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Патент USA US3023347

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Feb. 27, 1962
G. w. PRESTON
3,023,342
BEAM MODULATING DEVICES AND METHOD
Filed July 18, 1958
2 Sheets-Sheet 1.
INVENTOR. ‘A
G'ZE/V/V w EPA-“J70”
Feb- 27, 1962
e. w. PRESTON
3,023,342
BEAM MODULATING DEVICES AND METHOD
Filed July 18. 1958
2 Sheets-Sheet 2
"f '6
“
GLéW/l/ 14/.JNVENfbR.
Ream/v
BY Wigwam
United States Patent C
1.
$323,342
Patented Feb. '27, Mid?
1
2
3,023,342
sorbing and re?ecting action for modulating the amplitude
of the beam of particles produced by the device. The
BEAM MODULATING DEVICES AND METHOD
guide means is in the form of a magnetic ?eld for direct
Glenn W. Preston, Oreland, Pa., assignor to General
ing incident particles towards and re?ected particles from
Atronics Corporation, Bala-Cynwyd, Pa., a corporation
5 the plate member along different non-reciprocal paths.
of Pennsylvania
The charged particles may be negatively charged elec
Filed July 18, 1958, Ser. No. 749,555
trons in the form of a beam derived from the cathode of
7 Claims. (Cl. 315-12)
an electron gun.
The invention relates to particle selecting devices and
method, and more particularly devices and method for
modulating a beam of electrically charged particles.
Heretofore, beam modulating devices have been pro
An apertured element which electrical
ly shields the plate member is interposed between the
source of electrons and the plate member, while the mag
netic ?eld of the guide means de?ects the beam of elec
trons through the aperture of the element so that the
vided having the form of an electron gun which have
beam path is substantially perpendicular to the surface of
varied the intensity of a beam of electrons. However,
the plate member when proximate the plate member.
such modulation has also varied the point of focus for the 15 With the potential between the plate member and the ele
electrons and the forms of the devices have tended to re
ment controlled to provide an electric ?eld for regulating
duce the life of their electron emitting cathodes.
It is, therefore, a principal object of the invention to
the ratio of absorption to re?ection of electrons by the
plate member, the electrons re?ected by the plate member
provide a new and improved device and method for con
trollably selecting charged particles without substantially
varying the paths of the unselected particles.
Another object of the invention is to provide a newwand
improved device and method for modulating a beam of
form a beam which is de?ected by the magnetic ?eld of the
20 guide means through the aperture of the element and into
a non-reciprocal unde?ected path forming a predeter
' mined angle with the'unde?ected path of the beam of elec
trons from the source.
charged particles without substantially affecting their point
of focus.
’
i’
. ~
Another object of the invention is to provide a new and
improved beam modulating device and method providing
negative spherical aberration of its beam which may com
pensate for positive spherical aberration of the beam.
The method as applied to a beam of negatively charged
25
electron particles comprises subjecting the particles of said
beam to a magnetic ?eld for directing the particles along
the path into an electric ?eld parallel to the direction of
the electric vector, varying the amplitude and polarity of
the electric ?eld for controlling the proportions of elec
Another object of the invention is to provide a new and 30 trons rejected by the electric ?eld back into the magnetic
improved beam modulating device and method requiring
?eld, and utilizing said magnetic ?eld for forming a beam
low signal power and voltage for modulating the intensity
of the rejected electrons along a path in a predetermined
of its beam of electrons.
direction.
Another object of the invention is to provide a new
The foregoing and other ‘objects of the invention will
and improved device and method for modulating a beam 35 become more apparent as the following detailed descrip
tion of the invention is read in conjunction with the draw
its beam which are substantially independent of the total
ings, in which:
beam current.
FIGURE 1 is a side elevational view with portions
Another object of the invention is to provide an elec
broken away of a cathode ray tube embodying the inven
tron device for modulating a beam of charged particles 40 tion,
which has a low input capacitance to its beam modulating
FIGURE 2 is a side elevational view with portions
control electrode.
broken away of an ampli?er tube embodying the inven
Another object of the invention is to provide a new and
tion,
improved beam modulating device providing uniform
FIGURE 3 is a sectional view taken on line 3—3 of
cathode loading of its electron gun.
45 FIGURE 2,
Another object of the invention is to provide a new and
FIGURE 4 is a side elevational view of a signal com
of charged particles which provides optical properties of
improved beam modulating device having high trans
ductance.
Another object of the invention is to provide a new and
bining means embodying the invention,
FIGURE 5 is a partially diagrammatic view taken on
the line 5-—5 of FIGURE 4, and
improved beam modulating device responsive to high fre 50 FIGURE 6 is a diagrammatic representation of a kly
quency modulating signals and having good insulation be
stron embodying the invention.
tween input electrodes.
Like numerals designate like parts throughout the sev
Another object of the invention is to provide a beam
eral views.
modulating device and method which may readily be
Refer to FIGURE 1 which discloses a cathode ray tube
adapted for many varied uses.
55 10 embodying the invention. The cathode ray tube 10 has
‘Another object of the invention is to provide a new and
a glaSS envelope 12 with a ?rst portion 14 of circular cross
improved beam modulating device and method which is
‘ section having its end connected to a base 16 with con
highly e?icient in operation, provides low heat loss in its
necting pins 18, and a second portion 20 of circular cross
modulating operation, and has a high current and power
section. The ?rst and second portions 14, 20 are joined
capacity.
Another object of the invention is to provide a new and
improved beam modulating device which may be readily
60 with their axes at an angle of 90 degrees and forming an
intermediate cylindrical portion 22 symmetrically arranged
with its axis at an angle of 135 degrees with each of the
utilized as an ampli?er, a cathode ray tube, a klystron,
axes of the ?rst and second portions 14, 20 of the envelope
and a signal combining means, in appropriately modi?ed
12. The envelope 12 is also provided with a conical en
forms, having all the advantages stated above.
65 larged portion 24 at the end of the portion 20 and has
The above objects of the invention as well as the many
a substantially ?at face area portion-26. The tube It) has
other objects are attained ‘by providing a beam modulat
its cavity within the envelope 12 evacuated in the usual
ing device comprising a plate member for absorbing and
manner, and is sealed.
re?ecting incident charged particles of a beam, and guide
The ?rst portion 14 of the envelope 12 contains an elec
means for directing particles of the beam towards the plate 70 tron gun 28 for producing a beam 30 of electrons of sub
member. The plate member is provided with a connec
stantially uniform velocity along the axial path 32 to
tion for having its potential controlled to regulate its ab
wards the intermediate cylinder 22.
'
3,023,342
3
It is noted, that the electron gun 28in this case, may be
designed with a slightly diverging electric ?eld at its emit
axially along the portion 20 of the envelope 12 towards
the enlarged end portion 24.
ting surface for insuring increased life and dependability,
whereas the ?eld is usually converging, overloading the
central portion of the cathode, in prior art beam modulat
It is noted that the boundaries of the magnetic ?eld in
the region 34 transversed by the electrons of the beam
30 are substantially plane and parallel to the intercepting
ing devices.
surface of the plate member 46 and oriented at an angle
of substantially 45 degrees to the direction of the unde
?ected beams 30 and 68. This angle of the boundary of
When the electrons of the beam‘ enter the region 34 of
the cylinder 22, they are de?ected to the left along a
curved path 36 by the ?eld produced by the electric coil
the magnetic ?eld within the region 34 acts to broaden
38 positioned on the outside of the cylinder 22 about the 10 the beam 30 as it enters the magnetic ?eld. This is due to
the fact that the electrons in the beam to the left are
region 34 and proximate to the ?rst and second portions
acted upon earlier than the electrons to their right along
the cross section of the beam. The broadening of the
beam serves to decrease the electron density of the beam,
14, 20 of the envelope 12.
After being de?ected, the beam 30 of electrons proceeds
along a path 40 through an aperture 42 in a shielding
element 44 and towards a plate member 46.
The shielding element 44 has the form of a cylindrical
body with a wall 48 and a plane base portion 50 having
15
and thereby, increase the e?iciency of the're?ecting opera
tion of the device. It is noted that, since the beam is
doubled back upon itself along the paths 40, 64, this
tends to maintain the beam density at a value substantially
equal to that of the beam along the path 32.
As the beam is de?ected along path 66 and leaves the
adjusting means 52. In this manner, the base 50 of the 20
magnetic ?eld in the region 34 it is directed into a path
element 44 is interposed along the path 40 of the beam 30
68 which is also at an angle of substantially of 45 degrees
of electrons between the magnetic ?eld in the region 34
the aperture 42 at its center. The shielding element 44
is maintained in position within the cylinder 22 by spring
with the boundary of the magnetic ?eld. This has the
and the plate member 46. The shielding element 44 is
effect of sharpening or narrowing the beam and increasing
made of electrically conducting material which is pervious
to magnetic lines of ?ux.
25 its density to a value that is substantially the same as that
‘ The plate member 46 is secured within the cylinder 22
at its bottom 54 in parallel spaced relation to the base 50
of the shielding element 44. The shielding element 44 is
connected to a lead 56 which, for example, may receive a
positive potential of about 400 to 4000 volts with respect 30
to the cathode of the electron gun 28. The plate member
of the beam 30 along the path 32 when the beam is un
modulated. As previously noted, however, the beam 70'
may have introduced therein negative spherical aberra
tion due to the re?ecting process undergone by its
electrons.
The proportion of electrons absorbed to those rejected
46 is connected to a lead 58 which may be maintained at
or re?ected is a function of the potential of the plate
substantially cathode potential and varied positively and
member 46. Therefore, as the modulating signal varies
the voltage on the plate member 46 the intensity of the
negatively by a modulating voltage signal. In this con
nection, the magnetic ?eld produced by the coil 38, for 35 beam 70 formed of re?ected electrons varies in a corre
example, may be in the order of 100 to 500 gausses to
sponding manner. Since the incident electrons move per
provide the required de?ection for the beam. The change
pendicular to the intercepting surface 62 of the plate
in intensity of the electric ?eld between the shielding
member 46 the electrons which impinge upon and are
element 44 and plate member 46 produced by the modu
absorbed by the member 46 have lost most of their en
lating voltage‘ signal on lead 58 is effectively shielded by 40 ergy, thereby minimizing the heat produced in the mem
the element 44 from the other regions within the envelope
ber 46, and the energy and power required to operate the
12 of the cathode ray tube 10.
- As the beam of electrodes proceed toward the member
device.
It is also noted that the electrons which are re
?ected or repelled by the electric ?eld 60 do not lose any
of their energy, which is regained by their passage in the
46 along the path 40 through the aperture 42 of the ele
ment 44, they enter the region 60 of the electric ?eld be 45 opposite direction through the electric ?eld in the region
tween the shielding element 44 and the plate member 46.
60.
The lines of force of the electric ?eld produced by this
Since this device does not utilize the grids commonly
con?guration are substantially parallel and perpendicular
used in electron devices, the partition noise resulting
to the plate member 46. The electrons of the beam upon
therefrom is eliminated, thereby increasing the signal to
entering the region 60 are accelerated or decelerated in 50 noise ratio obtainable. This structure also provides a
accordance with the polarity of the electric ?eld.
high transconductance for the tube 10 as well as a low
In operation, the polarity of the electric ?eld is ad
capacitance to the input lead 58 of the plate control mem
justed to retard and decelerate the incident electrons in
ber 46 receiving the beam modulating signal, because of
their motion towards the intercepting surface 62 of the
the relatively large separation between the base 50 and
plate member. 7 It is also noted that the path 40 of the 55 the plate member 46.
beam of electrons is substantially parallel to the electric
The modulating device also provides an electron beam
?eld vector so that there is no component of lateral accel
70 which, while having its amplitude modulated, does not
eration or velocity and the path 40 is substantially per
vary its focal point. The re?ecting method of the struc
pendicular to the intercepting surface 62 of the plate
ture also provides a negative spherical aberration which
member 46. If the voltage on the plate member 46 is 60 may compensate for the positive spherical aberration
su?iciently above cathode potential, most of the electrons
usually present due to the focusing and other means of
in the path 40 will reach the plate member 46 and be ab
the cathode ray tube 10. The optical properties of the
sorbed. However, as the potential of the plate member
beam are, thus, independent of the total current of the
46 is reduced a decreasing number of electrons will reach
beam. This is a very highly desirable property.
the plate member 46, while the remaining electrons will 65
As the beam 70 of electrons proceeds along its path 68,
have their velocity reversed before they reach the plate
it‘passes through an aperture 72 in the transverse wall
member 46 and be rejected from the region 60 along a
portion 74 of a focusing cylinder 76 positioned within
path 64 coincident with the path 40. The electrons will
the portion 20 of the envelope 12. The beam 70 passes
move along the path 64 through the aperture 42 and into
through the focusing cylinder 76 and between the hori
the region 34 of the magnetic ?eld produced by the coil 70 zontal and vertical de?ecting plates '78, 80. The de?ect
38. At this time, since the direction of the electrons along
ing plates 78, 80 provide for horizontal and vertical de
their path 64 is reversed from that along the path 40, the
?ection of the beam 70 which proceeds towards the face?
magnetic ?eld de?ects the electrons along a non-reciprocal
portion 26 of the cathode ray tube 10 and impinges upon
curved path 66 into the unde?ected path 68. The rejected
its electron collecting surface.
electrons form a beam 70 along the path 68 proceeding 75
In summary, the tube 10 produces a beam of electrons
3,023,342
.
5
30, preferably by providing a diverging electric ?eld at
of the device 10 of FIGURE 1. A beam 94 formed of
the emitting surface of the cathode. The beam 30
electrons emitted from the electron gun 92 proceeds along
proceeds towards the region 34 of the cylinder 22, where
the path 96 until it enters the magnetic ?eld produced by
it is broadened at the boundary of the magnetic ?eld of
the magnetic coil 120 in the region 138 within the en
coil 38 and de?ected to the left along the circular path
velope 84.
36 into path 40. The path 40‘ proceeds through the
Since the beam 94 enters the magnetic ?eld at its
aperture 42 of the shielding element 44 into the electric
boundary at an angle differing from 90 degrees, the beam
?eld of the region 60. Depending upon the potential
is broadened. The electrons within the magnetic ?eld,
difference and the resulting electric ?eld produced by the
since their path is substantially perpendicular to the lines
plate member 46 and the shielding element 44, a greater 10 of magnetic ?ux, are de?ected along substantially circular
or smaller’ proportion of electrons will be absorbed by
paths 140 and into substantially linear paths 142 as they
the plate 46, with the remaining electrons being rejected
emerge from the region 138. When the beam of elec
or re?ected back through the aperture 42 along the
trons along the path 142 enter the region 118 of magnetic
path 64. When the electrons move through the magnetic
?ux produced by the magnet 112, they are again de?ected
?eld in the region 34 they are de?ected along the non 15 along substantially circular paths 144 and through the
reciprocal circular path 66 into the path 68. The beam
aperture 106 towards the intercepting surface of the plate
is narrowed at the boundary as it emerges from the mag
netic ?eld. The electrons along the path 68 form a beam
member 134.
The ‘beam of electrons, as it approaches the plate mem
which is modulated in intensity and proceeds to the right
ber 134, proceeds along the path which is substantially
making an angle of 90 degrees with the beam of incident 20 perpendicular to the intercepting surface of the member .
electrons along the path 32.
134. The region 146 between the deformed portion 104
The electrons approach the plate member 46 substan
of the shielding element 102 and the plate member 134 is
tially perpendicular to its intercepting surface 62, there
provided with a retarding electric'?eld of varying intensity
by, minimizing the energy dissipated by the impinging
controlled by the relative potentials of the shielding ele
electrons, While the re?ected or rejected electrons regain 25 ment 102 and the plate member 134. As an example, the
their initial kinetic energy and are focused at the same
potential of the shielding element 102 may be maintained
point, which is not dependent upon the beam intensity or
at a positive voltage with respect to the cathode of the
the modulating signal. The shielding element 44 serves
electron gun 92 of about 20 to 400 volts for use of the
to shield the modulating electric ?eld from the remaining
tube device 82 as an ampli?er, while the plate member
portions of the envelope 12.
30 134 may be maintained at substantially the same potential
The modulated beam 70 proceeds along the portion 20
of the envelope 12 being ‘focused by the cylinder 76 and
as the cathode of the electron gun 92 and varied about
tube 82 which ‘is a modi?cation of the device shown in
FIGURE 1. The electron tube 82 has a glass envelope
84 providing an evacuated cavity. The left end portion
86 of the envelope 84 has its end connected with a base
The re?ected or repulsed electrons pass along a path sub
stantially perpendicular to and in a direction away from
this potential by a beam modulating signal delivered to
de?ected by the plates 78, 80 in the usual manner. The
the terminal of a lead 136 for varying the intensity of the
negative spherical aberration produced by the beam modu
electron beam re?ected by the plate member 134.
lating structure within the cylinder 22, compensates for 35
As explained in connection with the tube device 10, the
and counteracts the positive spherical aberration produced
proportion of the re?ected or rejected electrons, which
by the focusing cylinder 76.
are not absorbed by the plate member 134, is controlled
Refer to FIGURES 2 and 3 which illustrate an electron
by the potential signal delivered to the plate member 134.
the plate member 134, through the aperture 106, then
along a substantially circular path 148 in the region 118
of magnetic ?ux. Since the direction of the repulsed elec
88 with pins 90. ,A cathode ray gun 92 is positioned
within the end 86 of the envelope 84 for producing a
tron is opposite‘to the direction of the motion of the elec
beam of electrons 94 which proceeds along an axial path
trons
incident to the plate member 134, the magnetic ?eld
45
96 towards the second end 98 of the envelope 84.
in
the
region 118 ‘acts to de?ect the electrons to the right
i The central portion 100 is provided with a cylindrical
into a non-reciprocal path 150. The electrons move to
metallic shielding element 102 which is axially aligned
the right along the path 150 until they enter the magnetic
with the axis of the envelope 84'. A portion of the circular
?eld
produced within the shielding element 102 by the
wall of the shielding element 102 is deformed to provide a
magnetic
coil 122. This ?eld, which has its lines of ?ux
?attened region 104 having a central aperture 106. The
substantially perpendicular to the velocity of the electron
right end of the shielding element 102 is enclosed by a
beam, de?ects its electrons along substantially circular.
base. portion 108 having a central aperture 110.
paths
152 into an unde?ected path 154 which can be
The central portion 100 of the envelope 102 receives
aligned with or made substantially parallel to the direc
about it a magnet 112 having poles 114, 116 providing a
of the beam of electrons 94 as emitted by the elec
?eld therebetween shown within the dotted region 118 55 tion
tron gun 92.
with lines of flux substantially parallel to the plane of the
When the beam of electrons along the path 152
deformed portion 104 of the shielding element 102. The
emerges from the region 156, its path 154 forms an angle
magnetic ?cldin the region 118 is symmetrically posi
with the boundary of the magnetic ?eld which operates
tioned on each side of the aperture 106 with its ?ux lines
60 to narrow or sharpen the beam providing a cross sec
perpendicular to the plane of FIGURE 2.
tion which is substantially similar to that of the original
A pair of magnetic coils 120, 122 are symmetrically
beam 94 emerging from the electron gun 92.
positioned about the outside of the envelope 12 at its cen
In the tube device 82 each of the magnetic ?elds pro~
tral portion 100‘ on each side of the magnet 112 with
duced by the magnet 112, and magnetic coils 120, 122
their bottom ends 124, 126 spaced further apart than 65 may
have a magnetic ?eld intensity of approximately 50
their top ends 125, 127.
V
p
‘ Collecting plate 128 is positioned at the end of the por
tion 98 of the envelope 84 in spaced relation to the base
_108 of the shielding element 102. The collecting plate
‘ gausses to provide the required de?ection of the beam of
electrons.
. As the beam passes along its path 154 it emerges from
the region within the shielding element 102 through the
128 is connected with a lead 130 which may be returned 70 aperture 110 in the base portion 108 of the cylindrical
to ground potential through a load 132.
shielding element 102. The beam continues along its
A plate member 134 is positioned outside the shielding
path 154 until it impinges upon the collector plate 128.
element 102 in spaced relation to its deformed portion
As the. intensity of the current of electrons received by
104 and is connected externally to a lead 136. ‘
the collector plate 128 varies a signal output is provided
The tube device 82 operates in a manner similar to that 75 across the load 1.32.
‘
3,023,342
8
7
The shielding element 170 is provided with a plurality
of apertures 196, 198, 200 and 2.02 each respectively
positioned proximate the cathode 176, plate members 180,
Thus, the electron tube device v82 may be used as an
amplifying device by delivering an input signal to the
lead 136 of the plate member 134 which in turn modu
lates the intensity of the beam of electrons which elec
trons are delivered to the collector plate 128 producing
182 and the collector plate 184.
an output signal. The tube device, in this manner, may
be used for voltage or current ampli?cation.
As previously noted many advantages are provided by
this structure because of the low input capacitance and
high transconductance achieved by the device. The de 10
vice also provides high e?‘iciency with low power dissipa
tion, high reliability and long tube life.
Instead of providing a collector plate 128, the device
82 may be provided with focusing and de?ecting means
A substantially uniform magnetic ?eld is produced ‘in
the region 204 inside the shielding element 170. The
lines of ?ux of the magnetic ?eld are parallel to the cylin
drical axis of the shielding element 170 and perpendicular
to the plane of FIGURE 5. The magnetic ?eld is pro
duced by a magnet 206 having the faces of its poles 208,
210 respectively parallel and proximate to the top and
bottom walls 166, 168 of the envelope 162.
In operation, the electrons emitted by the heated
cathode 176 are accelerated towards the shielding element
and a ?uorescent screen to form an in line type of cathode 15 170 because of its higher potential. ' The'elect'rons which
ray tube instead of the bent cathode ray tube 10 shown
in FIGURE 1. Of course the modulated beam pro
duced by the device may be utilized to form many other
electronic devices having many if not all of the enumer
ated advantages.
pass through the aperture 196 in the element 178 form
a beam of electrons 212 which are de?ected into a sub
stantially curved path 214 by the magnetic ?eld within
the region 204. The path 214 is substantially circular
20 since the velocities of the electrons are perpendicular to
The invention may be adapted to utilize charged par
tioles other than electrons embodying the basic features
disclosed herein. For example, the method of the inven
tion may be applied by subjecting a charged particle or
a beam of charged particles to a magnetic ?eld for de 25
?ecting the particles along a predetermined path into
an electric vector ?eld, varying the vector intensity of
the electric ?eld for controlling the proportion of particles
rejected by the electric ?eld, and forming the electrons
the lines of magnetic ?ux. The electrons along the path
214 pass through the aperture 198 of the shielding ele
ment 170 towards the plate member 180 in a direction
perpendicular to its electron intercepting surface.
As previously explained in connection with the devices
10 and 82 the electric ?eld produced between the shield
ing element 170 and the plate member 180 acts upon the
electrons to decelerate them. As the modulating signal
delivered to the terminal 186 varies the potential of the
rejected by the electric ?eld into a beam of particles. 30 plate member 180 about substantially ground potential,
the proportion of electrons repelled and not absorbed by
The beam of rejected particles may also be further de
the member 180 is correspondingly controlled. The
?ected by a magnetic ?eld into a desired non-reciprocal
repelled or re?ected electrons, like the incident electrons,
path. The intensity vector of the electric ?eld is directed
move substantially parallel to the lines of force of the
parallel to the path of the particles for re?ecting or reject
ing the panticles from the electric ?eld along a path sub- ‘ electric ?eld and pass back through the aperture 198
forming a beam 216 with a modulated amplitude within
stantially identical in direction to the path of the incident
the region 204 of the device 160.
particles. The method of the invention, it will be noted,
The magnetic ?eld within the region 2% acts upon
may readily be applied to removing or absorbing particles
the beam 216 to de?ect the electrons along a non-recip
for modulating the intensity of the beam comprising posi
tively or negatively charged particles having a mass great 40 rocal substantially circular path 218 which proceeds to
the right and causes the electrons to pass through the
er or smaller than that of the electron.
aperture 200 into the ‘electric ?eld between the shielding
Refer to FIGURES 4 and 5 which shows a signal com
element 170 and the plate member 182. As before the
bining means 160 comprising a substantially cylindrical
variation of potential of the plate member 182 by the ap
glass envelope 16-2 having a cylindrical wall 164 and top
and bottom walls 166, 168. The envelope 162 has its 45 plication of an input signal to its terminal 188 varies
chamber evacuated and sealed in the usual manner.
A cylindrical shielding element 170 is positioned by
a plurality of radially extending spacing means 172 with
in the envelope 162 with its axis aligned with the axis
the electric ?eld acting upon the electrons. In this man
ner, the ratio of electrons which are absorbed to those
re?ected is controlled. The re?ected electrons pass back.
through the aperture 200 forming a beam of electrons.
of the envelope 162. The spacing means may be in the 50 220 in the magnetic ?eld of the central region 204 of the
device 160. The beam 220, however, has an amplitude
form of springs to adjust for relative expansion and con
which is further modulated by the signal delivered to
traction of the envelope 162 and shielding element 170.
The spacing means 172 also provides a peripherial an
nular region 174 between the side wall 164 of the en
the terminal 188.
-
The beam 220 is de?ected by the magnetic ?eld along
velope 162 and the shielding element 170. A cathode 55 a non-reciprocal circular path 222 and through the aper
ture 202 toward the collector plate 184. Since the col
176 is positioned within the annular region 174, and is
lector plate 184 is maintained at a potential which is sub
associated with a heating element 178. The cathode 176
stantially above ground potential, it absorbs substan
may be returned to ground potential while the heating
element 178 may be energized by an appropriate cur
rent source.
tially all of the electrons of the beam 220. This pro
duces
an output signal across the load 194. The output
60
signal produced is related to the amplitude of the beam
A plurality of plate members 180, 182, and an elec
220 which has been appropriately modulated by the
tron collecting plate 184 are angularly positioned in
several input signal delivered to the terminals 186 and 188.
spaced relationship within the annular region 174 of
Although the device 160 has been described with two
the envelope 162. The members 180 and 182 may be
Joined to respective external terminals 186, 188 which 65 plate members, many such members may be arranged
within the annular region 174 for combining a plurality
are each adapted to receive input signals, while the col
of input signals. In order to reduce the magnetic ?eld
lector plate 184 is connected to an external lead 190'
necessary to sharply de?ect the beam of electrons, the
which is joined to a terminal 192 maintained at an ap
plate members may be spaced about the periphery so that
propriate potential through a load 194. A lead 195
connects the shielding element 170 to a terminal 197 for 70 the beam passes from one plate member to a non-adjacent '
plate member and makes more than one revolution about
being maintained at an appropriate voltage which is
the central region 204 before it impinges upon the col
positive with respect to the cathode 176. For example,
lector plate. By this means a highly compact signal
the device may be operated with a positive potential of
combining device may be provided which is adapted to
100 to 500 volts on 1116 terminal 197 of the shielding ele
ment 170.
"
'
75 receive a plurality of signals.
_ lI
3,023,342
10
As noted in connection with the devices 10 and 82,
the signal combining device 160 has a low input signal
What is claimed is:
1. A system for modulating the intensity of a beam of
capacitance and provides good insulation between input
electrically charged particles, said system comprising:
electrodes while using one magnetic ?eld for particle de
means for projecting said beam along a predetermined
path; means for magnetically de?ecting said beam into a
different path at an angle to said predetermined path; and
means for re?ecting along a reciprocal of said different
path a fraction of the particles in said beam while ab
?ection.
Such devices can be especially useful in con
receive a plurality of input signals.
The FIGURE 6 is a diagrammatic view of a klystron
device 224 embodying the invention. The device 224
comprises a tubular envelope 226 having a first end 223
sorbing the remainder of said particles.
and a second 230. The ?rst end 228 of the device 224 10
2. The system of claim 1 further characterized in that
is substantially similar to the beam modulating device 82
said re?ecting means comprises means for establishing in
of FIGURE 2 except that the distance between the shield
said different path an electric ?eld having lines of force
ing element 102 and the collector plate 231 is greatly en
parallel to said last-named path and of such polarity as
to retard particles entering said electric ?eld from the
The second end 230 of the envelope 226 is provided 15 direction of said magnetic ?eld.
with a pair of spaced resonating units 232, 234 having
3. The system of claim 2 further characterized in that
their central portions 236, 238 extending into the envelope
said means for projecting said beam comprises an electric
larged.
226 forming respective apertures 240, 242 along the linear
path of the beam of electrons. The resonating units
232, 234 are of the usual type made of a conducting ma
terial and having annular cavity regions 244. The res
onating unit 232 which precedes the unit 234 along the
accelerating ?eld of predetermined strength, said system
further comprising means for varying the strength of said
20 retarding electric ?eld over a range of values extending
beam of electrons is connected to a terminal 246 for re
ceiving input signals which may be of radio frequency,
both above and below that of said accelerating electric
?eld.
4. A system for modulating the intensity of a beam of
electrically charged particles, said system comprising: an
while the resonating unit 234 is connected to a terminal 25 electrode for emitting said particles; means for forming
248 for delivering an output signal.
said particles into said beam and projecting said beam
In operation, the beam produced by the device 224 is
along a predetermined path; means for establishing a
modulated by the input signal delivered to the terminal
magnetic ?eld transversely to said path whereby said beam
136 of the plate member 134. This beam which has its
is de?ected into a different path; and means for re?ecting
amplitude modulated passes through the opening 240 of 30 back into said ?eld along a reciprocal of said dilferent
the resonating unit 232 which accelerates and decelerates
path a controllable fraction of the particles in said beam
the electrons in accordance with the input signal delivered
while absorbing the remainder, said last-named means
to its terminal 246. When the beam of electrons pass
comprising an electrode disposed in said different path and
through the opening 242 of the resonating unit 234 they
means for varying the potential of said electrode over a
induce an appropriate signal therein which is delivered 35 range of values extending both above and below the po
to terminal 248. This output signal, thus, is modulated
by the input signals to the terminals 136 and 246. The
electrons which emerge from the opening 242 impinge
tential of said emitting electrode.
5. The system of claim 4 further comprising an elec
trode for shielding said electrode of variable potential
upon and are removed by the collector plate 231 which
from other electrodes affecting said beam.
is returned to a positive potential.
40
6. The system of claim 4 further comprising means for
The device 224 provides a beam of electrons which is
increasing the cross-section of said projected beam before
not defocused by the modulating input signals and has
traversal of said magnetic ?eld.
the further advantage of being driven by a small input
7. The system of claim 6 further comprising means for
signal voltage and requiring low power. The construc
tion also reduces the noise output which would be pro 45 reducing the cross-section of said re?ected beam after
traversal of said magnetic ?eld.
duced by partition noise caused by collisions of the elec
trons of the beam with electrodes in the beam path.
Although the above devices illustrate some of the forms
References Cited in the ?le of this patent
of the invention and some of its uses, the invention may
be utilized in other devices such as backward traveling 50
wave tube as well as various other forms of ampli?ers
and signal generating and combining means.
While only a few representative embodiments and
methods of practicing the invention disclosed herein, have
been outlined in detail, there will be obvious to those 55
skilled in the art, many modi?cations and variations ac
complishing the foregoing objects and realizing many or
all of the advantages, but which yet do not depart essen
tially from the spirit of the invention.
UNITED STATES PATENTS
2,159,534
2,205,071
2,332,876
2,416,302
2,416,303
2,452,075
2,460,402
2,651,000
Ruska _______________ __ May 23,
Skellett _____________ __ June 18,
Uhlmann ____________ .._ Oct. 26,
Goodall _____________ __ Feb. 25,
Parker ______________ __ Feb. 25,
Smith _______________ _- Oct. 26,
Sziklai _______________ __ Feb. 1,
Linder _______________ _._ Sept. 1,
1939
1940
1943
1947
1947
1948
1949
1953
UNITED STATES PATENT OFFICE
CERTIFICATE OF CORRECTION
Patent No. 3,023,342
February 27,
1962 '
Glenn W. Preston
It is hereby certified that error appears in the above numbered pat
ent requiring correction and that the said Letters Patent should read as
corrected below.
Column 1, lines 47 and 48, for "transductance" read
—— transconductance ——; column 8, line 75, after "of" insert
—— input ——; column 9' line 6, for "receive a plurality of
input signals "
read
—— nection with electric
computers
——,,
Signed and sealed this 2nd day of April 1963.
(SEAL)
Attest:
ESTON G. JOHNSON
DAVID L. LADD
Attesting ()fficer
Commissioner of Patents
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