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Патент USA US3040329

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June 19, 1962
Filed Dec. 9, 1958
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United States Patent O
Patented June 19., 1962
Constantino Lucanera, Blauvelt, N.Y., and Frank E.
Kolinsky, Wanaque, and Ernest J. Annechiarico, Ram
sey, NJ., assignors to International Telephone and
Telegraph Corporation, Nntley, NJ., a corporation of
thus changing the frequency response of the antenna sys
tem. These alterations in length have also caused the
percentage of modulation of the carrier frequency to
vary appreciably with increasing elevation angles so that
the percentage of modulation does not remain constant
as elevation angle increases. Obvíously, in many in
stances, such changes in the coupling resulting in fre
quency response changes and changes in percentage mod
ulation With elevation angle are undesirable, even though
10 it is desired to alter the overall percentage modulation.
In other instances, it may be desired to al-ter the fre
This ínvention relates to beacon antenna's and more
quency response of the antenna system vvithout changing
particularly to beacon antennas producing a rotating multi
the overall percentage modulation. Neither of these de
lobed pattern of radiation in which the rotating lobes serve
sired conditions can be achieved by altering the length
to modulate the carrier signal radiated in any given di
rection. The antenna system described in this ínvention 15 of the parasitic elements in antenna systems, such as
shown in the Pickles patent.
produces relatively constant percentage modulation of
Therefore, it is a principal object of this ínvention
said carrier frequency up to high elevation angles.
to provide a directional antenna system having none
In the past, beacon antennas have been employed to
of the above-mentioned limitations.
radiate a carrier frequency in a rotating multilobed pat
tern thereby producing carrier modulations in any given 20 It is another object to provide a directional antenna
system in which the Shape of parasitic elements at ?Xed
direction from which Vehicles having receiving equipment
positions may be altered to change frequency response
on board may determine their relative bearings to said
and/or the ratio of the gain of the antenna in the direc
beacon. One such beacon is described in Patent No.
tion of its lobes to its gain in directions between lobes,
2,836,820, of S. Pickles et al., ?led January 4, 1955.
The beacon antenna described in the Pickles patent con 25 'without altering said ratio at increased elevation angles.
It is another object to provide an improved beacon
sists, brie?y, of a central vertically polarized radiator
antenna having a rotating multilobed pattern of radiation
coupled to a transmission line with parasitic elements
employing parasitic elements which may be altered in
spaced for rotation about the central radiator. The ro
size and shape to increase or decrease antenna directivity
tation of these parasitic elements about the central radia
tor produces the rotating lobes in the pattern of radiation 30 without altering frequency respo-nse or percentage modu
lation of the carrier frequency at increased elevation an
from the beacon, and these parasitic elements are essen
Filed Dec. 9, 1958, Ser. No. 779,151
1 Claim. (Cl. 343-761)
tially vertically arranged straight conducting members.
The use of parasitic elements to alter the directivity
It is another object to provide such a beacon antenna
of an antenna, as in the Pickles patent, -is a well-known
having low overall height including parasitic elements dis
cept some of the energy radiated from a driven antenna
element and then re-radiate it. The re-radiated energy
combines with the energy radiated by the driven antenna
radiator in which said parasitic elements may be con
technique. In operation the parasitic element will inter 35 posed for rotation about a central vertically polarized
siderably longer than said overall height.
It is a feature of this ínvention to provide an antenna
having a directional radiation pattern comprising central
element in such a way to modify the directional pattern
of the driven element creating lobes in that directional 40 radiating elements and at least one loop parasitic ele
ment disposed to intercept radiation from said central
pattern. The degree of modi?cation depends upon the
relative positions of the driven and parasitic elements, the
magnitude of currents ?owing in them and the relative
element thereby creating the directional pattern.
It is another feature to provide a beacon antenna hav
phase of the currents. Parasitic elements increasing the
ing a rotating directional radiation pattern comprising
directors while parasitic elements that increase the gain
in the direction from the parasitic element to the driven
Vertical radiator, each lying substantially in a plane per
pendicular to radial lines from said Vertical radiator.
element are called re?ectors. It is also well known to
the art that a parasitic element located a ?xed distance
It is a feature of one embodiment of this ínvention
to provide an antenna system employing a Vertical ar
from a driven element which is energized by a given
frequency, can be caused to be a re?ector or a director
rangement of said loop parasitic elements for rotation
abou-t a multiple element Vertical radiator energized by
depending on its length.
a carrier frequency signal to create a fundamental lobe
gain of the driven antenna element in -the direction from 45 a vertically polarized central radiator, a plurality of loop
parasitic elements disposed at equal distance from said
the driven element to the parasitic element are termed
Consequently, lobes in the
in the pattern of carrier frequency radiation, the length
made more pronounced or less pronounced by altering 55 of each of said loops being ?xed to achieve a given per
centage modulation of said carrier frequency in any
the length of a parasitic element at a ?Xed distance from
given direction and the height of each of said loops being
the driven element.
radiation pattern from a driven antenna element can be
?xed to tune said system and maintain percent modula
tion Constant even at increased angles of elevation, and
adjusted by altering the length of the parasitic elements. 60 -to employ other parasitic radiators disposed at a greater
radial distance from said central radiator for rotation
However, such alterations in the length of these para
thereabout to create harmonic lobes in the pattern of
sitic elements also altered the coupling between the para
carrier frequency radiation energizing the system.
sitic element and the central driven antenna elements,
In the past, the lobes in the radiation pattern from an
tennas, such as described in the Pickles patent, have been
It is a feature of another embodiment of this inven
tion to provide an antenna system employing a V-shaped
parasitic element disposed for rotation about a vertically
polarized central radiator energized by a carrier-frequency
signal with a plurality of loop parasitic elements disposed
at a greater radial distance for rotation about said central
the rate of rotation and number of lobes in said pattern.
In this embodiment, these modulating frequencies are a
fundamental, resulting from rotations of the fundamental
lobe created by the loop parasitic elements and a har
monic, resulting from rotations of the harmionic lobes
created by the straight parasitic elements.
radiator, the length of each of said loops being ?xed to
In operation Spoiler plate 6 serves to re?ect radiation
achieve a given percentage modulation of said carrier fre
emanating from the upper part of the central radiator
quency in any given direction and the height of each of
which is directed by conductive loop 3 and when re?ected,
said loops being ?xed to tune said system and maintain 10 this radiation adds to the gain of the system at high eleva
percent modulation constant even at increased angles of
tion angles. Loop elements 3, 4 and 5 are elliptical, as
elevation, said V-type element producing a fundamental in
shown in the ?gure. However, these elements may be
the radiation pattern and said lobe elements producing
loops of any shape and may be open loops rather than
harmonic lobes, the height of the system being preferably
closed loops. If these elements are open loops, the open
15 ends are preferably separated only a few tenths of a wave
less than the length of one of the loop elem-ents.
The foregoing and other objects and features of this in
length. Some of the advantages of employing these loops
vention and the manner of attaining them Will become
are that the height of a loop may be ?xed while its length
more apparent and the invention itself will be best under
may be altered considerably. Consequently, by ?xing the
stood by reference to the following description of an em
height of the loops, the frequency response of the antenna
bodiment of the invention taken in conjunction with the 20 system remains ?xed and by altering the length of the
accompanying drawings, comprising FIGS. l, 2 and 3,
loops, the percentage of fundamental modulation of the
carrier frequency radiated by element 1 may be altered
and this alteration in fundamental carrier frequency mod
producing a rotating multilobed pattern having a funda
ulation may remain constant up to high elevation angles.
25 The distance from center line 13, upon which are located
mental and ninth harmonic lobes;
FIG. 2 is a pictorial cutaway view of a simple beacon
a number of straight parasitic elements to counterpoise
antenna having minimum overall height for producing a
surface 14, is preferably ?ve-fourths of a wavelength
rotating pattern of radiation having a fundamental lobe
while the diameter of spoiler plate 6 is preferably three
and harmonic lobes; and
halves of a wavelength when the diameter of cylinder 7 is
FIG. 3 is a detailed cutaway view showing the central 30 three wavelengths.
radiator and disposition of lobe parasitic elements of the
Turning next to FIG. 2 there is shown another embodi
antenna system shown in FIG. 1.
ment of this invention depicting a beacon antenna having
Turning ?rst to FIG. 1 there is shown the top of a cen
an overall height of approximately one wavelength, and
tral vertically polarized radiator 1. This central radiator
consisting of a vertically polarized radiator 21 coupled to
is shown in more metail in FIG. 3 and is preferably con 35 the central element 22 of coaxial transmission line 23.
structed and energized, as described in Patent No. 2,762,
The outer element 24 of coaxial line 23 is coupled by
045 of G. Stavis et al., ?led October 8, 1952. Concentric
some suitable means to conductive plate 25, which acts as
with this central radiator is a dielectric cylinder 2 for sup
a counterpoise surface for the system. Disposed concen
porting conductive loops 3 and 4 and 5, as well as conduc
tric with element 21 and supported by plate 25 are di
tive spoiler plate 6. These conductive loops serve as
electric cylinders 26 and 27. Cylinder 26 serves to sup
parasitic elements altering the directivity of radiation from
port V-shaped parasitic element 28 while cylinder 27 sup
central radiator 1. A second dielectric cylinder 7 also
ports a number of loop parasitic elements., such as ele
FIG. l is a pictorial cutaway view of a beacon antenna
concentric With central radiator 1 serves to support other
ment 29. Motor 30 drives plate 25 in rotation about cen
parasitic elements such as straight elements 8, 9 and 10.
tral radiator 21 through suitable mechanical coupling
As shown in the ?gure, straight elements 8, 9 and 10 are 45 consisting of, for example, gear box 31 and gears 32 cou
each orientated in cylinder 7 on different center lines
pled to an extension of plate 25.
circumferentíal with cylinder 7. These different center
A beacon antenna, such as shown in FIG. 2, has a pre
lines are lines 11, 12 and 13, respectively. Numerous
ferred overall height of one wavelength or less with a
other straight parasitic elements, such as for example, 50 diameter of approximately three wavelengths. Such an
antenna is most useful where space and weight of antenna
eight other elements are also located on these center lines.
structure must be minimized, such as in certain Vehicles
The preferred orientation of the center lines 11, 12 and
like a submarine or aircraft. Here again, the loop para
13 upon which the straight parasitic elements are located,
sitic elements such as element 29 may have a ?xed mini
with regard to the location of loop parasitic elements 3, 4
and 5, respectively, are as follows: Center line 11 forms 55 mum height and their length may be varied over a wide
range to increase or decrease percentage modulation in
a plane which bisects conductive loop 3 while line 12
carrier frequency without appreciably eifecting the tuning
forms a plane which bisects conductive loop 4 and line
of the antenna system and without appreciably eifecting
13 forms a plane which bisects conductive loop 5. The
changes in percentage modulation with elevation angle.
distance between centers of conductive lobes 3 and 4 is
While there is described above specific embodiments of
preferably about one wavelength of the center frequency 60
this invention, it should be apparent that lobe parasitic ele
of the band over which the antenna system is operated and
ments having shapes other than round or oval may be em
the distance between centers of loops 4 and 5 is also one
ployed, as described, without deviating from the spirit and
scope of the invention and that numerous types of open
Dielectric cylinders 2 and 7 are supported by counter
poise surface 14 which may be coupled through suitable 65 loop parasitic elements having openings within the limita
tions mentioned above could be employed in the manner
described in place of those shown without deviating from
conducting carrier frequency signals. The inner conduc
means to the outer conductor 15 of transmission line 16
tor 17 of transmission line 16 is coupled to central radia
tor 1, as shown in FIG. 3.
Motor 18 serves to rotate sur
the spirit and scope of the invention as encompassed by
the following claim.
We claim:
face 14 about central radiator 1 and for this purpose gear 70
An antenna system having a rotating radiation pattern
box 19 and gears 20 couple the output of motor 18 to
with a fundamental and harmonic lobes, said fundamental
an extension of surface 14. Consequently, the multilobed
lobe being created by a ?rst group of parasitic elements
pattern of carrier frequency radiation created by the cen
and said harmonic lobes being created by a second group
tral radiator and the parasitic loops and straight members
is rotated. This rotation causes the carrier frequency to 75 of parasitic elements comprising a central vertically
polarized radiator having an axis and consisting of a plu
be modulated at modulating frequencies proportional to
about said central radiator, the length of said loop para
sitic elements determining the amount of fundamental
rality of biconical elements arranged in a Vertical manner
along said aXis, a plurality of Curved loop parasitic ele
modulation in said radiation pattern of said antenna, the
height of said loop in a direction parallel to said axis deter
mining the tuning response of said antenna for said funda
mental lobes.
ments to create said fundamental lobe disposed one above
another on a cylindrical surface concentric with said cen
tral radiator each said loop parasitic element being curved
about said axis with all portions of said parasitic element
being at the same radial distance from said axis Whereby
the radiation from all points of any one of said loop para
sitic elements is in phase and a plurality of other parasitic
elements disposed on another cylindrical surface concen 10
tric with said central radiator, said second group of ele
ments being arranged in sub-groups in different horizontal
planes, each plane bisecting a different one of said loop
parasitic elements each of said planes being separated from
an adjacent plane by a distance of substantially one wave
length, said cylindrical surfaces being supported by ro
tatable means and drive means for rotating said surfaces
References Cited in the ?le of this patent
Bruce _______________ __ Aug. 15,
Breen et al ____________ __ Aug. 30,
Hatch et al ____________ __ June 24,
Foster _______________ __ Feb. 22,
Pickles et al ___________ __ May 27,
Stavis et al ____________ __ Dec. 23,
Lucanera et al _________ __ Nov` 10,
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