US3048843A - Circular antenna array system scanning switch - Google Patents

Circular antenna array system scanning switch Download PDF

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Publication number
US3048843A
US3048843A US794014A US79401459A US3048843A US 3048843 A US3048843 A US 3048843A US 794014 A US794014 A US 794014A US 79401459 A US79401459 A US 79401459A US 3048843 A US3048843 A US 3048843A
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segments
rotor
stator
scanning
segment
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US794014A
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English (en)
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Steiner Fritz
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International Standard Electric Corp
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International Standard Electric Corp
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q3/00—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system
    • H01Q3/24—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching
    • H01Q3/242—Circumferential scanning
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S1/00—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith
    • G01S1/02—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith using radio waves
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S3/00—Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic, or electromagnetic waves, or particle emission, not having a directional significance, are being received
    • G01S3/02—Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic, or electromagnetic waves, or particle emission, not having a directional significance, are being received using radio waves
    • G01S3/14—Systems for determining direction or deviation from predetermined direction
    • G01S3/52—Systems for determining direction or deviation from predetermined direction using a receiving antenna moving, or appearing to move, in a cyclic path to produce a Doppler variation of frequency of the received signal
    • G01S3/54—Systems for determining direction or deviation from predetermined direction using a receiving antenna moving, or appearing to move, in a cyclic path to produce a Doppler variation of frequency of the received signal the apparent movement of the antenna being produced by coupling the receiver cyclically and sequentially to each of several fixed spaced antennas

Definitions

  • the present invention relates to a switching device for the cyclically sequential connection of fixed antenna elements of a circular antenna array to a receiving device for the purpose of determining the direction of incidence of electromagnetic waves.
  • Various methods are known for directional receiving systems, in which a circular antenna array is cyclically scanned by electrical switching means. From the phase modulation of the incoming wave a bearing signal is derived by means of a phase comparison with a reference signal effecting the scanning.
  • a direction finder operating on this principle is preferably designed in the conventional manner as a wide aperture direction finder to keep the bearing errors to a minimum.
  • this proposed directionfinding method has formerly been carried out in such a way that individual antennas are connected sequentially to the receiver by means of switching diodes.
  • switching diodes In the switching of these diodes there are used two trains of pulses, of which one train simulates a rapid forward and backward motion, while the other one simulates a slow and continuously progressive motion of an antenna element.
  • the connection of the antenna element which is carried out in this case electronically, is performed by means of pulse generators of a different repetition rate in combination with delay lines and voltage-dependent resistors, such as the aforementioned diodes arranged in the antenna leadins. In this case, however, the investment in switching equipment is a considerable one.
  • a direction finder of the Doppler type has been known in which a circular antenna array is scanned by means of a capacitively coupled switch and in which the fre quency deviation resulting therefrom is utilized for determining the direction.
  • This system has been described in an article by Fantoni and Benoit, which was published in the IRE Convention Record, part 8, March 19-22, 1956.
  • This system bears the disadvantage which is already well known in direction finding systems of the Doppler type, where slow scanning of the antenna system is used, namely, the frequency deviation or lowfrequency bearing voltage obtained therefrom is very small and, therefore, incapable of being utilized for the direction determination purpose.
  • the group delay produced by the receiver is within the range of the frequency variation and therefore causes considerable bearing errors.
  • the scanning switch according to this invent-ion is for a circular antenna array which simulates the motion of an antenna element.
  • this scanning switch is utilized from the simulation of successive-step motions with the aid of a stator and a rotor in which the order of succession of the scanning operations of N input lines with the numerals n in successive scanning steps and with the numerals in corresponding to an assignment.
  • N switch segments at an equally spaced relation d
  • FIG. 1 shows a Doppler-type direction finder system employing a capacitive scanning switch according to the invention for simulating a simple
  • FIG. 2 shows another embodiment of the scanning switch according to the idea of the invent-ion, which operates on an inductive coupling principle
  • FIG. 3a schematically shows part of the stator arrangement
  • FIG. 3b schematically shows a rotor and stator arrangement for effecting a forward U-step motion of the antenna
  • FIG. 3c schematically shows a rotor and stator arrangement for effecting a backward mit-step motion of the antenna
  • FIG. 4 shows the electrical equivalent circuit diagram of the scanning switch extending from the connecting point of the antennas to the receiver inlet
  • FIG. 5 shows one kind of the apparent antenna motion (sinusoidal) as plotted on a time base (milliseconds).
  • FIG. 6 shows the amplitude modulation resulting on account of the scanning of the antenna array according to FIG. 5 at the output of the receiver 17 in FIG. 1, and
  • FIG. 7 shows a general shape of the antenna motion in a graphical representation.
  • the direction finder as shown in principle in FIG. 1 of the accompanying drawings is equipped with a capacitive scanning switch which according to the invention allows a very simple vocational-step scanning motion which for purposes of explanation is in this particular instance three steps in the forward direction and two steps in the backward direction.
  • the example of this simple type of civil-step scanning motion is illustrated graphically in FIG. 7.
  • any sequential vocational-step scanning motion can be used consisting of a fixed number of integral steps in one direction followed by a fixed number of steps in the opposite direction other than the number of steps used in the first direction.
  • the capacitive switch segments of the stator 2 and rotor 7 may also be adapted to a photoelectric arrangement where the corresponding segments would then be holes through which a light ray may pass for controlling a photelectric cell.
  • the circular antenna-array system 1 comprising e.g. l2 antenna elements, each of which is connected via cable with one segment 3 of the stator 2.
  • the stator 22 there are also provided just as many aligned collector segments 4, all of which are conduetively connected with each other at the point P.
  • a cable 5 leading to the input of a receiver 17.
  • the rotor a driven by motor 14- is mounted a slight distance from the stator 2 and comprises the segments 7 consisting of two parts illustrated in FIG. 1 and which are connected with each other by means of small inductances.
  • the stator segments, as well as the collector and rotor segments are all of the same width.
  • An alternating-current voltage will be produced in winding 9 corresponding to the rapid scanning of the antenna array.
  • This AC. voltage is used as the phase-locked reference signal.
  • the winding 9 of the phonic wheel 8 is angularly displaceable by a small amount, so that the phase of this reference signal is adjustable by a desired amount.
  • the voltage produced by means of the phonic wheel 8 is fed via slip-rings or collector rings 31 to the rotor winding 13 of a ring-type goniorneter.
  • the stator Winding 12 of the goniometer is closed in itself and has four tappings which are staggered by 90 From two opposing tappings there are respectively taken off two voltages of the shape as shown in FIG. 6.
  • the envelopes of these voltages are phase-shifted with respect to each other by 90.
  • the envelope of the output voltage of the receiver 17 likewise has the shape, as indicated in FIG. 6. But this voltage is phase-shifted with respect to the other envelopes by the corresponding direction of incidence of the received electromagnetic waves.
  • Each of the two reference signals which are phase-shifted by 96 is now fed in the conventional manner via conductor leads l5 and 16 together with the signal containing the bearing information from receiver 17, via line 18 to a network enabling a product formation and comprising a conventional type of phase comparator indicator 19.
  • the DC. component of each of these products is then in proportion to the sine or the cosine respectively of the angle of incidence of the wave front.
  • FIGS. 3a to 312 may also be understood to be e.g. a cylindrical arrangement developed on a plane, in which case the stator and collector segments 3, 4 are arranged on an outer cylinder, and the rotor segments 7 (see FIG. 1) may be arranged on an internal second cylinder.
  • the stator of the scanning switch is provided with stator segments 3 corresponding to the number of antennas to be commutated. Each of these stator segments 3 is connected with its associated antenna by means of a concentric cable. Assigned to these stator segments, but insulated therefrom are the collector segments 4 which are equal in number and which are provided on the same carrier component. Collector segments 4 are interconnected at point P and lead to the input of receiver 17. At a small distance opposite this stationary stator component 2 there is arranged a rotating component comprising a small number of segments 7, of which each consists of two parts as is shown in FIG. 1. One part bridges or overlaps the stator segment 3, while the other part overlaps the corresponding collector segment 4.
  • stator and the collector segments are filled with metal coatings, as is indicated by the shaded portions in FIG. 3a.
  • these metal coatings are connected to a ground conductor.
  • ground conductors accompanying both the stator and collector segments are arranged at such a distance from the respective segments that they have the same characteristic impedance, as that of the coaxial cable leading to the antenna, namely, 60 ohms.
  • the continuously extending ground conductors also allow the energy received by the antenna to be only transferred to the collector segments 4, whenever a rotor segment bridges or overlaps both a stator segment 3 and a collector segment 4.
  • the rotor segments 7 are capacitively grounded when not positioned opposite to a stator and collector segment.
  • the characteristic impedance of the scanning switch is approximately equal to that of the cable leading to the antenna, the currents can be transferred in a continuous line from the antenna via the stator segment 3, the rotor segment 7 and the collector segment 4 to the input of the receiver 17.
  • each rotor seg- -ment 7 are respectively connected with each other by means of a small inductance 22 constituting, together with the transmission capacitance of the two movable parts of the rotor-segments with respect to the stationary segments, at series-resonant circuit having its resonant frequency near the middle of the frequency range to be transmitted.
  • collector segments 4 connected to each other and leading to the receiver 17 are connected to ground by a small inductance 24 which, together with the switch capacitances (segments 4, FIG. 3a, to ground) form a parallel-resonant circuit having its resonant frequency near the middle of the frequency range to be transmitted.
  • FIG. 4 The equivalent diagram of the circuit arrangement is shown in FIG. 4.
  • the capacitor 21 corresponds to the capacitance of stator segment 3 (FIG. 3a) with respect to rotor segment 7, see FIG. 1, part A (FIG. 31))
  • the capacitor 23 corresponds to the capacitance of collector segment 4 (FIG. 3a) with respect to segment 7, see FIG. 1, part B (FIG. 31)).
  • These two series-arranged capacitors, together with inductance 22, form the above-mentioned series-resonant circuit
  • the capacitor 25, which is formed by the switch capacitance of the collector segments 4 (FIG. 3a) to ground together with inductance 24 represent the parallel-resonant circuit.
  • FIGS. 3a to 30 the arrangement of the segments on stator 3 and rotor 4 will be better understood with respect to the mit-step scanning motion of this invention.
  • the distance d shown on FIG. 3a corresponds to the mutual spacing between the central line of adjacent stator segments.
  • the scanning of the individual antenna elements is now supposed to proceed in such a way that upon completion of one period p there is coupled the next antenna element so that the number of input lines or antennas, scanned during the scanning step m-l-p, is by unity greater than the number of the lines scanned during the scanning step m. It should be understood that this condition applies to each arbitrary point of the curve or to each arbitrary number n of the input lines respectively.
  • the width of the individual rotor segment 7 likewise results from this formula, in that in the most simple case it is equal to that of the stator segments.
  • m width of the individual rotor segment 7
  • m f(m)
  • stator segments In the assumed and most simple example with the three scanning steps in the forward direction and two scanning steps in the backward direction the stator segments have a width of /5 (one-fifth) of the spacing (d), and a mutual spacing of /5 between adjacent segments.
  • the rotor segments as illustrated in FIG. 3b likewise has a width of /5 and, in accordance with the formula of proportion has a spacing between adjacent rotor segments of
  • FIG. 3b where the rotor segments are aligned in such a manner that rotor segment A is positioned one step to the left of the first stator segment M.
  • stator segment A in its first step will be directly beneath stator segment M.
  • stator segments A, B and C will be positioned in succession directly beneath a succession of stator segments MNO etc.
  • the following table will illustrate which of the stator and rotor segments will be capacitively coupled as the rotor 7 progresses clockwise in a step by-step motion.
  • stator segment M is coincident with rotor segment A in the first step and stator segment N Will be coincident with rotor segment B in the second step.
  • stator segment N Will be coincident with rotor segment B in the second step.
  • the rotor 6 is continuously moving in a clockwise direction. The segments of the rotor are so spaced that the resultant effect of the scanning motion is to connect each antenna element to the receiver in a mit-step order.
  • the motion of the capacitive scanning switch is such that initially antenna elements 1, 2 and 3 are successively scanned, and then followed by a second scan of antenna elements 2, 3 and 4-, which is further followed by a third scan of antenna elements 3, 4 and 5 etc., until the entire antenna array has been scanned.
  • this type of successive-step scanning motion produces a slow continuous scanning which corresponds to the number of rotations or the frequency of the rotor 7 which was previously stated to be 50 c.p.s., having superimposed thereon a rapid oscillating motion of a frequency of about 1500 c.p.s. in a sector of about i45.
  • FIG. 3c illustrates the backward crawl-step scanning motion.
  • the mutual spacing between adjacent rotor segments 7 is 7 of the mutual spacing of the stator and the width of each rotor segment is /5.
  • the rotor segments are shown initially aligned in such a manner that rotor segment A is positioned two steps to the left of the first stator segment M, and as can be seen from this figure rotor segment C is coincident with a stator segment.
  • rotor segment B will now be coincident with stator segment N, and as the rotor is advanced an additional step rotor segment A will be coincident with stator segment M.
  • the following table will illustrate which of the stator and rotor segments will be capacitively coupled as rotor 7 progresses clockwise successively, in a step-by-step motion.
  • FIG. 2 there is shown another embodiment relating to the scanning switch according to the idea of the invention, which is based on the inductive coupling principle.
  • the individual antennas are applied by means of capacitors 28 28 to coupling coils 26 26 the other winding ends of which are connected to ground. Between the individual coils there are provided shielding walls 31, and each coupling circuit consisting of the capacitor 28 and the inductance 26 is balanced to seriesresonance for the medium frequency range to be transmitted. On the same base there are mounted additional coupling coils 27 -27 which are connected in parallel and are tuned by means of capacitor 29 for impedance matching at the medium operating frequency range. One end of the coupling coil is applied to the ground while the other end is connected to the point P and to the receiver 17 (FIG. 1).
  • a strong or intensive coupling of the coils 26 and 27 and, consequently, a transfer of the antenna energy to the receiver is accomplished with the aid of ferro-magnetic elements 30 3i which are mounted to a rotor in accordance with the points of view 8 relating to the proportion and arrangement given in the exampie relating to the capacitive scanning switch described hereinbefore.
  • the whole arrangement is also suitable for use with transmitters, when the reference signal is transmitted as well, eg via an auxiliary carrier or in an amplitude-modulated fashion.
  • a scanning switch comprising a stator having an outer portion and an inner portion, a first group of segments radially positioned about said outer portion and spaced from each other, a second group of segments corresponding in number to the segments of said first group and aligned therewith, one of said group of segments having their segments interconnected, said second group of segments radially positioned about said inner portion and spaced from said first group of segments and from each other, a plurality of input lines equal in number to the number of segments in a group, means to connect said input lines with the corresponding segment of one of said groups, an output line, means to connect an output line with all of the segments of the other group, a rotor having a radially positioned rotor segment adapted to be aligned progressively with said segments of said first and second groups as the rotor is rotated and positioned in a coupling relation thereto, said rotor segment bridging the space between said segments of said first and second groups to provide coupling therebetween, and means for rotating said rotor to provide successive and
  • a scanning switch as defined in claim 1 further comprising means connected to the rotor for producing a variable reference voltage, and means for comparing said reference voltage with the signal produced on said output line for producing an indication.
  • a scanning switch as defined in claim 1 comprising an antenna array raving elements circularly spaced a predetermined distance from each other corresponding to the number of segments in a group, and means for connecting said plurality of input lines to said antenna elements.
  • a scanning switch as defined in claim 1 further comprising means for providing a plurality of input line scans for each rotation of the rotor, the cycles of each scan having a fixed number of steps, said rotor comprising a plurality of segments said rotor segments having a different mutual spacing than the mutual spacing of the stator segments, the mutual spacing of the rotor segments differing from that of the mutual spacing of the stator segments by an amount equal to the distance traversed by said rotor segment in one step.
  • a scanning switch comprising a stator having an outer portion and an inner portion, a first group of segments radially positioned about said outer portion and spaced from each other, a second group of segments corresponding in number to the segments of said first group and aligned therewith, one of said group of segments having their segments interconnected, said second group of segments radially positioned about said inner portion and spaced from said first group of segments and from each other, a plurality of input lines equal in number to the number of segments in a group, means to connect said input lines with the corresponding segment of one of said groups, an output line, means to connect an input line with all of the segments of the other group, a shielding metallic member positioned between a pair of aligned segments of the first and second groups and the next adjacent pair of segments, said member being connected to ground and spaced a predetermined distance from said pairs of segments so that the characteristic impedance from the segments to the shielding member is approximately equal to the impedance of the input lines, an inductance connected between output line and the segments connected thereto to
  • a scanning switch comprising a stator having an outer portion and an inner portion, a first group of segments radially positioned about said outer portion and spaced from each other, a second group of segments corresponding in number to the segments of said first group and aligned therewith, one of said group of segments having their segments interconnected, said second group of segments radially positioned about said inner portion and spaced from said first group of segments and from each other, a plurality of input lines equal in number to the number of segments in a group, means to connect said input lines with the corresponding segment of one of said groups, an output line, means to connect an output line with all of the segments of the other group, a rotor having a radially positioned rotor segment adapted to be aligned progressively with said segments of said first and second groups as the rotor is rotated and positioned in a coupling relation thereto, said rotor segment bridging the space between said segments of said first and second groups to provide coupling therebetween, said rotor seg ment further comprising two
  • a scanning switch comprising a stator having an outer portion and an inner portion, a first group of segments radially positioned about said outer portion and spaced from each other, a second group of segments corresponding in number to the segments of said first group and aligned therewith, one of said group of segments having their segments interconnected, said second group of segments radially positioned about said inner portion and spaced from said first group of segments and trom each other, a plurality of input lines equal in number to the number of segments in a group, means to connect said input lines with the corresponding segment of one of said groups, an output line, means to connect an output line with all of the segments of the other group, a rotor having a radially positioned rotor segment adapted to be aligned progressively with said segments of said first and second groups as the rotor is rotated and positioned in a coupling relation thereto, said rotor segment bridging the space between said segments of said first and second groups to provide coupling therebet'ween, the coupling between said stat
  • a scanning switch for a circular antenna array having a plurality of antennas for simulating antenna element motion comprising a stator and a rotor, said stator having a first group of segments equal in number to said plurality of antennas and spaced equidistant about a common point, a second group of segments corresponding in number to the segments or" said first group and disposed in spaced alignment therewith, means coupling together the segments of said second group, means coupling each of said antenna elements to a segment of said first group, said rotor comprising a plurality of segments disposed thereon and adapted for alignment with said aligned segments of said first and second groups in bridging relationship thereto, means for rotating said rotor relative to said stator to provide successive and retrogressive coupling of said segments of said first and second groups whereby signals received at said antenna array are coupled from the segments of said first group to the segments of said second group in said successive and retrogressive manner.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Variable-Direction Aerials And Aerial Arrays (AREA)
US794014A 1958-02-22 1959-02-18 Circular antenna array system scanning switch Expired - Lifetime US3048843A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEL29741A DE1100727B (de) 1958-02-22 1958-02-22 Einrichtung zum zyklischen Anschalten der Einzelantennen eines Kreisantennen-systemsan einen Peilempfaenger oder eine Funkfeuer-Sendeeinrichtung

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US3048843A true US3048843A (en) 1962-08-07

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US794014A Expired - Lifetime US3048843A (en) 1958-02-22 1959-02-18 Circular antenna array system scanning switch

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US (1) US3048843A (xx)
BE (1) BE575996A (xx)
CH (1) CH374728A (xx)
DE (1) DE1100727B (xx)
FR (1) FR1224309A (xx)
GB (1) GB851007A (xx)
NL (2) NL236394A (xx)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1192709B (de) * 1961-01-17 1965-05-13 Servo Corp Of America Schaltvorrichtung zur aufeinanderfolgenden Anschaltung einer einzelnen Antenne aus einer Mehrzahl kreisfoermig angeordneter Antennen

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2457127A (en) * 1945-06-27 1948-12-28 Standard Telephones Cables Ltd Antenna system
US2769159A (en) * 1954-10-26 1956-10-30 Raytheon Mfg Co Capacitive commutators
US2902673A (en) * 1953-04-10 1959-09-01 Donald G C Hare Selective signalling device
US2953782A (en) * 1955-05-04 1960-09-20 Marconi Wireless Telegraph Co Receiving aerial systems
US2961655A (en) * 1957-06-19 1960-11-22 Magnues A Magnuson Synthetic radar target generator

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2457127A (en) * 1945-06-27 1948-12-28 Standard Telephones Cables Ltd Antenna system
US2902673A (en) * 1953-04-10 1959-09-01 Donald G C Hare Selective signalling device
US2769159A (en) * 1954-10-26 1956-10-30 Raytheon Mfg Co Capacitive commutators
US2953782A (en) * 1955-05-04 1960-09-20 Marconi Wireless Telegraph Co Receiving aerial systems
US2961655A (en) * 1957-06-19 1960-11-22 Magnues A Magnuson Synthetic radar target generator

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CH374728A (de) 1964-01-31
DE1100727B (de) 1961-03-02
GB851007A (en) 1960-10-12
BE575996A (nl) 1959-08-24
FR1224309A (fr) 1960-06-23
NL113556C (xx)
NL236394A (xx)

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