SIGNAL JAMMING DEVICE COMPRISING A SINGLE NOISE GENERATOR

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP81-00120R000100050063-3
• Release Decision: RIFPUB
• Original Classification: K
• Document Page Count: 3
• Document Creation Date: December 20, 2016
• Document Release Date: January 3, 2000
• Sequence Number: 63
• Publication Date: October 14, 1969
• Content Type: CONT

Approved For Release 2007/09/21: CIA-RDP81-0012OR000100050063-3
Oct. 14, 1969
3,473,126
SIGNAL JAMMING DEVICE COMPRISING A SINGLE NOISE GENERATOR
Filed June 7, 1965
2\
DELAY
MA G. T
AMP 6-5
8'
FIG:2
INVENTOR:
PIERRE R. GUE,N/R1RD
ATTORNEY
Approved For Release 2007/09/21: CIA-RDP81-0012OR000100050063-3
 Approved For Release 2007/09/21: CIA-RDP81-0012OR000100050063-3
United StatePatent Office
- 3,473,126
Patented Oct. 14, 1969
1 2
witted through the two aerials is destroyed by the delay
3,473,126 circuit.
SIGNAL JAMMING DEVICE COMPRISING A The invention will be more fully understood from the
SINGLE NOISE GENERATOR following description taken in connection with the ac-
Pierre R. Guenard, Paris, France, assignor to CSF-Com-
pagnie Generale de Telegraphic Sans Fil, a corporation 5 companying drawing, wherein:
of France FIGURE 1 represents diagrammatically a jamming
Filed June 7, 1965, Ser. No. 461,859 device in accordance with the present invention; and
Claims priority, application France, June 12, 1964, FIGURE 2 represents diagrammatically an improved
978,076 embodiment of a jamming device in accordance with the
U.S. Cl. 325-432 Int. Cl. 1104k 3/00 10 present invention that permits obtaining high-power noise
6 Claims signals for highly efficient signal jamming in accordance
---~ - with the principle of the invention.
ABSTRACT OF THE DISCLOSURE Referring now to the two figures of the drawing where-
in the like reference numerals are used throughout the
This invention relates to signal jamming devices ann 15 two views to designate like parts and more particularly
comprises a single noise generator connected through to FIGURE: 1, reference numeral 1 designates a single
separate paths to two aerials having mutually perpen- source of noise, whose output is split into two channels
dicular directions of polarization and delay means in 2 and 3. In accordance with the present invention, a
one of said paths to provide a non-coherent relationship microwave delay line 4 is inserted into one of the chan-
between the signals transmitted by the two aerials. Spe- 20 nels, for example, in channel 3. The delay time of the
cial amplifier means may also be provided in each of line may be of the order of the inverse of the band width
the paths to increase the signal strength while still main- covered by the signal receiver that has to be jammed. The
taming the random amplitude variation in each of the output of channel 2, on the one hand, and that of the
signal paths. The signals in each of the paths may be delay line 4, on the other, are connected respectively to
provided to a hybrid junction device to energize the two 25 two aerials 5 and 6 having mutually perpendicular polar-
aerials with signals representing the sum and difference izations.
of the signals in each of the separate paths. In the arrangement of FIGURE 1, the noise signals are
transmitted with a very low power, corresponding to that
of noise sources known in the art, It may therefore be
It is known that when a signal is disturbed or "jammed" 30 necessary to amplify these signals. Now, if high efficiency
by means of a single source of noise, it is easy at the re- amplification is desired such as obtainable with M-type
ception point of the signal to eliminate the jamming in amplifiers, these amplifiers cut down or clip the peaks
spite of the random character thereof. Indeed the noise of the amplified signal curve; consequently, the spectrum
is generally transmitted through an aerial or antenna that components of the output curve still have random fre-
radiates with a certain polarization; therefore, if the re- 35 quencies, but their amplitude has no longer random
ceiving aerial or antenna is arranged to have ~a polariza- values, since the amplitude of the different components
tion perpendicular to that of the transmitter, the jam- have been equalized by the amplitude limiting action of
ming of the signal is eliminated. the amplifiers. Thus, a portion of the random character
Things are nearly the same when the noise signal is of the noise signal is suppressed by the amplification, and
conveyed or fed over a double path and is transmitted 40 therefore these noise signals may be easier to overcome in
by means of two areals or antennae having mutually per- the receiver.
pendicular polarizations. The signals from the two aerials The arrangement shown by the schematic diagram of
then are coherent with one another and it is therefore FIGURE 2 has as its object the elimination of the fore-
possible at the reception point first to find out the way mentioned inconvenience,
of eliminating the jamming that has one polarization and 45 This arrangement comprises again the source 1, the
thence to deduce therefrom means for eliminating the channels 2 and 3, and the delay line 4. Each channel 2, 3,
jamming signal having the other perpendicular polariza provides an output signal for a high efficiency amplifier
tion, thus eliminating substantially the entire jamming. operating under saturation conditions; that is, under con-
Such a system of jamming is consequently ineffective ditions of peak limiting or clipping. The amplifiers, des-
and it may be rendered effective only by destroying the 50 ignated in FIGURE 2 by reference numerals 7 and 8,
coherence between the two noise signals. This can be are combined in a hybrid junction device 9, such as a
achieved when using two distinct, completely independent magic T-type device, which comprises two input branches
noise generators, but then the cost of installation is sig- for the signals, one output branch for the sum of the two
nificantly increased, signals and one branch for the difference of the same.
The present invention has as its object a signal jamming 55 The output signals, i.e., the sum and difference of the
device that comprises a single source of noise, but pro- input signals, respectively, are fed to the aerials S and 6
vides the same operational advantages as the prior art which have mutually crossed polarizations, as in FIG-
devices that comprise two distinct noise generators. URE 1.
Accordingly, it is an object of the present invention to The operation of this device is based upon the fact that
provide a highly efficient signal-jamming device that may 60 while amplifiers 7 and 8 provide signals in which only
be realized at a relatively low cost, the frequencies are random, there exists no correlation
In accordance with the present invention, there is between the frequency variations of these two signals
provided a signal jamming device comprising a single owing to the action of delay line 4. The combinations of
source of noise, means for conveying the noise signal the sum and difference of such signals provide each ;a
through two channels, a wave delay circuit inserted in 65 signal in which both the amplitude and the frequency
one of said channels for delaying the signal thereof, and are random. The aerials are consequently fed, like in
two aerials connected to the output of the two channels, FIGURE 1, by signals having no correlation therebe-
respectively, said two aerials having mutually perpen- tween, capable of jamming a desired signal, the power
dicular polarizations. of these jamming signals being relatively high owing to
The efficiency of this arrangement is due to the fact that 70 the amplifiers 7 and
8.
the coherence or correlation between the siennlc t,-,- wt,;I~ r H.,..o ,.,,,,..... ~___..?,
o embodi-
Approved For Release 2007/09/21: CIA-RDP81-0012OR000100050063-3
 Approved For Release 2007/09/21 : CIA-RDP81-0012OR000100050063-3
nzcnts in accordance with the present invention, it is
understood that the same is not limited thereto but is
susceptible of numerous changes and modifications as
known to a person skilled in the art; and I, therefore, do
not wish to be limited to these details but intend to cover
all such changes and modifications as are encompassed
by the scope of the appended claims.
I claim:
1.. A signal jamming device, comprising a single source
of noise modulated carrier signal, two separate radiating
means for radiating signals with different polarizations,
first connecting means connecting said single source with
one of said radiating means, second connecting means
connecting said single source with the other of said
radiating means, and wave retarding means in at least
one of said connecting means for delaying the arrival of
the noise modulated carrier signal from said single
source at the respective radiating means with respect to
the arrival of the noise modulated carrier signal at the
other radiating means.
2. Signal jamming apparatus, in combination, com-
prising:
a generating source for generating a noise modulated
carrier signal,
a first transmitter aerial polarized in a first direction,
,a second transmitter aerial polarized in a second direc-
tion perpendicular to said first direction,
said first transmitter aerial being connected to said
generating source;
signal delay means connecting said second transmitter
aerial to said generating source for delaying said
noise modulated carrier signal with respect to the
noise modulated signal at said first transmitter aerial,
and said first transmitter aerial and said second trans-
mitter aerial transmitting a non-coherent jamming
signal.
3. The signal jamming apparatus according to claim 2
wherein the delay time of -said signal delr me
ans
y
is
substantially the inverse of the hand width of the receiving
.
means to be jammed.
40 RALPH D. BLAKESLEE, Primary Examiner
4. The signal jamming apparatus according to claim 2 T T
%owl 8)473J26
4
ing said first and said. second transmitter aerials with said
generating source and the output of said signal delay line
means for producing two output signals, one of said out-
put signals being the sum of said noise modulated carrier
signal and the delayed noise modulated carrier signal,
and the other signal being the difference of said noise
modulated carrier signal and the delayed noise modulated
carrier signal.
5. The signal jamming apparatus according to claim 4
further including first and second amplifier means, said
first amplifier means interconnecting said generating
source and said hybrid junction means, said second am-
plifier means interconnecting said hybrid junction means
and said signal, delay means, said first and second am-
plifier means maintaining the random variation in the
amplitude of said noise modulated carrier signal.
6. The signal jamming apparatus according to claim S
wherein said hybrid junction means comprises a magic
T-type device having first and second input branches and
first and second output branches, said first input branch
being connected to said generating source, said second
input branch being connected to the output of said delay
line means, said first output branch being connected to
said first transmitter aerial, and said second output branch
being connected to said second transmitter aerial.
References Cited
UNITED STATES PATENTS
1,841,654
1/1932
Korsehemewsky 325--154
1,853,021
2
4/1932
Alexanderson _ 325-154
,401,575
2
6/1946
MacAdam. _____-_ __ 325-157
,792,493
5/1957
Duckett et al. 325-33
2,814,777
11/1957
Peters et al. --------- 325--132
-
-
-
3,014,985
12/1961
R.aisbeck .-_-_-___
_
_
___ 179--1
3,111,668
11/1963
Kuecken .-__--_ _____ 325-154
FOREIGN PATENTS
780,739
5/1935 France.
Approved For Release 2007/09/21: CIA-RDP81-0012OR000100050063-3