 1974-01-23
DE2220463C3 (de) 1975-09-25
DE2220463B2 (de) 1975-02-20
SE372371B (ja) 1974-12-16

Similar Documents

Publication Publication Date Title
US2788465A (en) Traveling wave electron discharge device
US3746916A (en) Magnetrons
US2984762A (en) Electron beam tube and magnetic circuitry therefor
US2075855A (en) Magnetron
US2428193A (en) Magnetron
US3987333A (en) Magnetron comprising a radially magnetized permanent magnet and an axially magnetized permanent magnet
US2416899A (en) Electronic discharge device of the magnetron type
US2288380A (en) High frequency radio tube
US3562579A (en) Electron discharge device employing inexpensive permanent magnets if significantly reduced size
JPS5841717Y2 (ja) マグネトロン
US4204138A (en) Permanent magnet-containing magnetron
US4027194A (en) Core magnetron magnetic circuit having a temperature coefficient approximately zero and permeance related
US3716750A (en) Magnetrons
US3344306A (en) Klystron having temperature modifying means for the electrodes therein and the focusing magnetic circuit
US3223881A (en) Magnetron mounting structure and output coupling
US2790105A (en) Traveling wave tubes
US3158780A (en) Voltage-tuneable magnetron
JPS5818732B2 (ja) マグネトロン
GB1457045A (en) Magnetron device
US2476130A (en) Electron discharge device of the magnetron type
US2860285A (en) Electron discharge devices
GB632210A (en) Improvements in or relating to magnetrons
US4482870A (en) Magnetron with magnetic yoke having annular projection
US4163922A (en) Magnetrons
US2814755A (en) Traveling wave electron discharge device