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Патент USA US2411205

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Nay. 19,1946.
‘
N, H, GREEN VETAL
2,411,205
ELECTRON DISCHARGE DEVICE
Filed July 18. L942. [ ' v
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Nov. 19,- 1946.
2,411,205
N. H. GREEN ETAL
ELECTRON DISCHARGE DEVICE
Filed July 18- 1942
2 Sheets-Sheet 2
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41
INV NTORS
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TTORNEY
Patented Nov. 19, 1946
2,411,205 '
UNITED STATES I” PATENT OFFICE
2,411,205
ELECTRON DISCHARGE DEVICE
Norval H. Green, Wood-Ridge, and William B.
Rupp, East Orange, N. J., assignors to Radio
Corporation of America, a corporation of Dela
ware
Application July 18, 1942, Serial No. 451,444
8 Claims. (01. 250-275)
Our invention relates to electron discharge de
vices, particularly suitable for use at ultra high
frequencies and utilizing a beam of electrons
periodically de?ected.
'
In one device of this kind a beam of electrons
2
described for obtaining optimum de?ection. It
has been found, however, that under certain con
ditions of operation, the expected de?ection is
not always obtained.
,
It is thus an object of our invention‘to provide
is directed through a focusing and de?ecting elec
an electron discharge device of the beam de?ec
trode system to a collector. The focusing and
tion type, which can be easily constructed and
de?ecting electrode system comprises a tubular
assembled, and in which di?iculty of alignment
member having a plurality of successively spaced
of electrode elements is substantially reduced.
apertured partitions with the apertures in align 10 Another object of our invention is to provide
ment. the apertures being elongated and of very
an electron discharge device of the type described
small width. ‘The de?ecting electrodes are posi
which will avoid the di?iculties pointed out in
tioned between the apertured elements.
connection with forming apertured elements.
Serious problems present themselves in the
A still further object of our invention is to pro
manufacture and assembly of such devices. One 15 vide an electron discharge device which is par
of the difficulties encountered is that of aligning
ticularly suitable for use at ultra high frequen
the apertures with the electron beam from the
cies and in which the deleterious effects of transit '
cathode assembly. Further di?iculties are ex
time may be substantially reduced and the trans
perienced in attempting to punch the transverse
conductance increased.
’
elements or partitions out of thin sheet metal 20 The novel features which we believe to be char-,
since the apertures are of such small dimensions
acteristic of our invention are set forth with par
that conventional punches will not withstand the " ' ticularity in the appended claims, but the inven
pressure necessary to provide the apertures.
tion itself will best be understood by reference
A still further dii?culty is experienced with this i
to the following description taken in connection I
type of tube in that at the very high frequencies, 25 with the accompanying drawings in which Fig
the transit time of the electrons becomes e?ective
ure 1 is a longitudinal section of an electron dis
to reduce the transconductance in a tube of this
charge device made according to our invention,
kind. The reason for this is that at the ultra ,
Figure 2 is a longitudinal section of the device
high frequencies the transit time of the electrons
shown in Figure 1 and rotated 90° with respect
between the de?ecting electrodes or plates is an 30 to the section taken in Figure 1 and its associated
appreciable part of the period of the applied de
, circuit, Figure 3 is an enlarged longitudinal sec
?ecting voltage. As a result an electron passing
between the platesamay not receive the maximum
tion of a cathode assembly and Figure 4 is a sec
tion taken along the line 4—4 of Figure 3, Fig
de?ection which a given voltage would normally
ure 5 is a view showing details of construction
cause. This may be explained in the following 35 and Figure 6 is a view showing the elements
manner.
shown in Figure 5 in the process of assembly,
Considering an electron entering the space be
Figures 7 and 8 are views of a jig used in‘ assem
tween the de?ecting plates at the moment of zero
bling the elements shown‘in Figures 5 and 6, and
potential difference between the plates, as the
Figure 9 shows details of construction of the ele
electron travels along between the plates, the 40 ments shown in Figures 5 and 6.
voltage differential increases to maximum and
An electron discharge device made in accord
then decreases to a zero value, and then again
ance with our invention ‘is shown in longitudinal
increases in the opposite direction. So long as
section in Figure 1. The device comprises an
the voltage on the' plates has the same sign the
evacuated envelope I 0 provided with the usual
45
electrons will continue to, be deflected in one di
base ll. Mounted at one end of the envelope is
rection but with the voltage reversed the electrons
are deflected in the opposite direction. The result
the cathode assembly comprising an elongated
cathode l3 and beam forming and shielding elec
trode l4, both of which are supported between
if an electron spends more than a half-period
between the plates is a de?ection less than that ' the pair of insulating spacer members I5 and I6,
which would occur under optimum conditions, 50 preferably of mica. Positioned at the other end
and the transconductance is reduced. In a co
of the envelope is collector I“! in the form of a
pending application of Kilgore, Serial No. 342,625,
?led June 27, 1940, and assigned to the same as
signee as the present invention, this matter of
_ loop and supported by means of glass bead assem
blies l8 and Hi from the intermediate electrode
assembly 20 for focusing and controlling the elec
transit time is discussed and certain relationships 55 tron. beam from the cathode assembly. The cath- '
2,411,205
3
a
ode assembly is supported from the electrode
4
2|’ in the ?rst apertured element 2|, so that the
beam is not misdirected through the aperture.
assembly 20 as best shown in Figures 3 and 4 to
be described below. Positioned within the tubular
member 20 are transverse apertured elements 2|,
‘As pointed out above it is di?icult to provide ’
the transverse elements with elongated apertures
of very small width due to the difficulty of pro
22 and 23 having elongated aligned apertures 2|’,
viding the proper tools for this operation. In
22' and 23’. An electron beam supplied from
cathode I3 is directed through the apertured
accordance with our invention we have over
come this di?iculty with the construction shown '
electrodes and between the de?ecting electrodes
24 and 24' to the apertured ‘element 23, the beam
in Figures 5 and 6 and by means of the method
being de?ected across 23' to vary the current to 10 described in connection with Figures 5 to 8, in
elusive.
collector | 1.
As shown in Figure 5, apertured transverse
element 23 comprises a disc-like member having
positioning apertures 39 and another aperture
circuit suitable for use with this type of device.
It will be noted that the de?ecting electrodes 24 15 39" over which the plate-like elements 36 and 31
are positioned and secured to provide the slot.
and 24' are of L-shape and supported from the
Longitudinally of the slot is positioned a rod-like
transverse element 22 by means of the bead con
The transverse section of the device shown in I
Figure 1 rotated 90° is shown in Figure ?)with one
element 38 which will be described in more de
struction 24". The transverse element 22 and
tail below, to provide a double aperture.
de?ecting elements 24 and 24' are maintained in
In Figures 7 and 8 is shown a jig arrangement
?xed position in a jig pending ?xing of these 20
for assisting in the assembly of the transverse,
elements with respect to each other with the
element 23. It comprises a base 40' having a pair
bead construction shown. The apertured ele
of pin-like elements 4| and an elongated element
ment 22 and de?ecting electrode elements 24 and
24' provide a lens action as described in the co
42 with a rectangular cross section which as ob
While for optimum results for de?ection sensi
tivity it has been found desirable to make the
length of the de?ecting plates in the direction
of travel of the electron beam equal to the dis
tance travelled by an electron during a ‘half 30
member 4|. In assembly, element 23 is posi
tioned over the pins 4| which extend through
apertures 39. The element 36 is then positioned
against the stop member 42 which ?ts into' the
recessed portion 36' of the element 36 and is
welded in position. The entire arrangement is
then lifted from the jig and rotated 180° and the
element 31 then positioned in place in the same
pending application of Kilgore mentioned above. 25 served is off center with respect to the pin-like
period, we have found that the capacity between
the plates, or the input capacity can be greatly
reduced, while decreasing the sensitivity to only
manner as element 36 was secured in place. The
a small, extent by making the length of the de
?ecting plates in the direction of travel of the 35 aperture is then ?xed with respect to the ele
ment 23'.
To properly center and ?x the rod-like element
38 to provide in e?‘ect a double aperture, the ele
electron beam equal substantially to a third of
the distance travelled by an electron during one '
period of the applied controlling voltage. Such a
reduction of input capacity is very desirable at
high frequencies.
In the arrangement shown the output is taken
between the collector I '| and the tubular member
20 by means of the output transformer 26. Con
denser 29 and resistors 21 and 28 permit the ap
plication of different D.-C. potentials on the col
lector and to the tubular member 20 and trans
verse element 23.
ments 36 and 31 are beveled on their underside
.11
When used as a mixer the
adjacent the aperture as shown at 36" and 31"
in Figure 9, and the wire 38 is of such diameter
that it ?ts with slidable contact between elements
36, 31 and the element 23. Only one end of this
rod-like element 38 is secured to the disc 23 to
thereby permit longitudinal expansion and con
traction of the element due to changes in tem
perature during operation. The element 38 is
thus positively ?xed in position with respect to
signal may be applied to the de?ecting electrodes
the aperture but at the same time is permitted
by means of the transmission line system 38 tuned
and shorted by means of the condenser shorting 50 to expand and contract without causing the ele
ment to bow or bend and thereby adversely aiIect
bar 3|, the signal being applied by transmission
the control voltage characteristic of the device.
line 32. The local oscillator voltage may be ap
Thus we provide an electron discharge device
plied by local oscillator 33 and transmission line
utilizing a periodically de?ected beam whichmay ,
34, the biasing *eoltage being supplied by means
be easily formed and assembled and in which
of ‘voltage source 35. The cathode shield and
. alignment of the electrode elements is assured.
beam forming electrode l4 may be biased by
In accordance with our invention transit time
means of the voltage source 36'. The electron
effects are reduced to a minimum so that the
disiharge device is of course useful in other cir
transconductance of the tube may be large.
cm s.
I
While we have indicated the preferred embodi
The details of the cathode assembly are best 60 ments of our invention of which we are now
shown in Figures 3 and 4. The cathode l3 and , aware and have also indicated only one speci?c
the cathode shield and beam forming electrode M
application for which our invention may be em
are positioned to extend through apertures pro
ployed, it will be apparent that our invention
is by no means limited to the exact forms illus-'
vided in the insulating spacer members l5 and
trated or the use indicated, but that many varia
I6, the element l4 being locked in position by
tions may be made in the particular structure
means of the tabs I4’. The insulating spacer
used and the purpose for which it-is employed
members are provided with ?nger-like elements
without departing from the scope of our inven
I5’ and I6’ which extend through the transverse
tion as set forth in the appended claims.
apertured element 2|, the assembly being main
What we claim as new is: >
tained in position by means of the rods I4" sealed
1; An electron discharge device having a cath
to the element 20 and directed through apertures
ode means for supplying a beam of electrons, a
' in the insulating elements. Due to the arrange
collector for receiving said electrons and means‘
ment disclosed the emitting surface |3"' of the
intermediate said cathode means and collector
cathode I3 is exactly aligned with the aperture 75 for focusing and controlling the beam of elec- ‘
2,411,205
5
6
trons, the intermediate means having a- plurality
of elements transverse to the path 0! said beam
and provided with apertures, said apertures being
aligned, said cathode means comprising an elec
trode assembly including a cathode and a pair of‘dl!
spaced supporting insulating members provided
with elements extending from said supporting in
sulating members and having oppositely disposed
aperturu receiving the ends of said cathode, one
of said transverse elements having apertures for
,
element adjacent the collector comprising a sheet
like element having an aperture centrallylthereoi',
a pair oi’plate-like elements positioned on and
secured to said sheet-like element with their ad
jacent edges in abutment, the adjacent edges of
said plate-like elements being provided with reg
istering recessed portions providing a, narrow slot
registering with the aperture in said sheet-like
element and of smaller dimensions than said last
aperture.
~
receiving the elements on said insulating mem
5. An electron discharge device having a cath
bers whereby said cathode and the other aper
ode means for supplying a beam of electrons, a
tures of the transverse elements are positively
collector for receiving'said electrons and means ,
aligned.
'
intermediate said cathode means and collector
2. An electron discharge device having a cath 15 for focusing and controlling the beam of elec
ode means for supplying a beam of electrons, a
trons, the intermediate means having a plurality
collector for receiving said electrons and means
of elements transverse to the path of said beam
intermediate said cathode means and collector
and provided with apertures, said apertures being
“for focusing and controlling the beam of elec
aligned, a pair of de?ecting electrodes intermedi
trons, the intermediate means having a plurality
ate the transverse elements, said cathode means
of elements transverse to the path of said beam
comprising an electrode assembly including a
and provided with apertures, said apertures being
cathode and a pair of spaced supporting insulat
aligned, said cathode means comprising an elec
, ing members provided with elements extending
trode assembly including a cathode and a pair of
from said supporting insulating members and
spaced supporting insulating members, said in
sulating members comprising ?at plate-like ele
ments having ?ngers extending from one edge
thereof and oppositely disposed, and having op
positely disposed apertures receiving the ends of
said cathode, one'of said transverse elements hav
ing apertures for receiving the ?ngers on said
insulating members whereby said cathode ‘and the
other apertures of. the transverse elements are
positively aligned.
having oppositely disposed apertures receiving
the ends of said cathode, one of said transverse
elements having apertures for receiving the ele
ments on said insulating members whereby said:
cathode and the other apertures oi the transverse
elements are positively aligned, the transverse
element adjacent the collector comprising a
sheet-like element having an aperture centrally
thereof, a pair of plate-like elements positioned
on and secured to said sheet-like element with
3. An electron discharge device having a cath 35 their adjacent edges in abutment, the adjacent
ode means for supplying a beam 01' electrons, a
edges of said plate-like elements being provided
collector for receiving said electrons and means
with registering recessed portions for providing a
intermediate said cathode means and cpllector for
. narrow slot registering with the aperture in said
focusing and controlling the beam of electrons,
sheet-like element and of smaller dimensions
the intermediate means having a plurality of ele
than said last aperture, and a rod-like element
ments transverse to the path of said beamand
extending longitudinally of said slot and centrally
' , provided with apertures, said apertures being
thereof.
aligned, said cathode means comprising an elec
6. An electron discharge device having a cath
trode assembly including a cathode and a pair 01!
ode means for supplying a,‘ beam ,of electrons, a
spaced supporting insulating members provided
collector for receiving said electrons and means
with elements extending from said insulating
intermediate said cathode means and collector
members and having oppositely disposed aper
for focusing and controlling the beam of elec
tures receiving the ends of said cathode, one of
trons, the intermediate means having a plurality
said transverse elements having apertures for
of elements transverse to the path of said beam
receiving the elements on said insulating members 50 and provided with apertures, said apertures being
whereby said cathode and the other apertures oi
aligned, said cathode means comprising an elec
the transverse elements are positively aligned,
trode assembly including a cathode and a pair
said intermediate means including a pair of de
of spaced supporting insulating members pro
?ecting electrodes adjacent one of the transverse
vided with insulating elements extending from
elements for de?ecting the beam of electrons
across the aperture of a transverse element more
closely adjacent to said collector.
4. An electron discharge device having a cath
ode means for supplying a beam of electrons, a
collector for receiving said electrons and means
intermediate said cathode means and collector for
focusing and controlling the beam of electrons,
the intermediate means having a plurality of ele
ments transverse to the path of said beam and
said insulating members and having oppositely
disposed apertures receiving the ends of said
cathode, one of said transverse elements having
apertures for receiving the elements on said in
sulating members whereby said cathode and the
other apertures of the transverse elements are
positively aligned, said intermediate means in-'
cluding a pair of de?ecting elements adjacent one
of said transverse elements for de?ecting the
beam of electrons across an aperture of a trans
provided with apertures, said apertures being 65 verse element more closely adjacent to said col
aligned, said cathode means comprising an elec
trode assembly including a ‘pair of spaced sup
porting insulating members provided with ele
ments extending from said insulating members
and having oppositely disposed apertures receiv
ing the ends of said cathode, one of said trans
verse elements having apertures for receiving the
lector, said de?ecting electrodes being L-shaped
and an insulating assembly supporting said L
shaped de?ecting electrodes from one of said
transverse elements.
7. An electron discharge device having a cath
ode means for supplying a beam of electrons, a
collector for receiving said electrons and means
intermediate said cathode means and collector
for focusing and controlling the beam of elec
elements on said insulating members whereby said
cathode and the other apertures of the transverse
elements are positively aligned, the transverse 76 trons, the intermediate means having a plurality
2,411,205
7
of elements transverse to the path of said beam
and provided with apertures, said apertures be
ing aligned, said cathode means comprising an
8
,
provided with ?ngers extending from said insu
lating members and having oppositely disposed
electrode assembly including a, cathode and
means aligning said cathode with the apertures
of the transverse elements, said intermediate
means including a pair of de?ecting electrodes
adjacent one of said transverse elements for de
?ecting the beam of electrons across the aper
ture in another transverse element nearer to 10
apertures receiving the ends of said cathode, one
of said transverse elements having apertures re
ceiving the ?ngers on said insulating members
whereby said cathode and the apertures in the
transverse elements are positively aligned, said
intermediate means including a pair of de?ecting
electrodes adjacent one of said ‘transverse ele
ments for de?ecting the beam of electrons across
said collector, said de?ecting electrodes having
the aperture in a transverse element nearer said
a dimension in the direction of travel of the elec
collector, said de?ecting electrodes having a di-'
trons substantially equal to the distance trav
mansion in the direction of travel of the electrons
elled by an electron during substantially one
substantially equal to the distance travelled by
third of a period of the voltage applied to said 15 an electron during one-third of a period 01' the
de?ecting electrodes.
applied controlling voltage on said de?ecting
8. An electron discharge device having a, cath
electrodes, the transverse element adjacent the
ode means for supplying a beam of electrons, a
collector comprising a sheet-like member having
collector for receiving said electrons and means
an aperture centrally disposed thereof, a pair ofv
intermediate said cathode means and collector 20 sheet-like elements positioned over said aperture
for focusing and controlling the beam of elec
and having adjacent edges contacting, said ad—
trons, the intermediate means having a plurality
oi.’ elements transverse to the path of said beam
and provided with apertures, said apertures be
ing aligned, said cathode means comprising an 25
electrode assembly including a cathode and a
pair of spaced supporting insulating members
jacent edges being provided with elongated slot
like recesses cooperating to provide an elongated
narrow slot registering with the aperture in said
sheet-like member.
NORVAL H. GREEN.
WILLIAM B. RUPP.
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