Document 6606283

Nov. 7, 1933.
w. F. CURTIS
1,933,970
FREQUENCY DIVIDER
Filed March 17, 1931
2
IN VEN TOR.
‘Wm/£62? g: (BM/‘4%,
A TTORNEY
Patented Nov. 7, 1933
. 1333970
UNITED STATES PrAreuT oFFicn
‘1,933,910 »
FREQUENCY mvnmn
Westley F. Curtis, Washington, D. C.~
Application March 17, 1931.- Serial No. 523,373 r
5 Claims. (01. .zso-f-ssl '
tems and more particularly to a circuit arrange
v1'"! is coupled to inductance ll'of resonance circuit
10 andisconnected through-circuit 18120 alcoh
ment for effecting a .division of frequency;
stant fr'equencyoscillator. An oscillator which is
My invention relates broadly to oscillator sys
One of the objects of my invention is to pro piezo electric crystal controlled ‘may be em
5 vide a circuit arrangement for a frequency divider through
ployed'for
inductance
delivering17 constant
to the resonance
frequency
circuit
energy
10.
by which a submultiple of a predetermined funda
The
resonance
circuit
10
is
tuned'by
condenser
mental frequency may be sustained at‘a constant
value.
pressed fundamental frequency.
12 and adjustable-tap42 oninductance all to cor
'
Another object of my inventionis to provide ‘a
.119 circuit arrangement for a‘ frequency divider
wherein a fundamental frequencymay be applied
to the input circuit of the divider and a sub
multiple frequency derived from ‘the output cir
cuit of the frequency divider and maintained at
constant frequency in synchronism with .the im—
'
respond .with {the frequency of the piezoelectric
crystal controlled oscillator circuit. The circuit ‘35
constituted by inductance 4 ‘and variable con
denser 1_4 is adjustedto times‘lthe frequency
.of the circuit-1.0. 'When the vhigh frequency is
impressed upon the circuit 10, it operates in 7
. synchronism with the impressed’frequency ‘and
Other and further objects of my invention re
side in the circuitarrangement for afrequency di
vider as set forth more fully in the speci?cation
20 hereinafter following by reference to ‘the accom
panying drawing, in which:
Figure 1 diagramatically illustrates a circuit
for the purpose of describing the theory of my in
vent-ion; Fig. 2 shows a circuit arrangement em
the circuit vv4~—1!l is thus controlledby the im
division circuitof my invention; and.Fig..3 shows
an arrangementof an inductivelycoupled circuit
.30 by which connection may be made .to the low .fre
quency oscillator of the frequencydivision circuit.
Referring to the drawing in detail, reference
character 1 designates an electron tube having
cathode la, grid lb, and plate .lc with the input
' and output circuits coupled through the induct
ance 4. The grid electrode lb is connected
through through condenser .2 to ‘the terminal ‘3
of inductance 4. The plate electrode 10 ,is con
high resistance leak path .23 .is connected across
pressed frequency at a ‘value of
pressed frequency.
.
-
times ithe im
'
3.5
Fig. .2 shows the application of the frequency
‘
divider principle which has been illustrated in
Fig. 1. YA high frequency ampli?erZO constituted
by anelectron tube having a cathodeZOcca grid
' bodying my invention and employing a high fre 20?) anda plate 200 is provided with aninputcir .80
quency ampli?er directly coupled with the low cuit 21 and an ,outputcircuit 22, the input circuit
frequency oscillator constituting ‘the frequency 21 being connected to theinput terminals .24. A
" 40
the grid electrode .20b.and ‘the cathode 20a. ' .The
output circuit 22 of the high frequency ampli?er 7.
20 includes aresonance-circuit25. Aiconnection
extends from resonance :circuit :25 ‘through con
denser 3'7 to one end of raniinductanceBO forming
part of the low {frequency oscillator'circuit which
includes‘.electrontube26. The inductance ‘30 has .90
ajsliding tap-connection 32 thereon ,whichis-con
.nected .to the opposite endof the resonance cir
cuit 25. The .low frequency oscillator .26includes
nected throughtconductor v41 to the adjustable tap an inputcircuit 27 vwhich is bridged tbiyia high
resistance leak path 34 andconnected through
ductance 1i,connectsthrough‘condenser '7 with the condenser 35 with one end of the inductance 30‘
circuit of the cathode in. Battery V8 is employed on one side and connected to the cathode ‘circuit
,5 on inductance 4. Atap dadiustablecalong in
for heating the cathode ,la. .Highresistance leak on the other side. Battery 36 is providedjfor
path 191$ connectedvacross the grid ‘lb and cir heating‘ the cathode circuit of tubes .20 and 26. 100
cuit of the cathode .1a. .A resonance circuit 10 .is The plate circuitenergyfor both tubes 20 and,26
shown constitutediby,inductance 1'1 and variable .is obtained from battery 29 by meansof the con
condenser 12 which connects to the inductance'll nection .to the mid-point v31 of inductance ‘30
through theadjustable tap 42. A sliding connec thus ._completing the high potential circuit
tion 15 on inductance 11‘ is connected through through the right hand portion of inductance ' 30
sliding contact 16 to ‘the inductance 4. .A reson to the .plate circuit ,of tube 26 and completing 105
ance-circuit is providedhy the connection of vari— .the .high potentialcircuit for tube .20 through
able condenser‘ 1% across a portion of inductance that portion of ‘inductance ‘30 included'between
1i by means of the adjustable tap 16. The high center tap 31 and slidable'tap' 32. The output
potential for the plate circuit of the oscillator of the frequency division circuit is shown at 33.
In lieu of the conductive connection to the low J10
system is obtained from battery 9. A coupling coil
2
1,933,970
frequency oscillator from the high frequency am
pli?er 20 I may apply the high frequency energy
prior to the frequency division operation to the
circuit as illustrated in Fig. 3, where the high fre
pressing energy upon said resonant circuit at a
frequency which is a multiple of the fundamen
tal frequency of said oscillator and means for
tuning said series circuit to a sub-multiple of
quency energy is applied across terminals 40 to said impressed frequency for deriving from said
the inductance 39 which is inductively coupled to oscillator a sub-multiple of the impressed fre
the inductance constituting part of the reso quency.
nance circuit 25.
I
>
2. A frequency divider comprising an electron
As illustrated in the circuit in Fig. l, a funda tube oscillator, input and output circuits for said
10 mental frequency 1‘, equal approximately to some
oscillator, an inductance connected in common to
multiple of the frequency of the oscillator circuit, said input and output circuits for sustaining os
is applied to the terminals 18. In Figs. 2 ‘and 3, cillations at a fundamental frequency, a circuit
the resonance circuit 25 is tuned to the funda connected in series between separated points on
mental frequency applied at the input terminals said inductance for impressing energy on said
15 24. The circuit of the low frequency oscillator inductance, at a frequency which is a multiple of
including inductance 30 and condenser 37 is the fundamental frequency of said oscillator and
tuned to a sub-multiple of the fundamental fre a tuning element connected with said output cir
quency whereby the fundamental frequency con cuit for tuning said output circuit to a sub-mul
trols the sub-multiple frequency. The energy de tiple frequency of the fundamental frequency for
20 livered at the output terminals 38 is sustained at deriving from said oscillator a sub-multiple of
a sub-multiple frequency at an extremely con
stant value. The tuning range of the inductance
30 and condenser 37 is made su?iciently broad to
include a number of sub-multiple frequencies of
25 a fundamental frequency which may be impressed
‘on the low-frequency oscillator 26 from resonance
circuit 25.
The operation of the circuit of my invention
has been found to be markedly independent of
80
85
90
95
the impressed frequency.
3. A frequency divider comprising an electron
tube oscillator, input and output circuits for said
oscillator, an inductance connected in common
to said input and'output circuits, an auxiliary 100
circuit comprising a resonant circuit and-a vari
able reactance connected in series said auxiliary
circuit being connected in shunt with a portion
of said inductance, said resonant circuit having
30 variable battery voltages. When ‘the frequency energy impressed thereon at a multiple of the 105
is controlled by an external source of high fre fundamental frequency of said oscillator, and said
quency, the filament voltage on both the ampli
?er and the oscillator may be changed by 50%
without changing the frequency, or the plate
35 voltage may be changed by 50%, or both simulta
neously may be changed 25% without changing
the operation of the frequency divider system.
The capacity of condenser 37 must be maintained
within 1% but the condenser 43 in resonant cir
40 cuit 25 may change 20% without appreciable
damage. The amplitude of the harmonic in cir
cuit 25 and hence the stability of control increases
with increasing coupling between the circuit
30-37 and the circuit 25. As the inductance 44
45 is common to the two circuits 30-37 and 25, in
creasing the ratio L2='C'2 and decreasing the ratio
variable reactance being tuned to a sub-multi
ple of the'fundamental frequency for deriving a
sub-‘multiple of- an impressed frequency from.
said oscillator.
4. A frequency divider, comprising an elec
tron tube oscillator, input and output circuits for
110
said oscillator, an inductance connected in com
monvto said input and output circuits, an auxil- ,
iary circuit connected between separated points 115
on said inductance, said auxiliary circuit includ
ing a resonant circuit and a variable condenser in
series, means for impressing energy upon said
auxiliary circuit whose frequency is a multiple.
of the fundamental frequency of said oscillator, 120
said variable condenser being tuned to a sub-mul
‘L1=C1 as well as increasing the inductive cou
tiple of the impressed frequency and a circuit
pling between inductance 30 and inductance 44 connected with said output circuit for deriving
increases the stability, where:
a sub-multiple of the impressed frequency from
50,
125
said oscillator.
‘
L1=inductance ofcoil ~30.
_5. A frequency division system comprising an
Cizcapacity of condenser 37.
electron tube oscillator having input and output
Lz=inductance of coil 44.
circuits, an inductance common to said circuits,
Cz=capacity of condenser 43.
an ampli?er circuit having a tuned output sys-,
While I have described my invention in certain tem, a source of potential for said oscillator con 130
preferred embodiments, I desire that it be un— nected with the midpoint of said inductance, a
derstood that modi?cations may be made and connection extending from one sideof said tuned
that no limitations upon my invention are in output system of said amplifier circuit to a tap
tended‘ other than are imposed by the scope of on said inductance for supplying operating ‘po
60 the appended claims.
, tential to the output circuit of said ampli?er, a 135
What I claim as new and desire to secure by‘ connection between the other side of the tuned
Letters Patent of the United States is as fol
output system of said ampli?er circuit and'one
lows:
,
end of said inductance, and a tuning device in said
1. A frequency divider comprising an electron last mentioned connection, said tuning device
tube oscillator including input and‘output cir
being adjustable to a frequency which is a' sub
140
cuits,‘ an inductance connected in common to the multiple of the fundamental frequency of said os
‘ input and output circuits of said oscillator, a se
cillator circuit for controlling the generation of a
ries circuit external to said inductance and ex sub-multiple ferquency of the fundamental fre
tending between one end thereof and ‘an adjust
able tap along said inductance, said series cir
cuit including 'a resonant circuit, means for im
75
quency having constant characteristics.
‘ 145
WESTLEY F. CURTIS.
150