US2329777A

US2329777A - Electron discharge device

Info

Publication number: US2329777A
Application number: US417121A
Authority: US
Inventors: Leon S Nergaard
Original assignee: RCA Corp
Current assignee: RCA Corp
Priority date: 1941-10-30
Filing date: 1941-10-30
Publication date: 1943-09-21
Anticipated expiration: 1960-09-21

Description

Sept. 21, 19 3- L. s. NERGAARD v 2,329,777

ELECTRON DISCHARGE DEVICE Filed Oct. 50, 1941 v I-PI-i-M'In-I INVENTOR Zeon Jffierymzi W W W ATTORNEY Patented Sept. 21, 1943 7 Leon S. N ergaard', V Yerona, N Ji, assignor toiiadio V I Corporation'of America, a corporation of Dela ware Application Gctobcr so; 1941-, satel ite-[41 7, 121

V t claims; (01. zit-2&5

' My invention relates to'electron discharge de vices moreparticularly tosuch devices useful atultr-ahigh frequencies.

It is desirableto have-an out-putsystemhaving lowimpedance suitable-for operation with broadband circuits in the-ultra high frequency field that the power dissipating-'ability'of the output:

electrodes imposes nolimitation on the power output. i

It is, therefore,-an object of-my invention to I provide an improved electron discharge device suitable ion use athighfrequencies and capable of use with outputsystems having a low output impedance and suitable for operation with broad band circuits. 4 V It is another-object of-my invention to provide an electron discharge device suitable for use at high frequenciesandwhich avoids the use ofhigh frequency leads extending through the tube en- Velope, thus reducing high frequency losses Another object of my invention is to separate the current collector; and output electrodes so that the power dissipating ability, of the electrodesimposes no limitation on the power output. These; and other objects will appear hereinafter; The novel features which I believe to be characteristic of my invention are set forth Withparticularity in the appended claims, but th invention itself'will best be understood byireferenceto the following description taken in connection with the accompanying drawiiig'in which Figure lis aschematic longitudinal section of an electron discharge device and associated circuit made" according to my invention and'Figure 2 is a'sec-" tion taken alongthe line 2-'2 of Figure 1. V V l Briefly in an electrondischargedevice'made according to my invention, an elongated envelope" contains'at one end a cathode and modulating electrode for projecting a beam of electrons axially of the envelope and a collector electrode is mounted in the other end of the envelope. Adjacent the modulatin grid isa screen and ac-' celeratingelectrode and adjacent-the collector isa further screen and accelerating electrode; Positioned between the collector and 'modulating electrode and outside of the envelope are-anode segments 'having gaps lying-parallel to the longie tioned on opposite sides or t e" and line beiiig shieldd wittudinal axis of the? envelope and the "electron stream; Theariode segments are c'ciineted't a parallel transmission ime, t- -'anode;s e'g niits shielding com partrnentythe lifie being turned by p i ope'rl tuning means and energy being extracted by means ofa' loop coupled to the transmissionline; Magnetic means are provided which cooperate with the other electrodes; to'dtl'mihe thapatlf of the electrons in; the tube'l" Positioned centrally of the anode segments is" an e1 trodjfor causing eletrons-= pas-sing thiougii tli'e ni/elopeadjacent the node Segments"to descrilde-paths close to the envelope Wall and-the gaps betvvee'z'i the anode segments: v 1

Referring to the drawing; thelongated ez'i-' velope in has positioned at orie ndi th inui: rectly heated cathode Ii'proifidedWith heaterl'l and grid I Z for" Ifiodijlatilig the electron Strearri whenena, 1 I I cathode and grid: Mounted; atthe other end of the envelope is amnesia-c The output Iectroaesc'omprisc theanod segmen s IS -11 peso electron; stream between the cathode andcollector and on the outside of tlieei-ivelfif Adjacri'tt hegrid; is a cylindri cs1 eie-cu-cse I 4 operatedat a} sufliciently high voltage to preventform one]? a; virtual cathode arid consequent reflection of electrons within the cylinder. The cylinder-is longeiiough to prevent-coupling-betweri ma ma 'iZ and the output electrodes it and Ii.- Adjacent the col: lector is an electrodefli'which serves-as a sc een and sup iessor ier theeieet-roue le wl'iichcollects V.

the electrons; The collotoi is operated at a volt ge ust to collect an the electrons;

henc the cciieetor cart-be operated at a lower pote'ntialthah the output electrodes;

A roe mete-node H3 exteirds through"thecol lector l3 and suppressor lcl airiallfyof-ithe anode segments lfi andil 1 -ele"ot1"o'de-is'- ope-rated at approximately cathode potential and" operation of the tube reduces the axial or" lon'gi tudinal velocity of; the electrons and: provides a radial electric field sothat thezelectronsperform alarge number: of spiral orbits in the electric fieldofthe output-electrodes;

The magnetic iield. is electromagnet s- 2-6 and Z1 and the-field is ad: instead t9 sue ;,e,veli hat m for each orbit of the electrons passing through the output electrodes is equal to a period oft'he RsfF. grid voltage. The poteI-itial of the output electrodes is so adjusted that-the g rblts' bring-the electrons almost out tothe walloi the envelope VF; potential-is-" applied betwe'enth' provided by rneansof the I of the tube. The electromagnets also serve to keep the beam focused in passing through the shield M.

The input circuit may be provided by transmission line H! shorted by the tuning bar 29, the input voltage being coupled into the transmission line by means of the coupling loop 2|. The anode segments l6--ll are connected to the output transmission line comprising a pair of conductors 22 extending in a plane normal to the longitudinal axis of the tube envelope and shorted by means of the tuning member or disk 23, slidable on the conductors 22. The output circuit and output electrodes are enclosed within the shielding member 24 which shields the output from the input circuit and prevents undesired radiation, The shorting disc 23 serves to close the shielding compartment. The shielding compartment is provided with extensions 2G and 24", which enclose the cathode, grid and accelerator and the suppressor and collector posi tioned in opposite ends of the tube envelope. The output transmission line circuit may be coupledto output coupling loop 25 extending through the shorting member or disc into the shielded space.

Suitable sources of voltage 28 provided for the cathode heater, 29 forproviding a proper bias on the grid, and 3!! for supplying various voltages on the other electrodes are also provided. Suitable connections are made for applying a higher voltage to the output electrode segments [6 and I! and the shielding casing 24, and lower voltages to the suppressor l and collector it. The rod [8 is connected to the cathode so as to have cathode potential applied thereto during operation of the device.

Briefly the operation of the device is as follows: an R. F. signal is applied tothe transmission line l9, which causes an R. F. voltage to appear on the grid l2, which modulates the electron stream from the cathode ll. This modulated stream traverses the shielding electrode I4 and enters the space of the output electrode segments 16-41. In this space the electrons are slowed down by red i8 and directed outwardly by the radial electrostatic field between rod 18 and the segments. The axial magnetic field causes the electrons to perform spiral orbits, as in a magnetron, and give up energy to the out; put electrodes each time they cross the gaps or the gap field between the output electrode segments. The effective current from which the output electrodes obtain power is thus the, product of the beam current and the number, of spirals. Since this efiectivecurrent is large the tube is capable oi driving a low impedance load such as encountered in wide band transmission. After giving up their energy, electrons are collected by the collector l3.

While I have indicated the preferred embodiments of my invention of which I am now aware and have also indicated only one specific application for which my inventionmay be. employed, it will be apparent that my invention is by no means limited to the exact form illustrated or the use indicated, but that many variations may be made in the particular structure used and the purpose for which it is employed without departing from the scope of my invention as set forth in the appended claims.

What I claim as new is:

1. An electron discharge device having means for generating a modulated stream of electrons and an electrode for receiving the electrons in said stream, output electrode means comprising a plurality of segments surrounding the path of the stream and separated by gaps extending along the longitudinal axis of said stream, means for causing electrons of said stream to follow spiral orbital paths within the output electrode means a plurality of times past the gaps between said plurality of segments and then toward said collector, said last means comprising electromagnetic means for producing a magnetic field parallel to the longitudinal axis of said device and a rod positioned within and coaxial of said electrode segments and adapted to be maintained at substantially cathode potential during operation of said electron discharge device, and an output means comprising a conductor connected to one of said segments and another conductor connected to another of said segments, and means electrically joining the conductors remote from said segments.

2. An electron-discharge device having means for generating a modulated beam of electrons and a collector for receiving the electrons in said beam, output electrode means comprising a plurality of electrode segments surrounding the path of the beam and separated by gaps extending along the longitudinal axis of said beam, means for causing electrons of said beam, to follow spiral orbital paths within the output electrode means past the gaps between said plurality of segments and then toward said collector, and an output means comprising a conductor connected to one of said segments and another conductor, connected to another of said segments, and a shielding system surrounding said plurality of segments and said output means and meanselec trically joining the conductors remote from said segments and positioned Within said shield.

3. An electron discharge device having'means for generating a modulatedbeam of electrons and a collector for receiving the electrons in said beam, output electrode means comprising a plurality of electrode segments surrounding the path of the beam and separated by gaps extending along thelongitudinal axis of said beam, means for causing electrons of said beam to follow spiral orbital paths within the output electrode means a plurality of times past the gaps between said plurality of segments and then toward said collector, and an output means comprising a conductor connected to oneof said segments and another conductor connected to another of said segments, and a shielding system surrounding said plurality of segments and said output means, and conducting means slidable within said shielding system and electrically shorting said conductors and closing the shielding system around said output means.

l. An electron discharge device having an elongated envelope and containing means for directing a modulated beam of electrons longitudinally of said envelope, and a collector for col1ecting said electrons, output electrode means comprising a plurality of electrode segments surrounding and closely adjacent the outside of said, envelope, said segments being separated by gaps,

extending along the longitudinal axis of said beam and means for causing electrons from the cathode to follow, orbital paths within the space surrounded by said electrode segments.

5. An electron discharge device having an-elongated envelope and containingmeans for directing a modulated beam of electrons longitudinally of said envelope,

and a collector for collecting for causing, electrons from; the cathode to follow orbitalpathswithin. the space surrounded by. said electrode segments, said lastmeans comprising electromagnetic means for producingamagnetic field. parallel to the longitudinal axis of said envelope, and a rod positioned axially, ofrsaid electrode segmentsand adaptedrto be'maintained at substantially cathode potential during. operat-ion of said eleotron discharge device.

6; An: electron discharge device having an elongated envelope and: containing means for directing a modulated. beam of. electronsxlom gitudinally oisaid envelope, andca collector for collecting saidi electrons, output electrode means comprisinga. plurality. of electrode segments surrounding and closely adjacent the outside of said envelope, said segments being separated by gaps and means for causing electrons from the oathode to follow orbital paths Within the space surrounded by said electrode segments, said last means comprising electromagnetic means for producing a magnetic field parallel to the longitudinal axis of said envelope, and a rod positioned axially of said electrode segments and adapted to be maintained at substantially cathode potential during operation of said electron discharge device, and conducting members connected to different ones of said electrode segments, and means electrically connecting said conducting members remote from said electrode segments to provide an output transmission line.

7. An electron discharge device having an elongated envelope and containing means for directing a modulated beam of electrons longitudinally of said envelope, and a collector for collecting said electrons, output electrode means comprising a plurality of electrode segments surrounding and closely adjacent the outside of said envelope, said segments being separated by gaps and means for causing electrons from the oathode to follow orbital paths Within the space surrounded by said electrode segments, said last means comprising electromagnetic means for producing a magnetic field parallel to the longitudinal axis of said envelope, and a rod positioned axially of said electrode segments and adapted to be maintained at substantially cathode potential during operation of said electron discharge device, and conducting members connected to difierent ones of said electrode segments, and means electrically connecting said conducting members remote from said electrode segments to provide an output transmission line, and shielding means surrounding said electrode segments and said conducting members connected thereto for preventing radiation from said transmission line and coupling means associated with said transmission line.

8. An electron discharge device having an elongated envelope and having at one end a cathode and a grid for supplying a modulated beam of electrons longitudinally of said envelope, and a collector at the other end of said envelope for collecting said electrons, output electrode means comprising a plurality of electrode segments surrounding and closely adjacent the outside of said envelope, said segments being separated by gaps, and a shielding. electrode positioned adjacent the grid for shielding said cathode and grid from said electrode segments, and a second shielding electrode positioned between the, collectors and. said-electrode segments, and means foncausing e1e0trons:from: thecathode to! follow orbital; paths, within the space sure rounded; by said electrode; segments, said last meansv comprising; electromagnetic means for producing a magnetic field parallel to, the longi,- tudinal, axis: ofsaidgenyelope, and. a vrod posie tioned, axially of; said; electrode segments, and adaptedgtobe maintained, atsubstantially cathode potentiaL during; operation of: said electron, dis,-

charge, device, and: an output means connected to. saidaelectrode segments, and shielding; means surrounding saict electrode, segments and: out:

put means for, preventing: undesired radiation from. saidoutput means. 7

9;; An, electron discharge device having. an elongated: envelope containing a, cathode andcontroligridratone-iend of said envelope rorprovide ing astreainpi electrons longitudinally of said envelope, and a collector at the other end of said envelope, a tubular electrode positioned adjacent the control grid, and a second tubular electrode positioned adjacent the collector, an output electrode system surrounding said envelope between said tubular electrodes and including a plurality of anode segments separated by gaps extending along the longitudinal axis of said envelope, and a rod-like electrode extending axially of the envelope within the space surrounded by said anode segments and adapted to be maintained at cathode potential during operation of said electron discharge device, and means for providing a magnetic field parallel to and surrounding the rod-like electrode and an output means connected to said electrode segments.

10. An electron discharge device having an elongated envelope containing means at one end of said envelope for providing a stream of 6160-, trons longitudinally of said envelope, a control grid adjacent said means and a collector at the other end of said envelope, a tubular electrodepositioned adjacent the control grid, and a second tubular electrode positioned adjacent the collector, an output electrode system surrounding said envelope between said tubular electrodes and including a plurality of anode segments separated by gaps extending along the longitudinal axis of said envelope, and a rod-like electrode extending axially of the envelope within the space surrounded by said anode segments and adapted to be maintained at cathode potential during operation of said electron discharge device, and electromagnetic means surrounding said envelope for producing a magnetic field longitudinally of said envelope.

11. An electron discharge device having an elongated envelope containing means at one end of said-envelope for supplying a stream of electrons longitudinally of said envelope, a control grid adjacent said means and a collector at the other end of said envelope, a first tubular elecelectrode extending axially of the envelope with-' in the space surrounded by said, anode segments and adapted to be maintained at cathode potential during operation of said electron discharge device, and an output means connected I to said electrode segments, and electromagnetic means for producing a magnetic field longitudinally of said envelope, and a shielding structure surroundingsaid anode segments and said output means for preventing undesired radiation therefrom, and having extensions surrounding the envelope around the electron supplying means and first tubular electrode and around said collector and second tubular electrode.

12. An electron discharge device having an elongated envelope containing at one end a cathode and grid for supplying a modulated beam of electrons longitudinally of said envelope, and a collector at the other end of the envelope for collecting the electrons, output electrode means comprising aplurality of electrode segments surrounding the path of the electron stream between said grid and collector, and a shielding electrode positioned adjacent the grid for shielding said cathode and grid from said electrode segments, and a second shielding electrode positioned between the collector and said electrode segments, and means for causing electrons from the cathode to follow orbital paths within the space surrounded by said electrode segments, said last means comprising electromagnetic means for producing a magnetic field parallel to the longitudinal axis of the envelope and a rod positioned axially of the longitudinal axis and adapted to be maintained at substantially cathode potential during operation of said electron discharge device, and an output means connected to said electrode segments and shielding means surrounding said electrode segments and output means for preventing undesired radiation from said output circuit and extensions on said shielding means surrounding said cathode and grid and first shielding electrode and surrounding said second shielding electrode and said collector.

LEON S. NERGAARD.