US2765423A - Magnetron output coupler - Google Patents

Magnetron output coupler Download PDF

Info

Publication number
US2765423A
US2765423A US201471A US20147150A US2765423A US 2765423 A US2765423 A US 2765423A US 201471 A US201471 A US 201471A US 20147150 A US20147150 A US 20147150A US 2765423 A US2765423 A US 2765423A
Authority
US
United States
Prior art keywords
wave guide
magnetron
impedance
vanes
wave
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
US201471A
Other languages
English (en)
Inventor
Paul W Crapuchettes
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.)
Litton Industries Inc
Original Assignee
Litton Industries 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
Priority to BE521168D priority Critical patent/BE521168A/xx
Application filed by Litton Industries Inc filed Critical Litton Industries Inc
Priority to US201471A priority patent/US2765423A/en
Priority to DEI6852A priority patent/DE954803C/de
Priority to FR64930D priority patent/FR64930E/fr
Priority to CH328280D priority patent/CH328280A/fr
Priority to FR65481D priority patent/FR65481E/fr
Priority to FR65482D priority patent/FR65482E/fr
Priority to FR67505D priority patent/FR67505E/fr
Priority to FR69033D priority patent/FR69033E/fr
Application granted granted Critical
Publication of US2765423A publication Critical patent/US2765423A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H2/00—Networks using elements or techniques not provided for in groups H03H3/00 - H03H21/00
    • H03H2/005—Coupling circuits between transmission lines or antennas and transmitters, receivers or amplifiers
    • H03H2/006—Transmitter or amplifier output circuits
    • 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
    • H01J23/36—Coupling devices having distributed capacitance and inductance, structurally associated with the tube, for introducing or removing wave energy

Definitions

  • This invention relates to magnetron output couplers and more particularly to couplers for matching the impedance of magnetron resonators to an output wave guide.
  • the problem of securing the proper impedance matching between a magnetron and an output wave guide is one which has concerned the art for a considerable period of time.
  • the magnetron cavity resonators are generally of rather low impedance and the impedance decreases with increasing frequency of operation.
  • the impedance of a wave guide of the particular proportions is substantially constant. Accordingly, with increasing frequency of operation the problem of securing correct impedance match between the resonator and wave guide becomes increasingly difficult.
  • Several general forms of impedance matching have been proposed and used in the past.
  • the more satisfactory solution, particularly for tunable magnetrons is the provision of a so-called output ramp which comprises a set of plates or vanes within the end of the wave guide adjacent the magnetron.
  • vanes have their ends adjacent the magnetron relatively closely spaced and communicate with the resonator in the magnetron through an opening in the outer wall of the resonator. From this point on they taper exponentially to the wave guide walls. This type of coupling is quite satisfactory for frequencies wherein the opening from the magnetron is not too small. However, the initial loading in the magnetron must be decreased with increasing operating frequency so that this initial loading will vary inversely as the square root of the number of resonators divided by the wave length.
  • the resonator impedance may be in the order of 2.5 ohms whereas a 2x1 rectangular wave guide has a substantially constant impedance of about 300 ohms.
  • To achieve a match between these 'impedances by the tapered ramp requires a spacing at the magnetron output of .001 inch. This is so small that the heating of the magnetron with consequent distortion of parts and warping may completely upset the operation of the system.
  • a second type of system which has been used for impedance matching is the use of an effective single step one quarter wave impedance transformer.
  • Such an impedance transformer however is inherently narrow band, especially when coupling into a magnetron which has only 2.5 ohms impedance. Furthermore, such a coupling at these higher frequencies does not provide a sufficient attenuation of the adjacent operating modes of the magnetron to assure good operation in the 1r mode.
  • the impedance of the wave guide varies in precisely the wrong direction since it decreases with increase in frequency.
  • the quarter wave impedance transformer inverts the frequency variation and tends to increase the loading in undesired modes. However, as previously stated, this is not sufiicient in itself to produce the desired broad band matching in the output coupling circuits.
  • an impedance transformer unit comprising a pair of vanes within the wave guide and substantially in contact with the wave guide wall having their ends adjacent the cavity resonator spaced relatively closely together and extending rectilinearly at substantially constant spacing for a distance of substan' tially a quarter wave length at the mid operating frequency of the resonator and extending from the outer end of these rectilinear portions substantially exponentially to the resonator wall.
  • Figure 1 illustrates a cross-sectional view through a multi-cavity magnetron anode and the output wave guide coupler illustrating the construction of the output coupler in accordance with my invention.
  • Figure 2 is a cross-sectional view of a portion of Fig. 1 taken along the line 2-2 of Fig. l and Figure 3 is an illustration in section of a portion of the magnetron showing a modification of the output coupling slot shown in Fig. 1.
  • the magnetron may comprise a cathode I mounted centrally of a plurality of cavity resonators 2.
  • the resonators 2 may be constructed by providing a plurality of radial vanes 3 fastened at one end to the outer wall 4 of the magnetron.
  • a further body portion 5 is provided to support the resonator portions and to complete the tube.
  • the vanes 3 are normally strapped together at alternate vanes to secure the desired operation and reduce mode jump-- ing.
  • rings are not important to an understanding of the present invention they are omitted from the drawings in the interest of simplicity.
  • the energizing circuits in the magnetic field producing means are likewise omitted.
  • Wave guide 7 may be of any desired form and is illustrated herein as being rectangular in crosssection as will be apparent by reference to Fig. 2.
  • a glass or dielectric window 8 which may be sealed to support ring 9 and to the Wave guide 7 by means of an additional sealing ring, so that the interior of the wave guide may be evacuated.
  • a window is provided to permit electromagnetic waves to pass on the other output circuits.
  • impedance transformer vanes and 11 Within wave guide 7 are provided 2 impedance transformer vanes and 11. The inner ends 12 and 13 of the vanes 10 and 11 are spaced apart a small distance determined by the frequency of operation desired. This spacing need.
  • vanes a simple exponential transformer.
  • These portions 12 and 13 extend from the wall 4 of the magnetron a distance sub? stantially equal to the quarter wave length of the wave within the guide (kg). From the outer ends of portions 12 and 13 extend the exponentially tapered portions 14 and 15 respectively of vanes 10 and 11.
  • a small step or shoulder 16, 17 may be provided at the junction point between portions 12, 14; 13, 15 respectively. These shoulders however need not be provided but are used only as a matter of convenience in securing the desired end efiect on the quarter wave transformer section.
  • the portions 12, 13 constitute essentially a quarter wave length impedance transformer between the slot 6 and the wave guide 7 followed essentially in tandem by the exponential transformer defined by the portions 14 and 15 of vanes 10 and 11.
  • the slot 6 is directly in line with window 8. With such a construction it is found that stray electrons may be ejected through the opening and may puncture window 8. This may be avoided, for example by using a modified construction for the magnetron slot as shown in Fig. 3. in this illustration the slot 6 is made at an angle to the longitudinal axis of wave guide 7 so that electrons will tend to strike the wall of the Wave guide instead of impinging upon the output window.
  • the illustration of Fig. 3 is substantially similar to that of Fig. 1 except that here there is no shoulder provided between the portions 12, 14 and 13, 15 of the impedance transformer vanes 10 and 11.
  • An impedance matching coupler system comprising a low impedance resonator, a high impedance wave guide wherein the coupling is effected between said resonator and wave guide by an opening from the resonator into the wave uide, and a coupler designed to match the impedance of said resonator and wave guide over a given frequency band, comprising a pair of impedance transformer vanes within said Wave guide extending from diametrically opposed inner surfaces thereof toward one another, the adjacent edges of said vanes having a first portion providing a rectilinear substantially parallel spacing extending from said opening for a distance substantially a quarter wave length at the mid-operating frequency of said frequency band, and a second portion wherein the adjacent edges of said waves provide a gradually increasing spacing to said outer surfaces of said wave guide.
  • An impedance matching coupler according to claim 1 wherein said resonator is a cavity resonator of a magnetron, and wherein the Wave guide within which said impedance transformer vanes is mounted is evacuated.
  • An impedance matching coupler according to claim 3, wherein the opening between said resonator and said wave guide is made at an angle to the axis of said wave guide.
  • a magnetron comprising a wall portion, and a plurality of magnetron vanes extending from said wall to define separate magnetron cavity resonators surrounding a cathode, a wave guide sealed at one end to said wall, said wall portion having an opening communicating between one of said resonators and the interior of said wave guide, a pair of impedance transformer vanes mounted within said wave guide and extending from diametrically opposed surfaces of said wave guide toward each other, the inner edges of said vanes having a first portion substantial-ly a quarter wave length long at the operating frequency of said magnetron extending parallel to each other from said opening along said wave guide, and a second portion extending along said wave guide and gradually diverging in an exponential curve to said opposed surfaces.
  • a magnetron comprising a cylindrical wall portion, and a plurality of magnetron vanes extending radially inwardly from said wall to define separate magnetron cavity resonators surrounding a cathode, a wave guide sealed at one end to said wall and closed at its other end by a dielectric window, said wall portion having a longitudinal slot communicating between one of said resonators and the interior of said wave guide, a pair of impedance transformer vanes mounted within said wave guide and extending from diametrically opposed surfaces of said wave guide toward each other, the inner edges of said vanes having a first portion substantially a quarter wave length long at the operating frequency of said magnetron extending parallel to each other from said opening along said wave guide, and a second portion extending along said wave guide and gradually diverging in an exponential curve to said opposed surfaces.
  • a magnetron comprising a cylindrical wall portion, and a plurality of magnetron vanes extending radially inwardly from said wall to define separate magnetron cavity resonators surrounding a cathode, a wave guide sealed at one end to said wall and closed at its other end by a dielectric Window, said wall portion having a longitudinal slot communicating between one of said resonators and the interior of said wave guide, said slot being at an angle to the longitudinal axis of said wave guide, a pair of impedance transformer vanes mounted within said wave guide and extending from diametrically opposed surfaces of said wave guide toward each other, the inner edges of said vanes having a first portion substantially a quarter wave length long at the operating frequency of said rnagnetron extending parallel to each other from said opening along said wave guide, and a second portion extending along said wave guide and gradually diverging in an exponential curve to said opposed surfaces.

Landscapes

  • Microwave Tubes (AREA)
US201471A 1950-12-18 1950-12-18 Magnetron output coupler Expired - Lifetime US2765423A (en)

Priority Applications (9)

Application Number Priority Date Filing Date Title
BE521168D BE521168A (is") 1950-12-18
US201471A US2765423A (en) 1950-12-18 1950-12-18 Magnetron output coupler
DEI6852A DE954803C (de) 1950-12-18 1953-01-30 Anordnung zur Anpassung eines Resonators niedriger Impedanz an einen Hohlleiter mit hoher Impedanz
FR64930D FR64930E (fr) 1950-12-18 1953-05-28 Dispositif d'accord pour magnétron
CH328280D CH328280A (fr) 1950-12-18 1953-06-04 Dispositif haute fréquence comprenant une cavité résonnante et un guide d'ondes
FR65481D FR65481E (fr) 1950-12-18 1953-11-25 Dispositifs d'accord pour magnétron
FR65482D FR65482E (fr) 1950-12-18 1953-11-25 Dispositifs d'accord pour magnétron
FR67505D FR67505E (fr) 1950-12-18 1955-01-28 Dispositifs d'accord pour magnétron
FR69033D FR69033E (fr) 1950-12-18 1955-09-08 Dispositifs d'accord pour magnétron

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US201471A US2765423A (en) 1950-12-18 1950-12-18 Magnetron output coupler

Publications (1)

Publication Number Publication Date
US2765423A true US2765423A (en) 1956-10-02

Family

ID=22745951

Family Applications (1)

Application Number Title Priority Date Filing Date
US201471A Expired - Lifetime US2765423A (en) 1950-12-18 1950-12-18 Magnetron output coupler

Country Status (3)

Country Link
US (1) US2765423A (is")
BE (1) BE521168A (is")
CH (1) CH328280A (is")

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2805337A (en) * 1955-03-16 1957-09-03 British Thomson Houston Co Ltd Magnetron oscillators and their associated output circuits
US2886742A (en) * 1957-10-23 1959-05-12 Litton Ind Of California Broadband output coupler
US2887608A (en) * 1954-04-29 1959-05-19 Sperry Rand Corp Travelling wave tube
US2900561A (en) * 1953-12-15 1959-08-18 Bendix Aviat Corp Electron discharge device
US2963616A (en) * 1955-07-08 1960-12-06 Varian Associates Thermionic tube apparatus
US2967974A (en) * 1959-03-04 1961-01-10 Gen Electric Magnetron output coupler
DE1106427B (de) * 1957-03-30 1961-05-10 Philips Nv Auskopplungsanordnung fuer eine Magnetronroehre
US3104344A (en) * 1960-04-06 1963-09-17 Itt High power traveling wave tube
US5084651A (en) * 1987-10-29 1992-01-28 Farney George K Microwave tube with directional coupling of an input locking signal
US20110175691A1 (en) * 2008-01-31 2011-07-21 West Virginia University Compact Electromagnetic Plasma Ignition Device
US9551315B2 (en) 2008-01-31 2017-01-24 West Virginia University Quarter wave coaxial cavity igniter for combustion engines
US9873315B2 (en) 2014-04-08 2018-01-23 West Virginia University Dual signal coaxial cavity resonator plasma generation
US11725586B2 (en) 2017-12-20 2023-08-15 West Virginia University Board of Governors on behalf of West Virginia University Jet engine with plasma-assisted combustion

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2283935A (en) * 1938-04-29 1942-05-26 Bell Telephone Labor Inc Transmission, radiation, and reception of electromagnetic waves
US2412772A (en) * 1943-02-06 1946-12-17 Rca Corp Electron discharge device generator
US2429291A (en) * 1943-07-01 1947-10-21 Westinghouse Electric Corp Magnetron
US2455952A (en) * 1945-01-09 1948-12-14 Raytheon Mfg Co Magnetron
US2466922A (en) * 1946-02-12 1949-04-12 Bell Telephone Labor Inc Electron discharge device
US2473724A (en) * 1943-09-24 1949-06-21 Westinghouse Electric Corp Ultra high frequency coupler between contiguous ends of aligned wave guide sections
US2512901A (en) * 1945-11-01 1950-06-27 Charles V Litton Adjustable magnetron
US2555349A (en) * 1948-08-18 1951-06-05 Charles V Litton Variable ramp for magnetrons

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2283935A (en) * 1938-04-29 1942-05-26 Bell Telephone Labor Inc Transmission, radiation, and reception of electromagnetic waves
US2412772A (en) * 1943-02-06 1946-12-17 Rca Corp Electron discharge device generator
US2429291A (en) * 1943-07-01 1947-10-21 Westinghouse Electric Corp Magnetron
US2473724A (en) * 1943-09-24 1949-06-21 Westinghouse Electric Corp Ultra high frequency coupler between contiguous ends of aligned wave guide sections
US2455952A (en) * 1945-01-09 1948-12-14 Raytheon Mfg Co Magnetron
US2512901A (en) * 1945-11-01 1950-06-27 Charles V Litton Adjustable magnetron
US2466922A (en) * 1946-02-12 1949-04-12 Bell Telephone Labor Inc Electron discharge device
US2555349A (en) * 1948-08-18 1951-06-05 Charles V Litton Variable ramp for magnetrons

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2900561A (en) * 1953-12-15 1959-08-18 Bendix Aviat Corp Electron discharge device
US2887608A (en) * 1954-04-29 1959-05-19 Sperry Rand Corp Travelling wave tube
US2805337A (en) * 1955-03-16 1957-09-03 British Thomson Houston Co Ltd Magnetron oscillators and their associated output circuits
US2963616A (en) * 1955-07-08 1960-12-06 Varian Associates Thermionic tube apparatus
DE1106427B (de) * 1957-03-30 1961-05-10 Philips Nv Auskopplungsanordnung fuer eine Magnetronroehre
US2886742A (en) * 1957-10-23 1959-05-12 Litton Ind Of California Broadband output coupler
US2967974A (en) * 1959-03-04 1961-01-10 Gen Electric Magnetron output coupler
US3104344A (en) * 1960-04-06 1963-09-17 Itt High power traveling wave tube
US5084651A (en) * 1987-10-29 1992-01-28 Farney George K Microwave tube with directional coupling of an input locking signal
US20110175691A1 (en) * 2008-01-31 2011-07-21 West Virginia University Compact Electromagnetic Plasma Ignition Device
US8887683B2 (en) 2008-01-31 2014-11-18 Plasma Igniter LLC Compact electromagnetic plasma ignition device
US9551315B2 (en) 2008-01-31 2017-01-24 West Virginia University Quarter wave coaxial cavity igniter for combustion engines
WO2011127298A1 (en) * 2010-04-08 2011-10-13 West Virginia University Compact electromagnetic plasma ignition device
US9873315B2 (en) 2014-04-08 2018-01-23 West Virginia University Dual signal coaxial cavity resonator plasma generation
US11725586B2 (en) 2017-12-20 2023-08-15 West Virginia University Board of Governors on behalf of West Virginia University Jet engine with plasma-assisted combustion

Also Published As

Publication number Publication date
CH328280A (fr) 1958-02-28
BE521168A (is")

Similar Documents

Publication Publication Date Title
US2765423A (en) Magnetron output coupler
US2566087A (en) Tube of the magnetron type for ultra-short waves
US2523841A (en) Wave guide coupler
US2773213A (en) Electron beam tubes
US2673306A (en) Magnetron amplifier
GB617937A (en) Improvements in or relating to electron discharge devices for use on ultra high frequencies
US2802135A (en) Traveling wave electron tube
US3280362A (en) Electron discharge device with helixto-waveguide coupling means
US2786185A (en) Microwave output window
US2974252A (en) Low noise amplifier
US2806975A (en) Transition from bifilar helix to waveguide for backward wave oscillator
US2634383A (en) Cavity resonator high-frequency electron discharge device
US3576460A (en) Impedance match for periodic microwave circuits and tubes using same
US2462510A (en) Electron discharge device and associated circuit
US3448331A (en) Composite coaxial coupling device and coaxial window
GB1362832A (en) Coupled cavity slow wave circuit for microwave tubes
US2724090A (en) Electron discharge device output coupler
US3003118A (en) Synchronized regenerative amplifier
US2698421A (en) Wave guide seal and filter structure
GB1331911A (en) Highfrequency high power tubes particularly concerning their output devices
US2525468A (en) Ultra high frequency tube
US3104340A (en) Broadband klystron
GB1412034A (en) Resonant devices
US2768327A (en) Wave guide output circuit for a magnetron
US2758244A (en) Electron beam tubes