US3731137A - Coaxial magnetron - Google Patents

Coaxial magnetron Download PDF

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Publication number
US3731137A
US3731137A US00223250A US3731137DA US3731137A US 3731137 A US3731137 A US 3731137A US 00223250 A US00223250 A US 00223250A US 3731137D A US3731137D A US 3731137DA US 3731137 A US3731137 A US 3731137A
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United States
Prior art keywords
tuning
wall
coaxial
members
ring members
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Expired - Lifetime
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US00223250A
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English (en)
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R Foreman
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Raytheon Co
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Raytheon Co
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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
    • H01J23/16—Circuit elements, having distributed capacitance and inductance, structurally associated with the tube and interacting with the discharge
    • H01J23/18—Resonators
    • H01J23/20—Cavity resonators; Adjustment or tuning thereof
    • H01J23/207—Tuning of single resonator

Definitions

  • ABSTRACT A coaxial magnetron having a cylindrical cavity operating in a circular mode is tuned by means circumferentially disposed in the region of maximum electric field intensity.
  • a ring tuner is retained within an annular groove at the midpoint of the outer cavity wall and adapted to be reciprocated in introduce a dissymmetry in the cavity geometry along a path transverse to its axis. The paths of the electric field currents are altered by each excursion of the tuner.
  • Dither tuning of the disclosed structure provides a frequency agility in transmission systems over a portion of the frequency band.
  • Another embodiment provides for the combination with a large plate-type tuner to add a fine tuning capability over a portion of a broad frequency band. Temperature compensation is also attainable by means of the ring tuner arrangement.
  • the invention relates to crossed field electron discharge devices of the coaxial magnetron type and, in particular, to a tuning structure for such devices.
  • US. Pat. No. 2,854,603 issued Sept. 30, 1958, to RJ. Collier and J. Feinstein discloses a coaxial magnetron device having an inner and an outer resonant system.
  • the inner system comprises a plurality of radially extending vane members extending from an anode wall defining therebetween resonant cavities circumferentially disposed around a central cathode.
  • An outer system is defined by an annular wall member and the cylindrical anode wall to provide an outer circular coaxial cavity resonator.
  • Coaxial magnetrons generally provide for the outer cavity resonator to operate in the TE circular electric and magnetic mode.
  • Electromagnetic energy is coupled from alternate inner cavity resonators by slots extending within the common anode boundary wall.
  • the inner system generally operates in the pi-mode and the coupling slots together with slot mode absorbing structures are dimensioned to provide for efficient coupling of the respective modes.
  • the electric currents are circumferential around the cavity walls while the magnetic fields are transversely disposed in a direction parallel to the axis of the device.
  • the large massive tuning structures vary the distance between the upper and lower end walls of the cavity resonator to reorient the field distributions of both the electric and magnetic fields and thereby provide for the alteration of the resonant frequency.
  • a lightweight tuning structure which avoids the difficulties of the large massive structures and provides for fine, as well as, dither tuning capability is, therefore, desirable for electromagnetic energy propagation devices and systems.
  • the present invention provides a coaxial magnetron having an outer cavity resonator with tuning means for varying its dimension in and near the region of maximum electric field intensity when operated in the TE mode.
  • mechanical means provide for reciprocating motion of split ring tuner structures having at least one end anchored.
  • the deformation of the ring tuner provides a dissymmetry in the cavity geometry with the maximum excursion deforming the substantially circular cavity to have a slightly elliptical configuration.
  • the introduction of conductive tuner material in the cavity alters the path of the electric currents.
  • a groove housing the tuning structure is provided by an annular wall structure girdling the outer cavity resonator walls. The depth of the groove provides the limits of the tuning structure excursion.
  • FIG. 1 is a diagrammatic cross-sectional view of the principal components embodied in the present invention.
  • FIG. 2 is a front elevational view of a coaxial magnetron embodying the present invention
  • FIG. 3 is a side elevational view of the embodiment shown in FIG. 2;
  • FIG. 4 is a curve illustrating the tuning characteristics of an illustrative embodiment of the invention.
  • FIG. 5 is a cross-sectional view taken along the lin 5-5 in FIG. 3;
  • FIG. 6 is a cross-sectional view taken along the line 6--6 in FIG. 5;
  • FIG. 7 is a cross-sectional view taken along the line 7 -7 in FIG. 3;
  • FIG. 8 is a vertical cross-sectional view taken along the line 8-8 in FIG. 2;
  • FIG. 9 is anelevation viewed in the direction indicated by the line 99 in FIG. '7;
  • FIG. 10 is an elevation view of an alternative mechanical actuating structure for the embodiment of the invention.
  • FIG. 11 is adiagrammatic representation in section of an alternative embodiment of the invention.
  • the illustrative coaxial magnetron comprises an inner and an outer resonant system housed within envelope 12.
  • a mechanically actuated tuner assembly 14 including motor driven means for action of the tuning structures includes a gear housing 16 and resolver means 18 for readout of the frequency.
  • a cathode support assembly 20 extends coaxially from the envelope 12. Cooling fins 22 surround the envelope 12 and an output waveguide window assembly 24 for coupling of the electromagnetic energy to the utilization load is also provided.
  • the magnetic field producing-means 28 includes substantially C-shaped permanent magnets 30 and 32 which contact inner pole piece members (not visible in these views).
  • the magnetic field extends parallel to the axis of the device and the electric field is oriented transver- 'sely thereto to provide for crossed field interaction in the region between the cathode and the anode members.
  • the embodiment of the invention includes mechanical actuating means 34 with intermediate mechanical coupling means for translation of motion from the tuner assembly 14 and gear housing 16 into reciprocal motion of the tuner structure.
  • the inner resonant system 38 includes a cathode member 40 centrally disposed within an array of circumferentially disposed anode vane elements 42 extending radially from common boundary wall 44.
  • a plurality of cavity resonators 46 are defined between the anode elements.
  • Alternate slots 48 provide for coupling of the pi-mode generated energy in the inner system to the outer coaxial cavity resonator 50 defined by the common boundary wall 44 and an external cylindrical wall member 52.
  • the outer cavity resonator system is dimensioned to operate in the TE mode.
  • a plate member 54 is axially translated within the cavity resonator 50 to tune the magnetron over a broad frequency band. Suitable mechanical actuating mans,
  • a split ring tuner structure 60 is provided within a groove 62 disposed at a point near the middle of the wall member 52 where the electric field intensity is at the maximum value.
  • the deformation of the ring tuner 60 provides for introduction of a conductive material within the cavity and provides a varying path for the electric currents which, as noted for the TE mode, are circumferential along the wall 52 of the coaxial cavity resonator 50.
  • the depth of the groove 62 determines the excursion of the tuner structure. Rapid deformation of the external cavity wall contour in the been shown to have similar linear tuning ranges over up to 200 MHz at other bands. With motor driven dither actuator means, to be hereinafter described, coupled to the disclosed tuning structure and operated at speeds of up to 12,000 r.p.m.s an excursion of the tuning range of 200 cycles per minute will result.
  • Envelope 12 is defined by annular end wall members 66 and 68 hermetically sealed to outer cylindrical wall member 52.
  • the anode vane elements 42 are appended to the common anode boundary wall 44 and extend radially inwardly to define therebetween cavity resonators 46 of the inner resonant system.
  • Cathode 40 is supported axially by the cylindrical support assembly 20 which includes a tubular member 70 and is secured to magnetic inner pole piece member 72. Electrical leads for energizing cathode heater 74, as well as the high voltage leads, are introduced through the cathode support assembly 20 to the appropriate anode and cathode members.
  • the previously described magnetic circuit producing means 28 contacts inner pole piece member 72 as well as pole piece adapters 76.
  • the outer resonant system includes coaxial cavity resonator 50 defined by the common anode boundary wall 44 and the outer cylindrical wall member 52. Slots 48 in wall 44 provide for the coupling and locking of the energy between inner and outer resonant systems. Any degenerate energy modes are suppressed by annular lossy member 78 disposed within end wall member 66 and member 80 adjacent to the quarter-wavelength channel choke 82 in end wall member 68.
  • the external coaxial cavity resonator 50 is coupled through iris 84 and a transformer section to the utilization load by means of output waveguide assembly 24.
  • An exhaust tubulation 86 in outer wall member 52, as well as, a mounting and anchor plate 88 together with anchor screw means 90 and 92 comprise the remainder of the coaxial magnetron structure.
  • An axially translated plate member 94 for broad frequency tuning is actuated by the tuning mechanism 14 including a worm gear arrangement 96 together with post members 98 with a deformable bellows arrangement 100 secured between the tuner mechanism and a movable support member 102.
  • a slot mode absorber assembly 104 is also axially translated adjacent to the ends of the slots 48 in the manner described in detail in the previously referenced pending United States patent application, Ser. No. 147,914.
  • the split ring tuner structure 106 is disposed within groove 108 formed in outer wall member 52.
  • FIG. 8 the detailed embodiment is shown with the broad tuning plate member 94 in two stages of operation to assist in an understanding of the invention. Components which are involved in movement are shown in the lefthand portion as being at rest. Components shown in the right-hand portion and designated by the suffix a" are in the tuned position.
  • the tuning structure 106 comprises split ring members and 107 anchored at one end adjacent window assembly 24 to the wall structure of groove 108.
  • the opposing ends 105' and 107 are coupled to actuator means 34 by reciprocating blade members 110 introduced through slot 112 in cavity resonator wall 1 vide for electrically isolating the ring member from the actuator.
  • the right-hand portion of the illustration represents the tuning ring members disposed entirely within groove 108 and, therefore, not perturbing the electric currents in the cavity resonant wall.
  • the left-hand portion represents the tuning ring members in full tuning position extending within the cavity resonator 50.
  • the point of maximum electric field intensity is approximately at the midpoint of wall 52.
  • the blade members in the position designated 110a therefore, represent the innermost position as determined by the actuating mechanism.
  • the split tuning ring members anchored at one end upon being deformed have a slight elliptical contour in the essentially circular cavity geometry at the midpoint region.
  • the split tuning ring members were fabricatedof a rigid metallic material such as, for example, the alloy comprising percent tantalum and 90 percent tungsten. Copper plating preserves the overall electrical circuit efficiencies of the cavity resonator structure.
  • Each of the tuning ring members for anx-band embodiment have a width of 0.050 inches and a height of 0.100 inches.
  • Ring damping structures 114 are provided a'pproximately 180 apart by housing members .116 each providing two tiers of dielectric rod members 118 adapted to contact opposing sides of tab portions 120. As shown in FIG. 6 the dielectric members 118 support the tab portions and thereby dampen any vibrations for good radial stability in dither tuning applications.
  • Reciprocating blade members 110 are actuated by means including pivoted cam follower members 122 now to be described with reference being directed to FIG. 7.
  • Each of the members 122 are supported by a central pivot 124 and surrounding ball bearing arrangement 126 secured to a housing member plate 128.
  • a rocker type motion will result with arms 13.0 and 132 providing a reciprocating motion about the central pivot axis.
  • Each of-the arms 130 and 132 carry a cam roller 134 and 136 adapted to contact adjacent bearing surfaces.
  • Follower member structure 138 includes tubular members 140 having piston type members 142 disposed at the inner end to contact reciprocating blade members 110 disposed within a notch 143.
  • Members 140 are provided with threaded bearing members 144 and are suitably adjusted to attain the desired stroke of the actuating means.
  • Actuation of the ring tuner structures is provided by vertically disposed linear control member 158 carrying onits inner end a bearing surface 160 which contact rollers 134.
  • the outer .end contacts eccentrically motor 164.
  • the right-hand portion represents the rest position with the tuning ring members supported wholely within the groove 108.
  • the right-hand portion represents the rest tuning position with the ring members disposed within the groove 108.
  • the linear control member 158 is shown in the downward thrust position and the bellows 152 are compressed.
  • the linear con- 7 trol member is in the upward thrust position with the bellows 152 extended to urge the reciprocating blade members to the position within the circular cavity resonator.
  • FIG. 9 the top view illustrates motor driven tuner assembly means 14 including eccentric bearing members 162 and 163 mounted on a shaft 166 which is actuated by a motor 164. All the components are supported on a plate member 168. The worm and gear arrangement 96 for driving the broad tuning plate member 94 is supported beneath plate 168 as indicated by the dashed lines in this view.
  • Bearing members 162 and 163 are eccentrically mounted on the shaft 166 so that, initially, bearing 162 picks up the linear control member 58 and upon completion of the tuning cycle the inner bearing member 163 contacts this linear control member.
  • the assembly is completed by a resolver means 170 controlled by shaft 166 to provide for direct readout of the fine tuning frequencies over a substantial portion of the tuning range.
  • a resolver-having direct frequency readout is readily available.
  • the position of the linear co'ntrol member 158 has been shown by dashed linesto indicate the relationship with eccentrically mounted bearing members 162 and 163.
  • Yoke arrangement 172 comprising scissors-type arm members 174 and 176 are united by a central pivot member 178
  • Eccentrically mounted bearing member180 is mounted on a shaft 182 driven by motor 184.
  • the displacement of bearing member 180 results in reciprocating movement of handles 186 and 188 attached to the outer ends of arms I74 and 176.
  • the inner ends of the reciprocating scissors-type structure 172 provides for reciprocating movement of mounted bearing'members 162 which are driven by a v the inner ends 190 and 192 of the arm members.
  • Piston actuators 194 and 196 suitably spring-loaded as by a member 204.
  • a second tuning ring member 206 may also be disposed within the groove 202. By providing for a wider dimension of the tuning ring 206 the tuning range capability may be doubled. A frequency range, therefore, of up to 400 MHz could be realized over desired frequency bands which is particularly useful in the dither tuning structures for frequency agility systems.
  • Another application of the disclosed tuning structure resides in automatic temperature compensation over an operating band of frequencies.
  • different metals are employed having different coefficients of expansion to reduce perturbation of resonant frequencies due to thermal absorption.
  • the thermal effects on the Q of the cavity can be effectively compensated for by expansion and contraction of the liquid which will move the tuning structure in and out of the cavity interior.
  • Such movement as herein described, varies the cavity resonance by introducing a dissymmetry in the electrical current bearing surfaces.
  • a crossed field device comprising: a cathode; an inner resonant system including a plurality of spaced anode members supported by a common boundary wall and defining therebetween cavity resonators surrounding said cathode to generate electromagnetic energy; an outer resonant system including a wall member defining with said boundary wall a coaxial cavity resonator adapted to be resonant over a frequency band;
  • a coaxial magnetron comprising:
  • anode member having a plurality of radially extending vane elements supported by a common boundary wall and defining therebetween cavity resonators;
  • an outer cylindrical wall member defining with said boundary wall and opposing end wall members a coaxial cavity resonator adapted to be resonant over a frequency band in a predetermined electric and magnetic field operating mode;
  • boundary wall having axially extending slots coupling energy between said anode and coaxial cavity resonators
  • tuning means comprise split ring members housed within a groove defined near the midpoint of the axial length of said outer wall member.
  • split ring members comprise a substantially rigid refractory conductive metallic material.
  • split ring members are fabricated of a tantalumtungsten alloy.

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US00223250A 1972-02-03 1972-02-03 Coaxial magnetron Expired - Lifetime US3731137A (en)

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US22325072A 1972-02-03 1972-02-03

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US (1) US3731137A (enrdf_load_stackoverflow)
JP (1) JPS5425793B2 (enrdf_load_stackoverflow)
CA (1) CA980006A (enrdf_load_stackoverflow)
FR (1) FR2169949B1 (enrdf_load_stackoverflow)
GB (1) GB1366473A (enrdf_load_stackoverflow)
IT (1) IT977188B (enrdf_load_stackoverflow)
NL (1) NL7301312A (enrdf_load_stackoverflow)

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3852638A (en) * 1974-03-14 1974-12-03 Varian Associates Dither tuned microwave tube
US3869638A (en) * 1973-11-02 1975-03-04 Varian Associates Triangular dither-tuned microwave tube
US3876903A (en) * 1974-03-22 1975-04-08 Varian Associates Dither tuned microwave tube
US3899715A (en) * 1972-06-22 1975-08-12 English Electric Valve Co Ltd Magnetron with rotatable tuning means
US3904919A (en) * 1974-05-06 1975-09-09 Varian Associates Rotary tuner for a circular electric mode crossed field tube
US3914644A (en) * 1974-04-18 1975-10-21 Varian Associates Rotary tuner for circular electric mode crossed field tube
US3932787A (en) * 1973-11-07 1976-01-13 E M I - Varian Limited Tunable coaxial magnetrons
US4131825A (en) * 1976-05-21 1978-12-26 U.S. Philips Corporation Ditherable and tunable magnetron comprising axially tuning and rotational tuning members
US4208597A (en) * 1978-06-22 1980-06-17 Westinghouse Electric Corp. Stator core cooling for dynamoelectric machines
EP0074173A1 (en) * 1981-09-08 1983-03-16 English Electric Valve Company Limited Improvements in or relating to magnetrons
FR2658950A1 (fr) * 1990-02-27 1991-08-30 Thomson Tubes Electroniques Tube hyperfrequence accordable en frequence.
US20050230387A1 (en) * 2004-04-14 2005-10-20 Michael Regan Insulated RF suppressor for industrial magnetrons
US20100066593A1 (en) * 2008-09-17 2010-03-18 Tetsuya Takashima Magnetron and radar apparatus
CN102208316A (zh) * 2010-03-31 2011-10-05 E2V技术（英国）有限公司 磁控管
CN108231509A (zh) * 2017-12-31 2018-06-29 中国电子科技集团公司第十二研究所 一种磁控管调谐装置及磁控管

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111965436B (zh) * 2020-08-27 2023-03-28 电子科技大学 非规则谐振腔内部电场强度标定系统及标定方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2466060A (en) * 1945-03-31 1949-04-05 Raytheon Mfg Co Electron discharge device
US3333148A (en) * 1966-12-12 1967-07-25 Westinghouse Electric Corp Ferrite tuned coaxial magnetron
US3414760A (en) * 1965-10-15 1968-12-03 Westinghouse Electric Corp A frequency diversity coaxial magnetron

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2466060A (en) * 1945-03-31 1949-04-05 Raytheon Mfg Co Electron discharge device
US3414760A (en) * 1965-10-15 1968-12-03 Westinghouse Electric Corp A frequency diversity coaxial magnetron
US3333148A (en) * 1966-12-12 1967-07-25 Westinghouse Electric Corp Ferrite tuned coaxial magnetron

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3899715A (en) * 1972-06-22 1975-08-12 English Electric Valve Co Ltd Magnetron with rotatable tuning means
US3869638A (en) * 1973-11-02 1975-03-04 Varian Associates Triangular dither-tuned microwave tube
US3932787A (en) * 1973-11-07 1976-01-13 E M I - Varian Limited Tunable coaxial magnetrons
US3852638A (en) * 1974-03-14 1974-12-03 Varian Associates Dither tuned microwave tube
US3876903A (en) * 1974-03-22 1975-04-08 Varian Associates Dither tuned microwave tube
US3914644A (en) * 1974-04-18 1975-10-21 Varian Associates Rotary tuner for circular electric mode crossed field tube
US3904919A (en) * 1974-05-06 1975-09-09 Varian Associates Rotary tuner for a circular electric mode crossed field tube
US4131825A (en) * 1976-05-21 1978-12-26 U.S. Philips Corporation Ditherable and tunable magnetron comprising axially tuning and rotational tuning members
US4208597A (en) * 1978-06-22 1980-06-17 Westinghouse Electric Corp. Stator core cooling for dynamoelectric machines
US4518932A (en) * 1981-09-08 1985-05-21 English Electric Valve Company, Ltd. Coaxial magnetron having cavity walls vibrated by tuning fork
EP0074173A1 (en) * 1981-09-08 1983-03-16 English Electric Valve Company Limited Improvements in or relating to magnetrons
FR2658950A1 (fr) * 1990-02-27 1991-08-30 Thomson Tubes Electroniques Tube hyperfrequence accordable en frequence.
EP0445009A1 (fr) * 1990-02-27 1991-09-04 Thomson Tubes Electroniques Tube hyperfréquence accordable en fréquence
US20050230387A1 (en) * 2004-04-14 2005-10-20 Michael Regan Insulated RF suppressor for industrial magnetrons
US20100066593A1 (en) * 2008-09-17 2010-03-18 Tetsuya Takashima Magnetron and radar apparatus
US8237608B2 (en) * 2008-09-17 2012-08-07 Furuno Electric Company Limited Magnetron and radar apparatus
CN102208316A (zh) * 2010-03-31 2011-10-05 E2V技术（英国）有限公司 磁控管
CN102208316B (zh) * 2010-03-31 2016-09-14 E2V技术（英国）有限公司 磁控管
CN108231509A (zh) * 2017-12-31 2018-06-29 中国电子科技集团公司第十二研究所 一种磁控管调谐装置及磁控管
CN108231509B (zh) * 2017-12-31 2024-03-22 中国电子科技集团公司第十二研究所 一种磁控管调谐装置及磁控管

Also Published As

Publication number Publication date
CA980006A (en) 1975-12-16
FR2169949B1 (enrdf_load_stackoverflow) 1976-09-10
JPS5425793B2 (enrdf_load_stackoverflow) 1979-08-30
FR2169949A1 (enrdf_load_stackoverflow) 1973-09-14
DE2305041B2 (de) 1977-07-07
DE2305041A1 (de) 1973-08-09
NL7301312A (enrdf_load_stackoverflow) 1973-08-07
IT977188B (it) 1974-09-10
JPS4888865A (enrdf_load_stackoverflow) 1973-11-21
GB1366473A (en) 1974-09-11

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