3,255,450
`J. L. BUTLER
`June 7, 1966
`MULTIPLE BEAMANTENNA SYSTEM EMPLOYING MULTIPLE
`DIRECTIONAL COUPLERS IN THE LEADIN
`4. Sheets-Sheet l
`
`Filed June l5, l960
`
`Fig.
`
`PROR ART
`
`
`
`-34
`
`Jesse L. Butler
`INVENTOR
`-6-4762-62-4-4-2-
`
`ATTORNEY
`
`

`

`3,255,450
`J. L. BUTLER
`June 7, 1966
`MULTIPLE BEAM ANTENNA SYSTEM EMPLOYING MULTIPLE
`DIRECTIONAL COUPLERS IN THE LEADIN
`4. Sheets-Sheet 2
`
`Filed June 15, 1960
`
`
`
`do3 Yb3
`IL
`4R
`
`(c3 yd3
`3L
`2R
`
`(e5 Yf 3
`2.
`3R
`Fig.3
`
`g3 Yh3
`4L
`R
`
`Jesse L. Butler
`INVENTOR
`
`-6%-222
`
`ATTORNEY
`
`

`

`3,255,450
`J. L. BUTLER
`June 7, 1966
`MULTIPLE BEAM ANTENNA SYSTEM EMPLOYING MULTIPLE
`DIRECTIONAL COUPLERS IN THE LEADIN
`Filed June 5, 1960
`4. Sheets-Sheet 3
`
`
`
`PREAMPLIFER
`CONTROL
`VOLTAGE
`
`Jesse L. Butler
`INVENTOR
`
`-64%2-62-6-4-
`
`s
`
`ATTORNEY
`
`

`

`3,255,450
`J. L. BUTLER
`June 7, 1966
`MULTIPLE BEAM ANTENNA SYSTEM EMPLOYING MULTIPLE
`DIRECTIONAL COUPLERS IN THE LEADIN 4. Sheets-Sheet 4.
`
`Filed June l5, 1960
`
`
`
`Jesse L. Butler
`-624%-2 INVENTOR
`ATTORNEY
`
`

`

`
`
`United States Patent Office
`
`3,255,450
`Patented June 7, 1966
`
`1.
`
`2
`gizing the inputs of four port power divider circuits which
`interconnect a plurality of antennas.
`3,255,450
`Other objects will hereinafter become obvious as a
`MULTIPLE BEAM ANTENNA SYSTEM EMPLOY
`NG MULTIPLE DIRECTIONAL COUPLERS IN
`description of the invention made wherein,
`FIGURE 1 shows a typical prior art multiple beam
`THE LEADEN
`Jesse L. Butler, Nashua, N.H., assignor to Sanders Asso
`antenna system for directional steering through signal
`ciates, Enc., Nashua, N.H., a corporation of Delaware
`phasing,
`Filed June 15, 1960, Ser. No. 36,219
`FIGURE 2 shows the multiple beam antenna system
`7. Claims. (Cl. 343-100)
`using the new components and order of connections fea
`tured in the present invention,
`This invention relates to multiple beam antenna sys
`FIGURE 3 shows a specific system for providing eight
`tems and more particularly to circuits and components
`directional beams from eight antennas, and
`comprising such systems for directional beam steering
`FIGURE 4 shows the relative orientation of the eight
`through selective phasing of signals from a plurality of
`beam patterns for the circuit of FIGURE 3,
`antennas.
`FIGURE 5 shows an arrangement of a four element
`Directional beam steering through predetermined phas
`array whereby transmitter beams may be switched in
`ing of signals from a plurality of antennas is well known
`and out by preamplifier control voltages,
`in the art. For example, an article entitled "Certain
`FIGURE 6 shows a transponder system whereby a
`Factors Affecting the Gain of Directive Antennas' by
`reply may be made only in the direction from which wave
`G. C. Southworth was published in the Proceeding of the
`energy is received, and
`Institute of Radio Engineers, volume 18, Number 9,
`FIGURE 7 shows a system for both vertical and hori
`September 1930, on pages 1502 to 1536, wherein phasing
`zontal signal beaming.
`of signals was discussed. In signal phasing, the energy
`Referring now to FIGURE 1, there is shown a typical
`from a single transmitter source was channelled into two
`eight antenna system wherein the eight antennas, a to h,
`or more antennas coupled by means of three port power
`are shown in a linear array wherein each antenna is
`dividers. These dividers have the characteristic that
`considered as a spherical source of waves radiating equal
`the in-phase components of signals fed to two ports will
`power in all directions. Adjacent antennas are coupled
`sum up and pass out the third port, whereas the out
`through three port power dividers, 11 to 14, to impedance
`of-phase components of the signals will continue beyond
`matching transformers, 15 to 18. Adjacent pairs of these
`the junction and not be useful. This, of course, results
`transformers are coupled through three port power divid
`in a loss of useful power in the power divider. In the
`ers, 19, 20, which in turn are coupled through transform
`same manner in receivers, a maximum range can be
`ers 21, 22 which in turn are connected to an energy
`achieved in a predetermined fixed direction through phase
`source or receiver 23 through another three port power
`shifting techniques, whereas if the system is adapted to
`divider 24. Through suitable wavelength spacing of the
`receive from more than the one beamed direction, this
`antennas from each other and phasing of the signal
`maximum range becomes foreshortened due to the at
`paths, the directional patterns can be varied as desired.
`tenuation in the three port power dividers. It has been
`The phase shifters 25 may preferably be an extra length
`found that with a new circuit arrangement for connect
`of transmission line to cause signals therethrough to lag
`ing the antennas, a four port power divider can be used.
`those signals going through the parallel paths.
`In the four port divider the sum of the power into the
`In FIGURE 2, instead of connecting adjacent antennas
`two input ports substantially equals the sum of the power
`into pairs and connecting adjacent pairs until all anten
`out of the other two ports regardless of the phase re
`nas are connected to the same source as in FIGURE 1,
`lationships of the signals. With additional connections
`the array is divided into right and left sections, separated
`to the fourth port another directional beam can be
`by a dashed line 26 for reference purposes. Correspond
`generated, utilizing the phase shifting and isolation char
`ing antennas in each section are coupled, for example,
`acteristics of the divider. Moreover, with the four port
`a and e, b and f, c and g, and d and h, through four
`power divider the impedance matching transformers may
`port power dividers 27, 28, 29, and 30. In other words,
`be eliminated. Thus, the multiple beam antenna system
`if there are x numbered antennas, those x/2 apart are con
`comprising this invention is more efficient, has additional
`nected through these dividers. Corresponding power
`directivity patterns, and requires fewer components than
`dividers in each section, are in turn coupled, as at 31
`those heretofore used.
`and 32, and recoupled at 33 to energy source 34. Suit
`It is therefore an object of the present invention to pro
`able phase shifters 25 are used as needed.
`vide for a four port power divider for use with a plu
`The four port power divider may be a wave guide top
`rality of antennas for directional beam steering through
`wall or sidewall coupler, a branch line coupler in wave
`phasing of feeder signals.
`guide, coax, or stripline, a stripline parallel-line coupler,
`It is another object to provide for an improved con
`or any of a number of coupler types which have the prop
`necting circuit in a multiple beam antenna system.
`erty of providing two outputs differing in phase by 90
`It is another object to provide for an improved multiple
`degrees, and conversely of coupling all the power to one
`beam antenna system wherein four port power dividers
`of two isolated ports when power is applied equally to
`are used in connecting circuits between a plurality of an
`two other ports with a 90 degree phase differential. This
`tennas and a plurality of associated receivers or trans
`60
`power divider may also be a branched directional double
`mitters.
`s
`stub coupler as discussed in the October 1956, issue of the
`Another object is the provision of a multiple beam an
`IRE Transactions on Microwave Theory and Techniques,
`tenna system wherein a pluraltiy of beams may be fed at .
`volume MII-4, Number 4, pages 246 to 252, in an article
`a time to the antennas or at the same time without sub
`65 by Reed and Wheeler entitled “A Method of Analysis
`stantial loss in beam range.
`of Symmetrical Four-Port Networks.' These dividers
`Another object is the provision of an improved switch
`differ from the three port dividers in that regardless of
`ing means for signal beam steering by selectively ener
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`the phase relationship of the signals fed into the inputs,
`the power leaving the outputs is substantially equal to
`the power into the inputs. Thus, it is possible to use
`the fourth ports of the dividers in FIGURE 2 for mak
`ing similar connections to another signal source 35 as
`shown by the dotted lines. In this manner the number
`of directional beams for the system may be doubled. As
`used herein, the term "power divider" is used in its or
`dinary sense, that is, to denote a device in which energy
`applied to an input port is divided between two other
`ports.
`The basic building block component in FIGURE 2
`of a four port power divider and a fixed phase shifter can
`be adapted readily to any array of two to the nth power
`elements where n is an integer, indicating the number of
`stages to be used. Thus, in FIGURE 3 where eight
`antennas are to be used and eight directional beams are
`desired this integer would be three, since 23=8. Here is
`shown schematically the feed structure for an eight
`element array with eight independent feed terminals and
`designed to produce eight patterns which will overlap
`at the three db points. If halfwave lengths spacing is
`used between the elements the patterns will cover a
`180-degree sector as shown in FIGURE 4. In the first
`stage the output terminal ports of the power dividers are
`connected to those antennas n/2, apart, where n is the
`number of antennas to be used.
`In FIGURE 3 the antennas a to h are connected to di
`viders 27 to 30 with each divider connected to correspond
`ing antennas in the left and right sections in the same
`smanner as in FIGURE2. Following the basic formula of
`connecting those elements together which are n/2 apart,
`where n is the number of elements, this constitutes the first
`stage with the input terminals of the dividers connected
`in the same manner to terminal points of the first stage
`a1 through hi. A second stage of power dividers 40,
`41, 42, and 43 likewise connect to these terminal points
`since there were four divider elements in the first stage
`with their input terminals connected at a1 through h1.
`40
`The power dividers of the second stage, 40 to 43, are con
`nected to these terminals in the same pattern of con
`necting those elements which are n/2 apart. Therefore,
`divider 40 will be connected to dividers 27 and 29 at
`points a1, c1, divider 41 will be connected to dividers 28.
`and 30 through terminals b1, d1, all being connected to
`the left input ports. Similarly, dividers 42 and 43 will
`be connected to the right hand input ports of dividers 27
`to 30. Divider 42 is thus connected to divider 27 atter
`minal e1 and to divider 29 at terminal g1. Also, divider
`43 is connected to divider 28 at terminal f1 and to di
`vider 30 at terminal h1. Phase shifters 36, 37, 38, and
`39 are connected to the outer output ports of dividers
`40-43 as shown. Terminals a2 to h2 form the input con
`nections for the power, dividers of the second stage.
`The third stage power dividers 48, 49, 50, and 51 are con
`nected to these terminals in a similar manner. However,
`in connecting the third stage dividers the dividers in the
`second stage must be considered as separate left and right
`sections, with dividers 40 and 41 being the left sections,
`since they connect to the left ports of the first stage di
`viders, and dividers 42 and 43 being considered the right
`section with their ports connected to the right ports of the
`dividers of the first section. Thus, with 40 and 41 con
`sidered as one section and following the formula for con
`necting those elements in?2 apart, divider 48 is connected
`to both left ports and divider 49 is connected to both right
`ports of dividers 40 and 41. In the same manner and
`considering dividers 42 and 43 to comprise one section,
`divider 50 is connected to the left ports and divider 51 is
`connected to the right ports of dividers 42 and 43. Con
`nections as and h3 form the input connections for energy
`sources to produce the various beam patterns identifie
`therewith and as shown in FIGURE 3.
`In FIGURE 4 there is shown an array for eight direc
`tional beams. If all energy sources were used at once
`
`3,255,450
`4.
`all eight directional beam patterns would result, as well as
`each beam resulting from the energization of the particular
`energy source.
`In FIGURE 5 for purposes of simplification four anten
`nas a, b, e and fare shown to illustrate the use of a
`single energy source used to provide four directional beams
`through the use of separate preamplifier control voltages.
`Here preamplifiers 58 to 61 are each connected to the in
`put ports of dividers 56 and 57, as shown. These ampli
`fiers are all coupled to oscillator 62. Each preamplifier
`has a control voltage which may be used as a switching
`means to provide for an output in the desired preampli
`fier. In this manner the desired beam pattern may be
`achieved, using a single source and controlling the pre
`amplifier outputs with a control voltage.
`FIGURE 6 shows an arrangement of circuitry which
`may be connected to the terminals as to h3 in FIGURE 3.
`Here a circuit is connected to each terminal. This con
`sists of a three port circulator 63 having one port 64 con
`-nected to the terminal and the other two, 65, 66 to an
`amplifier 67. This circulator has the characteristic that
`energy into one port will leave another port to the ex
`clusion of a third. Circulators of this type are discussed
`in an article "The Elements of Nonreciprocal Microwave
`Devices' by C. Lester Hogan in volume 44, October 1956,
`issue of Proceedings of the IRE, pages 1345 to 1368. As
`shown by the direction of the arrows, energy from port 64.
`passes out port 65 to amplifier 67. This amplifier may be
`connected in Such manner that the incoming signal may
`raise the amplifier signal level sufficiently to pass a new
`signal from signal source 68. This new signal from the
`amplifier output will enter port 66 and out port 64. This
`then becomes the signal source to terminal a3 to h3 in
`FIGURE 3. In this manner any incoming signal received
`by the antennas in FIGURE 3 will generate a return signal
`beamed in the same direction from which the original sig
`inal was received.
`In FIGURE 7 there is shown an arrangement for phas
`ing signals in a vertical as well as horizontal plane. Here
`four rows of four antennas each are used for purposes of
`illustration. For simplification, the complete phasing
`System for a four antenna array is shown in block form.
`Thus, the system in FIGURE 3, as applied to four anten
`nas, a to d, is shown in FIGURE 7 as “1,” with input
`terminals 69, 70, 71 and 72 for connection to similar sys
`tems. Four such systems '1' to '4' are shown in the
`center with systems "6" to “8” conveniently positioned
`vertically at the sides and without antennas. Instead of
`additional antennas, connecting terminals 101 to 116 are
`used. Terminals 101 to 104 of system “5” are connected
`to the input terminals 69,73, 77 and 81 on the left of sys
`tems “1” to "4.” Similarly, terminals 105 to 108 of
`system "6" are connected to the next terminals 70, 74,
`78 and 82 of systems “1” to “4.” The system “7” termi.
`nals 109 to 112 are connected to the right column of ter
`minals 72, 76, 80 and 84 while system “8” terminals 113
`to 116 are connected to terminals 71, 75,79, 83.
`A signal to any one of the input terminals of systems
`'1' to '4' will produce one of a possible four or sixteen
`directional beams in a horizontal plane, depending upon
`whether each system duplicates or varies from the beam
`projection of the others.
`However, by shifting the phase
`of signals fed into all four systems, the horizontal beam
`will become elevated in an amount indicative of the phase
`shift. For example, the output from system “5,” which
`depends upon which input 85, 86, 87 or 88 is used, will
`establish a phase relationship of signals to terminals 69,
`73, 77 and 81 of systems “1” to “4” thereby causing a pre
`determined elevation as well as a horizontal direction to
`the output beam. The other systems “6,” “7” and “8”
`likewise contribute a vertical signal phasing to produce an
`elevated signal, although the horizontal direction will dif
`fer since they feed different terminals of systems "1"
`Y to “A.”
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`

`5
`If systems “1” to “4” each produce identical beam pat
`terns and systems “5” to "8" also produce identical beam
`patterns, then the total system of FIGURE 7 will produce
`sixteen beams in four horizontal and four vertical pat
`terms. However, if each of the horizontal and vertical systems
`do not correspond with each other but are spaced in their
`beam projection, then the total system of FIGURE 7
`will project a beam pattern sixteen beams horizontally and
`sixteen beams vertically.
`It is to be understood that within the purview of this
`invention any number of antennas and associated dividers
`and phase shifters may be used. Although the antennas
`shown are in linear array, they may also be placed in
`other configurations as desired, provided suitable phase
`compensation is made.
`The amount of phase shifting of the signals depends
`upon the desired direction of the beam to be received or
`transmitted. This system is equally adaptable to reception
`as well as transmission of signals. Other variations and
`modifications are likewise to be construed as part of the
`invention, which is not limited to the embodiments which
`were above described for purposes of illustration only.
`What is claimed is:
`1. A transmission system comprising, in combination,
`first, second, third and fourth transmission line couplers,
`each of said couplers having first, second, third and
`fourth ports and being adapted to couple a signal from
`either of said first and second ports to said third and
`fourth ports with a fixed phase difference between the
`signals at said third and fourth ports and with equal
`amplitude at said third and fourth ports, first transmission
`means connected between said fourth port of said first
`coupler and said first port of said fourth coupler, second
`transmission means connected between said third port of
`Isaid second coupler and said second port of said third
`coupler, said first and second transmission means being
`of equivalent electrical length, third transmission means
`connected between said third port of said first coupler
`and said first port of said third coupler, fourth trans
`mission means connected between said fourth port of
`said second coupler and said second port of said fourth
`coupler, said third and fourth transmission means being
`of equivalent electrical length, said first and third trans
`mission means being of such different electrical lengths
`as to couple an input signal fed into one of said first
`and second ports of said first and second couplers equally
`to said third and fourth ports of said third and fourth
`couplers with a uniform phase difference between the
`signals coupled to said fourth ports of said fourth and
`third couplers, between the signals coupled to said third
`ports of said fourth and third couplers, and between
`the signals coupled to said fourth port of said third
`coupler and said third port of said fourth coupler.
`2. The combination defined in claim 1 in which said
`fixed phase difference is an odd integral multiple, includ
`...ing unity, of 90 degrees.
`.
`..
`3. The combination defined in claim 1 including an
`antenna connected to each of said third and fourth ports
`of said third and fourth couplers.
`4. The combination defined in claim 3 including a
`- source of radio frequency energy and means coupling
`said source to one of said first and second ports of said
`first and second couplers.
`65
`5. The combination defined in claim 1 further com
`prising
`(A) first, second, third and fourth spaced antennas,
`each of said antennas being connected to a differ
`ent one of said third and fourth ports of said third
`and fourth couplers,
`(B) first, second, third and fourth preamplifiers, each
`of said preamplifiers being connected to a different
`one of said first and second ports of said first and
`second couplers,
`
`3,255,450
`6
`(C) a single signal source having an output terminal
`connected to each of said preamplifiers, and
`(D) means for rendering selected ones of said pre
`amplifiers operative to thereby energize selected ones
`of said first and second ports of said first and Second
`couplers, thereby beaming selected signal patterns
`from said antennas.
`6. The combination defining claim 1 further compris
`ing
`(A) first, second, third and fourth antennas, each of
`said antennas being connected with a different one
`of said third and fourth ports of said third and fourth
`couplers,
`(B) first, second and third and fourth signal sources,
`(C) first, second, third and fourth transponder means,
`each transponder means being connected between one
`signal source and one of said first and second ports
`of said first and second couplers, said transponder
`means being actuated by a signal incoming thereto
`from said couplers and upon being actuated coupling
`the source connected with it to the port connected
`with it, so that a signal source is coupled with said
`antennas to transmit signals in the direction from
`which a signal is intercepted by said antennas.
`7. A multiple beam antenna system for selectively
`ibeaming signals in a direction selected along two orthogo
`nal axes said system comprising in combination
`(A) a plurality of antennas arrayed in rows and
`columns,
`(B) a plurality of intermediate terminals equal in
`number to the number of antennas and schematical
`ly arranged in rows and columns,
`(C) means interconnecting said intermediate terminals
`in each row thereof to the antennas in a different
`row thereof in such manner that the beam direction
`of signals radiated from said antennas is dependent
`upon which intermediate terminal is energized,
`(D) a plurality of input terminals arranged in groups
`with the number of groups being equal to the number
`of cqlumns of intermediate terminals and with the
`number of input terminals in each group thereof
`being equal to the number of intermediate terminals
`in a column thereof,
`(E) means interconnecting the input terminals in each
`group thereof with the intermediate terminals in a
`different column thereof,
`(F) each of said interconnecting means comprising at
`least first, second, third and fourth transmission line
`couplers, each of said couplers having first, second,
`third and fourth ports and being adapted to couple
`a signal from either of said first and second ports
`to said third and fourth ports with a fixed phase
`difference between the signals at said third and fourth
`ports and with equal amplitude at said third and
`fourth ports, first transmission means connected be
`tween said fourth port of said first coupler and said
`first port of said fourth coupler, second transmission
`means connected between said third port of said sec
`ond coupler and said second port of said third
`coupler, said first and second transmission means
`being of equivalent electrical length, third trans
`mission means connected between said third port of
`said first coupler and said first port of said third
`coupler, fourth transmission means connected be
`tween said fourth port of said second coupler and
`said second port of said fourth coupler, said third
`and fourth transmission means being of equivalent
`electrical length, said first and third transmission
`means being of such different electrical lengths as
`to couple an input signal fed into one of said first
`and second ports of said first and second couplers
`equally to said third and fourth ports of said third
`and fourth couplers with a uniform phase difference
`between the signals coupled to said third and fourth
`
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`3,255,450
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`8
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`OTHER REFERENCES
`ports of said third and fourth couplers and between
`said fourth port of said third coupler and said third
`Shelton, Perrino, Davis; Scanning Techniques for Large
`port of said fourth coupler
`Flat Communication Antenna Arrays; AFCRC-TN-60
`5 158; Astia AD No. 235571, Jan. 31, 1960, pp.55-60 re
`References Cited by the Examiner
`lied on.
`UNITED STATES PATENTs
`2,848,714 8/1958 Ring --------------- 343-854
`9/1961 Abbott --------- 343-854 X HERMAN KARL SAALBACH, Primary Examiner.
`3,002,188
`3,063,025 11/1962 Van Atta ---------- 333-10 X
`ESTB
`3,093,826
`6/1963 Fink ------------ gs; to GEORGE N. WESTBY, Examiner.
`
`