US2428554A - Ultra high frequency oscillation generator - Google Patents

Ultra high frequency oscillation generator Download PDF

Info

Publication number
US2428554A
US2428554A US467773A US46777342A US2428554A US 2428554 A US2428554 A US 2428554A US 467773 A US467773 A US 467773A US 46777342 A US46777342 A US 46777342A US 2428554 A US2428554 A US 2428554A
Authority
US
United States
Prior art keywords
cathode
field
frequency
anode
electrons
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
US467773A
Other languages
English (en)
Inventor
Cassen Benedict
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.)
Westinghouse Electric Corp
Original Assignee
Westinghouse Electric Corp
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 Westinghouse Electric Corp filed Critical Westinghouse Electric Corp
Priority to US467773A priority Critical patent/US2428554A/en
Priority to CH261493D priority patent/CH261493A/de
Priority to FR988432D priority patent/FR988432A/fr
Application granted granted Critical
Publication of US2428554A publication Critical patent/US2428554A/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
    • H01J35/00—X-ray tubes
    • H01J35/02—Details
    • H01J35/025—X-ray tubes with structurally associated circuit elements
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J25/00—Transit-time tubes, e.g. klystrons, travelling-wave tubes, magnetrons
    • H01J25/74—Tubes specially designed to act as transit-time diode oscillators, e.g. monotrons

Definitions

  • This invention relates to an oscillation generator, and more particularly to apparatus for generating ultra high-frequency oscillations.
  • Pulses of electrons are then liberated from the cathode 180 out of phase with the alternating field between the plate or anode and cathode in the anode-grid space, so that they do work upon or contribute energy to that field while abstracting energy from the constant potential field maintained between the anode and cathode.
  • An oscillator of this type is generally known as a density modulated oscillator for the grid controls the density distribution of electrons having the same velocity.
  • the time required for the electrons to pass from the cathode to the rid becomes appreciable in terms of a period of the alternating field. Because of this relatively high travel time, the electron pulse is no longer 180 out of phase with the alternating field between the anode and cathode when it reaches the grid-anode space and efiicient generation of oscillations is not effected.
  • the travel time may, of course, be reduced by decreasing the space between the elements of the triode. However, the necessary smaller spacing is impractical and requires too high a direct-current voltage on the plate to obtain sufficient power for satisfactory operation.
  • the Klystron oscillator is a velocity-modulated oscillator requiring apparatus for focusin an electron stream, the modulation being in the velocity distribution of the electrons as distinguished from the density modulation, and has a maximum theoretical efficiency of only fifty eight percent.
  • the magnetron also has certain disadvantages,
  • one of the principal disadvantage being the necessity for producing a magnetic field over a considerable volume of space especially for the delivery of high average power.
  • Another object of my invention is to provide a generator of ultra high-frequency oscillations in which the spacing of elements may be such as to afford a readily manufactured device.
  • a further object of my invention is to provide a generator of ultra high-frequency oscillations having a relatively high efficiency.
  • Still a further object of my invention is to provide a generator of ultra high-frequency oscillations in which the anode potential may be comparatively low while the generator delivers relatively high steady power.
  • I provide a density modulated cavity resonator oscillator.
  • the oscillator comprises a cavity resonator adapted to have an ultra high-frequency electromagnetic field therein and means responsive to the postive peaks of the high-frequency field for initiating passage of a group or pulse of electrons along a predetermined path through the highfrequency field, the length of the predetermined path relative tothe frequency of the field being such that the kinetic energy of the group of electrons is substantially zero at the end of the path.
  • the electron pulse enters the high-frequency field during the positive peaks of that field. While in the high-frequency field, energy is supplied to the electrons by a substantially constant direct current potential field. The electrons continue in the field through most, if not all, of the succeeding negative half period of the high-frequency field in which they deliver to the highirequency field substantially all of the energy derived from the direct current potential field.
  • the electron pulse may be provided by positioning an anode and a cathode so that they are subject to the high-frequency field within the cavity resonator.
  • the anode and cathode may form a portion of the walls of the resonator or they may be independent thereof.
  • a control element is positioned adjacent to the cathode and, because the practical spacings are small, the control member is preferably co-planar with the cathode.
  • a direct-current potential is applied between the anode and cathode and a small direct-current biasing potential is applied between the grid and cathode.
  • the performance of the oscillator is somewhat analogous to the class C vacuum tube oscillator.
  • the cathode is exposed to the direct current potential field between the anode and cathode and to the high-frequency field of the cavity resonator. During the positive half period of the high-frequency field, both of these fields tend to liberate electrons from the cathode.
  • the biasing potential on the control member is such that electrons are liberated from the oathode during the positive peak portion only of the high-frequency field. Consequently, pulses of electrons leave the cathode in phase with the high-frequency field and start out with that field doing work on them.
  • the electron pulse does not get very far before the field reverses and the energy which the electrons derive from the direct current potential field enables them to do Work on or contribute energy to the high-frequency field.
  • the anode is spaced from the cathode a distance such that the electron pulse is collected by the anode before the high-frequency field reverses again. Part of the energy thu's delivered to the highfrequency field by the electrons is employed in maintaining that field while the remainder of the energy may be extracted in any well-known manner and supplied to a load.
  • the spacing of the anode and cathode is definitely related to the frequency of the high-frequency field and the value of the direct current anodecathode potential.
  • an electron may be considered as starting from the cathode at a distance from the cathode $20 at the time 25:0.
  • the high-frequency field E is at its peak value and is superimposed upon a constant potential field F.
  • the electron should be collected at the anode at the instant that its kinetic energ becomes zero.
  • Equation 6 where A is wave length in centimeters and c is the velocity of light in centimeters per second. Then,
  • the distance between the anode and cathode is preferably such that the electron transit time is equal to /2 1r radians in terms of the angular frequency of the high-frequency field which is entirely practical in most cases. At extremely low wave lengths even this distance may become too small for practical purposes but satisfactory operation is obtainable if the distance is such that the electron transit time is /21r+21r71, radians, where n is a Whole number. Under such circumstances, the electron pulse is still collected at the anode when its kinetic energy is substantially zero.
  • FIGS 1, 2, 3 and 4 illustrate various embodiments of my invention
  • a hollow body or cavity resonator 5 having a shape similar to a doughnut and adapted to have an ultra high-frequency electromagnetic field therein has an anode 1 forming a portion of the wall thereof.
  • the cathode 9 is mounted on a. split tubular member I I and filament power is supplied from an alternating source I3 through an auxiliary transformer l5 whose secondary I1 is connected to different portions of the tubular member I I.
  • a control member I9 is mounted adjacent to the cathode and is made up of a wire ring within the cathode 9 and a second wire ring encircling the cathode.
  • the control rings H! are preferably substantially co-planar with the cathode 9 because of the small spacings and may be formed of tantalum o-r molybdenum wire.
  • the control rings l9 are connected to and mounted upon a second tubular member 23 separated from the first tubular member [I by an insulating material 25 such as glass.
  • a third tubular member 21 is connected to the main wall of the resonator 5 and is insulated from the second tubular member 23 by insulating material 29 which may also be glass.
  • the three tubular members II, 23 and 21 are of such length as to form a quarter Wave length resonant bypass for the high-frequency field so that a high-frequency potential does not appear between the control rings and cathode.
  • the glass insulation may also be extended to form a Vacuum tight enclosure.
  • the anode I is grounded and is connected through conductor 3
  • a direct current potential field is created between the anode l and the cathode 9.
  • the control rings iii are connected through conductor 39 to the junction point of the first potential source 33 and the resistor 35 so that a direct-current biasing potential consisting of the small constant potential of the second source 31 and the variable potential across the resistor. 35 appears between the control member and the cathode.
  • This biasing potential then varies in accordance with the amplitude of the high-frequency field within the resonator and is of such magnitude that electrons are liberated from the cathode during the p ak portions only of the positive half periods of the high-frequency field.
  • a pulse of electrons enters the high-frequency fieldduring a positive peak.
  • the high-frequency'field soon-reverses and the electrons contribute energy to the high-frequency field which they are deriving from the direct current potential field between the anode and cathode. Some of this energy is, used to maintain the high-frequency field and a coaxial output line 4
  • the anode and cathode are, of course, spaced so that the electrons are collected when their kinetic energy is substantially zero.
  • Fig. 1 The resonator disclosed in Fig. 1 is designed for operation in the first radial mode but Fig. 2 discloses a resonator designed for operation in the second radial mode.
  • the electromagnetic wave has a nodal point along the large diameter edge of the resonator and a maximum point in the middle thereof in Fig. 1, but in Fig. 2 the wave his nodal points at the large diameter edge of the resonator and another at the center thereof. Consequently, the cathode ring in Fig. 2 must be of a, sufficient diameter to be subject to the maximum point on the electromagnetic wave. Otherwise, the operation of Fig. 2 is identical with Fig. l and the same reference numerals are employed for similar elements.
  • FIG. 3 Another resonator design is shown in Fig. 3. This modification operates in the same manner as Fig. 1 and includes similar elements. However, the resonator is shaped differently to enable a generation of oscillations having larger Wave lengths with a compact apparatus.
  • Fig. 4 illustrates another embodiment of my invention in which the oscillations generated are employed to increase the speed of an electron stream for the production of X-rays.
  • the resonator 5 takes the form of a cylinder having a reentrant portion 43.
  • the cathode 9 forms apart of the wall of the cylinder, but the anode 45 is mounted on a support 41 within the cylinder and spaced the proper distance from the cathode.
  • a filament 49 is positioned at the inner end of the reentrant portion 43 of the resonator to projectelectrons upon a target 5! positioned opposite thereto.
  • a screen 53 is positioned adjacent to the filament 43 and is biased by an auxiliary source of potential 55.
  • the electron flow from the filament which is energized from source l3 through an auxiliary transformer 57, is blocked by the biasing potential until the electromagnetic potential exceeds a predetermined magnitude.
  • the electrons from thefilament 39 are accelerated and impinge upon the target 5
  • the generation of the high-frequency oscillations is, of course, accomplished .in the manner described herein'before.
  • An oscillation generator comprising a cavity resonator adapted to have. an ultrahigh-frequency electromagnetic field therein and means defining an electron path through said resonator comprising electron liberating means including a cathode mounted at one endof said path with asurface subject to said field and electron cola lecting means positioned at the other end of said path, said liberating means being responsive only to each positive peak of said field to initiate passage of a group of electrons from said cathode surface along saidpath, the length of said path within said resonator being equal to the distance over which substantially.
  • An oscillation generator comprising a cavity resonator adapted to have an 'ultra-high-frequency electromagnetic field therein and means defining an electron path through said resonator comprising electron liberating means including a cathode mounted at one end of said path with a surface subject to said field and electron collecting means positioned at the other end of said path, said liberating means being responsive only to each positive peak of said field to initiate passage of a group of electrons from said cathode surface along said path, the length of said path Within said resonator 'being equal to the distance over which substantially all of said group of electrons travel after initiation of the passage thereof in a predetermined time interval of the order of %1r+21rn radians in terms of angular frequency of said field, where n is any whole number or zero.
  • An oscillation generator comprising a cavity resonator adapted to have an ultra high-irequency electromagnetic field therein, means defining an electron path through.
  • said resonator including a cathode mounted at one end of said path and subject to said high-frequency field, and an anode positioned at the other end of said path, means connected to said anode and cathode for establishing a direct current potential field therebetween, and means connected to said cathode for establishing a biasing field adjacent to said cathode of a magnitude permitting liberation of electrons from said cathode only during the positive peaks of said high-frequency field whereby said liberated electrons move along said path from said cathode to said anode, the length of said path within said resonator being equal to the distance over which said electrons travel in a time period of the order of %7r+21rn radians in terms of the angular frequency of said highfrequency field, where n is a whole number or zero.
  • An oscillation generator comprising a cavity resonator adapted to have an ultra high-irequency electromagnetic field therein, means defining an electron path through said resonator including a cathode mounted at one end of the path and subject to said high-frequency field, and an anode positioned at the other end of said path, means connected to said anode and cathode for impressing a direct-current potential therebetween, a control member positioned adjacent to said cathode, and means connected to said control member and cathode for impressing a direct-current 'biasing potential there'oetween of a magnitude permitting liberation of electrons from said cathode only during the peakportion of the positive half-periods of said high-frequency field, the length of said path within said resonator being'equal to the distance over which said electrons travel in a time period of the order of j1r+21rn radians in'terms of the angular frequency of said high frequency field where n is a whole number
  • An oscillation generator comprising a cavity resonator adapted to have an ultra high-frequency electromagnetic field therein, means defining an electron path through said resonator including a cathode mounted at one end of the path and subject to said high-frequency field, and an anode positioned at the other end of said path, means connected to said anode and cathode for impressing a direct-current potential therebetween, and means connected to said cathode for establishing a biasing potential field adjacent to said cathode which varies according to the amplitude of said high-frequency field and is of a magnitude @permitting liberation of electrons from said cathode only during the peak portion of the positive half-periods of said high-frequency field, the length of said path within said resonator being equal to the distance over which said electrons travel in a time period of the order of %1r+21rn radians in terms of the angular frequency of said high frequency field where n is a whole number or zero.
  • An oscillation generator comprising a hollow body resonator adapted to have an ultra-high frequency electromagnetic field therein, means defining an electron path through said resonator including a cathode mounted at one end of said path and subject to said high-frequency field, and an anode positioned at the other end of said path, means connected to said anode and cathode for impressing a direct-current potential therebetween, a control member positioned adjacent to and substantially co-planar with said cathode, and means connected to said control member and cathode for impressing a biasing potential therebetween which varies according to variations in the amplitude of said field and is of a magnitude permitting liberation of electrons from said cathode only during the peak portion of the positive half-periods of said field whereby said liberated electrons move from said cathode to said anode, the length of said path within said resonator being equal to the distance over which the liberated electrons travel in a predetermined time interval after liberation thereof which is of the order
  • An oscillation generator comprising a cavity resonator adapted to have an ultra-high-frequency electromagnetic field therein, means defining an electron path within said resonator including a cathode mounted at one end of said path and subject to said high-frequency field, and an anode positioned at the other end of said path, means forming a first source of directcurrent potential connected in series with an impedance and means forming a second source of direc -current potential between said anode and cathode, said second source being opposite in polarity and smaller in magnitude than said first source with said first source being of a polarity tending to effect liberation of electrons from said cathode, a control member positioned adjacent to said cathode, circuit means connecting said impedance and second source between said control member and cathode to impress a biasing potential therebetween of a magnitude permitting liberation of electrons from said cathode only during the positive peaks of said highirequency field, whereby said liberated electrons move along said path from said cath

Landscapes

  • Microwave Tubes (AREA)
US467773A 1942-12-03 1942-12-03 Ultra high frequency oscillation generator Expired - Lifetime US2428554A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US467773A US2428554A (en) 1942-12-03 1942-12-03 Ultra high frequency oscillation generator
CH261493D CH261493A (de) 1942-12-03 1947-04-25 Ultrahochfrequenzgenerator.
FR988432D FR988432A (fr) 1942-12-03 1947-07-12 Oscillateur

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US467773A US2428554A (en) 1942-12-03 1942-12-03 Ultra high frequency oscillation generator

Publications (1)

Publication Number Publication Date
US2428554A true US2428554A (en) 1947-10-07

Family

ID=23857115

Family Applications (1)

Application Number Title Priority Date Filing Date
US467773A Expired - Lifetime US2428554A (en) 1942-12-03 1942-12-03 Ultra high frequency oscillation generator

Country Status (3)

Country Link
US (1) US2428554A (de)
CH (1) CH261493A (de)
FR (1) FR988432A (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3292031A (en) * 1963-05-27 1966-12-13 Trw Inc Anode capacitor and support for image converter camera tube
US4342066A (en) * 1978-05-16 1982-07-27 Kuelper Klaus Electrical condenser with a dielectric of gas under pressure

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2151765A (en) * 1936-03-05 1939-03-28 Telefunken Gmbh Device for generating electrical oscillations
US2167201A (en) * 1935-06-28 1939-07-25 Pintsch Julius Kg Electron tube
US2225447A (en) * 1939-09-13 1940-12-17 Rca Corp Electron discharge device
US2227372A (en) * 1938-07-21 1940-12-31 Univ Leland Stanford Junior Tunable efficient resonant circuit and use thereof
US2237878A (en) * 1939-02-02 1941-04-08 Rca Corp Electron discharge device
US2239421A (en) * 1940-03-09 1941-04-22 Rca Corp Electron discharge device
US2278210A (en) * 1940-07-05 1942-03-31 Bell Telephone Labor Inc Electron discharge device
US2398829A (en) * 1941-05-28 1946-04-23 Rca Corp Electron discharge device

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2167201A (en) * 1935-06-28 1939-07-25 Pintsch Julius Kg Electron tube
US2151765A (en) * 1936-03-05 1939-03-28 Telefunken Gmbh Device for generating electrical oscillations
US2227372A (en) * 1938-07-21 1940-12-31 Univ Leland Stanford Junior Tunable efficient resonant circuit and use thereof
US2237878A (en) * 1939-02-02 1941-04-08 Rca Corp Electron discharge device
US2225447A (en) * 1939-09-13 1940-12-17 Rca Corp Electron discharge device
US2239421A (en) * 1940-03-09 1941-04-22 Rca Corp Electron discharge device
US2278210A (en) * 1940-07-05 1942-03-31 Bell Telephone Labor Inc Electron discharge device
US2398829A (en) * 1941-05-28 1946-04-23 Rca Corp Electron discharge device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3292031A (en) * 1963-05-27 1966-12-13 Trw Inc Anode capacitor and support for image converter camera tube
US4342066A (en) * 1978-05-16 1982-07-27 Kuelper Klaus Electrical condenser with a dielectric of gas under pressure

Also Published As

Publication number Publication date
FR988432A (fr) 1951-08-27
CH261493A (de) 1949-05-15

Similar Documents

Publication Publication Date Title
US2278210A (en) Electron discharge device
US2190511A (en) Ultra short wave system
US2293151A (en) Resonant cavity device
US2276806A (en) High frequency apparatus
US2425657A (en) Short-wave apparatus
US2466063A (en) High-power high-frequency electron discharge apparatus
US2466064A (en) Velocity modulation apparatus
US2482769A (en) High-frequency apparatus
GB588293A (en) Improvements in or relating to ultra high frequency electron discharge apparatus
US2638561A (en) Cathode-ray oscillator tube
US2448527A (en) Cold cathode electron discharge device and circuits therefor
US2454094A (en) Electron discharge device for producing electric oscillations
US2329780A (en) Electron discharge device
US2428554A (en) Ultra high frequency oscillation generator
US2276320A (en) Centimeter wave device
US2487656A (en) Electron discharge device of the beam deflection type
US2462137A (en) Electron discharge device
USRE23277E (en) High-frequency resonator tube
US2254796A (en) Electron device using hollow resonator
US2466704A (en) Frequency multiplier apparatus
US2748277A (en) Magnetron noise generators
US2462869A (en) Electron discharge device
US2404078A (en) Electron discharge device
US2553566A (en) Phase modulated wave generator
US2196392A (en) Ultra high frequency oscillator system